]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/kern_memorystatus.c
xnu-4903.270.47.tar.gz
[apple/xnu.git] / bsd / kern / kern_memorystatus.c
index 13dcc2607c11dc729cd648d1e99bd961711a270b..5c3410624cf99db7f39d92748d3646caab3403f9 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2006-2018 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  *
  */
 #include <kern/task.h>
 #include <kern/thread.h>
 #include <kern/host.h>
+#include <kern/policy_internal.h>
+#include <kern/thread_group.h>
+
+#include <IOKit/IOBSD.h>
+
 #include <libkern/libkern.h>
 #include <mach/coalition.h>
 #include <mach/mach_time.h>
 #include <mach/task.h>
 #include <mach/host_priv.h>
 #include <mach/mach_host.h>
+#include <os/log.h>
 #include <pexpert/pexpert.h>
 #include <sys/coalition.h>
 #include <sys/kern_event.h>
 #include <sys/proc.h>
 #include <sys/proc_info.h>
+#include <sys/reason.h>
 #include <sys/signal.h>
 #include <sys/signalvar.h>
 #include <sys/sysctl.h>
 #include <vm/vm_map.h>
 #endif /* CONFIG_FREEZE */
 
-#include <sys/kern_memorystatus.h> 
+#include <sys/kern_memorystatus.h>
+
+#include <mach/machine/sdt.h>
+#include <libkern/section_keywords.h>
+#include <stdatomic.h>
 
-#if CONFIG_JETSAM
 /* For logging clarity */
-static const char *jetsam_kill_cause_name[] = {
-       ""                      ,
-       "jettisoned"            ,       /* kMemorystatusKilled                  */
-       "highwater"             ,       /* kMemorystatusKilledHiwat             */
-       "vnode-limit"           ,       /* kMemorystatusKilledVnodes            */
-       "vm-pageshortage"       ,       /* kMemorystatusKilledVMPageShortage    */
-       "vm-thrashing"          ,       /* kMemorystatusKilledVMThrashing       */
-       "fc-thrashing"          ,       /* kMemorystatusKilledFCThrashing       */
-       "per-process-limit"     ,       /* kMemorystatusKilledPerProcessLimit   */
-       "diagnostic"            ,       /* kMemorystatusKilledDiagnostic        */
-       "idle-exit"             ,       /* kMemorystatusKilledIdleExit          */
+static const char *memorystatus_kill_cause_name[] = {
+       "",                                                                             /* kMemorystatusInvalid                                                 */
+       "jettisoned",                                                   /* kMemorystatusKilled                                                  */
+       "highwater",                                                            /* kMemorystatusKilledHiwat                                             */
+       "vnode-limit",                                                  /* kMemorystatusKilledVnodes                                    */
+       "vm-pageshortage",                                              /* kMemorystatusKilledVMPageShortage                    */
+       "proc-thrashing",                                               /* kMemorystatusKilledProcThrashing                             */
+       "fc-thrashing",                                                 /* kMemorystatusKilledFCThrashing                               */
+       "per-process-limit",                                            /* kMemorystatusKilledPerProcessLimit                   */
+       "disk-space-shortage",                                  /* kMemorystatusKilledDiskSpaceShortage                 */
+       "idle-exit",                                                            /* kMemorystatusKilledIdleExit                                  */
+       "zone-map-exhaustion",                                  /* kMemorystatusKilledZoneMapExhaustion                 */
+       "vm-compressor-thrashing",                              /* kMemorystatusKilledVMCompressorThrashing             */
+       "vm-compressor-space-shortage",                 /* kMemorystatusKilledVMCompressorSpaceShortage */
 };
 
+static const char *
+memorystatus_priority_band_name(int32_t priority)
+{
+       switch (priority) {
+       case JETSAM_PRIORITY_FOREGROUND:
+               return "FOREGROUND";
+       case JETSAM_PRIORITY_AUDIO_AND_ACCESSORY:
+               return "AUDIO_AND_ACCESSORY";
+       case JETSAM_PRIORITY_CONDUCTOR:
+               return "CONDUCTOR";
+       case JETSAM_PRIORITY_HOME:
+               return "HOME";
+       case JETSAM_PRIORITY_EXECUTIVE:
+               return "EXECUTIVE";
+       case JETSAM_PRIORITY_IMPORTANT:
+               return "IMPORTANT";
+       case JETSAM_PRIORITY_CRITICAL:
+               return "CRITICAL";
+       }
+
+       return "?";
+}
+
 /* Does cause indicate vm or fc thrashing? */
 static boolean_t
-is_thrashing(unsigned cause)
+is_reason_thrashing(unsigned cause)
 {
        switch (cause) {
-       case kMemorystatusKilledVMThrashing:
        case kMemorystatusKilledFCThrashing:
+       case kMemorystatusKilledVMCompressorThrashing:
+       case kMemorystatusKilledVMCompressorSpaceShortage:
                return TRUE;
        default:
                return FALSE;
        }
 }
 
-/* Callback into vm_compressor.c to signal that thrashing has been mitigated. */
-extern void vm_thrashing_jetsam_done(void);
-#endif
+/* Is the zone map almost full? */
+static boolean_t
+is_reason_zone_map_exhaustion(unsigned cause)
+{
+       if (cause == kMemorystatusKilledZoneMapExhaustion) {
+               return TRUE;
+       }
+       return FALSE;
+}
+
+/*
+ * Returns the current zone map size and capacity to include in the jetsam snapshot.
+ * Defined in zalloc.c
+ */
+extern void get_zone_map_size(uint64_t *current_size, uint64_t *capacity);
+
+/*
+ * Returns the name of the largest zone and its size to include in the jetsam snapshot.
+ * Defined in zalloc.c
+ */
+extern void get_largest_zone_info(char *zone_name, size_t zone_name_len, uint64_t *zone_size);
 
 /* These are very verbose printfs(), enable with
  * MEMORYSTATUS_DEBUG_LOG
@@ -117,56 +172,48 @@ do {                                              \
  * soon be in effect down in the ledgers.
  */
 
-#define SET_ACTIVE_LIMITS_LOCKED(p, limit, is_fatal)                   \
-MACRO_BEGIN                                                            \
-(p)->p_memstat_memlimit_active = (limit);                              \
-   (p)->p_memstat_state &= ~P_MEMSTAT_MEMLIMIT_ACTIVE_EXC_TRIGGERED;   \
-   if (is_fatal) {                                                     \
-          (p)->p_memstat_state |= P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL;     \
-   } else {                                                            \
-          (p)->p_memstat_state &= ~P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL;    \
-   }                                                                   \
+#define SET_ACTIVE_LIMITS_LOCKED(p, limit, is_fatal)                    \
+MACRO_BEGIN                                                             \
+(p)->p_memstat_memlimit_active = (limit);                               \
+   if (is_fatal) {                                                      \
+          (p)->p_memstat_state |= P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL;     \
+   } else {                                                             \
+          (p)->p_memstat_state &= ~P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL;    \
+   }                                                                    \
 MACRO_END
 
-#define SET_INACTIVE_LIMITS_LOCKED(p, limit, is_fatal)                 \
-MACRO_BEGIN                                                            \
-(p)->p_memstat_memlimit_inactive = (limit);                            \
-   (p)->p_memstat_state &= ~P_MEMSTAT_MEMLIMIT_INACTIVE_EXC_TRIGGERED; \
-   if (is_fatal) {                                                     \
-          (p)->p_memstat_state |= P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL;   \
-   } else {                                                            \
-          (p)->p_memstat_state &= ~P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL;  \
-   }                                                                   \
+#define SET_INACTIVE_LIMITS_LOCKED(p, limit, is_fatal)                  \
+MACRO_BEGIN                                                             \
+(p)->p_memstat_memlimit_inactive = (limit);                             \
+   if (is_fatal) {                                                      \
+          (p)->p_memstat_state |= P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL;   \
+   } else {                                                             \
+          (p)->p_memstat_state &= ~P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL;  \
+   }                                                                    \
 MACRO_END
 
-#define CACHE_ACTIVE_LIMITS_LOCKED(p, trigger_exception)               \
-MACRO_BEGIN                                                            \
-(p)->p_memstat_memlimit = (p)->p_memstat_memlimit_active;              \
-   if ((p)->p_memstat_state & P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL) {       \
-          (p)->p_memstat_state |= P_MEMSTAT_FATAL_MEMLIMIT;            \
-   } else {                                                            \
-          (p)->p_memstat_state &= ~P_MEMSTAT_FATAL_MEMLIMIT;           \
-   }                                                                   \
-   if ((p)->p_memstat_state & P_MEMSTAT_MEMLIMIT_ACTIVE_EXC_TRIGGERED) { \
-          trigger_exception = FALSE;                                   \
-   } else {                                                            \
-          trigger_exception = TRUE;                                    \
-   }                                                                   \
+#define CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal)                         \
+MACRO_BEGIN                                                             \
+(p)->p_memstat_memlimit = (p)->p_memstat_memlimit_active;               \
+   if ((p)->p_memstat_state & P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL) {        \
+          (p)->p_memstat_state |= P_MEMSTAT_FATAL_MEMLIMIT;            \
+          is_fatal = TRUE;                                             \
+   } else {                                                             \
+          (p)->p_memstat_state &= ~P_MEMSTAT_FATAL_MEMLIMIT;           \
+          is_fatal = FALSE;                                            \
+   }                                                                    \
 MACRO_END
 
-#define CACHE_INACTIVE_LIMITS_LOCKED(p, trigger_exception)             \
-MACRO_BEGIN                                                            \
-(p)->p_memstat_memlimit = (p)->p_memstat_memlimit_inactive;            \
-   if ((p)->p_memstat_state & P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL) {     \
-          (p)->p_memstat_state |= P_MEMSTAT_FATAL_MEMLIMIT;            \
-   } else {                                                            \
-          (p)->p_memstat_state &= ~P_MEMSTAT_FATAL_MEMLIMIT;           \
-   }                                                                   \
-   if ((p)->p_memstat_state & P_MEMSTAT_MEMLIMIT_INACTIVE_EXC_TRIGGERED) { \
-          trigger_exception = FALSE;                                   \
-   } else {                                                            \
-          trigger_exception = TRUE;                                    \
-   }                                                                   \
+#define CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal)                       \
+MACRO_BEGIN                                                             \
+(p)->p_memstat_memlimit = (p)->p_memstat_memlimit_inactive;             \
+   if ((p)->p_memstat_state & P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL) {      \
+          (p)->p_memstat_state |= P_MEMSTAT_FATAL_MEMLIMIT;            \
+          is_fatal = TRUE;                                             \
+   } else {                                                             \
+          (p)->p_memstat_state &= ~P_MEMSTAT_FATAL_MEMLIMIT;           \
+          is_fatal = FALSE;                                            \
+   }                                                                    \
 MACRO_END
 
 
@@ -177,6 +224,7 @@ unsigned long critical_threshold_percentage = 5;
 unsigned long idle_offset_percentage = 5;
 unsigned long pressure_threshold_percentage = 15;
 unsigned long freeze_threshold_percentage = 50;
+unsigned long policy_more_free_offset_percentage = 5;
 
 /* General memorystatus stuff */
 
@@ -186,31 +234,39 @@ static lck_mtx_t memorystatus_klist_mutex;
 static void memorystatus_klist_lock(void);
 static void memorystatus_klist_unlock(void);
 
-static uint64_t memorystatus_idle_delay_time = 0;
+static uint64_t memorystatus_sysprocs_idle_delay_time = 0;
+static uint64_t memorystatus_apps_idle_delay_time = 0;
 
 /*
  * Memorystatus kevents
  */
 
-static int filt_memorystatusattach(struct knote *kn);
+static int filt_memorystatusattach(struct knote *kn, struct kevent_internal_s *kev);
 static void filt_memorystatusdetach(struct knote *kn);
 static int filt_memorystatus(struct knote *kn, long hint);
+static int filt_memorystatustouch(struct knote *kn, struct kevent_internal_s *kev);
+static int filt_memorystatusprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
 
-struct filterops memorystatus_filtops = {
+SECURITY_READ_ONLY_EARLY(struct filterops) memorystatus_filtops = {
        .f_attach = filt_memorystatusattach,
        .f_detach = filt_memorystatusdetach,
        .f_event = filt_memorystatus,
+       .f_touch = filt_memorystatustouch,
+       .f_process = filt_memorystatusprocess,
 };
 
 enum {
        kMemorystatusNoPressure = 0x1,
        kMemorystatusPressure = 0x2,
-       kMemorystatusLowSwap = 0x4
+       kMemorystatusLowSwap = 0x4,
+       kMemorystatusProcLimitWarn = 0x8,
+       kMemorystatusProcLimitCritical = 0x10
 };
 
 /* Idle guard handling */
 
-static int32_t memorystatus_scheduled_idle_demotions = 0;
+static int32_t memorystatus_scheduled_idle_demotions_sysprocs = 0;
+static int32_t memorystatus_scheduled_idle_demotions_apps = 0;
 
 static thread_call_t memorystatus_idle_demotion_call;
 
@@ -219,47 +275,266 @@ static void memorystatus_schedule_idle_demotion_locked(proc_t p, boolean_t set_s
 static void memorystatus_invalidate_idle_demotion_locked(proc_t p, boolean_t clean_state);
 static void memorystatus_reschedule_idle_demotion_locked(void);
 
-static void memorystatus_update_priority_locked(proc_t p, int priority, boolean_t head_insert);
+static void memorystatus_update_priority_locked(proc_t p, int priority, boolean_t head_insert, boolean_t skip_demotion_check);
+
+int memorystatus_update_priority_for_appnap(proc_t p, boolean_t is_appnap);
+
+vm_pressure_level_t convert_internal_pressure_level_to_dispatch_level(vm_pressure_level_t);
 
 boolean_t is_knote_registered_modify_task_pressure_bits(struct knote*, int, task_t, vm_pressure_level_t, vm_pressure_level_t);
+void memorystatus_klist_reset_all_for_level(vm_pressure_level_t pressure_level_to_clear);
 void memorystatus_send_low_swap_note(void);
 
-int memorystatus_wakeup = 0;
-
 unsigned int memorystatus_level = 0;
-unsigned int memorystatus_early_boot_level = 0;
 
 static int memorystatus_list_count = 0;
 
+
 #define MEMSTAT_BUCKET_COUNT (JETSAM_PRIORITY_MAX + 1)
 
 typedef struct memstat_bucket {
-    TAILQ_HEAD(, proc) list;
-    int count;
+       TAILQ_HEAD(, proc) list;
+       int count;
 } memstat_bucket_t;
 
 memstat_bucket_t memstat_bucket[MEMSTAT_BUCKET_COUNT];
 
+int memorystatus_get_proccnt_upto_priority(int32_t max_bucket_index);
+
 uint64_t memstat_idle_demotion_deadline = 0;
 
+int system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+int applications_aging_band = JETSAM_PRIORITY_IDLE;
+
+#define isProcessInAgingBands(p)        ((isSysProc(p) && system_procs_aging_band && (p->p_memstat_effectivepriority == system_procs_aging_band)) || (isApp(p) && applications_aging_band && (p->p_memstat_effectivepriority == applications_aging_band)))
+
+/*
+ * Checking the p_memstat_state almost always requires the proc_list_lock
+ * because the jetsam thread could be on the other core changing the state.
+ *
+ * App -- almost always managed by a system process. Always have dirty tracking OFF. Can include extensions too.
+ * System Processes -- not managed by anybody. Always have dirty tracking ON. Can include extensions (here) too.
+ */
+#define isApp(p)                        ((p->p_memstat_state & P_MEMSTAT_MANAGED) || ! (p->p_memstat_dirty & P_DIRTY_TRACK))
+#define isSysProc(p)                    ( ! (p->p_memstat_state & P_MEMSTAT_MANAGED) || (p->p_memstat_dirty & P_DIRTY_TRACK))
+
+#define kJetsamAgingPolicyNone                          (0)
+#define kJetsamAgingPolicyLegacy                        (1)
+#define kJetsamAgingPolicySysProcsReclaimedFirst        (2)
+#define kJetsamAgingPolicyAppsReclaimedFirst            (3)
+#define kJetsamAgingPolicyMax                           kJetsamAgingPolicyAppsReclaimedFirst
+
+unsigned int jetsam_aging_policy = kJetsamAgingPolicyLegacy;
+
+extern int corpse_for_fatal_memkill;
+extern unsigned long total_corpses_count(void) __attribute__((pure));
+extern void task_purge_all_corpses(void);
+extern uint64_t vm_purgeable_purge_task_owned(task_t task);
+boolean_t memorystatus_allowed_vm_map_fork(task_t);
+#if DEVELOPMENT || DEBUG
+void memorystatus_abort_vm_map_fork(task_t);
+#endif
+
+#if 0
+
+/* Keeping around for future use if we need a utility that can do this OR an app that needs a dynamic adjustment. */
+
+static int
+sysctl_set_jetsam_aging_policy SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+
+       int error = 0, val = 0;
+       memstat_bucket_t *old_bucket = 0;
+       int old_system_procs_aging_band = 0, new_system_procs_aging_band = 0;
+       int old_applications_aging_band = 0, new_applications_aging_band = 0;
+       proc_t p = NULL, next_proc = NULL;
+
+
+       error = sysctl_io_number(req, jetsam_aging_policy, sizeof(int), &val, NULL);
+       if (error || !req->newptr) {
+               return error;
+       }
+
+       if ((val < 0) || (val > kJetsamAgingPolicyMax)) {
+               printf("jetsam: ordering policy sysctl has invalid value - %d\n", val);
+               return EINVAL;
+       }
+
+       /*
+        * We need to synchronize with any potential adding/removal from aging bands
+        * that might be in progress currently. We use the proc_list_lock() just for
+        * consistency with all the routines dealing with 'aging' processes. We need
+        * a lighterweight lock.
+        */
+       proc_list_lock();
+
+       old_system_procs_aging_band = system_procs_aging_band;
+       old_applications_aging_band = applications_aging_band;
+
+       switch (val) {
+       case kJetsamAgingPolicyNone:
+               new_system_procs_aging_band = JETSAM_PRIORITY_IDLE;
+               new_applications_aging_band = JETSAM_PRIORITY_IDLE;
+               break;
+
+       case kJetsamAgingPolicyLegacy:
+               /*
+                * Legacy behavior where some daemons get a 10s protection once and only before the first clean->dirty->clean transition before going into IDLE band.
+                */
+               new_system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+               new_applications_aging_band = JETSAM_PRIORITY_IDLE;
+               break;
+
+       case kJetsamAgingPolicySysProcsReclaimedFirst:
+               new_system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+               new_applications_aging_band = JETSAM_PRIORITY_AGING_BAND2;
+               break;
+
+       case kJetsamAgingPolicyAppsReclaimedFirst:
+               new_system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND2;
+               new_applications_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+               break;
+
+       default:
+               break;
+       }
+
+       if (old_system_procs_aging_band && (old_system_procs_aging_band != new_system_procs_aging_band)) {
+               old_bucket = &memstat_bucket[old_system_procs_aging_band];
+               p = TAILQ_FIRST(&old_bucket->list);
+
+               while (p) {
+                       next_proc = TAILQ_NEXT(p, p_memstat_list);
+
+                       if (isSysProc(p)) {
+                               if (new_system_procs_aging_band == JETSAM_PRIORITY_IDLE) {
+                                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+                               }
+
+                               memorystatus_update_priority_locked(p, new_system_procs_aging_band, false, true);
+                       }
+
+                       p = next_proc;
+                       continue;
+               }
+       }
+
+       if (old_applications_aging_band && (old_applications_aging_band != new_applications_aging_band)) {
+               old_bucket = &memstat_bucket[old_applications_aging_band];
+               p = TAILQ_FIRST(&old_bucket->list);
+
+               while (p) {
+                       next_proc = TAILQ_NEXT(p, p_memstat_list);
+
+                       if (isApp(p)) {
+                               if (new_applications_aging_band == JETSAM_PRIORITY_IDLE) {
+                                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+                               }
+
+                               memorystatus_update_priority_locked(p, new_applications_aging_band, false, true);
+                       }
+
+                       p = next_proc;
+                       continue;
+               }
+       }
+
+       jetsam_aging_policy = val;
+       system_procs_aging_band = new_system_procs_aging_band;
+       applications_aging_band = new_applications_aging_band;
+
+       proc_list_unlock();
+
+       return 0;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, set_jetsam_aging_policy, CTLTYPE_INT | CTLFLAG_RW,
+    0, 0, sysctl_set_jetsam_aging_policy, "I", "Jetsam Aging Policy");
+#endif /*0*/
+
+static int
+sysctl_jetsam_set_sysprocs_idle_delay_time SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+
+       int error = 0, val = 0, old_time_in_secs = 0;
+       uint64_t old_time_in_ns = 0;
+
+       absolutetime_to_nanoseconds(memorystatus_sysprocs_idle_delay_time, &old_time_in_ns);
+       old_time_in_secs = old_time_in_ns / NSEC_PER_SEC;
+
+       error = sysctl_io_number(req, old_time_in_secs, sizeof(int), &val, NULL);
+       if (error || !req->newptr) {
+               return error;
+       }
+
+       if ((val < 0) || (val > INT32_MAX)) {
+               printf("jetsam: new idle delay interval has invalid value.\n");
+               return EINVAL;
+       }
+
+       nanoseconds_to_absolutetime((uint64_t)val * NSEC_PER_SEC, &memorystatus_sysprocs_idle_delay_time);
+
+       return 0;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_sysprocs_idle_delay_time, CTLTYPE_INT | CTLFLAG_RW,
+    0, 0, sysctl_jetsam_set_sysprocs_idle_delay_time, "I", "Aging window for system processes");
+
+
+static int
+sysctl_jetsam_set_apps_idle_delay_time SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+
+       int error = 0, val = 0, old_time_in_secs = 0;
+       uint64_t old_time_in_ns = 0;
+
+       absolutetime_to_nanoseconds(memorystatus_apps_idle_delay_time, &old_time_in_ns);
+       old_time_in_secs = old_time_in_ns / NSEC_PER_SEC;
+
+       error = sysctl_io_number(req, old_time_in_secs, sizeof(int), &val, NULL);
+       if (error || !req->newptr) {
+               return error;
+       }
+
+       if ((val < 0) || (val > INT32_MAX)) {
+               printf("jetsam: new idle delay interval has invalid value.\n");
+               return EINVAL;
+       }
+
+       nanoseconds_to_absolutetime((uint64_t)val * NSEC_PER_SEC, &memorystatus_apps_idle_delay_time);
+
+       return 0;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_apps_idle_delay_time, CTLTYPE_INT | CTLFLAG_RW,
+    0, 0, sysctl_jetsam_set_apps_idle_delay_time, "I", "Aging window for applications");
+
+SYSCTL_INT(_kern, OID_AUTO, jetsam_aging_policy, CTLTYPE_INT | CTLFLAG_RD, &jetsam_aging_policy, 0, "");
+
 static unsigned int memorystatus_dirty_count = 0;
 
-#if CONFIG_JETSAM
-SYSCTL_INT(_kern, OID_AUTO, max_task_pmem, CTLFLAG_RD|CTLFLAG_LOCKED|CTLFLAG_MASKED, &max_task_footprint_mb, 0, "");
-#endif // CONFIG_JETSAM
+SYSCTL_INT(_kern, OID_AUTO, max_task_pmem, CTLFLAG_RD | CTLFLAG_LOCKED | CTLFLAG_MASKED, &max_task_footprint_mb, 0, "");
 
+#if CONFIG_EMBEDDED
+
+SYSCTL_INT(_kern, OID_AUTO, memorystatus_level, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_level, 0, "");
+
+#endif /* CONFIG_EMBEDDED */
 
 int
 memorystatus_get_level(__unused struct proc *p, struct memorystatus_get_level_args *args, __unused int *ret)
 {
-       user_addr_t     level = 0;
-       
+       user_addr_t     level = 0;
+
        level = args->level;
-       
+
        if (copyout(&memorystatus_level, level, sizeof(memorystatus_level)) != 0) {
                return EFAULT;
        }
-       
+
        return 0;
 }
 
@@ -268,11 +543,14 @@ static proc_t memorystatus_get_next_proc_locked(unsigned int *bucket_index, proc
 
 static void memorystatus_thread(void *param __unused, wait_result_t wr __unused);
 
-/* Jetsam */
+/* Memory Limits */
 
-#if CONFIG_JETSAM
+static int memorystatus_highwater_enabled = 1;  /* Update the cached memlimit data. */
+
+static boolean_t proc_jetsam_state_is_active_locked(proc_t);
+static boolean_t memorystatus_kill_specific_process(pid_t victim_pid, uint32_t cause, os_reason_t jetsam_reason);
+static boolean_t memorystatus_kill_process_sync(pid_t victim_pid, uint32_t cause, os_reason_t jetsam_reason);
 
-static int memorystatus_cmd_set_jetsam_memory_limit(pid_t pid, int32_t high_water_mark, __unused int32_t *retval, boolean_t is_fatal_limit);
 
 static int memorystatus_cmd_set_memlimit_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval);
 
@@ -280,48 +558,46 @@ static int memorystatus_set_memlimit_properties(pid_t pid, memorystatus_memlimit
 
 static int memorystatus_cmd_get_memlimit_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval);
 
-static boolean_t proc_jetsam_state_is_active_locked(proc_t);
+static int memorystatus_cmd_get_memlimit_excess_np(pid_t pid, uint32_t flags, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval);
 
 int proc_get_memstat_priority(proc_t, boolean_t);
 
-/* Kill processes exceeding their limit either under memory pressure (1), or as soon as possible (0) */
-#define LEGACY_HIWATER 1
-
 static boolean_t memorystatus_idle_snapshot = 0;
 
-static int memorystatus_highwater_enabled = 1;  /* Update the cached memlimit data. This should be removed. */
-
 unsigned int memorystatus_delta = 0;
 
-static unsigned int memorystatus_available_pages_critical_base = 0;
-//static unsigned int memorystatus_last_foreground_pressure_pages = (unsigned int)-1;
-static unsigned int memorystatus_available_pages_critical_idle_offset = 0;
-
 /* Jetsam Loop Detection */
-static boolean_t memorystatus_jld_enabled = TRUE;              /* Enables jetsam loop detection on all devices */
-static uint32_t memorystatus_jld_eval_period_msecs = 0;                /* Init pass sets this based on device memory size */
-static int      memorystatus_jld_eval_aggressive_count = 3;    /* Raise the priority max after 'n' aggressive loops */
+static boolean_t memorystatus_jld_enabled = FALSE;              /* Enable jetsam loop detection */
+static uint32_t memorystatus_jld_eval_period_msecs = 0;         /* Init pass sets this based on device memory size */
+static int      memorystatus_jld_eval_aggressive_count = 3;     /* Raise the priority max after 'n' aggressive loops */
 static int      memorystatus_jld_eval_aggressive_priority_band_max = 15;  /* Kill aggressively up through this band */
 
-#if DEVELOPMENT || DEBUG
-/* 
- * Jetsam Loop Detection tunables.
+/*
+ * A FG app can request that the aggressive jetsam mechanism display some leniency in the FG band. This 'lenient' mode is described as:
+ * --- if aggressive jetsam kills an app in the FG band and gets back >=AGGRESSIVE_JETSAM_LENIENT_MODE_THRESHOLD memory, it will stop the aggressive march further into and up the jetsam bands.
+ *
+ * RESTRICTIONS:
+ * - Such a request is respected/acknowledged only once while that 'requesting' app is in the FG band i.e. if aggressive jetsam was
+ * needed and the 'lenient' mode was deployed then that's it for this special mode while the app is in the FG band.
+ *
+ * - If the app is still in the FG band and aggressive jetsam is needed again, there will be no stop-and-check the next time around.
+ *
+ * - Also, the transition of the 'requesting' app away from the FG band will void this special behavior.
  */
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jld_eval_period_msecs, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_jld_eval_period_msecs, 0, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jld_eval_aggressive_count, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_jld_eval_aggressive_count, 0, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jld_eval_aggressive_priority_band_max, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_jld_eval_aggressive_priority_band_max, 0, "");
-#endif /* DEVELOPMENT || DEBUG */
+#define AGGRESSIVE_JETSAM_LENIENT_MODE_THRESHOLD        25
+boolean_t       memorystatus_aggressive_jetsam_lenient_allowed = FALSE;
+boolean_t       memorystatus_aggressive_jetsam_lenient = FALSE;
 
 #if DEVELOPMENT || DEBUG
-static unsigned int memorystatus_jetsam_panic_debug = 0;
-
-static unsigned int memorystatus_jetsam_policy = kPolicyDefault;
-static unsigned int memorystatus_jetsam_policy_offset_pages_diagnostic = 0;
-static unsigned int memorystatus_debug_dump_this_bucket = 0;
-#endif
+/*
+ * Jetsam Loop Detection tunables.
+ */
 
-static unsigned int memorystatus_thread_wasted_wakeup = 0;
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jld_eval_period_msecs, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_jld_eval_period_msecs, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jld_eval_aggressive_count, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_jld_eval_aggressive_count, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jld_eval_aggressive_priority_band_max, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_jld_eval_aggressive_priority_band_max, 0, "");
+#endif /* DEVELOPMENT || DEBUG */
 
 static uint32_t kill_under_pressure_cause = 0;
 
@@ -329,9 +605,12 @@ static uint32_t kill_under_pressure_cause = 0;
  * default jetsam snapshot support
  */
 static memorystatus_jetsam_snapshot_t *memorystatus_jetsam_snapshot;
+static memorystatus_jetsam_snapshot_t *memorystatus_jetsam_snapshot_copy;
 #define memorystatus_jetsam_snapshot_list memorystatus_jetsam_snapshot->entries
 static unsigned int memorystatus_jetsam_snapshot_count = 0;
+static unsigned int memorystatus_jetsam_snapshot_copy_count = 0;
 static unsigned int memorystatus_jetsam_snapshot_max = 0;
+static unsigned int memorystatus_jetsam_snapshot_size = 0;
 static uint64_t memorystatus_jetsam_snapshot_last_timestamp = 0;
 static uint64_t memorystatus_jetsam_snapshot_timeout = 0;
 #define JETSAM_SNAPSHOT_TIMEOUT_SECS 30
@@ -341,21 +620,29 @@ static uint64_t memorystatus_jetsam_snapshot_timeout = 0;
  */
 static memorystatus_jetsam_snapshot_t memorystatus_at_boot_snapshot;
 
+static void memorystatus_init_jetsam_snapshot_locked(memorystatus_jetsam_snapshot_t *od_snapshot, uint32_t ods_list_count);
+static boolean_t memorystatus_init_jetsam_snapshot_entry_locked(proc_t p, memorystatus_jetsam_snapshot_entry_t *entry, uint64_t gencount);
+static void memorystatus_update_jetsam_snapshot_entry_locked(proc_t p, uint32_t kill_cause, uint64_t killtime);
+
 static void memorystatus_clear_errors(void);
-static void memorystatus_get_task_page_counts(task_t task, uint32_t *footprint, uint32_t *max_footprint, uint32_t *max_footprint_lifetime, uint32_t *purgeable_pages);
+static void memorystatus_get_task_page_counts(task_t task, uint32_t *footprint, uint32_t *max_footprint_lifetime, uint32_t *purgeable_pages);
+static void memorystatus_get_task_phys_footprint_page_counts(task_t task,
+    uint64_t *internal_pages, uint64_t *internal_compressed_pages,
+    uint64_t *purgeable_nonvolatile_pages, uint64_t *purgeable_nonvolatile_compressed_pages,
+    uint64_t *alternate_accounting_pages, uint64_t *alternate_accounting_compressed_pages,
+    uint64_t *iokit_mapped_pages, uint64_t *page_table_pages);
+
+static void memorystatus_get_task_memory_region_count(task_t task, uint64_t *count);
+
 static uint32_t memorystatus_build_state(proc_t p);
-static void memorystatus_update_levels_locked(boolean_t critical_only);
 //static boolean_t memorystatus_issue_pressure_kevent(boolean_t pressured);
 
-static boolean_t memorystatus_kill_specific_process(pid_t victim_pid, uint32_t cause);
-static boolean_t memorystatus_kill_top_process(boolean_t any, boolean_t sort_flag, uint32_t cause, int32_t *priority, uint32_t *errors);
-static boolean_t memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr_count, int32_t priority_max, uint32_t *errors);
-#if LEGACY_HIWATER
-static boolean_t memorystatus_kill_hiwat_proc(uint32_t *errors);
-#endif
+static boolean_t memorystatus_kill_top_process(boolean_t any, boolean_t sort_flag, uint32_t cause, os_reason_t jetsam_reason, int32_t *priority, uint32_t *errors);
+static boolean_t memorystatus_kill_top_process_aggressive(uint32_t cause, int aggr_count, int32_t priority_max, uint32_t *errors);
+static boolean_t memorystatus_kill_elevated_process(uint32_t cause, os_reason_t jetsam_reason, unsigned int band, int aggr_count, uint32_t *errors);
+static boolean_t memorystatus_kill_hiwat_proc(uint32_t *errors, boolean_t *purged);
 
 static boolean_t memorystatus_kill_process_async(pid_t victim_pid, uint32_t cause);
-static boolean_t memorystatus_kill_process_sync(pid_t victim_pid, uint32_t cause);
 
 /* Priority Band Sorting Routines */
 static int  memorystatus_sort_bucket(unsigned int bucket_index, int sort_order);
@@ -368,8 +655,6 @@ typedef int (*cmpfunc_t)(const void *a, const void *b);
 extern void qsort(void *a, size_t n, size_t es, cmpfunc_t cmp);
 static int memstat_asc_cmp(const void *a, const void *b);
 
-#endif /* CONFIG_JETSAM */
-
 /* VM pressure */
 
 extern unsigned int    vm_page_free_count;
@@ -378,21 +663,58 @@ extern unsigned int    vm_page_inactive_count;
 extern unsigned int    vm_page_throttled_count;
 extern unsigned int    vm_page_purgeable_count;
 extern unsigned int    vm_page_wire_count;
+#if CONFIG_SECLUDED_MEMORY
+extern unsigned int     vm_page_secluded_count;
+#endif /* CONFIG_SECLUDED_MEMORY */
 
-#if VM_PRESSURE_EVENTS
+#if CONFIG_JETSAM
+unsigned int memorystatus_available_pages = (unsigned int)-1;
+unsigned int memorystatus_available_pages_pressure = 0;
+unsigned int memorystatus_available_pages_critical = 0;
+static unsigned int memorystatus_available_pages_critical_base = 0;
+static unsigned int memorystatus_available_pages_critical_idle_offset = 0;
+
+#if DEVELOPMENT || DEBUG
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_available_pages, 0, "");
+#else
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages, CTLFLAG_RD | CTLFLAG_MASKED | CTLFLAG_LOCKED, &memorystatus_available_pages, 0, "");
+#endif /* DEVELOPMENT || DEBUG */
+
+static unsigned int memorystatus_jetsam_policy = kPolicyDefault;
+unsigned int memorystatus_policy_more_free_offset_pages = 0;
+static void memorystatus_update_levels_locked(boolean_t critical_only);
+static unsigned int memorystatus_thread_wasted_wakeup = 0;
 
-#include "vm_pressure.h"
+/* Callback into vm_compressor.c to signal that thrashing has been mitigated. */
+extern void vm_thrashing_jetsam_done(void);
+static int memorystatus_cmd_set_jetsam_memory_limit(pid_t pid, int32_t high_water_mark, __unused int32_t *retval, boolean_t is_fatal_limit);
 
-extern boolean_t memorystatus_warn_process(pid_t pid, boolean_t critical);
+int32_t max_kill_priority = JETSAM_PRIORITY_MAX;
 
-vm_pressure_level_t memorystatus_vm_pressure_level = kVMPressureNormal;
+#else /* CONFIG_JETSAM */
+
+uint64_t memorystatus_available_pages = (uint64_t)-1;
+uint64_t memorystatus_available_pages_pressure = (uint64_t)-1;
+uint64_t memorystatus_available_pages_critical = (uint64_t)-1;
+
+int32_t max_kill_priority = JETSAM_PRIORITY_IDLE;
+#endif /* CONFIG_JETSAM */
 
-#if CONFIG_MEMORYSTATUS
-unsigned int memorystatus_available_pages = (unsigned int)-1;
-unsigned int memorystatus_available_pages_pressure = 0;
-unsigned int memorystatus_available_pages_critical = 0;
 unsigned int memorystatus_frozen_count = 0;
+unsigned int memorystatus_frozen_processes_max = 0;
+unsigned int memorystatus_frozen_shared_mb = 0;
+unsigned int memorystatus_frozen_shared_mb_max = 0;
+unsigned int memorystatus_freeze_shared_mb_per_process_max = 0; /* Max. MB allowed per process to be freezer-eligible. */
+unsigned int memorystatus_freeze_private_shared_pages_ratio = 2; /* Ratio of private:shared pages for a process to be freezer-eligible. */
 unsigned int memorystatus_suspended_count = 0;
+unsigned int memorystatus_thaw_count = 0;
+unsigned int memorystatus_refreeze_eligible_count = 0; /* # of processes currently thawed i.e. have state on disk & in-memory */
+
+#if VM_PRESSURE_EVENTS
+
+boolean_t memorystatus_warn_process(pid_t pid, __unused boolean_t is_active, __unused boolean_t is_fatal, boolean_t exceeded);
+
+vm_pressure_level_t memorystatus_vm_pressure_level = kVMPressureNormal;
 
 /*
  * We use this flag to signal if we have any HWM offenders
@@ -409,16 +731,53 @@ unsigned int memorystatus_suspended_count = 0;
 boolean_t memorystatus_hwm_candidates = 0;
 
 static int memorystatus_send_note(int event_code, void *data, size_t data_length);
-#endif /* CONFIG_MEMORYSTATUS */
+
+/*
+ * This value is the threshold that a process must meet to be considered for scavenging.
+ */
+#if CONFIG_EMBEDDED
+#define VM_PRESSURE_MINIMUM_RSIZE               6       /* MB */
+#else /* CONFIG_EMBEDDED */
+#define VM_PRESSURE_MINIMUM_RSIZE               10      /* MB */
+#endif /* CONFIG_EMBEDDED */
+
+uint32_t vm_pressure_task_footprint_min = VM_PRESSURE_MINIMUM_RSIZE;
+
+#if DEVELOPMENT || DEBUG
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_vm_pressure_task_footprint_min, CTLFLAG_RW | CTLFLAG_LOCKED, &vm_pressure_task_footprint_min, 0, "");
+#endif /* DEVELOPMENT || DEBUG */
 
 #endif /* VM_PRESSURE_EVENTS */
 
+
+#if DEVELOPMENT || DEBUG
+
+lck_grp_attr_t *disconnect_page_mappings_lck_grp_attr;
+lck_grp_t *disconnect_page_mappings_lck_grp;
+static lck_mtx_t disconnect_page_mappings_mutex;
+
+extern boolean_t kill_on_no_paging_space;
+#endif /* DEVELOPMENT || DEBUG */
+
+
+/*
+ * Table that expresses the probability of a process
+ * being used in the next hour.
+ */
+typedef struct memorystatus_internal_probabilities {
+       char proc_name[MAXCOMLEN + 1];
+       int use_probability;
+} memorystatus_internal_probabilities_t;
+
+static memorystatus_internal_probabilities_t *memorystatus_global_probabilities_table = NULL;
+static size_t memorystatus_global_probabilities_size = 0;
+
 /* Freeze */
 
 #if CONFIG_FREEZE
-
 boolean_t memorystatus_freeze_enabled = FALSE;
 int memorystatus_freeze_wakeup = 0;
+int memorystatus_freeze_jetsam_band = 0; /* the jetsam band which will contain P_MEMSTAT_FROZEN processes */
 
 lck_grp_attr_t *freezer_lck_grp_attr;
 lck_grp_t *freezer_lck_grp;
@@ -426,8 +785,11 @@ static lck_mtx_t freezer_mutex;
 
 static inline boolean_t memorystatus_can_freeze_processes(void);
 static boolean_t memorystatus_can_freeze(boolean_t *memorystatus_freeze_swap_low);
-
+static boolean_t memorystatus_is_process_eligible_for_freeze(proc_t p);
 static void memorystatus_freeze_thread(void *param __unused, wait_result_t wr __unused);
+static boolean_t memorystatus_freeze_thread_should_run(void);
+
+void memorystatus_disable_freeze(void);
 
 /* Thresholds */
 static unsigned int memorystatus_freeze_threshold = 0;
@@ -438,24 +800,37 @@ static unsigned int memorystatus_freeze_pages_max = 0;
 static unsigned int memorystatus_freeze_suspended_threshold = FREEZE_SUSPENDED_THRESHOLD_DEFAULT;
 
 static unsigned int memorystatus_freeze_daily_mb_max = FREEZE_DAILY_MB_MAX_DEFAULT;
+static uint64_t  memorystatus_freeze_budget_pages_remaining = 0; //remaining # of pages that can be frozen to disk
+static boolean_t memorystatus_freeze_degradation = FALSE; //protected by the freezer mutex. Signals we are in a degraded freeze mode.
+
+static unsigned int memorystatus_max_frozen_demotions_daily = 0;
+static unsigned int memorystatus_thaw_count_demotion_threshold = 0;
 
 /* Stats */
-static uint64_t memorystatus_freeze_count = 0;
 static uint64_t memorystatus_freeze_pageouts = 0;
 
 /* Throttling */
+#define DEGRADED_WINDOW_MINS    (30)
+#define NORMAL_WINDOW_MINS      (24 * 60)
+
 static throttle_interval_t throttle_intervals[] = {
-       {      60,  8, 0, 0, { 0, 0 }, FALSE }, /* 1 hour intermediate interval, 8x burst */
-       { 24 * 60,  1, 0, 0, { 0, 0 }, FALSE }, /* 24 hour long interval, no burst */
+       { DEGRADED_WINDOW_MINS, 1, 0, 0, { 0, 0 }},
+       { NORMAL_WINDOW_MINS, 1, 0, 0, { 0, 0 }},
 };
+throttle_interval_t *degraded_throttle_window = &throttle_intervals[0];
+throttle_interval_t *normal_throttle_window = &throttle_intervals[1];
 
-static uint64_t memorystatus_freeze_throttle_count = 0;
+extern uint64_t vm_swap_get_free_space(void);
+extern boolean_t vm_swap_max_budget(uint64_t *);
 
-static unsigned int memorystatus_suspended_footprint_total = 0;
+static void memorystatus_freeze_update_throttle(uint64_t *budget_pages_allowed);
 
-extern uint64_t vm_swap_get_free_space(void);
+static uint64_t memorystatus_freezer_thread_next_run_ts = 0;
 
-static boolean_t memorystatus_freeze_update_throttle();
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_count, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_frozen_count, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_thaw_count, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_thaw_count, 0, "");
+SYSCTL_QUAD(_kern, OID_AUTO, memorystatus_freeze_pageouts, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_freeze_pageouts, "");
+SYSCTL_QUAD(_kern, OID_AUTO, memorystatus_freeze_budget_pages_remaining, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_freeze_budget_pages_remaining, "");
 
 #endif /* CONFIG_FREEZE */
 
@@ -465,69 +840,78 @@ extern struct knote *vm_find_knote_from_pid(pid_t, struct klist *);
 
 #if DEVELOPMENT || DEBUG
 
-#if CONFIG_JETSAM
+static unsigned int memorystatus_debug_dump_this_bucket = 0;
 
 static void
-memorystatus_debug_dump_bucket_locked (unsigned int bucket_index)
+memorystatus_debug_dump_bucket_locked(unsigned int bucket_index)
 {
        proc_t p = NULL;
-       uint32_t pages = 0;
-       uint32_t pages_in_mb = 0;
+       uint64_t bytes = 0;
+       int ledger_limit = 0;
        unsigned int b = bucket_index;
        boolean_t traverse_all_buckets = FALSE;
 
-        if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
+       if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
                traverse_all_buckets = TRUE;
                b = 0;
-        } else {
+       } else {
                traverse_all_buckets = FALSE;
                b = bucket_index;
        }
 
        /*
-        * Missing from this dump is the value actually
-        * stored in the ledger... also, format could be better.
+        * footprint reported in [pages / MB ]
+        * limits reported as:
+        *      L-limit  proc's Ledger limit
+        *      C-limit  proc's Cached limit, should match Ledger
+        *      A-limit  proc's Active limit
+        *     IA-limit  proc's Inactive limit
+        *      F==Fatal,  NF==NonFatal
         */
-        printf("memorystatus_debug_dump ***START***\n");
-       printf("bucket [pid] [pages/pages-mb] state [EP / RP] dirty deadline [C-limit / A-limit / IA-limit] name\n");
+
+       printf("memorystatus_debug_dump ***START*(PAGE_SIZE_64=%llu)**\n", PAGE_SIZE_64);
+       printf("bucket [pid]       [pages / MB]     [state]      [EP / RP]   dirty     deadline [L-limit / C-limit / A-limit / IA-limit] name\n");
        p = memorystatus_get_first_proc_locked(&b, traverse_all_buckets);
        while (p) {
-               memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL, NULL);
-               pages_in_mb = (pages * 4096) /1024 / 1024;
-                printf("%d     [%d]     [%d/%dMB] 0x%x [%d / %d] 0x%x %lld    [%d%s / %d%s / %d%s] %s\n", 
-                      b, p->p_pid, pages, pages_in_mb,
-                      p->p_memstat_state, p->p_memstat_effectivepriority, p->p_memstat_requestedpriority, p->p_memstat_dirty, p->p_memstat_idledeadline,
-                      p->p_memstat_memlimit,
-                      (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"),
-                      p->p_memstat_memlimit_active, 
-                      (p->p_memstat_state & P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL ? "F " : "NF"),
-                      p->p_memstat_memlimit_inactive, 
-                      (p->p_memstat_state & P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL ? "F " : "NF"),
-                      (p->p_comm ? p->p_comm : "unknown"));
+               bytes = get_task_phys_footprint(p->task);
+               task_get_phys_footprint_limit(p->task, &ledger_limit);
+               printf("%2d     [%5d]     [%5lld /%3lldMB]   0x%-8x   [%2d / %2d]   0x%-3x   %10lld    [%3d / %3d%s / %3d%s / %3d%s]   %s\n",
+                   b, p->p_pid,
+                   (bytes / PAGE_SIZE_64),             /* task's footprint converted from bytes to pages     */
+                   (bytes / (1024ULL * 1024ULL)),      /* task's footprint converted from bytes to MB */
+                   p->p_memstat_state, p->p_memstat_effectivepriority, p->p_memstat_requestedpriority, p->p_memstat_dirty, p->p_memstat_idledeadline,
+                   ledger_limit,
+                   p->p_memstat_memlimit,
+                   (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"),
+                   p->p_memstat_memlimit_active,
+                   (p->p_memstat_state & P_MEMSTAT_MEMLIMIT_ACTIVE_FATAL ? "F " : "NF"),
+                   p->p_memstat_memlimit_inactive,
+                   (p->p_memstat_state & P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL ? "F " : "NF"),
+                   (*p->p_name ? p->p_name : "unknown"));
                p = memorystatus_get_next_proc_locked(&b, p, traverse_all_buckets);
-        }
-        printf("memorystatus_debug_dump ***END***\n");
+       }
+       printf("memorystatus_debug_dump ***END***\n");
 }
 
 static int
 sysctl_memorystatus_debug_dump_bucket SYSCTL_HANDLER_ARGS
 {
 #pragma unused(oidp, arg2)
-        int bucket_index = 0;
-        int error;
+       int bucket_index = 0;
+       int error;
        error = SYSCTL_OUT(req, arg1, sizeof(int));
        if (error || !req->newptr) {
-               return (error);
+               return error;
+       }
+       error = SYSCTL_IN(req, &bucket_index, sizeof(int));
+       if (error || !req->newptr) {
+               return error;
        }
-        error = SYSCTL_IN(req, &bucket_index, sizeof(int));
-        if (error || !req->newptr) {
-                return (error);
-        }
        if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
                /*
                 * All jetsam buckets will be dumped.
                 */
-        } else {
+       } else {
                /*
                 * Only a single bucket will be dumped.
                 */
@@ -537,17 +921,17 @@ sysctl_memorystatus_debug_dump_bucket SYSCTL_HANDLER_ARGS
        memorystatus_debug_dump_bucket_locked(bucket_index);
        proc_list_unlock();
        memorystatus_debug_dump_this_bucket = bucket_index;
-       return (error);
+       return error;
 }
 
 /*
  * Debug aid to look at jetsam buckets and proc jetsam fields.
  *     Use this sysctl to act on a particular jetsam bucket.
  *     Writing the sysctl triggers the dump.
- *     Usage: sysctl kern.memorystatus_debug_dump_this_bucket=<bucket_index>
+ *      Usage: sysctl kern.memorystatus_debug_dump_this_bucket=<bucket_index>
  */
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_debug_dump_this_bucket, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_debug_dump_this_bucket, 0, sysctl_memorystatus_debug_dump_bucket, "I", "");
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_debug_dump_this_bucket, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_debug_dump_this_bucket, 0, sysctl_memorystatus_debug_dump_bucket, "I", "");
 
 
 /* Debug aid to aid determination of limit */
@@ -559,15 +943,17 @@ sysctl_memorystatus_highwater_enable SYSCTL_HANDLER_ARGS
        proc_t p;
        unsigned int b = 0;
        int error, enable = 0;
+       boolean_t use_active;   /* use the active limit and active limit attributes */
+       boolean_t is_fatal;
 
        error = SYSCTL_OUT(req, arg1, sizeof(int));
        if (error || !req->newptr) {
-               return (error);
+               return error;
        }
 
        error = SYSCTL_IN(req, &enable, sizeof(int));
        if (error || !req->newptr) {
-               return (error);
+               return error;
        }
 
        if (!(enable == 0 || enable == 1)) {
@@ -578,20 +964,14 @@ sysctl_memorystatus_highwater_enable SYSCTL_HANDLER_ARGS
 
        p = memorystatus_get_first_proc_locked(&b, TRUE);
        while (p) {
-               boolean_t trigger_exception;
+               use_active = proc_jetsam_state_is_active_locked(p);
 
                if (enable) {
-                       /*
-                        * No need to consider P_MEMSTAT_MEMLIMIT_BACKGROUND anymore.
-                        * Background limits are described via the inactive limit slots.
-                        */
-
-                       if (proc_jetsam_state_is_active_locked(p) == TRUE) {
-                               CACHE_ACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                       if (use_active == TRUE) {
+                               CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal);
                        } else {
-                               CACHE_INACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                               CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal);
                        }
-
                } else {
                        /*
                         * Disabling limits does not touch the stored variants.
@@ -599,38 +979,140 @@ sysctl_memorystatus_highwater_enable SYSCTL_HANDLER_ARGS
                         */
                        p->p_memstat_memlimit = -1;
                        p->p_memstat_state |= P_MEMSTAT_FATAL_MEMLIMIT;
-                       trigger_exception = TRUE;
+                       is_fatal = TRUE;
                }
 
                /*
                 * Enforce the cached limit by writing to the ledger.
                 */
-               task_set_phys_footprint_limit_internal(p->task, (p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit: -1, NULL, trigger_exception);
+               task_set_phys_footprint_limit_internal(p->task, (p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit: -1, NULL, use_active, is_fatal);
 
                p = memorystatus_get_next_proc_locked(&b, p, TRUE);
        }
-       
+
        memorystatus_highwater_enabled = enable;
 
        proc_list_unlock();
 
        return 0;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_highwater_enabled, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_highwater_enabled, 0, sysctl_memorystatus_highwater_enable, "I", "");
+
+#if VM_PRESSURE_EVENTS
+
+/*
+ * This routine is used for targeted notifications regardless of system memory pressure
+ * and regardless of whether or not the process has already been notified.
+ * It bypasses and has no effect on the only-one-notification per soft-limit policy.
+ *
+ * "memnote" is the current user.
+ */
+
+static int
+sysctl_memorystatus_vm_pressure_send SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+
+       int error = 0, pid = 0;
+       struct knote *kn = NULL;
+       boolean_t found_knote = FALSE;
+       int fflags = 0;         /* filter flags for EVFILT_MEMORYSTATUS */
+       uint64_t value = 0;
+
+       error = sysctl_handle_quad(oidp, &value, 0, req);
+       if (error || !req->newptr) {
+               return error;
+       }
+
+       /*
+        * Find the pid in the low 32 bits of value passed in.
+        */
+       pid = (int)(value & 0xFFFFFFFF);
+
+       /*
+        * Find notification in the high 32 bits of the value passed in.
+        */
+       fflags = (int)((value >> 32) & 0xFFFFFFFF);
+
+       /*
+        * For backwards compatibility, when no notification is
+        * passed in, default to the NOTE_MEMORYSTATUS_PRESSURE_WARN
+        */
+       if (fflags == 0) {
+               fflags = NOTE_MEMORYSTATUS_PRESSURE_WARN;
+               // printf("memorystatus_vm_pressure_send: using default notification [0x%x]\n", fflags);
+       }
+
+       /*
+        * See event.h ... fflags for EVFILT_MEMORYSTATUS
+        */
+       if (!((fflags == NOTE_MEMORYSTATUS_PRESSURE_NORMAL) ||
+           (fflags == NOTE_MEMORYSTATUS_PRESSURE_WARN) ||
+           (fflags == NOTE_MEMORYSTATUS_PRESSURE_CRITICAL) ||
+           (fflags == NOTE_MEMORYSTATUS_LOW_SWAP) ||
+           (fflags == NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) ||
+           (fflags == NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) ||
+           (((fflags & NOTE_MEMORYSTATUS_MSL_STATUS) != 0 &&
+           ((fflags & ~NOTE_MEMORYSTATUS_MSL_STATUS) == 0))))) {
+               printf("memorystatus_vm_pressure_send: notification [0x%x] not supported \n", fflags);
+               error = 1;
+               return error;
+       }
+
+       /*
+        * Forcibly send pid a memorystatus notification.
+        */
+
+       memorystatus_klist_lock();
+
+       SLIST_FOREACH(kn, &memorystatus_klist, kn_selnext) {
+               proc_t knote_proc = knote_get_kq(kn)->kq_p;
+               pid_t knote_pid = knote_proc->p_pid;
+
+               if (knote_pid == pid) {
+                       /*
+                        * Forcibly send this pid a memorystatus notification.
+                        */
+                       kn->kn_fflags = fflags;
+                       found_knote = TRUE;
+               }
+       }
+
+       if (found_knote) {
+               KNOTE(&memorystatus_klist, 0);
+               printf("memorystatus_vm_pressure_send: (value 0x%llx) notification [0x%x] sent to process [%d] \n", value, fflags, pid);
+               error = 0;
+       } else {
+               printf("memorystatus_vm_pressure_send: (value 0x%llx) notification [0x%x] not sent to process [%d] (none registered?)\n", value, fflags, pid);
+               error = 1;
+       }
+
+       memorystatus_klist_unlock();
 
+       return error;
 }
 
-SYSCTL_INT(_kern, OID_AUTO, memorystatus_idle_snapshot, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_idle_snapshot, 0, "");
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_send, CTLTYPE_QUAD | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+    0, 0, &sysctl_memorystatus_vm_pressure_send, "Q", "");
+
+#endif /* VM_PRESSURE_EVENTS */
+
+SYSCTL_INT(_kern, OID_AUTO, memorystatus_idle_snapshot, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_idle_snapshot, 0, "");
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_highwater_enabled, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_highwater_enabled, 0, sysctl_memorystatus_highwater_enable, "I", "");
+#if CONFIG_JETSAM
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_critical, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_available_pages_critical, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_critical_base, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_available_pages_critical_base, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_critical_idle_offset, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_available_pages_critical_idle_offset, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_policy_more_free_offset_pages, CTLFLAG_RW, &memorystatus_policy_more_free_offset_pages, 0, "");
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages, CTLFLAG_RD|CTLFLAG_LOCKED, &memorystatus_available_pages, 0, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_critical, CTLFLAG_RD|CTLFLAG_LOCKED, &memorystatus_available_pages_critical, 0, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_critical_base, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_available_pages_critical_base, 0, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_critical_idle_offset, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_available_pages_critical_idle_offset, 0, "");
+static unsigned int memorystatus_jetsam_panic_debug = 0;
+static unsigned int memorystatus_jetsam_policy_offset_pages_diagnostic = 0;
 
 /* Diagnostic code */
 
 enum {
-       kJetsamDiagnosticModeNone =              0, 
+       kJetsamDiagnosticModeNone =              0,
        kJetsamDiagnosticModeAll  =              1,
        kJetsamDiagnosticModeStopAtFirstActive = 2,
        kJetsamDiagnosticModeCount
@@ -646,27 +1128,28 @@ sysctl_jetsam_diagnostic_mode SYSCTL_HANDLER_ARGS
        const char *diagnosticStrings[] = {
                "jetsam: diagnostic mode: resetting critical level.",
                "jetsam: diagnostic mode: will examine all processes",
-               "jetsam: diagnostic mode: will stop at first active process"                
+               "jetsam: diagnostic mode: will stop at first active process"
        };
-        
+
        int error, val = jetsam_diagnostic_mode;
        boolean_t changed = FALSE;
 
        error = sysctl_handle_int(oidp, &val, 0, req);
-       if (error || !req->newptr)
-               return (error);
+       if (error || !req->newptr) {
+               return error;
+       }
        if ((val < 0) || (val >= kJetsamDiagnosticModeCount)) {
                printf("jetsam: diagnostic mode: invalid value - %d\n", val);
                return EINVAL;
        }
-       
+
        proc_list_lock();
-       
+
        if ((unsigned int) val != jetsam_diagnostic_mode) {
                jetsam_diagnostic_mode = val;
 
                memorystatus_jetsam_policy &= ~kPolicyDiagnoseActive;
-                
+
                switch (jetsam_diagnostic_mode) {
                case kJetsamDiagnosticModeNone:
                        /* Already cleared */
@@ -681,114 +1164,82 @@ sysctl_jetsam_diagnostic_mode SYSCTL_HANDLER_ARGS
                        /* Already validated */
                        break;
                }
-               
+
                memorystatus_update_levels_locked(FALSE);
                changed = TRUE;
        }
-        
+
        proc_list_unlock();
-       
+
        if (changed) {
                printf("%s\n", diagnosticStrings[val]);
        }
-       
-       return (0);
+
+       return 0;
 }
 
-SYSCTL_PROC(_debug, OID_AUTO, jetsam_diagnostic_mode, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_LOCKED|CTLFLAG_ANYBODY,
-               &jetsam_diagnostic_mode, 0, sysctl_jetsam_diagnostic_mode, "I", "Jetsam Diagnostic Mode");
+SYSCTL_PROC(_debug, OID_AUTO, jetsam_diagnostic_mode, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY,
+    &jetsam_diagnostic_mode, 0, sysctl_jetsam_diagnostic_mode, "I", "Jetsam Diagnostic Mode");
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jetsam_policy_offset_pages_diagnostic, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_jetsam_policy_offset_pages_diagnostic, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_jetsam_policy_offset_pages_diagnostic, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_jetsam_policy_offset_pages_diagnostic, 0, "");
 
 #if VM_PRESSURE_EVENTS
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_pressure, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_available_pages_pressure, 0, "");
-
-
-/*
- * This routine is used for targeted notifications
- * regardless of system memory pressure.
- * "memnote" is the current user.
- */
-
-static int
-sysctl_memorystatus_vm_pressure_send SYSCTL_HANDLER_ARGS
-{
-#pragma unused(arg1, arg2)
-
-       int error = 0, pid = 0;
-       int ret = 0;
-       struct knote *kn = NULL;
-       boolean_t found_knote = FALSE;
-
-       error = sysctl_handle_int(oidp, &pid, 0, req);
-       if (error || !req->newptr)
-               return (error);
-
-       /*
-        * We inspect 3 lists here for targeted notifications:
-        * - memorystatus_klist
-        * - vm_pressure_klist
-        * - vm_pressure_dormant_klist
-        *
-        * The vm_pressure_* lists are tied to the old VM_PRESSURE
-        * notification mechanism. We intend to stop using that
-        * mechanism and, in turn, get rid of the 2 lists and
-        * vm_dispatch_pressure_note_to_pid() too.
-        */
-
-       memorystatus_klist_lock();
-
-       SLIST_FOREACH(kn, &memorystatus_klist, kn_selnext) {
-               proc_t knote_proc = kn->kn_kq->kq_p;
-               pid_t knote_pid = knote_proc->p_pid;
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_available_pages_pressure, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_available_pages_pressure, 0, "");
 
-               if (knote_pid == pid) {
-                       /*
-                        * Forcibly send this pid a "warning" memory pressure notification.
-                        */
-                       kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_WARN;
-                       found_knote = TRUE;
-               }
-       }
+#endif /* VM_PRESSURE_EVENTS */
 
-       if (found_knote) {
-               KNOTE(&memorystatus_klist, 0);
-               ret = 0;
-       } else {
-               ret = vm_dispatch_pressure_note_to_pid(pid, FALSE);
-       }
+#endif /* CONFIG_JETSAM */
 
-       memorystatus_klist_unlock();
+#if CONFIG_FREEZE
 
-       return ret;
-}
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_jetsam_band, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_jetsam_band, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_daily_mb_max, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_daily_mb_max, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_degraded_mode, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_freeze_degradation, 0, "");
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_send, CTLTYPE_INT|CTLFLAG_WR|CTLFLAG_LOCKED|CTLFLAG_MASKED,
-    0, 0, &sysctl_memorystatus_vm_pressure_send, "I", "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_threshold, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_threshold, 0, "");
 
-#endif /* VM_PRESSURE_EVENTS */
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_pages_min, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_pages_min, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_pages_max, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_pages_max, 0, "");
 
-#endif /* CONFIG_JETSAM */
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_refreeze_eligible_count, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_refreeze_eligible_count, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_processes_max, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_frozen_processes_max, 0, "");
 
-#if CONFIG_FREEZE
+/*
+ * Max. shared-anonymous memory in MB that can be held by frozen processes in the high jetsam band.
+ * "0" means no limit.
+ * Default is 10% of system-wide task limit.
+ */
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_daily_mb_max, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_freeze_daily_mb_max, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_shared_mb_max, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_frozen_shared_mb_max, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_shared_mb, CTLFLAG_RD | CTLFLAG_LOCKED, &memorystatus_frozen_shared_mb, 0, "");
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_threshold, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_freeze_threshold, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_shared_mb_per_process_max, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_shared_mb_per_process_max, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_private_shared_pages_ratio, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_private_shared_pages_ratio, 0, "");
 
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_pages_min, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_freeze_pages_min, 0, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_pages_max, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_freeze_pages_max, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_min_processes, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_suspended_threshold, 0, "");
 
-SYSCTL_QUAD(_kern, OID_AUTO, memorystatus_freeze_count, CTLFLAG_RD|CTLFLAG_LOCKED, &memorystatus_freeze_count, "");
-SYSCTL_QUAD(_kern, OID_AUTO, memorystatus_freeze_pageouts, CTLFLAG_RD|CTLFLAG_LOCKED, &memorystatus_freeze_pageouts, "");
-SYSCTL_QUAD(_kern, OID_AUTO, memorystatus_freeze_throttle_count, CTLFLAG_RD|CTLFLAG_LOCKED, &memorystatus_freeze_throttle_count, "");
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_min_processes, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_freeze_suspended_threshold, 0, "");
+/*
+ * max. # of frozen process demotions we will allow in our daily cycle.
+ */
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_max_freeze_demotions_daily, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_max_frozen_demotions_daily, 0, "");
+/*
+ * min # of thaws needed by a process to protect it from getting demoted into the IDLE band.
+ */
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_thaw_count_demotion_threshold, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_thaw_count_demotion_threshold, 0, "");
 
 boolean_t memorystatus_freeze_throttle_enabled = TRUE;
-SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_throttle_enabled, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_freeze_throttle_enabled, 0, "");
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_throttle_enabled, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_throttle_enabled, 0, "");
+
+/*
+ * When set to true, this keeps frozen processes in the compressor pool in memory, instead of swapping them out to disk.
+ * Exposed via the sysctl kern.memorystatus_freeze_to_memory.
+ */
+boolean_t memorystatus_freeze_to_memory = FALSE;
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_freeze_to_memory, CTLFLAG_RW | CTLFLAG_LOCKED, &memorystatus_freeze_to_memory, 0, "");
 
-/* 
+#define VM_PAGES_FOR_ALL_PROCS  (2)
+/*
  * Manual trigger of freeze and thaw for dev / debug kernels only.
  */
 static int
@@ -797,16 +1248,19 @@ sysctl_memorystatus_freeze SYSCTL_HANDLER_ARGS
 #pragma unused(arg1, arg2)
        int error, pid = 0;
        proc_t p;
+       int freezer_error_code = 0;
 
        if (memorystatus_freeze_enabled == FALSE) {
+               printf("sysctl_freeze: Freeze is DISABLED\n");
                return ENOTSUP;
        }
 
        error = sysctl_handle_int(oidp, &pid, 0, req);
-       if (error || !req->newptr)
-               return (error);
+       if (error || !req->newptr) {
+               return error;
+       }
 
-       if (pid == 2) {
+       if (pid == VM_PAGES_FOR_ALL_PROCS) {
                vm_pageout_anonymous_pages();
 
                return 0;
@@ -816,51 +1270,120 @@ sysctl_memorystatus_freeze SYSCTL_HANDLER_ARGS
 
        p = proc_find(pid);
        if (p != NULL) {
-               uint32_t purgeable, wired, clean, dirty;
-               boolean_t shared;
-               uint32_t max_pages = 0;
+               uint32_t purgeable, wired, clean, dirty, shared;
+               uint32_t max_pages = 0, state = 0;
 
-               if (DEFAULT_FREEZER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPBACKED) {
+               if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                       /*
+                        * Freezer backed by the compressor and swap file(s)
+                        * will hold compressed data.
+                        *
+                        * Set the sysctl kern.memorystatus_freeze_to_memory to true to keep compressed data from
+                        * being swapped out to disk. Note that this disables freezer swap support globally,
+                        * not just for the process being frozen.
+                        *
+                        *
+                        * We don't care about the global freezer budget or the process's (min/max) budget here.
+                        * The freeze sysctl is meant to force-freeze a process.
+                        *
+                        * We also don't update any global or process stats on this path, so that the jetsam/ freeze
+                        * logic remains unaffected. The tasks we're performing here are: freeze the process, set the
+                        * P_MEMSTAT_FROZEN bit, and elevate the process to a higher band (if the freezer is active).
+                        */
+                       max_pages = memorystatus_freeze_pages_max;
+               } else {
+                       /*
+                        * We only have the compressor without any swap.
+                        */
+                       max_pages = UINT32_MAX - 1;
+               }
 
-                       unsigned int avail_swap_space = 0; /* in pages. */
+               proc_list_lock();
+               state = p->p_memstat_state;
+               proc_list_unlock();
 
-                       if (DEFAULT_FREEZER_IS_ACTIVE) {
-                               /*
-                                * Freezer backed by default pager and swap file(s).
-                                */
-                               avail_swap_space = default_pager_swap_pages_free();
-                       } else {
-                               /*
-                                * Freezer backed by the compressor and swap file(s)
-                                * while will hold compressed data.
-                                */
-                               avail_swap_space = vm_swap_get_free_space() / PAGE_SIZE_64;
+               /*
+                * The jetsam path also verifies that the process is a suspended App. We don't care about that here.
+                * We simply ensure that jetsam is not already working on the process and that the process has not
+                * explicitly disabled freezing.
+                */
+               if (state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_FREEZE_DISABLED)) {
+                       printf("sysctl_freeze: p_memstat_state check failed, process is%s%s%s\n",
+                           (state & P_MEMSTAT_TERMINATED) ? " terminated" : "",
+                           (state & P_MEMSTAT_LOCKED) ? " locked" : "",
+                           (state & P_MEMSTAT_FREEZE_DISABLED) ? " unfreezable" : "");
+
+                       proc_rele(p);
+                       lck_mtx_unlock(&freezer_mutex);
+                       return EPERM;
+               }
+
+               error = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, &freezer_error_code, FALSE /* eval only */);
+
+               if (error) {
+                       char reason[128];
+                       if (freezer_error_code == FREEZER_ERROR_EXCESS_SHARED_MEMORY) {
+                               strlcpy(reason, "too much shared memory", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_LOW_PRIVATE_SHARED_RATIO) {
+                               strlcpy(reason, "low private-shared pages ratio", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_NO_COMPRESSOR_SPACE) {
+                               strlcpy(reason, "no compressor space", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_NO_SWAP_SPACE) {
+                               strlcpy(reason, "no swap space", 128);
                        }
 
-                       max_pages = MIN(avail_swap_space, memorystatus_freeze_pages_max);
+                       printf("sysctl_freeze: task_freeze failed: %s\n", reason);
 
+                       if (error == KERN_NO_SPACE) {
+                               /* Make it easy to distinguish between failures due to low compressor/ swap space and other failures. */
+                               error = ENOSPC;
+                       } else {
+                               error = EIO;
+                       }
                } else {
-                       /*
-                        * We only have the compressor without any swap.
-                        */
-                       max_pages = UINT32_MAX - 1;
+                       proc_list_lock();
+                       if ((p->p_memstat_state & P_MEMSTAT_FROZEN) == 0) {
+                               p->p_memstat_state |= P_MEMSTAT_FROZEN;
+                               memorystatus_frozen_count++;
+                       }
+                       p->p_memstat_frozen_count++;
+
+
+                       proc_list_unlock();
+
+                       if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                               /*
+                                * We elevate only if we are going to swap out the data.
+                                */
+                               error = memorystatus_update_inactive_jetsam_priority_band(pid, MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_ENABLE,
+                                   memorystatus_freeze_jetsam_band, TRUE);
+
+                               if (error) {
+                                       printf("sysctl_freeze: Elevating frozen process to higher jetsam band failed with %d\n", error);
+                               }
+                       }
                }
 
-               error = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, FALSE);
                proc_rele(p);
 
-               if (error)
-                       error = EIO;
-
                lck_mtx_unlock(&freezer_mutex);
                return error;
+       } else {
+               printf("sysctl_freeze: Invalid process\n");
        }
 
+
        lck_mtx_unlock(&freezer_mutex);
        return EINVAL;
 }
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_freeze, CTLTYPE_INT|CTLFLAG_WR|CTLFLAG_LOCKED|CTLFLAG_MASKED,
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_freeze, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
     0, 0, &sysctl_memorystatus_freeze, "I", "");
 
 static int
@@ -876,78 +1399,331 @@ sysctl_memorystatus_available_pages_thaw SYSCTL_HANDLER_ARGS
        }
 
        error = sysctl_handle_int(oidp, &pid, 0, req);
-       if (error || !req->newptr)
-               return (error);
-
-       p = proc_find(pid);
-       if (p != NULL) {
-               error = task_thaw(p->task);
-               proc_rele(p);
-               
-               if (error)
-                       error = EIO;
+       if (error || !req->newptr) {
                return error;
        }
 
+       if (pid == VM_PAGES_FOR_ALL_PROCS) {
+               do_fastwake_warmup_all();
+               return 0;
+       } else {
+               p = proc_find(pid);
+               if (p != NULL) {
+                       error = task_thaw(p->task);
+
+                       if (error) {
+                               error = EIO;
+                       } else {
+                               /*
+                                * task_thaw() succeeded.
+                                *
+                                * We increment memorystatus_frozen_count on the sysctl freeze path.
+                                * And so we need the P_MEMSTAT_FROZEN to decrement the frozen count
+                                * when this process exits.
+                                *
+                                * proc_list_lock();
+                                * p->p_memstat_state &= ~P_MEMSTAT_FROZEN;
+                                * proc_list_unlock();
+                                */
+                       }
+                       proc_rele(p);
+                       return error;
+               }
+       }
+
        return EINVAL;
 }
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_thaw, CTLTYPE_INT|CTLFLAG_WR|CTLFLAG_LOCKED|CTLFLAG_MASKED,
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_thaw, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
     0, 0, &sysctl_memorystatus_available_pages_thaw, "I", "");
 
-#endif /* CONFIG_FREEZE */
-
-#endif /* DEVELOPMENT || DEBUG */
-
-extern kern_return_t kernel_thread_start_priority(thread_continue_t continuation,
-                                                  void *parameter,
-                                                  integer_t priority,
-                                                  thread_t *new_thread);
+typedef struct _global_freezable_status {
+       boolean_t       freeze_pages_threshold_crossed;
+       boolean_t       freeze_eligible_procs_available;
+       boolean_t       freeze_scheduled_in_future;
+}global_freezable_status_t;
+
+typedef struct _proc_freezable_status {
+       boolean_t       freeze_has_memstat_state;
+       boolean_t       freeze_has_pages_min;
+       int             freeze_has_probability;
+       boolean_t       freeze_attempted;
+       uint32_t        p_memstat_state;
+       uint32_t        p_pages;
+       int             p_freeze_error_code;
+       int             p_pid;
+       char            p_name[MAXCOMLEN + 1];
+}proc_freezable_status_t;
+
+#define MAX_FREEZABLE_PROCESSES 100
 
-#if CONFIG_JETSAM
-/*
- * Picks the sorting routine for a given jetsam priority band.
- *
- * Input:
- *     bucket_index - jetsam priority band to be sorted.
- *     sort_order - JETSAM_SORT_xxx from kern_memorystatus.h
- *             Currently sort_order is only meaningful when handling
- *             coalitions.
- *
- * Return: 
- *     0     on success
- *     non-0 on failure
- */
-static int memorystatus_sort_bucket(unsigned int bucket_index, int sort_order)
+static int
+memorystatus_freezer_get_status(user_addr_t buffer, size_t buffer_size, int32_t *retval)
 {
-       int coal_sort_order;
+       uint32_t                        proc_count = 0, i = 0;
+       global_freezable_status_t       *list_head;
+       proc_freezable_status_t         *list_entry;
+       size_t                          list_size = 0;
+       proc_t                          p;
+       memstat_bucket_t                *bucket;
+       uint32_t                        state = 0, pages = 0, entry_count = 0;
+       boolean_t                       try_freeze = TRUE;
+       int                             error = 0, probability_of_use = 0;
+
+
+       if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE == FALSE) {
+               return ENOTSUP;
+       }
 
-       /*
-        * Verify the jetsam priority
-        */
-        if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
-               return(EINVAL);
-        }
+       list_size = sizeof(global_freezable_status_t) + (sizeof(proc_freezable_status_t) * MAX_FREEZABLE_PROCESSES);
 
-#if DEVELOPMENT || DEBUG
-        if (sort_order == JETSAM_SORT_DEFAULT) {
-               coal_sort_order = COALITION_SORT_DEFAULT;
-       } else {
-               coal_sort_order = sort_order;           /* only used for testing scenarios */
+       if (buffer_size < list_size) {
+               return EINVAL;
        }
-#else
-       /* Verify default */
-        if (sort_order == JETSAM_SORT_DEFAULT) {
-               coal_sort_order = COALITION_SORT_DEFAULT;
-       } else {
-               return(EINVAL);
+
+       list_head = (global_freezable_status_t*)kalloc(list_size);
+       if (list_head == NULL) {
+               return ENOMEM;
        }
-#endif
+
+       memset(list_head, 0, list_size);
+
+       list_size = sizeof(global_freezable_status_t);
 
        proc_list_lock();
-       switch (bucket_index) {
-       case JETSAM_PRIORITY_FOREGROUND:
-               if (memorystatus_sort_by_largest_coalition_locked(bucket_index, coal_sort_order) == 0) {
+
+       uint64_t curr_time = mach_absolute_time();
+
+       list_head->freeze_pages_threshold_crossed = (memorystatus_available_pages < memorystatus_freeze_threshold);
+       list_head->freeze_eligible_procs_available = ((memorystatus_suspended_count - memorystatus_frozen_count) > memorystatus_freeze_suspended_threshold);
+       list_head->freeze_scheduled_in_future = (curr_time < memorystatus_freezer_thread_next_run_ts);
+
+       list_entry = (proc_freezable_status_t*) ((uintptr_t)list_head + sizeof(global_freezable_status_t));
+
+       bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
+
+       entry_count = (memorystatus_global_probabilities_size / sizeof(memorystatus_internal_probabilities_t));
+
+       p = memorystatus_get_first_proc_locked(&i, FALSE);
+       proc_count++;
+
+       while ((proc_count <= MAX_FREEZABLE_PROCESSES) &&
+           (p) &&
+           (list_size < buffer_size)) {
+               if (isApp(p) == FALSE) {
+                       p = memorystatus_get_next_proc_locked(&i, p, FALSE);
+                       proc_count++;
+                       continue;
+               }
+
+               strlcpy(list_entry->p_name, p->p_name, MAXCOMLEN + 1);
+
+               list_entry->p_pid = p->p_pid;
+
+               state = p->p_memstat_state;
+
+               if ((state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_FREEZE_DISABLED | P_MEMSTAT_FREEZE_IGNORE)) ||
+                   !(state & P_MEMSTAT_SUSPENDED)) {
+                       try_freeze = list_entry->freeze_has_memstat_state = FALSE;
+               } else {
+                       try_freeze = list_entry->freeze_has_memstat_state = TRUE;
+               }
+
+               list_entry->p_memstat_state = state;
+
+               memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL);
+               if (pages < memorystatus_freeze_pages_min) {
+                       try_freeze = list_entry->freeze_has_pages_min = FALSE;
+               } else {
+                       list_entry->freeze_has_pages_min = TRUE;
+                       if (try_freeze != FALSE) {
+                               try_freeze = TRUE;
+                       }
+               }
+
+               list_entry->p_pages = pages;
+
+               if (entry_count) {
+                       uint32_t j = 0;
+                       for (j = 0; j < entry_count; j++) {
+                               if (strncmp(memorystatus_global_probabilities_table[j].proc_name,
+                                   p->p_name,
+                                   MAXCOMLEN + 1) == 0) {
+                                       probability_of_use = memorystatus_global_probabilities_table[j].use_probability;
+                                       break;
+                               }
+                       }
+
+                       list_entry->freeze_has_probability = probability_of_use;
+
+                       if (probability_of_use && try_freeze != FALSE) {
+                               try_freeze = TRUE;
+                       } else {
+                               try_freeze = FALSE;
+                       }
+               } else {
+                       if (try_freeze != FALSE) {
+                               try_freeze = TRUE;
+                       }
+                       list_entry->freeze_has_probability = -1;
+               }
+
+               if (try_freeze) {
+                       uint32_t purgeable, wired, clean, dirty, shared;
+                       uint32_t max_pages = 0;
+                       int freezer_error_code = 0;
+
+                       error = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, &freezer_error_code, TRUE /* eval only */);
+
+                       if (error) {
+                               list_entry->p_freeze_error_code = freezer_error_code;
+                       }
+
+                       list_entry->freeze_attempted = TRUE;
+               }
+
+               list_entry++;
+
+               list_size += sizeof(proc_freezable_status_t);
+
+               p = memorystatus_get_next_proc_locked(&i, p, FALSE);
+               proc_count++;
+       }
+
+       proc_list_unlock();
+
+       buffer_size = list_size;
+
+       error = copyout(list_head, buffer, buffer_size);
+       if (error == 0) {
+               *retval = buffer_size;
+       } else {
+               *retval = 0;
+       }
+
+       list_size = sizeof(global_freezable_status_t) + (sizeof(proc_freezable_status_t) * MAX_FREEZABLE_PROCESSES);
+       kfree(list_head, list_size);
+
+       MEMORYSTATUS_DEBUG(1, "memorystatus_freezer_get_status: returning %d (%lu - size)\n", error, (unsigned long)*list_size);
+
+       return error;
+}
+
+static int
+memorystatus_freezer_control(int32_t flags, user_addr_t buffer, size_t buffer_size, int32_t *retval)
+{
+       int err = ENOTSUP;
+
+       if (flags == FREEZER_CONTROL_GET_STATUS) {
+               err = memorystatus_freezer_get_status(buffer, buffer_size, retval);
+       }
+
+       return err;
+}
+
+#endif /* CONFIG_FREEZE */
+
+#endif /* DEVELOPMENT || DEBUG */
+
+extern kern_return_t kernel_thread_start_priority(thread_continue_t continuation,
+    void *parameter,
+    integer_t priority,
+    thread_t *new_thread);
+
+#if DEVELOPMENT || DEBUG
+
+static int
+sysctl_memorystatus_disconnect_page_mappings SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int     error = 0, pid = 0;
+       proc_t  p;
+
+       error = sysctl_handle_int(oidp, &pid, 0, req);
+       if (error || !req->newptr) {
+               return error;
+       }
+
+       lck_mtx_lock(&disconnect_page_mappings_mutex);
+
+       if (pid == -1) {
+               vm_pageout_disconnect_all_pages();
+       } else {
+               p = proc_find(pid);
+
+               if (p != NULL) {
+                       error = task_disconnect_page_mappings(p->task);
+
+                       proc_rele(p);
+
+                       if (error) {
+                               error = EIO;
+                       }
+               } else {
+                       error = EINVAL;
+               }
+       }
+       lck_mtx_unlock(&disconnect_page_mappings_mutex);
+
+       return error;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_disconnect_page_mappings, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+    0, 0, &sysctl_memorystatus_disconnect_page_mappings, "I", "");
+
+#endif /* DEVELOPMENT || DEBUG */
+
+
+/*
+ * Picks the sorting routine for a given jetsam priority band.
+ *
+ * Input:
+ *     bucket_index - jetsam priority band to be sorted.
+ *     sort_order - JETSAM_SORT_xxx from kern_memorystatus.h
+ *             Currently sort_order is only meaningful when handling
+ *             coalitions.
+ *
+ * Return:
+ *     0     on success
+ *      non-0 on failure
+ */
+static int
+memorystatus_sort_bucket(unsigned int bucket_index, int sort_order)
+{
+       int coal_sort_order;
+
+       /*
+        * Verify the jetsam priority
+        */
+       if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
+               return EINVAL;
+       }
+
+#if DEVELOPMENT || DEBUG
+       if (sort_order == JETSAM_SORT_DEFAULT) {
+               coal_sort_order = COALITION_SORT_DEFAULT;
+       } else {
+               coal_sort_order = sort_order;           /* only used for testing scenarios */
+       }
+#else
+       /* Verify default */
+       if (sort_order == JETSAM_SORT_DEFAULT) {
+               coal_sort_order = COALITION_SORT_DEFAULT;
+       } else {
+               return EINVAL;
+       }
+#endif
+
+       proc_list_lock();
+
+       if (memstat_bucket[bucket_index].count == 0) {
+               proc_list_unlock();
+               return 0;
+       }
+
+       switch (bucket_index) {
+       case JETSAM_PRIORITY_FOREGROUND:
+               if (memorystatus_sort_by_largest_coalition_locked(bucket_index, coal_sort_order) == 0) {
                        /*
                         * Fall back to per process sorting when zero coalitions are found.
                         */
@@ -959,39 +1735,40 @@ static int memorystatus_sort_bucket(unsigned int bucket_index, int sort_order)
                break;
        }
        proc_list_unlock();
-       
-        return(0);
+
+       return 0;
 }
 
 /*
  * Sort processes by size for a single jetsam bucket.
  */
 
-static void memorystatus_sort_by_largest_process_locked(unsigned int bucket_index)
+static void
+memorystatus_sort_by_largest_process_locked(unsigned int bucket_index)
 {
        proc_t p = NULL, insert_after_proc = NULL, max_proc = NULL;
        proc_t next_p = NULL, prev_max_proc = NULL;
        uint32_t pages = 0, max_pages = 0;
        memstat_bucket_t *current_bucket;
-               
+
        if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
                return;
        }
-               
+
        current_bucket = &memstat_bucket[bucket_index];
 
        p = TAILQ_FIRST(&current_bucket->list);
 
        while (p) {
-               memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL, NULL);
+               memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL);
                max_pages = pages;
                max_proc = p;
                prev_max_proc = p;
-               
+
                while ((next_p = TAILQ_NEXT(p, p_memstat_list)) != NULL) {
                        /* traversing list until we find next largest process */
-                       p=next_p;
-                       memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL, NULL);
+                       p = next_p;
+                       memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL);
                        if (pages > max_pages) {
                                max_pages = pages;
                                max_proc = p;
@@ -1015,9 +1792,9 @@ static void memorystatus_sort_by_largest_process_locked(unsigned int bucket_inde
        }
 }
 
-#endif /* CONFIG_JETSAM */
-
-static proc_t memorystatus_get_first_proc_locked(unsigned int *bucket_index, boolean_t search) {
+static proc_t
+memorystatus_get_first_proc_locked(unsigned int *bucket_index, boolean_t search)
+{
        memstat_bucket_t *current_bucket;
        proc_t next_p;
 
@@ -1033,14 +1810,16 @@ static proc_t memorystatus_get_first_proc_locked(unsigned int *bucket_index, boo
                        next_p = TAILQ_FIRST(&current_bucket->list);
                }
        }
-       
+
        return next_p;
 }
 
-static proc_t memorystatus_get_next_proc_locked(unsigned int *bucket_index, proc_t p, boolean_t search) {
+static proc_t
+memorystatus_get_next_proc_locked(unsigned int *bucket_index, proc_t p, boolean_t search)
+{
        memstat_bucket_t *current_bucket;
        proc_t next_p;
-        
+
        if (!p || ((*bucket_index) >= MEMSTAT_BUCKET_COUNT)) {
                return NULL;
        }
@@ -1054,30 +1833,96 @@ static proc_t memorystatus_get_next_proc_locked(unsigned int *bucket_index, proc
        return next_p;
 }
 
+/*
+ * Structure to hold state for a jetsam thread.
+ * Typically there should be a single jetsam thread
+ * unless parallel jetsam is enabled.
+ */
+struct jetsam_thread_state {
+       boolean_t       inited; /* if the thread is initialized */
+       int             memorystatus_wakeup; /* wake channel */
+       int             index; /* jetsam thread index */
+       thread_t        thread; /* jetsam thread pointer */
+} *jetsam_threads;
+
+/* Maximum number of jetsam threads allowed */
+#define JETSAM_THREADS_LIMIT   3
+
+/* Number of active jetsam threads */
+_Atomic int active_jetsam_threads = 1;
+
+/* Number of maximum jetsam threads configured */
+int max_jetsam_threads = JETSAM_THREADS_LIMIT;
+
+/*
+ * Global switch for enabling fast jetsam. Fast jetsam is
+ * hooked up via the system_override() system call. It has the
+ * following effects:
+ * - Raise the jetsam threshold ("clear-the-deck")
+ * - Enabled parallel jetsam on eligible devices
+ */
+int fast_jetsam_enabled = 0;
+
+/* Routine to find the jetsam state structure for the current jetsam thread */
+static inline struct jetsam_thread_state *
+jetsam_current_thread(void)
+{
+       for (int thr_id = 0; thr_id < max_jetsam_threads; thr_id++) {
+               if (jetsam_threads[thr_id].thread == current_thread()) {
+                       return &(jetsam_threads[thr_id]);
+               }
+       }
+       panic("jetsam_current_thread() is being called from a non-jetsam thread\n");
+       /* Contol should not reach here */
+       return NULL;
+}
+
+
 __private_extern__ void
 memorystatus_init(void)
 {
-       thread_t thread = THREAD_NULL;
        kern_return_t result;
        int i;
 
 #if CONFIG_FREEZE
+       memorystatus_freeze_jetsam_band = JETSAM_PRIORITY_UI_SUPPORT;
+       memorystatus_frozen_processes_max = FREEZE_PROCESSES_MAX;
+       memorystatus_frozen_shared_mb_max = ((MAX_FROZEN_SHARED_MB_PERCENT * max_task_footprint_mb) / 100); /* 10% of the system wide task limit */
+       memorystatus_freeze_shared_mb_per_process_max = (memorystatus_frozen_shared_mb_max / 4);
        memorystatus_freeze_pages_min = FREEZE_PAGES_MIN;
        memorystatus_freeze_pages_max = FREEZE_PAGES_MAX;
+       memorystatus_max_frozen_demotions_daily = MAX_FROZEN_PROCESS_DEMOTIONS;
+       memorystatus_thaw_count_demotion_threshold = MIN_THAW_DEMOTION_THRESHOLD;
+#endif
+
+#if DEVELOPMENT || DEBUG
+       disconnect_page_mappings_lck_grp_attr = lck_grp_attr_alloc_init();
+       disconnect_page_mappings_lck_grp = lck_grp_alloc_init("disconnect_page_mappings", disconnect_page_mappings_lck_grp_attr);
+
+       lck_mtx_init(&disconnect_page_mappings_mutex, disconnect_page_mappings_lck_grp, NULL);
+
+       if (kill_on_no_paging_space == TRUE) {
+               max_kill_priority = JETSAM_PRIORITY_MAX;
+       }
 #endif
 
-       nanoseconds_to_absolutetime((uint64_t)DEFERRED_IDLE_EXIT_TIME_SECS * NSEC_PER_SEC, &memorystatus_idle_delay_time);
-       
+
        /* Init buckets */
        for (i = 0; i < MEMSTAT_BUCKET_COUNT; i++) {
                TAILQ_INIT(&memstat_bucket[i].list);
                memstat_bucket[i].count = 0;
        }
-       
        memorystatus_idle_demotion_call = thread_call_allocate((thread_call_func_t)memorystatus_perform_idle_demotion, NULL);
 
+#if CONFIG_JETSAM
+       nanoseconds_to_absolutetime((uint64_t)DEFERRED_IDLE_EXIT_TIME_SECS * NSEC_PER_SEC, &memorystatus_sysprocs_idle_delay_time);
+       nanoseconds_to_absolutetime((uint64_t)DEFERRED_IDLE_EXIT_TIME_SECS * NSEC_PER_SEC, &memorystatus_apps_idle_delay_time);
+
        /* Apply overrides */
        PE_get_default("kern.jetsam_delta", &delta_percentage, sizeof(delta_percentage));
+       if (delta_percentage == 0) {
+               delta_percentage = 5;
+       }
        assert(delta_percentage < 100);
        PE_get_default("kern.jetsam_critical_threshold", &critical_threshold_percentage, sizeof(critical_threshold_percentage));
        assert(critical_threshold_percentage < 100);
@@ -1087,80 +1932,177 @@ memorystatus_init(void)
        assert(pressure_threshold_percentage < 100);
        PE_get_default("kern.jetsam_freeze_threshold", &freeze_threshold_percentage, sizeof(freeze_threshold_percentage));
        assert(freeze_threshold_percentage < 100);
-       
-#if CONFIG_JETSAM
-       /* device tree can request to take snapshots for idle-exit kills by default */
-       PE_get_default("kern.jetsam_idle_snapshot", &memorystatus_idle_snapshot, sizeof(memorystatus_idle_snapshot));
+
+       if (!PE_parse_boot_argn("jetsam_aging_policy", &jetsam_aging_policy,
+           sizeof(jetsam_aging_policy))) {
+               if (!PE_get_default("kern.jetsam_aging_policy", &jetsam_aging_policy,
+                   sizeof(jetsam_aging_policy))) {
+                       jetsam_aging_policy = kJetsamAgingPolicyLegacy;
+               }
+       }
+
+       if (jetsam_aging_policy > kJetsamAgingPolicyMax) {
+               jetsam_aging_policy = kJetsamAgingPolicyLegacy;
+       }
+
+       switch (jetsam_aging_policy) {
+       case kJetsamAgingPolicyNone:
+               system_procs_aging_band = JETSAM_PRIORITY_IDLE;
+               applications_aging_band = JETSAM_PRIORITY_IDLE;
+               break;
+
+       case kJetsamAgingPolicyLegacy:
+               /*
+                * Legacy behavior where some daemons get a 10s protection once
+                * AND only before the first clean->dirty->clean transition before
+                * going into IDLE band.
+                */
+               system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+               applications_aging_band = JETSAM_PRIORITY_IDLE;
+               break;
+
+       case kJetsamAgingPolicySysProcsReclaimedFirst:
+               system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+               applications_aging_band = JETSAM_PRIORITY_AGING_BAND2;
+               break;
+
+       case kJetsamAgingPolicyAppsReclaimedFirst:
+               system_procs_aging_band = JETSAM_PRIORITY_AGING_BAND2;
+               applications_aging_band = JETSAM_PRIORITY_AGING_BAND1;
+               break;
+
+       default:
+               break;
+       }
+
+       /*
+        * The aging bands cannot overlap with the JETSAM_PRIORITY_ELEVATED_INACTIVE
+        * band and must be below it in priority. This is so that we don't have to make
+        * our 'aging' code worry about a mix of processes, some of which need to age
+        * and some others that need to stay elevated in the jetsam bands.
+        */
+       assert(JETSAM_PRIORITY_ELEVATED_INACTIVE > system_procs_aging_band);
+       assert(JETSAM_PRIORITY_ELEVATED_INACTIVE > applications_aging_band);
+
+       /* Take snapshots for idle-exit kills by default? First check the boot-arg... */
+       if (!PE_parse_boot_argn("jetsam_idle_snapshot", &memorystatus_idle_snapshot, sizeof(memorystatus_idle_snapshot))) {
+               /* ...no boot-arg, so check the device tree */
+               PE_get_default("kern.jetsam_idle_snapshot", &memorystatus_idle_snapshot, sizeof(memorystatus_idle_snapshot));
+       }
 
        memorystatus_delta = delta_percentage * atop_64(max_mem) / 100;
        memorystatus_available_pages_critical_idle_offset = idle_offset_percentage * atop_64(max_mem) / 100;
        memorystatus_available_pages_critical_base = (critical_threshold_percentage / delta_percentage) * memorystatus_delta;
-       
+       memorystatus_policy_more_free_offset_pages = (policy_more_free_offset_percentage / delta_percentage) * memorystatus_delta;
+
+       /* Jetsam Loop Detection */
+       if (max_mem <= (512 * 1024 * 1024)) {
+               /* 512 MB devices */
+               memorystatus_jld_eval_period_msecs = 8000;      /* 8000 msecs == 8 second window */
+       } else {
+               /* 1GB and larger devices */
+               memorystatus_jld_eval_period_msecs = 6000;      /* 6000 msecs == 6 second window */
+       }
+
+       memorystatus_jld_enabled = TRUE;
+
+       /* No contention at this point */
+       memorystatus_update_levels_locked(FALSE);
+
+#endif /* CONFIG_JETSAM */
+
        memorystatus_jetsam_snapshot_max = maxproc;
-       memorystatus_jetsam_snapshot = 
-               (memorystatus_jetsam_snapshot_t*)kalloc(sizeof(memorystatus_jetsam_snapshot_t) +
-               sizeof(memorystatus_jetsam_snapshot_entry_t) * memorystatus_jetsam_snapshot_max);
+
+       memorystatus_jetsam_snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) +
+           (sizeof(memorystatus_jetsam_snapshot_entry_t) * memorystatus_jetsam_snapshot_max);
+
+       memorystatus_jetsam_snapshot =
+           (memorystatus_jetsam_snapshot_t*)kalloc(memorystatus_jetsam_snapshot_size);
        if (!memorystatus_jetsam_snapshot) {
                panic("Could not allocate memorystatus_jetsam_snapshot");
        }
 
+       memorystatus_jetsam_snapshot_copy =
+           (memorystatus_jetsam_snapshot_t*)kalloc(memorystatus_jetsam_snapshot_size);
+       if (!memorystatus_jetsam_snapshot_copy) {
+               panic("Could not allocate memorystatus_jetsam_snapshot_copy");
+       }
+
        nanoseconds_to_absolutetime((uint64_t)JETSAM_SNAPSHOT_TIMEOUT_SECS * NSEC_PER_SEC, &memorystatus_jetsam_snapshot_timeout);
 
        memset(&memorystatus_at_boot_snapshot, 0, sizeof(memorystatus_jetsam_snapshot_t));
 
-       /* No contention at this point */
-       memorystatus_update_levels_locked(FALSE);
-
-       /* Jetsam Loop Detection */
-       if (max_mem <= (512 * 1024 * 1024)) {
-               /* 512 MB devices */
-               memorystatus_jld_eval_period_msecs = 8000;      /* 8000 msecs == 8 second window */
-       } else {
-               /* 1GB and larger devices */
-               memorystatus_jld_eval_period_msecs = 6000;      /* 6000 msecs == 6 second window */
-       }
-#endif
-       
 #if CONFIG_FREEZE
        memorystatus_freeze_threshold = (freeze_threshold_percentage / delta_percentage) * memorystatus_delta;
 #endif
-       
-       result = kernel_thread_start_priority(memorystatus_thread, NULL, 95 /* MAXPRI_KERNEL */, &thread);
-       if (result == KERN_SUCCESS) {
-               thread_deallocate(thread);
-       } else {
-               panic("Could not create memorystatus_thread");
+
+       /* Check the boot-arg to see if fast jetsam is allowed */
+       if (!PE_parse_boot_argn("fast_jetsam_enabled", &fast_jetsam_enabled, sizeof(fast_jetsam_enabled))) {
+               fast_jetsam_enabled = 0;
+       }
+
+       /* Check the boot-arg to configure the maximum number of jetsam threads */
+       if (!PE_parse_boot_argn("max_jetsam_threads", &max_jetsam_threads, sizeof(max_jetsam_threads))) {
+               max_jetsam_threads = JETSAM_THREADS_LIMIT;
+       }
+
+       /* Restrict the maximum number of jetsam threads to JETSAM_THREADS_LIMIT */
+       if (max_jetsam_threads > JETSAM_THREADS_LIMIT) {
+               max_jetsam_threads = JETSAM_THREADS_LIMIT;
+       }
+
+       /* For low CPU systems disable fast jetsam mechanism */
+       if (vm_pageout_state.vm_restricted_to_single_processor == TRUE) {
+               max_jetsam_threads = 1;
+               fast_jetsam_enabled = 0;
+       }
+
+       /* Initialize the jetsam_threads state array */
+       jetsam_threads = kalloc(sizeof(struct jetsam_thread_state) * max_jetsam_threads);
+
+       /* Initialize all the jetsam threads */
+       for (i = 0; i < max_jetsam_threads; i++) {
+               result = kernel_thread_start_priority(memorystatus_thread, NULL, 95 /* MAXPRI_KERNEL */, &jetsam_threads[i].thread);
+               if (result == KERN_SUCCESS) {
+                       jetsam_threads[i].inited = FALSE;
+                       jetsam_threads[i].index = i;
+                       thread_deallocate(jetsam_threads[i].thread);
+               } else {
+                       panic("Could not create memorystatus_thread %d", i);
+               }
        }
 }
 
 /* Centralised for the purposes of allowing panic-on-jetsam */
 extern void
-vm_wake_compactor_swapper(void);
+vm_run_compactor(void);
 
 /*
  * The jetsam no frills kill call
- *     Return: 0 on success
+ *      Return: 0 on success
  *             error code on failure (EINVAL...)
  */
 static int
-jetsam_do_kill(proc_t p, int jetsam_flags) {
+jetsam_do_kill(proc_t p, int jetsam_flags, os_reason_t jetsam_reason)
+{
        int error = 0;
-       error = exit1_internal(p, W_EXITCODE(0, SIGKILL), (int *)NULL, FALSE, FALSE, jetsam_flags);
-       return(error);
+       error = exit_with_reason(p, W_EXITCODE(0, SIGKILL), (int *)NULL, FALSE, FALSE, jetsam_flags, jetsam_reason);
+       return error;
 }
 
 /*
  * Wrapper for processes exiting with memorystatus details
  */
 static boolean_t
-memorystatus_do_kill(proc_t p, uint32_t cause) {
-
+memorystatus_do_kill(proc_t p, uint32_t cause, os_reason_t jetsam_reason)
+{
        int error = 0;
        __unused pid_t victim_pid = p->p_pid;
 
-       KERNEL_DEBUG_CONSTANT( (BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DO_KILL)) | DBG_FUNC_START,
-                              victim_pid, cause, vm_page_free_count, 0, 0);
+       KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DO_KILL)) | DBG_FUNC_START,
+           victim_pid, cause, vm_page_free_count, 0, 0);
 
+       DTRACE_MEMORYSTATUS3(memorystatus_do_kill, proc_t, p, os_reason_t, jetsam_reason, uint32_t, cause);
 #if CONFIG_JETSAM && (DEVELOPMENT || DEBUG)
        if (memorystatus_jetsam_panic_debug & (1 << cause)) {
                panic("memorystatus_do_kill(): jetsam debug panic (cause: %d)", cause);
@@ -1168,24 +2110,37 @@ memorystatus_do_kill(proc_t p, uint32_t cause) {
 #else
 #pragma unused(cause)
 #endif
+
+       if (p->p_memstat_effectivepriority >= JETSAM_PRIORITY_FOREGROUND) {
+               printf("memorystatus: killing process %d [%s] in high band %s (%d) - memorystatus_available_pages: %llu\n", p->p_pid,
+                   (*p->p_name ? p->p_name : "unknown"),
+                   memorystatus_priority_band_name(p->p_memstat_effectivepriority), p->p_memstat_effectivepriority,
+                   (uint64_t)memorystatus_available_pages);
+       }
+
+       /*
+        * The jetsam_reason (os_reason_t) has enough information about the kill cause.
+        * We don't really need jetsam_flags anymore, so it's okay that not all possible kill causes have been mapped.
+        */
        int jetsam_flags = P_LTERM_JETSAM;
        switch (cause) {
-               case kMemorystatusKilledHiwat:                  jetsam_flags |= P_JETSAM_HIWAT; break;
-               case kMemorystatusKilledVnodes:                 jetsam_flags |= P_JETSAM_VNODE; break;
-               case kMemorystatusKilledVMPageShortage:         jetsam_flags |= P_JETSAM_VMPAGESHORTAGE; break;
-               case kMemorystatusKilledVMThrashing:            jetsam_flags |= P_JETSAM_VMTHRASHING; break;
-               case kMemorystatusKilledFCThrashing:            jetsam_flags |= P_JETSAM_FCTHRASHING; break;
-               case kMemorystatusKilledPerProcessLimit:        jetsam_flags |= P_JETSAM_PID; break;
-               case kMemorystatusKilledIdleExit:               jetsam_flags |= P_JETSAM_IDLEEXIT; break;
+       case kMemorystatusKilledHiwat:                                          jetsam_flags |= P_JETSAM_HIWAT; break;
+       case kMemorystatusKilledVnodes:                                         jetsam_flags |= P_JETSAM_VNODE; break;
+       case kMemorystatusKilledVMPageShortage:                         jetsam_flags |= P_JETSAM_VMPAGESHORTAGE; break;
+       case kMemorystatusKilledVMCompressorThrashing:
+       case kMemorystatusKilledVMCompressorSpaceShortage:      jetsam_flags |= P_JETSAM_VMTHRASHING; break;
+       case kMemorystatusKilledFCThrashing:                            jetsam_flags |= P_JETSAM_FCTHRASHING; break;
+       case kMemorystatusKilledPerProcessLimit:                        jetsam_flags |= P_JETSAM_PID; break;
+       case kMemorystatusKilledIdleExit:                                       jetsam_flags |= P_JETSAM_IDLEEXIT; break;
        }
-       error = jetsam_do_kill(p, jetsam_flags);
+       error = jetsam_do_kill(p, jetsam_flags, jetsam_reason);
 
-       KERNEL_DEBUG_CONSTANT( (BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DO_KILL)) | DBG_FUNC_END, 
-                              victim_pid, cause, vm_page_free_count, error, 0);
+       KERNEL_DEBUG_CONSTANT((BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DO_KILL)) | DBG_FUNC_END,
+           victim_pid, cause, vm_page_free_count, error, 0);
 
-       vm_wake_compactor_swapper();
+       vm_run_compactor();
 
-       return (error == 0);
+       return error == 0;
 }
 
 /*
@@ -1193,164 +2148,349 @@ memorystatus_do_kill(proc_t p, uint32_t cause) {
  */
 
 static void
-memorystatus_check_levels_locked(void) {
+memorystatus_check_levels_locked(void)
+{
 #if CONFIG_JETSAM
        /* Update levels */
        memorystatus_update_levels_locked(TRUE);
-#endif
+#else /* CONFIG_JETSAM */
+       /*
+        * Nothing to do here currently since we update
+        * memorystatus_available_pages in vm_pressure_response.
+        */
+#endif /* CONFIG_JETSAM */
+}
+
+/*
+ * Pin a process to a particular jetsam band when it is in the background i.e. not doing active work.
+ * For an application: that means no longer in the FG band
+ * For a daemon: that means no longer in its 'requested' jetsam priority band
+ */
+
+int
+memorystatus_update_inactive_jetsam_priority_band(pid_t pid, uint32_t op_flags, int jetsam_prio, boolean_t effective_now)
+{
+       int error = 0;
+       boolean_t enable = FALSE;
+       proc_t  p = NULL;
+
+       if (op_flags == MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_ENABLE) {
+               enable = TRUE;
+       } else if (op_flags == MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_DISABLE) {
+               enable = FALSE;
+       } else {
+               return EINVAL;
+       }
+
+       p = proc_find(pid);
+       if (p != NULL) {
+               if ((enable && ((p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) == P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND)) ||
+                   (!enable && ((p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) == 0))) {
+                       /*
+                        * No change in state.
+                        */
+               } else {
+                       proc_list_lock();
+
+                       if (enable) {
+                               p->p_memstat_state |= P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND;
+                               memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+
+                               if (effective_now) {
+                                       if (p->p_memstat_effectivepriority < jetsam_prio) {
+                                               if (memorystatus_highwater_enabled) {
+                                                       /*
+                                                        * Process is about to transition from
+                                                        * inactive --> active
+                                                        * assign active state
+                                                        */
+                                                       boolean_t is_fatal;
+                                                       boolean_t use_active = TRUE;
+                                                       CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal);
+                                                       task_set_phys_footprint_limit_internal(p->task, (p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1, NULL, use_active, is_fatal);
+                                               }
+                                               memorystatus_update_priority_locked(p, jetsam_prio, FALSE, FALSE);
+                                       }
+                               } else {
+                                       if (isProcessInAgingBands(p)) {
+                                               memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, FALSE, TRUE);
+                                       }
+                               }
+                       } else {
+                               p->p_memstat_state &= ~P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND;
+                               memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+
+                               if (effective_now) {
+                                       if (p->p_memstat_effectivepriority == jetsam_prio) {
+                                               memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, FALSE, TRUE);
+                                       }
+                               } else {
+                                       if (isProcessInAgingBands(p)) {
+                                               memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, FALSE, TRUE);
+                                       }
+                               }
+                       }
+
+                       proc_list_unlock();
+               }
+               proc_rele(p);
+               error = 0;
+       } else {
+               error = ESRCH;
+       }
+
+       return error;
 }
 
 static void
-memorystatus_perform_idle_demotion(__unused void *spare1, __unused void *spare2) 
+memorystatus_perform_idle_demotion(__unused void *spare1, __unused void *spare2)
 {
        proc_t p;
-       uint64_t current_time;
+       uint64_t current_time = 0, idle_delay_time = 0;
+       int demote_prio_band = 0;
        memstat_bucket_t *demotion_bucket;
-   
+
        MEMORYSTATUS_DEBUG(1, "memorystatus_perform_idle_demotion()\n");
-   
+
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_IDLE_DEMOTE) | DBG_FUNC_START, 0, 0, 0, 0, 0);
-       current_time = mach_absolute_time();
+
+       current_time = mach_absolute_time();
+
        proc_list_lock();
 
-       demotion_bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE_DEFERRED];
-       p = TAILQ_FIRST(&demotion_bucket->list);
-           
-       while (p) {
-               MEMORYSTATUS_DEBUG(1, "memorystatus_perform_idle_demotion() found %d\n", p->p_pid);
-               
-               assert(p->p_memstat_idledeadline);
-               assert(p->p_memstat_dirty & P_DIRTY_DEFER_IN_PROGRESS);
-               assert((p->p_memstat_dirty & (P_DIRTY_IDLE_EXIT_ENABLED|P_DIRTY_IS_DIRTY)) == P_DIRTY_IDLE_EXIT_ENABLED);
-        
-               if (current_time >= p->p_memstat_idledeadline) {
-#if DEBUG || DEVELOPMENT
-                       if (!(p->p_memstat_dirty & P_DIRTY_MARKED)) {
-                               printf("memorystatus_perform_idle_demotion: moving process %d [%s] to idle band, but never dirtied (0x%x)!\n",
-                                       p->p_pid, (p->p_comm ? p->p_comm : "(unknown)"), p->p_memstat_dirty);
-                       }
-#endif
-                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
-                       memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, false);
-                       
-                       // The prior process has moved out of the demotion bucket, so grab the new head and continue
-                       p = TAILQ_FIRST(&demotion_bucket->list);
+       demote_prio_band = JETSAM_PRIORITY_IDLE + 1;
+
+       for (; demote_prio_band < JETSAM_PRIORITY_MAX; demote_prio_band++) {
+               if (demote_prio_band != system_procs_aging_band && demote_prio_band != applications_aging_band) {
                        continue;
                }
-               
-               // No further candidates
-               break;
+
+               demotion_bucket = &memstat_bucket[demote_prio_band];
+               p = TAILQ_FIRST(&demotion_bucket->list);
+
+               while (p) {
+                       MEMORYSTATUS_DEBUG(1, "memorystatus_perform_idle_demotion() found %d\n", p->p_pid);
+
+                       assert(p->p_memstat_idledeadline);
+
+                       assert(p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS);
+
+                       if (current_time >= p->p_memstat_idledeadline) {
+                               if ((isSysProc(p) &&
+                                   ((p->p_memstat_dirty & (P_DIRTY_IDLE_EXIT_ENABLED | P_DIRTY_IS_DIRTY)) != P_DIRTY_IDLE_EXIT_ENABLED)) || /* system proc marked dirty*/
+                                   task_has_assertions((struct task *)(p->task))) {     /* has outstanding assertions which might indicate outstanding work too */
+                                       idle_delay_time = (isSysProc(p)) ? memorystatus_sysprocs_idle_delay_time : memorystatus_apps_idle_delay_time;
+
+                                       p->p_memstat_idledeadline += idle_delay_time;
+                                       p = TAILQ_NEXT(p, p_memstat_list);
+                               } else {
+                                       proc_t next_proc = NULL;
+
+                                       next_proc = TAILQ_NEXT(p, p_memstat_list);
+                                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+
+                                       memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, false, true);
+
+                                       p = next_proc;
+                                       continue;
+                               }
+                       } else {
+                               // No further candidates
+                               break;
+                       }
+               }
        }
-       
+
        memorystatus_reschedule_idle_demotion_locked();
-       
+
        proc_list_unlock();
 
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_IDLE_DEMOTE) | DBG_FUNC_END, 0, 0, 0, 0, 0);
 }
 
 static void
-memorystatus_schedule_idle_demotion_locked(proc_t p, boolean_t set_state) 
-{      
-       boolean_t present_in_deferred_bucket = FALSE;
-       
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               present_in_deferred_bucket = TRUE;
+memorystatus_schedule_idle_demotion_locked(proc_t p, boolean_t set_state)
+{
+       boolean_t present_in_sysprocs_aging_bucket = FALSE;
+       boolean_t present_in_apps_aging_bucket = FALSE;
+       uint64_t  idle_delay_time = 0;
+
+       if (jetsam_aging_policy == kJetsamAgingPolicyNone) {
+               return;
+       }
+
+       if (p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) {
+               /*
+                * This process isn't going to be making the trip to the lower bands.
+                */
+               return;
+       }
+
+       if (isProcessInAgingBands(p)) {
+               if (jetsam_aging_policy != kJetsamAgingPolicyLegacy) {
+                       assert((p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS) != P_DIRTY_AGING_IN_PROGRESS);
+               }
+
+               if (isSysProc(p) && system_procs_aging_band) {
+                       present_in_sysprocs_aging_bucket = TRUE;
+               } else if (isApp(p) && applications_aging_band) {
+                       present_in_apps_aging_bucket = TRUE;
+               }
        }
 
-       MEMORYSTATUS_DEBUG(1, "memorystatus_schedule_idle_demotion_locked: scheduling demotion to idle band for pid %d (dirty:0x%x, set_state %d, demotions %d).\n", 
-           p->p_pid, p->p_memstat_dirty, set_state, memorystatus_scheduled_idle_demotions);
+       assert(!present_in_sysprocs_aging_bucket);
+       assert(!present_in_apps_aging_bucket);
 
-       assert((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED);
+       MEMORYSTATUS_DEBUG(1, "memorystatus_schedule_idle_demotion_locked: scheduling demotion to idle band for pid %d (dirty:0x%x, set_state %d, demotions %d).\n",
+           p->p_pid, p->p_memstat_dirty, set_state, (memorystatus_scheduled_idle_demotions_sysprocs + memorystatus_scheduled_idle_demotions_apps));
+
+       if (isSysProc(p)) {
+               assert((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED);
+       }
+
+       idle_delay_time = (isSysProc(p)) ? memorystatus_sysprocs_idle_delay_time : memorystatus_apps_idle_delay_time;
 
        if (set_state) {
-               assert(p->p_memstat_idledeadline == 0);
-               p->p_memstat_dirty |= P_DIRTY_DEFER_IN_PROGRESS;
-               p->p_memstat_idledeadline = mach_absolute_time() + memorystatus_idle_delay_time;
+               p->p_memstat_dirty |= P_DIRTY_AGING_IN_PROGRESS;
+               p->p_memstat_idledeadline = mach_absolute_time() + idle_delay_time;
        }
-       
+
        assert(p->p_memstat_idledeadline);
-       
-       if (present_in_deferred_bucket == FALSE) {
-               memorystatus_scheduled_idle_demotions++;
+
+       if (isSysProc(p) && present_in_sysprocs_aging_bucket == FALSE) {
+               memorystatus_scheduled_idle_demotions_sysprocs++;
+       } else if (isApp(p) && present_in_apps_aging_bucket == FALSE) {
+               memorystatus_scheduled_idle_demotions_apps++;
        }
 }
 
 static void
-memorystatus_invalidate_idle_demotion_locked(proc_t p, boolean_t clear_state) 
+memorystatus_invalidate_idle_demotion_locked(proc_t p, boolean_t clear_state)
 {
-       boolean_t present_in_deferred_bucket = FALSE;
-       
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               present_in_deferred_bucket = TRUE;
-               assert(p->p_memstat_idledeadline);
+       boolean_t present_in_sysprocs_aging_bucket = FALSE;
+       boolean_t present_in_apps_aging_bucket = FALSE;
+
+       if (!system_procs_aging_band && !applications_aging_band) {
+               return;
+       }
+
+       if ((p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS) == 0) {
+               return;
+       }
+
+       if (isProcessInAgingBands(p)) {
+               if (jetsam_aging_policy != kJetsamAgingPolicyLegacy) {
+                       assert((p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS) == P_DIRTY_AGING_IN_PROGRESS);
+               }
+
+               if (isSysProc(p) && system_procs_aging_band) {
+                       assert(p->p_memstat_effectivepriority == system_procs_aging_band);
+                       assert(p->p_memstat_idledeadline);
+                       present_in_sysprocs_aging_bucket = TRUE;
+               } else if (isApp(p) && applications_aging_band) {
+                       assert(p->p_memstat_effectivepriority == applications_aging_band);
+                       assert(p->p_memstat_idledeadline);
+                       present_in_apps_aging_bucket = TRUE;
+               }
        }
 
-       MEMORYSTATUS_DEBUG(1, "memorystatus_invalidate_idle_demotion(): invalidating demotion to idle band for pid %d (clear_state %d, demotions %d).\n", 
-           p->p_pid, clear_state, memorystatus_scheduled_idle_demotions);
-    
+       MEMORYSTATUS_DEBUG(1, "memorystatus_invalidate_idle_demotion(): invalidating demotion to idle band for pid %d (clear_state %d, demotions %d).\n",
+           p->p_pid, clear_state, (memorystatus_scheduled_idle_demotions_sysprocs + memorystatus_scheduled_idle_demotions_apps));
+
+
        if (clear_state) {
-               p->p_memstat_idledeadline = 0;
-               p->p_memstat_dirty &= ~P_DIRTY_DEFER_IN_PROGRESS;
+               p->p_memstat_idledeadline = 0;
+               p->p_memstat_dirty &= ~P_DIRTY_AGING_IN_PROGRESS;
        }
-       
-       if (present_in_deferred_bucket == TRUE) {
-               memorystatus_scheduled_idle_demotions--;
+
+       if (isSysProc(p) && present_in_sysprocs_aging_bucket == TRUE) {
+               memorystatus_scheduled_idle_demotions_sysprocs--;
+               assert(memorystatus_scheduled_idle_demotions_sysprocs >= 0);
+       } else if (isApp(p) && present_in_apps_aging_bucket == TRUE) {
+               memorystatus_scheduled_idle_demotions_apps--;
+               assert(memorystatus_scheduled_idle_demotions_apps >= 0);
        }
 
-       assert(memorystatus_scheduled_idle_demotions >= 0);
+       assert((memorystatus_scheduled_idle_demotions_sysprocs + memorystatus_scheduled_idle_demotions_apps) >= 0);
 }
 
 static void
-memorystatus_reschedule_idle_demotion_locked(void) {
-       if (0 == memorystatus_scheduled_idle_demotions) {
-               if (memstat_idle_demotion_deadline) {
-                       /* Transitioned 1->0, so cancel next call */
-                       thread_call_cancel(memorystatus_idle_demotion_call);
-                       memstat_idle_demotion_deadline = 0;
-               }
-       } else {
-               memstat_bucket_t *demotion_bucket;
-               proc_t p;
-               demotion_bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE_DEFERRED];
-               p = TAILQ_FIRST(&demotion_bucket->list);
-               
-               assert(p && p->p_memstat_idledeadline);
-               
-               if (memstat_idle_demotion_deadline != p->p_memstat_idledeadline){
-                       thread_call_enter_delayed(memorystatus_idle_demotion_call, p->p_memstat_idledeadline);
-                       memstat_idle_demotion_deadline = p->p_memstat_idledeadline;
-               }
-       }
-}
-
-/* 
+memorystatus_reschedule_idle_demotion_locked(void)
+{
+       if (0 == (memorystatus_scheduled_idle_demotions_sysprocs + memorystatus_scheduled_idle_demotions_apps)) {
+               if (memstat_idle_demotion_deadline) {
+                       /* Transitioned 1->0, so cancel next call */
+                       thread_call_cancel(memorystatus_idle_demotion_call);
+                       memstat_idle_demotion_deadline = 0;
+               }
+       } else {
+               memstat_bucket_t *demotion_bucket;
+               proc_t p = NULL, p1 = NULL, p2 = NULL;
+
+               if (system_procs_aging_band) {
+                       demotion_bucket = &memstat_bucket[system_procs_aging_band];
+                       p1 = TAILQ_FIRST(&demotion_bucket->list);
+
+                       p = p1;
+               }
+
+               if (applications_aging_band) {
+                       demotion_bucket = &memstat_bucket[applications_aging_band];
+                       p2 = TAILQ_FIRST(&demotion_bucket->list);
+
+                       if (p1 && p2) {
+                               p = (p1->p_memstat_idledeadline > p2->p_memstat_idledeadline) ? p2 : p1;
+                       } else {
+                               p = (p1 == NULL) ? p2 : p1;
+                       }
+               }
+
+               assert(p);
+
+               if (p != NULL) {
+                       assert(p && p->p_memstat_idledeadline);
+                       if (memstat_idle_demotion_deadline != p->p_memstat_idledeadline) {
+                               thread_call_enter_delayed(memorystatus_idle_demotion_call, p->p_memstat_idledeadline);
+                               memstat_idle_demotion_deadline = p->p_memstat_idledeadline;
+                       }
+               }
+       }
+}
+
+/*
  * List manipulation
  */
-int 
+
+int
 memorystatus_add(proc_t p, boolean_t locked)
 {
        memstat_bucket_t *bucket;
-       
+
        MEMORYSTATUS_DEBUG(1, "memorystatus_list_add(): adding pid %d with priority %d.\n", p->p_pid, p->p_memstat_effectivepriority);
-   
+
        if (!locked) {
-               proc_list_lock();
-       }
-       
+               proc_list_lock();
+       }
+
+       DTRACE_MEMORYSTATUS2(memorystatus_add, proc_t, p, int32_t, p->p_memstat_effectivepriority);
+
        /* Processes marked internal do not have priority tracked */
        if (p->p_memstat_state & P_MEMSTAT_INTERNAL) {
-                goto exit;
+               goto exit;
        }
-       
+
        bucket = &memstat_bucket[p->p_memstat_effectivepriority];
-       
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               assert(bucket->count == memorystatus_scheduled_idle_demotions);
+
+       if (isSysProc(p) && system_procs_aging_band && (p->p_memstat_effectivepriority == system_procs_aging_band)) {
+               assert(bucket->count == memorystatus_scheduled_idle_demotions_sysprocs - 1);
+       } else if (isApp(p) && applications_aging_band && (p->p_memstat_effectivepriority == applications_aging_band)) {
+               assert(bucket->count == memorystatus_scheduled_idle_demotions_apps - 1);
+       } else if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE) {
+               /*
+                * Entering the idle band.
+                * Record idle start time.
+                */
+               p->p_memstat_idle_start = mach_absolute_time();
        }
 
        TAILQ_INSERT_TAIL(&bucket->list, p, p_memstat_list);
@@ -1359,12 +2499,12 @@ memorystatus_add(proc_t p, boolean_t locked)
        memorystatus_list_count++;
 
        memorystatus_check_levels_locked();
-       
+
 exit:
-       if (!locked) {
-               proc_list_unlock();
-       }
-       
+       if (!locked) {
+               proc_list_unlock();
+       }
+
        return 0;
 }
 
@@ -1375,84 +2515,177 @@ exit:
  *
  *     Monitors transition between buckets and if necessary
  *     will update cached memory limits accordingly.
+ *
+ *     skip_demotion_check:
+ *     - if the 'jetsam aging policy' is NOT 'legacy':
+ *             When this flag is TRUE, it means we are going
+ *             to age the ripe processes out of the aging bands and into the
+ *             IDLE band and apply their inactive memory limits.
+ *
+ *     - if the 'jetsam aging policy' is 'legacy':
+ *             When this flag is TRUE, it might mean the above aging mechanism
+ *             OR
+ *             It might be that we have a process that has used up its 'idle deferral'
+ *             stay that is given to it once per lifetime. And in this case, the process
+ *             won't be going through any aging codepaths. But we still need to apply
+ *             the right inactive limits and so we explicitly set this to TRUE if the
+ *             new priority for the process is the IDLE band.
  */
-static void
-memorystatus_update_priority_locked(proc_t p, int priority, boolean_t head_insert)
+void
+memorystatus_update_priority_locked(proc_t p, int priority, boolean_t head_insert, boolean_t skip_demotion_check)
 {
        memstat_bucket_t *old_bucket, *new_bucket;
-       
+
        assert(priority < MEMSTAT_BUCKET_COUNT);
-       
+
        /* Ensure that exit isn't underway, leaving the proc retained but removed from its bucket */
        if ((p->p_listflag & P_LIST_EXITED) != 0) {
                return;
        }
-       
-       MEMORYSTATUS_DEBUG(1, "memorystatus_update_priority_locked(): setting pid %d to priority %d, inserting at %s\n",
-                          p->p_pid, priority, head_insert ? "head" : "tail");
+
+       MEMORYSTATUS_DEBUG(1, "memorystatus_update_priority_locked(): setting %s(%d) to priority %d, inserting at %s\n",
+           (*p->p_name ? p->p_name : "unknown"), p->p_pid, priority, head_insert ? "head" : "tail");
+
+       DTRACE_MEMORYSTATUS3(memorystatus_update_priority, proc_t, p, int32_t, p->p_memstat_effectivepriority, int, priority);
+
+#if DEVELOPMENT || DEBUG
+       if (priority == JETSAM_PRIORITY_IDLE && /* if the process is on its way into the IDLE band */
+           skip_demotion_check == FALSE &&     /* and it isn't via the path that will set the INACTIVE memlimits */
+           (p->p_memstat_dirty & P_DIRTY_TRACK) && /* and it has 'DIRTY' tracking enabled */
+           ((p->p_memstat_memlimit != p->p_memstat_memlimit_inactive) || /* and we notice that the current limit isn't the right value (inactive) */
+           ((p->p_memstat_state & P_MEMSTAT_MEMLIMIT_INACTIVE_FATAL) ? (!(p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT)) : (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT)))) { /* OR type (fatal vs non-fatal) */
+               panic("memorystatus_update_priority_locked: on %s with 0x%x, prio: %d and %d\n", p->p_name, p->p_memstat_state, priority, p->p_memstat_memlimit); /* then we must catch this */
+       }
+#endif /* DEVELOPMENT || DEBUG */
 
        old_bucket = &memstat_bucket[p->p_memstat_effectivepriority];
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               assert(old_bucket->count == (memorystatus_scheduled_idle_demotions + 1));
+
+       if (skip_demotion_check == FALSE) {
+               if (isSysProc(p)) {
+                       /*
+                        * For system processes, the memorystatus_dirty_* routines take care of adding/removing
+                        * the processes from the aging bands and balancing the demotion counts.
+                        * We can, however, override that if the process has an 'elevated inactive jetsam band' attribute.
+                        */
+
+                       if (p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) {
+                               /*
+                                * 2 types of processes can use the non-standard elevated inactive band:
+                                * - Frozen processes that always land in memorystatus_freeze_jetsam_band
+                                * OR
+                                * - processes that specifically opt-in to the elevated inactive support e.g. docked processes.
+                                */
+#if CONFIG_FREEZE
+                               if (p->p_memstat_state & P_MEMSTAT_FROZEN) {
+                                       if (priority <= memorystatus_freeze_jetsam_band) {
+                                               priority = memorystatus_freeze_jetsam_band;
+                                       }
+                               } else
+#endif /* CONFIG_FREEZE */
+                               {
+                                       if (priority <= JETSAM_PRIORITY_ELEVATED_INACTIVE) {
+                                               priority = JETSAM_PRIORITY_ELEVATED_INACTIVE;
+                                       }
+                               }
+                               assert(!(p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS));
+                       }
+               } else if (isApp(p)) {
+                       /*
+                        * Check to see if the application is being lowered in jetsam priority. If so, and:
+                        * - it has an 'elevated inactive jetsam band' attribute, then put it in the appropriate band.
+                        * - it is a normal application, then let it age in the aging band if that policy is in effect.
+                        */
+
+                       if (p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) {
+#if CONFIG_FREEZE
+                               if (p->p_memstat_state & P_MEMSTAT_FROZEN) {
+                                       if (priority <= memorystatus_freeze_jetsam_band) {
+                                               priority = memorystatus_freeze_jetsam_band;
+                                       }
+                               } else
+#endif /* CONFIG_FREEZE */
+                               {
+                                       if (priority <= JETSAM_PRIORITY_ELEVATED_INACTIVE) {
+                                               priority = JETSAM_PRIORITY_ELEVATED_INACTIVE;
+                                       }
+                               }
+                       } else {
+                               if (applications_aging_band) {
+                                       if (p->p_memstat_effectivepriority == applications_aging_band) {
+                                               assert(old_bucket->count == (memorystatus_scheduled_idle_demotions_apps + 1));
+                                       }
+
+                                       if ((jetsam_aging_policy != kJetsamAgingPolicyLegacy) && (priority <= applications_aging_band)) {
+                                               assert(!(p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS));
+                                               priority = applications_aging_band;
+                                               memorystatus_schedule_idle_demotion_locked(p, TRUE);
+                                       }
+                               }
+                       }
+               }
+       }
+
+       if ((system_procs_aging_band && (priority == system_procs_aging_band)) || (applications_aging_band && (priority == applications_aging_band))) {
+               assert(p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS);
        }
 
        TAILQ_REMOVE(&old_bucket->list, p, p_memstat_list);
        old_bucket->count--;
-       
-       new_bucket = &memstat_bucket[priority]; 
-       if (head_insert)
+
+       new_bucket = &memstat_bucket[priority];
+       if (head_insert) {
                TAILQ_INSERT_HEAD(&new_bucket->list, p, p_memstat_list);
-       else
+       } else {
                TAILQ_INSERT_TAIL(&new_bucket->list, p, p_memstat_list);
+       }
        new_bucket->count++;
 
-#if CONFIG_JETSAM
        if (memorystatus_highwater_enabled) {
-               boolean_t trigger_exception;
+               boolean_t is_fatal;
+               boolean_t use_active;
 
-               /* 
+               /*
                 * If cached limit data is updated, then the limits
                 * will be enforced by writing to the ledgers.
                 */
                boolean_t ledger_update_needed = TRUE;
 
                /*
-                * No need to consider P_MEMSTAT_MEMLIMIT_BACKGROUND anymore.
-                * Background limits are described via the inactive limit slots.
-                *
-                * Here, we must update the cached memory limit if the task 
+                * Here, we must update the cached memory limit if the task
                 * is transitioning between:
-                *      active <--> inactive
+                *      active <--> inactive
                 *      FG     <-->       BG
                 * but:
                 *      dirty  <-->    clean   is ignored
                 *
-                * We bypass processes that have opted into dirty tracking because
+                * We bypass non-idle processes that have opted into dirty tracking because
                 * a move between buckets does not imply a transition between the
                 * dirty <--> clean state.
-                * Setting limits on processes opted into dirty tracking is handled
-                * in memorystatus_dirty_set() where the transition is very clear.
                 */
 
                if (p->p_memstat_dirty & P_DIRTY_TRACK) {
-
-                       ledger_update_needed = FALSE;
-
+                       if (skip_demotion_check == TRUE && priority == JETSAM_PRIORITY_IDLE) {
+                               CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal);
+                               use_active = FALSE;
+                       } else {
+                               ledger_update_needed = FALSE;
+                       }
                } else if ((priority >= JETSAM_PRIORITY_FOREGROUND) && (p->p_memstat_effectivepriority < JETSAM_PRIORITY_FOREGROUND)) {
                        /*
-                        *      inactive --> active
+                        *      inactive --> active
                         *      BG       -->     FG
                         *      assign active state
                         */
-                       CACHE_ACTIVE_LIMITS_LOCKED(p, trigger_exception);
-
+                       CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal);
+                       use_active = TRUE;
                } else if ((priority < JETSAM_PRIORITY_FOREGROUND) && (p->p_memstat_effectivepriority >= JETSAM_PRIORITY_FOREGROUND)) {
                        /*
-                        *      active --> inactive
+                        *      active --> inactive
                         *      FG     -->       BG
                         *      assign inactive state
                         */
-                       CACHE_INACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                       CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal);
+                       use_active = FALSE;
                } else {
                        /*
                         * The transition between jetsam priority buckets apparently did
@@ -1467,19 +2700,63 @@ memorystatus_update_priority_locked(proc_t p, int priority, boolean_t head_inser
                 * Enforce the new limits by writing to the ledger
                 */
                if (ledger_update_needed) {
-                       task_set_phys_footprint_limit_internal(p->task, (p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1, NULL, trigger_exception);
+                       task_set_phys_footprint_limit_internal(p->task, (p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1, NULL, use_active, is_fatal);
 
                        MEMORYSTATUS_DEBUG(3, "memorystatus_update_priority_locked: new limit on pid %d (%dMB %s) priority old --> new (%d --> %d) dirty?=0x%x %s\n",
-                                          p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
-                                          (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), p->p_memstat_effectivepriority, priority, p->p_memstat_dirty,
-                                          (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
+                           p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
+                           (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), p->p_memstat_effectivepriority, priority, p->p_memstat_dirty,
+                           (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
+               }
+       }
+
+       /*
+        * Record idle start or idle delta.
+        */
+       if (p->p_memstat_effectivepriority == priority) {
+               /*
+                * This process is not transitioning between
+                * jetsam priority buckets.  Do nothing.
+                */
+       } else if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE) {
+               uint64_t now;
+               /*
+                * Transitioning out of the idle priority bucket.
+                * Record idle delta.
+                */
+               assert(p->p_memstat_idle_start != 0);
+               now = mach_absolute_time();
+               if (now > p->p_memstat_idle_start) {
+                       p->p_memstat_idle_delta = now - p->p_memstat_idle_start;
+               }
+
+               /*
+                * About to become active and so memory footprint could change.
+                * So mark it eligible for freeze-considerations next time around.
+                */
+               if (p->p_memstat_state & P_MEMSTAT_FREEZE_IGNORE) {
+                       p->p_memstat_state &= ~P_MEMSTAT_FREEZE_IGNORE;
                }
+       } else if (priority == JETSAM_PRIORITY_IDLE) {
+               /*
+                * Transitioning into the idle priority bucket.
+                * Record idle start.
+                */
+               p->p_memstat_idle_start = mach_absolute_time();
        }
 
-#endif  /* CONFIG_JETSAM */
-       
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_CHANGE_PRIORITY), p->p_pid, priority, p->p_memstat_effectivepriority, 0, 0);
+
        p->p_memstat_effectivepriority = priority;
-       
+
+#if CONFIG_SECLUDED_MEMORY
+       if (secluded_for_apps &&
+           task_could_use_secluded_mem(p->task)) {
+               task_set_can_use_secluded_mem(
+                       p->task,
+                       (priority >= JETSAM_PRIORITY_FOREGROUND));
+       }
+#endif /* CONFIG_SECLUDED_MEMORY */
+
        memorystatus_check_levels_locked();
 }
 
@@ -1508,39 +2785,28 @@ memorystatus_update_priority_locked(proc_t p, int priority, boolean_t head_inser
  *     memlimit_inactive_is_fatal  When a process is inactive and exceeds its memory footprint,
  *                                 this describes whether or not it should be immediatly fatal.
  *
- *     memlimit_background     This process has a high-water-mark while in the background.
- *                             No longer meaningful.  Background limits are described via
- *                             the inactive slots.  Flag is ignored.
- *
- *
  * Returns:     0      Success
  *             non-0   Failure
  */
 
 int
 memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effective, boolean_t update_memlimit,
-                   int32_t memlimit_active,   boolean_t memlimit_active_is_fatal,
-                    int32_t memlimit_inactive, boolean_t memlimit_inactive_is_fatal,
-                    __unused boolean_t memlimit_background)
+    int32_t memlimit_active, boolean_t memlimit_active_is_fatal,
+    int32_t memlimit_inactive, boolean_t memlimit_inactive_is_fatal)
 {
        int ret;
        boolean_t head_insert = false;
-       
-#if !CONFIG_JETSAM
-#pragma unused(update_memlimit, memlimit_active, memlimit_inactive)
-#pragma unused(memlimit_active_is_fatal, memlimit_inactive_is_fatal)
-#endif /* !CONFIG_JETSAM */
 
-       MEMORYSTATUS_DEBUG(1, "memorystatus_update: changing pid %d: priority %d, user_data 0x%llx\n", p->p_pid, priority, user_data);
+       MEMORYSTATUS_DEBUG(1, "memorystatus_update: changing (%s) pid %d: priority %d, user_data 0x%llx\n", (*p->p_name ? p->p_name : "unknown"), p->p_pid, priority, user_data);
 
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_UPDATE) | DBG_FUNC_START, p->p_pid, priority, user_data, effective, 0);
-       
+
        if (priority == -1) {
                /* Use as shorthand for default priority */
                priority = JETSAM_PRIORITY_DEFAULT;
-       } else if (priority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               /* JETSAM_PRIORITY_IDLE_DEFERRED is reserved for internal use; if requested, adjust to JETSAM_PRIORITY_IDLE. */
-               priority = JETSAM_PRIORITY_IDLE;                
+       } else if ((priority == system_procs_aging_band) || (priority == applications_aging_band)) {
+               /* Both the aging bands are reserved for internal use; if requested, adjust to JETSAM_PRIORITY_IDLE. */
+               priority = JETSAM_PRIORITY_IDLE;
        } else if (priority == JETSAM_PRIORITY_IDLE_HEAD) {
                /* JETSAM_PRIORITY_IDLE_HEAD inserts at the head of the idle queue */
                priority = JETSAM_PRIORITY_IDLE;
@@ -1552,14 +2818,14 @@ memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effect
        }
 
        proc_list_lock();
-       
+
        assert(!(p->p_memstat_state & P_MEMSTAT_INTERNAL));
 
        if (effective && (p->p_memstat_state & P_MEMSTAT_PRIORITYUPDATED)) {
                ret = EALREADY;
                proc_list_unlock();
                MEMORYSTATUS_DEBUG(1, "memorystatus_update: effective change specified for pid %d, but change already occurred.\n", p->p_pid);
-               goto out;             
+               goto out;
        }
 
        if ((p->p_memstat_state & P_MEMSTAT_TERMINATED) || ((p->p_listflag & P_LIST_EXITED) != 0)) {
@@ -1568,16 +2834,16 @@ memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effect
                 */
                ret = EBUSY;
                proc_list_unlock();
-               goto out;             
+               goto out;
        }
 
        p->p_memstat_state |= P_MEMSTAT_PRIORITYUPDATED;
        p->p_memstat_userdata = user_data;
        p->p_memstat_requestedpriority = priority;
-       
-#if CONFIG_JETSAM
+
        if (update_memlimit) {
-               boolean_t trigger_exception;
+               boolean_t is_fatal;
+               boolean_t use_active;
 
                /*
                 * Posix_spawn'd processes come through this path to instantiate ledger limits.
@@ -1586,26 +2852,9 @@ memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effect
                 */
 
                MEMORYSTATUS_DEBUG(3, "memorystatus_update(enter): pid %d, priority %d, dirty=0x%x, Active(%dMB %s), Inactive(%dMB, %s)\n",
-                                  p->p_pid, priority, p->p_memstat_dirty,
-                                  memlimit_active,   (memlimit_active_is_fatal ? "F " : "NF"),
-                                  memlimit_inactive, (memlimit_inactive_is_fatal ? "F " : "NF"));
-
-               if (memlimit_background) {
-
-                       /*
-                        * With 2-level HWM support, we no longer honor P_MEMSTAT_MEMLIMIT_BACKGROUND.
-                        * Background limits are described via the inactive limit slots.
-                        */
-
-                       // p->p_memstat_state |= P_MEMSTAT_MEMLIMIT_BACKGROUND;
-
-#if DEVELOPMENT || DEBUG
-                       printf("memorystatus_update: WARNING %s[%d] set unused flag P_MEMSTAT_MEMLIMIT_BACKGROUND [A==%dMB %s] [IA==%dMB %s]\n",
-                              (p->p_comm ? p->p_comm : "unknown"), p->p_pid,
-                              memlimit_active, (memlimit_active_is_fatal ? "F " : "NF"),
-                              memlimit_inactive, (memlimit_inactive_is_fatal ? "F " : "NF"));
-#endif /* DEVELOPMENT || DEBUG */
-               }
+                   p->p_pid, priority, p->p_memstat_dirty,
+                   memlimit_active, (memlimit_active_is_fatal ? "F " : "NF"),
+                   memlimit_inactive, (memlimit_inactive_is_fatal ? "F " : "NF"));
 
                if (memlimit_active <= 0) {
                        /*
@@ -1618,7 +2867,7 @@ memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effect
                        /*
                         * For backward compatibility with some unexplained launchd behavior,
                         * we allow a zero sized limit.  But we still enforce system_wide limit
-                        * when written to the ledgers.  
+                        * when written to the ledgers.
                         */
 
                        if (memlimit_active < 0) {
@@ -1656,9 +2905,11 @@ memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effect
                 */
 
                if (proc_jetsam_state_is_active_locked(p) == TRUE) {
-                       CACHE_ACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                       CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal);
+                       use_active = TRUE;
                } else {
-                       CACHE_INACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                       CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal);
+                       use_active = FALSE;
                }
 
                /*
@@ -1666,30 +2917,40 @@ memorystatus_update(proc_t p, int priority, uint64_t user_data, boolean_t effect
                 */
                if (memorystatus_highwater_enabled) {
                        /* apply now */
-                       assert(trigger_exception == TRUE);
-                       task_set_phys_footprint_limit_internal(p->task, ((p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1), NULL, trigger_exception);
+                       task_set_phys_footprint_limit_internal(p->task, ((p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1), NULL, use_active, is_fatal);
 
                        MEMORYSTATUS_DEBUG(3, "memorystatus_update: init: limit on pid %d (%dMB %s) targeting priority(%d) dirty?=0x%x %s\n",
-                                          p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
-                                          (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), priority, p->p_memstat_dirty,
-                                          (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
+                           p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
+                           (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), priority, p->p_memstat_dirty,
+                           (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
                }
        }
-#endif /* CONFIG_JETSAM */
 
        /*
-        * We can't add to the JETSAM_PRIORITY_IDLE_DEFERRED bucket here.
-        * But, we could be removing it from the bucket.
+        * We can't add to the aging bands buckets here.
+        * But, we could be removing it from those buckets.
         * Check and take appropriate steps if so.
         */
-       
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               
+
+       if (isProcessInAgingBands(p)) {
                memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+               memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, FALSE, TRUE);
+       } else {
+               if (jetsam_aging_policy == kJetsamAgingPolicyLegacy && priority == JETSAM_PRIORITY_IDLE) {
+                       /*
+                        * Daemons with 'inactive' limits will go through the dirty tracking codepath.
+                        * This path deals with apps that may have 'inactive' limits e.g. WebContent processes.
+                        * If this is the legacy aging policy we explicitly need to apply those limits. If it
+                        * is any other aging policy, then we don't need to worry because all processes
+                        * will go through the aging bands and then the demotion thread will take care to
+                        * move them into the IDLE band and apply the required limits.
+                        */
+                       memorystatus_update_priority_locked(p, priority, head_insert, TRUE);
+               }
        }
-       
-       memorystatus_update_priority_locked(p, priority, head_insert);
-       
+
+       memorystatus_update_priority_locked(p, priority, head_insert, FALSE);
+
        proc_list_unlock();
        ret = 0;
 
@@ -1704,18 +2965,35 @@ memorystatus_remove(proc_t p, boolean_t locked)
 {
        int ret;
        memstat_bucket_t *bucket;
+       boolean_t       reschedule = FALSE;
 
        MEMORYSTATUS_DEBUG(1, "memorystatus_list_remove: removing pid %d\n", p->p_pid);
 
-       if (!locked) {
-               proc_list_lock();
-       }
+       if (!locked) {
+               proc_list_lock();
+       }
 
        assert(!(p->p_memstat_state & P_MEMSTAT_INTERNAL));
-       
+
        bucket = &memstat_bucket[p->p_memstat_effectivepriority];
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-               assert(bucket->count == memorystatus_scheduled_idle_demotions);
+
+       if (isSysProc(p) && system_procs_aging_band && (p->p_memstat_effectivepriority == system_procs_aging_band)) {
+               assert(bucket->count == memorystatus_scheduled_idle_demotions_sysprocs);
+               reschedule = TRUE;
+       } else if (isApp(p) && applications_aging_band && (p->p_memstat_effectivepriority == applications_aging_band)) {
+               assert(bucket->count == memorystatus_scheduled_idle_demotions_apps);
+               reschedule = TRUE;
+       }
+
+       /*
+        * Record idle delta
+        */
+
+       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE) {
+               uint64_t now = mach_absolute_time();
+               if (now > p->p_memstat_idle_start) {
+                       p->p_memstat_idle_delta = now - p->p_memstat_idle_start;
+               }
        }
 
        TAILQ_REMOVE(&bucket->list, p, p_memstat_list);
@@ -1724,30 +3002,36 @@ memorystatus_remove(proc_t p, boolean_t locked)
        memorystatus_list_count--;
 
        /* If awaiting demotion to the idle band, clean up */
-       if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
+       if (reschedule) {
                memorystatus_invalidate_idle_demotion_locked(p, TRUE);
-               memorystatus_reschedule_idle_demotion_locked();
+               memorystatus_reschedule_idle_demotion_locked();
        }
 
        memorystatus_check_levels_locked();
 
-#if CONFIG_FREEZE    
+#if CONFIG_FREEZE
        if (p->p_memstat_state & (P_MEMSTAT_FROZEN)) {
+               if (p->p_memstat_state & P_MEMSTAT_REFREEZE_ELIGIBLE) {
+                       p->p_memstat_state &= ~P_MEMSTAT_REFREEZE_ELIGIBLE;
+                       memorystatus_refreeze_eligible_count--;
+               }
+
                memorystatus_frozen_count--;
+               memorystatus_frozen_shared_mb -= p->p_memstat_freeze_sharedanon_pages;
+               p->p_memstat_freeze_sharedanon_pages = 0;
        }
 
        if (p->p_memstat_state & P_MEMSTAT_SUSPENDED) {
-               memorystatus_suspended_footprint_total -= p->p_memstat_suspendedfootprint;
                memorystatus_suspended_count--;
        }
 #endif
 
-       if (!locked) {
-               proc_list_unlock();
-       }
+       if (!locked) {
+               proc_list_unlock();
+       }
 
        if (p) {
-               ret = 0; 
+               ret = 0;
        } else {
                ret = ESRCH;
        }
@@ -1760,53 +3044,91 @@ memorystatus_remove(proc_t p, boolean_t locked)
  *
  * Return:
  *     0     on success
- *     non-0 on failure
+ *      non-0 on failure
+ *
+ * The proc_list_lock is held by the caller.
  */
 
 static int
-memorystatus_validate_track_flags(struct proc *target_p, uint32_t pcontrol) {
+memorystatus_validate_track_flags(struct proc *target_p, uint32_t pcontrol)
+{
        /* See that the process isn't marked for termination */
        if (target_p->p_memstat_dirty & P_DIRTY_TERMINATED) {
                return EBUSY;
        }
-       
+
        /* Idle exit requires that process be tracked */
        if ((pcontrol & PROC_DIRTY_ALLOW_IDLE_EXIT) &&
-          !(pcontrol & PROC_DIRTY_TRACK)) {
+           !(pcontrol & PROC_DIRTY_TRACK)) {
                return EINVAL;
        }
 
        /* 'Launch in progress' tracking requires that process have enabled dirty tracking too. */
        if ((pcontrol & PROC_DIRTY_LAUNCH_IN_PROGRESS) &&
-          !(pcontrol & PROC_DIRTY_TRACK)) {
+           !(pcontrol & PROC_DIRTY_TRACK)) {
+               return EINVAL;
+       }
+
+       /* Only one type of DEFER behavior is allowed.*/
+       if ((pcontrol & PROC_DIRTY_DEFER) &&
+           (pcontrol & PROC_DIRTY_DEFER_ALWAYS)) {
                return EINVAL;
        }
 
        /* Deferral is only relevant if idle exit is specified */
-       if ((pcontrol & PROC_DIRTY_DEFER) && 
-          !(pcontrol & PROC_DIRTY_ALLOWS_IDLE_EXIT)) {
+       if (((pcontrol & PROC_DIRTY_DEFER) ||
+           (pcontrol & PROC_DIRTY_DEFER_ALWAYS)) &&
+           !(pcontrol & PROC_DIRTY_ALLOWS_IDLE_EXIT)) {
                return EINVAL;
        }
-       
-       return(0);
+
+       return 0;
 }
 
 static void
-memorystatus_update_idle_priority_locked(proc_t p) {
+memorystatus_update_idle_priority_locked(proc_t p)
+{
        int32_t priority;
 
        MEMORYSTATUS_DEBUG(1, "memorystatus_update_idle_priority_locked(): pid %d dirty 0x%X\n", p->p_pid, p->p_memstat_dirty);
-       
-       if ((p->p_memstat_dirty & (P_DIRTY_IDLE_EXIT_ENABLED|P_DIRTY_IS_DIRTY)) == P_DIRTY_IDLE_EXIT_ENABLED) {
-               priority = (p->p_memstat_dirty & P_DIRTY_DEFER_IN_PROGRESS) ? JETSAM_PRIORITY_IDLE_DEFERRED : JETSAM_PRIORITY_IDLE;
+
+       assert(isSysProc(p));
+
+       if ((p->p_memstat_dirty & (P_DIRTY_IDLE_EXIT_ENABLED | P_DIRTY_IS_DIRTY)) == P_DIRTY_IDLE_EXIT_ENABLED) {
+               priority = (p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS) ? system_procs_aging_band : JETSAM_PRIORITY_IDLE;
        } else {
                priority = p->p_memstat_requestedpriority;
        }
-       
+
        if (priority != p->p_memstat_effectivepriority) {
-               memorystatus_update_priority_locked(p, priority, false);
+               if ((jetsam_aging_policy == kJetsamAgingPolicyLegacy) &&
+                   (priority == JETSAM_PRIORITY_IDLE)) {
+                       /*
+                        * This process is on its way into the IDLE band. The system is
+                        * using 'legacy' jetsam aging policy. That means, this process
+                        * has already used up its idle-deferral aging time that is given
+                        * once per its lifetime. So we need to set the INACTIVE limits
+                        * explicitly because it won't be going through the demotion paths
+                        * that take care to apply the limits appropriately.
+                        */
+
+                       if (p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) {
+                               /*
+                                * This process has the 'elevated inactive jetsam band' attribute.
+                                * So, there will be no trip to IDLE after all.
+                                * Instead, we pin the process in the elevated band,
+                                * where its ACTIVE limits will apply.
+                                */
+
+                               priority = JETSAM_PRIORITY_ELEVATED_INACTIVE;
+                       }
+
+                       memorystatus_update_priority_locked(p, priority, false, true);
+               } else {
+                       memorystatus_update_priority_locked(p, priority, false, false);
+               }
        }
-} 
+}
 
 /*
  * Processes can opt to have their state tracked by the kernel, indicating  when they are busy (dirty) or idle
@@ -1815,7 +3137,7 @@ memorystatus_update_idle_priority_locked(proc_t p) {
  * priority idle band when clean (and killed earlier, protecting higher priority procesess).
  *
  * If the deferral flag is set, then newly tracked processes will be protected for an initial period (as determined by
- * memorystatus_idle_delay_time); if they go clean during this time, then they will be moved to a deferred-idle band
+ * memorystatus_sysprocs_idle_delay_time); if they go clean during this time, then they will be moved to a deferred-idle band
  * with a slightly higher priority, guarding against immediate termination under memory pressure and being unable to
  * make forward progress. Finally, when the guard expires, they will be moved to the standard, lowest-priority, idle
  * band. The deferral can be cleared early by clearing the appropriate flag.
@@ -1826,18 +3148,19 @@ memorystatus_update_idle_priority_locked(proc_t p) {
  */
 
 int
-memorystatus_dirty_track(proc_t p, uint32_t pcontrol) {
+memorystatus_dirty_track(proc_t p, uint32_t pcontrol)
+{
        unsigned int old_dirty;
        boolean_t reschedule = FALSE;
        boolean_t already_deferred = FALSE;
        boolean_t defer_now = FALSE;
        int ret = 0;
-    
+
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DIRTY_TRACK),
-               p->p_pid, p->p_memstat_dirty, pcontrol, 0, 0);
-       
+           p->p_pid, p->p_memstat_dirty, pcontrol, 0, 0);
+
        proc_list_lock();
-       
+
        if ((p->p_listflag & P_LIST_EXITED) != 0) {
                /*
                 * Process is on its way out.
@@ -1850,13 +3173,13 @@ memorystatus_dirty_track(proc_t p, uint32_t pcontrol) {
                ret = EPERM;
                goto exit;
        }
-       
+
        if ((ret = memorystatus_validate_track_flags(p, pcontrol)) != 0) {
                /* error  */
                goto exit;
        }
 
-        old_dirty = p->p_memstat_dirty;
+       old_dirty = p->p_memstat_dirty;
 
        /* These bits are cumulative, as per <rdar://problem/11159924> */
        if (pcontrol & PROC_DIRTY_TRACK) {
@@ -1864,69 +3187,91 @@ memorystatus_dirty_track(proc_t p, uint32_t pcontrol) {
        }
 
        if (pcontrol & PROC_DIRTY_ALLOW_IDLE_EXIT) {
-               p->p_memstat_dirty |= P_DIRTY_ALLOW_IDLE_EXIT;                                  
+               p->p_memstat_dirty |= P_DIRTY_ALLOW_IDLE_EXIT;
        }
 
        if (pcontrol & PROC_DIRTY_LAUNCH_IN_PROGRESS) {
                p->p_memstat_dirty |= P_DIRTY_LAUNCH_IN_PROGRESS;
        }
 
-       if (old_dirty & P_DIRTY_DEFER_IN_PROGRESS) {
+       if (old_dirty & P_DIRTY_AGING_IN_PROGRESS) {
                already_deferred = TRUE;
        }
 
-       /* This can be set and cleared exactly once. */
-       if (pcontrol & PROC_DIRTY_DEFER) {
 
-               if ( !(old_dirty & P_DIRTY_DEFER)) {
+       /* This can be set and cleared exactly once. */
+       if (pcontrol & (PROC_DIRTY_DEFER | PROC_DIRTY_DEFER_ALWAYS)) {
+               if ((pcontrol & (PROC_DIRTY_DEFER)) &&
+                   !(old_dirty & P_DIRTY_DEFER)) {
                        p->p_memstat_dirty |= P_DIRTY_DEFER;
                }
 
+               if ((pcontrol & (PROC_DIRTY_DEFER_ALWAYS)) &&
+                   !(old_dirty & P_DIRTY_DEFER_ALWAYS)) {
+                       p->p_memstat_dirty |= P_DIRTY_DEFER_ALWAYS;
+               }
+
                defer_now = TRUE;
        }
 
        MEMORYSTATUS_DEBUG(1, "memorystatus_on_track_dirty(): set idle-exit %s / defer %s / dirty %s for pid %d\n",
-               ((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED) ? "Y" : "N",
-               defer_now ? "Y" : "N",
-               p->p_memstat_dirty & P_DIRTY ? "Y" : "N",
-               p->p_pid);
+           ((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED) ? "Y" : "N",
+           defer_now ? "Y" : "N",
+           p->p_memstat_dirty & P_DIRTY ? "Y" : "N",
+           p->p_pid);
 
        /* Kick off or invalidate the idle exit deferment if there's a state transition. */
        if (!(p->p_memstat_dirty & P_DIRTY_IS_DIRTY)) {
-               if (((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED) && 
-                       defer_now && !already_deferred) {
-                       
-                       /*
-                        * Request to defer a clean process that's idle-exit enabled 
-                        * and not already in the jetsam deferred band.
-                        */
-                       memorystatus_schedule_idle_demotion_locked(p, TRUE);
-                       reschedule = TRUE;
+               if ((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED) {
+                       if (defer_now && !already_deferred) {
+                               /*
+                                * Request to defer a clean process that's idle-exit enabled
+                                * and not already in the jetsam deferred band. Most likely a
+                                * new launch.
+                                */
+                               memorystatus_schedule_idle_demotion_locked(p, TRUE);
+                               reschedule = TRUE;
+                       } else if (!defer_now) {
+                               /*
+                                * The process isn't asking for the 'aging' facility.
+                                * Could be that it is:
+                                */
 
-               } else if (!defer_now && already_deferred) {
+                               if (already_deferred) {
+                                       /*
+                                        * already in the aging bands. Traditionally,
+                                        * some processes have tried to use this to
+                                        * opt out of the 'aging' facility.
+                                        */
 
-                       /*
-                        * Either the process is no longer idle-exit enabled OR
-                        * there's a request to cancel a currently active deferral.
-                        */
-                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
-                       reschedule = TRUE;
+                                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+                               } else {
+                                       /*
+                                        * agnostic to the 'aging' facility. In that case,
+                                        * we'll go ahead and opt it in because this is likely
+                                        * a new launch (clean process, dirty tracking enabled)
+                                        */
+
+                                       memorystatus_schedule_idle_demotion_locked(p, TRUE);
+                               }
+
+                               reschedule = TRUE;
+                       }
                }
        } else {
-
                /*
                 * We are trying to operate on a dirty process. Dirty processes have to
-                * be removed from the deferred band. The question is do we reset the 
+                * be removed from the deferred band. The question is do we reset the
                 * deferred state or not?
                 *
                 * This could be a legal request like:
-                * - this process had opted into the JETSAM_DEFERRED band
+                * - this process had opted into the 'aging' band
                 * - but it's now dirty and requests to opt out.
                 * In this case, we remove the process from the band and reset its
                 * state too. It'll opt back in properly when needed.
                 *
                 * OR, this request could be a user-space bug. E.g.:
-                * - this process had opted into the JETSAM_DEFERRED band when clean
+                * - this process had opted into the 'aging' band when clean
                 * - and, then issues another request to again put it into the band except
                 *   this time the process is dirty.
                 * The process going dirty, as a transition in memorystatus_dirty_set(), will pull the process out of
@@ -1934,34 +3279,37 @@ memorystatus_dirty_track(proc_t p, uint32_t pcontrol) {
                 * But we do it here anyways for coverage.
                 *
                 * memorystatus_update_idle_priority_locked()
-                * single-mindedly treats a dirty process as "cannot be in the deferred band".
+                * single-mindedly treats a dirty process as "cannot be in the aging band".
                 */
 
                if (!defer_now && already_deferred) {
                        memorystatus_invalidate_idle_demotion_locked(p, TRUE);
                        reschedule = TRUE;
                } else {
-                       memorystatus_invalidate_idle_demotion_locked(p, FALSE);
+                       boolean_t reset_state = (jetsam_aging_policy != kJetsamAgingPolicyLegacy) ? TRUE : FALSE;
+
+                       memorystatus_invalidate_idle_demotion_locked(p, reset_state);
                        reschedule = TRUE;
                }
        }
 
        memorystatus_update_idle_priority_locked(p);
-       
+
        if (reschedule) {
                memorystatus_reschedule_idle_demotion_locked();
        }
-               
+
        ret = 0;
-       
-exit:          
+
+exit:
        proc_list_unlock();
-       
+
        return ret;
 }
 
 int
-memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
+memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol)
+{
        int ret;
        boolean_t kill = false;
        boolean_t reschedule = FALSE;
@@ -1969,7 +3317,6 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
        boolean_t now_dirty = FALSE;
 
        MEMORYSTATUS_DEBUG(1, "memorystatus_dirty_set(): %d %d 0x%x 0x%x\n", self, p->p_pid, pcontrol, p->p_memstat_dirty);
-       
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DIRTY_SET), p->p_pid, self, pcontrol, 0, 0);
 
        proc_list_lock();
@@ -1987,18 +3334,19 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
                goto exit;
        }
 
-       if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY)
+       if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY) {
                was_dirty = TRUE;
+       }
 
        if (!(p->p_memstat_dirty & P_DIRTY_TRACK)) {
                /* Dirty tracking not enabled */
-               ret = EINVAL;                   
+               ret = EINVAL;
        } else if (pcontrol && (p->p_memstat_dirty & P_DIRTY_TERMINATED)) {
-               /* 
+               /*
                 * Process is set to be terminated and we're attempting to mark it dirty.
                 * Set for termination and marking as clean is OK - see <rdar://problem/10594349>.
                 */
-               ret = EBUSY;            
+               ret = EBUSY;
        } else {
                int flag = (self == TRUE) ? P_DIRTY : P_DIRTY_SHUTDOWN;
                if (pcontrol && !(p->p_memstat_dirty & flag)) {
@@ -2013,7 +3361,7 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
                                kill = true;
                        } else if ((flag == P_DIRTY) && (p->p_memstat_dirty & P_DIRTY_TERMINATED)) {
                                /* Kill previously terminated processes if set clean */
-                               kill = true;                                            
+                               kill = true;
                        }
                        p->p_memstat_dirty &= ~flag;
                        memorystatus_dirty_count--;
@@ -2028,69 +3376,77 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
                goto exit;
        }
 
-       if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY)
+       if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY) {
                now_dirty = TRUE;
+       }
 
        if ((was_dirty == TRUE && now_dirty == FALSE) ||
            (was_dirty == FALSE && now_dirty == TRUE)) {
-
                /* Manage idle exit deferral, if applied */
-               if ((p->p_memstat_dirty & (P_DIRTY_IDLE_EXIT_ENABLED|P_DIRTY_DEFER_IN_PROGRESS)) ==
-                   (P_DIRTY_IDLE_EXIT_ENABLED|P_DIRTY_DEFER_IN_PROGRESS)) {
-
+               if ((p->p_memstat_dirty & P_DIRTY_IDLE_EXIT_ENABLED) == P_DIRTY_IDLE_EXIT_ENABLED) {
                        /*
-                        * P_DIRTY_DEFER_IN_PROGRESS means the process is in the deferred band OR it might be heading back
-                        * there once it's clean again and has some protection window left.
+                        * Legacy mode: P_DIRTY_AGING_IN_PROGRESS means the process is in the aging band OR it might be heading back
+                        * there once it's clean again. For the legacy case, this only applies if it has some protection window left.
+                        * P_DIRTY_DEFER: one-time protection window given at launch
+                        * P_DIRTY_DEFER_ALWAYS: protection window given for every dirty->clean transition. Like non-legacy mode.
+                        *
+                        * Non-Legacy mode: P_DIRTY_AGING_IN_PROGRESS means the process is in the aging band. It will always stop over
+                        * in that band on it's way to IDLE.
                         */
 
                        if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY) {
                                /*
                                 * New dirty process i.e. "was_dirty == FALSE && now_dirty == TRUE"
                                 *
-                                * The process will move from the deferred band to its higher requested
-                                * jetsam band. But we don't clear its state i.e. we want to remember that
-                                * this process was part of the "deferred" band and will return to it.
-                                *
-                                * This way, we don't let it age beyond the protection
-                                * window when it returns to "clean". All the while giving
-                                * it a chance to perform its work while "dirty".
-                                *
+                                * The process will move from its aging band to its higher requested
+                                * jetsam band.
                                 */
-                               memorystatus_invalidate_idle_demotion_locked(p, FALSE);
+                               boolean_t reset_state = (jetsam_aging_policy != kJetsamAgingPolicyLegacy) ? TRUE : FALSE;
+
+                               memorystatus_invalidate_idle_demotion_locked(p, reset_state);
                                reschedule = TRUE;
                        } else {
-
                                /*
                                 * Process is back from "dirty" to "clean".
-                                * 
-                                * Is its timer up OR does it still have some protection
-                                * window left?
                                 */
 
-                               if (mach_absolute_time() >= p->p_memstat_idledeadline) {
-                                       /*
-                                        * The process' deadline has expired. It currently
-                                        * does not reside in the DEFERRED bucket.
-                                        * 
-                                        * It's on its way to the JETSAM_PRIORITY_IDLE 
-                                        * bucket via memorystatus_update_idle_priority_locked()
-                                        * below.
-                                        
-                                        * So all we need to do is reset all the state on the
-                                        * process that's related to the DEFERRED bucket i.e.
-                                        * the DIRTY_DEFER_IN_PROGRESS flag and the timer deadline.
-                                        *
-                                        */
+                               if (jetsam_aging_policy == kJetsamAgingPolicyLegacy) {
+                                       if (((p->p_memstat_dirty & P_DIRTY_DEFER_ALWAYS) == FALSE) &&
+                                           (mach_absolute_time() >= p->p_memstat_idledeadline)) {
+                                               /*
+                                                * The process' hasn't enrolled in the "always defer after dirty"
+                                                * mode and its deadline has expired. It currently
+                                                * does not reside in any of the aging buckets.
+                                                *
+                                                * It's on its way to the JETSAM_PRIORITY_IDLE
+                                                * bucket via memorystatus_update_idle_priority_locked()
+                                                * below.
+                                                *
+                                                * So all we need to do is reset all the state on the
+                                                * process that's related to the aging bucket i.e.
+                                                * the AGING_IN_PROGRESS flag and the timer deadline.
+                                                */
 
-                                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
-                                       reschedule = TRUE;
+                                               memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+                                               reschedule = TRUE;
+                                       } else {
+                                               /*
+                                                * Process enrolled in "always stop in deferral band after dirty" OR
+                                                * it still has some protection window left and so
+                                                * we just re-arm the timer without modifying any
+                                                * state on the process iff it still wants into that band.
+                                                */
+
+                                               if (p->p_memstat_dirty & P_DIRTY_DEFER_ALWAYS) {
+                                                       memorystatus_schedule_idle_demotion_locked(p, TRUE);
+                                                       reschedule = TRUE;
+                                               } else if (p->p_memstat_dirty & P_DIRTY_AGING_IN_PROGRESS) {
+                                                       memorystatus_schedule_idle_demotion_locked(p, FALSE);
+                                                       reschedule = TRUE;
+                                               }
+                                       }
                                } else {
-                                       /*
-                                        * It still has some protection window left and so
-                                        * we just re-arm the timer without modifying any
-                                        * state on the process.
-                                        */
-                                       memorystatus_schedule_idle_demotion_locked(p, FALSE);
+                                       memorystatus_schedule_idle_demotion_locked(p, TRUE);
                                        reschedule = TRUE;
                                }
                        }
@@ -2098,24 +3454,39 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
 
                memorystatus_update_idle_priority_locked(p);
 
-#if CONFIG_JETSAM
                if (memorystatus_highwater_enabled) {
-                       boolean_t trigger_exception;
-                       /* 
-                        * We are in this path because this process transitioned between 
+                       boolean_t ledger_update_needed = TRUE;
+                       boolean_t use_active;
+                       boolean_t is_fatal;
+                       /*
+                        * We are in this path because this process transitioned between
                         * dirty <--> clean state.  Update the cached memory limits.
                         */
 
                        if (proc_jetsam_state_is_active_locked(p) == TRUE) {
                                /*
+                                * process is pinned in elevated band
+                                * or
                                 * process is dirty
                                 */
-                               CACHE_ACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                               CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal);
+                               use_active = TRUE;
+                               ledger_update_needed = TRUE;
                        } else {
                                /*
-                                * process is clean
+                                * process is clean...but if it has opted into pressured-exit
+                                * we don't apply the INACTIVE limit till the process has aged
+                                * out and is entering the IDLE band.
+                                * See memorystatus_update_priority_locked() for that.
                                 */
-                               CACHE_INACTIVE_LIMITS_LOCKED(p, trigger_exception);
+
+                               if (p->p_memstat_dirty & P_DIRTY_ALLOW_IDLE_EXIT) {
+                                       ledger_update_needed = FALSE;
+                               } else {
+                                       CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal);
+                                       use_active = FALSE;
+                                       ledger_update_needed = TRUE;
+                               }
                        }
 
                        /*
@@ -2127,7 +3498,7 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
                         * See rdar://21394491.
                         */
 
-                       if (proc_ref_locked(p) == p) {
+                       if (ledger_update_needed && proc_ref_locked(p) == p) {
                                int ledger_limit;
                                if (p->p_memstat_memlimit > 0) {
                                        ledger_limit = p->p_memstat_memlimit;
@@ -2135,19 +3506,17 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
                                        ledger_limit = -1;
                                }
                                proc_list_unlock();
-                               task_set_phys_footprint_limit_internal(p->task, ledger_limit, NULL, trigger_exception);
+                               task_set_phys_footprint_limit_internal(p->task, ledger_limit, NULL, use_active, is_fatal);
                                proc_list_lock();
                                proc_rele_locked(p);
 
                                MEMORYSTATUS_DEBUG(3, "memorystatus_dirty_set: new limit on pid %d (%dMB %s) priority(%d) dirty?=0x%x %s\n",
-                                          p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
-                                          (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), p->p_memstat_effectivepriority, p->p_memstat_dirty,
-                                          (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
+                                   p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
+                                   (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), p->p_memstat_effectivepriority, p->p_memstat_dirty,
+                                   (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
                        }
-
                }
-#endif /* CONFIG_JETSAM */
-       
+
                /* If the deferral state changed, reschedule the demotion timer */
                if (reschedule) {
                        memorystatus_reschedule_idle_demotion_locked();
@@ -2162,7 +3531,7 @@ memorystatus_dirty_set(proc_t p, boolean_t self, uint32_t pcontrol) {
                        proc_rele_locked(p);
                }
        }
-       
+
 exit:
        proc_list_unlock();
 
@@ -2170,12 +3539,12 @@ exit:
 }
 
 int
-memorystatus_dirty_clear(proc_t p, uint32_t pcontrol) {
-
+memorystatus_dirty_clear(proc_t p, uint32_t pcontrol)
+{
        int ret = 0;
 
        MEMORYSTATUS_DEBUG(1, "memorystatus_dirty_clear(): %d 0x%x 0x%x\n", p->p_pid, pcontrol, p->p_memstat_dirty);
-       
+
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_DIRTY_CLEAR), p->p_pid, pcontrol, 0, 0, 0);
 
        proc_list_lock();
@@ -2195,11 +3564,11 @@ memorystatus_dirty_clear(proc_t p, uint32_t pcontrol) {
 
        if (!(p->p_memstat_dirty & P_DIRTY_TRACK)) {
                /* Dirty tracking not enabled */
-               ret = EINVAL;                   
+               ret = EINVAL;
                goto exit;
-       } 
+       }
 
-       if (!pcontrol || (pcontrol & (PROC_DIRTY_LAUNCH_IN_PROGRESS | PROC_DIRTY_DEFER)) == 0) {
+       if (!pcontrol || (pcontrol & (PROC_DIRTY_LAUNCH_IN_PROGRESS | PROC_DIRTY_DEFER | PROC_DIRTY_DEFER_ALWAYS)) == 0) {
                ret = EINVAL;
                goto exit;
        }
@@ -2209,16 +3578,18 @@ memorystatus_dirty_clear(proc_t p, uint32_t pcontrol) {
        }
 
        /* This can be set and cleared exactly once. */
-       if (pcontrol & PROC_DIRTY_DEFER) {
-
-               if (p->p_memstat_dirty & P_DIRTY_DEFER) {
-
-                       p->p_memstat_dirty &= ~P_DIRTY_DEFER;
+       if (pcontrol & (PROC_DIRTY_DEFER | PROC_DIRTY_DEFER_ALWAYS)) {
+               if (p->p_memstat_dirty & P_DIRTY_DEFER) {
+                       p->p_memstat_dirty &= ~(P_DIRTY_DEFER);
+               }
 
-                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
-                       memorystatus_update_idle_priority_locked(p);
-                       memorystatus_reschedule_idle_demotion_locked();
+               if (p->p_memstat_dirty & P_DIRTY_DEFER_ALWAYS) {
+                       p->p_memstat_dirty &= ~(P_DIRTY_DEFER_ALWAYS);
                }
+
+               memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+               memorystatus_update_idle_priority_locked(p);
+               memorystatus_reschedule_idle_demotion_locked();
        }
 
        ret = 0;
@@ -2229,11 +3600,12 @@ exit:
 }
 
 int
-memorystatus_dirty_get(proc_t p) {
+memorystatus_dirty_get(proc_t p)
+{
        int ret = 0;
-    
+
        proc_list_lock();
-       
+
        if (p->p_memstat_dirty & P_DIRTY_TRACK) {
                ret |= PROC_DIRTY_TRACKED;
                if (p->p_memstat_dirty & P_DIRTY_ALLOW_IDLE_EXIT) {
@@ -2246,21 +3618,22 @@ memorystatus_dirty_get(proc_t p) {
                        ret |= PROC_DIRTY_LAUNCH_IS_IN_PROGRESS;
                }
        }
-       
+
        proc_list_unlock();
-    
+
        return ret;
 }
 
 int
-memorystatus_on_terminate(proc_t p) {
+memorystatus_on_terminate(proc_t p)
+{
        int sig;
-    
+
        proc_list_lock();
-       
+
        p->p_memstat_dirty |= P_DIRTY_TERMINATED;
-       
-       if ((p->p_memstat_dirty & (P_DIRTY_TRACK|P_DIRTY_IS_DIRTY)) == P_DIRTY_TRACK) {
+
+       if ((p->p_memstat_dirty & (P_DIRTY_TRACK | P_DIRTY_IS_DIRTY)) == P_DIRTY_TRACK) {
                /* Clean; mark as terminated and issue SIGKILL */
                sig = SIGKILL;
        } else {
@@ -2269,7 +3642,7 @@ memorystatus_on_terminate(proc_t p) {
        }
 
        proc_list_unlock();
-       
+
        return sig;
 }
 
@@ -2278,12 +3651,10 @@ memorystatus_on_suspend(proc_t p)
 {
 #if CONFIG_FREEZE
        uint32_t pages;
-       memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL, NULL);
+       memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL);
 #endif
        proc_list_lock();
 #if CONFIG_FREEZE
-       p->p_memstat_suspendedfootprint = pages;
-       memorystatus_suspended_footprint_total += pages;
        memorystatus_suspended_count++;
 #endif
        p->p_memstat_state |= P_MEMSTAT_SUSPENDED;
@@ -2303,20 +3674,39 @@ memorystatus_on_resume(proc_t p)
 #if CONFIG_FREEZE
        frozen = (p->p_memstat_state & P_MEMSTAT_FROZEN);
        if (frozen) {
-               memorystatus_frozen_count--;
-               p->p_memstat_state |= P_MEMSTAT_PRIOR_THAW;
+               /*
+                * Now that we don't _thaw_ a process completely,
+                * resuming it (and having some on-demand swapins)
+                * shouldn't preclude it from being counted as frozen.
+                *
+                * memorystatus_frozen_count--;
+                *
+                * We preserve the P_MEMSTAT_FROZEN state since the process
+                * could have state on disk AND so will deserve some protection
+                * in the jetsam bands.
+                */
+               if ((p->p_memstat_state & P_MEMSTAT_REFREEZE_ELIGIBLE) == 0) {
+                       p->p_memstat_state |= P_MEMSTAT_REFREEZE_ELIGIBLE;
+                       memorystatus_refreeze_eligible_count++;
+               }
+               p->p_memstat_thaw_count++;
+
+               memorystatus_thaw_count++;
        }
 
-       memorystatus_suspended_footprint_total -= p->p_memstat_suspendedfootprint;
        memorystatus_suspended_count--;
-       
+
        pid = p->p_pid;
 #endif
 
-       p->p_memstat_state &= ~(P_MEMSTAT_SUSPENDED | P_MEMSTAT_FROZEN);
+       /*
+        * P_MEMSTAT_FROZEN will remain unchanged. This used to be:
+        * p->p_memstat_state &= ~(P_MEMSTAT_SUSPENDED | P_MEMSTAT_FROZEN);
+        */
+       p->p_memstat_state &= ~P_MEMSTAT_SUSPENDED;
 
        proc_list_unlock();
-    
+
 #if CONFIG_FREEZE
        if (frozen) {
                memorystatus_freeze_entry_t data = { pid, FALSE, 0 };
@@ -2332,13 +3722,17 @@ memorystatus_on_inactivity(proc_t p)
 #if CONFIG_FREEZE
        /* Wake the freeze thread */
        thread_wakeup((event_t)&memorystatus_freeze_wakeup);
-#endif 
+#endif
 }
 
+/*
+ * The proc_list_lock is held by the caller.
+ */
 static uint32_t
-memorystatus_build_state(proc_t p) {
+memorystatus_build_state(proc_t p)
+{
        uint32_t snapshot_state = 0;
-    
+
        /* General */
        if (p->p_memstat_state & P_MEMSTAT_SUSPENDED) {
                snapshot_state |= kMemorystatusSuspended;
@@ -2346,10 +3740,10 @@ memorystatus_build_state(proc_t p) {
        if (p->p_memstat_state & P_MEMSTAT_FROZEN) {
                snapshot_state |= kMemorystatusFrozen;
        }
-       if (p->p_memstat_state & P_MEMSTAT_PRIOR_THAW) {
-               snapshot_state |= kMemorystatusWasThawed;
+       if (p->p_memstat_state & P_MEMSTAT_REFREEZE_ELIGIBLE) {
+               snapshot_state |= kMemorystatusWasThawed;
        }
-       
+
        /* Tracking */
        if (p->p_memstat_dirty & P_DIRTY_TRACK) {
                snapshot_state |= kMemorystatusTracked;
@@ -2364,8 +3758,6 @@ memorystatus_build_state(proc_t p) {
        return snapshot_state;
 }
 
-#if !CONFIG_JETSAM
-
 static boolean_t
 kill_idle_exit_proc(void)
 {
@@ -2373,47 +3765,80 @@ kill_idle_exit_proc(void)
        uint64_t current_time;
        boolean_t killed = FALSE;
        unsigned int i = 0;
+       os_reason_t jetsam_reason = OS_REASON_NULL;
 
        /* Pick next idle exit victim. */
        current_time = mach_absolute_time();
-       
+
+       jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_IDLE_EXIT);
+       if (jetsam_reason == OS_REASON_NULL) {
+               printf("kill_idle_exit_proc: failed to allocate jetsam reason\n");
+       }
+
        proc_list_lock();
-       
+
        p = memorystatus_get_first_proc_locked(&i, FALSE);
        while (p) {
                /* No need to look beyond the idle band */
                if (p->p_memstat_effectivepriority != JETSAM_PRIORITY_IDLE) {
                        break;
                }
-               
-               if ((p->p_memstat_dirty & (P_DIRTY_ALLOW_IDLE_EXIT|P_DIRTY_IS_DIRTY|P_DIRTY_TERMINATED)) == (P_DIRTY_ALLOW_IDLE_EXIT)) {                                
+
+               if ((p->p_memstat_dirty & (P_DIRTY_ALLOW_IDLE_EXIT | P_DIRTY_IS_DIRTY | P_DIRTY_TERMINATED)) == (P_DIRTY_ALLOW_IDLE_EXIT)) {
                        if (current_time >= p->p_memstat_idledeadline) {
                                p->p_memstat_dirty |= P_DIRTY_TERMINATED;
                                victim_p = proc_ref_locked(p);
                                break;
                        }
                }
-               
+
                p = memorystatus_get_next_proc_locked(&i, p, FALSE);
        }
-       
+
        proc_list_unlock();
-       
+
        if (victim_p) {
-               printf("memorystatus_thread: idle exiting pid %d [%s]\n", victim_p->p_pid, (victim_p->p_comm ? victim_p->p_comm : "(unknown)"));
-               killed = memorystatus_do_kill(victim_p, kMemorystatusKilledIdleExit);
+               printf("memorystatus: killing_idle_process pid %d [%s]\n", victim_p->p_pid, (*victim_p->p_name ? victim_p->p_name : "unknown"));
+               killed = memorystatus_do_kill(victim_p, kMemorystatusKilledIdleExit, jetsam_reason);
                proc_rele(victim_p);
+       } else {
+               os_reason_free(jetsam_reason);
        }
 
        return killed;
 }
-#endif
+
+static void
+memorystatus_thread_wake(void)
+{
+       int thr_id = 0;
+       int active_thr = atomic_load(&active_jetsam_threads);
+
+       /* Wakeup all the jetsam threads */
+       for (thr_id = 0; thr_id < active_thr; thr_id++) {
+               thread_wakeup((event_t)&jetsam_threads[thr_id].memorystatus_wakeup);
+       }
+}
 
 #if CONFIG_JETSAM
+
 static void
-memorystatus_thread_wake(void) {
-       thread_wakeup((event_t)&memorystatus_wakeup);
+memorystatus_thread_pool_max()
+{
+       /* Increase the jetsam thread pool to max_jetsam_threads */
+       int max_threads = max_jetsam_threads;
+       printf("Expanding memorystatus pool to %d!\n", max_threads);
+       atomic_store(&active_jetsam_threads, max_threads);
+}
+
+static void
+memorystatus_thread_pool_default()
+{
+       /* Restore the jetsam thread pool to a single thread */
+       printf("Reverting memorystatus pool back to 1\n");
+       atomic_store(&active_jetsam_threads, 1);
 }
+
 #endif /* CONFIG_JETSAM */
 
 extern void vm_pressure_response(void);
@@ -2421,201 +3846,605 @@ extern void vm_pressure_response(void);
 static int
 memorystatus_thread_block(uint32_t interval_ms, thread_continue_t continuation)
 {
+       struct jetsam_thread_state *jetsam_thread = jetsam_current_thread();
+
        if (interval_ms) {
-               assert_wait_timeout(&memorystatus_wakeup, THREAD_UNINT, interval_ms, 1000 * NSEC_PER_USEC);
+               assert_wait_timeout(&jetsam_thread->memorystatus_wakeup, THREAD_UNINT, interval_ms, NSEC_PER_MSEC);
        } else {
-               assert_wait(&memorystatus_wakeup, THREAD_UNINT);
+               assert_wait(&jetsam_thread->memorystatus_wakeup, THREAD_UNINT);
        }
-       
-       return thread_block(continuation);   
+
+       return thread_block(continuation);
 }
 
-static void
-memorystatus_thread(void *param __unused, wait_result_t wr __unused)
+static boolean_t
+memorystatus_avail_pages_below_pressure(void)
 {
-       static boolean_t is_vm_privileged = FALSE;
+#if CONFIG_EMBEDDED
+/*
+ * Instead of CONFIG_EMBEDDED for these *avail_pages* routines, we should
+ * key off of the system having dynamic swap support. With full swap support,
+ * the system shouldn't really need to worry about various page thresholds.
+ */
+       return memorystatus_available_pages <= memorystatus_available_pages_pressure;
+#else /* CONFIG_EMBEDDED */
+       return FALSE;
+#endif /* CONFIG_EMBEDDED */
+}
 
-#if CONFIG_JETSAM
-       boolean_t post_snapshot = FALSE;
-       uint32_t errors = 0;
-       uint32_t hwm_kill = 0;
-       boolean_t sort_flag = TRUE;
+static boolean_t
+memorystatus_avail_pages_below_critical(void)
+{
+#if CONFIG_EMBEDDED
+       return memorystatus_available_pages <= memorystatus_available_pages_critical;
+#else /* CONFIG_EMBEDDED */
+       return FALSE;
+#endif /* CONFIG_EMBEDDED */
+}
+
+static boolean_t
+memorystatus_post_snapshot(int32_t priority, uint32_t cause)
+{
+#if CONFIG_EMBEDDED
+#pragma unused(cause)
+       /*
+        * Don't generate logs for steady-state idle-exit kills,
+        * unless it is overridden for debug or by the device
+        * tree.
+        */
+
+       return (priority != JETSAM_PRIORITY_IDLE) || memorystatus_idle_snapshot;
+
+#else /* CONFIG_EMBEDDED */
+       /*
+        * Don't generate logs for steady-state idle-exit kills,
+        * unless
+        * - it is overridden for debug or by the device
+        * tree.
+        * OR
+        * - the kill causes are important i.e. not kMemorystatusKilledIdleExit
+        */
+
+       boolean_t snapshot_eligible_kill_cause = (is_reason_thrashing(cause) || is_reason_zone_map_exhaustion(cause));
+       return (priority != JETSAM_PRIORITY_IDLE) || memorystatus_idle_snapshot || snapshot_eligible_kill_cause;
+#endif /* CONFIG_EMBEDDED */
+}
+
+static boolean_t
+memorystatus_action_needed(void)
+{
+#if CONFIG_EMBEDDED
+       return is_reason_thrashing(kill_under_pressure_cause) ||
+              is_reason_zone_map_exhaustion(kill_under_pressure_cause) ||
+              memorystatus_available_pages <= memorystatus_available_pages_pressure;
+#else /* CONFIG_EMBEDDED */
+       return is_reason_thrashing(kill_under_pressure_cause) ||
+              is_reason_zone_map_exhaustion(kill_under_pressure_cause);
+#endif /* CONFIG_EMBEDDED */
+}
 
-        /* Jetsam Loop Detection - locals */
+#if CONFIG_FREEZE
+extern void             vm_swap_consider_defragmenting(int);
+
+/*
+ * This routine will _jetsam_ all frozen processes
+ * and reclaim the swap space immediately.
+ *
+ * So freeze has to be DISABLED when we call this routine.
+ */
+
+void
+memorystatus_disable_freeze(void)
+{
        memstat_bucket_t *bucket;
-       int             jld_bucket_count = 0;
-       struct timeval  jld_now_tstamp = {0,0};
-       uint64_t        jld_now_msecs = 0;
-
-       /* Jetsam Loop Detection - statics */
-       static uint64_t  jld_timestamp_msecs = 0;
-       static int       jld_idle_kill_candidates = 0;  /* Number of available processes in band 0,1 at start */
-       static int       jld_idle_kills = 0;            /* Number of procs killed during eval period  */
-       static int       jld_eval_aggressive_count = 0;         /* Bumps the max priority in aggressive loop */
-       static int32_t   jld_priority_band_max = JETSAM_PRIORITY_UI_SUPPORT;
-#endif
+       int bucket_count = 0, retries = 0;
+       boolean_t retval = FALSE, killed = FALSE;
+       uint32_t errors = 0, errors_over_prev_iteration = 0;
+       os_reason_t jetsam_reason = 0;
+       unsigned int band = 0;
+       proc_t p = PROC_NULL, next_p = PROC_NULL;
 
-       if (is_vm_privileged == FALSE) {
-               /* 
-                * It's the first time the thread has run, so just mark the thread as privileged and block.
-                * This avoids a spurious pass with unset variables, as set out in <rdar://problem/9609402>.
-                */
-               thread_wire(host_priv_self(), current_thread(), TRUE);
-               is_vm_privileged = TRUE;
-               
-               if (vm_restricted_to_single_processor == TRUE)
-                       thread_vm_bind_group_add();
+       assert(memorystatus_freeze_enabled == FALSE);
 
-               memorystatus_thread_block(0, memorystatus_thread);
+       jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_DISK_SPACE_SHORTAGE);
+       if (jetsam_reason == OS_REASON_NULL) {
+               printf("memorystatus_disable_freeze: failed to allocate jetsam reason\n");
        }
-       
-#if CONFIG_JETSAM
-       
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_SCAN) | DBG_FUNC_START,
-                             memorystatus_available_pages, memorystatus_jld_enabled, memorystatus_jld_eval_period_msecs, memorystatus_jld_eval_aggressive_count,0);
 
        /*
-        * Jetsam aware version.
-        *
-        * The VM pressure notification thread is working it's way through clients in parallel.
+        * Let's relocate all frozen processes into band 8. Demoted frozen processes
+        * are sitting in band 0 currently and it's possible to have a frozen process
+        * in the FG band being actively used. We don't reset its frozen state when
+        * it is resumed because it has state on disk.
         *
-        * So, while the pressure notification thread is targeting processes in order of 
-        * increasing jetsam priority, we can hopefully reduce / stop it's work by killing 
-        * any processes that have exceeded their highwater mark.
+        * We choose to do this relocation rather than implement a new 'kill frozen'
+        * process function for these reasons:
+        * - duplication of code: too many kill functions exist and we need to rework them better.
+        * - disk-space-shortage kills are rare
+        * - not having the 'real' jetsam band at time of the this frozen kill won't preclude us
+        *   from answering any imp. questions re. jetsam policy/effectiveness.
         *
-        * If we run out of HWM processes and our available pages drops below the critical threshold, then,
-        * we target the least recently used process in order of increasing jetsam priority (exception: the FG band).
+        * This is essentially what memorystatus_update_inactive_jetsam_priority_band() does while
+        * avoiding the application of memory limits.
         */
-       while (is_thrashing(kill_under_pressure_cause) ||
-              memorystatus_available_pages <= memorystatus_available_pages_pressure) {
-               boolean_t killed;
-               int32_t priority;
-               uint32_t cause;
 
-               if (kill_under_pressure_cause) {
-                       cause = kill_under_pressure_cause;
-               } else {
-                       cause = kMemorystatusKilledVMPageShortage;
-               }
+again:
+       proc_list_lock();
 
-#if LEGACY_HIWATER
-               /* Highwater */
-               killed = memorystatus_kill_hiwat_proc(&errors);
-               if (killed) {
-                       hwm_kill++;
-                       post_snapshot = TRUE;
-                       goto done;
-               } else {
-                       memorystatus_hwm_candidates = FALSE;
+       band = JETSAM_PRIORITY_IDLE;
+       p = PROC_NULL;
+       next_p = PROC_NULL;
+
+       next_p = memorystatus_get_first_proc_locked(&band, TRUE);
+       while (next_p) {
+               p = next_p;
+               next_p = memorystatus_get_next_proc_locked(&band, p, TRUE);
+
+               if (p->p_memstat_effectivepriority > JETSAM_PRIORITY_FOREGROUND) {
+                       break;
                }
 
-               /* No highwater processes to kill. Continue or stop for now? */
-               if (!is_thrashing(kill_under_pressure_cause) &&
-                   (memorystatus_available_pages > memorystatus_available_pages_critical)) {
+               if ((p->p_memstat_state & P_MEMSTAT_FROZEN) == FALSE) {
+                       continue;
+               }
+
+               if (p->p_memstat_state & P_MEMSTAT_ERROR) {
+                       p->p_memstat_state &= ~P_MEMSTAT_ERROR;
+               }
+
+               if (p->p_memstat_effectivepriority == memorystatus_freeze_jetsam_band) {
+                       continue;
+               }
+
+               /*
+                * We explicitly add this flag here so the process looks like a normal
+                * frozen process i.e. P_MEMSTAT_FROZEN and P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND.
+                * We don't bother with assigning the 'active' memory
+                * limits at this point because we are going to be killing it soon below.
+                */
+               p->p_memstat_state |= P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND;
+               memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+
+               memorystatus_update_priority_locked(p, memorystatus_freeze_jetsam_band, FALSE, TRUE);
+       }
+
+       bucket = &memstat_bucket[memorystatus_freeze_jetsam_band];
+       bucket_count = bucket->count;
+       proc_list_unlock();
+
+       /*
+        * Bucket count is already stale at this point. But, we don't expect
+        * freezing to continue since we have already disabled the freeze functionality.
+        * However, an existing freeze might be in progress. So we might miss that process
+        * in the first go-around. We hope to catch it in the next.
+        */
+
+       errors_over_prev_iteration = 0;
+       while (bucket_count) {
+               bucket_count--;
+
+               /*
+                * memorystatus_kill_elevated_process() drops a reference,
+                * so take another one so we can continue to use this exit reason
+                * even after it returns.
+                */
+
+               os_reason_ref(jetsam_reason);
+               retval = memorystatus_kill_elevated_process(
+                       kMemorystatusKilledDiskSpaceShortage,
+                       jetsam_reason,
+                       memorystatus_freeze_jetsam_band,
+                       0, /* the iteration of aggressive jetsam..ignored here */
+                       &errors);
+
+               if (errors > 0) {
+                       printf("memorystatus_disable_freeze: memorystatus_kill_elevated_process returned %d error(s)\n", errors);
+                       errors_over_prev_iteration += errors;
+                       errors = 0;
+               }
+
+               if (retval == 0) {
                        /*
-                        * We are _not_ out of pressure but we are above the critical threshold and there's:
-                        * - no compressor thrashing
-                        * - no more HWM processes left.
-                        * For now, don't kill any other processes.
+                        * No frozen processes left to kill.
                         */
-               
-                       if (hwm_kill == 0) {
-                               memorystatus_thread_wasted_wakeup++;
+                       break;
+               }
+
+               killed = TRUE;
+       }
+
+       proc_list_lock();
+
+       if (memorystatus_frozen_count) {
+               /*
+                * A frozen process snuck in and so
+                * go back around to kill it. That
+                * process may have been resumed and
+                * put into the FG band too. So we
+                * have to do the relocation again.
+                */
+               assert(memorystatus_freeze_enabled == FALSE);
+
+               retries++;
+               if (retries < 3) {
+                       proc_list_unlock();
+                       goto again;
+               }
+#if DEVELOPMENT || DEBUG
+               panic("memorystatus_disable_freeze: Failed to kill all frozen processes, memorystatus_frozen_count = %d, errors = %d",
+                   memorystatus_frozen_count, errors_over_prev_iteration);
+#endif /* DEVELOPMENT || DEBUG */
+       }
+       proc_list_unlock();
+
+       os_reason_free(jetsam_reason);
+
+       if (killed) {
+               vm_swap_consider_defragmenting(VM_SWAP_FLAGS_FORCE_DEFRAG | VM_SWAP_FLAGS_FORCE_RECLAIM);
+
+               proc_list_lock();
+               size_t snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) +
+                   sizeof(memorystatus_jetsam_snapshot_entry_t) * (memorystatus_jetsam_snapshot_count);
+               uint64_t timestamp_now = mach_absolute_time();
+               memorystatus_jetsam_snapshot->notification_time = timestamp_now;
+               memorystatus_jetsam_snapshot->js_gencount++;
+               if (memorystatus_jetsam_snapshot_count > 0 && (memorystatus_jetsam_snapshot_last_timestamp == 0 ||
+                   timestamp_now > memorystatus_jetsam_snapshot_last_timestamp + memorystatus_jetsam_snapshot_timeout)) {
+                       proc_list_unlock();
+                       int ret = memorystatus_send_note(kMemorystatusSnapshotNote, &snapshot_size, sizeof(snapshot_size));
+                       if (!ret) {
+                               proc_list_lock();
+                               memorystatus_jetsam_snapshot_last_timestamp = timestamp_now;
+                               proc_list_unlock();
                        }
+               } else {
+                       proc_list_unlock();
+               }
+       }
 
-                       break;
+       return;
+}
+#endif /* CONFIG_FREEZE */
+
+static boolean_t
+memorystatus_act_on_hiwat_processes(uint32_t *errors, uint32_t *hwm_kill, boolean_t *post_snapshot, __unused boolean_t *is_critical)
+{
+       boolean_t purged = FALSE;
+       boolean_t killed = memorystatus_kill_hiwat_proc(errors, &purged);
+
+       if (killed) {
+               *hwm_kill = *hwm_kill + 1;
+               *post_snapshot = TRUE;
+               return TRUE;
+       } else {
+               if (purged == FALSE) {
+                       /* couldn't purge and couldn't kill */
+                       memorystatus_hwm_candidates = FALSE;
                }
-#endif
-               if (memorystatus_jld_enabled == TRUE) {
+       }
 
-                       /*
-                        * Jetsam Loop Detection: attempt to detect
-                        * rapid daemon relaunches in the lower bands.
-                        */
-                       
-                       microuptime(&jld_now_tstamp);
+#if CONFIG_JETSAM
+       /* No highwater processes to kill. Continue or stop for now? */
+       if (!is_reason_thrashing(kill_under_pressure_cause) &&
+           !is_reason_zone_map_exhaustion(kill_under_pressure_cause) &&
+           (memorystatus_available_pages > memorystatus_available_pages_critical)) {
+               /*
+                * We are _not_ out of pressure but we are above the critical threshold and there's:
+                * - no compressor thrashing
+                * - enough zone memory
+                * - no more HWM processes left.
+                * For now, don't kill any other processes.
+                */
 
-                       /*
-                        * Ignore usecs in this calculation.
-                        * msecs granularity is close enough.
-                        */
-                       jld_now_msecs = (jld_now_tstamp.tv_sec * 1000);
+               if (*hwm_kill == 0) {
+                       memorystatus_thread_wasted_wakeup++;
+               }
 
-                       proc_list_lock();
+               *is_critical = FALSE;
+
+               return TRUE;
+       }
+#endif /* CONFIG_JETSAM */
+
+       return FALSE;
+}
+
+static boolean_t
+memorystatus_act_aggressive(uint32_t cause, os_reason_t jetsam_reason, int *jld_idle_kills, boolean_t *corpse_list_purged, boolean_t *post_snapshot)
+{
+       if (memorystatus_jld_enabled == TRUE) {
+               boolean_t killed;
+               uint32_t errors = 0;
+
+               /* Jetsam Loop Detection - locals */
+               memstat_bucket_t *bucket;
+               int             jld_bucket_count = 0;
+               struct timeval  jld_now_tstamp = {0, 0};
+               uint64_t        jld_now_msecs = 0;
+               int             elevated_bucket_count = 0;
+
+               /* Jetsam Loop Detection - statics */
+               static uint64_t  jld_timestamp_msecs = 0;
+               static int       jld_idle_kill_candidates = 0;  /* Number of available processes in band 0,1 at start */
+               static int       jld_eval_aggressive_count = 0;         /* Bumps the max priority in aggressive loop */
+               static int32_t   jld_priority_band_max = JETSAM_PRIORITY_UI_SUPPORT;
+               /*
+                * Jetsam Loop Detection: attempt to detect
+                * rapid daemon relaunches in the lower bands.
+                */
+
+               microuptime(&jld_now_tstamp);
+
+               /*
+                * Ignore usecs in this calculation.
+                * msecs granularity is close enough.
+                */
+               jld_now_msecs = (jld_now_tstamp.tv_sec * 1000);
+
+               proc_list_lock();
+               switch (jetsam_aging_policy) {
+               case kJetsamAgingPolicyLegacy:
                        bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
                        jld_bucket_count = bucket->count;
-                       bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE_DEFERRED];
+                       bucket = &memstat_bucket[JETSAM_PRIORITY_AGING_BAND1];
                        jld_bucket_count += bucket->count;
-                       proc_list_unlock();
+                       break;
+               case kJetsamAgingPolicySysProcsReclaimedFirst:
+               case kJetsamAgingPolicyAppsReclaimedFirst:
+                       bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
+                       jld_bucket_count = bucket->count;
+                       bucket = &memstat_bucket[system_procs_aging_band];
+                       jld_bucket_count += bucket->count;
+                       bucket = &memstat_bucket[applications_aging_band];
+                       jld_bucket_count += bucket->count;
+                       break;
+               case kJetsamAgingPolicyNone:
+               default:
+                       bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
+                       jld_bucket_count = bucket->count;
+                       break;
+               }
+
+               bucket = &memstat_bucket[JETSAM_PRIORITY_ELEVATED_INACTIVE];
+               elevated_bucket_count = bucket->count;
+
+               proc_list_unlock();
 
+               /*
+                * memorystatus_jld_eval_period_msecs is a tunable
+                * memorystatus_jld_eval_aggressive_count is a tunable
+                * memorystatus_jld_eval_aggressive_priority_band_max is a tunable
+                */
+               if ((jld_bucket_count == 0) ||
+                   (jld_now_msecs > (jld_timestamp_msecs + memorystatus_jld_eval_period_msecs))) {
                        /*
-                        * memorystatus_jld_eval_period_msecs is a tunable
-                        * memorystatus_jld_eval_aggressive_count is a tunable
-                        * memorystatus_jld_eval_aggressive_priority_band_max is a tunable
+                        * Refresh evaluation parameters
                         */
-                       if ( (jld_bucket_count == 0) || 
-                            (jld_now_msecs > (jld_timestamp_msecs + memorystatus_jld_eval_period_msecs))) {
+                       jld_timestamp_msecs      = jld_now_msecs;
+                       jld_idle_kill_candidates = jld_bucket_count;
+                       *jld_idle_kills          = 0;
+                       jld_eval_aggressive_count = 0;
+                       jld_priority_band_max   = JETSAM_PRIORITY_UI_SUPPORT;
+               }
+
+               if (*jld_idle_kills > jld_idle_kill_candidates) {
+                       jld_eval_aggressive_count++;
 
-                               /* 
-                                * Refresh evaluation parameters 
+#if DEVELOPMENT || DEBUG
+                       printf("memorystatus: aggressive%d: beginning of window: %lld ms, : timestamp now: %lld ms\n",
+                           jld_eval_aggressive_count,
+                           jld_timestamp_msecs,
+                           jld_now_msecs);
+                       printf("memorystatus: aggressive%d: idle candidates: %d, idle kills: %d\n",
+                           jld_eval_aggressive_count,
+                           jld_idle_kill_candidates,
+                           *jld_idle_kills);
+#endif /* DEVELOPMENT || DEBUG */
+
+                       if ((jld_eval_aggressive_count == memorystatus_jld_eval_aggressive_count) &&
+                           (total_corpses_count() > 0) && (*corpse_list_purged == FALSE)) {
+                               /*
+                                * If we reach this aggressive cycle, corpses might be causing memory pressure.
+                                * So, in an effort to avoid jetsams in the FG band, we will attempt to purge
+                                * corpse memory prior to this final march through JETSAM_PRIORITY_UI_SUPPORT.
                                 */
-                               jld_timestamp_msecs      = jld_now_msecs;
-                               jld_idle_kill_candidates = jld_bucket_count;
-                               jld_idle_kills           = 0;
-                               jld_eval_aggressive_count = 0;
-                               jld_priority_band_max   = JETSAM_PRIORITY_UI_SUPPORT;
+                               task_purge_all_corpses();
+                               *corpse_list_purged = TRUE;
+                       } else if (jld_eval_aggressive_count > memorystatus_jld_eval_aggressive_count) {
+                               /*
+                                * Bump up the jetsam priority limit (eg: the bucket index)
+                                * Enforce bucket index sanity.
+                                */
+                               if ((memorystatus_jld_eval_aggressive_priority_band_max < 0) ||
+                                   (memorystatus_jld_eval_aggressive_priority_band_max >= MEMSTAT_BUCKET_COUNT)) {
+                                       /*
+                                        * Do nothing.  Stick with the default level.
+                                        */
+                               } else {
+                                       jld_priority_band_max = memorystatus_jld_eval_aggressive_priority_band_max;
+                               }
                        }
 
-                       if (jld_idle_kills > jld_idle_kill_candidates) {
-                               jld_eval_aggressive_count++;
-                               if (jld_eval_aggressive_count > memorystatus_jld_eval_aggressive_count) {
-                                       /* 
-                                        * Bump up the jetsam priority limit (eg: the bucket index)
-                                        * Enforce bucket index sanity.
-                                        */
-                                       if ((memorystatus_jld_eval_aggressive_priority_band_max < 0) || 
-                                           (memorystatus_jld_eval_aggressive_priority_band_max >= MEMSTAT_BUCKET_COUNT)) {
+                       /* Visit elevated processes first */
+                       while (elevated_bucket_count) {
+                               elevated_bucket_count--;
+
+                               /*
+                                * memorystatus_kill_elevated_process() drops a reference,
+                                * so take another one so we can continue to use this exit reason
+                                * even after it returns.
+                                */
+
+                               os_reason_ref(jetsam_reason);
+                               killed = memorystatus_kill_elevated_process(
+                                       cause,
+                                       jetsam_reason,
+                                       JETSAM_PRIORITY_ELEVATED_INACTIVE,
+                                       jld_eval_aggressive_count,
+                                       &errors);
+
+                               if (killed) {
+                                       *post_snapshot = TRUE;
+                                       if (memorystatus_avail_pages_below_pressure()) {
                                                /*
-                                                * Do nothing.  Stick with the default level.
+                                                * Still under pressure.
+                                                * Find another pinned processes.
                                                 */
+                                               continue;
                                        } else {
-                                               jld_priority_band_max = memorystatus_jld_eval_aggressive_priority_band_max;
+                                               return TRUE;
                                        }
+                               } else {
+                                       /*
+                                        * No pinned processes left to kill.
+                                        * Abandon elevated band.
+                                        */
+                                       break;
                                }
+                       }
 
-                               killed = memorystatus_kill_top_process_aggressive(
-                                       TRUE, 
-                                       kMemorystatusKilledVMThrashing,
-                                       jld_eval_aggressive_count, 
-                                       jld_priority_band_max, 
-                                       &errors);
+                       /*
+                        * memorystatus_kill_top_process_aggressive() allocates its own
+                        * jetsam_reason so the kMemorystatusKilledProcThrashing cause
+                        * is consistent throughout the aggressive march.
+                        */
+                       killed = memorystatus_kill_top_process_aggressive(
+                               kMemorystatusKilledProcThrashing,
+                               jld_eval_aggressive_count,
+                               jld_priority_band_max,
+                               &errors);
 
-                                       
-                               if (killed) {
-                                       /* Always generate logs after aggressive kill */
-                                       post_snapshot = TRUE;
-                                       goto done;
-                               } 
-                       } 
+                       if (killed) {
+                               /* Always generate logs after aggressive kill */
+                               *post_snapshot = TRUE;
+                               *jld_idle_kills = 0;
+                               return TRUE;
+                       }
+               }
+
+               return FALSE;
+       }
+
+       return FALSE;
+}
+
+
+static void
+memorystatus_thread(void *param __unused, wait_result_t wr __unused)
+{
+       boolean_t post_snapshot = FALSE;
+       uint32_t errors = 0;
+       uint32_t hwm_kill = 0;
+       boolean_t sort_flag = TRUE;
+       boolean_t corpse_list_purged = FALSE;
+       int     jld_idle_kills = 0;
+       struct jetsam_thread_state *jetsam_thread = jetsam_current_thread();
+
+       if (jetsam_thread->inited == FALSE) {
+               /*
+                * It's the first time the thread has run, so just mark the thread as privileged and block.
+                * This avoids a spurious pass with unset variables, as set out in <rdar://problem/9609402>.
+                */
+
+               char name[32];
+               thread_wire(host_priv_self(), current_thread(), TRUE);
+               snprintf(name, 32, "VM_memorystatus_%d", jetsam_thread->index + 1);
+
+               if (jetsam_thread->index == 0) {
+                       if (vm_pageout_state.vm_restricted_to_single_processor == TRUE) {
+                               thread_vm_bind_group_add();
+                       }
+               }
+               thread_set_thread_name(current_thread(), name);
+               jetsam_thread->inited = TRUE;
+               memorystatus_thread_block(0, memorystatus_thread);
+       }
+
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_SCAN) | DBG_FUNC_START,
+           memorystatus_available_pages, memorystatus_jld_enabled, memorystatus_jld_eval_period_msecs, memorystatus_jld_eval_aggressive_count, 0);
+
+       /*
+        * Jetsam aware version.
+        *
+        * The VM pressure notification thread is working it's way through clients in parallel.
+        *
+        * So, while the pressure notification thread is targeting processes in order of
+        * increasing jetsam priority, we can hopefully reduce / stop it's work by killing
+        * any processes that have exceeded their highwater mark.
+        *
+        * If we run out of HWM processes and our available pages drops below the critical threshold, then,
+        * we target the least recently used process in order of increasing jetsam priority (exception: the FG band).
+        */
+       while (memorystatus_action_needed()) {
+               boolean_t killed;
+               int32_t priority;
+               uint32_t cause;
+               uint64_t jetsam_reason_code = JETSAM_REASON_INVALID;
+               os_reason_t jetsam_reason = OS_REASON_NULL;
+
+               cause = kill_under_pressure_cause;
+               switch (cause) {
+               case kMemorystatusKilledFCThrashing:
+                       jetsam_reason_code = JETSAM_REASON_MEMORY_FCTHRASHING;
+                       break;
+               case kMemorystatusKilledVMCompressorThrashing:
+                       jetsam_reason_code = JETSAM_REASON_MEMORY_VMCOMPRESSOR_THRASHING;
+                       break;
+               case kMemorystatusKilledVMCompressorSpaceShortage:
+                       jetsam_reason_code = JETSAM_REASON_MEMORY_VMCOMPRESSOR_SPACE_SHORTAGE;
+                       break;
+               case kMemorystatusKilledZoneMapExhaustion:
+                       jetsam_reason_code = JETSAM_REASON_ZONE_MAP_EXHAUSTION;
+                       break;
+               case kMemorystatusKilledVMPageShortage:
+               /* falls through */
+               default:
+                       jetsam_reason_code = JETSAM_REASON_MEMORY_VMPAGESHORTAGE;
+                       cause = kMemorystatusKilledVMPageShortage;
+                       break;
+               }
+
+               /* Highwater */
+               boolean_t is_critical = TRUE;
+               if (memorystatus_act_on_hiwat_processes(&errors, &hwm_kill, &post_snapshot, &is_critical)) {
+                       if (is_critical == FALSE) {
+                               /*
+                                * For now, don't kill any other processes.
+                                */
+                               break;
+                       } else {
+                               goto done;
+                       }
                }
-               
+
+               jetsam_reason = os_reason_create(OS_REASON_JETSAM, jetsam_reason_code);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_thread: failed to allocate jetsam reason\n");
+               }
+
+               if (memorystatus_act_aggressive(cause, jetsam_reason, &jld_idle_kills, &corpse_list_purged, &post_snapshot)) {
+                       goto done;
+               }
+
+               /*
+                * memorystatus_kill_top_process() drops a reference,
+                * so take another one so we can continue to use this exit reason
+                * even after it returns
+                */
+               os_reason_ref(jetsam_reason);
+
                /* LRU */
-               killed = memorystatus_kill_top_process(TRUE, sort_flag, cause, &priority, &errors);
+               killed = memorystatus_kill_top_process(TRUE, sort_flag, cause, jetsam_reason, &priority, &errors);
                sort_flag = FALSE;
 
                if (killed) {
-                       /*
-                        * Don't generate logs for steady-state idle-exit kills,
-                        * unless it is overridden for debug or by the device
-                        * tree.
-                        */
-                       if ((priority != JETSAM_PRIORITY_IDLE) || memorystatus_idle_snapshot) {
-                               post_snapshot = TRUE;
+                       if (memorystatus_post_snapshot(priority, cause) == TRUE) {
+                               post_snapshot = TRUE;
                        }
 
                        /* Jetsam Loop Detection */
                        if (memorystatus_jld_enabled == TRUE) {
-                               if ((priority == JETSAM_PRIORITY_IDLE) || (priority == JETSAM_PRIORITY_IDLE_DEFERRED)) {
+                               if ((priority == JETSAM_PRIORITY_IDLE) || (priority == system_procs_aging_band) || (priority == applications_aging_band)) {
                                        jld_idle_kills++;
                                } else {
                                        /*
@@ -2624,88 +4453,110 @@ memorystatus_thread(void *param __unused, wait_result_t wr __unused)
                                         */
                                }
                        }
+
+                       if ((priority >= JETSAM_PRIORITY_UI_SUPPORT) && (total_corpses_count() > 0) && (corpse_list_purged == FALSE)) {
+                               /*
+                                * If we have jetsammed a process in or above JETSAM_PRIORITY_UI_SUPPORT
+                                * then we attempt to relieve pressure by purging corpse memory.
+                                */
+                               task_purge_all_corpses();
+                               corpse_list_purged = TRUE;
+                       }
                        goto done;
                }
-               
-               if (memorystatus_available_pages <= memorystatus_available_pages_critical) {
-                       /* Under pressure and unable to kill a process - panic */
-                       panic("memorystatus_jetsam_thread: no victim! available pages:%d\n", memorystatus_available_pages);
+
+               if (memorystatus_avail_pages_below_critical()) {
+                       /*
+                        * Still under pressure and unable to kill a process - purge corpse memory
+                        */
+                       if (total_corpses_count() > 0) {
+                               task_purge_all_corpses();
+                               corpse_list_purged = TRUE;
+                       }
+
+                       if (memorystatus_avail_pages_below_critical()) {
+                               /*
+                                * Still under pressure and unable to kill a process - panic
+                                */
+                               panic("memorystatus_jetsam_thread: no victim! available pages:%llu\n", (uint64_t)memorystatus_available_pages);
+                       }
                }
-                       
-done:          
+
+done:
 
                /*
                 * We do not want to over-kill when thrashing has been detected.
                 * To avoid that, we reset the flag here and notify the
                 * compressor.
                 */
-               if (is_thrashing(kill_under_pressure_cause)) {
+               if (is_reason_thrashing(kill_under_pressure_cause)) {
                        kill_under_pressure_cause = 0;
+#if CONFIG_JETSAM
                        vm_thrashing_jetsam_done();
+#endif /* CONFIG_JETSAM */
+               } else if (is_reason_zone_map_exhaustion(kill_under_pressure_cause)) {
+                       kill_under_pressure_cause = 0;
                }
+
+               os_reason_free(jetsam_reason);
        }
 
        kill_under_pressure_cause = 0;
-       
+
        if (errors) {
                memorystatus_clear_errors();
        }
 
-#if VM_PRESSURE_EVENTS
-       /*
-        * LD: We used to target the foreground process first and foremost here.
-        * Now, we target all processes, starting from the non-suspended, background
-        * processes first. We will target foreground too.
-        *
-        * memorystatus_update_vm_pressure(TRUE);
-        */
-       //vm_pressure_response();
-#endif
-
        if (post_snapshot) {
+               proc_list_lock();
                size_t snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) +
-                       sizeof(memorystatus_jetsam_snapshot_entry_t) * (memorystatus_jetsam_snapshot_count);
+                   sizeof(memorystatus_jetsam_snapshot_entry_t) * (memorystatus_jetsam_snapshot_count);
                uint64_t timestamp_now = mach_absolute_time();
                memorystatus_jetsam_snapshot->notification_time = timestamp_now;
-               if (memorystatus_jetsam_snapshot_last_timestamp == 0 ||
-                               timestamp_now > memorystatus_jetsam_snapshot_last_timestamp + memorystatus_jetsam_snapshot_timeout) {
+               memorystatus_jetsam_snapshot->js_gencount++;
+               if (memorystatus_jetsam_snapshot_count > 0 && (memorystatus_jetsam_snapshot_last_timestamp == 0 ||
+                   timestamp_now > memorystatus_jetsam_snapshot_last_timestamp + memorystatus_jetsam_snapshot_timeout)) {
+                       proc_list_unlock();
                        int ret = memorystatus_send_note(kMemorystatusSnapshotNote, &snapshot_size, sizeof(snapshot_size));
                        if (!ret) {
                                proc_list_lock();
                                memorystatus_jetsam_snapshot_last_timestamp = timestamp_now;
                                proc_list_unlock();
                        }
+               } else {
+                       proc_list_unlock();
                }
        }
 
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_SCAN) | DBG_FUNC_END,
-               memorystatus_available_pages, 0, 0, 0, 0);
-
-#else /* CONFIG_JETSAM */
-
-       /*
-        * Jetsam not enabled
-        */
-
-#endif /* CONFIG_JETSAM */
+           memorystatus_available_pages, 0, 0, 0, 0);
 
        memorystatus_thread_block(0, memorystatus_thread);
 }
 
-#if !CONFIG_JETSAM
 /*
  * Returns TRUE:
- *     when an idle-exitable proc was killed
+ *      when an idle-exitable proc was killed
  * Returns FALSE:
  *     when there are no more idle-exitable procs found
- *     when the attempt to kill an idle-exitable proc failed
+ *      when the attempt to kill an idle-exitable proc failed
  */
-boolean_t memorystatus_idle_exit_from_VM(void) {
-       return(kill_idle_exit_proc());
-}
-#endif /* !CONFIG_JETSAM */
+boolean_t
+memorystatus_idle_exit_from_VM(void)
+{
+       /*
+        * This routine should no longer be needed since we are
+        * now using jetsam bands on all platforms and so will deal
+        * with IDLE processes within the memorystatus thread itself.
+        *
+        * But we still use it because we observed that macos systems
+        * started heavy compression/swapping with a bunch of
+        * idle-exitable processes alive and doing nothing. We decided
+        * to rather kill those processes than start swapping earlier.
+        */
 
-#if CONFIG_JETSAM
+       return kill_idle_exit_proc();
+}
 
 /*
  * Callback invoked when allowable physical memory footprint exceeded
@@ -2715,243 +4566,847 @@ boolean_t memorystatus_idle_exit_from_VM(void) {
  * as well as the fatal task memory limits.
  */
 void
-memorystatus_on_ledger_footprint_exceeded(boolean_t warning, const int max_footprint_mb)
+memorystatus_on_ledger_footprint_exceeded(boolean_t warning, boolean_t memlimit_is_active, boolean_t memlimit_is_fatal)
 {
-       boolean_t is_active;
-       boolean_t is_fatal;
+       os_reason_t jetsam_reason = OS_REASON_NULL;
 
        proc_t p = current_proc();
 
-       proc_list_lock();
+#if VM_PRESSURE_EVENTS
+       if (warning == TRUE) {
+               /*
+                * This is a warning path which implies that the current process is close, but has
+                * not yet exceeded its per-process memory limit.
+                */
+               if (memorystatus_warn_process(p->p_pid, memlimit_is_active, memlimit_is_fatal, FALSE /* not exceeded */) != TRUE) {
+                       /* Print warning, since it's possible that task has not registered for pressure notifications */
+                       os_log(OS_LOG_DEFAULT, "memorystatus_on_ledger_footprint_exceeded: failed to warn the current task (%d exiting, or no handler registered?).\n", p->p_pid);
+               }
+               return;
+       }
+#endif /* VM_PRESSURE_EVENTS */
 
-       is_active = proc_jetsam_state_is_active_locked(p);
-       is_fatal = (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT);
+       if (memlimit_is_fatal) {
+               /*
+                * If this process has no high watermark or has a fatal task limit, then we have been invoked because the task
+                * has violated either the system-wide per-task memory limit OR its own task limit.
+                */
+               jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_PERPROCESSLIMIT);
+               if (jetsam_reason == NULL) {
+                       printf("task_exceeded footprint: failed to allocate jetsam reason\n");
+               } else if (corpse_for_fatal_memkill != 0 && proc_send_synchronous_EXC_RESOURCE(p) == FALSE) {
+                       /* Set OS_REASON_FLAG_GENERATE_CRASH_REPORT to generate corpse */
+                       jetsam_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
+               }
 
-       if (warning == FALSE) {
+               if (memorystatus_kill_process_sync(p->p_pid, kMemorystatusKilledPerProcessLimit, jetsam_reason) != TRUE) {
+                       printf("task_exceeded_footprint: failed to kill the current task (exiting?).\n");
+               }
+       } else {
                /*
-                * We only want the EXC_RESOURCE to trigger once per lifetime
-                * of the active/inactive limit state. So, here, we detect the
-                * active/inactive state of the process and mark the
-                * state as exception has been triggered.
+                * HWM offender exists. Done without locks or synchronization.
+                * See comment near its declaration for more details.
+                */
+               memorystatus_hwm_candidates = TRUE;
+
+#if VM_PRESSURE_EVENTS
+               /*
+                * The current process is not in the warning path.
+                * This path implies the current process has exceeded a non-fatal (soft) memory limit.
+                * Failure to send note is ignored here.
                 */
-               if (is_active == TRUE) {
+               (void)memorystatus_warn_process(p->p_pid, memlimit_is_active, memlimit_is_fatal, TRUE /* exceeded */);
+
+#endif /* VM_PRESSURE_EVENTS */
+       }
+}
+
+void
+memorystatus_log_exception(const int max_footprint_mb, boolean_t memlimit_is_active, boolean_t memlimit_is_fatal)
+{
+       proc_t p = current_proc();
+
+       /*
+        * The limit violation is logged here, but only once per process per limit.
+        * Soft memory limit is a non-fatal high-water-mark
+        * Hard memory limit is a fatal custom-task-limit or system-wide per-task memory limit.
+        */
+
+       os_log_with_startup_serial(OS_LOG_DEFAULT, "EXC_RESOURCE -> %s[%d] exceeded mem limit: %s%s %d MB (%s)\n",
+           (*p->p_name ? p->p_name : "unknown"), p->p_pid, (memlimit_is_active ? "Active" : "Inactive"),
+           (memlimit_is_fatal  ? "Hard" : "Soft"), max_footprint_mb,
+           (memlimit_is_fatal  ? "fatal" : "non-fatal"));
+
+       return;
+}
+
+
+/*
+ * Description:
+ *     Evaluates process state to determine which limit
+ *     should be applied (active vs. inactive limit).
+ *
+ *     Processes that have the 'elevated inactive jetsam band' attribute
+ *     are first evaluated based on their current priority band.
+ *     presently elevated ==> active
+ *
+ *     Processes that opt into dirty tracking are evaluated
+ *     based on clean vs dirty state.
+ *     dirty ==> active
+ *     clean ==> inactive
+ *
+ *     Process that do not opt into dirty tracking are
+ *     evalulated based on priority level.
+ *     Foreground or above ==> active
+ *     Below Foreground    ==> inactive
+ *
+ *     Return: TRUE if active
+ *             False if inactive
+ */
+
+static boolean_t
+proc_jetsam_state_is_active_locked(proc_t p)
+{
+       if ((p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND) &&
+           (p->p_memstat_effectivepriority == JETSAM_PRIORITY_ELEVATED_INACTIVE)) {
+               /*
+                * process has the 'elevated inactive jetsam band' attribute
+                * and process is present in the elevated band
+                * implies active state
+                */
+               return TRUE;
+       } else if (p->p_memstat_dirty & P_DIRTY_TRACK) {
+               /*
+                * process has opted into dirty tracking
+                * active state is based on dirty vs. clean
+                */
+               if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY) {
                        /*
-                        * turn off exceptions for active state
+                        * process is dirty
+                        * implies active state
                         */
-                       p->p_memstat_state |= P_MEMSTAT_MEMLIMIT_ACTIVE_EXC_TRIGGERED;
+                       return TRUE;
                } else {
                        /*
-                        * turn off exceptions for inactive state
+                        * process is clean
+                        * implies inactive state
                         */
-                       p->p_memstat_state |= P_MEMSTAT_MEMLIMIT_INACTIVE_EXC_TRIGGERED;
+                       return FALSE;
                }
-
+       } else if (p->p_memstat_effectivepriority >= JETSAM_PRIORITY_FOREGROUND) {
                /*
-                * Soft memory limit is a non-fatal high-water-mark
-                * Hard memory limit is a fatal custom-task-limit or system-wide per-task memory limit.
+                * process is Foreground or higher
+                * implies active state
                 */
-               printf("process %d (%s) exceeded physical memory footprint, the %s%sMemoryLimit of %d MB\n",
-                      p->p_pid, p->p_comm, (is_active ? "Active" : "Inactive"),
-                      (is_fatal  ? "Hard" : "Soft"), max_footprint_mb);
+               return TRUE;
+       } else {
+               /*
+                * process found below Foreground
+                * implies inactive state
+                */
+               return FALSE;
+       }
+}
+
+static boolean_t
+memorystatus_kill_process_sync(pid_t victim_pid, uint32_t cause, os_reason_t jetsam_reason)
+{
+       boolean_t res;
+
+       uint32_t errors = 0;
+
+       if (victim_pid == -1) {
+               /* No pid, so kill first process */
+               res = memorystatus_kill_top_process(TRUE, TRUE, cause, jetsam_reason, NULL, &errors);
+       } else {
+               res = memorystatus_kill_specific_process(victim_pid, cause, jetsam_reason);
+       }
+
+       if (errors) {
+               memorystatus_clear_errors();
+       }
+
+       if (res == TRUE) {
+               /* Fire off snapshot notification */
+               proc_list_lock();
+               size_t snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) +
+                   sizeof(memorystatus_jetsam_snapshot_entry_t) * memorystatus_jetsam_snapshot_count;
+               uint64_t timestamp_now = mach_absolute_time();
+               memorystatus_jetsam_snapshot->notification_time = timestamp_now;
+               if (memorystatus_jetsam_snapshot_count > 0 && (memorystatus_jetsam_snapshot_last_timestamp == 0 ||
+                   timestamp_now > memorystatus_jetsam_snapshot_last_timestamp + memorystatus_jetsam_snapshot_timeout)) {
+                       proc_list_unlock();
+                       int ret = memorystatus_send_note(kMemorystatusSnapshotNote, &snapshot_size, sizeof(snapshot_size));
+                       if (!ret) {
+                               proc_list_lock();
+                               memorystatus_jetsam_snapshot_last_timestamp = timestamp_now;
+                               proc_list_unlock();
+                       }
+               } else {
+                       proc_list_unlock();
+               }
+       }
+
+       return res;
+}
+
+/*
+ * Jetsam a specific process.
+ */
+static boolean_t
+memorystatus_kill_specific_process(pid_t victim_pid, uint32_t cause, os_reason_t jetsam_reason)
+{
+       boolean_t killed;
+       proc_t p;
+       uint64_t killtime = 0;
+       clock_sec_t     tv_sec;
+       clock_usec_t    tv_usec;
+       uint32_t        tv_msec;
+
+       /* TODO - add a victim queue and push this into the main jetsam thread */
+
+       p = proc_find(victim_pid);
+       if (!p) {
+               os_reason_free(jetsam_reason);
+               return FALSE;
+       }
 
+       proc_list_lock();
+
+       if (memorystatus_jetsam_snapshot_count == 0) {
+               memorystatus_init_jetsam_snapshot_locked(NULL, 0);
        }
 
+       killtime = mach_absolute_time();
+       absolutetime_to_microtime(killtime, &tv_sec, &tv_usec);
+       tv_msec = tv_usec / 1000;
+
+       memorystatus_update_jetsam_snapshot_entry_locked(p, cause, killtime);
+
        proc_list_unlock();
 
-#if VM_PRESSURE_EVENTS
-       if (warning == TRUE) {
-               if (memorystatus_warn_process(p->p_pid, TRUE /* critical? */) != TRUE) {
-                       /* Print warning, since it's possible that task has not registered for pressure notifications */
-                       printf("task_exceeded_footprint: failed to warn the current task (exiting, or no handler registered?).\n");
+       os_log_with_startup_serial(OS_LOG_DEFAULT, "%lu.%03d memorystatus: killing_specific_process pid %d [%s] (%s %d) - memorystatus_available_pages: %llu\n",
+           (unsigned long)tv_sec, tv_msec, victim_pid, (*p->p_name ? p->p_name : "unknown"),
+           memorystatus_kill_cause_name[cause], p->p_memstat_effectivepriority, (uint64_t)memorystatus_available_pages);
+
+       killed = memorystatus_do_kill(p, cause, jetsam_reason);
+       proc_rele(p);
+
+       return killed;
+}
+
+
+/*
+ * Toggle the P_MEMSTAT_TERMINATED state.
+ * Takes the proc_list_lock.
+ */
+void
+proc_memstat_terminated(proc_t p, boolean_t set)
+{
+#if DEVELOPMENT || DEBUG
+       if (p) {
+               proc_list_lock();
+               if (set == TRUE) {
+                       p->p_memstat_state |= P_MEMSTAT_TERMINATED;
+               } else {
+                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
                }
-               return;
+               proc_list_unlock();
        }
-#endif /* VM_PRESSURE_EVENTS */
+#else
+#pragma unused(p, set)
+       /*
+        * do nothing
+        */
+#endif /* DEVELOPMENT || DEBUG */
+       return;
+}
+
+
+#if CONFIG_JETSAM
+/*
+ * This is invoked when cpulimits have been exceeded while in fatal mode.
+ * The jetsam_flags do not apply as those are for memory related kills.
+ * We call this routine so that the offending process is killed with
+ * a non-zero exit status.
+ */
+void
+jetsam_on_ledger_cpulimit_exceeded(void)
+{
+       int retval = 0;
+       int jetsam_flags = 0;  /* make it obvious */
+       proc_t p = current_proc();
+       os_reason_t jetsam_reason = OS_REASON_NULL;
+
+       printf("task_exceeded_cpulimit: killing pid %d [%s]\n",
+           p->p_pid, (*p->p_name ? p->p_name : "(unknown)"));
 
-       if (is_fatal) {
+       jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_CPULIMIT);
+       if (jetsam_reason == OS_REASON_NULL) {
+               printf("task_exceeded_cpulimit: unable to allocate memory for jetsam reason\n");
+       }
+
+       retval = jetsam_do_kill(p, jetsam_flags, jetsam_reason);
+
+       if (retval) {
+               printf("task_exceeded_cpulimit: failed to kill current task (exiting?).\n");
+       }
+}
+
+#endif /* CONFIG_JETSAM */
+
+static void
+memorystatus_get_task_memory_region_count(task_t task, uint64_t *count)
+{
+       assert(task);
+       assert(count);
+
+       *count = get_task_memory_region_count(task);
+}
+
+
+#define MEMORYSTATUS_VM_MAP_FORK_ALLOWED     0x100000000
+#define MEMORYSTATUS_VM_MAP_FORK_NOT_ALLOWED 0x200000000
+
+#if DEVELOPMENT || DEBUG
+
+/*
+ * Sysctl only used to test memorystatus_allowed_vm_map_fork() path.
+ *   set a new pidwatch value
+ *     or
+ *   get the current pidwatch value
+ *
+ * The pidwatch_val starts out with a PID to watch for in the map_fork path.
+ * Its value is:
+ * - OR'd with MEMORYSTATUS_VM_MAP_FORK_ALLOWED if we allow the map_fork.
+ * - OR'd with MEMORYSTATUS_VM_MAP_FORK_NOT_ALLOWED if we disallow the map_fork.
+ * - set to -1ull if the map_fork() is aborted for other reasons.
+ */
+
+uint64_t memorystatus_vm_map_fork_pidwatch_val = 0;
+
+static int sysctl_memorystatus_vm_map_fork_pidwatch SYSCTL_HANDLER_ARGS {
+#pragma unused(oidp, arg1, arg2)
+
+       uint64_t new_value = 0;
+       uint64_t old_value = 0;
+       int error = 0;
+
+       /*
+        * The pid is held in the low 32 bits.
+        * The 'allowed' flags are in the upper 32 bits.
+        */
+       old_value = memorystatus_vm_map_fork_pidwatch_val;
+
+       error = sysctl_io_number(req, old_value, sizeof(old_value), &new_value, NULL);
+
+       if (error || !req->newptr) {
                /*
-                * If this process has no high watermark or has a fatal task limit, then we have been invoked because the task
-                * has violated either the system-wide per-task memory limit OR its own task limit.
+                * No new value passed in.
                 */
-               if (memorystatus_kill_process_sync(p->p_pid, kMemorystatusKilledPerProcessLimit) != TRUE) {
-                       printf("task_exceeded_footprint: failed to kill the current task (exiting?).\n");
+               return error;
+       }
+
+       /*
+        * A new pid was passed in via req->newptr.
+        * Ignore any attempt to set the higher order bits.
+        */
+       memorystatus_vm_map_fork_pidwatch_val = new_value & 0xFFFFFFFF;
+       printf("memorystatus: pidwatch old_value = 0x%llx, new_value = 0x%llx \n", old_value, new_value);
+
+       return error;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_map_fork_pidwatch, CTLTYPE_QUAD | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+    0, 0, sysctl_memorystatus_vm_map_fork_pidwatch, "Q", "get/set pid watched for in vm_map_fork");
+
+
+/*
+ * Record if a watched process fails to qualify for a vm_map_fork().
+ */
+void
+memorystatus_abort_vm_map_fork(task_t task)
+{
+       if (memorystatus_vm_map_fork_pidwatch_val != 0) {
+               proc_t p = get_bsdtask_info(task);
+               if (p != NULL && memorystatus_vm_map_fork_pidwatch_val == (uint64_t)p->p_pid) {
+                       memorystatus_vm_map_fork_pidwatch_val = -1ull;
                }
-       } else {
-               /*
-                * HWM offender exists. Done without locks or synchronization.
-                * See comment near its declaration for more details.
-                */
-               memorystatus_hwm_candidates = TRUE;
        }
 }
 
+static void
+set_vm_map_fork_pidwatch(task_t task, uint64_t x)
+{
+       if (memorystatus_vm_map_fork_pidwatch_val != 0) {
+               proc_t p = get_bsdtask_info(task);
+               if (p && (memorystatus_vm_map_fork_pidwatch_val == (uint64_t)p->p_pid)) {
+                       memorystatus_vm_map_fork_pidwatch_val |= x;
+               }
+       }
+}
+
+#else /* DEVELOPMENT || DEBUG */
+
+
+static void
+set_vm_map_fork_pidwatch(task_t task, uint64_t x)
+{
+#pragma unused(task)
+#pragma unused(x)
+}
+
+#endif /* DEVELOPMENT || DEBUG */
+
 /*
- * Toggle the P_MEMSTAT_TERMINATED state.
- * Takes the proc_list_lock.
+ * Called during EXC_RESOURCE handling when a process exceeds a soft
+ * memory limit.  This is the corpse fork path and here we decide if
+ * vm_map_fork will be allowed when creating the corpse.
+ * The task being considered is suspended.
+ *
+ * By default, a vm_map_fork is allowed to proceed.
+ *
+ * A few simple policy assumptions:
+ *     Desktop platform is not considered in this path.
+ *     The vm_map_fork is always allowed.
+ *
+ *     If the device has a zero system-wide task limit,
+ *     then the vm_map_fork is allowed.
+ *
+ *     And if a process's memory footprint calculates less
+ *     than or equal to half of the system-wide task limit,
+ *     then the vm_map_fork is allowed.  This calculation
+ *     is based on the assumption that a process can
+ *     munch memory up to the system-wide task limit.
  */
-void
-proc_memstat_terminated(proc_t p, boolean_t set)
+boolean_t
+memorystatus_allowed_vm_map_fork(task_t task)
 {
-#if DEVELOPMENT || DEBUG
-       if (p) {
-               proc_list_lock();
-               if (set == TRUE) {
-                       p->p_memstat_state |= P_MEMSTAT_TERMINATED;
-               } else {
-                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
-               }
-               proc_list_unlock();
+       boolean_t is_allowed = TRUE;   /* default */
+
+#if CONFIG_EMBEDDED
+
+       uint64_t footprint_in_bytes;
+       uint64_t max_allowed_bytes;
+
+       if (max_task_footprint_mb == 0) {
+               set_vm_map_fork_pidwatch(task, MEMORYSTATUS_VM_MAP_FORK_ALLOWED);
+               return is_allowed;
        }
-#else
-#pragma unused(p, set)
+
+       footprint_in_bytes = get_task_phys_footprint(task);
+
        /*
-        * do nothing
+        * Maximum is 1/4 of the system-wide task limit.
         */
-#endif /* DEVELOPMENT || DEBUG */
-       return;
+       max_allowed_bytes = ((uint64_t)max_task_footprint_mb * 1024 * 1024) >> 2;
+
+       if (footprint_in_bytes > max_allowed_bytes) {
+               printf("memorystatus disallowed vm_map_fork %lld  %lld\n", footprint_in_bytes, max_allowed_bytes);
+               set_vm_map_fork_pidwatch(task, MEMORYSTATUS_VM_MAP_FORK_NOT_ALLOWED);
+               return !is_allowed;
+       }
+#endif /* CONFIG_EMBEDDED */
+
+       set_vm_map_fork_pidwatch(task, MEMORYSTATUS_VM_MAP_FORK_ALLOWED);
+       return is_allowed;
 }
 
-/*
- * This is invoked when cpulimits have been exceeded while in fatal mode.
- * The jetsam_flags do not apply as those are for memory related kills.
- * We call this routine so that the offending process is killed with 
- * a non-zero exit status.
- */
-void
-jetsam_on_ledger_cpulimit_exceeded(void)
+static void
+memorystatus_get_task_page_counts(task_t task, uint32_t *footprint, uint32_t *max_footprint_lifetime, uint32_t *purgeable_pages)
 {
-       int retval = 0;
-       int jetsam_flags = 0;  /* make it obvious */
-       proc_t p = current_proc();
+       assert(task);
+       assert(footprint);
 
-       printf("task_exceeded_cpulimit: killing pid %d [%s]\n",
-              p->p_pid, (p->p_comm ? p->p_comm : "(unknown)"));
+       uint64_t pages;
 
-       retval = jetsam_do_kill(p, jetsam_flags);
-       
-       if (retval) {
-               printf("task_exceeded_cpulimit: failed to kill current task (exiting?).\n");
+       pages = (get_task_phys_footprint(task) / PAGE_SIZE_64);
+       assert(((uint32_t)pages) == pages);
+       *footprint = (uint32_t)pages;
+
+       if (max_footprint_lifetime) {
+               pages = (get_task_phys_footprint_lifetime_max(task) / PAGE_SIZE_64);
+               assert(((uint32_t)pages) == pages);
+               *max_footprint_lifetime = (uint32_t)pages;
+       }
+       if (purgeable_pages) {
+               pages = (get_task_purgeable_size(task) / PAGE_SIZE_64);
+               assert(((uint32_t)pages) == pages);
+               *purgeable_pages = (uint32_t)pages;
        }
 }
 
 static void
-memorystatus_get_task_page_counts(task_t task, uint32_t *footprint, uint32_t *max_footprint, uint32_t *max_footprint_lifetime, uint32_t *purgeable_pages)
+memorystatus_get_task_phys_footprint_page_counts(task_t task,
+    uint64_t *internal_pages, uint64_t *internal_compressed_pages,
+    uint64_t *purgeable_nonvolatile_pages, uint64_t *purgeable_nonvolatile_compressed_pages,
+    uint64_t *alternate_accounting_pages, uint64_t *alternate_accounting_compressed_pages,
+    uint64_t *iokit_mapped_pages, uint64_t *page_table_pages)
 {
        assert(task);
-       assert(footprint);
-    
-       *footprint = (uint32_t)(get_task_phys_footprint(task) / PAGE_SIZE_64);
-       if (max_footprint) {
-               *max_footprint = (uint32_t)(get_task_phys_footprint_max(task) / PAGE_SIZE_64);
+
+       if (internal_pages) {
+               *internal_pages = (get_task_internal(task) / PAGE_SIZE_64);
        }
-       if (max_footprint_lifetime) {
-               *max_footprint_lifetime = (uint32_t)(get_task_resident_max(task) / PAGE_SIZE_64);
+
+       if (internal_compressed_pages) {
+               *internal_compressed_pages = (get_task_internal_compressed(task) / PAGE_SIZE_64);
        }
-       if (purgeable_pages) {
-               *purgeable_pages = (uint32_t)(get_task_purgeable_size(task) / PAGE_SIZE_64);
+
+       if (purgeable_nonvolatile_pages) {
+               *purgeable_nonvolatile_pages = (get_task_purgeable_nonvolatile(task) / PAGE_SIZE_64);
+       }
+
+       if (purgeable_nonvolatile_compressed_pages) {
+               *purgeable_nonvolatile_compressed_pages = (get_task_purgeable_nonvolatile_compressed(task) / PAGE_SIZE_64);
+       }
+
+       if (alternate_accounting_pages) {
+               *alternate_accounting_pages = (get_task_alternate_accounting(task) / PAGE_SIZE_64);
+       }
+
+       if (alternate_accounting_compressed_pages) {
+               *alternate_accounting_compressed_pages = (get_task_alternate_accounting_compressed(task) / PAGE_SIZE_64);
+       }
+
+       if (iokit_mapped_pages) {
+               *iokit_mapped_pages = (get_task_iokit_mapped(task) / PAGE_SIZE_64);
+       }
+
+       if (page_table_pages) {
+               *page_table_pages = (get_task_page_table(task) / PAGE_SIZE_64);
        }
 }
 
+/*
+ * This routine only acts on the global jetsam event snapshot.
+ * Updating the process's entry can race when the memorystatus_thread
+ * has chosen to kill a process that is racing to exit on another core.
+ */
 static void
-memorystatus_update_jetsam_snapshot_entry_locked(proc_t p, uint32_t kill_cause)
+memorystatus_update_jetsam_snapshot_entry_locked(proc_t p, uint32_t kill_cause, uint64_t killtime)
 {
+       memorystatus_jetsam_snapshot_entry_t *entry = NULL;
+       memorystatus_jetsam_snapshot_t *snapshot    = NULL;
+       memorystatus_jetsam_snapshot_entry_t *snapshot_list = NULL;
+
        unsigned int i;
 
+       LCK_MTX_ASSERT(proc_list_mlock, LCK_MTX_ASSERT_OWNED);
+
+       if (memorystatus_jetsam_snapshot_count == 0) {
+               /*
+                * No active snapshot.
+                * Nothing to do.
+                */
+               return;
+       }
+
+       /*
+        * Sanity check as this routine should only be called
+        * from a jetsam kill path.
+        */
+       assert(kill_cause != 0 && killtime != 0);
+
+       snapshot       = memorystatus_jetsam_snapshot;
+       snapshot_list  = memorystatus_jetsam_snapshot->entries;
+
        for (i = 0; i < memorystatus_jetsam_snapshot_count; i++) {
-               if (memorystatus_jetsam_snapshot_list[i].pid == p->p_pid) {
-                       /* Update if the priority has changed since the snapshot was taken */
-                       if (memorystatus_jetsam_snapshot_list[i].priority != p->p_memstat_effectivepriority) {
-                               memorystatus_jetsam_snapshot_list[i].priority = p->p_memstat_effectivepriority;
-                               strlcpy(memorystatus_jetsam_snapshot_list[i].name, p->p_comm, MAXCOMLEN+1);
-                               memorystatus_jetsam_snapshot_list[i].state = memorystatus_build_state(p);
-                               memorystatus_jetsam_snapshot_list[i].user_data = p->p_memstat_userdata;
-                               memorystatus_jetsam_snapshot_list[i].fds = p->p_fd->fd_nfiles;
+               if (snapshot_list[i].pid == p->p_pid) {
+                       entry = &snapshot_list[i];
+
+                       if (entry->killed || entry->jse_killtime) {
+                               /*
+                                * We apparently raced on the exit path
+                                * for this process, as it's snapshot entry
+                                * has already recorded a kill.
+                                */
+                               assert(entry->killed && entry->jse_killtime);
+                               break;
+                       }
+
+                       /*
+                        * Update the entry we just found in the snapshot.
+                        */
+
+                       entry->killed       = kill_cause;
+                       entry->jse_killtime = killtime;
+                       entry->jse_gencount = snapshot->js_gencount;
+                       entry->jse_idle_delta = p->p_memstat_idle_delta;
+#if CONFIG_FREEZE
+                       entry->jse_thaw_count = p->p_memstat_thaw_count;
+#else /* CONFIG_FREEZE */
+                       entry->jse_thaw_count = 0;
+#endif /* CONFIG_FREEZE */
+
+                       /*
+                        * If a process has moved between bands since snapshot was
+                        * initialized, then likely these fields changed too.
+                        */
+                       if (entry->priority != p->p_memstat_effectivepriority) {
+                               strlcpy(entry->name, p->p_name, sizeof(entry->name));
+                               entry->priority  = p->p_memstat_effectivepriority;
+                               entry->state     = memorystatus_build_state(p);
+                               entry->user_data = p->p_memstat_userdata;
+                               entry->fds       = p->p_fd->fd_nfiles;
+                       }
+
+                       /*
+                        * Always update the page counts on a kill.
+                        */
+
+                       uint32_t pages              = 0;
+                       uint32_t max_pages_lifetime = 0;
+                       uint32_t purgeable_pages    = 0;
+
+                       memorystatus_get_task_page_counts(p->task, &pages, &max_pages_lifetime, &purgeable_pages);
+                       entry->pages              = (uint64_t)pages;
+                       entry->max_pages_lifetime = (uint64_t)max_pages_lifetime;
+                       entry->purgeable_pages    = (uint64_t)purgeable_pages;
+
+                       uint64_t internal_pages                        = 0;
+                       uint64_t internal_compressed_pages             = 0;
+                       uint64_t purgeable_nonvolatile_pages           = 0;
+                       uint64_t purgeable_nonvolatile_compressed_pages = 0;
+                       uint64_t alternate_accounting_pages            = 0;
+                       uint64_t alternate_accounting_compressed_pages = 0;
+                       uint64_t iokit_mapped_pages                    = 0;
+                       uint64_t page_table_pages                      = 0;
+
+                       memorystatus_get_task_phys_footprint_page_counts(p->task, &internal_pages, &internal_compressed_pages,
+                           &purgeable_nonvolatile_pages, &purgeable_nonvolatile_compressed_pages,
+                           &alternate_accounting_pages, &alternate_accounting_compressed_pages,
+                           &iokit_mapped_pages, &page_table_pages);
+
+                       entry->jse_internal_pages = internal_pages;
+                       entry->jse_internal_compressed_pages = internal_compressed_pages;
+                       entry->jse_purgeable_nonvolatile_pages = purgeable_nonvolatile_pages;
+                       entry->jse_purgeable_nonvolatile_compressed_pages = purgeable_nonvolatile_compressed_pages;
+                       entry->jse_alternate_accounting_pages = alternate_accounting_pages;
+                       entry->jse_alternate_accounting_compressed_pages = alternate_accounting_compressed_pages;
+                       entry->jse_iokit_mapped_pages = iokit_mapped_pages;
+                       entry->jse_page_table_pages = page_table_pages;
+
+                       uint64_t region_count = 0;
+                       memorystatus_get_task_memory_region_count(p->task, &region_count);
+                       entry->jse_memory_region_count = region_count;
+
+                       goto exit;
+               }
+       }
+
+       if (entry == NULL) {
+               /*
+                * The entry was not found in the snapshot, so the process must have
+                * launched after the snapshot was initialized.
+                * Let's try to append the new entry.
+                */
+               if (memorystatus_jetsam_snapshot_count < memorystatus_jetsam_snapshot_max) {
+                       /*
+                        * A populated snapshot buffer exists
+                        * and there is room to init a new entry.
+                        */
+                       assert(memorystatus_jetsam_snapshot_count == snapshot->entry_count);
+
+                       unsigned int next = memorystatus_jetsam_snapshot_count;
+
+                       if (memorystatus_init_jetsam_snapshot_entry_locked(p, &snapshot_list[next], (snapshot->js_gencount)) == TRUE) {
+                               entry = &snapshot_list[next];
+                               entry->killed       = kill_cause;
+                               entry->jse_killtime = killtime;
+
+                               snapshot->entry_count = ++next;
+                               memorystatus_jetsam_snapshot_count = next;
+
+                               if (memorystatus_jetsam_snapshot_count >= memorystatus_jetsam_snapshot_max) {
+                                       /*
+                                        * We just used the last slot in the snapshot buffer.
+                                        * We only want to log it once... so we do it here
+                                        * when we notice we've hit the max.
+                                        */
+                                       printf("memorystatus: WARNING snapshot buffer is full, count %d\n",
+                                           memorystatus_jetsam_snapshot_count);
+                               }
                        }
-                       memorystatus_jetsam_snapshot_list[i].killed = kill_cause;
-                       return;
                }
        }
+
+exit:
+       if (entry == NULL) {
+               /*
+                * If we reach here, the snapshot buffer could not be updated.
+                * Most likely, the buffer is full, in which case we would have
+                * logged a warning in the previous call.
+                *
+                * For now, we will stop appending snapshot entries.
+                * When the buffer is consumed, the snapshot state will reset.
+                */
+
+               MEMORYSTATUS_DEBUG(4, "memorystatus_update_jetsam_snapshot_entry_locked: failed to update pid %d, priority %d, count %d\n",
+                   p->p_pid, p->p_memstat_effectivepriority, memorystatus_jetsam_snapshot_count);
+       }
+
+       return;
 }
 
-void memorystatus_pages_update(unsigned int pages_avail)
+#if CONFIG_JETSAM
+void
+memorystatus_pages_update(unsigned int pages_avail)
 {
        memorystatus_available_pages = pages_avail;
 
 #if VM_PRESSURE_EVENTS
        /*
         * Since memorystatus_available_pages changes, we should
-        * re-evaluate the pressure levels on the system and 
+        * re-evaluate the pressure levels on the system and
         * check if we need to wake the pressure thread.
         * We also update memorystatus_level in that routine.
-        */ 
+        */
        vm_pressure_response();
 
        if (memorystatus_available_pages <= memorystatus_available_pages_pressure) {
-
                if (memorystatus_hwm_candidates || (memorystatus_available_pages <= memorystatus_available_pages_critical)) {
                        memorystatus_thread_wake();
                }
        }
+#if CONFIG_FREEZE
+       /*
+        * We can't grab the freezer_mutex here even though that synchronization would be correct to inspect
+        * the # of frozen processes and wakeup the freezer thread. Reason being that we come here into this
+        * code with (possibly) the page-queue locks held and preemption disabled. So trying to grab a mutex here
+        * will result in the "mutex with preemption disabled" panic.
+        */
+
+       if (memorystatus_freeze_thread_should_run() == TRUE) {
+               /*
+                * The freezer thread is usually woken up by some user-space call i.e. pid_hibernate(any process).
+                * That trigger isn't invoked often enough and so we are enabling this explicit wakeup here.
+                */
+               if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                       thread_wakeup((event_t)&memorystatus_freeze_wakeup);
+               }
+       }
+#endif /* CONFIG_FREEZE */
+
 #else /* VM_PRESSURE_EVENTS */
 
        boolean_t critical, delta;
-        
+
        if (!memorystatus_delta) {
-           return;
+               return;
        }
-       
+
        critical = (pages_avail < memorystatus_available_pages_critical) ? TRUE : FALSE;
-       delta = ((pages_avail >= (memorystatus_available_pages + memorystatus_delta)) 
-                || (memorystatus_available_pages >= (pages_avail + memorystatus_delta))) ? TRUE : FALSE;
-        
+       delta = ((pages_avail >= (memorystatus_available_pages + memorystatus_delta))
+           || (memorystatus_available_pages >= (pages_avail + memorystatus_delta))) ? TRUE : FALSE;
+
        if (critical || delta) {
-               memorystatus_level = memorystatus_available_pages * 100 / atop_64(max_mem);
+               unsigned int total_pages;
+
+               total_pages = (unsigned int) atop_64(max_mem);
+#if CONFIG_SECLUDED_MEMORY
+               total_pages -= vm_page_secluded_count;
+#endif /* CONFIG_SECLUDED_MEMORY */
+               memorystatus_level = memorystatus_available_pages * 100 / total_pages;
                memorystatus_thread_wake();
        }
 #endif /* VM_PRESSURE_EVENTS */
 }
+#endif /* CONFIG_JETSAM */
 
 static boolean_t
-memorystatus_init_jetsam_snapshot_entry_locked(proc_t p, memorystatus_jetsam_snapshot_entry_t *entry)
-{      
+memorystatus_init_jetsam_snapshot_entry_locked(proc_t p, memorystatus_jetsam_snapshot_entry_t *entry, uint64_t gencount)
+{
        clock_sec_t                     tv_sec;
        clock_usec_t                    tv_usec;
+       uint32_t pages = 0;
+       uint32_t max_pages_lifetime = 0;
+       uint32_t purgeable_pages = 0;
+       uint64_t internal_pages                         = 0;
+       uint64_t internal_compressed_pages              = 0;
+       uint64_t purgeable_nonvolatile_pages            = 0;
+       uint64_t purgeable_nonvolatile_compressed_pages = 0;
+       uint64_t alternate_accounting_pages             = 0;
+       uint64_t alternate_accounting_compressed_pages  = 0;
+       uint64_t iokit_mapped_pages                     = 0;
+       uint64_t page_table_pages                       = 0;
+       uint64_t region_count                           = 0;
+       uint64_t cids[COALITION_NUM_TYPES];
 
        memset(entry, 0, sizeof(memorystatus_jetsam_snapshot_entry_t));
-       
+
        entry->pid = p->p_pid;
-       strlcpy(&entry->name[0], p->p_comm, MAXCOMLEN+1);
+       strlcpy(&entry->name[0], p->p_name, sizeof(entry->name));
        entry->priority = p->p_memstat_effectivepriority;
-       memorystatus_get_task_page_counts(p->task, &entry->pages, &entry->max_pages, &entry->max_pages_lifetime, &entry->purgeable_pages);
-       entry->state = memorystatus_build_state(p);
+
+       memorystatus_get_task_page_counts(p->task, &pages, &max_pages_lifetime, &purgeable_pages);
+       entry->pages              = (uint64_t)pages;
+       entry->max_pages_lifetime = (uint64_t)max_pages_lifetime;
+       entry->purgeable_pages    = (uint64_t)purgeable_pages;
+
+       memorystatus_get_task_phys_footprint_page_counts(p->task, &internal_pages, &internal_compressed_pages,
+           &purgeable_nonvolatile_pages, &purgeable_nonvolatile_compressed_pages,
+           &alternate_accounting_pages, &alternate_accounting_compressed_pages,
+           &iokit_mapped_pages, &page_table_pages);
+
+       entry->jse_internal_pages = internal_pages;
+       entry->jse_internal_compressed_pages = internal_compressed_pages;
+       entry->jse_purgeable_nonvolatile_pages = purgeable_nonvolatile_pages;
+       entry->jse_purgeable_nonvolatile_compressed_pages = purgeable_nonvolatile_compressed_pages;
+       entry->jse_alternate_accounting_pages = alternate_accounting_pages;
+       entry->jse_alternate_accounting_compressed_pages = alternate_accounting_compressed_pages;
+       entry->jse_iokit_mapped_pages = iokit_mapped_pages;
+       entry->jse_page_table_pages = page_table_pages;
+
+       memorystatus_get_task_memory_region_count(p->task, &region_count);
+       entry->jse_memory_region_count = region_count;
+
+       entry->state     = memorystatus_build_state(p);
        entry->user_data = p->p_memstat_userdata;
        memcpy(&entry->uuid[0], &p->p_uuid[0], sizeof(p->p_uuid));
-       entry->fds = p->p_fd->fd_nfiles;
+       entry->fds       = p->p_fd->fd_nfiles;
 
        absolutetime_to_microtime(get_task_cpu_time(p->task), &tv_sec, &tv_usec);
-       entry->cpu_time.tv_sec = tv_sec;
-       entry->cpu_time.tv_usec = tv_usec;
+       entry->cpu_time.tv_sec = (int64_t)tv_sec;
+       entry->cpu_time.tv_usec = (int64_t)tv_usec;
+
+       assert(p->p_stats != NULL);
+       entry->jse_starttime =  p->p_stats->ps_start;   /* abstime process started */
+       entry->jse_killtime = 0;                        /* abstime jetsam chose to kill process */
+       entry->killed       = 0;                        /* the jetsam kill cause */
+       entry->jse_gencount = gencount;                 /* indicates a pass through jetsam thread, when process was targeted to be killed */
+
+       entry->jse_idle_delta = p->p_memstat_idle_delta; /* Most recent timespan spent in idle-band */
+
+#if CONFIG_FREEZE
+       entry->jse_thaw_count = p->p_memstat_thaw_count;
+#else /* CONFIG_FREEZE */
+       entry->jse_thaw_count = 0;
+#endif /* CONFIG_FREEZE */
+
+       proc_coalitionids(p, cids);
+       entry->jse_coalition_jetsam_id = cids[COALITION_TYPE_JETSAM];
 
-       return TRUE;    
+       return TRUE;
 }
 
 static void
 memorystatus_init_snapshot_vmstats(memorystatus_jetsam_snapshot_t *snapshot)
 {
        kern_return_t kr = KERN_SUCCESS;
-       mach_msg_type_number_t  count = HOST_VM_INFO64_COUNT;
-       vm_statistics64_data_t  vm_stat;
+       mach_msg_type_number_t  count = HOST_VM_INFO64_COUNT;
+       vm_statistics64_data_t  vm_stat;
 
-       if ((kr = host_statistics64(host_self(), HOST_VM_INFO64, (host_info64_t)&vm_stat, &count) != KERN_SUCCESS)) {
+       if ((kr = host_statistics64(host_self(), HOST_VM_INFO64, (host_info64_t)&vm_stat, &count)) != KERN_SUCCESS) {
                printf("memorystatus_init_jetsam_snapshot_stats: host_statistics64 failed with %d\n", kr);
                memset(&snapshot->stats, 0, sizeof(snapshot->stats));
        } else {
-               snapshot->stats.free_pages      = vm_stat.free_count;
-               snapshot->stats.active_pages    = vm_stat.active_count;
-               snapshot->stats.inactive_pages  = vm_stat.inactive_count;
-               snapshot->stats.throttled_pages = vm_stat.throttled_count;
-               snapshot->stats.purgeable_pages = vm_stat.purgeable_count;
-               snapshot->stats.wired_pages     = vm_stat.wire_count;
+               snapshot->stats.free_pages      = vm_stat.free_count;
+               snapshot->stats.active_pages    = vm_stat.active_count;
+               snapshot->stats.inactive_pages  = vm_stat.inactive_count;
+               snapshot->stats.throttled_pages = vm_stat.throttled_count;
+               snapshot->stats.purgeable_pages = vm_stat.purgeable_count;
+               snapshot->stats.wired_pages     = vm_stat.wire_count;
 
                snapshot->stats.speculative_pages = vm_stat.speculative_count;
                snapshot->stats.filebacked_pages  = vm_stat.external_page_count;
@@ -2961,6 +5416,10 @@ memorystatus_init_snapshot_vmstats(memorystatus_jetsam_snapshot_t *snapshot)
                snapshot->stats.compressor_pages  = vm_stat.compressor_page_count;
                snapshot->stats.total_uncompressed_pages_in_compressor = vm_stat.total_uncompressed_pages_in_compressor;
        }
+
+       get_zone_map_size(&snapshot->stats.zone_map_size, &snapshot->stats.zone_map_capacity);
+       get_largest_zone_info(snapshot->stats.largest_zone_name, sizeof(snapshot->stats.largest_zone_name),
+           &snapshot->stats.largest_zone_size);
 }
 
 /*
@@ -2969,7 +5428,8 @@ memorystatus_init_snapshot_vmstats(memorystatus_jetsam_snapshot_t *snapshot)
  * Data can be consumed at any time.
  */
 void
-memorystatus_init_at_boot_snapshot() {
+memorystatus_init_at_boot_snapshot()
+{
        memorystatus_init_snapshot_vmstats(&memorystatus_at_boot_snapshot);
        memorystatus_at_boot_snapshot.entry_count = 0;
        memorystatus_at_boot_snapshot.notification_time = 0;   /* updated when consumed */
@@ -2986,6 +5446,8 @@ memorystatus_init_jetsam_snapshot_locked(memorystatus_jetsam_snapshot_t *od_snap
        memorystatus_jetsam_snapshot_entry_t *snapshot_list = NULL;
        unsigned int snapshot_max = 0;
 
+       LCK_MTX_ASSERT(proc_list_mlock, LCK_MTX_ASSERT_OWNED);
+
        if (od_snapshot) {
                /*
                 * This is an on_demand snapshot
@@ -3002,28 +5464,33 @@ memorystatus_init_jetsam_snapshot_locked(memorystatus_jetsam_snapshot_t *od_snap
                snapshot_max  = memorystatus_jetsam_snapshot_max;
        }
 
+       /*
+        * Init the snapshot header information
+        */
        memorystatus_init_snapshot_vmstats(snapshot);
+       snapshot->snapshot_time = mach_absolute_time();
+       snapshot->notification_time = 0;
+       snapshot->js_gencount = 0;
 
        next_p = memorystatus_get_first_proc_locked(&b, TRUE);
        while (next_p) {
                p = next_p;
                next_p = memorystatus_get_next_proc_locked(&b, p, TRUE);
-               
-               if (FALSE == memorystatus_init_jetsam_snapshot_entry_locked(p, &snapshot_list[i])) {
+
+               if (FALSE == memorystatus_init_jetsam_snapshot_entry_locked(p, &snapshot_list[i], snapshot->js_gencount)) {
                        continue;
                }
-               
+
                MEMORYSTATUS_DEBUG(0, "jetsam snapshot pid %d, uuid = %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
-                       p->p_pid, 
-                       p->p_uuid[0], p->p_uuid[1], p->p_uuid[2], p->p_uuid[3], p->p_uuid[4], p->p_uuid[5], p->p_uuid[6], p->p_uuid[7],
-                       p->p_uuid[8], p->p_uuid[9], p->p_uuid[10], p->p_uuid[11], p->p_uuid[12], p->p_uuid[13], p->p_uuid[14], p->p_uuid[15]);
+                   p->p_pid,
+                   p->p_uuid[0], p->p_uuid[1], p->p_uuid[2], p->p_uuid[3], p->p_uuid[4], p->p_uuid[5], p->p_uuid[6], p->p_uuid[7],
+                   p->p_uuid[8], p->p_uuid[9], p->p_uuid[10], p->p_uuid[11], p->p_uuid[12], p->p_uuid[13], p->p_uuid[14], p->p_uuid[15]);
 
                if (++i == snapshot_max) {
                        break;
-               }       
+               }
        }
 
-       snapshot->snapshot_time = mach_absolute_time();
        snapshot->entry_count = i;
 
        if (!od_snapshot) {
@@ -3034,11 +5501,13 @@ memorystatus_init_jetsam_snapshot_locked(memorystatus_jetsam_snapshot_t *od_snap
 
 #if DEVELOPMENT || DEBUG
 
+#if CONFIG_JETSAM
 static int
-memorystatus_cmd_set_panic_bits(user_addr_t buffer, uint32_t buffer_size) {
+memorystatus_cmd_set_panic_bits(user_addr_t buffer, uint32_t buffer_size)
+{
        int ret;
        memorystatus_jetsam_panic_options_t debug;
-       
+
        if (buffer_size != sizeof(memorystatus_jetsam_panic_options_t)) {
                return EINVAL;
        }
@@ -3047,16 +5516,17 @@ memorystatus_cmd_set_panic_bits(user_addr_t buffer, uint32_t buffer_size) {
        if (ret) {
                return ret;
        }
-       
+
        /* Panic bits match kMemorystatusKilled* enum */
        memorystatus_jetsam_panic_debug = (memorystatus_jetsam_panic_debug & ~debug.mask) | (debug.data & debug.mask);
-       
+
        /* Copyout new value */
        debug.data = memorystatus_jetsam_panic_debug;
        ret = copyout(&debug, buffer, sizeof(memorystatus_jetsam_panic_options_t));
-       
+
        return ret;
 }
+#endif /* CONFIG_JETSAM */
 
 /*
  * Triggers a sort_order on a specified jetsam priority band.
@@ -3064,8 +5534,8 @@ memorystatus_cmd_set_panic_bits(user_addr_t buffer, uint32_t buffer_size) {
  * function.
  */
 static int
-memorystatus_cmd_test_jetsam_sort(int priority, int sort_order) {
-
+memorystatus_cmd_test_jetsam_sort(int priority, int sort_order)
+{
        int error = 0;
 
        unsigned int bucket_index = 0;
@@ -3079,109 +5549,248 @@ memorystatus_cmd_test_jetsam_sort(int priority, int sort_order) {
 
        error = memorystatus_sort_bucket(bucket_index, sort_order);
 
-       return (error);
+       return error;
 }
 
-#endif
+#endif /* DEVELOPMENT || DEBUG */
 
 /*
- * Jetsam a specific process.
+ * Prepare the process to be killed (set state, update snapshot) and kill it.
  */
-static boolean_t 
-memorystatus_kill_specific_process(pid_t victim_pid, uint32_t cause) {
-       boolean_t killed;
-       proc_t p;
+static uint64_t memorystatus_purge_before_jetsam_success = 0;
 
-       /* TODO - add a victim queue and push this into the main jetsam thread */
+static boolean_t
+memorystatus_kill_proc(proc_t p, uint32_t cause, os_reason_t jetsam_reason, boolean_t *killed)
+{
+       pid_t aPid = 0;
+       uint32_t aPid_ep = 0;
 
-       p = proc_find(victim_pid);
-       if (!p) {
-               return FALSE;
+       uint64_t        killtime = 0;
+       clock_sec_t     tv_sec;
+       clock_usec_t    tv_usec;
+       uint32_t        tv_msec;
+       boolean_t       retval = FALSE;
+       uint64_t        num_pages_purged = 0;
+
+       aPid = p->p_pid;
+       aPid_ep = p->p_memstat_effectivepriority;
+
+       if (cause != kMemorystatusKilledVnodes && cause != kMemorystatusKilledZoneMapExhaustion) {
+               /*
+                * Genuine memory pressure and not other (vnode/zone) resource exhaustion.
+                */
+               boolean_t success = FALSE;
+
+               networking_memstatus_callout(p, cause);
+               num_pages_purged = vm_purgeable_purge_task_owned(p->task);
+
+               if (num_pages_purged) {
+                       /*
+                        * We actually purged something and so let's
+                        * check if we need to continue with the kill.
+                        */
+                       if (cause == kMemorystatusKilledHiwat) {
+                               uint64_t footprint_in_bytes = get_task_phys_footprint(p->task);
+                               uint64_t memlimit_in_bytes  = (((uint64_t)p->p_memstat_memlimit) * 1024ULL * 1024ULL);  /* convert MB to bytes */
+                               success = (footprint_in_bytes <= memlimit_in_bytes);
+                       } else {
+                               success = (memorystatus_avail_pages_below_pressure() == FALSE);
+                       }
+
+                       if (success) {
+                               memorystatus_purge_before_jetsam_success++;
+
+                               os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: purged %llu pages from pid %d [%s] and avoided %s\n",
+                                   num_pages_purged, aPid, (*p->p_name ? p->p_name : "unknown"), memorystatus_kill_cause_name[cause]);
+
+                               *killed = FALSE;
+
+                               return TRUE;
+                       }
+               }
        }
 
-       printf("memorystatus: specifically killing pid %d [%s] (%s %d) - memorystatus_available_pages: %d\n", 
-               victim_pid, (p->p_comm ? p->p_comm : "(unknown)"),
-              jetsam_kill_cause_name[cause], p->p_memstat_effectivepriority, memorystatus_available_pages);
+#if CONFIG_JETSAM && (DEVELOPMENT || DEBUG)
+       MEMORYSTATUS_DEBUG(1, "jetsam: %s pid %d [%s] - %lld Mb > 1 (%d Mb)\n",
+           (memorystatus_jetsam_policy & kPolicyDiagnoseActive) ? "suspending": "killing",
+           aPid, (*p->p_name ? p->p_name : "unknown"),
+           (footprint_in_bytes / (1024ULL * 1024ULL)),                 /* converted bytes to MB */
+           p->p_memstat_memlimit);
+#endif /* CONFIG_JETSAM && (DEVELOPMENT || DEBUG) */
 
-       proc_list_lock();
+       killtime = mach_absolute_time();
+       absolutetime_to_microtime(killtime, &tv_sec, &tv_usec);
+       tv_msec = tv_usec / 1000;
 
-       if (memorystatus_jetsam_snapshot_count == 0) {
-               memorystatus_init_jetsam_snapshot_locked(NULL,0);
+#if CONFIG_JETSAM && (DEVELOPMENT || DEBUG)
+       if (memorystatus_jetsam_policy & kPolicyDiagnoseActive) {
+               if (cause == kMemorystatusKilledHiwat) {
+                       MEMORYSTATUS_DEBUG(1, "jetsam: suspending pid %d [%s] for diagnosis - memorystatus_available_pages: %d\n",
+                           aPid, (*p->p_name ? p->p_name: "(unknown)"), memorystatus_available_pages);
+               } else {
+                       int activeProcess = p->p_memstat_state & P_MEMSTAT_FOREGROUND;
+                       if (activeProcess) {
+                               MEMORYSTATUS_DEBUG(1, "jetsam: suspending pid %d [%s] (active) for diagnosis - memorystatus_available_pages: %d\n",
+                                   aPid, (*p->p_name ? p->p_name: "(unknown)"), memorystatus_available_pages);
+
+                               if (memorystatus_jetsam_policy & kPolicyDiagnoseFirst) {
+                                       jetsam_diagnostic_suspended_one_active_proc = 1;
+                                       printf("jetsam: returning after suspending first active proc - %d\n", aPid);
+                               }
+                       }
+               }
+
+               proc_list_lock();
+               /* This diagnostic code is going away soon. Ignore the kMemorystatusInvalid cause here. */
+               memorystatus_update_jetsam_snapshot_entry_locked(p, kMemorystatusInvalid, killtime);
+               proc_list_unlock();
+
+               p->p_memstat_state |= P_MEMSTAT_DIAG_SUSPENDED;
+
+               if (p) {
+                       task_suspend(p->task);
+                       *killed = TRUE;
+               }
+       } else
+#endif /* CONFIG_JETSAM && (DEVELOPMENT || DEBUG) */
+       {
+               proc_list_lock();
+               memorystatus_update_jetsam_snapshot_entry_locked(p, cause, killtime);
+               proc_list_unlock();
+
+               char kill_reason_string[128];
+
+               if (cause == kMemorystatusKilledHiwat) {
+                       strlcpy(kill_reason_string, "killing_highwater_process", 128);
+               } else {
+                       if (aPid_ep == JETSAM_PRIORITY_IDLE) {
+                               strlcpy(kill_reason_string, "killing_idle_process", 128);
+                       } else {
+                               strlcpy(kill_reason_string, "killing_top_process", 128);
+                       }
+               }
+
+               os_log_with_startup_serial(OS_LOG_DEFAULT, "%lu.%03d memorystatus: %s pid %d [%s] (%s %d) - memorystatus_available_pages: %llu\n",
+                   (unsigned long)tv_sec, tv_msec, kill_reason_string,
+                   aPid, (*p->p_name ? p->p_name : "unknown"),
+                   memorystatus_kill_cause_name[cause], aPid_ep, (uint64_t)memorystatus_available_pages);
+
+               /*
+                * memorystatus_do_kill drops a reference, so take another one so we can
+                * continue to use this exit reason even after memorystatus_do_kill()
+                * returns
+                */
+               os_reason_ref(jetsam_reason);
+
+               retval = memorystatus_do_kill(p, cause, jetsam_reason);
+
+               *killed = retval;
        }
 
-       memorystatus_update_jetsam_snapshot_entry_locked(p, cause);
-       proc_list_unlock();
-       
-       killed = memorystatus_do_kill(p, cause);
-       proc_rele(p);
-       
-       return killed;
+       return retval;
 }
 
 /*
  * Jetsam the first process in the queue.
  */
 static boolean_t
-memorystatus_kill_top_process(boolean_t any, boolean_t sort_flag, uint32_t cause, int32_t *priority, uint32_t *errors)
+memorystatus_kill_top_process(boolean_t any, boolean_t sort_flag, uint32_t cause, os_reason_t jetsam_reason,
+    int32_t *priority, uint32_t *errors)
 {
        pid_t aPid;
        proc_t p = PROC_NULL, next_p = PROC_NULL;
-       boolean_t new_snapshot = FALSE, killed = FALSE;
-       int kill_count = 0;
+       boolean_t new_snapshot = FALSE, force_new_snapshot = FALSE, killed = FALSE, freed_mem = FALSE;
        unsigned int i = 0;
        uint32_t aPid_ep;
+       int32_t         local_max_kill_prio = JETSAM_PRIORITY_IDLE;
 
 #ifndef CONFIG_FREEZE
 #pragma unused(any)
 #endif
-       
+
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM) | DBG_FUNC_START,
-               memorystatus_available_pages, 0, 0, 0, 0);
+           memorystatus_available_pages, 0, 0, 0, 0);
+
+
+#if CONFIG_JETSAM
+       if (sort_flag == TRUE) {
+               (void)memorystatus_sort_bucket(JETSAM_PRIORITY_FOREGROUND, JETSAM_SORT_DEFAULT);
+       }
+
+       local_max_kill_prio = max_kill_priority;
+
+       force_new_snapshot = FALSE;
 
+#else /* CONFIG_JETSAM */
 
        if (sort_flag == TRUE) {
-               (void)memorystatus_sort_bucket(JETSAM_PRIORITY_FOREGROUND, JETSAM_SORT_DEFAULT);
+               (void)memorystatus_sort_bucket(JETSAM_PRIORITY_IDLE, JETSAM_SORT_DEFAULT);
+       }
+
+       /*
+        * On macos, we currently only have 2 reasons to be here:
+        *
+        * kMemorystatusKilledZoneMapExhaustion
+        * AND
+        * kMemorystatusKilledVMCompressorSpaceShortage
+        *
+        * If we are here because of kMemorystatusKilledZoneMapExhaustion, we will consider
+        * any and all processes as eligible kill candidates since we need to avoid a panic.
+        *
+        * Since this function can be called async. it is harder to toggle the max_kill_priority
+        * value before and after a call. And so we use this local variable to set the upper band
+        * on the eligible kill bands.
+        */
+       if (cause == kMemorystatusKilledZoneMapExhaustion) {
+               local_max_kill_prio = JETSAM_PRIORITY_MAX;
+       } else {
+               local_max_kill_prio = max_kill_priority;
        }
 
+       /*
+        * And, because we are here under extreme circumstances, we force a snapshot even for
+        * IDLE kills.
+        */
+       force_new_snapshot = TRUE;
+
+#endif /* CONFIG_JETSAM */
+
        proc_list_lock();
 
        next_p = memorystatus_get_first_proc_locked(&i, TRUE);
-       while (next_p) {
+       while (next_p && (next_p->p_memstat_effectivepriority <= local_max_kill_prio)) {
 #if DEVELOPMENT || DEBUG
-               int activeProcess;
                int procSuspendedForDiagnosis;
 #endif /* DEVELOPMENT || DEBUG */
-        
+
                p = next_p;
                next_p = memorystatus_get_next_proc_locked(&i, p, TRUE);
-               
+
 #if DEVELOPMENT || DEBUG
-               activeProcess = p->p_memstat_state & P_MEMSTAT_FOREGROUND;
                procSuspendedForDiagnosis = p->p_memstat_state & P_MEMSTAT_DIAG_SUSPENDED;
 #endif /* DEVELOPMENT || DEBUG */
-               
+
                aPid = p->p_pid;
                aPid_ep = p->p_memstat_effectivepriority;
 
                if (p->p_memstat_state & (P_MEMSTAT_ERROR | P_MEMSTAT_TERMINATED)) {
-                       continue;
+                       continue;   /* with lock held */
                }
-                   
-#if DEVELOPMENT || DEBUG
+
+#if CONFIG_JETSAM && (DEVELOPMENT || DEBUG)
                if ((memorystatus_jetsam_policy & kPolicyDiagnoseActive) && procSuspendedForDiagnosis) {
                        printf("jetsam: continuing after ignoring proc suspended already for diagnosis - %d\n", aPid);
                        continue;
                }
-#endif /* DEVELOPMENT || DEBUG */
+#endif /* CONFIG_JETSAM && (DEVELOPMENT || DEBUG) */
 
-               if (cause == kMemorystatusKilledVnodes)
-               {
+               if (cause == kMemorystatusKilledVnodes) {
                        /*
                         * If the system runs out of vnodes, we systematically jetsam
                         * processes in hopes of stumbling onto a vnode gain that helps
                         * the system recover.  The process that happens to trigger
-                        * this path has no known relationship to the vnode consumption.
-                        * We attempt to safeguard that process e.g: do not jetsam it.
+                        * this path has no known relationship to the vnode shortage.
+                        * Deadlock avoidance: attempt to safeguard the caller.
                         */
 
                        if (p == current_proc()) {
@@ -3192,135 +5801,110 @@ memorystatus_kill_top_process(boolean_t any, boolean_t sort_flag, uint32_t cause
 
 #if CONFIG_FREEZE
                boolean_t skip;
-               boolean_t reclaim_proc = !(p->p_memstat_state & (P_MEMSTAT_LOCKED | P_MEMSTAT_NORECLAIM));
+               boolean_t reclaim_proc = !(p->p_memstat_state & P_MEMSTAT_LOCKED);
                if (any || reclaim_proc) {
                        skip = FALSE;
                } else {
                        skip = TRUE;
                }
-                       
+
                if (skip) {
                        continue;
                } else
 #endif
                {
-                       /*
-                        * Capture a snapshot if none exists and:
-                        * - priority was not requested (this is something other than an ambient kill)
-                        * - the priority was requested *and* the targeted process is not at idle priority
-                        */
-                       if ((memorystatus_jetsam_snapshot_count == 0) && 
-                               (memorystatus_idle_snapshot || ((!priority) || (priority && (*priority != JETSAM_PRIORITY_IDLE))))) {
-                               memorystatus_init_jetsam_snapshot_locked(NULL,0);
-                               new_snapshot = TRUE;
-                       }
-                       
-                       /* 
-                        * Mark as terminated so that if exit1() indicates success, but the process (for example)
-                        * is blocked in task_exception_notify(), it'll be skipped if encountered again - see 
-                        * <rdar://problem/13553476>. This is cheaper than examining P_LEXIT, which requires the 
-                        * acquisition of the proc lock.
+                       if (proc_ref_locked(p) == p) {
+                               /*
+                                * Mark as terminated so that if exit1() indicates success, but the process (for example)
+                                * is blocked in task_exception_notify(), it'll be skipped if encountered again - see
+                                * <rdar://problem/13553476>. This is cheaper than examining P_LEXIT, which requires the
+                                * acquisition of the proc lock.
+                                */
+                               p->p_memstat_state |= P_MEMSTAT_TERMINATED;
+                       } else {
+                               /*
+                                * We need to restart the search again because
+                                * proc_ref_locked _can_ drop the proc_list lock
+                                * and we could have lost our stored next_p via
+                                * an exit() on another core.
+                                */
+                               i = 0;
+                               next_p = memorystatus_get_first_proc_locked(&i, TRUE);
+                               continue;
+                       }
+
+                       /*
+                        * Capture a snapshot if none exists and:
+                        * - we are forcing a new snapshot creation, either because:
+                        *      - on a particular platform we need these snapshots every time, OR
+                        *      - a boot-arg/embedded device tree property has been set.
+                        * - priority was not requested (this is something other than an ambient kill)
+                        * - the priority was requested *and* the targeted process is not at idle priority
                         */
-                       p->p_memstat_state |= P_MEMSTAT_TERMINATED;
-                       
-#if DEVELOPMENT || DEBUG
-                       if ((memorystatus_jetsam_policy & kPolicyDiagnoseActive) && activeProcess) {
-                               MEMORYSTATUS_DEBUG(1, "jetsam: suspending pid %d [%s] (active) for diagnosis - memory_status_level: %d\n",
-                                       aPid, (p->p_comm ? p->p_comm: "(unknown)"), memorystatus_level);
-                               memorystatus_update_jetsam_snapshot_entry_locked(p, kMemorystatusKilledDiagnostic);
-                               p->p_memstat_state |= P_MEMSTAT_DIAG_SUSPENDED;
-                               if (memorystatus_jetsam_policy & kPolicyDiagnoseFirst) {
-                                       jetsam_diagnostic_suspended_one_active_proc = 1;
-                                       printf("jetsam: returning after suspending first active proc - %d\n", aPid);
-                               }
-                               
-                               p = proc_ref_locked(p);
-                               proc_list_unlock();
-                               if (p) {
-                                       task_suspend(p->task);
+                       if ((memorystatus_jetsam_snapshot_count == 0) &&
+                           (force_new_snapshot || memorystatus_idle_snapshot || ((!priority) || (priority && (aPid_ep != JETSAM_PRIORITY_IDLE))))) {
+                               memorystatus_init_jetsam_snapshot_locked(NULL, 0);
+                               new_snapshot = TRUE;
+                       }
+
+                       proc_list_unlock();
+
+                       freed_mem = memorystatus_kill_proc(p, cause, jetsam_reason, &killed); /* purged and/or killed 'p' */
+                       /* Success? */
+                       if (freed_mem) {
+                               if (killed) {
                                        if (priority) {
                                                *priority = aPid_ep;
                                        }
-                                       proc_rele(p);
-                                       killed = TRUE;
-                               }
-                               
-                               goto exit;
-                       } else
-#endif /* DEVELOPMENT || DEBUG */
-                       {
-                               /* Shift queue, update stats */
-                               memorystatus_update_jetsam_snapshot_entry_locked(p, cause);
-
-                               if (proc_ref_locked(p) == p) {
-                                       proc_list_unlock();
-                                       printf("memorystatus: %s %d [%s] (%s %d) - memorystatus_available_pages: %d\n",
-                                           ((aPid_ep == JETSAM_PRIORITY_IDLE) ?
-                                           "idle exiting pid" : "jetsam killing pid"),
-                                           aPid, (p->p_comm ? p->p_comm : "(unknown)"),
-                                              jetsam_kill_cause_name[cause], aPid_ep, memorystatus_available_pages);
-
-                                       killed = memorystatus_do_kill(p, cause);
-
-                                       /* Success? */
-                                       if (killed) {
-                                               if (priority) {
-                                                       *priority = aPid_ep;
-                                               }
-                                               proc_rele(p);
-                                               kill_count++;
-                                               goto exit;
-                                       }
-                               
-                                       /*
-                                        * Failure - first unwind the state,
-                                        * then fall through to restart the search.
-                                        */
+                               } else {
+                                       /* purged */
                                        proc_list_lock();
-                                       proc_rele_locked(p);
                                        p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
-                                       p->p_memstat_state |= P_MEMSTAT_ERROR;
-                                       *errors += 1;
+                                       proc_list_unlock();
                                }
-                               
-                               /*
-                                * Failure - restart the search.
-                                *
-                                * We might have raced with "p" exiting on another core, resulting in no
-                                * ref on "p".  Or, we may have failed to kill "p".
-                                *
-                                * Either way, we fall thru to here, leaving the proc in the
-                                * P_MEMSTAT_TERMINATED state.
-                                *
-                                * And, we hold the the proc_list_lock at this point.
-                                */
-
-                               i = 0;
-                               next_p = memorystatus_get_first_proc_locked(&i, TRUE);
+                               proc_rele(p);
+                               goto exit;
                        }
+
+                       /*
+                        * Failure - first unwind the state,
+                        * then fall through to restart the search.
+                        */
+                       proc_list_lock();
+                       proc_rele_locked(p);
+                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
+                       p->p_memstat_state |= P_MEMSTAT_ERROR;
+                       *errors += 1;
+
+                       i = 0;
+                       next_p = memorystatus_get_first_proc_locked(&i, TRUE);
                }
        }
-       
+
        proc_list_unlock();
-       
+
 exit:
+       os_reason_free(jetsam_reason);
+
        /* Clear snapshot if freshly captured and no target was found */
        if (new_snapshot && !killed) {
-           memorystatus_jetsam_snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
+               proc_list_lock();
+               memorystatus_jetsam_snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
+               proc_list_unlock();
        }
-       
+
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM) | DBG_FUNC_END,
-                             memorystatus_available_pages, killed ? aPid : 0, kill_count, 0, 0);
+           memorystatus_available_pages, killed ? aPid : 0, 0, 0, 0);
 
        return killed;
 }
 
 /*
- * Jetsam aggressively 
+ * Jetsam aggressively
  */
 static boolean_t
-memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr_count, int32_t priority_max, 
-                                        uint32_t *errors)
+memorystatus_kill_top_process_aggressive(uint32_t cause, int aggr_count,
+    int32_t priority_max, uint32_t *errors)
 {
        pid_t aPid;
        proc_t p = PROC_NULL, next_p = PROC_NULL;
@@ -3328,11 +5912,22 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
        int kill_count = 0;
        unsigned int i = 0;
        int32_t aPid_ep = 0;
-
-#pragma unused(any)
+       unsigned int memorystatus_level_snapshot = 0;
+       uint64_t killtime = 0;
+       clock_sec_t     tv_sec;
+       clock_usec_t    tv_usec;
+       uint32_t        tv_msec;
+       os_reason_t jetsam_reason = OS_REASON_NULL;
 
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM) | DBG_FUNC_START,
-               memorystatus_available_pages, priority_max, 0, 0, 0);
+           memorystatus_available_pages, priority_max, 0, 0, 0);
+
+       memorystatus_sort_bucket(JETSAM_PRIORITY_FOREGROUND, JETSAM_SORT_DEFAULT);
+
+       jetsam_reason = os_reason_create(OS_REASON_JETSAM, cause);
+       if (jetsam_reason == OS_REASON_NULL) {
+               printf("memorystatus_kill_top_process_aggressive: failed to allocate exit reason\n");
+       }
 
        proc_list_lock();
 
@@ -3343,20 +5938,21 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
                int procSuspendedForDiagnosis;
 #endif /* DEVELOPMENT || DEBUG */
 
-               if ((unsigned int)(next_p->p_memstat_effectivepriority) != i) {
-
+               if (((next_p->p_listflag & P_LIST_EXITED) != 0) ||
+                   ((unsigned int)(next_p->p_memstat_effectivepriority) != i)) {
                        /*
-                        * We have raced with next_p running on another core, as it has
-                        * moved to a different jetsam priority band.  This means we have
-                        * lost our place in line while traversing the jetsam list.  We
+                        * We have raced with next_p running on another core.
+                        * It may be exiting or it may have moved to a different
+                        * jetsam priority band.  This means we have lost our
+                        * place in line while traversing the jetsam list.  We
                         * attempt to recover by rewinding to the beginning of the band
                         * we were already traversing.  By doing this, we do not guarantee
                         * that no process escapes this aggressive march, but we can make
                         * skipping an entire range of processes less likely. (PR-21069019)
                         */
 
-                       MEMORYSTATUS_DEBUG(1, "memorystatus: aggressive%d: rewinding %s moved from band %d --> %d\n",
-                              aggr_count, next_p->p_comm, i, next_p->p_memstat_effectivepriority);
+                       MEMORYSTATUS_DEBUG(1, "memorystatus: aggressive%d: rewinding band %d, %s(%d) moved or exiting.\n",
+                           aggr_count, i, (*next_p->p_name ? next_p->p_name : "unknown"), next_p->p_pid);
 
                        next_p = memorystatus_get_first_proc_locked(&i, TRUE);
                        continue;
@@ -3366,53 +5962,57 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
                next_p = memorystatus_get_next_proc_locked(&i, p, TRUE);
 
                if (p->p_memstat_effectivepriority > priority_max) {
-                       /* 
+                       /*
                         * Bail out of this killing spree if we have
                         * reached beyond the priority_max jetsam band.
-                        * That is, we kill up to and through the 
+                        * That is, we kill up to and through the
                         * priority_max jetsam band.
                         */
                        proc_list_unlock();
                        goto exit;
                }
-               
+
 #if DEVELOPMENT || DEBUG
                activeProcess = p->p_memstat_state & P_MEMSTAT_FOREGROUND;
                procSuspendedForDiagnosis = p->p_memstat_state & P_MEMSTAT_DIAG_SUSPENDED;
 #endif /* DEVELOPMENT || DEBUG */
-               
+
                aPid = p->p_pid;
                aPid_ep = p->p_memstat_effectivepriority;
 
                if (p->p_memstat_state & (P_MEMSTAT_ERROR | P_MEMSTAT_TERMINATED)) {
                        continue;
                }
-                   
-#if DEVELOPMENT || DEBUG
+
+#if CONFIG_JETSAM && (DEVELOPMENT || DEBUG)
                if ((memorystatus_jetsam_policy & kPolicyDiagnoseActive) && procSuspendedForDiagnosis) {
                        printf("jetsam: continuing after ignoring proc suspended already for diagnosis - %d\n", aPid);
                        continue;
                }
-#endif /* DEVELOPMENT || DEBUG */
+#endif /* CONFIG_JETSAM && (DEVELOPMENT || DEBUG) */
 
                /*
                 * Capture a snapshot if none exists.
                 */
                if (memorystatus_jetsam_snapshot_count == 0) {
-                       memorystatus_init_jetsam_snapshot_locked(NULL,0);
+                       memorystatus_init_jetsam_snapshot_locked(NULL, 0);
                        new_snapshot = TRUE;
                }
-                       
-               /* 
+
+               /*
                 * Mark as terminated so that if exit1() indicates success, but the process (for example)
-                * is blocked in task_exception_notify(), it'll be skipped if encountered again - see 
-                * <rdar://problem/13553476>. This is cheaper than examining P_LEXIT, which requires the 
+                * is blocked in task_exception_notify(), it'll be skipped if encountered again - see
+                * <rdar://problem/13553476>. This is cheaper than examining P_LEXIT, which requires the
                 * acquisition of the proc lock.
                 */
                p->p_memstat_state |= P_MEMSTAT_TERMINATED;
-                       
+
+               killtime = mach_absolute_time();
+               absolutetime_to_microtime(killtime, &tv_sec, &tv_usec);
+               tv_msec = tv_usec / 1000;
+
                /* Shift queue, update stats */
-               memorystatus_update_jetsam_snapshot_entry_locked(p, cause);
+               memorystatus_update_jetsam_snapshot_entry_locked(p, cause, killtime);
 
                /*
                 * In order to kill the target process, we will drop the proc_list_lock.
@@ -3426,28 +6026,36 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
                                while (next_p && (proc_ref_locked(next_p) != next_p)) {
                                        proc_t temp_p;
 
-                                        /*
-                                         * We must have raced with next_p exiting on another core.
-                                         * Recover by getting the next eligible process in the band.
-                                         */
+                                       /*
+                                        * We must have raced with next_p exiting on another core.
+                                        * Recover by getting the next eligible process in the band.
+                                        */
 
                                        MEMORYSTATUS_DEBUG(1, "memorystatus: aggressive%d: skipping %d [%s] (exiting?)\n",
-                                              aggr_count, next_p->p_pid, (next_p->p_comm ? next_p->p_comm : "(unknown)"));
+                                           aggr_count, next_p->p_pid, (*next_p->p_name ? next_p->p_name : "(unknown)"));
 
                                        temp_p = next_p;
                                        next_p = memorystatus_get_next_proc_locked(&i, temp_p, TRUE);
-                                }
+                               }
                        }
                        proc_list_unlock();
 
-                       printf("memorystatus: aggressive%d: %s %d [%s] (%s %d) - memorystatus_available_pages: %d\n",
-                              aggr_count,
-                              ((aPid_ep == JETSAM_PRIORITY_IDLE) ? "idle exiting pid" : "jetsam killing pid"),
-                              aPid, (p->p_comm ? p->p_comm : "(unknown)"),
-                              jetsam_kill_cause_name[cause], aPid_ep, memorystatus_available_pages);
+                       printf("%lu.%03d memorystatus: %s%d pid %d [%s] (%s %d) - memorystatus_available_pages: %llu\n",
+                           (unsigned long)tv_sec, tv_msec,
+                           ((aPid_ep == JETSAM_PRIORITY_IDLE) ? "killing_idle_process_aggressive" : "killing_top_process_aggressive"),
+                           aggr_count, aPid, (*p->p_name ? p->p_name : "unknown"),
+                           memorystatus_kill_cause_name[cause], aPid_ep, (uint64_t)memorystatus_available_pages);
+
+                       memorystatus_level_snapshot = memorystatus_level;
+
+                       /*
+                        * memorystatus_do_kill() drops a reference, so take another one so we can
+                        * continue to use this exit reason even after memorystatus_do_kill()
+                        * returns.
+                        */
+                       os_reason_ref(jetsam_reason);
+                       killed = memorystatus_do_kill(p, cause, jetsam_reason);
 
-                       killed = memorystatus_do_kill(p, cause);
-                               
                        /* Success? */
                        if (killed) {
                                proc_rele(p);
@@ -3455,16 +6063,27 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
                                p = NULL;
                                killed = FALSE;
 
-                               /* 
+                               /*
                                 * Continue the killing spree.
                                 */
                                proc_list_lock();
                                if (next_p) {
                                        proc_rele_locked(next_p);
                                }
+
+                               if (aPid_ep == JETSAM_PRIORITY_FOREGROUND && memorystatus_aggressive_jetsam_lenient == TRUE) {
+                                       if (memorystatus_level > memorystatus_level_snapshot && ((memorystatus_level - memorystatus_level_snapshot) >= AGGRESSIVE_JETSAM_LENIENT_MODE_THRESHOLD)) {
+#if DEVELOPMENT || DEBUG
+                                               printf("Disabling Lenient mode after one-time deployment.\n");
+#endif /* DEVELOPMENT || DEBUG */
+                                               memorystatus_aggressive_jetsam_lenient = FALSE;
+                                               break;
+                                       }
+                               }
+
                                continue;
                        }
-                                       
+
                        /*
                         * Failure - first unwind the state,
                         * then fall through to restart the search.
@@ -3487,7 +6106,7 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
                 * We might have raced with "p" exiting on another core, resulting in no
                 * ref on "p".  Or, we may have failed to kill "p".
                 *
-                * Either way, we fall thru to here, leaving the proc in the 
+                * Either way, we fall thru to here, leaving the proc in the
                 * P_MEMSTAT_TERMINATED or P_MEMSTAT_ERROR state.
                 *
                 * And, we hold the the proc_list_lock at this point.
@@ -3495,274 +6114,433 @@ memorystatus_kill_top_process_aggressive(boolean_t any, uint32_t cause, int aggr
 
                next_p = memorystatus_get_first_proc_locked(&i, TRUE);
        }
-       
+
        proc_list_unlock();
-       
+
 exit:
+       os_reason_free(jetsam_reason);
+
        /* Clear snapshot if freshly captured and no target was found */
        if (new_snapshot && (kill_count == 0)) {
-           memorystatus_jetsam_snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
+               proc_list_lock();
+               memorystatus_jetsam_snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
+               proc_list_unlock();
        }
-       
+
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM) | DBG_FUNC_END,
-                             memorystatus_available_pages, killed ? aPid : 0, kill_count, 0, 0);
+           memorystatus_available_pages, killed ? aPid : 0, kill_count, 0, 0);
 
        if (kill_count > 0) {
-               return(TRUE);
-       }
-       else {
-               return(FALSE);
+               return TRUE;
+       } else {
+               return FALSE;
        }
 }
 
-#if LEGACY_HIWATER
-
 static boolean_t
-memorystatus_kill_hiwat_proc(uint32_t *errors)
+memorystatus_kill_hiwat_proc(uint32_t *errors, boolean_t *purged)
 {
        pid_t aPid = 0;
        proc_t p = PROC_NULL, next_p = PROC_NULL;
-       boolean_t new_snapshot = FALSE, killed = FALSE;
-       int kill_count = 0;
+       boolean_t new_snapshot = FALSE, killed = FALSE, freed_mem = FALSE;
        unsigned int i = 0;
        uint32_t aPid_ep;
-       
+       os_reason_t jetsam_reason = OS_REASON_NULL;
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM_HIWAT) | DBG_FUNC_START,
-               memorystatus_available_pages, 0, 0, 0, 0);
-       
+           memorystatus_available_pages, 0, 0, 0, 0);
+
+       jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_HIGHWATER);
+       if (jetsam_reason == OS_REASON_NULL) {
+               printf("memorystatus_kill_hiwat_proc: failed to allocate exit reason\n");
+       }
+
        proc_list_lock();
-       
+
        next_p = memorystatus_get_first_proc_locked(&i, TRUE);
        while (next_p) {
-               uint32_t footprint;
-               boolean_t skip;
+               uint64_t footprint_in_bytes = 0;
+               uint64_t memlimit_in_bytes  = 0;
+               boolean_t skip = 0;
 
                p = next_p;
                next_p = memorystatus_get_next_proc_locked(&i, p, TRUE);
-               
+
                aPid = p->p_pid;
                aPid_ep = p->p_memstat_effectivepriority;
-               
+
                if (p->p_memstat_state  & (P_MEMSTAT_ERROR | P_MEMSTAT_TERMINATED)) {
                        continue;
                }
-               
+
                /* skip if no limit set */
                if (p->p_memstat_memlimit <= 0) {
                        continue;
                }
 
-#if 0
-               /*
-                * No need to consider P_MEMSTAT_MEMLIMIT_BACKGROUND anymore.
-                * Background limits are described via the inactive limit slots.
-                * Their fatal/non-fatal setting will drive whether or not to be
-                * considered in this kill path.
-                */
+               footprint_in_bytes = get_task_phys_footprint(p->task);
+               memlimit_in_bytes  = (((uint64_t)p->p_memstat_memlimit) * 1024ULL * 1024ULL);   /* convert MB to bytes */
+               skip = (footprint_in_bytes <= memlimit_in_bytes);
 
-               /* skip if a currently inapplicable limit is encountered */
-               if ((p->p_memstat_state & P_MEMSTAT_MEMLIMIT_BACKGROUND) && (p->p_memstat_effectivepriority >= JETSAM_PRIORITY_FOREGROUND)) {          
-                       continue;
+#if CONFIG_JETSAM && (DEVELOPMENT || DEBUG)
+               if (!skip && (memorystatus_jetsam_policy & kPolicyDiagnoseActive)) {
+                       if (p->p_memstat_state & P_MEMSTAT_DIAG_SUSPENDED) {
+                               continue;
+                       }
+               }
+#endif /* CONFIG_JETSAM && (DEVELOPMENT || DEBUG) */
+
+#if CONFIG_FREEZE
+               if (!skip) {
+                       if (p->p_memstat_state & P_MEMSTAT_LOCKED) {
+                               skip = TRUE;
+                       } else {
+                               skip = FALSE;
+                       }
                }
 #endif
 
-               footprint = (uint32_t)(get_task_phys_footprint(p->task) / (1024 * 1024));
-               skip = (((int32_t)footprint) <= p->p_memstat_memlimit);
+               if (skip) {
+                       continue;
+               } else {
+                       if (memorystatus_jetsam_snapshot_count == 0) {
+                               memorystatus_init_jetsam_snapshot_locked(NULL, 0);
+                               new_snapshot = TRUE;
+                       }
 
-#if DEVELOPMENT || DEBUG
-               if (!skip && (memorystatus_jetsam_policy & kPolicyDiagnoseActive)) {
-                       if (p->p_memstat_state & P_MEMSTAT_DIAG_SUSPENDED) {
+                       if (proc_ref_locked(p) == p) {
+                               /*
+                                * Mark as terminated so that if exit1() indicates success, but the process (for example)
+                                * is blocked in task_exception_notify(), it'll be skipped if encountered again - see
+                                * <rdar://problem/13553476>. This is cheaper than examining P_LEXIT, which requires the
+                                * acquisition of the proc lock.
+                                */
+                               p->p_memstat_state |= P_MEMSTAT_TERMINATED;
+
+                               proc_list_unlock();
+                       } else {
+                               /*
+                                * We need to restart the search again because
+                                * proc_ref_locked _can_ drop the proc_list lock
+                                * and we could have lost our stored next_p via
+                                * an exit() on another core.
+                                */
+                               i = 0;
+                               next_p = memorystatus_get_first_proc_locked(&i, TRUE);
                                continue;
                        }
+
+                       freed_mem = memorystatus_kill_proc(p, kMemorystatusKilledHiwat, jetsam_reason, &killed); /* purged and/or killed 'p' */
+
+                       /* Success? */
+                       if (freed_mem) {
+                               if (killed == FALSE) {
+                                       /* purged 'p'..don't reset HWM candidate count */
+                                       *purged = TRUE;
+
+                                       proc_list_lock();
+                                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
+                                       proc_list_unlock();
+                               }
+                               proc_rele(p);
+                               goto exit;
+                       }
+                       /*
+                        * Failure - first unwind the state,
+                        * then fall through to restart the search.
+                        */
+                       proc_list_lock();
+                       proc_rele_locked(p);
+                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
+                       p->p_memstat_state |= P_MEMSTAT_ERROR;
+                       *errors += 1;
+
+                       i = 0;
+                       next_p = memorystatus_get_first_proc_locked(&i, TRUE);
+               }
+       }
+
+       proc_list_unlock();
+
+exit:
+       os_reason_free(jetsam_reason);
+
+       /* Clear snapshot if freshly captured and no target was found */
+       if (new_snapshot && !killed) {
+               proc_list_lock();
+               memorystatus_jetsam_snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
+               proc_list_unlock();
+       }
+
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM_HIWAT) | DBG_FUNC_END,
+           memorystatus_available_pages, killed ? aPid : 0, 0, 0, 0);
+
+       return killed;
+}
+
+/*
+ * Jetsam a process pinned in the elevated band.
+ *
+ * Return:  true -- at least one pinned process was jetsammed
+ *         false -- no pinned process was jetsammed
+ */
+static boolean_t
+memorystatus_kill_elevated_process(uint32_t cause, os_reason_t jetsam_reason, unsigned int band, int aggr_count, uint32_t *errors)
+{
+       pid_t aPid = 0;
+       proc_t p = PROC_NULL, next_p = PROC_NULL;
+       boolean_t new_snapshot = FALSE, killed = FALSE;
+       int kill_count = 0;
+       uint32_t aPid_ep;
+       uint64_t killtime = 0;
+       clock_sec_t     tv_sec;
+       clock_usec_t    tv_usec;
+       uint32_t        tv_msec;
+
+
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM) | DBG_FUNC_START,
+           memorystatus_available_pages, 0, 0, 0, 0);
+
+#if CONFIG_FREEZE
+       boolean_t consider_frozen_only = FALSE;
+
+       if (band == (unsigned int) memorystatus_freeze_jetsam_band) {
+               consider_frozen_only = TRUE;
+       }
+#endif /* CONFIG_FREEZE */
+
+       proc_list_lock();
+
+       next_p = memorystatus_get_first_proc_locked(&band, FALSE);
+       while (next_p) {
+               p = next_p;
+               next_p = memorystatus_get_next_proc_locked(&band, p, FALSE);
+
+               aPid = p->p_pid;
+               aPid_ep = p->p_memstat_effectivepriority;
+
+               /*
+                * Only pick a process pinned in this elevated band
+                */
+               if (!(p->p_memstat_state & P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND)) {
+                       continue;
+               }
+
+               if (p->p_memstat_state  & (P_MEMSTAT_ERROR | P_MEMSTAT_TERMINATED)) {
+                       continue;
                }
-#endif /* DEVELOPMENT || DEBUG */
 
 #if CONFIG_FREEZE
-               if (!skip) {
-                       if (p->p_memstat_state & P_MEMSTAT_LOCKED) {
-                               skip = TRUE;
-                       } else {
-                               skip = FALSE;
-                       }                               
+               if (consider_frozen_only && !(p->p_memstat_state & P_MEMSTAT_FROZEN)) {
+                       continue;
                }
-#endif
 
-               if (skip) {
+               if (p->p_memstat_state & P_MEMSTAT_LOCKED) {
                        continue;
-               } else {
-                       MEMORYSTATUS_DEBUG(1, "jetsam: %s pid %d [%s] - %d Mb > 1 (%d Mb)\n",
-                               (memorystatus_jetsam_policy & kPolicyDiagnoseActive) ? "suspending": "killing", aPid, p->p_comm, footprint, p->p_memstat_memlimit);
-                               
-                       if (memorystatus_jetsam_snapshot_count == 0) {
-                               memorystatus_init_jetsam_snapshot_locked(NULL,0);
-                               new_snapshot = TRUE;
-                       }
-                       
-                       p->p_memstat_state |= P_MEMSTAT_TERMINATED;
-                               
+               }
+#endif /* CONFIG_FREEZE */
+
 #if DEVELOPMENT || DEBUG
-                       if (memorystatus_jetsam_policy & kPolicyDiagnoseActive) {
-                               MEMORYSTATUS_DEBUG(1, "jetsam: pid %d suspended for diagnosis - memorystatus_available_pages: %d\n", aPid, memorystatus_available_pages);
-                               memorystatus_update_jetsam_snapshot_entry_locked(p, kMemorystatusKilledDiagnostic);
-                               p->p_memstat_state |= P_MEMSTAT_DIAG_SUSPENDED;
-                               
-                               p = proc_ref_locked(p);
-                               proc_list_unlock();
-                               if (p) {
-                                       task_suspend(p->task);
-                                       proc_rele(p);
-                                       killed = TRUE;
-                               }
-                               
-                               goto exit;
-                       } else
+               MEMORYSTATUS_DEBUG(1, "jetsam: elevated%d process pid %d [%s] - memorystatus_available_pages: %d\n",
+                   aggr_count,
+                   aPid, (*p->p_name ? p->p_name : "unknown"),
+                   memorystatus_available_pages);
 #endif /* DEVELOPMENT || DEBUG */
-                       {
-                               memorystatus_update_jetsam_snapshot_entry_locked(p, kMemorystatusKilledHiwat);
-                               
-                               if (proc_ref_locked(p) == p) {
-                                       proc_list_unlock();
 
-                                       printf("memorystatus: jetsam killing pid %d [%s] (highwater %d) - memorystatus_available_pages: %d\n", 
-                                              aPid, (p->p_comm ? p->p_comm : "(unknown)"), aPid_ep, memorystatus_available_pages);
+               if (memorystatus_jetsam_snapshot_count == 0) {
+                       memorystatus_init_jetsam_snapshot_locked(NULL, 0);
+                       new_snapshot = TRUE;
+               }
 
-                                       killed = memorystatus_do_kill(p, kMemorystatusKilledHiwat);
-                               
-                                       /* Success? */
-                                       if (killed) {
-                                               proc_rele(p);
-                                               kill_count++;
-                                               goto exit;
-                                       }
+               p->p_memstat_state |= P_MEMSTAT_TERMINATED;
 
-                                       /*
-                                        * Failure - first unwind the state,
-                                        * then fall through to restart the search.
-                                        */
-                                       proc_list_lock();
-                                       proc_rele_locked(p);
-                                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
-                                       p->p_memstat_state |= P_MEMSTAT_ERROR;
-                                       *errors += 1;
-                               }
+               killtime = mach_absolute_time();
+               absolutetime_to_microtime(killtime, &tv_sec, &tv_usec);
+               tv_msec = tv_usec / 1000;
 
-                               /*
-                                * Failure - restart the search.
-                                *
-                                * We might have raced with "p" exiting on another core, resulting in no
-                                * ref on "p".  Or, we may have failed to kill "p".
-                                *
-                                * Either way, we fall thru to here, leaving the proc in the 
-                                * P_MEMSTAT_TERMINATED state.
-                                *
-                                * And, we hold the the proc_list_lock at this point.
-                                */
+               memorystatus_update_jetsam_snapshot_entry_locked(p, cause, killtime);
 
-                               i = 0;
-                               next_p = memorystatus_get_first_proc_locked(&i, TRUE);
+               if (proc_ref_locked(p) == p) {
+                       proc_list_unlock();
+
+                       os_log_with_startup_serial(OS_LOG_DEFAULT, "%lu.%03d memorystatus: killing_top_process_elevated%d pid %d [%s] (%s %d) - memorystatus_available_pages: %llu\n",
+                           (unsigned long)tv_sec, tv_msec,
+                           aggr_count,
+                           aPid, (*p->p_name ? p->p_name : "unknown"),
+                           memorystatus_kill_cause_name[cause], aPid_ep, (uint64_t)memorystatus_available_pages);
+
+                       /*
+                        * memorystatus_do_kill drops a reference, so take another one so we can
+                        * continue to use this exit reason even after memorystatus_do_kill()
+                        * returns
+                        */
+                       os_reason_ref(jetsam_reason);
+                       killed = memorystatus_do_kill(p, cause, jetsam_reason);
+
+                       /* Success? */
+                       if (killed) {
+                               proc_rele(p);
+                               kill_count++;
+                               goto exit;
                        }
+
+                       /*
+                        * Failure - first unwind the state,
+                        * then fall through to restart the search.
+                        */
+                       proc_list_lock();
+                       proc_rele_locked(p);
+                       p->p_memstat_state &= ~P_MEMSTAT_TERMINATED;
+                       p->p_memstat_state |= P_MEMSTAT_ERROR;
+                       *errors += 1;
                }
+
+               /*
+                * Failure - restart the search.
+                *
+                * We might have raced with "p" exiting on another core, resulting in no
+                * ref on "p".  Or, we may have failed to kill "p".
+                *
+                * Either way, we fall thru to here, leaving the proc in the
+                * P_MEMSTAT_TERMINATED state or P_MEMSTAT_ERROR state.
+                *
+                * And, we hold the the proc_list_lock at this point.
+                */
+
+               next_p = memorystatus_get_first_proc_locked(&band, FALSE);
        }
-       
+
        proc_list_unlock();
-       
+
 exit:
+       os_reason_free(jetsam_reason);
+
        /* Clear snapshot if freshly captured and no target was found */
-       if (new_snapshot && !killed) {
+       if (new_snapshot && (kill_count == 0)) {
+               proc_list_lock();
                memorystatus_jetsam_snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
+               proc_list_unlock();
        }
-       
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM_HIWAT) | DBG_FUNC_END, 
-                             memorystatus_available_pages, killed ? aPid : 0, kill_count, 0, 0);
+
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_JETSAM) | DBG_FUNC_END,
+           memorystatus_available_pages, killed ? aPid : 0, kill_count, 0, 0);
 
        return killed;
 }
 
-#endif /* LEGACY_HIWATER */
-
-static boolean_t 
-memorystatus_kill_process_async(pid_t victim_pid, uint32_t cause) {
-       /* TODO: allow a general async path */
-       if ((victim_pid != -1) || (cause != kMemorystatusKilledVMPageShortage && cause != kMemorystatusKilledVMThrashing &&
-                                  cause != kMemorystatusKilledFCThrashing)) {
+static boolean_t
+memorystatus_kill_process_async(pid_t victim_pid, uint32_t cause)
+{
+       /*
+        * TODO: allow a general async path
+        *
+        * NOTE: If a new async kill cause is added, make sure to update memorystatus_thread() to
+        * add the appropriate exit reason code mapping.
+        */
+       if ((victim_pid != -1) ||
+           (cause != kMemorystatusKilledVMPageShortage &&
+           cause != kMemorystatusKilledVMCompressorThrashing &&
+           cause != kMemorystatusKilledVMCompressorSpaceShortage &&
+           cause != kMemorystatusKilledFCThrashing &&
+           cause != kMemorystatusKilledZoneMapExhaustion)) {
                return FALSE;
        }
-    
+
        kill_under_pressure_cause = cause;
        memorystatus_thread_wake();
        return TRUE;
 }
 
-static boolean_t 
-memorystatus_kill_process_sync(pid_t victim_pid, uint32_t cause) {
-       boolean_t res;
-       uint32_t errors = 0;
-    
-       if (victim_pid == -1) {
-               /* No pid, so kill first process */
-               res = memorystatus_kill_top_process(TRUE, TRUE, cause, NULL, &errors);
+boolean_t
+memorystatus_kill_on_VM_compressor_space_shortage(boolean_t async)
+{
+       if (async) {
+               return memorystatus_kill_process_async(-1, kMemorystatusKilledVMCompressorSpaceShortage);
        } else {
-               res = memorystatus_kill_specific_process(victim_pid, cause);
-       }
-       
-       if (errors) {
-               memorystatus_clear_errors();
-       }
-    
-       if (res == TRUE) {
-               /* Fire off snapshot notification */
-               size_t snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) + 
-                       sizeof(memorystatus_jetsam_snapshot_entry_t) * memorystatus_jetsam_snapshot_count;
-               uint64_t timestamp_now = mach_absolute_time();
-               memorystatus_jetsam_snapshot->notification_time = timestamp_now;
-               if (memorystatus_jetsam_snapshot_last_timestamp == 0 ||
-                               timestamp_now > memorystatus_jetsam_snapshot_last_timestamp + memorystatus_jetsam_snapshot_timeout) {
-                       int ret = memorystatus_send_note(kMemorystatusSnapshotNote, &snapshot_size, sizeof(snapshot_size));
-                       if (!ret) {
-                               proc_list_lock();
-                               memorystatus_jetsam_snapshot_last_timestamp = timestamp_now;
-                               proc_list_unlock();
-                       }
+               os_reason_t jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_VMCOMPRESSOR_SPACE_SHORTAGE);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_kill_on_VM_compressor_space_shortage -- sync: failed to allocate jetsam reason\n");
                }
+
+               return memorystatus_kill_process_sync(-1, kMemorystatusKilledVMCompressorSpaceShortage, jetsam_reason);
        }
-    
-       return res;
 }
 
-boolean_t 
-memorystatus_kill_on_VM_page_shortage(boolean_t async) {
+#if CONFIG_JETSAM
+boolean_t
+memorystatus_kill_on_VM_compressor_thrashing(boolean_t async)
+{
        if (async) {
-               return memorystatus_kill_process_async(-1, kMemorystatusKilledVMPageShortage);
+               return memorystatus_kill_process_async(-1, kMemorystatusKilledVMCompressorThrashing);
        } else {
-               return memorystatus_kill_process_sync(-1, kMemorystatusKilledVMPageShortage);
+               os_reason_t jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_VMCOMPRESSOR_THRASHING);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_kill_on_VM_compressor_thrashing -- sync: failed to allocate jetsam reason\n");
+               }
+
+               return memorystatus_kill_process_sync(-1, kMemorystatusKilledVMCompressorThrashing, jetsam_reason);
        }
 }
 
 boolean_t
-memorystatus_kill_on_VM_thrashing(boolean_t async) {
+memorystatus_kill_on_VM_page_shortage(boolean_t async)
+{
        if (async) {
-               return memorystatus_kill_process_async(-1, kMemorystatusKilledVMThrashing);
+               return memorystatus_kill_process_async(-1, kMemorystatusKilledVMPageShortage);
        } else {
-               return memorystatus_kill_process_sync(-1, kMemorystatusKilledVMThrashing);
+               os_reason_t jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_VMPAGESHORTAGE);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_kill_on_VM_page_shortage -- sync: failed to allocate jetsam reason\n");
+               }
+
+               return memorystatus_kill_process_sync(-1, kMemorystatusKilledVMPageShortage, jetsam_reason);
        }
 }
 
 boolean_t
-memorystatus_kill_on_FC_thrashing(boolean_t async) {
+memorystatus_kill_on_FC_thrashing(boolean_t async)
+{
        if (async) {
                return memorystatus_kill_process_async(-1, kMemorystatusKilledFCThrashing);
        } else {
-               return memorystatus_kill_process_sync(-1, kMemorystatusKilledFCThrashing);
+               os_reason_t jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_MEMORY_FCTHRASHING);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_kill_on_FC_thrashing -- sync: failed to allocate jetsam reason\n");
+               }
+
+               return memorystatus_kill_process_sync(-1, kMemorystatusKilledFCThrashing, jetsam_reason);
        }
 }
 
-boolean_t 
-memorystatus_kill_on_vnode_limit(void) {
-       return memorystatus_kill_process_sync(-1, kMemorystatusKilledVnodes);
+boolean_t
+memorystatus_kill_on_vnode_limit(void)
+{
+       os_reason_t jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_VNODE);
+       if (jetsam_reason == OS_REASON_NULL) {
+               printf("memorystatus_kill_on_vnode_limit: failed to allocate jetsam reason\n");
+       }
+
+       return memorystatus_kill_process_sync(-1, kMemorystatusKilledVnodes, jetsam_reason);
 }
 
 #endif /* CONFIG_JETSAM */
 
+boolean_t
+memorystatus_kill_on_zone_map_exhaustion(pid_t pid)
+{
+       boolean_t res = FALSE;
+       if (pid == -1) {
+               res = memorystatus_kill_process_async(-1, kMemorystatusKilledZoneMapExhaustion);
+       } else {
+               os_reason_t jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_ZONE_MAP_EXHAUSTION);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_kill_on_zone_map_exhaustion: failed to allocate jetsam reason\n");
+               }
+
+               res = memorystatus_kill_process_sync(pid, kMemorystatusKilledZoneMapExhaustion, jetsam_reason);
+       }
+       return res;
+}
+
 #if CONFIG_FREEZE
 
 __private_extern__ void
@@ -3775,18 +6553,86 @@ memorystatus_freeze_init(void)
        freezer_lck_grp = lck_grp_alloc_init("freezer", freezer_lck_grp_attr);
 
        lck_mtx_init(&freezer_mutex, freezer_lck_grp, NULL);
-               
+
+       /*
+        * This is just the default value if the underlying
+        * storage device doesn't have any specific budget.
+        * We check with the storage layer in memorystatus_freeze_update_throttle()
+        * before we start our freezing the first time.
+        */
+       memorystatus_freeze_budget_pages_remaining = (memorystatus_freeze_daily_mb_max * 1024 * 1024) / PAGE_SIZE;
+
        result = kernel_thread_start(memorystatus_freeze_thread, NULL, &thread);
        if (result == KERN_SUCCESS) {
+               proc_set_thread_policy(thread, TASK_POLICY_INTERNAL, TASK_POLICY_IO, THROTTLE_LEVEL_COMPRESSOR_TIER2);
+               proc_set_thread_policy(thread, TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+               thread_set_thread_name(thread, "VM_freezer");
+
                thread_deallocate(thread);
        } else {
                panic("Could not create memorystatus_freeze_thread");
        }
 }
 
+static boolean_t
+memorystatus_is_process_eligible_for_freeze(proc_t p)
+{
+       /*
+        * Called with proc_list_lock held.
+        */
+
+       LCK_MTX_ASSERT(proc_list_mlock, LCK_MTX_ASSERT_OWNED);
+
+       boolean_t should_freeze = FALSE;
+       uint32_t state = 0, entry_count = 0, pages = 0, i = 0;
+       int probability_of_use = 0;
+
+       if (isApp(p) == FALSE) {
+               goto out;
+       }
+
+       state = p->p_memstat_state;
+
+       if ((state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_FREEZE_DISABLED | P_MEMSTAT_FREEZE_IGNORE)) ||
+           !(state & P_MEMSTAT_SUSPENDED)) {
+               goto out;
+       }
+
+       /* Only freeze processes meeting our minimum resident page criteria */
+       memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL);
+       if (pages < memorystatus_freeze_pages_min) {
+               goto out;
+       }
+
+       entry_count = (memorystatus_global_probabilities_size / sizeof(memorystatus_internal_probabilities_t));
+
+       if (entry_count) {
+               for (i = 0; i < entry_count; i++) {
+                       if (strncmp(memorystatus_global_probabilities_table[i].proc_name,
+                           p->p_name,
+                           MAXCOMLEN + 1) == 0) {
+                               probability_of_use = memorystatus_global_probabilities_table[i].use_probability;
+                               break;
+                       }
+               }
+
+               if (probability_of_use == 0) {
+                       goto out;
+               }
+       }
+
+       should_freeze = TRUE;
+out:
+       return should_freeze;
+}
+
 /*
  * Synchronously freeze the passed proc. Called with a reference to the proc held.
  *
+ * Doesn't deal with re-freezing because this is called on a specific process and
+ * not by the freezer thread. If that changes, we'll have to teach it about
+ * refreezing a frozen process.
+ *
  * Returns EINVAL or the value returned by task_freeze().
  */
 int
@@ -3795,76 +6641,47 @@ memorystatus_freeze_process_sync(proc_t p)
        int ret = EINVAL;
        pid_t aPid = 0;
        boolean_t memorystatus_freeze_swap_low = FALSE;
-
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_START,
-               memorystatus_available_pages, 0, 0, 0, 0);
+       int     freezer_error_code = 0;
 
        lck_mtx_lock(&freezer_mutex);
 
        if (p == NULL) {
+               printf("memorystatus_freeze_process_sync: Invalid process\n");
                goto exit;
        }
 
        if (memorystatus_freeze_enabled == FALSE) {
+               printf("memorystatus_freeze_process_sync: Freezing is DISABLED\n");
                goto exit;
        }
 
        if (!memorystatus_can_freeze(&memorystatus_freeze_swap_low)) {
+               printf("memorystatus_freeze_process_sync: Low compressor and/or low swap space...skipping freeze\n");
                goto exit;
        }
 
-       if (memorystatus_freeze_update_throttle()) {
-               printf("memorystatus_freeze_process_sync: in throttle, ignorning freeze\n");
-               memorystatus_freeze_throttle_count++;
+       memorystatus_freeze_update_throttle(&memorystatus_freeze_budget_pages_remaining);
+       if (!memorystatus_freeze_budget_pages_remaining) {
+               printf("memorystatus_freeze_process_sync: exit with NO available budget\n");
                goto exit;
        }
 
        proc_list_lock();
 
        if (p != NULL) {
-               uint32_t purgeable, wired, clean, dirty, state;
-               uint32_t max_pages, pages, i;
-               boolean_t shared;
+               uint32_t purgeable, wired, clean, dirty, shared;
+               uint32_t max_pages, i;
 
                aPid = p->p_pid;
-               state = p->p_memstat_state;
 
                /* Ensure the process is eligible for freezing */
-               if ((state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_FROZEN)) || !(state & P_MEMSTAT_SUSPENDED)) {
-                       proc_list_unlock();
-                       goto exit;
-               }
-
-               /* Only freeze processes meeting our minimum resident page criteria */
-               memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL, NULL);
-               if (pages < memorystatus_freeze_pages_min) {
+               if (memorystatus_is_process_eligible_for_freeze(p) == FALSE) {
                        proc_list_unlock();
                        goto exit;
                }
 
-               if (DEFAULT_FREEZER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPBACKED) {
-
-                       unsigned int avail_swap_space = 0; /* in pages. */
-
-                       if (DEFAULT_FREEZER_IS_ACTIVE) {
-                               /*
-                                * Freezer backed by default pager and swap file(s).
-                                */
-                               avail_swap_space = default_pager_swap_pages_free();
-                       } else {
-                               /*
-                                * Freezer backed by the compressor and swap file(s)
-                                * while will hold compressed data.
-                                */
-                               avail_swap_space = vm_swap_get_free_space() / PAGE_SIZE_64;
-                       }
-
-                       max_pages = MIN(avail_swap_space, memorystatus_freeze_pages_max);
-
-                       if (max_pages < memorystatus_freeze_pages_min) {
-                               proc_list_unlock();
-                               goto exit;
-                       }
+               if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                       max_pages = MIN(memorystatus_freeze_pages_max, memorystatus_freeze_budget_pages_remaining);
                } else {
                        /*
                         * We only have the compressor without any swap.
@@ -3876,207 +6693,389 @@ memorystatus_freeze_process_sync(proc_t p)
                p->p_memstat_state |= P_MEMSTAT_LOCKED;
                proc_list_unlock();
 
-               ret = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, FALSE);
+               KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_START,
+                   memorystatus_available_pages, 0, 0, 0, 0);
+
+               ret = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, &freezer_error_code, FALSE /* eval only */);
+
+               KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_END,
+                   memorystatus_available_pages, aPid, 0, 0, 0);
+
+               DTRACE_MEMORYSTATUS6(memorystatus_freeze, proc_t, p, unsigned int, memorystatus_available_pages, boolean_t, purgeable, unsigned int, wired, uint32_t, clean, uint32_t, dirty);
 
                MEMORYSTATUS_DEBUG(1, "memorystatus_freeze_process_sync: task_freeze %s for pid %d [%s] - "
-                       "memorystatus_pages: %d, purgeable: %d, wired: %d, clean: %d, dirty: %d, shared %d, free swap: %d\n",
-                       (ret == KERN_SUCCESS) ? "SUCCEEDED" : "FAILED", aPid, (p->p_comm ? p->p_comm : "(unknown)"),
-                       memorystatus_available_pages, purgeable, wired, clean, dirty, shared, default_pager_swap_pages_free());
+                   "memorystatus_pages: %d, purgeable: %d, wired: %d, clean: %d, dirty: %d, max_pages %d, shared %d\n",
+                   (ret == KERN_SUCCESS) ? "SUCCEEDED" : "FAILED", aPid, (*p->p_name ? p->p_name : "(unknown)"),
+                   memorystatus_available_pages, purgeable, wired, clean, dirty, max_pages, shared);
 
                proc_list_lock();
-               p->p_memstat_state &= ~P_MEMSTAT_LOCKED;
 
                if (ret == KERN_SUCCESS) {
+                       os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: freezing (specific) pid %d [%s]...done",
+                           aPid, (*p->p_name ? p->p_name : "unknown"));
+
                        memorystatus_freeze_entry_t data = { aPid, TRUE, dirty };
 
-                       memorystatus_frozen_count++;
+                       p->p_memstat_freeze_sharedanon_pages += shared;
+
+                       memorystatus_frozen_shared_mb += shared;
+
+                       if ((p->p_memstat_state & P_MEMSTAT_FROZEN) == 0) {
+                               p->p_memstat_state |= P_MEMSTAT_FROZEN;
+                               memorystatus_frozen_count++;
+                       }
+
+                       p->p_memstat_frozen_count++;
+
+                       /*
+                        * Still keeping the P_MEMSTAT_LOCKED bit till we are actually done elevating this frozen process
+                        * to its higher jetsam band.
+                        */
+                       proc_list_unlock();
+
+                       memorystatus_send_note(kMemorystatusFreezeNote, &data, sizeof(data));
+
+                       if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                               ret = memorystatus_update_inactive_jetsam_priority_band(p->p_pid, MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_ENABLE,
+                                   memorystatus_freeze_jetsam_band, TRUE);
+
+                               if (ret) {
+                                       printf("Elevating the frozen process failed with %d\n", ret);
+                                       /* not fatal */
+                                       ret = 0;
+                               }
 
-                       p->p_memstat_state |= (P_MEMSTAT_FROZEN | (shared ? 0: P_MEMSTAT_NORECLAIM));
+                               proc_list_lock();
 
-                       if (DEFAULT_FREEZER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPBACKED) {
                                /* Update stats */
                                for (i = 0; i < sizeof(throttle_intervals) / sizeof(struct throttle_interval_t); i++) {
                                        throttle_intervals[i].pageouts += dirty;
                                }
+                       } else {
+                               proc_list_lock();
                        }
 
                        memorystatus_freeze_pageouts += dirty;
-                       memorystatus_freeze_count++;
 
-                       proc_list_unlock();
-
-                       memorystatus_send_note(kMemorystatusFreezeNote, &data, sizeof(data));
+                       if (memorystatus_frozen_count == (memorystatus_frozen_processes_max - 1)) {
+                               /*
+                                * Add some eviction logic here? At some point should we
+                                * jetsam a process to get back its swap space so that we
+                                * can freeze a more eligible process at this moment in time?
+                                */
+                       }
                } else {
-                       proc_list_unlock();
+                       char reason[128];
+                       if (freezer_error_code == FREEZER_ERROR_EXCESS_SHARED_MEMORY) {
+                               strlcpy(reason, "too much shared memory", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_LOW_PRIVATE_SHARED_RATIO) {
+                               strlcpy(reason, "low private-shared pages ratio", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_NO_COMPRESSOR_SPACE) {
+                               strlcpy(reason, "no compressor space", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_NO_SWAP_SPACE) {
+                               strlcpy(reason, "no swap space", 128);
+                       }
+
+                       os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: freezing (specific) pid %d [%s]...skipped (%s)",
+                           aPid, (*p->p_name ? p->p_name : "unknown"), reason);
+                       p->p_memstat_state |= P_MEMSTAT_FREEZE_IGNORE;
                }
+
+               p->p_memstat_state &= ~P_MEMSTAT_LOCKED;
+               proc_list_unlock();
        }
 
 exit:
        lck_mtx_unlock(&freezer_mutex);
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_END,
-               memorystatus_available_pages, aPid, 0, 0, 0);
 
        return ret;
 }
 
 static int
-memorystatus_freeze_top_process(boolean_t *memorystatus_freeze_swap_low)
+memorystatus_freeze_top_process(void)
 {
        pid_t aPid = 0;
        int ret = -1;
        proc_t p = PROC_NULL, next_p = PROC_NULL;
        unsigned int i = 0;
-
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_START,
-               memorystatus_available_pages, 0, 0, 0, 0);
+       unsigned int band = JETSAM_PRIORITY_IDLE;
+       boolean_t refreeze_processes = FALSE;
 
        proc_list_lock();
-       
-       next_p = memorystatus_get_first_proc_locked(&i, TRUE);
+
+       if (memorystatus_frozen_count >= memorystatus_frozen_processes_max) {
+               /*
+                * Freezer is already full but we are here and so let's
+                * try to refreeze any processes we might have thawed
+                * in the past and push out their compressed state out.
+                */
+               refreeze_processes = TRUE;
+               band = (unsigned int) memorystatus_freeze_jetsam_band;
+       }
+
+freeze_process:
+
+       next_p = memorystatus_get_first_proc_locked(&band, FALSE);
        while (next_p) {
                kern_return_t kr;
-               uint32_t purgeable, wired, clean, dirty;
-               boolean_t shared;
-               uint32_t pages;
+               uint32_t purgeable, wired, clean, dirty, shared;
                uint32_t max_pages = 0;
-               uint32_t state;
-               
+               int     freezer_error_code = 0;
+
                p = next_p;
-               next_p = memorystatus_get_next_proc_locked(&i, p, TRUE);
+               next_p = memorystatus_get_next_proc_locked(&band, p, FALSE);
 
                aPid = p->p_pid;
-               state = p->p_memstat_state;
 
-               /* Ensure the process is eligible for freezing */
-               if ((state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_FROZEN)) || !(state & P_MEMSTAT_SUSPENDED)) {
-                       continue; // with lock held
+               if (p->p_memstat_effectivepriority != (int32_t) band) {
+                       /*
+                        * We shouldn't be freezing processes outside the
+                        * prescribed band.
+                        */
+                       break;
                }
-                                       
-               /* Only freeze processes meeting our minimum resident page criteria */
-               memorystatus_get_task_page_counts(p->task, &pages, NULL, NULL, NULL);
-               if (pages < memorystatus_freeze_pages_min) {
-                       continue; // with lock held
-               } 
 
-               if (DEFAULT_FREEZER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPBACKED) {
+               /* Ensure the process is eligible for (re-)freezing */
+               if (refreeze_processes) {
+                       /*
+                        * Has to have been frozen once before.
+                        */
+                       if ((p->p_memstat_state & P_MEMSTAT_FROZEN) == FALSE) {
+                               continue;
+                       }
+
+                       /*
+                        * Has to have been resumed once before.
+                        */
+                       if ((p->p_memstat_state & P_MEMSTAT_REFREEZE_ELIGIBLE) == FALSE) {
+                               continue;
+                       }
 
-                       /* Ensure there's enough free space to freeze this process. */
+                       /*
+                        * Not currently being looked at for something.
+                        */
+                       if (p->p_memstat_state & P_MEMSTAT_LOCKED) {
+                               continue;
+                       }
 
-                       unsigned int avail_swap_space = 0; /* in pages. */
+                       /*
+                        * We are going to try and refreeze and so re-evaluate
+                        * the process. We don't want to double count the shared
+                        * memory. So deduct the old snapshot here.
+                        */
+                       memorystatus_frozen_shared_mb -= p->p_memstat_freeze_sharedanon_pages;
+                       p->p_memstat_freeze_sharedanon_pages = 0;
 
-                       if (DEFAULT_FREEZER_IS_ACTIVE) {
-                               /*
-                                * Freezer backed by default pager and swap file(s).
-                                */
-                               avail_swap_space = default_pager_swap_pages_free();
-                       } else {
-                               /*
-                                * Freezer backed by the compressor and swap file(s)
-                                * while will hold compressed data.
-                                */
-                               avail_swap_space = vm_swap_get_free_space() / PAGE_SIZE_64;
+                       p->p_memstat_state &= ~P_MEMSTAT_REFREEZE_ELIGIBLE;
+                       memorystatus_refreeze_eligible_count--;
+               } else {
+                       if (memorystatus_is_process_eligible_for_freeze(p) == FALSE) {
+                               continue; // with lock held
                        }
+               }
 
-                       max_pages = MIN(avail_swap_space, memorystatus_freeze_pages_max);
+               if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                       /*
+                        * Freezer backed by the compressor and swap file(s)
+                        * will hold compressed data.
+                        */
 
-                       if (max_pages < memorystatus_freeze_pages_min) {
-                               *memorystatus_freeze_swap_low = TRUE;
-                               proc_list_unlock();
-                               goto exit;
-                       }
+                       max_pages = MIN(memorystatus_freeze_pages_max, memorystatus_freeze_budget_pages_remaining);
                } else {
                        /*
                         * We only have the compressor pool.
                         */
                        max_pages = UINT32_MAX - 1;
                }
-               
+
                /* Mark as locked temporarily to avoid kill */
                p->p_memstat_state |= P_MEMSTAT_LOCKED;
 
                p = proc_ref_locked(p);
-               proc_list_unlock();        
                if (!p) {
-                       goto exit;
+                       break;
                }
-        
-               kr = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, FALSE);
-               
+
+               proc_list_unlock();
+
+               KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_START,
+                   memorystatus_available_pages, 0, 0, 0, 0);
+
+               kr = task_freeze(p->task, &purgeable, &wired, &clean, &dirty, max_pages, &shared, &freezer_error_code, FALSE /* eval only */);
+
+               KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_END,
+                   memorystatus_available_pages, aPid, 0, 0, 0);
+
                MEMORYSTATUS_DEBUG(1, "memorystatus_freeze_top_process: task_freeze %s for pid %d [%s] - "
-                       "memorystatus_pages: %d, purgeable: %d, wired: %d, clean: %d, dirty: %d, shared %d, free swap: %d\n", 
-                       (kr == KERN_SUCCESS) ? "SUCCEEDED" : "FAILED", aPid, (p->p_comm ? p->p_comm : "(unknown)"), 
-                       memorystatus_available_pages, purgeable, wired, clean, dirty, shared, default_pager_swap_pages_free());
-     
+                   "memorystatus_pages: %d, purgeable: %d, wired: %d, clean: %d, dirty: %d, max_pages %d, shared %d\n",
+                   (kr == KERN_SUCCESS) ? "SUCCEEDED" : "FAILED", aPid, (*p->p_name ? p->p_name : "(unknown)"),
+                   memorystatus_available_pages, purgeable, wired, clean, dirty, max_pages, shared);
+
                proc_list_lock();
-               p->p_memstat_state &= ~P_MEMSTAT_LOCKED;
-               
+
                /* Success? */
                if (KERN_SUCCESS == kr) {
+                       if (refreeze_processes) {
+                               os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: Refreezing (general) pid %d [%s]...done",
+                                   aPid, (*p->p_name ? p->p_name : "unknown"));
+                       } else {
+                               os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: freezing (general) pid %d [%s]...done",
+                                   aPid, (*p->p_name ? p->p_name : "unknown"));
+                       }
+
                        memorystatus_freeze_entry_t data = { aPid, TRUE, dirty };
-                       
-                       memorystatus_frozen_count++;
-                       
-                       p->p_memstat_state |= (P_MEMSTAT_FROZEN | (shared ? 0: P_MEMSTAT_NORECLAIM));
-               
-                       if (DEFAULT_FREEZER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPBACKED) {
+
+                       p->p_memstat_freeze_sharedanon_pages += shared;
+
+                       memorystatus_frozen_shared_mb += shared;
+
+                       if ((p->p_memstat_state & P_MEMSTAT_FROZEN) == 0) {
+                               p->p_memstat_state |= P_MEMSTAT_FROZEN;
+                               memorystatus_frozen_count++;
+                       }
+
+                       p->p_memstat_frozen_count++;
+
+                       /*
+                        * Still keeping the P_MEMSTAT_LOCKED bit till we are actually done elevating this frozen process
+                        * to its higher jetsam band.
+                        */
+                       proc_list_unlock();
+
+                       memorystatus_send_note(kMemorystatusFreezeNote, &data, sizeof(data));
+
+                       if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+                               ret = memorystatus_update_inactive_jetsam_priority_band(p->p_pid, MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_ENABLE, memorystatus_freeze_jetsam_band, TRUE);
+
+                               if (ret) {
+                                       printf("Elevating the frozen process failed with %d\n", ret);
+                                       /* not fatal */
+                                       ret = 0;
+                               }
+
+                               proc_list_lock();
+
                                /* Update stats */
                                for (i = 0; i < sizeof(throttle_intervals) / sizeof(struct throttle_interval_t); i++) {
                                        throttle_intervals[i].pageouts += dirty;
                                }
+                       } else {
+                               proc_list_lock();
                        }
 
                        memorystatus_freeze_pageouts += dirty;
-                       memorystatus_freeze_count++;
-
-                       proc_list_unlock();
 
-                       memorystatus_send_note(kMemorystatusFreezeNote, &data, sizeof(data));
+                       if (memorystatus_frozen_count == (memorystatus_frozen_processes_max - 1)) {
+                               /*
+                                * Add some eviction logic here? At some point should we
+                                * jetsam a process to get back its swap space so that we
+                                * can freeze a more eligible process at this moment in time?
+                                */
+                       }
 
-                       /* Return KERN_SUCESS */
+                       /* Return KERN_SUCCESS */
                        ret = kr;
 
+                       p->p_memstat_state &= ~P_MEMSTAT_LOCKED;
+                       proc_rele_locked(p);
+
+                       /*
+                        * We froze a process successfully. We can stop now
+                        * and see if that helped.
+                        */
+
+                       break;
                } else {
-                       proc_list_unlock();
+                       p->p_memstat_state &= ~P_MEMSTAT_LOCKED;
+
+                       if (refreeze_processes == TRUE) {
+                               if ((freezer_error_code == FREEZER_ERROR_EXCESS_SHARED_MEMORY) ||
+                                   (freezer_error_code == FREEZER_ERROR_LOW_PRIVATE_SHARED_RATIO)) {
+                                       /*
+                                        * Keeping this prior-frozen process in this high band when
+                                        * we failed to re-freeze it due to bad shared memory usage
+                                        * could cause excessive pressure on the lower bands.
+                                        * We need to demote it for now. It'll get re-evaluated next
+                                        * time because we don't set the P_MEMSTAT_FREEZE_IGNORE
+                                        * bit.
+                                        */
+
+                                       p->p_memstat_state &= ~P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND;
+                                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+                                       memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, TRUE, TRUE);
+                               }
+                       } else {
+                               p->p_memstat_state |= P_MEMSTAT_FREEZE_IGNORE;
+                       }
+
+                       proc_rele_locked(p);
+
+                       char reason[128];
+                       if (freezer_error_code == FREEZER_ERROR_EXCESS_SHARED_MEMORY) {
+                               strlcpy(reason, "too much shared memory", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_LOW_PRIVATE_SHARED_RATIO) {
+                               strlcpy(reason, "low private-shared pages ratio", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_NO_COMPRESSOR_SPACE) {
+                               strlcpy(reason, "no compressor space", 128);
+                       }
+
+                       if (freezer_error_code == FREEZER_ERROR_NO_SWAP_SPACE) {
+                               strlcpy(reason, "no swap space", 128);
+                       }
+
+                       os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: freezing (general) pid %d [%s]...skipped (%s)",
+                           aPid, (*p->p_name ? p->p_name : "unknown"), reason);
+
+                       if (vm_compressor_low_on_space() || vm_swap_low_on_space()) {
+                               break;
+                       }
                }
-        
-               proc_rele(p);
-               goto exit;
        }
-       
+
+       if ((ret == -1) &&
+           (memorystatus_refreeze_eligible_count >= MIN_THAW_REFREEZE_THRESHOLD) &&
+           (refreeze_processes == FALSE)) {
+               /*
+                * We failed to freeze a process from the IDLE
+                * band AND we have some thawed  processes
+                * AND haven't tried refreezing as yet.
+                * Let's try and re-freeze processes in the
+                * frozen band that have been resumed in the past
+                * and so have brought in state from disk.
+                */
+
+               band = (unsigned int) memorystatus_freeze_jetsam_band;
+
+               refreeze_processes = TRUE;
+
+               goto freeze_process;
+       }
+
        proc_list_unlock();
-       
-exit:
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_FREEZE) | DBG_FUNC_END,
-               memorystatus_available_pages, aPid, 0, 0, 0);
-       
+
        return ret;
 }
 
-static inline boolean_t 
-memorystatus_can_freeze_processes(void) 
+static inline boolean_t
+memorystatus_can_freeze_processes(void)
 {
        boolean_t ret;
-       
+
        proc_list_lock();
-       
+
        if (memorystatus_suspended_count) {
-               uint32_t average_resident_pages, estimated_processes;
-        
-               /* Estimate the number of suspended processes we can fit */
-               average_resident_pages = memorystatus_suspended_footprint_total / memorystatus_suspended_count;
-               estimated_processes = memorystatus_suspended_count +
-                       ((memorystatus_available_pages - memorystatus_available_pages_critical) / average_resident_pages);
-
-               /* If it's predicted that no freeze will occur, lower the threshold temporarily */
-               if (estimated_processes <= FREEZE_SUSPENDED_THRESHOLD_DEFAULT) {
-                       memorystatus_freeze_suspended_threshold = FREEZE_SUSPENDED_THRESHOLD_LOW;
-               } else {
-                       memorystatus_freeze_suspended_threshold = FREEZE_SUSPENDED_THRESHOLD_DEFAULT;
-               }
+               memorystatus_freeze_suspended_threshold = MIN(memorystatus_freeze_suspended_threshold, FREEZE_SUSPENDED_THRESHOLD_DEFAULT);
 
-               MEMORYSTATUS_DEBUG(1, "memorystatus_can_freeze_processes: %d suspended processes, %d average resident pages / process, %d suspended processes estimated\n", 
-                       memorystatus_suspended_count, average_resident_pages, estimated_processes);
-       
                if ((memorystatus_suspended_count - memorystatus_frozen_count) > memorystatus_freeze_suspended_threshold) {
                        ret = TRUE;
                } else {
@@ -4085,40 +7084,39 @@ memorystatus_can_freeze_processes(void)
        } else {
                ret = FALSE;
        }
-                               
+
        proc_list_unlock();
-       
+
        return ret;
 }
 
-static boolean_t 
+static boolean_t
 memorystatus_can_freeze(boolean_t *memorystatus_freeze_swap_low)
 {
        boolean_t can_freeze = TRUE;
 
        /* Only freeze if we're sufficiently low on memory; this holds off freeze right
-          after boot,  and is generally is a no-op once we've reached steady state. */
+       *  after boot,  and is generally is a no-op once we've reached steady state. */
        if (memorystatus_available_pages > memorystatus_freeze_threshold) {
                return FALSE;
        }
-       
+
        /* Check minimum suspended process threshold. */
        if (!memorystatus_can_freeze_processes()) {
                return FALSE;
        }
+       assert(VM_CONFIG_COMPRESSOR_IS_PRESENT);
 
-       if (COMPRESSED_PAGER_IS_SWAPLESS || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPLESS) {
+       if (!VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
                /*
                 * In-core compressor used for freezing WITHOUT on-disk swap support.
                 */
-
                if (vm_compressor_low_on_space()) {
                        if (*memorystatus_freeze_swap_low) {
                                *memorystatus_freeze_swap_low = TRUE;
                        }
 
                        can_freeze = FALSE;
-
                } else {
                        if (*memorystatus_freeze_swap_low) {
                                *memorystatus_freeze_swap_low = FALSE;
@@ -4129,125 +7127,357 @@ memorystatus_can_freeze(boolean_t *memorystatus_freeze_swap_low)
        } else {
                /*
                 * Freezing WITH on-disk swap support.
+                *
+                * In-core compressor fronts the swap.
                 */
+               if (vm_swap_low_on_space()) {
+                       if (*memorystatus_freeze_swap_low) {
+                               *memorystatus_freeze_swap_low = TRUE;
+                       }
 
-               if (DEFAULT_FREEZER_COMPRESSED_PAGER_IS_SWAPBACKED) {
-                       /*
-                        * In-core compressor fronts the swap.
-                        */
-                       if (vm_swap_low_on_space()) {
-                               if (*memorystatus_freeze_swap_low) {
-                                       *memorystatus_freeze_swap_low = TRUE;
-                               }
+                       can_freeze = FALSE;
+               }
+       }
 
-                               can_freeze = FALSE;
-                       }
+       return can_freeze;
+}
+
+/*
+ * This function evaluates if the currently frozen processes deserve
+ * to stay in the higher jetsam band. If the # of thaws of a process
+ * is below our threshold, then we will demote that process into the IDLE
+ * band and put it at the head. We don't immediately kill the process here
+ * because it  already has state on disk and so it might be worth giving
+ * it another shot at getting thawed/resumed and used.
+ */
+static void
+memorystatus_demote_frozen_processes(void)
+{
+       unsigned int band = (unsigned int) memorystatus_freeze_jetsam_band;
+       unsigned int demoted_proc_count = 0;
+       proc_t p = PROC_NULL, next_p = PROC_NULL;
+
+       proc_list_lock();
+
+       if (memorystatus_freeze_enabled == FALSE) {
+               /*
+                * Freeze has been disabled likely to
+                * reclaim swap space. So don't change
+                * any state on the frozen processes.
+                */
+               proc_list_unlock();
+               return;
+       }
+
+       next_p = memorystatus_get_first_proc_locked(&band, FALSE);
+       while (next_p) {
+               p = next_p;
+               next_p = memorystatus_get_next_proc_locked(&band, p, FALSE);
+
+               if ((p->p_memstat_state & P_MEMSTAT_FROZEN) == FALSE) {
+                       continue;
+               }
+
+               if (p->p_memstat_state & P_MEMSTAT_LOCKED) {
+                       continue;
+               }
+
+               if (p->p_memstat_thaw_count < memorystatus_thaw_count_demotion_threshold) {
+                       p->p_memstat_state &= ~P_MEMSTAT_USE_ELEVATED_INACTIVE_BAND;
+                       memorystatus_invalidate_idle_demotion_locked(p, TRUE);
+
+                       memorystatus_update_priority_locked(p, JETSAM_PRIORITY_IDLE, TRUE, TRUE);
+#if DEVELOPMENT || DEBUG
+                       os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus_demote_frozen_process pid %d [%s]",
+                           p->p_pid, (*p->p_name ? p->p_name : "unknown"));
+#endif /* DEVELOPMENT || DEBUG */
 
-               } else if (DEFAULT_FREEZER_IS_ACTIVE) {
                        /*
-                        * Legacy freeze mode with no compressor support.
+                        * The freezer thread will consider this a normal app to be frozen
+                        * because it is in the IDLE band. So we don't need the
+                        * P_MEMSTAT_REFREEZE_ELIGIBLE state here. Also, if it gets resumed
+                        * we'll correctly count it as eligible for re-freeze again.
+                        *
+                        * We don't drop the frozen count because this process still has
+                        * state on disk. So there's a chance it gets resumed and then it
+                        * should land in the higher jetsam band. For that it needs to
+                        * remain marked frozen.
                         */
-                       if (default_pager_swap_pages_free() < memorystatus_freeze_pages_min) {
-                               if (*memorystatus_freeze_swap_low) {
-                                       *memorystatus_freeze_swap_low = TRUE;
-                               }
-
-                               can_freeze = FALSE;
+                       if (p->p_memstat_state & P_MEMSTAT_REFREEZE_ELIGIBLE) {
+                               p->p_memstat_state &= ~P_MEMSTAT_REFREEZE_ELIGIBLE;
+                               memorystatus_refreeze_eligible_count--;
                        }
-               } else {
-                       panic("Not a valid freeze configuration.\n");
+
+                       demoted_proc_count++;
+               }
+
+               if (demoted_proc_count == memorystatus_max_frozen_demotions_daily) {
+                       break;
                }
        }
-       
-       return can_freeze;
+
+       memorystatus_thaw_count = 0;
+       proc_list_unlock();
 }
 
+
+/*
+ * This function will do 4 things:
+ *
+ * 1) check to see if we are currently in a degraded freezer mode, and if so:
+ *     - check to see if our window has expired and we should exit this mode, OR,
+ *     - return a budget based on the degraded throttle window's max. pageouts vs current pageouts.
+ *
+ * 2) check to see if we are in a NEW normal window and update the normal throttle window's params.
+ *
+ * 3) check what the current normal window allows for a budget.
+ *
+ * 4) calculate the current rate of pageouts for DEGRADED_WINDOW_MINS duration. If that rate is below
+ *    what we would normally expect, then we are running low on our daily budget and need to enter
+ *    degraded perf. mode.
+ */
+
 static void
-memorystatus_freeze_update_throttle_interval(mach_timespec_t *ts, struct throttle_interval_t *interval)
+memorystatus_freeze_update_throttle(uint64_t *budget_pages_allowed)
 {
-       unsigned int freeze_daily_pageouts_max = memorystatus_freeze_daily_mb_max * (1024 * 1024 / PAGE_SIZE);
-       if (CMP_MACH_TIMESPEC(ts, &interval->ts) >= 0) {
-               if (!interval->max_pageouts) {
-                       interval->max_pageouts = (interval->burst_multiple * (((uint64_t)interval->mins * freeze_daily_pageouts_max) / (24 * 60)));
+       clock_sec_t sec;
+       clock_nsec_t nsec;
+       mach_timespec_t ts;
+
+       unsigned int freeze_daily_pageouts_max = 0;
+
+#if DEVELOPMENT || DEBUG
+       if (!memorystatus_freeze_throttle_enabled) {
+               /*
+                * No throttling...we can use the full budget everytime.
+                */
+               *budget_pages_allowed = UINT64_MAX;
+               return;
+       }
+#endif
+
+       clock_get_system_nanotime(&sec, &nsec);
+       ts.tv_sec = sec;
+       ts.tv_nsec = nsec;
+
+       struct throttle_interval_t *interval = NULL;
+
+       if (memorystatus_freeze_degradation == TRUE) {
+               interval = degraded_throttle_window;
+
+               if (CMP_MACH_TIMESPEC(&ts, &interval->ts) >= 0) {
+                       memorystatus_freeze_degradation = FALSE;
+                       interval->pageouts = 0;
+                       interval->max_pageouts = 0;
                } else {
-                       printf("memorystatus_freeze_update_throttle_interval: %d minute throttle timeout, resetting\n", interval->mins);
+                       *budget_pages_allowed = interval->max_pageouts - interval->pageouts;
+               }
+       }
+
+       interval = normal_throttle_window;
+
+       if (CMP_MACH_TIMESPEC(&ts, &interval->ts) >= 0) {
+               /*
+                * New throttle window.
+                * Rollover any unused budget.
+                * Also ask the storage layer what the new budget needs to be.
+                */
+               uint64_t freeze_daily_budget = 0;
+               unsigned int daily_budget_pageouts = 0;
+
+               if (vm_swap_max_budget(&freeze_daily_budget)) {
+                       memorystatus_freeze_daily_mb_max = (freeze_daily_budget / (1024 * 1024));
+                       os_log_with_startup_serial(OS_LOG_DEFAULT, "memorystatus: memorystatus_freeze_daily_mb_max set to %dMB\n", memorystatus_freeze_daily_mb_max);
                }
+
+               freeze_daily_pageouts_max = memorystatus_freeze_daily_mb_max * (1024 * 1024 / PAGE_SIZE);
+
+               daily_budget_pageouts =  (interval->burst_multiple * (((uint64_t)interval->mins * freeze_daily_pageouts_max) / NORMAL_WINDOW_MINS));
+               interval->max_pageouts = (interval->max_pageouts - interval->pageouts) + daily_budget_pageouts;
+
                interval->ts.tv_sec = interval->mins * 60;
                interval->ts.tv_nsec = 0;
-               ADD_MACH_TIMESPEC(&interval->ts, ts);
+               ADD_MACH_TIMESPEC(&interval->ts, &ts);
                /* Since we update the throttle stats pre-freeze, adjust for overshoot here */
                if (interval->pageouts > interval->max_pageouts) {
                        interval->pageouts -= interval->max_pageouts;
                } else {
                        interval->pageouts = 0;
                }
-               interval->throttle = FALSE;
-       } else if (!interval->throttle && interval->pageouts >= interval->max_pageouts) {
-               printf("memorystatus_freeze_update_throttle_interval: %d minute pageout limit exceeded; enabling throttle\n", interval->mins);
-               interval->throttle = TRUE;
-       }       
+               *budget_pages_allowed = interval->max_pageouts;
+
+               memorystatus_demote_frozen_processes();
+       } else {
+               /*
+                * Current throttle window.
+                * Deny freezing if we have no budget left.
+                * Try graceful degradation if we are within 25% of:
+                * - the daily budget, and
+                * - the current budget left is below our normal budget expectations.
+                */
+
+#if DEVELOPMENT || DEBUG
+               /*
+                * This can only happen in the INTERNAL configs because we allow modifying the daily budget for testing.
+                */
+
+               if (freeze_daily_pageouts_max > interval->max_pageouts) {
+                       /*
+                        * We just bumped the daily budget. Re-evaluate our normal window params.
+                        */
+                       interval->max_pageouts = (interval->burst_multiple * (((uint64_t)interval->mins * freeze_daily_pageouts_max) / NORMAL_WINDOW_MINS));
+                       memorystatus_freeze_degradation = FALSE; //we'll re-evaluate this below...
+               }
+#endif /* DEVELOPMENT || DEBUG */
+
+               if (memorystatus_freeze_degradation == FALSE) {
+                       if (interval->pageouts >= interval->max_pageouts) {
+                               *budget_pages_allowed = 0;
+                       } else {
+                               int budget_left = interval->max_pageouts - interval->pageouts;
+                               int budget_threshold = (freeze_daily_pageouts_max * FREEZE_DEGRADATION_BUDGET_THRESHOLD) / 100;
+
+                               mach_timespec_t time_left = {0, 0};
+
+                               time_left.tv_sec = interval->ts.tv_sec;
+                               time_left.tv_nsec = 0;
+
+                               SUB_MACH_TIMESPEC(&time_left, &ts);
+
+                               if (budget_left <= budget_threshold) {
+                                       /*
+                                        * For the current normal window, calculate how much we would pageout in a DEGRADED_WINDOW_MINS duration.
+                                        * And also calculate what we would pageout for the same DEGRADED_WINDOW_MINS duration if we had the full
+                                        * daily pageout budget.
+                                        */
+
+                                       unsigned int current_budget_rate_allowed = ((budget_left / time_left.tv_sec) / 60) * DEGRADED_WINDOW_MINS;
+                                       unsigned int normal_budget_rate_allowed = (freeze_daily_pageouts_max / NORMAL_WINDOW_MINS) * DEGRADED_WINDOW_MINS;
+
+                                       /*
+                                        * The current rate of pageouts is below what we would expect for
+                                        * the normal rate i.e. we have below normal budget left and so...
+                                        */
+
+                                       if (current_budget_rate_allowed < normal_budget_rate_allowed) {
+                                               memorystatus_freeze_degradation = TRUE;
+                                               degraded_throttle_window->max_pageouts = current_budget_rate_allowed;
+                                               degraded_throttle_window->pageouts = 0;
+
+                                               /*
+                                                * Switch over to the degraded throttle window so the budget
+                                                * doled out is based on that window.
+                                                */
+                                               interval = degraded_throttle_window;
+                                       }
+                               }
+
+                               *budget_pages_allowed = interval->max_pageouts - interval->pageouts;
+                       }
+               }
+       }
+
+       MEMORYSTATUS_DEBUG(1, "memorystatus_freeze_update_throttle_interval: throttle updated - %d frozen (%d max) within %dm; %dm remaining; throttle %s\n",
+           interval->pageouts, interval->max_pageouts, interval->mins, (interval->ts.tv_sec - ts->tv_sec) / 60,
+           interval->throttle ? "on" : "off");
+}
+
+static void
+memorystatus_freeze_thread(void *param __unused, wait_result_t wr __unused)
+{
+       static boolean_t memorystatus_freeze_swap_low = FALSE;
+
+       lck_mtx_lock(&freezer_mutex);
+
+       if (memorystatus_freeze_enabled) {
+               if ((memorystatus_frozen_count < memorystatus_frozen_processes_max) ||
+                   (memorystatus_refreeze_eligible_count >= MIN_THAW_REFREEZE_THRESHOLD)) {
+                       if (memorystatus_can_freeze(&memorystatus_freeze_swap_low)) {
+                               /* Only freeze if we've not exceeded our pageout budgets.*/
+                               memorystatus_freeze_update_throttle(&memorystatus_freeze_budget_pages_remaining);
+
+                               if (memorystatus_freeze_budget_pages_remaining) {
+                                       memorystatus_freeze_top_process();
+                               }
+                       }
+               }
+       }
+
+       /*
+        * We use memorystatus_apps_idle_delay_time because if/when we adopt aging for applications,
+        * it'll tie neatly into running the freezer once we age an application.
+        *
+        * Till then, it serves as a good interval that can be tuned via a sysctl too.
+        */
+       memorystatus_freezer_thread_next_run_ts = mach_absolute_time() + memorystatus_apps_idle_delay_time;
+
+       assert_wait((event_t) &memorystatus_freeze_wakeup, THREAD_UNINT);
+       lck_mtx_unlock(&freezer_mutex);
 
-       MEMORYSTATUS_DEBUG(1, "memorystatus_freeze_update_throttle_interval: throttle updated - %d frozen (%d max) within %dm; %dm remaining; throttle %s\n", 
-               interval->pageouts, interval->max_pageouts, interval->mins, (interval->ts.tv_sec - ts->tv_sec) / 60, 
-               interval->throttle ? "on" : "off");
+       thread_block((thread_continue_t) memorystatus_freeze_thread);
 }
 
 static boolean_t
-memorystatus_freeze_update_throttle(void) 
+memorystatus_freeze_thread_should_run(void)
 {
-       clock_sec_t sec;
-       clock_nsec_t nsec;
-       mach_timespec_t ts;
-       uint32_t i;
-       boolean_t throttled = FALSE;
+       /*
+        * No freezer_mutex held here...see why near call-site
+        * within memorystatus_pages_update().
+        */
 
-#if DEVELOPMENT || DEBUG
-       if (!memorystatus_freeze_throttle_enabled)
-               return FALSE;
-#endif
+       boolean_t should_run = FALSE;
 
-       clock_get_system_nanotime(&sec, &nsec);
-       ts.tv_sec = sec;
-       ts.tv_nsec = nsec;
-       
-       /* Check freeze pageouts over multiple intervals and throttle if we've exceeded our budget.
-        *
-        * This ensures that periods of inactivity can't be used as 'credit' towards freeze if the device has
-        * remained dormant for a long period. We do, however, allow increased thresholds for shorter intervals in
-        * order to allow for bursts of activity.
-        */
-       for (i = 0; i < sizeof(throttle_intervals) / sizeof(struct throttle_interval_t); i++) {
-               memorystatus_freeze_update_throttle_interval(&ts, &throttle_intervals[i]);
-               if (throttle_intervals[i].throttle == TRUE)
-                       throttled = TRUE;
-       }                                                               
+       if (memorystatus_freeze_enabled == FALSE) {
+               goto out;
+       }
+
+       if (memorystatus_available_pages > memorystatus_freeze_threshold) {
+               goto out;
+       }
+
+       if ((memorystatus_frozen_count >= memorystatus_frozen_processes_max) &&
+           (memorystatus_refreeze_eligible_count < MIN_THAW_REFREEZE_THRESHOLD)) {
+               goto out;
+       }
+
+       if (memorystatus_frozen_shared_mb_max && (memorystatus_frozen_shared_mb >= memorystatus_frozen_shared_mb_max)) {
+               goto out;
+       }
+
+       uint64_t curr_time = mach_absolute_time();
+
+       if (curr_time < memorystatus_freezer_thread_next_run_ts) {
+               goto out;
+       }
+
+       should_run = TRUE;
 
-       return throttled;
+out:
+       return should_run;
 }
 
-static void
-memorystatus_freeze_thread(void *param __unused, wait_result_t wr __unused)
+static int
+sysctl_memorystatus_do_fastwake_warmup_all  SYSCTL_HANDLER_ARGS
 {
-       static boolean_t memorystatus_freeze_swap_low = FALSE;
+#pragma unused(oidp, req, arg1, arg2)
 
-       lck_mtx_lock(&freezer_mutex);
-       if (memorystatus_freeze_enabled) {
-               if (memorystatus_can_freeze(&memorystatus_freeze_swap_low)) {
-                       /* Only freeze if we've not exceeded our pageout budgets.*/
-                       if (!memorystatus_freeze_update_throttle()) {
-                               memorystatus_freeze_top_process(&memorystatus_freeze_swap_low);
-                       } else {
-                               printf("memorystatus_freeze_thread: in throttle, ignoring freeze\n");
-                               memorystatus_freeze_throttle_count++; /* Throttled, update stats */
-                       }
-               }
+       /* Need to be root or have entitlement */
+       if (!kauth_cred_issuser(kauth_cred_get()) && !IOTaskHasEntitlement(current_task(), MEMORYSTATUS_ENTITLEMENT)) {
+               return EPERM;
        }
-       lck_mtx_unlock(&freezer_mutex);
 
-       assert_wait((event_t) &memorystatus_freeze_wakeup, THREAD_UNINT);
-       thread_block((thread_continue_t) memorystatus_freeze_thread);   
+       if (memorystatus_freeze_enabled == FALSE) {
+               return ENOTSUP;
+       }
+
+       do_fastwake_warmup_all();
+
+       return 0;
 }
 
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_do_fastwake_warmup_all, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+    0, 0, &sysctl_memorystatus_do_fastwake_warmup_all, "I", "");
+
 #endif /* CONFIG_FREEZE */
 
 #if VM_PRESSURE_EVENTS
@@ -4255,10 +7485,11 @@ memorystatus_freeze_thread(void *param __unused, wait_result_t wr __unused)
 #if CONFIG_MEMORYSTATUS
 
 static int
-memorystatus_send_note(int event_code, void *data, size_t data_length) {
+memorystatus_send_note(int event_code, void *data, size_t data_length)
+{
        int ret;
        struct kev_msg ev_msg;
-       
+
        ev_msg.vendor_code    = KEV_VENDOR_APPLE;
        ev_msg.kev_class      = KEV_SYSTEM_CLASS;
        ev_msg.kev_subclass   = KEV_MEMORYSTATUS_SUBCLASS;
@@ -4273,16 +7504,17 @@ memorystatus_send_note(int event_code, void *data, size_t data_length) {
        if (ret) {
                printf("%s: kev_post_msg() failed, err %d\n", __func__, ret);
        }
-       
+
        return ret;
 }
 
 boolean_t
-memorystatus_warn_process(pid_t pid, boolean_t critical) {
-
+memorystatus_warn_process(pid_t pid, __unused boolean_t is_active, __unused boolean_t is_fatal, boolean_t limit_exceeded)
+{
        boolean_t ret = FALSE;
        boolean_t found_knote = FALSE;
        struct knote *kn = NULL;
+       int send_knote_count = 0;
 
        /*
         * See comment in sysctl_memorystatus_vm_pressure_send.
@@ -4291,7 +7523,7 @@ memorystatus_warn_process(pid_t pid, boolean_t critical) {
        memorystatus_klist_lock();
 
        SLIST_FOREACH(kn, &memorystatus_klist, kn_selnext) {
-               proc_t knote_proc = kn->kn_kq->kq_p;
+               proc_t knote_proc = knote_get_kq(kn)->kq_p;
                pid_t knote_pid = knote_proc->p_pid;
 
                if (knote_pid == pid) {
@@ -4303,30 +7535,142 @@ memorystatus_warn_process(pid_t pid, boolean_t critical) {
                         * system pressure snapshot evaluation in
                         * filt_memorystatus().
                         */
-       
-                       if (critical) {
-                               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_CRITICAL) {
+
+#if CONFIG_EMBEDDED
+                       if (!limit_exceeded) {
+                               /*
+                                * Intentionally set either the unambiguous limit warning,
+                                * the system-wide critical or the system-wide warning
+                                * notification bit.
+                                */
+
+                               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) {
+                                       kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_WARN;
+                                       found_knote = TRUE;
+                                       send_knote_count++;
+                               } else if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_CRITICAL) {
                                        kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_CRITICAL;
+                                       found_knote = TRUE;
+                                       send_knote_count++;
                                } else if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_WARN) {
                                        kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_WARN;
+                                       found_knote = TRUE;
+                                       send_knote_count++;
                                }
                        } else {
-                               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_WARN) {
-                                       kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_WARN;
+                               /*
+                                * Send this notification when a process has exceeded a soft limit.
+                                */
+                               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) {
+                                       kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL;
+                                       found_knote = TRUE;
+                                       send_knote_count++;
                                }
                        }
+#else /* CONFIG_EMBEDDED */
+                       if (!limit_exceeded) {
+                               /*
+                                * Processes on desktop are not expecting to handle a system-wide
+                                * critical or system-wide warning notification from this path.
+                                * Intentionally set only the unambiguous limit warning here.
+                                *
+                                * If the limit is soft, however, limit this to one notification per
+                                * active/inactive limit (per each registered listener).
+                                */
 
-                       found_knote = TRUE;
+                               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) {
+                                       found_knote = TRUE;
+                                       if (!is_fatal) {
+                                               /*
+                                                * Restrict proc_limit_warn notifications when
+                                                * non-fatal (soft) limit is at play.
+                                                */
+                                               if (is_active) {
+                                                       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_ACTIVE) {
+                                                               /*
+                                                                * Mark this knote for delivery.
+                                                                */
+                                                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_WARN;
+                                                               /*
+                                                                * And suppress it from future notifications.
+                                                                */
+                                                               kn->kn_sfflags &= ~NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_ACTIVE;
+                                                               send_knote_count++;
+                                                       }
+                                               } else {
+                                                       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_INACTIVE) {
+                                                               /*
+                                                                * Mark this knote for delivery.
+                                                                */
+                                                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_WARN;
+                                                               /*
+                                                                * And suppress it from future notifications.
+                                                                */
+                                                               kn->kn_sfflags &= ~NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_INACTIVE;
+                                                               send_knote_count++;
+                                                       }
+                                               }
+                                       } else {
+                                               /*
+                                                * No restriction on proc_limit_warn notifications when
+                                                * fatal (hard) limit is at play.
+                                                */
+                                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_WARN;
+                                               send_knote_count++;
+                                       }
+                               }
+                       } else {
+                               /*
+                                * Send this notification when a process has exceeded a soft limit,
+                                */
+
+                               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) {
+                                       found_knote = TRUE;
+                                       if (!is_fatal) {
+                                               /*
+                                                * Restrict critical notifications for soft limits.
+                                                */
+
+                                               if (is_active) {
+                                                       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_ACTIVE) {
+                                                               /*
+                                                                * Suppress future proc_limit_critical notifications
+                                                                * for the active soft limit.
+                                                                */
+                                                               kn->kn_sfflags &= ~NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_ACTIVE;
+                                                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL;
+                                                               send_knote_count++;
+                                                       }
+                                               } else {
+                                                       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_INACTIVE) {
+                                                               /*
+                                                                * Suppress future proc_limit_critical_notifications
+                                                                * for the inactive soft limit.
+                                                                */
+                                                               kn->kn_sfflags &= ~NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_INACTIVE;
+                                                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL;
+                                                               send_knote_count++;
+                                                       }
+                                               }
+                                       } else {
+                                               /*
+                                                * We should never be trying to send a critical notification for
+                                                * a hard limit... the process would be killed before it could be
+                                                * received.
+                                                */
+                                               panic("Caught sending pid %d a critical warning for a fatal limit.\n", pid);
+                                       }
+                               }
+                       }
+#endif /* CONFIG_EMBEDDED */
                }
        }
 
        if (found_knote) {
-               KNOTE(&memorystatus_klist, 0);
-               ret = TRUE;
-       } else {
-               if (vm_dispatch_pressure_note_to_pid(pid, FALSE) == 0) {
-                       ret = TRUE;
+               if (send_knote_count > 0) {
+                       KNOTE(&memorystatus_klist, 0);
                }
+               ret = TRUE;
        }
 
        memorystatus_klist_unlock();
@@ -4352,18 +7696,19 @@ memorystatus_low_mem_privileged_listener(uint32_t op_flags)
                return EINVAL;
        }
 
-       return (task_low_mem_privileged_listener(current_task(), set_privilege, NULL));
+       return task_low_mem_privileged_listener(current_task(), set_privilege, NULL);
 }
 
 int
-memorystatus_send_pressure_note(pid_t pid) {
-       MEMORYSTATUS_DEBUG(1, "memorystatus_send_pressure_note(): pid %d\n", pid);      
-       return memorystatus_send_note(kMemorystatusPressureNote, &pid, sizeof(pid));
+memorystatus_send_pressure_note(pid_t pid)
+{
+       MEMORYSTATUS_DEBUG(1, "memorystatus_send_pressure_note(): pid %d\n", pid);
+       return memorystatus_send_note(kMemorystatusPressureNote, &pid, sizeof(pid));
 }
 
 void
-memorystatus_send_low_swap_note(void) {
-       
+memorystatus_send_low_swap_note(void)
+{
        struct knote *kn = NULL;
 
        memorystatus_klist_lock();
@@ -4382,60 +7727,96 @@ memorystatus_send_low_swap_note(void) {
 }
 
 boolean_t
-memorystatus_bg_pressure_eligible(proc_t p) {
-       boolean_t eligible = FALSE;
-        
+memorystatus_bg_pressure_eligible(proc_t p)
+{
+       boolean_t eligible = FALSE;
+
        proc_list_lock();
-       
+
        MEMORYSTATUS_DEBUG(1, "memorystatus_bg_pressure_eligible: pid %d, state 0x%x\n", p->p_pid, p->p_memstat_state);
-        
-       /* Foreground processes have already been dealt with at this point, so just test for eligibility */
-       if (!(p->p_memstat_state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_SUSPENDED | P_MEMSTAT_FROZEN))) {
-                eligible = TRUE;
+
+       /* Foreground processes have already been dealt with at this point, so just test for eligibility */
+       if (!(p->p_memstat_state & (P_MEMSTAT_TERMINATED | P_MEMSTAT_LOCKED | P_MEMSTAT_SUSPENDED | P_MEMSTAT_FROZEN))) {
+               eligible = TRUE;
+       }
+
+       if (p->p_memstat_effectivepriority < JETSAM_PRIORITY_BACKGROUND_OPPORTUNISTIC) {
+               /*
+                * IDLE and IDLE_DEFERRED bands contain processes
+                * that have dropped memory to be under their inactive
+                * memory limits. And so they can't really give back
+                * anything.
+                */
+               eligible = FALSE;
        }
-        
+
        proc_list_unlock();
-       
-       return eligible;
+
+       return eligible;
 }
 
 boolean_t
-memorystatus_is_foreground_locked(proc_t p) {
-        return ((p->p_memstat_effectivepriority == JETSAM_PRIORITY_FOREGROUND) || 
-                (p->p_memstat_effectivepriority == JETSAM_PRIORITY_FOREGROUND_SUPPORT));
+memorystatus_is_foreground_locked(proc_t p)
+{
+       return (p->p_memstat_effectivepriority == JETSAM_PRIORITY_FOREGROUND) ||
+              (p->p_memstat_effectivepriority == JETSAM_PRIORITY_FOREGROUND_SUPPORT);
+}
+
+/*
+ * This is meant for stackshot and kperf -- it does not take the proc_list_lock
+ * to access the p_memstat_dirty field.
+ */
+void
+memorystatus_proc_flags_unsafe(void * v, boolean_t *is_dirty, boolean_t *is_dirty_tracked, boolean_t *allow_idle_exit)
+{
+       if (!v) {
+               *is_dirty = FALSE;
+               *is_dirty_tracked = FALSE;
+               *allow_idle_exit = FALSE;
+       } else {
+               proc_t p = (proc_t)v;
+               *is_dirty = (p->p_memstat_dirty & P_DIRTY_IS_DIRTY) != 0;
+               *is_dirty_tracked = (p->p_memstat_dirty & P_DIRTY_TRACK) != 0;
+               *allow_idle_exit = (p->p_memstat_dirty & P_DIRTY_ALLOW_IDLE_EXIT) != 0;
+       }
 }
+
 #endif /* CONFIG_MEMORYSTATUS */
 
 /*
  * Trigger levels to test the mechanism.
  * Can be used via a sysctl.
  */
-#define TEST_LOW_MEMORY_TRIGGER_ONE            1
-#define TEST_LOW_MEMORY_TRIGGER_ALL            2
-#define TEST_PURGEABLE_TRIGGER_ONE             3
-#define TEST_PURGEABLE_TRIGGER_ALL             4
-#define TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ONE  5
-#define TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ALL  6
+#define TEST_LOW_MEMORY_TRIGGER_ONE             1
+#define TEST_LOW_MEMORY_TRIGGER_ALL             2
+#define TEST_PURGEABLE_TRIGGER_ONE              3
+#define TEST_PURGEABLE_TRIGGER_ALL              4
+#define TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ONE   5
+#define TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ALL   6
 
-boolean_t              memorystatus_manual_testing_on = FALSE;
-vm_pressure_level_t    memorystatus_manual_testing_level = kVMPressureNormal;
+boolean_t               memorystatus_manual_testing_on = FALSE;
+vm_pressure_level_t     memorystatus_manual_testing_level = kVMPressureNormal;
 
 extern struct knote *
 vm_pressure_select_optimal_candidate_to_notify(struct klist *, int, boolean_t);
 
-extern
-kern_return_t vm_pressure_notification_without_levels(boolean_t);
 
-extern void vm_pressure_klist_lock(void);
-extern void vm_pressure_klist_unlock(void);
+#define VM_PRESSURE_NOTIFY_WAIT_PERIOD          10000   /* milliseconds */
 
-extern void vm_reset_active_list(void);
-
-extern void delay(int);
+#if DEBUG
+#define VM_PRESSURE_DEBUG(cond, format, ...)      \
+do {                                              \
+       if (cond) { printf(format, ##__VA_ARGS__); } \
+} while(0)
+#else
+#define VM_PRESSURE_DEBUG(cond, format, ...)
+#endif
 
-#define INTER_NOTIFICATION_DELAY       (250000)        /* .25 second */
+#define INTER_NOTIFICATION_DELAY        (250000)        /* .25 second */
 
-void memorystatus_on_pageout_scan_end(void) {
+void
+memorystatus_on_pageout_scan_end(void)
+{
        /* No-op */
 }
 
@@ -4456,45 +7837,297 @@ boolean_t
 is_knote_registered_modify_task_pressure_bits(struct knote *kn_max, int knote_pressure_level, task_t task, vm_pressure_level_t pressure_level_to_clear, vm_pressure_level_t pressure_level_to_set)
 {
        if (kn_max->kn_sfflags & knote_pressure_level) {
+               if (pressure_level_to_clear && task_has_been_notified(task, pressure_level_to_clear) == TRUE) {
+                       task_clear_has_been_notified(task, pressure_level_to_clear);
+               }
 
-               if (task_has_been_notified(task, pressure_level_to_clear) == TRUE) {
+               task_mark_has_been_notified(task, pressure_level_to_set);
+               return TRUE;
+       }
 
-                       task_clear_has_been_notified(task, pressure_level_to_clear);
+       return FALSE;
+}
+
+void
+memorystatus_klist_reset_all_for_level(vm_pressure_level_t pressure_level_to_clear)
+{
+       struct knote *kn = NULL;
+
+       memorystatus_klist_lock();
+       SLIST_FOREACH(kn, &memorystatus_klist, kn_selnext) {
+               proc_t                  p = PROC_NULL;
+               struct task*            t = TASK_NULL;
+
+               p = knote_get_kq(kn)->kq_p;
+               proc_list_lock();
+               if (p != proc_ref_locked(p)) {
+                       p = PROC_NULL;
+                       proc_list_unlock();
+                       continue;
+               }
+               proc_list_unlock();
+
+               t = (struct task *)(p->task);
+
+               task_clear_has_been_notified(t, pressure_level_to_clear);
+
+               proc_rele(p);
+       }
+
+       memorystatus_klist_unlock();
+}
+
+extern kern_return_t vm_pressure_notify_dispatch_vm_clients(boolean_t target_foreground_process);
+
+struct knote *
+vm_pressure_select_optimal_candidate_to_notify(struct klist *candidate_list, int level, boolean_t target_foreground_process);
+
+/*
+ * Used by the vm_pressure_thread which is
+ * signalled from within vm_pageout_scan().
+ */
+static void vm_dispatch_memory_pressure(void);
+void consider_vm_pressure_events(void);
+
+void
+consider_vm_pressure_events(void)
+{
+       vm_dispatch_memory_pressure();
+}
+static void
+vm_dispatch_memory_pressure(void)
+{
+       memorystatus_update_vm_pressure(FALSE);
+}
+
+extern vm_pressure_level_t
+convert_internal_pressure_level_to_dispatch_level(vm_pressure_level_t);
+
+struct knote *
+vm_pressure_select_optimal_candidate_to_notify(struct klist *candidate_list, int level, boolean_t target_foreground_process)
+{
+       struct knote    *kn = NULL, *kn_max = NULL;
+       uint64_t        resident_max = 0;       /* MB */
+       struct timeval  curr_tstamp = {0, 0};
+       int             elapsed_msecs = 0;
+       int             selected_task_importance = 0;
+       static int      pressure_snapshot = -1;
+       boolean_t       pressure_increase = FALSE;
+
+       if (pressure_snapshot == -1) {
+               /*
+                * Initial snapshot.
+                */
+               pressure_snapshot = level;
+               pressure_increase = TRUE;
+       } else {
+               if (level && (level >= pressure_snapshot)) {
+                       pressure_increase = TRUE;
+               } else {
+                       pressure_increase = FALSE;
+               }
+
+               pressure_snapshot = level;
+       }
+
+       if (pressure_increase == TRUE) {
+               /*
+                * We'll start by considering the largest
+                * unimportant task in our list.
+                */
+               selected_task_importance = INT_MAX;
+       } else {
+               /*
+                * We'll start by considering the largest
+                * important task in our list.
+                */
+               selected_task_importance = 0;
+       }
+
+       microuptime(&curr_tstamp);
+
+       SLIST_FOREACH(kn, candidate_list, kn_selnext) {
+               uint64_t                resident_size = 0;      /* MB */
+               proc_t                  p = PROC_NULL;
+               struct task*            t = TASK_NULL;
+               int                     curr_task_importance = 0;
+               boolean_t               consider_knote = FALSE;
+               boolean_t               privileged_listener = FALSE;
+
+               p = knote_get_kq(kn)->kq_p;
+               proc_list_lock();
+               if (p != proc_ref_locked(p)) {
+                       p = PROC_NULL;
+                       proc_list_unlock();
+                       continue;
+               }
+               proc_list_unlock();
+
+#if CONFIG_MEMORYSTATUS
+               if (target_foreground_process == TRUE && !memorystatus_is_foreground_locked(p)) {
+                       /*
+                        * Skip process not marked foreground.
+                        */
+                       proc_rele(p);
+                       continue;
+               }
+#endif /* CONFIG_MEMORYSTATUS */
+
+               t = (struct task *)(p->task);
+
+               timevalsub(&curr_tstamp, &p->vm_pressure_last_notify_tstamp);
+               elapsed_msecs = curr_tstamp.tv_sec * 1000 + curr_tstamp.tv_usec / 1000;
+
+               vm_pressure_level_t dispatch_level = convert_internal_pressure_level_to_dispatch_level(level);
+
+               if ((kn->kn_sfflags & dispatch_level) == 0) {
+                       proc_rele(p);
+                       continue;
+               }
+
+#if CONFIG_MEMORYSTATUS
+               if (target_foreground_process == FALSE && !memorystatus_bg_pressure_eligible(p)) {
+                       VM_PRESSURE_DEBUG(1, "[vm_pressure] skipping process %d\n", p->p_pid);
+                       proc_rele(p);
+                       continue;
+               }
+#endif /* CONFIG_MEMORYSTATUS */
+
+#if CONFIG_EMBEDDED
+               curr_task_importance = p->p_memstat_effectivepriority;
+#else /* CONFIG_EMBEDDED */
+               curr_task_importance = task_importance_estimate(t);
+#endif /* CONFIG_EMBEDDED */
+
+               /*
+                * Privileged listeners are only considered in the multi-level pressure scheme
+                * AND only if the pressure is increasing.
+                */
+               if (level > 0) {
+                       if (task_has_been_notified(t, level) == FALSE) {
+                               /*
+                                * Is this a privileged listener?
+                                */
+                               if (task_low_mem_privileged_listener(t, FALSE, &privileged_listener) == 0) {
+                                       if (privileged_listener) {
+                                               kn_max = kn;
+                                               proc_rele(p);
+                                               goto done_scanning;
+                                       }
+                               }
+                       } else {
+                               proc_rele(p);
+                               continue;
+                       }
+               } else if (level == 0) {
+                       /*
+                        * Task wasn't notified when the pressure was increasing and so
+                        * no need to notify it that the pressure is decreasing.
+                        */
+                       if ((task_has_been_notified(t, kVMPressureWarning) == FALSE) && (task_has_been_notified(t, kVMPressureCritical) == FALSE)) {
+                               proc_rele(p);
+                               continue;
+                       }
+               }
+
+               /*
+                * We don't want a small process to block large processes from
+                * being notified again. <rdar://problem/7955532>
+                */
+               resident_size = (get_task_phys_footprint(t)) / (1024 * 1024ULL);  /* MB */
+
+               if (resident_size >= vm_pressure_task_footprint_min) {
+                       if (level > 0) {
+                               /*
+                                * Warning or Critical Pressure.
+                                */
+                               if (pressure_increase) {
+                                       if ((curr_task_importance < selected_task_importance) ||
+                                           ((curr_task_importance == selected_task_importance) && (resident_size > resident_max))) {
+                                               /*
+                                                * We have found a candidate process which is:
+                                                * a) at a lower importance than the current selected process
+                                                * OR
+                                                * b) has importance equal to that of the current selected process but is larger
+                                                */
+
+                                               consider_knote = TRUE;
+                                       }
+                               } else {
+                                       if ((curr_task_importance > selected_task_importance) ||
+                                           ((curr_task_importance == selected_task_importance) && (resident_size > resident_max))) {
+                                               /*
+                                                * We have found a candidate process which is:
+                                                * a) at a higher importance than the current selected process
+                                                * OR
+                                                * b) has importance equal to that of the current selected process but is larger
+                                                */
+
+                                               consider_knote = TRUE;
+                                       }
+                               }
+                       } else if (level == 0) {
+                               /*
+                                * Pressure back to normal.
+                                */
+                               if ((curr_task_importance > selected_task_importance) ||
+                                   ((curr_task_importance == selected_task_importance) && (resident_size > resident_max))) {
+                                       consider_knote = TRUE;
+                               }
+                       }
+
+                       if (consider_knote) {
+                               resident_max = resident_size;
+                               kn_max = kn;
+                               selected_task_importance = curr_task_importance;
+                               consider_knote = FALSE; /* reset for the next candidate */
+                       }
+               } else {
+                       /* There was no candidate with enough resident memory to scavenge */
+                       VM_PRESSURE_DEBUG(0, "[vm_pressure] threshold failed for pid %d with %llu resident...\n", p->p_pid, resident_size);
                }
+               proc_rele(p);
+       }
 
-               task_mark_has_been_notified(task, pressure_level_to_set);
-               return TRUE;
+done_scanning:
+       if (kn_max) {
+               VM_DEBUG_CONSTANT_EVENT(vm_pressure_event, VM_PRESSURE_EVENT, DBG_FUNC_NONE, knote_get_kq(kn_max)->kq_p->p_pid, resident_max, 0, 0);
+               VM_PRESSURE_DEBUG(1, "[vm_pressure] sending event to pid %d with %llu resident\n", knote_get_kq(kn_max)->kq_p->p_pid, resident_max);
        }
 
-       return FALSE;
+       return kn_max;
 }
 
-extern kern_return_t vm_pressure_notify_dispatch_vm_clients(boolean_t target_foreground_process);
+#define VM_PRESSURE_DECREASED_SMOOTHING_PERIOD          5000    /* milliseconds */
+#define WARNING_NOTIFICATION_RESTING_PERIOD             25      /* seconds */
+#define CRITICAL_NOTIFICATION_RESTING_PERIOD            25      /* seconds */
 
-#define VM_PRESSURE_DECREASED_SMOOTHING_PERIOD         5000    /* milliseconds */
+uint64_t next_warning_notification_sent_at_ts = 0;
+uint64_t next_critical_notification_sent_at_ts = 0;
 
 kern_return_t
-memorystatus_update_vm_pressure(boolean_t target_foreground_process) 
-{
-       struct knote                    *kn_max = NULL;
-       struct knote                    *kn_cur = NULL, *kn_temp = NULL;  /* for safe list traversal */
-        pid_t                          target_pid = -1;
-        struct klist                   dispatch_klist = { NULL };
-       proc_t                          target_proc = PROC_NULL;
-       struct task                     *task = NULL;
-       boolean_t                       found_candidate = FALSE;
-
-       static vm_pressure_level_t      level_snapshot = kVMPressureNormal;
-       static vm_pressure_level_t      prev_level_snapshot = kVMPressureNormal;
-       boolean_t                       smoothing_window_started = FALSE;
-       struct timeval                  smoothing_window_start_tstamp = {0, 0};
-       struct timeval                  curr_tstamp = {0, 0};
-       int                             elapsed_msecs = 0;
+memorystatus_update_vm_pressure(boolean_t target_foreground_process)
+{
+       struct knote                    *kn_max = NULL;
+       struct knote                    *kn_cur = NULL, *kn_temp = NULL;  /* for safe list traversal */
+       pid_t                           target_pid = -1;
+       struct klist                    dispatch_klist = { NULL };
+       proc_t                          target_proc = PROC_NULL;
+       struct task                     *task = NULL;
+       boolean_t                       found_candidate = FALSE;
+
+       static vm_pressure_level_t      level_snapshot = kVMPressureNormal;
+       static vm_pressure_level_t      prev_level_snapshot = kVMPressureNormal;
+       boolean_t                       smoothing_window_started = FALSE;
+       struct timeval                  smoothing_window_start_tstamp = {0, 0};
+       struct timeval                  curr_tstamp = {0, 0};
+       int                             elapsed_msecs = 0;
+       uint64_t                        curr_ts = mach_absolute_time();
 
 #if !CONFIG_JETSAM
-#define MAX_IDLE_KILLS 100     /* limit the number of idle kills allowed */
+#define MAX_IDLE_KILLS 100      /* limit the number of idle kills allowed */
 
-       int     idle_kill_counter = 0;
+       int     idle_kill_counter = 0;
 
        /*
         * On desktop we take this opportunity to free up memory pressure
@@ -4520,8 +8153,38 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
        }
 #endif /* !CONFIG_JETSAM */
 
+       if (level_snapshot != kVMPressureNormal) {
+               /*
+                * Check to see if we are still in the 'resting' period
+                * after having notified all clients interested in
+                * a particular pressure level.
+                */
+
+               level_snapshot = memorystatus_vm_pressure_level;
+
+               if (level_snapshot == kVMPressureWarning || level_snapshot == kVMPressureUrgent) {
+                       if (next_warning_notification_sent_at_ts) {
+                               if (curr_ts < next_warning_notification_sent_at_ts) {
+                                       delay(INTER_NOTIFICATION_DELAY * 4 /* 1 sec */);
+                                       return KERN_SUCCESS;
+                               }
+
+                               next_warning_notification_sent_at_ts = 0;
+                               memorystatus_klist_reset_all_for_level(kVMPressureWarning);
+                       }
+               } else if (level_snapshot == kVMPressureCritical) {
+                       if (next_critical_notification_sent_at_ts) {
+                               if (curr_ts < next_critical_notification_sent_at_ts) {
+                                       delay(INTER_NOTIFICATION_DELAY * 4 /* 1 sec */);
+                                       return KERN_SUCCESS;
+                               }
+                               next_critical_notification_sent_at_ts = 0;
+                               memorystatus_klist_reset_all_for_level(kVMPressureCritical);
+                       }
+               }
+       }
+
        while (1) {
-       
                /*
                 * There is a race window here. But it's not clear
                 * how much we benefit from having extra synchronization.
@@ -4534,7 +8197,6 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
                         * and see if this condition stays.
                         */
                        if (smoothing_window_started == FALSE) {
-
                                smoothing_window_started = TRUE;
                                microuptime(&smoothing_window_start_tstamp);
                        }
@@ -4544,7 +8206,6 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
                        elapsed_msecs = curr_tstamp.tv_sec * 1000 + curr_tstamp.tv_usec / 1000;
 
                        if (elapsed_msecs < VM_PRESSURE_DECREASED_SMOOTHING_PERIOD) {
-                       
                                delay(INTER_NOTIFICATION_DELAY);
                                continue;
                        }
@@ -4556,30 +8217,35 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
                memorystatus_klist_lock();
                kn_max = vm_pressure_select_optimal_candidate_to_notify(&memorystatus_klist, level_snapshot, target_foreground_process);
 
-               if (kn_max == NULL) {
+               if (kn_max == NULL) {
                        memorystatus_klist_unlock();
 
                        /*
                         * No more level-based clients to notify.
-                        * Try the non-level based notification clients.
-                        *      
-                        * However, these non-level clients don't understand
-                        * the "return-to-normal" notification.
-                        *
-                        * So don't consider them for those notifications. Just
-                        * return instead.
                         *
+                        * Start the 'resting' window within which clients will not be re-notified.
                         */
 
                        if (level_snapshot != kVMPressureNormal) {
-                               goto try_dispatch_vm_clients;
-                       } else {
-                               return KERN_FAILURE;
-                       }       
+                               if (level_snapshot == kVMPressureWarning || level_snapshot == kVMPressureUrgent) {
+                                       nanoseconds_to_absolutetime(WARNING_NOTIFICATION_RESTING_PERIOD * NSEC_PER_SEC, &curr_ts);
+
+                                       /* Next warning notification (if nothing changes) won't be sent before...*/
+                                       next_warning_notification_sent_at_ts = mach_absolute_time() + curr_ts;
+                               }
+
+                               if (level_snapshot == kVMPressureCritical) {
+                                       nanoseconds_to_absolutetime(CRITICAL_NOTIFICATION_RESTING_PERIOD * NSEC_PER_SEC, &curr_ts);
+
+                                       /* Next critical notification (if nothing changes) won't be sent before...*/
+                                       next_critical_notification_sent_at_ts = mach_absolute_time() + curr_ts;
+                               }
+                       }
+                       return KERN_FAILURE;
                }
-               
-               target_proc = kn_max->kn_kq->kq_p;
-               
+
+               target_proc = knote_get_kq(kn_max)->kq_p;
+
                proc_list_lock();
                if (target_proc != proc_ref_locked(target_proc)) {
                        target_proc = PROC_NULL;
@@ -4588,29 +8254,25 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
                        continue;
                }
                proc_list_unlock();
-               
+
                target_pid = target_proc->p_pid;
 
                task = (struct task *)(target_proc->task);
-       
-               if (level_snapshot != kVMPressureNormal) {
 
+               if (level_snapshot != kVMPressureNormal) {
                        if (level_snapshot == kVMPressureWarning || level_snapshot == kVMPressureUrgent) {
-
-                               if (is_knote_registered_modify_task_pressure_bits(kn_max, NOTE_MEMORYSTATUS_PRESSURE_WARN, task, kVMPressureCritical, kVMPressureWarning) == TRUE) {
+                               if (is_knote_registered_modify_task_pressure_bits(kn_max, NOTE_MEMORYSTATUS_PRESSURE_WARN, task, 0, kVMPressureWarning) == TRUE) {
                                        found_candidate = TRUE;
                                }
                        } else {
                                if (level_snapshot == kVMPressureCritical) {
-                               
-                                       if (is_knote_registered_modify_task_pressure_bits(kn_max, NOTE_MEMORYSTATUS_PRESSURE_CRITICAL, task, kVMPressureWarning, kVMPressureCritical) == TRUE) {
+                                       if (is_knote_registered_modify_task_pressure_bits(kn_max, NOTE_MEMORYSTATUS_PRESSURE_CRITICAL, task, 0, kVMPressureCritical) == TRUE) {
                                                found_candidate = TRUE;
                                        }
                                }
                        }
                } else {
                        if (kn_max->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_NORMAL) {
-
                                task_clear_has_been_notified(task, kVMPressureWarning);
                                task_clear_has_been_notified(task, kVMPressureCritical);
 
@@ -4625,11 +8287,15 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
                }
 
                SLIST_FOREACH_SAFE(kn_cur, &memorystatus_klist, kn_selnext, kn_temp) {
-                       proc_t knote_proc = kn_cur->kn_kq->kq_p;
-                       pid_t knote_pid = knote_proc->p_pid;
-                       if (knote_pid == target_pid) {
-                               KNOTE_DETACH(&memorystatus_klist, kn_cur);
-                               KNOTE_ATTACH(&dispatch_klist, kn_cur);
+                       int knote_pressure_level = convert_internal_pressure_level_to_dispatch_level(level_snapshot);
+
+                       if (is_knote_registered_modify_task_pressure_bits(kn_cur, knote_pressure_level, task, 0, level_snapshot) == TRUE) {
+                               proc_t knote_proc = knote_get_kq(kn_cur)->kq_p;
+                               pid_t knote_pid = knote_proc->p_pid;
+                               if (knote_pid == target_pid) {
+                                       KNOTE_DETACH(&memorystatus_klist, kn_cur);
+                                       KNOTE_ATTACH(&dispatch_klist, kn_cur);
+                               }
                        }
                }
 
@@ -4649,48 +8315,19 @@ memorystatus_update_vm_pressure(boolean_t target_foreground_process)
                        break;
                }
 
-try_dispatch_vm_clients:
-               if (kn_max == NULL && level_snapshot != kVMPressureNormal) {
-                       /*
-                        * We will exit this loop when we are done with
-                        * notification clients (level and non-level based).
-                        */
-                       if ((vm_pressure_notify_dispatch_vm_clients(target_foreground_process) == KERN_FAILURE) && (kn_max == NULL)) {
-                               /*
-                                * kn_max == NULL i.e. we didn't find any eligible clients for the level-based notifications
-                                * AND
-                                * we have failed to find any eligible clients for the non-level based notifications too.
-                                * So, we are done.
-                                */
-
-                               return KERN_FAILURE;
-                       }
-               }
-
-               /*
-                * LD: This block of code below used to be invoked in the older memory notification scheme on embedded everytime 
-                * a process was sent a memory pressure notification. The "memorystatus_klist" list was used to hold these
-                * privileged listeners. But now we have moved to the newer scheme and are trying to move away from the extra
-                * notifications. So the code is here in case we break compat. and need to send out notifications to the privileged
-                * apps.
-                */
-#if 0
-#endif /* 0 */
-
                if (memorystatus_manual_testing_on == TRUE) {
                        /*
                         * Testing out the pressure notification scheme.
                         * No need for delays etc.
                         */
                } else {
-
                        uint32_t sleep_interval = INTER_NOTIFICATION_DELAY;
 #if CONFIG_JETSAM
                        unsigned int page_delta = 0;
                        unsigned int skip_delay_page_threshold = 0;
 
                        assert(memorystatus_available_pages_pressure >= memorystatus_available_pages_critical_base);
-                       
+
                        page_delta = (memorystatus_available_pages_pressure - memorystatus_available_pages_critical_base) / 2;
                        skip_delay_page_threshold = memorystatus_available_pages_pressure - page_delta;
 
@@ -4702,7 +8339,7 @@ try_dispatch_vm_clients:
                                sleep_interval = 0;
                        }
 #endif /* CONFIG_JETSAM */
-                               
+
                        if (sleep_interval) {
                                delay(sleep_interval);
                        }
@@ -4712,37 +8349,33 @@ try_dispatch_vm_clients:
        return KERN_SUCCESS;
 }
 
-vm_pressure_level_t
-convert_internal_pressure_level_to_dispatch_level(vm_pressure_level_t);
-
 vm_pressure_level_t
 convert_internal_pressure_level_to_dispatch_level(vm_pressure_level_t internal_pressure_level)
 {
-       vm_pressure_level_t     dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_NORMAL;
-       
-       switch (internal_pressure_level) {
+       vm_pressure_level_t     dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_NORMAL;
 
-               case kVMPressureNormal:
-               {
-                       dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_NORMAL;
-                       break;
-               }
+       switch (internal_pressure_level) {
+       case kVMPressureNormal:
+       {
+               dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_NORMAL;
+               break;
+       }
 
-               case kVMPressureWarning:
-               case kVMPressureUrgent:
-               {
-                       dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_WARN;
-                       break;
-               }
+       case kVMPressureWarning:
+       case kVMPressureUrgent:
+       {
+               dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_WARN;
+               break;
+       }
 
-               case kVMPressureCritical:
-               {
-                       dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_CRITICAL;
-                       break;
-               }
+       case kVMPressureCritical:
+       {
+               dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_CRITICAL;
+               break;
+       }
 
-               default:
-                       break;
+       default:
+               break;
        }
 
        return dispatch_level;
@@ -4752,6 +8385,15 @@ static int
 sysctl_memorystatus_vm_pressure_level SYSCTL_HANDLER_ARGS
 {
 #pragma unused(arg1, arg2, oidp)
+#if CONFIG_EMBEDDED
+       int error = 0;
+
+       error = priv_check_cred(kauth_cred_get(), PRIV_VM_PRESSURE, 0);
+       if (error) {
+               return error;
+       }
+
+#endif /* CONFIG_EMBEDDED */
        vm_pressure_level_t dispatch_level = convert_internal_pressure_level_to_dispatch_level(memorystatus_vm_pressure_level);
 
        return SYSCTL_OUT(req, &dispatch_level, sizeof(dispatch_level));
@@ -4759,18 +8401,16 @@ sysctl_memorystatus_vm_pressure_level SYSCTL_HANDLER_ARGS
 
 #if DEBUG || DEVELOPMENT
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_level, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_LOCKED,
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_level, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED,
     0, 0, &sysctl_memorystatus_vm_pressure_level, "I", "");
 
 #else /* DEBUG || DEVELOPMENT */
 
-SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_level, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_LOCKED|CTLFLAG_MASKED,
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_level, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED | CTLFLAG_MASKED,
     0, 0, &sysctl_memorystatus_vm_pressure_level, "I", "");
 
 #endif /* DEBUG || DEVELOPMENT */
 
-extern int memorystatus_purge_on_warning;
-extern int memorystatus_purge_on_critical;
 
 static int
 sysctl_memorypressure_manual_trigger SYSCTL_HANDLER_ARGS
@@ -4785,13 +8425,13 @@ sysctl_memorypressure_manual_trigger SYSCTL_HANDLER_ARGS
 
        error = sysctl_handle_int(oidp, &level, 0, req);
        if (error || !req->newptr) {
-               return (error);
+               return error;
        }
 
        memorystatus_manual_testing_on = TRUE;
 
        trigger_request = (level >> 16) & 0xFFFF;
-       pressure_level = (level & 0xFFFF); 
+       pressure_level = (level & 0xFFFF);
 
        if (trigger_request < TEST_LOW_MEMORY_TRIGGER_ONE ||
            trigger_request > TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ALL) {
@@ -4812,19 +8452,14 @@ sysctl_memorypressure_manual_trigger SYSCTL_HANDLER_ARGS
         * So we translate those events to our internal levels here.
         */
        if (pressure_level == NOTE_MEMORYSTATUS_PRESSURE_NORMAL) {
-
                memorystatus_manual_testing_level = kVMPressureNormal;
                force_purge = 0;
-
        } else if (pressure_level == NOTE_MEMORYSTATUS_PRESSURE_WARN) {
-
                memorystatus_manual_testing_level = kVMPressureWarning;
-               force_purge = memorystatus_purge_on_warning;
-
+               force_purge = vm_pageout_state.memorystatus_purge_on_warning;
        } else if (pressure_level == NOTE_MEMORYSTATUS_PRESSURE_CRITICAL) {
-
                memorystatus_manual_testing_level = kVMPressureCritical;
-               force_purge = memorystatus_purge_on_critical;
+               force_purge = vm_pageout_state.memorystatus_purge_on_critical;
        }
 
        memorystatus_vm_pressure_level = memorystatus_manual_testing_level;
@@ -4845,78 +8480,68 @@ sysctl_memorypressure_manual_trigger SYSCTL_HANDLER_ARGS
                        /* no purging requested */
                        break;
                }
-               while (vm_purgeable_object_purge_one_unlocked(force_purge));
+               while (vm_purgeable_object_purge_one_unlocked(force_purge)) {
+                       ;
+               }
                break;
        }
 
        if ((trigger_request == TEST_LOW_MEMORY_TRIGGER_ONE) ||
            (trigger_request == TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ONE)) {
-
                memorystatus_update_vm_pressure(TRUE);
        }
 
        if ((trigger_request == TEST_LOW_MEMORY_TRIGGER_ALL) ||
            (trigger_request == TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ALL)) {
-
                while (memorystatus_update_vm_pressure(FALSE) == KERN_SUCCESS) {
                        continue;
                }
        }
-               
+
        if (pressure_level == NOTE_MEMORYSTATUS_PRESSURE_NORMAL) {
                memorystatus_manual_testing_on = FALSE;
-                               
-               vm_pressure_klist_lock();
-               vm_reset_active_list();
-               vm_pressure_klist_unlock();
-       } else {
-
-               vm_pressure_klist_lock();
-               vm_pressure_notification_without_levels(FALSE);
-               vm_pressure_klist_unlock();
        }
 
        return 0;
 }
 
-SYSCTL_PROC(_kern, OID_AUTO, memorypressure_manual_trigger, CTLTYPE_INT|CTLFLAG_WR|CTLFLAG_LOCKED|CTLFLAG_MASKED,
+SYSCTL_PROC(_kern, OID_AUTO, memorypressure_manual_trigger, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
     0, 0, &sysctl_memorypressure_manual_trigger, "I", "");
 
 
-extern int memorystatus_purge_on_warning;
-extern int memorystatus_purge_on_urgent;
-extern int memorystatus_purge_on_critical;
-
-SYSCTL_INT(_kern, OID_AUTO, memorystatus_purge_on_warning, CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_purge_on_warning, 0, "");
-SYSCTL_INT(_kern, OID_AUTO, memorystatus_purge_on_urgent, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_purge_on_urgent, 0, "");
-SYSCTL_INT(_kern, OID_AUTO, memorystatus_purge_on_critical, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_LOCKED, &memorystatus_purge_on_critical, 0, "");
+SYSCTL_INT(_kern, OID_AUTO, memorystatus_purge_on_warning, CTLFLAG_RW | CTLFLAG_LOCKED, &vm_pageout_state.memorystatus_purge_on_warning, 0, "");
+SYSCTL_INT(_kern, OID_AUTO, memorystatus_purge_on_urgent, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &vm_pageout_state.memorystatus_purge_on_urgent, 0, "");
+SYSCTL_INT(_kern, OID_AUTO, memorystatus_purge_on_critical, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &vm_pageout_state.memorystatus_purge_on_critical, 0, "");
 
+#if DEBUG || DEVELOPMENT
+SYSCTL_UINT(_kern, OID_AUTO, memorystatus_vm_pressure_events_enabled, CTLFLAG_RW | CTLFLAG_LOCKED, &vm_pressure_events_enabled, 0, "");
+#endif
 
 #endif /* VM_PRESSURE_EVENTS */
 
 /* Return both allocated and actual size, since there's a race between allocation and list compilation */
 static int
-memorystatus_get_priority_list(memorystatus_priority_entry_t **list_ptr, size_t *buffer_size, size_t *list_size, boolean_t size_only) 
+memorystatus_get_priority_list(memorystatus_priority_entry_t **list_ptr, size_t *buffer_size, size_t *list_size, boolean_t size_only)
 {
-       uint32_t list_count, i = 0;
+       uint32_t list_count, i = 0;
        memorystatus_priority_entry_t *list_entry;
        proc_t p;
 
-       list_count = memorystatus_list_count;
+       list_count = memorystatus_list_count;
        *list_size = sizeof(memorystatus_priority_entry_t) * list_count;
 
        /* Just a size check? */
        if (size_only) {
                return 0;
        }
-       
+
        /* Otherwise, validate the size of the buffer */
        if (*buffer_size < *list_size) {
                return EINVAL;
        }
 
-       *list_ptr = (memorystatus_priority_entry_t*)kalloc(*list_size);
-       if (!list_ptr) {
+       *list_ptr = (memorystatus_priority_entry_t*)kalloc(*list_size);
+       if (!*list_ptr) {
                return ENOMEM;
        }
 
@@ -4934,79 +8559,113 @@ memorystatus_get_priority_list(memorystatus_priority_entry_t **list_ptr, size_t
                list_entry->pid = p->p_pid;
                list_entry->priority = p->p_memstat_effectivepriority;
                list_entry->user_data = p->p_memstat_userdata;
-#if LEGACY_HIWATER
-
-               /*
-                * No need to consider P_MEMSTAT_MEMLIMIT_BACKGROUND anymore.
-                * Background limits are described via the inactive limit slots.
-                * So, here, the cached limit should always be valid.
-                */
 
                if (p->p_memstat_memlimit <= 0) {
-                        task_get_phys_footprint_limit(p->task, &list_entry->limit);
-                } else {
-                        list_entry->limit = p->p_memstat_memlimit;
-                }
-#else
-               task_get_phys_footprint_limit(p->task, &list_entry->limit);
-#endif
+                       task_get_phys_footprint_limit(p->task, &list_entry->limit);
+               } else {
+                       list_entry->limit = p->p_memstat_memlimit;
+               }
+
                list_entry->state = memorystatus_build_state(p);
                list_entry++;
 
                *list_size += sizeof(memorystatus_priority_entry_t);
-               
+
                p = memorystatus_get_next_proc_locked(&i, p, TRUE);
        }
-       
+
        proc_list_unlock();
-       
+
        MEMORYSTATUS_DEBUG(1, "memorystatus_get_priority_list: returning %lu for size\n", (unsigned long)*list_size);
-       
+
        return 0;
 }
 
 static int
-memorystatus_cmd_get_priority_list(user_addr_t buffer, size_t buffer_size, int32_t *retval) {
-       int error = EINVAL;
+memorystatus_get_priority_pid(pid_t pid, user_addr_t buffer, size_t buffer_size)
+{
+       int error = 0;
+       memorystatus_priority_entry_t mp_entry;
+
+       /* Validate inputs */
+       if ((pid == 0) || (buffer == USER_ADDR_NULL) || (buffer_size != sizeof(memorystatus_priority_entry_t))) {
+               return EINVAL;
+       }
+
+       proc_t p = proc_find(pid);
+       if (!p) {
+               return ESRCH;
+       }
+
+       memset(&mp_entry, 0, sizeof(memorystatus_priority_entry_t));
+
+       mp_entry.pid = p->p_pid;
+       mp_entry.priority = p->p_memstat_effectivepriority;
+       mp_entry.user_data = p->p_memstat_userdata;
+       if (p->p_memstat_memlimit <= 0) {
+               task_get_phys_footprint_limit(p->task, &mp_entry.limit);
+       } else {
+               mp_entry.limit = p->p_memstat_memlimit;
+       }
+       mp_entry.state = memorystatus_build_state(p);
+
+       proc_rele(p);
+
+       error = copyout(&mp_entry, buffer, buffer_size);
+
+       return error;
+}
+
+static int
+memorystatus_cmd_get_priority_list(pid_t pid, user_addr_t buffer, size_t buffer_size, int32_t *retval)
+{
+       int error = 0;
        boolean_t size_only;
-       memorystatus_priority_entry_t *list = NULL;
        size_t list_size;
-       
+
+       /*
+        * When a non-zero pid is provided, the 'list' has only one entry.
+        */
+
        size_only = ((buffer == USER_ADDR_NULL) ? TRUE: FALSE);
-               
-       error = memorystatus_get_priority_list(&list, &buffer_size, &list_size, size_only);
-       if (error) {
-               goto out;
-       }
 
-       if (!size_only) {
-               error = copyout(list, buffer, list_size);
+       if (pid != 0) {
+               list_size = sizeof(memorystatus_priority_entry_t) * 1;
+               if (!size_only) {
+                       error = memorystatus_get_priority_pid(pid, buffer, buffer_size);
+               }
+       } else {
+               memorystatus_priority_entry_t *list = NULL;
+               error = memorystatus_get_priority_list(&list, &buffer_size, &list_size, size_only);
+
+               if (error == 0) {
+                       if (!size_only) {
+                               error = copyout(list, buffer, list_size);
+                       }
+               }
+
+               if (list) {
+                       kfree(list, buffer_size);
+               }
        }
-       
+
        if (error == 0) {
                *retval = list_size;
        }
-out:
-
-       if (list) {
-               kfree(list, buffer_size);
-       }
 
        return error;
 }
 
-#if CONFIG_JETSAM
-
-static void 
+static void
 memorystatus_clear_errors(void)
 {
        proc_t p;
        unsigned int i = 0;
 
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_CLEAR_ERRORS) | DBG_FUNC_START, 0, 0, 0, 0, 0);
-    
+
        proc_list_lock();
-    
+
        p = memorystatus_get_first_proc_locked(&i, TRUE);
        while (p) {
                if (p->p_memstat_state & P_MEMSTAT_ERROR) {
@@ -5014,26 +8673,28 @@ memorystatus_clear_errors(void)
                }
                p = memorystatus_get_next_proc_locked(&i, p, TRUE);
        }
-       
+
        proc_list_unlock();
 
        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_CLEAR_ERRORS) | DBG_FUNC_END, 0, 0, 0, 0, 0);
 }
 
+#if CONFIG_JETSAM
 static void
-memorystatus_update_levels_locked(boolean_t critical_only) {
-
+memorystatus_update_levels_locked(boolean_t critical_only)
+{
        memorystatus_available_pages_critical = memorystatus_available_pages_critical_base;
 
        /*
         * If there's an entry in the first bucket, we have idle processes.
         */
+
        memstat_bucket_t *first_bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
        if (first_bucket->count) {
                memorystatus_available_pages_critical += memorystatus_available_pages_critical_idle_offset;
 
-               if (memorystatus_available_pages_critical  > memorystatus_available_pages_pressure ) {
-                       /* 
+               if (memorystatus_available_pages_critical > memorystatus_available_pages_pressure) {
+                       /*
                         * The critical threshold must never exceed the pressure threshold
                         */
                        memorystatus_available_pages_critical = memorystatus_available_pages_pressure;
@@ -5044,19 +8705,23 @@ memorystatus_update_levels_locked(boolean_t critical_only) {
        if (memorystatus_jetsam_policy & kPolicyDiagnoseActive) {
                memorystatus_available_pages_critical += memorystatus_jetsam_policy_offset_pages_diagnostic;
 
-               if (memorystatus_available_pages_critical > memorystatus_available_pages_pressure ) {
-                       /* 
+               if (memorystatus_available_pages_critical > memorystatus_available_pages_pressure) {
+                       /*
                         * The critical threshold must never exceed the pressure threshold
                         */
                        memorystatus_available_pages_critical = memorystatus_available_pages_pressure;
                }
        }
-#endif
-        
+#endif /* DEBUG || DEVELOPMENT */
+
+       if (memorystatus_jetsam_policy & kPolicyMoreFree) {
+               memorystatus_available_pages_critical += memorystatus_policy_more_free_offset_pages;
+       }
+
        if (critical_only) {
                return;
        }
-       
+
 #if VM_PRESSURE_EVENTS
        memorystatus_available_pages_pressure = (pressure_threshold_percentage / delta_percentage) * memorystatus_delta;
 #if DEBUG || DEVELOPMENT
@@ -5067,11 +8732,74 @@ memorystatus_update_levels_locked(boolean_t critical_only) {
 #endif
 }
 
+void
+memorystatus_fast_jetsam_override(boolean_t enable_override)
+{
+       /* If fast jetsam is not enabled, simply return */
+       if (!fast_jetsam_enabled) {
+               return;
+       }
+
+       if (enable_override) {
+               if ((memorystatus_jetsam_policy & kPolicyMoreFree) == kPolicyMoreFree) {
+                       return;
+               }
+               proc_list_lock();
+               memorystatus_jetsam_policy |= kPolicyMoreFree;
+               memorystatus_thread_pool_max();
+               memorystatus_update_levels_locked(TRUE);
+               proc_list_unlock();
+       } else {
+               if ((memorystatus_jetsam_policy & kPolicyMoreFree) == 0) {
+                       return;
+               }
+               proc_list_lock();
+               memorystatus_jetsam_policy &= ~kPolicyMoreFree;
+               memorystatus_thread_pool_default();
+               memorystatus_update_levels_locked(TRUE);
+               proc_list_unlock();
+       }
+}
+
+
+static int
+sysctl_kern_memorystatus_policy_more_free SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2, oidp)
+       int error = 0, more_free = 0;
+
+       /*
+        * TODO: Enable this privilege check?
+        *
+        * error = priv_check_cred(kauth_cred_get(), PRIV_VM_JETSAM, 0);
+        * if (error)
+        *      return (error);
+        */
+
+       error = sysctl_handle_int(oidp, &more_free, 0, req);
+       if (error || !req->newptr) {
+               return error;
+       }
+
+       if (more_free) {
+               memorystatus_fast_jetsam_override(true);
+       } else {
+               memorystatus_fast_jetsam_override(false);
+       }
+
+       return 0;
+}
+SYSCTL_PROC(_kern, OID_AUTO, memorystatus_policy_more_free, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+    0, 0, &sysctl_kern_memorystatus_policy_more_free, "I", "");
+
+#endif /* CONFIG_JETSAM */
+
 /*
  * Get the at_boot snapshot
  */
 static int
-memorystatus_get_at_boot_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only) {
+memorystatus_get_at_boot_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only)
+{
        size_t input_size = *snapshot_size;
 
        /*
@@ -5097,15 +8825,46 @@ memorystatus_get_at_boot_snapshot(memorystatus_jetsam_snapshot_t **snapshot, siz
        *snapshot = &memorystatus_at_boot_snapshot;
 
        MEMORYSTATUS_DEBUG(7, "memorystatus_get_at_boot_snapshot: returned inputsize (%ld), snapshot_size(%ld), listcount(%d)\n",
-                          (long)input_size, (long)*snapshot_size, 0);
+           (long)input_size, (long)*snapshot_size, 0);
+       return 0;
+}
+
+/*
+ * Get the previous fully populated snapshot
+ */
+static int
+memorystatus_get_jetsam_snapshot_copy(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only)
+{
+       size_t input_size = *snapshot_size;
+
+       if (memorystatus_jetsam_snapshot_copy_count > 0) {
+               *snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) + (sizeof(memorystatus_jetsam_snapshot_entry_t) * (memorystatus_jetsam_snapshot_copy_count));
+       } else {
+               *snapshot_size = 0;
+       }
+
+       if (size_only) {
+               return 0;
+       }
+
+       if (input_size < *snapshot_size) {
+               return EINVAL;
+       }
+
+       *snapshot = memorystatus_jetsam_snapshot_copy;
+
+       MEMORYSTATUS_DEBUG(7, "memorystatus_get_jetsam_snapshot_copy: returned inputsize (%ld), snapshot_size(%ld), listcount(%ld)\n",
+           (long)input_size, (long)*snapshot_size, (long)memorystatus_jetsam_snapshot_copy_count);
+
        return 0;
 }
 
 static int
-memorystatus_get_on_demand_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only) {
+memorystatus_get_on_demand_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only)
+{
        size_t input_size = *snapshot_size;
        uint32_t ods_list_count = memorystatus_list_count;
-       memorystatus_jetsam_snapshot_t *ods = NULL;     /* The on_demand snapshot buffer */
+       memorystatus_jetsam_snapshot_t *ods = NULL;     /* The on_demand snapshot buffer */
 
        *snapshot_size = sizeof(memorystatus_jetsam_snapshot_t) + (sizeof(memorystatus_jetsam_snapshot_entry_t) * (ods_list_count));
 
@@ -5128,7 +8887,7 @@ memorystatus_get_on_demand_snapshot(memorystatus_jetsam_snapshot_t **snapshot, s
         */
        ods = (memorystatus_jetsam_snapshot_t *)kalloc(*snapshot_size);
        if (!ods) {
-               return (ENOMEM);
+               return ENOMEM;
        }
 
        memset(ods, 0, *snapshot_size);
@@ -5146,13 +8905,14 @@ memorystatus_get_on_demand_snapshot(memorystatus_jetsam_snapshot_t **snapshot, s
        *snapshot = ods;
 
        MEMORYSTATUS_DEBUG(7, "memorystatus_get_on_demand_snapshot: returned inputsize (%ld), snapshot_size(%ld), listcount(%ld)\n",
-                                  (long)input_size, (long)*snapshot_size, (long)ods_list_count);
-       
+           (long)input_size, (long)*snapshot_size, (long)ods_list_count);
+
        return 0;
 }
 
 static int
-memorystatus_get_jetsam_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only) {
+memorystatus_get_jetsam_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size_t *snapshot_size, boolean_t size_only)
+{
        size_t input_size = *snapshot_size;
 
        if (memorystatus_jetsam_snapshot_count > 0) {
@@ -5172,14 +8932,15 @@ memorystatus_get_jetsam_snapshot(memorystatus_jetsam_snapshot_t **snapshot, size
        *snapshot = memorystatus_jetsam_snapshot;
 
        MEMORYSTATUS_DEBUG(7, "memorystatus_get_jetsam_snapshot: returned inputsize (%ld), snapshot_size(%ld), listcount(%ld)\n",
-                                  (long)input_size, (long)*snapshot_size, (long)memorystatus_jetsam_snapshot_count);
+           (long)input_size, (long)*snapshot_size, (long)memorystatus_jetsam_snapshot_count);
 
        return 0;
 }
 
 
 static int
-memorystatus_cmd_get_jetsam_snapshot(int32_t flags, user_addr_t buffer, size_t buffer_size, int32_t *retval) {
+memorystatus_cmd_get_jetsam_snapshot(int32_t flags, user_addr_t buffer, size_t buffer_size, int32_t *retval)
+{
        int error = EINVAL;
        boolean_t size_only;
        boolean_t is_default_snapshot = FALSE;
@@ -5194,17 +8955,16 @@ memorystatus_cmd_get_jetsam_snapshot(int32_t flags, user_addr_t buffer, size_t b
                is_default_snapshot = TRUE;
                error = memorystatus_get_jetsam_snapshot(&snapshot, &buffer_size, size_only);
        } else {
-               if (flags & ~(MEMORYSTATUS_SNAPSHOT_ON_DEMAND | MEMORYSTATUS_SNAPSHOT_AT_BOOT)) {
+               if (flags & ~(MEMORYSTATUS_SNAPSHOT_ON_DEMAND | MEMORYSTATUS_SNAPSHOT_AT_BOOT | MEMORYSTATUS_SNAPSHOT_COPY)) {
                        /*
                         * Unsupported bit set in flag.
                         */
                        return EINVAL;
                }
 
-               if ((flags & (MEMORYSTATUS_SNAPSHOT_ON_DEMAND | MEMORYSTATUS_SNAPSHOT_AT_BOOT)) ==
-                   (MEMORYSTATUS_SNAPSHOT_ON_DEMAND |  MEMORYSTATUS_SNAPSHOT_AT_BOOT)) {
+               if (flags & (flags - 0x1)) {
                        /*
-                        * Can't have both set at the same time.
+                        * Can't have multiple flags set at the same time.
                         */
                        return EINVAL;
                }
@@ -5216,10 +8976,11 @@ memorystatus_cmd_get_jetsam_snapshot(int32_t flags, user_addr_t buffer, size_t b
                         * an on_demand snapshot buffer, which is freed below.
                         */
                        error = memorystatus_get_on_demand_snapshot(&snapshot, &buffer_size, size_only);
-
                } else if (flags & MEMORYSTATUS_SNAPSHOT_AT_BOOT) {
                        is_at_boot_snapshot = TRUE;
                        error = memorystatus_get_at_boot_snapshot(&snapshot, &buffer_size, size_only);
+               } else if (flags & MEMORYSTATUS_SNAPSHOT_COPY) {
+                       error = memorystatus_get_jetsam_snapshot_copy(&snapshot, &buffer_size, size_only);
                } else {
                        /*
                         * Invalid flag setting.
@@ -5240,16 +9001,21 @@ memorystatus_cmd_get_jetsam_snapshot(int32_t flags, user_addr_t buffer, size_t b
         *      clearing the buffer means, free it.
         * If working with the at_boot snapshot
         *      there is nothing to clear or update.
+        * If working with a copy of the snapshot
+        *      there is nothing to clear or update.
         */
        if (!size_only) {
                if ((error = copyout(snapshot, buffer, buffer_size)) == 0) {
                        if (is_default_snapshot) {
                                /*
                                 * The jetsam snapshot is never freed, its count is simply reset.
+                                * However, we make a copy for any parties that might be interested
+                                * in the previous fully populated snapshot.
                                 */
-                               snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
-
                                proc_list_lock();
+                               memcpy(memorystatus_jetsam_snapshot_copy, memorystatus_jetsam_snapshot, memorystatus_jetsam_snapshot_size);
+                               memorystatus_jetsam_snapshot_copy_count = memorystatus_jetsam_snapshot_count;
+                               snapshot->entry_count = memorystatus_jetsam_snapshot_count = 0;
                                memorystatus_jetsam_snapshot_last_timestamp = 0;
                                proc_list_unlock();
                        }
@@ -5260,7 +9026,7 @@ memorystatus_cmd_get_jetsam_snapshot(int32_t flags, user_addr_t buffer, size_t b
                         * The on_demand snapshot is always freed,
                         * even if the copyout failed.
                         */
-                       if(snapshot) {
+                       if (snapshot) {
                                kfree(snapshot, buffer_size);
                        }
                }
@@ -5274,10 +9040,9 @@ out:
 }
 
 /*
- *     Routine:        memorystatus_cmd_grp_set_properties
- *     Purpose:        Update properties for a group of processes.
+ *      Routine:       memorystatus_cmd_grp_set_priorities
+ *     Purpose:        Update priorities for a group of processes.
  *
- *     Supported Properties:
  *     [priority]
  *             Move each process out of its effective priority
  *             band and into a new priority band.
@@ -5289,7 +9054,7 @@ out:
  *                             [17 | p55, p67, p19     ]
  *                             [12 | p103 p10          ]
  *                             [ 7 | p25               ]
- *                             [ 0 | p71, p82,         ]
+ *                             [ 0 | p71, p82,         ]
  *
  *             after   [ new band | pid]
  *                     [ xxx | p71, p82, p25, p103, p10, p55, p67, p19, p101]
@@ -5309,29 +9074,24 @@ out:
  */
 
 
-/* This internal structure can expand when we add support for more properties */
-typedef        struct memorystatus_internal_properties
-{
-       proc_t proc;
-       int32_t priority;  /* see memorytstatus_priority_entry_t : priority */
-} memorystatus_internal_properties_t;
-       
-
 static int
-memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval) {
-
-#pragma unused (flags)
-
+memorystatus_cmd_grp_set_priorities(user_addr_t buffer, size_t buffer_size)
+{
        /*
         * We only handle setting priority
         * per process
         */
 
        int error = 0;
-       memorystatus_priority_entry_t *entries = NULL;
+       memorystatus_properties_entry_v1_t *entries = NULL;
        uint32_t entry_count = 0;
 
        /* This will be the ordered proc list */
+       typedef struct memorystatus_internal_properties {
+               proc_t proc;
+               int32_t priority;
+       } memorystatus_internal_properties_t;
+
        memorystatus_internal_properties_t *table = NULL;
        size_t table_size = 0;
        uint32_t table_count = 0;
@@ -5340,37 +9100,47 @@ memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t bu
        uint32_t bucket_index = 0;
        boolean_t head_insert;
        int32_t new_priority;
-       
+
        proc_t p;
 
        /* Verify inputs */
-       if ((buffer == USER_ADDR_NULL) || (buffer_size == 0) || ((buffer_size % sizeof(memorystatus_priority_entry_t)) != 0)) {
+       if ((buffer == USER_ADDR_NULL) || (buffer_size == 0)) {
                error = EINVAL;
                goto out;
        }
 
-       entry_count = (buffer_size / sizeof(memorystatus_priority_entry_t));
-       if ((entries = (memorystatus_priority_entry_t *)kalloc(buffer_size)) == NULL) {
+       entry_count = (buffer_size / sizeof(memorystatus_properties_entry_v1_t));
+       if ((entries = (memorystatus_properties_entry_v1_t *)kalloc(buffer_size)) == NULL) {
                error = ENOMEM;
                goto out;
        }
 
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_GRP_SET_PROP) | DBG_FUNC_START, entry_count, 0, 0, 0, 0);
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_GRP_SET_PROP) | DBG_FUNC_START, MEMORYSTATUS_FLAGS_GRP_SET_PRIORITY, entry_count, 0, 0, 0);
 
        if ((error = copyin(buffer, entries, buffer_size)) != 0) {
                goto out;
        }
 
        /* Verify sanity of input priorities */
-       for (i=0; i < entry_count; i++) {
+       if (entries[0].version == MEMORYSTATUS_MPE_VERSION_1) {
+               if ((buffer_size % MEMORYSTATUS_MPE_VERSION_1_SIZE) != 0) {
+                       error = EINVAL;
+                       goto out;
+               }
+       } else {
+               error = EINVAL;
+               goto out;
+       }
+
+       for (i = 0; i < entry_count; i++) {
                if (entries[i].priority == -1) {
                        /* Use as shorthand for default priority */
                        entries[i].priority = JETSAM_PRIORITY_DEFAULT;
-               } else if (entries[i].priority == JETSAM_PRIORITY_IDLE_DEFERRED) {
-                       /* JETSAM_PRIORITY_IDLE_DEFERRED is reserved for internal use;
+               } else if ((entries[i].priority == system_procs_aging_band) || (entries[i].priority == applications_aging_band)) {
+                       /* Both the aging bands are reserved for internal use;
                         * if requested, adjust to JETSAM_PRIORITY_IDLE. */
                        entries[i].priority = JETSAM_PRIORITY_IDLE;
-               } else if (entries[i].priority == JETSAM_PRIORITY_IDLE_HEAD) {
+               } else if (entries[i].priority == JETSAM_PRIORITY_IDLE_HEAD) {
                        /* JETSAM_PRIORITY_IDLE_HEAD inserts at the head of the idle
                         * queue */
                        /* Deal with this later */
@@ -5382,7 +9152,7 @@ memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t bu
        }
 
        table_size = sizeof(memorystatus_internal_properties_t) * entry_count;
-       if ( (table = (memorystatus_internal_properties_t *)kalloc(table_size)) == NULL) {
+       if ((table = (memorystatus_internal_properties_t *)kalloc(table_size)) == NULL) {
                error = ENOMEM;
                goto out;
        }
@@ -5397,14 +9167,14 @@ memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t bu
         * to highest priority.
         */
 
-       bucket_index=0;
-       
+       bucket_index = 0;
+
        proc_list_lock();
 
        /* Create the ordered table */
-       p = memorystatus_get_first_proc_locked(&bucket_index, TRUE);    
+       p = memorystatus_get_first_proc_locked(&bucket_index, TRUE);
        while (p && (table_count < entry_count)) {
-               for (i=0; i < entry_count; i++ ) {
+               for (i = 0; i < entry_count; i++) {
                        if (p->p_pid == entries[i].pid) {
                                /* Build the table data  */
                                table[table_count].proc = p;
@@ -5415,9 +9185,9 @@ memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t bu
                }
                p = memorystatus_get_next_proc_locked(&bucket_index, p, TRUE);
        }
-       
+
        /* We now have ordered list of procs ready to move */
-       for (i=0; i < table_count; i++) {
+       for (i = 0; i < table_count; i++) {
                p = table[i].proc;
                assert(p != NULL);
 
@@ -5429,21 +9199,21 @@ memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t bu
                        new_priority = table[i].priority;
                        head_insert = false;
                }
-               
+
                /* Not allowed */
                if (p->p_memstat_state & P_MEMSTAT_INTERNAL) {
                        continue;
                }
 
                /*
-                * Take appropriate steps if moving proc out of the
-                * JETSAM_PRIORITY_IDLE_DEFERRED band.
+                * Take appropriate steps if moving proc out of
+                * either of the aging bands.
                 */
-               if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE_DEFERRED) {
+               if ((p->p_memstat_effectivepriority == system_procs_aging_band) || (p->p_memstat_effectivepriority == applications_aging_band)) {
                        memorystatus_invalidate_idle_demotion_locked(p, TRUE);
                }
 
-               memorystatus_update_priority_locked(p, new_priority, head_insert);
+               memorystatus_update_priority_locked(p, new_priority, head_insert, false);
        }
 
        proc_list_unlock();
@@ -5453,26 +9223,141 @@ memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t bu
         * then some pids were not found in a jetsam band.
         * harmless but interesting...
         */
-       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_GRP_SET_PROP) | DBG_FUNC_END, entry_count, table_count, 0, 0, 0);
-       
 out:
-       if (entries)
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_GRP_SET_PROP) | DBG_FUNC_END, MEMORYSTATUS_FLAGS_GRP_SET_PRIORITY, entry_count, table_count, 0, 0);
+
+       if (entries) {
                kfree(entries, buffer_size);
-       if (table)
+       }
+       if (table) {
                kfree(table, table_size);
+       }
+
+       return error;
+}
+
+static int
+memorystatus_cmd_grp_set_probabilities(user_addr_t buffer, size_t buffer_size)
+{
+       int error = 0;
+       memorystatus_properties_entry_v1_t *entries = NULL;
+       uint32_t entry_count = 0, i = 0;
+       memorystatus_internal_probabilities_t *tmp_table_new = NULL, *tmp_table_old = NULL;
+       size_t tmp_table_new_size = 0, tmp_table_old_size = 0;
+
+       /* Verify inputs */
+       if ((buffer == USER_ADDR_NULL) || (buffer_size == 0)) {
+               error = EINVAL;
+               goto out;
+       }
+
+       entry_count = (buffer_size / sizeof(memorystatus_properties_entry_v1_t));
+
+       if ((entries = (memorystatus_properties_entry_v1_t *) kalloc(buffer_size)) == NULL) {
+               error = ENOMEM;
+               goto out;
+       }
+
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_GRP_SET_PROP) | DBG_FUNC_START, MEMORYSTATUS_FLAGS_GRP_SET_PROBABILITY, entry_count, 0, 0, 0);
+
+       if ((error = copyin(buffer, entries, buffer_size)) != 0) {
+               goto out;
+       }
+
+       if (entries[0].version == MEMORYSTATUS_MPE_VERSION_1) {
+               if ((buffer_size % MEMORYSTATUS_MPE_VERSION_1_SIZE) != 0) {
+                       error = EINVAL;
+                       goto out;
+               }
+       } else {
+               error = EINVAL;
+               goto out;
+       }
+
+       /* Verify sanity of input priorities */
+       for (i = 0; i < entry_count; i++) {
+               /*
+                * 0 - low probability of use.
+                * 1 - high probability of use.
+                *
+                * Keeping this field an int (& not a bool) to allow
+                * us to experiment with different values/approaches
+                * later on.
+                */
+               if (entries[i].use_probability > 1) {
+                       error = EINVAL;
+                       goto out;
+               }
+       }
+
+       tmp_table_new_size = sizeof(memorystatus_internal_probabilities_t) * entry_count;
+
+       if ((tmp_table_new = (memorystatus_internal_probabilities_t *) kalloc(tmp_table_new_size)) == NULL) {
+               error = ENOMEM;
+               goto out;
+       }
+       memset(tmp_table_new, 0, tmp_table_new_size);
+
+       proc_list_lock();
+
+       if (memorystatus_global_probabilities_table) {
+               tmp_table_old = memorystatus_global_probabilities_table;
+               tmp_table_old_size = memorystatus_global_probabilities_size;
+       }
+
+       memorystatus_global_probabilities_table = tmp_table_new;
+       memorystatus_global_probabilities_size = tmp_table_new_size;
+       tmp_table_new = NULL;
 
-       return (error);
+       for (i = 0; i < entry_count; i++) {
+               /* Build the table data  */
+               strlcpy(memorystatus_global_probabilities_table[i].proc_name, entries[i].proc_name, MAXCOMLEN + 1);
+               memorystatus_global_probabilities_table[i].use_probability = entries[i].use_probability;
+       }
+
+       proc_list_unlock();
+
+out:
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_GRP_SET_PROP) | DBG_FUNC_END, MEMORYSTATUS_FLAGS_GRP_SET_PROBABILITY, entry_count, tmp_table_new_size, 0, 0);
+
+       if (entries) {
+               kfree(entries, buffer_size);
+               entries = NULL;
+       }
+
+       if (tmp_table_old) {
+               kfree(tmp_table_old, tmp_table_old_size);
+               tmp_table_old = NULL;
+       }
+
+       return error;
 }
 
+static int
+memorystatus_cmd_grp_set_properties(int32_t flags, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval)
+{
+       int error = 0;
+
+       if ((flags & MEMORYSTATUS_FLAGS_GRP_SET_PRIORITY) == MEMORYSTATUS_FLAGS_GRP_SET_PRIORITY) {
+               error = memorystatus_cmd_grp_set_priorities(buffer, buffer_size);
+       } else if ((flags & MEMORYSTATUS_FLAGS_GRP_SET_PROBABILITY) == MEMORYSTATUS_FLAGS_GRP_SET_PROBABILITY) {
+               error = memorystatus_cmd_grp_set_probabilities(buffer, buffer_size);
+       } else {
+               error = EINVAL;
+       }
+
+       return error;
+}
 
 /*
  * This routine is used to update a process's jetsam priority position and stored user_data.
  * It is not used for the setting of memory limits, which is why the last 6 args to the
  * memorystatus_update() call are 0 or FALSE.
  */
-       
+
 static int
-memorystatus_cmd_set_priority_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval) {
+memorystatus_cmd_set_priority_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval)
+{
        int error = 0;
        memorystatus_priority_properties_t mpp_entry;
 
@@ -5480,31 +9365,32 @@ memorystatus_cmd_set_priority_properties(pid_t pid, user_addr_t buffer, size_t b
        if ((pid == 0) || (buffer == USER_ADDR_NULL) || (buffer_size != sizeof(memorystatus_priority_properties_t))) {
                return EINVAL;
        }
-       
+
        error = copyin(buffer, &mpp_entry, buffer_size);
 
        if (error == 0) {
                proc_t p;
-                
+
                p = proc_find(pid);
                if (!p) {
                        return ESRCH;
                }
-               
+
                if (p->p_memstat_state & P_MEMSTAT_INTERNAL) {
                        proc_rele(p);
                        return EPERM;
                }
-       
-               error = memorystatus_update(p, mpp_entry.priority, mpp_entry.user_data, FALSE, FALSE, 0, 0, FALSE, FALSE, FALSE);
+
+               error = memorystatus_update(p, mpp_entry.priority, mpp_entry.user_data, FALSE, FALSE, 0, 0, FALSE, FALSE);
                proc_rele(p);
        }
-       
-       return(error);
+
+       return error;
 }
 
 static int
-memorystatus_cmd_set_memlimit_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval) {
+memorystatus_cmd_set_memlimit_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval)
+{
        int error = 0;
        memorystatus_memlimit_properties_t mmp_entry;
 
@@ -5519,7 +9405,7 @@ memorystatus_cmd_set_memlimit_properties(pid_t pid, user_addr_t buffer, size_t b
                error = memorystatus_set_memlimit_properties(pid, &mmp_entry);
        }
 
-       return(error);
+       return error;
 }
 
 /*
@@ -5530,7 +9416,8 @@ memorystatus_cmd_set_memlimit_properties(pid_t pid, user_addr_t buffer, size_t b
  * to the task's ledgers via task_set_phys_footprint_limit().
  */
 static int
-memorystatus_cmd_get_memlimit_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval) {
+memorystatus_cmd_get_memlimit_properties(pid_t pid, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval)
+{
        int error = 0;
        memorystatus_memlimit_properties_t mmp_entry;
 
@@ -5539,7 +9426,7 @@ memorystatus_cmd_get_memlimit_properties(pid_t pid, user_addr_t buffer, size_t b
                return EINVAL;
        }
 
-       memset (&mmp_entry, 0, sizeof(memorystatus_memlimit_properties_t));
+       memset(&mmp_entry, 0, sizeof(memorystatus_memlimit_properties_t));
 
        proc_t p = proc_find(pid);
        if (!p) {
@@ -5551,7 +9438,7 @@ memorystatus_cmd_get_memlimit_properties(pid_t pid, user_addr_t buffer, size_t b
         * No locks taken since we hold a reference to the proc.
         */
 
-       if (p->p_memstat_memlimit_active > 0 ) {
+       if (p->p_memstat_memlimit_active > 0) {
                mmp_entry.memlimit_active = p->p_memstat_memlimit_active;
        } else {
                task_convert_phys_footprint_limit(-1, &mmp_entry.memlimit_active);
@@ -5576,28 +9463,86 @@ memorystatus_cmd_get_memlimit_properties(pid_t pid, user_addr_t buffer, size_t b
 
        error = copyout(&mmp_entry, buffer, buffer_size);
 
-       return(error);
+       return error;
+}
+
+
+/*
+ * SPI for kbd - pr24956468
+ * This is a very simple snapshot that calculates how much a
+ * process's phys_footprint exceeds a specific memory limit.
+ * Only the inactive memory limit is supported for now.
+ * The delta is returned as bytes in excess or zero.
+ */
+static int
+memorystatus_cmd_get_memlimit_excess_np(pid_t pid, uint32_t flags, user_addr_t buffer, size_t buffer_size, __unused int32_t *retval)
+{
+       int error = 0;
+       uint64_t footprint_in_bytes = 0;
+       uint64_t delta_in_bytes = 0;
+       int32_t  memlimit_mb = 0;
+       uint64_t memlimit_bytes = 0;
+
+       /* Validate inputs */
+       if ((pid == 0) || (buffer == USER_ADDR_NULL) || (buffer_size != sizeof(uint64_t)) || (flags != 0)) {
+               return EINVAL;
+       }
+
+       proc_t p = proc_find(pid);
+       if (!p) {
+               return ESRCH;
+       }
+
+       /*
+        * Get the inactive limit.
+        * No locks taken since we hold a reference to the proc.
+        */
+
+       if (p->p_memstat_memlimit_inactive <= 0) {
+               task_convert_phys_footprint_limit(-1, &memlimit_mb);
+       } else {
+               memlimit_mb = p->p_memstat_memlimit_inactive;
+       }
+
+       footprint_in_bytes = get_task_phys_footprint(p->task);
+
+       proc_rele(p);
+
+       memlimit_bytes = memlimit_mb * 1024 * 1024;     /* MB to bytes */
+
+       /*
+        * Computed delta always returns >= 0 bytes
+        */
+       if (footprint_in_bytes > memlimit_bytes) {
+               delta_in_bytes = footprint_in_bytes - memlimit_bytes;
+       }
+
+       error = copyout(&delta_in_bytes, buffer, sizeof(delta_in_bytes));
+
+       return error;
 }
 
 
 static int
-memorystatus_cmd_get_pressure_status(int32_t *retval) {        
+memorystatus_cmd_get_pressure_status(int32_t *retval)
+{
        int error;
-       
+
        /* Need privilege for check */
        error = priv_check_cred(kauth_cred_get(), PRIV_VM_PRESSURE, 0);
        if (error) {
-               return (error);
+               return error;
        }
-       
+
        /* Inherently racy, so it's not worth taking a lock here */
        *retval = (kVMPressureNormal != memorystatus_vm_pressure_level) ? 1 : 0;
-       
+
        return error;
 }
 
 int
-memorystatus_get_pressure_status_kdp() {
+memorystatus_get_pressure_status_kdp()
+{
        return (kVMPressureNormal != memorystatus_vm_pressure_level) ? 1 : 0;
 }
 
@@ -5618,8 +9563,10 @@ memorystatus_get_pressure_status_kdp() {
  *      - so mapping is (active/fatal, inactive/fatal)
  */
 
+#if CONFIG_JETSAM
 static int
-memorystatus_cmd_set_jetsam_memory_limit(pid_t pid, int32_t high_water_mark, __unused int32_t *retval, boolean_t is_fatal_limit) {
+memorystatus_cmd_set_jetsam_memory_limit(pid_t pid, int32_t high_water_mark, __unused int32_t *retval, boolean_t is_fatal_limit)
+{
        int error = 0;
        memorystatus_memlimit_properties_t entry;
 
@@ -5634,19 +9581,20 @@ memorystatus_cmd_set_jetsam_memory_limit(pid_t pid, int32_t high_water_mark, __u
        }
 
        error = memorystatus_set_memlimit_properties(pid, &entry);
-       return (error);
+       return error;
 }
+#endif /* CONFIG_JETSAM */
 
 static int
-memorystatus_set_memlimit_properties(pid_t pid, memorystatus_memlimit_properties_t *entry) {
-
+memorystatus_set_memlimit_properties(pid_t pid, memorystatus_memlimit_properties_t *entry)
+{
        int32_t  memlimit_active;
        boolean_t memlimit_active_is_fatal;
        int32_t  memlimit_inactive;
        boolean_t memlimit_inactive_is_fatal;
        uint32_t valid_attrs = 0;
        int       error = 0;
-        
+
        proc_t p = proc_find(pid);
        if (!p) {
                return ESRCH;
@@ -5727,31 +9675,30 @@ memorystatus_set_memlimit_properties(pid_t pid, memorystatus_memlimit_properties
         */
 
        if (memorystatus_highwater_enabled) {
-               boolean_t trigger_exception;
-               /*
-                * No need to consider P_MEMSTAT_MEMLIMIT_BACKGROUND anymore.
-                * Background limits are described via the inactive limit slots.
-                */
+               boolean_t is_fatal;
+               boolean_t use_active;
 
                if (proc_jetsam_state_is_active_locked(p) == TRUE) {
-                       CACHE_ACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                       CACHE_ACTIVE_LIMITS_LOCKED(p, is_fatal);
+                       use_active = TRUE;
                } else {
-                       CACHE_INACTIVE_LIMITS_LOCKED(p, trigger_exception);
+                       CACHE_INACTIVE_LIMITS_LOCKED(p, is_fatal);
+                       use_active = FALSE;
                }
 
                /* Enforce the limit by writing to the ledgers */
-               assert(trigger_exception == TRUE);
-               error = (task_set_phys_footprint_limit_internal(p->task, ((p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1), NULL, trigger_exception) == 0) ? 0 : EINVAL;
+               error = (task_set_phys_footprint_limit_internal(p->task, ((p->p_memstat_memlimit > 0) ? p->p_memstat_memlimit : -1), NULL, use_active, is_fatal) == 0) ? 0 : EINVAL;
 
                MEMORYSTATUS_DEBUG(3, "memorystatus_set_memlimit_properties: new limit on pid %d (%dMB %s) current priority (%d) dirty_state?=0x%x %s\n",
-                                  p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
-                                  (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), p->p_memstat_effectivepriority, p->p_memstat_dirty,
-                                  (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
+                   p->p_pid, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1),
+                   (p->p_memstat_state & P_MEMSTAT_FATAL_MEMLIMIT ? "F " : "NF"), p->p_memstat_effectivepriority, p->p_memstat_dirty,
+                   (p->p_memstat_dirty ? ((p->p_memstat_dirty & P_DIRTY) ? "isdirty" : "isclean") : ""));
+               DTRACE_MEMORYSTATUS2(memorystatus_set_memlimit, proc_t, p, int32_t, (p->p_memstat_memlimit > 0 ? p->p_memstat_memlimit : -1));
        }
 
        proc_list_unlock();
        proc_rele(p);
-       
+
        return error;
 }
 
@@ -5772,86 +9719,165 @@ proc_get_memstat_priority(proc_t p, boolean_t effective_priority)
        return 0;
 }
 
-/*
- * Description:
- *     Evaluates active vs. inactive process state.
- *     Processes that opt into dirty tracking are evaluated
- *     based on clean vs dirty state.
- *     dirty ==> active
- *     clean ==> inactive
- *
- *     Process that do not opt into dirty tracking are
- *     evalulated based on priority level.
- *     Foreground or above ==> active
- *     Below Foreground    ==> inactive
- *
- *     Return: TRUE if active
- *             False if inactive
- */
+static int
+memorystatus_get_process_is_managed(pid_t pid, int *is_managed)
+{
+       proc_t p = NULL;
 
-static boolean_t
-proc_jetsam_state_is_active_locked(proc_t p) {
+       /* Validate inputs */
+       if (pid == 0) {
+               return EINVAL;
+       }
 
-       if (p->p_memstat_dirty & P_DIRTY_TRACK) {
-               /*
-                * process has opted into dirty tracking
-                * active state is based on dirty vs. clean
-                */
-               if (p->p_memstat_dirty & P_DIRTY_IS_DIRTY) {
-                       /*
-                        * process is dirty
-                        * implies active state
-                        */
-                       return TRUE;
-               } else {
-                       /*
-                        * process is clean
-                        * implies inactive state
-                        */
-                       return FALSE;
-               }
-       } else if (p->p_memstat_effectivepriority >= JETSAM_PRIORITY_FOREGROUND) {
-               /*
-                * process is Foreground or higher
-                * implies active state
-                */
-               return TRUE;
+       p = proc_find(pid);
+       if (!p) {
+               return ESRCH;
+       }
+
+       proc_list_lock();
+       *is_managed = ((p->p_memstat_state & P_MEMSTAT_MANAGED) ? 1 : 0);
+       proc_rele_locked(p);
+       proc_list_unlock();
+
+       return 0;
+}
+
+static int
+memorystatus_set_process_is_managed(pid_t pid, boolean_t set_managed)
+{
+       proc_t p = NULL;
+
+       /* Validate inputs */
+       if (pid == 0) {
+               return EINVAL;
+       }
+
+       p = proc_find(pid);
+       if (!p) {
+               return ESRCH;
+       }
+
+       proc_list_lock();
+       if (set_managed == TRUE) {
+               p->p_memstat_state |= P_MEMSTAT_MANAGED;
+       } else {
+               p->p_memstat_state &= ~P_MEMSTAT_MANAGED;
+       }
+       proc_rele_locked(p);
+       proc_list_unlock();
+
+       return 0;
+}
+
+static int
+memorystatus_get_process_is_freezable(pid_t pid, int *is_freezable)
+{
+       proc_t p = PROC_NULL;
+
+       if (pid == 0) {
+               return EINVAL;
+       }
+
+       p = proc_find(pid);
+       if (!p) {
+               return ESRCH;
+       }
+
+       /*
+        * Only allow this on the current proc for now.
+        * We can check for privileges and allow targeting another process in the future.
+        */
+       if (p != current_proc()) {
+               proc_rele(p);
+               return EPERM;
+       }
+
+       proc_list_lock();
+       *is_freezable = ((p->p_memstat_state & P_MEMSTAT_FREEZE_DISABLED) ? 0 : 1);
+       proc_rele_locked(p);
+       proc_list_unlock();
+
+       return 0;
+}
+
+static int
+memorystatus_set_process_is_freezable(pid_t pid, boolean_t is_freezable)
+{
+       proc_t p = PROC_NULL;
+
+       if (pid == 0) {
+               return EINVAL;
+       }
+
+       p = proc_find(pid);
+       if (!p) {
+               return ESRCH;
+       }
+
+       /*
+        * Only allow this on the current proc for now.
+        * We can check for privileges and allow targeting another process in the future.
+        */
+       if (p != current_proc()) {
+               proc_rele(p);
+               return EPERM;
+       }
+
+       proc_list_lock();
+       if (is_freezable == FALSE) {
+               /* Freeze preference set to FALSE. Set the P_MEMSTAT_FREEZE_DISABLED bit. */
+               p->p_memstat_state |= P_MEMSTAT_FREEZE_DISABLED;
+               printf("memorystatus_set_process_is_freezable: disabling freeze for pid %d [%s]\n",
+                   p->p_pid, (*p->p_name ? p->p_name : "unknown"));
        } else {
-               /*
-                * process found below Foreground
-                * implies inactive state
-                */
-               return FALSE;
+               p->p_memstat_state &= ~P_MEMSTAT_FREEZE_DISABLED;
+               printf("memorystatus_set_process_is_freezable: enabling freeze for pid %d [%s]\n",
+                   p->p_pid, (*p->p_name ? p->p_name : "unknown"));
        }
-}
+       proc_rele_locked(p);
+       proc_list_unlock();
 
-#endif /* CONFIG_JETSAM */
+       return 0;
+}
 
 int
-memorystatus_control(struct proc *p __unused, struct memorystatus_control_args *args, int *ret) {
+memorystatus_control(struct proc *p __unused, struct memorystatus_control_args *args, int *ret)
+{
        int error = EINVAL;
+       boolean_t skip_auth_check = FALSE;
+       os_reason_t jetsam_reason = OS_REASON_NULL;
 
 #if !CONFIG_JETSAM
        #pragma unused(ret)
+       #pragma unused(jetsam_reason)
 #endif
 
-       /* Root only for now */
-       if (!kauth_cred_issuser(kauth_cred_get())) {
+       /* We don't need entitlements if we're setting/ querying the freeze preference for a process. Skip the check below. */
+       if (args->command == MEMORYSTATUS_CMD_SET_PROCESS_IS_FREEZABLE || args->command == MEMORYSTATUS_CMD_GET_PROCESS_IS_FREEZABLE) {
+               skip_auth_check = TRUE;
+       }
+
+       /* Need to be root or have entitlement. */
+       if (!kauth_cred_issuser(kauth_cred_get()) && !IOTaskHasEntitlement(current_task(), MEMORYSTATUS_ENTITLEMENT) && !skip_auth_check) {
                error = EPERM;
                goto out;
        }
-       
-       /* Sanity check */
-       if (args->buffersize > MEMORYSTATUS_BUFFERSIZE_MAX) {
-               error = EINVAL;
-               goto out;
+
+       /*
+        * Sanity check.
+        * Do not enforce it for snapshots.
+        */
+       if (args->command != MEMORYSTATUS_CMD_GET_JETSAM_SNAPSHOT) {
+               if (args->buffersize > MEMORYSTATUS_BUFFERSIZE_MAX) {
+                       error = EINVAL;
+                       goto out;
+               }
        }
 
        switch (args->command) {
        case MEMORYSTATUS_CMD_GET_PRIORITY_LIST:
-               error = memorystatus_cmd_get_priority_list(args->buffer, args->buffersize, ret);
+               error = memorystatus_cmd_get_priority_list(args->pid, args->buffer, args->buffersize, ret);
                break;
-#if CONFIG_JETSAM
        case MEMORYSTATUS_CMD_SET_PRIORITY_PROPERTIES:
                error = memorystatus_cmd_set_priority_properties(args->pid, args->buffer, args->buffersize, ret);
                break;
@@ -5861,15 +9887,19 @@ memorystatus_control(struct proc *p __unused, struct memorystatus_control_args *
        case MEMORYSTATUS_CMD_GET_MEMLIMIT_PROPERTIES:
                error = memorystatus_cmd_get_memlimit_properties(args->pid, args->buffer, args->buffersize, ret);
                break;
+       case MEMORYSTATUS_CMD_GET_MEMLIMIT_EXCESS:
+               error = memorystatus_cmd_get_memlimit_excess_np(args->pid, args->flags, args->buffer, args->buffersize, ret);
+               break;
        case MEMORYSTATUS_CMD_GRP_SET_PROPERTIES:
                error = memorystatus_cmd_grp_set_properties((int32_t)args->flags, args->buffer, args->buffersize, ret);
-               break;          
+               break;
        case MEMORYSTATUS_CMD_GET_JETSAM_SNAPSHOT:
                error = memorystatus_cmd_get_jetsam_snapshot((int32_t)args->flags, args->buffer, args->buffersize, ret);
                break;
        case MEMORYSTATUS_CMD_GET_PRESSURE_STATUS:
                error = memorystatus_cmd_get_pressure_status(ret);
                break;
+#if CONFIG_JETSAM
        case MEMORYSTATUS_CMD_SET_JETSAM_HIGH_WATER_MARK:
                /*
                 * This call does not distinguish between active and inactive limits.
@@ -5886,23 +9916,80 @@ memorystatus_control(struct proc *p __unused, struct memorystatus_control_args *
                 */
                error = memorystatus_cmd_set_jetsam_memory_limit(args->pid, (int32_t)args->flags, ret, TRUE);
                break;
-       /* Test commands */
+#endif /* CONFIG_JETSAM */
+               /* Test commands */
 #if DEVELOPMENT || DEBUG
        case MEMORYSTATUS_CMD_TEST_JETSAM:
-               error = memorystatus_kill_process_sync(args->pid, kMemorystatusKilled) ? 0 : EINVAL;
+               jetsam_reason = os_reason_create(OS_REASON_JETSAM, JETSAM_REASON_GENERIC);
+               if (jetsam_reason == OS_REASON_NULL) {
+                       printf("memorystatus_control: failed to allocate jetsam reason\n");
+               }
+
+               error = memorystatus_kill_process_sync(args->pid, kMemorystatusKilled, jetsam_reason) ? 0 : EINVAL;
                break;
        case MEMORYSTATUS_CMD_TEST_JETSAM_SORT:
                error = memorystatus_cmd_test_jetsam_sort(args->pid, (int32_t)args->flags);
                break;
+#if CONFIG_JETSAM
        case MEMORYSTATUS_CMD_SET_JETSAM_PANIC_BITS:
                error = memorystatus_cmd_set_panic_bits(args->buffer, args->buffersize);
                break;
-#endif /* DEVELOPMENT || DEBUG */
 #endif /* CONFIG_JETSAM */
+#else /* DEVELOPMENT || DEBUG */
+       #pragma unused(jetsam_reason)
+#endif /* DEVELOPMENT || DEBUG */
+       case MEMORYSTATUS_CMD_AGGRESSIVE_JETSAM_LENIENT_MODE_ENABLE:
+               if (memorystatus_aggressive_jetsam_lenient_allowed == FALSE) {
+#if DEVELOPMENT || DEBUG
+                       printf("Enabling Lenient Mode\n");
+#endif /* DEVELOPMENT || DEBUG */
+
+                       memorystatus_aggressive_jetsam_lenient_allowed = TRUE;
+                       memorystatus_aggressive_jetsam_lenient = TRUE;
+                       error = 0;
+               }
+               break;
+       case MEMORYSTATUS_CMD_AGGRESSIVE_JETSAM_LENIENT_MODE_DISABLE:
+#if DEVELOPMENT || DEBUG
+               printf("Disabling Lenient mode\n");
+#endif /* DEVELOPMENT || DEBUG */
+               memorystatus_aggressive_jetsam_lenient_allowed = FALSE;
+               memorystatus_aggressive_jetsam_lenient = FALSE;
+               error = 0;
+               break;
        case MEMORYSTATUS_CMD_PRIVILEGED_LISTENER_ENABLE:
        case MEMORYSTATUS_CMD_PRIVILEGED_LISTENER_DISABLE:
                error = memorystatus_low_mem_privileged_listener(args->command);
                break;
+
+       case MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_ENABLE:
+       case MEMORYSTATUS_CMD_ELEVATED_INACTIVEJETSAMPRIORITY_DISABLE:
+               error = memorystatus_update_inactive_jetsam_priority_band(args->pid, args->command, JETSAM_PRIORITY_ELEVATED_INACTIVE, args->flags ? TRUE : FALSE);
+               break;
+       case MEMORYSTATUS_CMD_SET_PROCESS_IS_MANAGED:
+               error = memorystatus_set_process_is_managed(args->pid, args->flags);
+               break;
+
+       case MEMORYSTATUS_CMD_GET_PROCESS_IS_MANAGED:
+               error = memorystatus_get_process_is_managed(args->pid, ret);
+               break;
+
+       case MEMORYSTATUS_CMD_SET_PROCESS_IS_FREEZABLE:
+               error = memorystatus_set_process_is_freezable(args->pid, args->flags ? TRUE : FALSE);
+               break;
+
+       case MEMORYSTATUS_CMD_GET_PROCESS_IS_FREEZABLE:
+               error = memorystatus_get_process_is_freezable(args->pid, ret);
+               break;
+
+#if CONFIG_FREEZE
+#if DEVELOPMENT || DEBUG
+       case MEMORYSTATUS_CMD_FREEZER_CONTROL:
+               error = memorystatus_freezer_control(args->flags, args->buffer, args->buffersize, ret);
+               break;
+#endif /* DEVELOPMENT || DEBUG */
+#endif /* CONFIG_FREEZE */
+
        default:
                break;
        }
@@ -5913,10 +10000,17 @@ out:
 
 
 static int
-filt_memorystatusattach(struct knote *kn)
-{      
+filt_memorystatusattach(struct knote *kn, __unused struct kevent_internal_s *kev)
+{
+       int error;
+
        kn->kn_flags |= EV_CLEAR;
-       return memorystatus_knote_register(kn);
+       error = memorystatus_knote_register(kn);
+       if (error) {
+               kn->kn_flags = EV_ERROR;
+               kn->kn_data = error;
+       }
+       return 0;
 }
 
 static void
@@ -5941,7 +10035,6 @@ filt_memorystatus(struct knote *kn __unused, long hint)
                                        kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_WARN;
                                }
                        } else if (memorystatus_vm_pressure_level == kVMPressureCritical) {
-
                                if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_CRITICAL) {
                                        kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_CRITICAL;
                                }
@@ -5952,51 +10045,197 @@ filt_memorystatus(struct knote *kn __unused, long hint)
                                kn->kn_fflags = NOTE_MEMORYSTATUS_LOW_SWAP;
                        }
                        break;
+
+               case kMemorystatusProcLimitWarn:
+                       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) {
+                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_WARN;
+                       }
+                       break;
+
+               case kMemorystatusProcLimitCritical:
+                       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) {
+                               kn->kn_fflags = NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL;
+                       }
+                       break;
+
                default:
                        break;
                }
        }
-       
-       return (kn->kn_fflags != 0);
+
+#if 0
+       if (kn->kn_fflags != 0) {
+               proc_t knote_proc = knote_get_kq(kn)->kq_p;
+               pid_t knote_pid = knote_proc->p_pid;
+
+               printf("filt_memorystatus: sending kn 0x%lx (event 0x%x) for pid (%d)\n",
+                   (unsigned long)kn, kn->kn_fflags, knote_pid);
+       }
+#endif
+
+       return kn->kn_fflags != 0;
+}
+
+static int
+filt_memorystatustouch(struct knote *kn, struct kevent_internal_s *kev)
+{
+       int res;
+       int prev_kn_sfflags = 0;
+
+       memorystatus_klist_lock();
+
+       /*
+        * copy in new kevent settings
+        * (saving the "desired" data and fflags).
+        */
+
+       prev_kn_sfflags = kn->kn_sfflags;
+       kn->kn_sfflags = (kev->fflags & EVFILT_MEMORYSTATUS_ALL_MASK);
+
+#if !CONFIG_EMBEDDED
+       /*
+        * Only on desktop do we restrict notifications to
+        * one per active/inactive state (soft limits only).
+        */
+       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) {
+               /*
+                * Is there previous state to preserve?
+                */
+               if (prev_kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) {
+                       /*
+                        * This knote was previously interested in proc_limit_warn,
+                        * so yes, preserve previous state.
+                        */
+                       if (prev_kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_ACTIVE) {
+                               kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_ACTIVE;
+                       }
+                       if (prev_kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_INACTIVE) {
+                               kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_INACTIVE;
+                       }
+               } else {
+                       /*
+                        * This knote was not previously interested in proc_limit_warn,
+                        * but it is now.  Set both states.
+                        */
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_ACTIVE;
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_INACTIVE;
+               }
+       }
+
+       if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) {
+               /*
+                * Is there previous state to preserve?
+                */
+               if (prev_kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) {
+                       /*
+                        * This knote was previously interested in proc_limit_critical,
+                        * so yes, preserve previous state.
+                        */
+                       if (prev_kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_ACTIVE) {
+                               kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_ACTIVE;
+                       }
+                       if (prev_kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_INACTIVE) {
+                               kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_INACTIVE;
+                       }
+               } else {
+                       /*
+                        * This knote was not previously interested in proc_limit_critical,
+                        * but it is now.  Set both states.
+                        */
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_ACTIVE;
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_INACTIVE;
+               }
+       }
+#endif /* !CONFIG_EMBEDDED */
+
+       /*
+        * reset the output flags based on a
+        * combination of the old events and
+        * the new desired event list.
+        */
+       //kn->kn_fflags &= kn->kn_sfflags;
+
+       res = (kn->kn_fflags != 0);
+
+       memorystatus_klist_unlock();
+
+       return res;
+}
+
+static int
+filt_memorystatusprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+{
+#pragma unused(data)
+       int res;
+
+       memorystatus_klist_lock();
+       res = (kn->kn_fflags != 0);
+       if (res) {
+               *kev = kn->kn_kevent;
+               kn->kn_flags |= EV_CLEAR; /* automatic */
+               kn->kn_fflags = 0;
+               kn->kn_data = 0;
+       }
+       memorystatus_klist_unlock();
+
+       return res;
 }
 
 static void
-memorystatus_klist_lock(void) {
+memorystatus_klist_lock(void)
+{
        lck_mtx_lock(&memorystatus_klist_mutex);
 }
 
 static void
-memorystatus_klist_unlock(void) {
+memorystatus_klist_unlock(void)
+{
        lck_mtx_unlock(&memorystatus_klist_mutex);
 }
 
-void 
-memorystatus_kevent_init(lck_grp_t *grp, lck_attr_t *attr) {
+void
+memorystatus_kevent_init(lck_grp_t *grp, lck_attr_t *attr)
+{
        lck_mtx_init(&memorystatus_klist_mutex, grp, attr);
        klist_init(&memorystatus_klist);
 }
 
 int
-memorystatus_knote_register(struct knote *kn) {
+memorystatus_knote_register(struct knote *kn)
+{
        int error = 0;
-       
+
        memorystatus_klist_lock();
-       
-       if (kn->kn_sfflags & (NOTE_MEMORYSTATUS_PRESSURE_NORMAL | NOTE_MEMORYSTATUS_PRESSURE_WARN | NOTE_MEMORYSTATUS_PRESSURE_CRITICAL | NOTE_MEMORYSTATUS_LOW_SWAP)) {
 
-               KNOTE_ATTACH(&memorystatus_klist, kn);
+       /*
+        * Support only userspace visible flags.
+        */
+       if ((kn->kn_sfflags & EVFILT_MEMORYSTATUS_ALL_MASK) == (unsigned int) kn->kn_sfflags) {
+#if !CONFIG_EMBEDDED
+               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_WARN) {
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_ACTIVE;
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_WARN_INACTIVE;
+               }
+
+               if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL) {
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_ACTIVE;
+                       kn->kn_sfflags |= NOTE_MEMORYSTATUS_PROC_LIMIT_CRITICAL_INACTIVE;
+               }
+#endif /* !CONFIG_EMBEDDED */
 
-       } else {          
+               KNOTE_ATTACH(&memorystatus_klist, kn);
+       } else {
                error = ENOTSUP;
        }
-       
+
        memorystatus_klist_unlock();
-       
+
        return error;
 }
 
 void
-memorystatus_knote_unregister(struct knote *kn __unused) {     
+memorystatus_knote_unregister(struct knote *kn __unused)
+{
        memorystatus_klist_lock();
        KNOTE_DETACH(&memorystatus_klist, kn);
        memorystatus_klist_unlock();
@@ -6006,7 +10245,8 @@ memorystatus_knote_unregister(struct knote *kn __unused) {
 #if 0
 #if CONFIG_JETSAM && VM_PRESSURE_EVENTS
 static boolean_t
-memorystatus_issue_pressure_kevent(boolean_t pressured) {
+memorystatus_issue_pressure_kevent(boolean_t pressured)
+{
        memorystatus_klist_lock();
        KNOTE(&memorystatus_klist, pressured ? kMemorystatusPressure : kMemorystatusNoPressure);
        memorystatus_klist_unlock();
@@ -6015,30 +10255,30 @@ memorystatus_issue_pressure_kevent(boolean_t pressured) {
 #endif /* CONFIG_JETSAM && VM_PRESSURE_EVENTS */
 #endif /* 0 */
 
-#if CONFIG_JETSAM
 /* Coalition support */
 
 /* sorting info for a particular priority bucket */
 typedef struct memstat_sort_info {
-       coalition_t     msi_coal;
-       uint64_t        msi_page_count;
-       pid_t           msi_pid;
-       int             msi_ntasks;
+       coalition_t     msi_coal;
+       uint64_t        msi_page_count;
+       pid_t           msi_pid;
+       int             msi_ntasks;
 } memstat_sort_info_t;
 
-/* 
+/*
  * qsort from smallest page count to largest page count
  *
  * return < 0 for a < b
  *          0 for a == b
  *        > 0 for a > b
  */
-static int memstat_asc_cmp(const void *a, const void *b)
+static int
+memstat_asc_cmp(const void *a, const void *b)
 {
-        const memstat_sort_info_t *msA = (const memstat_sort_info_t *)a;
-        const memstat_sort_info_t *msB = (const memstat_sort_info_t *)b;
+       const memstat_sort_info_t *msA = (const memstat_sort_info_t *)a;
+       const memstat_sort_info_t *msB = (const memstat_sort_info_t *)b;
 
-        return (int)((uint64_t)msA->msi_page_count - (uint64_t)msB->msi_page_count);
+       return (int)((uint64_t)msA->msi_page_count - (uint64_t)msB->msi_page_count);
 }
 
 /*
@@ -6047,8 +10287,8 @@ static int memstat_asc_cmp(const void *a, const void *b)
 static int
 memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coal_sort_order)
 {
-#define MAX_SORT_PIDS          80
-#define MAX_COAL_LEADERS       10
+#define MAX_SORT_PIDS           80
+#define MAX_COAL_LEADERS        10
 
        unsigned int b = bucket_index;
        int nleaders = 0;
@@ -6059,7 +10299,7 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
        int total_pids_moved = 0;
        int i;
 
-       /* 
+       /*
         * The system is typically under memory pressure when in this
         * path, hence, we want to avoid dynamic memory allocation.
         */
@@ -6067,51 +10307,51 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
        pid_t pid_list[MAX_SORT_PIDS];
 
        if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
-                return(0);
-        }
+               return 0;
+       }
 
        /*
         * Clear the array that holds coalition leader information
         */
-       for (i=0; i < MAX_COAL_LEADERS; i++) {
+       for (i = 0; i < MAX_COAL_LEADERS; i++) {
                leaders[i].msi_coal = COALITION_NULL;
-               leaders[i].msi_page_count = 0;          /* will hold total coalition page count */
-               leaders[i].msi_pid = 0;                 /* will hold coalition leader pid */
-               leaders[i].msi_ntasks = 0;              /* will hold the number of tasks in a coalition */
+               leaders[i].msi_page_count = 0;          /* will hold total coalition page count */
+               leaders[i].msi_pid = 0;                 /* will hold coalition leader pid */
+               leaders[i].msi_ntasks = 0;              /* will hold the number of tasks in a coalition */
        }
 
-        p = memorystatus_get_first_proc_locked(&b, FALSE);
-        while (p) {
-                if (coalition_is_leader(p->task, COALITION_TYPE_JETSAM, &coal)) {
+       p = memorystatus_get_first_proc_locked(&b, FALSE);
+       while (p) {
+               if (coalition_is_leader(p->task, COALITION_TYPE_JETSAM, &coal)) {
                        if (nleaders < MAX_COAL_LEADERS) {
                                int coal_ntasks = 0;
                                uint64_t coal_page_count = coalition_get_page_count(coal, &coal_ntasks);
                                leaders[nleaders].msi_coal = coal;
                                leaders[nleaders].msi_page_count = coal_page_count;
-                               leaders[nleaders].msi_pid = p->p_pid;           /* the coalition leader */
+                               leaders[nleaders].msi_pid = p->p_pid;           /* the coalition leader */
                                leaders[nleaders].msi_ntasks = coal_ntasks;
                                nleaders++;
                        } else {
-                               /* 
+                               /*
                                 * We've hit MAX_COAL_LEADERS meaning we can handle no more coalitions.
-                                * Abandoned coalitions will linger at the tail of the priority band 
+                                * Abandoned coalitions will linger at the tail of the priority band
                                 * when this sort session ends.
                                 * TODO:  should this be an assert?
                                 */
                                printf("%s: WARNING: more than %d leaders in priority band [%d]\n",
-                                      __FUNCTION__, MAX_COAL_LEADERS, bucket_index);
+                                   __FUNCTION__, MAX_COAL_LEADERS, bucket_index);
                                break;
                        }
-                }
-                p=memorystatus_get_next_proc_locked(&b, p, FALSE);
-        }
+               }
+               p = memorystatus_get_next_proc_locked(&b, p, FALSE);
+       }
 
        if (nleaders == 0) {
                /* Nothing to sort */
-               return(0);
+               return 0;
        }
 
-       /* 
+       /*
         * Sort the coalition leader array, from smallest coalition page count
         * to largest coalition page count.  When inserted in the priority bucket,
         * smallest coalition is handled first, resulting in the last to be jetsammed.
@@ -6123,8 +10363,8 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
 #if 0
        for (i = 0; i < nleaders; i++) {
                printf("%s: coal_leader[%d of %d] pid[%d] pages[%llu] ntasks[%d]\n",
-                      __FUNCTION__, i, nleaders, leaders[i].msi_pid, leaders[i].msi_page_count,
-                       leaders[i].msi_ntasks);
+                   __FUNCTION__, i, nleaders, leaders[i].msi_pid, leaders[i].msi_page_count,
+                   leaders[i].msi_ntasks);
        }
 #endif
 
@@ -6147,8 +10387,7 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
         * based on their coalition role.
         */
        total_pids_moved = 0;
-       for (i=0; i < nleaders; i++) {
-               
+       for (i = 0; i < nleaders; i++) {
                /* a bit of bookkeeping */
                pids_moved = 0;
 
@@ -6157,30 +10396,30 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
                pids_moved += memorystatus_move_list_locked(bucket_index, pid_list, 1);
 
                /* xpc services should jetsam after extensions */
-               ntasks = coalition_get_pid_list (leaders[i].msi_coal, COALITION_ROLEMASK_XPC,
-                                                coal_sort_order, pid_list, MAX_SORT_PIDS);
+               ntasks = coalition_get_pid_list(leaders[i].msi_coal, COALITION_ROLEMASK_XPC,
+                   coal_sort_order, pid_list, MAX_SORT_PIDS);
 
                if (ntasks > 0) {
-                       pids_moved += memorystatus_move_list_locked(bucket_index, pid_list, 
-                                                                   (ntasks <= MAX_SORT_PIDS ? ntasks : MAX_SORT_PIDS));
+                       pids_moved += memorystatus_move_list_locked(bucket_index, pid_list,
+                           (ntasks <= MAX_SORT_PIDS ? ntasks : MAX_SORT_PIDS));
                }
 
                /* extensions should jetsam after unmarked processes */
-               ntasks = coalition_get_pid_list (leaders[i].msi_coal, COALITION_ROLEMASK_EXT,
-                                                coal_sort_order, pid_list, MAX_SORT_PIDS);
+               ntasks = coalition_get_pid_list(leaders[i].msi_coal, COALITION_ROLEMASK_EXT,
+                   coal_sort_order, pid_list, MAX_SORT_PIDS);
 
                if (ntasks > 0) {
                        pids_moved += memorystatus_move_list_locked(bucket_index, pid_list,
-                                                                   (ntasks <= MAX_SORT_PIDS ? ntasks : MAX_SORT_PIDS));
+                           (ntasks <= MAX_SORT_PIDS ? ntasks : MAX_SORT_PIDS));
                }
 
                /* undefined coalition members should be the first to jetsam */
-               ntasks = coalition_get_pid_list (leaders[i].msi_coal, COALITION_ROLEMASK_UNDEF,
-                                                coal_sort_order, pid_list, MAX_SORT_PIDS);
+               ntasks = coalition_get_pid_list(leaders[i].msi_coal, COALITION_ROLEMASK_UNDEF,
+                   coal_sort_order, pid_list, MAX_SORT_PIDS);
 
                if (ntasks > 0) {
-                       pids_moved += memorystatus_move_list_locked(bucket_index, pid_list, 
-                                                                   (ntasks <= MAX_SORT_PIDS ? ntasks : MAX_SORT_PIDS));
+                       pids_moved += memorystatus_move_list_locked(bucket_index, pid_list,
+                           (ntasks <= MAX_SORT_PIDS ? ntasks : MAX_SORT_PIDS));
                }
 
 #if 0
@@ -6189,27 +10428,26 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
                         * All the pids in the coalition were found in this band.
                         */
                        printf("%s: pids_moved[%d]  equal  total coalition ntasks[%d] \n", __FUNCTION__,
-                              pids_moved, leaders[i].msi_ntasks);
+                           pids_moved, leaders[i].msi_ntasks);
                } else if (pids_moved > leaders[i].msi_ntasks) {
                        /*
                         * Apparently new coalition members showed up during the sort?
                         */
                        printf("%s: pids_moved[%d] were greater than expected coalition ntasks[%d] \n", __FUNCTION__,
-                              pids_moved, leaders[i].msi_ntasks);
+                           pids_moved, leaders[i].msi_ntasks);
                } else {
                        /*
                         * Apparently not all the pids in the coalition were found in this band?
                         */
                        printf("%s: pids_moved[%d] were less than  expected coalition ntasks[%d] \n", __FUNCTION__,
-                              pids_moved, leaders[i].msi_ntasks);
+                           pids_moved, leaders[i].msi_ntasks);
                }
 #endif
 
                total_pids_moved += pids_moved;
-
        } /* end for */
 
-       return(total_pids_moved);
+       return total_pids_moved;
 }
 
 
@@ -6217,17 +10455,17 @@ memorystatus_sort_by_largest_coalition_locked(unsigned int bucket_index, int coa
  * Traverse a list of pids, searching for each within the priority band provided.
  * If pid is found, move it to the front of the priority band.
  * Never searches outside the priority band provided.
- * 
+ *
  * Input:
  *     bucket_index - jetsam priority band.
  *     pid_list - pointer to a list of pids.
  *     list_sz  - number of pids in the list.
  *
- * Pid list ordering is important in that, 
+ * Pid list ordering is important in that,
  * pid_list[n] is expected to jetsam ahead of pid_list[n+1].
  * The sort_order is set by the coalition default.
  *
- * Return: 
+ * Return:
  *     the number of pids found and hence moved within the priority band.
  */
 static int
@@ -6238,15 +10476,15 @@ memorystatus_move_list_locked(unsigned int bucket_index, pid_t *pid_list, int li
        int found_pids = 0;
 
        if ((pid_list == NULL) || (list_sz <= 0)) {
-               return(0);
+               return 0;
        }
 
        if (bucket_index >= MEMSTAT_BUCKET_COUNT) {
-                return(0);
-        }
+               return 0;
+       }
 
        current_bucket = &memstat_bucket[bucket_index];
-       for (i=0; i < list_sz; i++) {
+       for (i = 0; i < list_sz; i++) {
                unsigned int b = bucket_index;
                proc_t p = NULL;
                proc_t aProc = NULL;
@@ -6254,27 +10492,166 @@ memorystatus_move_list_locked(unsigned int bucket_index, pid_t *pid_list, int li
                int list_index;
 
                list_index = ((list_sz - 1) - i);
-                aPid = pid_list[list_index];
-
-                /* never search beyond bucket_index provided */
-                p = memorystatus_get_first_proc_locked(&b, FALSE);
-                while (p) {
-                        if (p->p_pid == aPid) {
-                                aProc = p;
-                                break;
-                        }
-                        p = memorystatus_get_next_proc_locked(&b, p, FALSE);
-                }
-
-                if (aProc == NULL) {
+               aPid = pid_list[list_index];
+
+               /* never search beyond bucket_index provided */
+               p = memorystatus_get_first_proc_locked(&b, FALSE);
+               while (p) {
+                       if (p->p_pid == aPid) {
+                               aProc = p;
+                               break;
+                       }
+                       p = memorystatus_get_next_proc_locked(&b, p, FALSE);
+               }
+
+               if (aProc == NULL) {
                        /* pid not found in this band, just skip it */
-                        continue;
-                } else {
-                        TAILQ_REMOVE(&current_bucket->list, aProc, p_memstat_list);
-                        TAILQ_INSERT_HEAD(&current_bucket->list, aProc, p_memstat_list);
+                       continue;
+               } else {
+                       TAILQ_REMOVE(&current_bucket->list, aProc, p_memstat_list);
+                       TAILQ_INSERT_HEAD(&current_bucket->list, aProc, p_memstat_list);
                        found_pids++;
-                }
-        }
-       return(found_pids);
+               }
+       }
+       return found_pids;
+}
+
+int
+memorystatus_get_proccnt_upto_priority(int32_t max_bucket_index)
+{
+       int32_t i = JETSAM_PRIORITY_IDLE;
+       int count = 0;
+
+       if (max_bucket_index >= MEMSTAT_BUCKET_COUNT) {
+               return -1;
+       }
+
+       while (i <= max_bucket_index) {
+               count += memstat_bucket[i++].count;
+       }
+
+       return count;
+}
+
+int
+memorystatus_update_priority_for_appnap(proc_t p, boolean_t is_appnap)
+{
+#if !CONFIG_JETSAM
+       if (!p || (!isApp(p)) || (p->p_memstat_state & (P_MEMSTAT_INTERNAL | P_MEMSTAT_MANAGED))) {
+               /*
+                * Ineligible processes OR system processes e.g. launchd.
+                *
+                * We also skip processes that have the P_MEMSTAT_MANAGED bit set, i.e.
+                * they're managed by assertiond. These are iOS apps that have been ported
+                * to macOS. assertiond might be in the process of modifying the app's
+                * priority / memory limit - so it might have the proc_list lock, and then try
+                * to take the task lock. Meanwhile we've entered this function with the task lock
+                * held, and we need the proc_list lock below. So we'll deadlock with assertiond.
+                *
+                * It should be fine to read the P_MEMSTAT_MANAGED bit without the proc_list
+                * lock here, since assertiond only sets this bit on process launch.
+                */
+               return -1;
+       }
+
+       /*
+        * For macOS only:
+        * We would like to use memorystatus_update() here to move the processes
+        * within the bands. Unfortunately memorystatus_update() calls
+        * memorystatus_update_priority_locked() which uses any band transitions
+        * as an indication to modify ledgers. For that it needs the task lock
+        * and since we came into this function with the task lock held, we'll deadlock.
+        *
+        * Unfortunately we can't completely disable ledger updates  because we still
+        * need the ledger updates for a subset of processes i.e. daemons.
+        * When all processes on all platforms support memory limits, we can simply call
+        * memorystatus_update().
+        *
+        * It also has some logic to deal with 'aging' which, currently, is only applicable
+        * on CONFIG_JETSAM configs. So, till every platform has CONFIG_JETSAM we'll need
+        * to do this explicit band transition.
+        */
+
+       memstat_bucket_t *current_bucket, *new_bucket;
+       int32_t priority = 0;
+
+       proc_list_lock();
+
+       if (((p->p_listflag & P_LIST_EXITED) != 0) ||
+           (p->p_memstat_state & (P_MEMSTAT_ERROR | P_MEMSTAT_TERMINATED))) {
+               /*
+                * If the process is on its way out OR
+                * jetsam has alread tried and failed to kill this process,
+                * let's skip the whole jetsam band transition.
+                */
+               proc_list_unlock();
+               return 0;
+       }
+
+       if (is_appnap) {
+               current_bucket = &memstat_bucket[p->p_memstat_effectivepriority];
+               new_bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
+               priority = JETSAM_PRIORITY_IDLE;
+       } else {
+               if (p->p_memstat_effectivepriority != JETSAM_PRIORITY_IDLE) {
+                       /*
+                        * It is possible that someone pulled this process
+                        * out of the IDLE band without updating its app-nap
+                        * parameters.
+                        */
+                       proc_list_unlock();
+                       return 0;
+               }
+
+               current_bucket = &memstat_bucket[JETSAM_PRIORITY_IDLE];
+               new_bucket = &memstat_bucket[p->p_memstat_requestedpriority];
+               priority = p->p_memstat_requestedpriority;
+       }
+
+       TAILQ_REMOVE(&current_bucket->list, p, p_memstat_list);
+       current_bucket->count--;
+
+       TAILQ_INSERT_TAIL(&new_bucket->list, p, p_memstat_list);
+       new_bucket->count++;
+
+       /*
+        * Record idle start or idle delta.
+        */
+       if (p->p_memstat_effectivepriority == priority) {
+               /*
+                * This process is not transitioning between
+                * jetsam priority buckets.  Do nothing.
+                */
+       } else if (p->p_memstat_effectivepriority == JETSAM_PRIORITY_IDLE) {
+               uint64_t now;
+               /*
+                * Transitioning out of the idle priority bucket.
+                * Record idle delta.
+                */
+               assert(p->p_memstat_idle_start != 0);
+               now = mach_absolute_time();
+               if (now > p->p_memstat_idle_start) {
+                       p->p_memstat_idle_delta = now - p->p_memstat_idle_start;
+               }
+       } else if (priority == JETSAM_PRIORITY_IDLE) {
+               /*
+                * Transitioning into the idle priority bucket.
+                * Record idle start.
+                */
+               p->p_memstat_idle_start = mach_absolute_time();
+       }
+
+       KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_MEMSTAT, BSD_MEMSTAT_CHANGE_PRIORITY), p->p_pid, priority, p->p_memstat_effectivepriority, 0, 0);
+
+       p->p_memstat_effectivepriority = priority;
+
+       proc_list_unlock();
+
+       return 0;
+
+#else /* !CONFIG_JETSAM */
+       #pragma unused(p)
+       #pragma unused(is_appnap)
+       return -1;
+#endif /* !CONFIG_JETSAM */
 }
-#endif  /* CONFIG_JETSAM */