+/*
+ * 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
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * 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,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * 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 <sys/kern_event.h>
+#include <kern/sched_prim.h>
+#include <kern/kalloc.h>
+#include <kern/assert.h>
+#include <kern/debug.h>
+#include <kern/locks.h>
+#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 <sys/sysproto.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <sys/tree.h>
+#include <sys/priv.h>
+#include <vm/vm_pageout.h>
+#include <vm/vm_protos.h>
+#include <mach/machine/sdt.h>
+#include <libkern/section_keywords.h>
+#include <stdatomic.h>
+
+#if CONFIG_FREEZE
+#include <vm/vm_map.h>
+#endif /* CONFIG_FREEZE */
+
+#include <sys/kern_memorystatus.h>
+#include <sys/kern_memorystatus_notify.h>
+
+/*
+ * Memorystatus klist structures
+ */
+struct klist memorystatus_klist;
+static lck_mtx_t memorystatus_klist_mutex;
+static void memorystatus_klist_lock(void);
+static void memorystatus_klist_unlock(void);
+
+/*
+ * Memorystatus kevent filter routines
+ */
+static int filt_memorystatusattach(struct knote *kn, struct kevent_qos_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_qos_s *kev);
+static int filt_memorystatusprocess(struct knote *kn, struct kevent_qos_s *kev);
+
+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,
+};
+
+/*
+ * Memorystatus notification events
+ */
+enum {
+ kMemorystatusNoPressure = 0x1,
+ kMemorystatusPressure = 0x2,
+ kMemorystatusLowSwap = 0x4,
+ kMemorystatusProcLimitWarn = 0x8,
+ kMemorystatusProcLimitCritical = 0x10
+};
+
+#define INTER_NOTIFICATION_DELAY (250000) /* .25 second */
+#define VM_PRESSURE_DECREASED_SMOOTHING_PERIOD 5000 /* milliseconds */
+#define WARNING_NOTIFICATION_RESTING_PERIOD 25 /* seconds */
+#define CRITICAL_NOTIFICATION_RESTING_PERIOD 25 /* seconds */
+
+/*
+ * Memorystatus notification helper routines
+ */
+static vm_pressure_level_t convert_internal_pressure_level_to_dispatch_level(vm_pressure_level_t);
+static boolean_t is_knote_registered_modify_task_pressure_bits(struct knote*, int, task_t, vm_pressure_level_t, vm_pressure_level_t);
+static void memorystatus_klist_reset_all_for_level(vm_pressure_level_t pressure_level_to_clear);
+static struct knote *vm_pressure_select_optimal_candidate_to_notify(struct klist *candidate_list, int level, boolean_t target_foreground_process);
+static void vm_dispatch_memory_pressure(void);
+kern_return_t memorystatus_update_vm_pressure(boolean_t target_foreground_process);
+
+#if VM_PRESSURE_EVENTS
+
+/*
+ * 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 */
+
+static 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 */
+
+vm_pressure_level_t memorystatus_vm_pressure_level = kVMPressureNormal;
+
+/*
+ * We use this flag to signal if we have any HWM offenders
+ * on the system. This way we can reduce the number of wakeups
+ * of the memorystatus_thread when the system is between the
+ * "pressure" and "critical" threshold.
+ *
+ * The (re-)setting of this variable is done without any locks
+ * or synchronization simply because it is not possible (currently)
+ * to keep track of HWM offenders that drop down below their memory
+ * limit and/or exit. So, we choose to burn a couple of wasted wakeups
+ * by allowing the unguarded modification of this variable.
+ */
+boolean_t memorystatus_hwm_candidates = 0;
+
+#endif /* VM_PRESSURE_EVENTS */
+
+#if CONFIG_JETSAM
+
+extern unsigned int memorystatus_available_pages;
+extern unsigned int memorystatus_available_pages_pressure;
+extern unsigned int memorystatus_available_pages_critical;
+extern unsigned int memorystatus_available_pages_critical_base;
+extern unsigned int memorystatus_available_pages_critical_idle_offset;
+
+#else /* CONFIG_JETSAM */
+
+extern uint64_t memorystatus_available_pages;
+extern uint64_t memorystatus_available_pages_pressure;
+extern uint64_t memorystatus_available_pages_critical;
+
+#endif /* CONFIG_JETSAM */
+
+extern lck_mtx_t memorystatus_jetsam_fg_band_lock;
+uint32_t memorystatus_jetsam_fg_band_waiters = 0;
+static uint64_t memorystatus_jetsam_fg_band_timestamp_ns = 0; /* nanosec */
+static uint64_t memorystatus_jetsam_fg_band_delay_ns = 5ull * 1000 * 1000 * 1000; /* nanosec */
+
+extern boolean_t(*volatile consider_buffer_cache_collect)(int);
+
+#if DEVELOPMENT || DEBUG
+SYSCTL_QUAD(_kern, OID_AUTO, memorystatus_jetsam_fg_band_delay_ns, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &memorystatus_jetsam_fg_band_delay_ns, "");
+#endif
+
+static int
+filt_memorystatusattach(struct knote *kn, __unused struct kevent_qos_s *kev)
+{
+ int error;
+
+ kn->kn_flags |= EV_CLEAR; /* automatically set */
+ kn->kn_sdata = 0; /* incoming data is ignored */
+
+ error = memorystatus_knote_register(kn);
+ if (error) {
+ knote_set_error(kn, error);
+ }
+ return 0;
+}
+
+static void
+filt_memorystatusdetach(struct knote *kn)
+{
+ memorystatus_knote_unregister(kn);
+}
+
+static int
+filt_memorystatus(struct knote *kn __unused, long hint)
+{
+ if (hint) {
+ switch (hint) {
+ case kMemorystatusNoPressure:
+ if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_NORMAL) {
+ kn->kn_fflags = NOTE_MEMORYSTATUS_PRESSURE_NORMAL;
+ }
+ break;
+ case kMemorystatusPressure:
+ if (memorystatus_vm_pressure_level == kVMPressureWarning || memorystatus_vm_pressure_level == kVMPressureUrgent) {
+ if (kn->kn_sfflags & NOTE_MEMORYSTATUS_PRESSURE_WARN) {
+ 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;
+ }
+ }
+ break;
+ case kMemorystatusLowSwap:
+ if (kn->kn_sfflags & NOTE_MEMORYSTATUS_LOW_SWAP) {
+ 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;
+ }
+ }
+
+#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_qos_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 kevent_qos_s *kev)
+{
+ int res = 0;
+
+ memorystatus_klist_lock();
+ if (kn->kn_fflags) {
+ knote_fill_kevent(kn, kev, 0);
+ res = 1;
+ }
+ memorystatus_klist_unlock();
+
+ return res;
+}
+
+static void
+memorystatus_klist_lock(void)
+{
+ lck_mtx_lock(&memorystatus_klist_mutex);
+}
+
+static void
+memorystatus_klist_unlock(void)
+{
+ lck_mtx_unlock(&memorystatus_klist_mutex);
+}
+
+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)
+{
+ int error = 0;
+
+ memorystatus_klist_lock();
+
+ /*
+ * 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 */
+
+ KNOTE_ATTACH(&memorystatus_klist, kn);
+ } else {
+ error = ENOTSUP;
+ }
+
+ memorystatus_klist_unlock();
+
+ return error;
+}
+
+void
+memorystatus_knote_unregister(struct knote *kn __unused)
+{
+ memorystatus_klist_lock();
+ KNOTE_DETACH(&memorystatus_klist, kn);
+ memorystatus_klist_unlock();
+}
+
+#if VM_PRESSURE_EVENTS
+
+#if CONFIG_MEMORYSTATUS
+
+int
+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;
+
+ ev_msg.event_code = event_code;
+
+ ev_msg.dv[0].data_length = data_length;
+ ev_msg.dv[0].data_ptr = data;
+ ev_msg.dv[1].data_length = 0;
+
+ ret = kev_post_msg(&ev_msg);
+ if (ret) {
+ printf("%s: kev_post_msg() failed, err %d\n", __func__, ret);
+ }
+
+ return ret;
+}
+
+boolean_t
+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.
+ */
+
+ 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) {
+ /*
+ * By setting the "fflags" here, we are forcing
+ * a process to deal with the case where it's
+ * bumping up into its memory limits. If we don't
+ * do this here, we will end up depending on the
+ * system pressure snapshot evaluation in
+ * filt_memorystatus().
+ */
+
+#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 {
+ /*
+ * 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).
+ */
+
+ 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) {
+ if (send_knote_count > 0) {
+ KNOTE(&memorystatus_klist, 0);
+ }
+ ret = TRUE;
+ }
+
+ memorystatus_klist_unlock();
+
+ return ret;
+}
+
+/*
+ * Can only be set by the current task on itself.
+ */
+int
+memorystatus_low_mem_privileged_listener(uint32_t op_flags)
+{
+ boolean_t set_privilege = FALSE;
+ /*
+ * Need an entitlement check here?
+ */
+ if (op_flags == MEMORYSTATUS_CMD_PRIVILEGED_LISTENER_ENABLE) {
+ set_privilege = TRUE;
+ } else if (op_flags == MEMORYSTATUS_CMD_PRIVILEGED_LISTENER_DISABLE) {
+ set_privilege = FALSE;
+ } else {
+ return EINVAL;
+ }
+
+ 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));
+}
+
+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);
+}
+
+/*
+ * 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;
+ }
+}
+
+boolean_t
+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;
+ }
+
+ 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;
+}
+
+void
+memorystatus_send_low_swap_note(void)
+{
+ struct knote *kn = NULL;
+
+ memorystatus_klist_lock();
+ SLIST_FOREACH(kn, &memorystatus_klist, kn_selnext) {
+ /* We call is_knote_registered_modify_task_pressure_bits to check if the sfflags for the
+ * current note contain NOTE_MEMORYSTATUS_LOW_SWAP. Once we find one note in the memorystatus_klist
+ * that has the NOTE_MEMORYSTATUS_LOW_SWAP flags in its sfflags set, we call KNOTE with
+ * kMemoryStatusLowSwap as the hint to process and update all knotes on the memorystatus_klist accordingly. */
+ if (is_knote_registered_modify_task_pressure_bits(kn, NOTE_MEMORYSTATUS_LOW_SWAP, NULL, 0, 0) == TRUE) {
+ KNOTE(&memorystatus_klist, kMemorystatusLowSwap);
+ break;
+ }
+ }
+
+ memorystatus_klist_unlock();
+}
+
+#endif /* CONFIG_MEMORYSTATUS */
+
+/*
+ * kn_max - knote
+ *
+ * knote_pressure_level - to check if the knote is registered for this notification level.
+ *
+ * task - task whose bits we'll be modifying
+ *
+ * pressure_level_to_clear - if the task has been notified of this past level, clear that notification bit so that if/when we revert to that level, the task will be notified again.
+ *
+ * pressure_level_to_set - the task is about to be notified of this new level. Update the task's bit notification information appropriately.
+ *
+ */
+
+static 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);
+ }
+
+ task_mark_has_been_notified(task, pressure_level_to_set);
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+static 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();
+}
+
+/*
+ * Used by the vm_pressure_thread which is
+ * signalled from within vm_pageout_scan().
+ */
+
+void
+consider_vm_pressure_events(void)
+{
+ vm_dispatch_memory_pressure();
+}
+
+static void
+vm_dispatch_memory_pressure(void)
+{
+ memorystatus_update_vm_pressure(FALSE);
+}
+
+static 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);
+ }
+
+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 kn_max;
+}
+
+static uint64_t next_warning_notification_sent_at_ts = 0;
+static uint64_t next_critical_notification_sent_at_ts = 0;
+
+boolean_t memorystatus_manual_testing_on = FALSE;
+vm_pressure_level_t memorystatus_manual_testing_level = kVMPressureNormal;
+
+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;
+ uint64_t curr_ts = mach_absolute_time();
+
+#if !CONFIG_JETSAM
+#define MAX_IDLE_KILLS 100 /* limit the number of idle kills allowed */
+
+ int idle_kill_counter = 0;
+
+ /*
+ * On desktop we take this opportunity to free up memory pressure
+ * by immediately killing idle exitable processes. We use a delay
+ * to avoid overkill. And we impose a max counter as a fail safe
+ * in case daemons re-launch too fast.
+ */
+ while ((memorystatus_vm_pressure_level != kVMPressureNormal) && (idle_kill_counter < MAX_IDLE_KILLS)) {
+ if (memorystatus_idle_exit_from_VM() == FALSE) {
+ /* No idle exitable processes left to kill */
+ break;
+ }
+ idle_kill_counter++;
+
+ if (memorystatus_manual_testing_on == TRUE) {
+ /*
+ * Skip the delay when testing
+ * the pressure notification scheme.
+ */
+ } else {
+ delay(1000000); /* 1 second */
+ }
+ }
+#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.
+ */
+ level_snapshot = memorystatus_vm_pressure_level;
+
+ if (prev_level_snapshot > level_snapshot) {
+ /*
+ * Pressure decreased? Let's take a little breather
+ * and see if this condition stays.
+ */
+ if (smoothing_window_started == FALSE) {
+ smoothing_window_started = TRUE;
+ microuptime(&smoothing_window_start_tstamp);
+ }
+
+ microuptime(&curr_tstamp);
+ timevalsub(&curr_tstamp, &smoothing_window_start_tstamp);
+ 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;
+ }
+ }
+
+ prev_level_snapshot = level_snapshot;
+ smoothing_window_started = FALSE;
+
+ memorystatus_klist_lock();
+ kn_max = vm_pressure_select_optimal_candidate_to_notify(&memorystatus_klist, level_snapshot, target_foreground_process);
+
+ if (kn_max == NULL) {
+ memorystatus_klist_unlock();
+
+ /*
+ * No more level-based clients to notify.
+ *
+ * Start the 'resting' window within which clients will not be re-notified.
+ */
+
+ if (level_snapshot != kVMPressureNormal) {
+ 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 = knote_get_kq(kn_max)->kq_p;
+
+ proc_list_lock();
+ if (target_proc != proc_ref_locked(target_proc)) {
+ target_proc = PROC_NULL;
+ proc_list_unlock();
+ memorystatus_klist_unlock();
+ continue;
+ }
+ proc_list_unlock();
+
+ target_pid = target_proc->p_pid;
+
+ task = (struct task *)(target_proc->task);
+
+ 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, 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, 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);
+
+ found_candidate = TRUE;
+ }
+ }
+
+ if (found_candidate == FALSE) {
+ proc_rele(target_proc);
+ memorystatus_klist_unlock();
+ continue;
+ }
+
+ SLIST_FOREACH_SAFE(kn_cur, &memorystatus_klist, kn_selnext, kn_temp) {
+ 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);
+ }
+ }
+ }
+
+ KNOTE(&dispatch_klist, (level_snapshot != kVMPressureNormal) ? kMemorystatusPressure : kMemorystatusNoPressure);
+
+ SLIST_FOREACH_SAFE(kn_cur, &dispatch_klist, kn_selnext, kn_temp) {
+ KNOTE_DETACH(&dispatch_klist, kn_cur);
+ KNOTE_ATTACH(&memorystatus_klist, kn_cur);
+ }
+
+ memorystatus_klist_unlock();
+
+ microuptime(&target_proc->vm_pressure_last_notify_tstamp);
+ proc_rele(target_proc);
+
+ if (memorystatus_manual_testing_on == TRUE && target_foreground_process == TRUE) {
+ break;
+ }
+
+ 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;
+
+ if (memorystatus_available_pages <= skip_delay_page_threshold) {
+ /*
+ * We are nearing the critcal mark fast and can't afford to wait between
+ * notifications.
+ */
+ sleep_interval = 0;
+ }
+#endif /* CONFIG_JETSAM */
+
+ if (sleep_interval) {
+ delay(sleep_interval);
+ }
+ }
+ }
+
+ return KERN_SUCCESS;
+}
+
+static uint32_t
+convert_internal_pressure_level_to_dispatch_level(vm_pressure_level_t internal_pressure_level)
+{
+ uint32_t dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_NORMAL;
+
+ 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 kVMPressureCritical:
+ {
+ dispatch_level = NOTE_MEMORYSTATUS_PRESSURE_CRITICAL;
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ return dispatch_level;
+}
+
+/*
+ * Notify any kexts that are waiting for notification that jetsam
+ * is approaching the foreground bands. They should use this notification
+ * to free cached memory.
+ */
+void
+memorystatus_issue_fg_band_notify(void)
+{
+ uint64_t now;
+
+ lck_mtx_lock(&memorystatus_jetsam_fg_band_lock);
+ absolutetime_to_nanoseconds(mach_absolute_time(), &now);
+ if (now - memorystatus_jetsam_fg_band_timestamp_ns < memorystatus_jetsam_fg_band_delay_ns) {
+ lck_mtx_unlock(&memorystatus_jetsam_fg_band_lock);
+ return;
+ }
+
+ if (memorystatus_jetsam_fg_band_waiters > 0) {
+ thread_wakeup(&memorystatus_jetsam_fg_band_waiters);
+ memorystatus_jetsam_fg_band_waiters = 0;
+ memorystatus_jetsam_fg_band_timestamp_ns = now;
+ }
+ lck_mtx_unlock(&memorystatus_jetsam_fg_band_lock);
+
+ /* Notify the buffer cache, file systems, etc. to jetison everything they can. */
+ if (consider_buffer_cache_collect != NULL) {
+ (void)(*consider_buffer_cache_collect)(1);
+ }
+}
+
+
+/*
+ * Memorystatus notification debugging support
+ */
+
+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 */
+ uint32_t dispatch_level = convert_internal_pressure_level_to_dispatch_level(memorystatus_vm_pressure_level);
+
+ return SYSCTL_OUT(req, &dispatch_level, sizeof(dispatch_level));
+}
+
+#if DEBUG || DEVELOPMENT
+
+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,
+ 0, 0, &sysctl_memorystatus_vm_pressure_level, "I", "");
+
+#endif /* DEBUG || DEVELOPMENT */
+
+/*
+ * 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
+
+static int
+sysctl_memorypressure_manual_trigger SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+
+ int level = 0;
+ int error = 0;
+ int pressure_level = 0;
+ int trigger_request = 0;
+ int force_purge;
+
+ error = sysctl_handle_int(oidp, &level, 0, req);
+ if (error || !req->newptr) {
+ return error;
+ }
+
+ memorystatus_manual_testing_on = TRUE;
+
+ trigger_request = (level >> 16) & 0xFFFF;
+ pressure_level = (level & 0xFFFF);
+
+ if (trigger_request < TEST_LOW_MEMORY_TRIGGER_ONE ||
+ trigger_request > TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ALL) {
+ return EINVAL;
+ }
+ switch (pressure_level) {
+ case NOTE_MEMORYSTATUS_PRESSURE_NORMAL:
+ case NOTE_MEMORYSTATUS_PRESSURE_WARN:
+ case NOTE_MEMORYSTATUS_PRESSURE_CRITICAL:
+ break;
+ default:
+ return EINVAL;
+ }
+
+ /*
+ * The pressure level is being set from user-space.
+ * And user-space uses the constants in sys/event.h
+ * 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 = vm_pageout_state.memorystatus_purge_on_warning;
+ } else if (pressure_level == NOTE_MEMORYSTATUS_PRESSURE_CRITICAL) {
+ memorystatus_manual_testing_level = kVMPressureCritical;
+ force_purge = vm_pageout_state.memorystatus_purge_on_critical;
+ }
+
+ memorystatus_vm_pressure_level = memorystatus_manual_testing_level;
+
+ /* purge according to the new pressure level */
+ switch (trigger_request) {
+ case TEST_PURGEABLE_TRIGGER_ONE:
+ case TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ONE:
+ if (force_purge == 0) {
+ /* no purging requested */
+ break;
+ }
+ vm_purgeable_object_purge_one_unlocked(force_purge);
+ break;
+ case TEST_PURGEABLE_TRIGGER_ALL:
+ case TEST_LOW_MEMORY_PURGEABLE_TRIGGER_ALL:
+ if (force_purge == 0) {
+ /* no purging requested */
+ break;
+ }
+ 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;
+ }
+
+ return 0;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, memorypressure_manual_trigger, CTLTYPE_INT | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED,
+ 0, 0, &sysctl_memorypressure_manual_trigger, "I", "");
+
+
+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, "");
+
+#if 0
+#if CONFIG_JETSAM && VM_PRESSURE_EVENTS
+static boolean_t
+memorystatus_issue_pressure_kevent(boolean_t pressured)
+{
+ memorystatus_klist_lock();
+ KNOTE(&memorystatus_klist, pressured ? kMemorystatusPressure : kMemorystatusNoPressure);
+ memorystatus_klist_unlock();
+ return TRUE;
+}
+#endif /* CONFIG_JETSAM && VM_PRESSURE_EVENTS */
+#endif /* 0 */
+
+/*
+ * 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)
+ /* Need to be root or have memorystatus entitlement */
+ if (!kauth_cred_issuser(kauth_cred_get()) && !IOTaskHasEntitlement(current_task(), MEMORYSTATUS_ENTITLEMENT)) {
+ return EPERM;
+ }
+
+ 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);
+ }
+
+ /* wake up everybody waiting for kVMPressureJetsam */
+ if (fflags == NOTE_MEMORYSTATUS_JETSAM_FG_BAND) {
+ memorystatus_issue_fg_band_notify();
+ return error;
+ }
+
+ /*
+ * 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_PROC(_kern, OID_AUTO, memorystatus_vm_pressure_send, CTLTYPE_QUAD | CTLFLAG_WR | CTLFLAG_LOCKED | CTLFLAG_MASKED | CTLFLAG_ANYBODY,
+ 0, 0, &sysctl_memorystatus_vm_pressure_send, "Q", "");
+
+#endif /* DEBUG || DEVELOPMENT */
+
+#endif /* VM_PRESSURE_EVENTS */
projects / apple / xnu.git / blobdiff