xnu-2782.1.97.tar.gz

[apple/xnu.git] / osfmk / kern / sched_prim.c

diff --git a/osfmk/kern/sched_prim.c b/osfmk/kern/sched_prim.c
index 2ed0f12e7371067fe5a52ae2f96ca82867346afb..3a88e11fb4fcf2d25f9ea6eefe81b6314aa3731f 100644 (file)
--- a/osfmk/kern/sched_prim.c
+++ b/osfmk/kern/sched_prim.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2000-2009 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.

  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 


@@ -65,18 +65,21 @@
  */
 
 #include <debug.h>
  */
 
 #include <debug.h>

-#include <mach_kdb.h>
-
-#include <ddb/db_output.h>

 
 #include <mach/mach_types.h>
 #include <mach/machine.h>
 #include <mach/policy.h>
 #include <mach/sync_policy.h>
 
 #include <mach/mach_types.h>
 #include <mach/machine.h>
 #include <mach/policy.h>
 #include <mach/sync_policy.h>

+#include <mach/thread_act.h>

 
 #include <machine/machine_routines.h>
 #include <machine/sched_param.h>
 #include <machine/machine_cpu.h>
 
 #include <machine/machine_routines.h>
 #include <machine/sched_param.h>
 #include <machine/machine_cpu.h>

+#include <machine/machlimits.h>
+
+#ifdef CONFIG_MACH_APPROXIMATE_TIME
+#include <machine/commpage.h>
+#endif

 
 #include <kern/kern_types.h>
 #include <kern/clock.h>
 
 #include <kern/kern_types.h>
 #include <kern/clock.h>


@@ -84,7 +87,6 @@
 #include <kern/cpu_number.h>
 #include <kern/cpu_data.h>
 #include <kern/debug.h>
 #include <kern/cpu_number.h>
 #include <kern/cpu_data.h>
 #include <kern/debug.h>

-#include <kern/lock.h>

 #include <kern/macro_help.h>
 #include <kern/machine.h>
 #include <kern/misc_protos.h>
 #include <kern/macro_help.h>
 #include <kern/machine.h>
 #include <kern/misc_protos.h>


@@ -92,10 +94,13 @@
 #include <kern/queue.h>
 #include <kern/sched.h>
 #include <kern/sched_prim.h>
 #include <kern/queue.h>
 #include <kern/sched.h>
 #include <kern/sched_prim.h>

+#include <kern/sfi.h>

 #include <kern/syscall_subr.h>
 #include <kern/task.h>
 #include <kern/thread.h>
 #include <kern/wait_queue.h>
 #include <kern/syscall_subr.h>
 #include <kern/task.h>
 #include <kern/thread.h>
 #include <kern/wait_queue.h>

+#include <kern/ledger.h>
+#include <kern/timer_queue.h>

 
 #include <vm/pmap.h>
 #include <vm/vm_kern.h>
 
 #include <vm/pmap.h>
 #include <vm/vm_kern.h>


@@ -107,13 +112,26 @@
 
 #include <kern/pms.h>
 
 
 #include <kern/pms.h>
 

-struct run_queue       rt_runq;
+#if defined(CONFIG_TELEMETRY) && defined(CONFIG_SCHED_TIMESHARE_CORE)
+#include <kern/telemetry.h>
+#endif
+
+struct rt_queue        rt_runq;

 #define RT_RUNQ                ((processor_t)-1)
 decl_simple_lock_data(static,rt_lock);
 
 #define RT_RUNQ                ((processor_t)-1)
 decl_simple_lock_data(static,rt_lock);
 

+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
+static struct fairshare_queue  fs_runq;
+#define FS_RUNQ                ((processor_t)-2)
+decl_simple_lock_data(static,fs_lock);
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
+

 #define                DEFAULT_PREEMPTION_RATE         100             /* (1/s) */
 int                    default_preemption_rate = DEFAULT_PREEMPTION_RATE;
 
 #define                DEFAULT_PREEMPTION_RATE         100             /* (1/s) */
 int                    default_preemption_rate = DEFAULT_PREEMPTION_RATE;
 

+#define                DEFAULT_BG_PREEMPTION_RATE      400             /* (1/s) */
+int                    default_bg_preemption_rate = DEFAULT_BG_PREEMPTION_RATE;
+

 #define                MAX_UNSAFE_QUANTA                       800
 int                    max_unsafe_quanta = MAX_UNSAFE_QUANTA;
 
 #define                MAX_UNSAFE_QUANTA                       800
 int                    max_unsafe_quanta = MAX_UNSAFE_QUANTA;
 


@@ -123,57 +141,227 @@ int                      max_poll_quanta = MAX_POLL_QUANTA;
 #define                SCHED_POLL_YIELD_SHIFT          4               /* 1/16 */
 int                    sched_poll_yield_shift = SCHED_POLL_YIELD_SHIFT;
 
 #define                SCHED_POLL_YIELD_SHIFT          4               /* 1/16 */
 int                    sched_poll_yield_shift = SCHED_POLL_YIELD_SHIFT;
 

-uint64_t       max_unsafe_computation;
-uint32_t       sched_safe_duration;

 uint64_t       max_poll_computation;
 
 uint64_t       max_poll_computation;
 

+uint64_t       max_unsafe_computation;
+uint64_t       sched_safe_duration;
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+

 uint32_t       std_quantum;
 uint32_t       min_std_quantum;
 uint32_t       std_quantum;
 uint32_t       min_std_quantum;

+uint32_t       bg_quantum;

 
 uint32_t       std_quantum_us;
 
 uint32_t       std_quantum_us;

+uint32_t       bg_quantum_us;
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+uint32_t       thread_depress_time;
+uint32_t       default_timeshare_computation;
+uint32_t       default_timeshare_constraint;

 
 uint32_t       max_rt_quantum;
 uint32_t       min_rt_quantum;
 
 
 uint32_t       max_rt_quantum;
 uint32_t       min_rt_quantum;
 

-uint32_t       sched_cswtime;
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)

 
 unsigned       sched_tick;
 uint32_t       sched_tick_interval;
 
 unsigned       sched_tick;
 uint32_t       sched_tick_interval;

+#if defined(CONFIG_TELEMETRY)
+uint32_t       sched_telemetry_interval;
+#endif /* CONFIG_TELEMETRY */

 
 uint32_t       sched_pri_shift = INT8_MAX;
 
 uint32_t       sched_pri_shift = INT8_MAX;

+uint32_t       sched_background_pri_shift = INT8_MAX;
+uint32_t       sched_combined_fgbg_pri_shift = INT8_MAX;

 uint32_t       sched_fixed_shift;
 uint32_t       sched_fixed_shift;

+uint32_t       sched_use_combined_fgbg_decay = 0;
+
+uint32_t       sched_decay_usage_age_factor = 1; /* accelerate 5/8^n usage aging */
+
+/* Allow foreground to decay past default to resolve inversions */
+#define DEFAULT_DECAY_BAND_LIMIT ((BASEPRI_FOREGROUND - BASEPRI_DEFAULT) + 2)
+int            sched_pri_decay_band_limit = DEFAULT_DECAY_BAND_LIMIT;
+
+/* Defaults for timer deadline profiling */
+#define TIMER_DEADLINE_TRACKING_BIN_1_DEFAULT 2000000 /* Timers with deadlines <=
+                                                       * 2ms */
+#define TIMER_DEADLINE_TRACKING_BIN_2_DEFAULT 5000000 /* Timers with deadlines
+                                                         <= 5ms */
+
+uint64_t timer_deadline_tracking_bin_1;
+uint64_t timer_deadline_tracking_bin_2;
+
+thread_t sched_maintenance_thread;
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static boolean_t sched_traditional_use_pset_runqueue = FALSE;
+
+__attribute__((always_inline))
+static inline run_queue_t runq_for_processor(processor_t processor)
+{
+       if (sched_traditional_use_pset_runqueue)
+               return &processor->processor_set->pset_runq;
+       else
+               return &processor->runq;
+}
+
+__attribute__((always_inline))
+static inline void runq_consider_incr_bound_count(processor_t processor, thread_t thread)
+{
+       if (thread->bound_processor == PROCESSOR_NULL)
+               return;
+    
+       assert(thread->bound_processor == processor);
+    
+       if (sched_traditional_use_pset_runqueue)
+               processor->processor_set->pset_runq_bound_count++;
+    
+       processor->runq_bound_count++;
+}
+
+__attribute__((always_inline))
+static inline void runq_consider_decr_bound_count(processor_t processor, thread_t thread)
+{
+       if (thread->bound_processor == PROCESSOR_NULL)
+               return;
+    
+       assert(thread->bound_processor == processor);
+    
+       if (sched_traditional_use_pset_runqueue)
+               processor->processor_set->pset_runq_bound_count--;
+    
+       processor->runq_bound_count--;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */

 
 

-uint32_t       sched_run_count, sched_share_count;
+uint64_t       sched_one_second_interval;
+
+uint32_t       sched_run_count, sched_share_count, sched_background_count;

 uint32_t       sched_load_average, sched_mach_factor;
 
 /* Forwards */
 uint32_t       sched_load_average, sched_mach_factor;
 
 /* Forwards */

-static void load_shift_init(void) __attribute__((section("__TEXT, initcode")));
-static void preempt_pri_init(void) __attribute__((section("__TEXT, initcode")));

 
 

-static thread_t        run_queue_dequeue(
-                                       run_queue_t             runq,
-                                       integer_t               options);
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+static void load_shift_init(void);
+static void preempt_pri_init(void);

 
 

-static thread_t        choose_thread(
-                                       processor_t             processor,
-                                       int                             priority);
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+static thread_t        thread_select(
+                                       thread_t                        thread,
+                                       processor_t                     processor,
+                                       ast_t                           reason);

 
 

+#if CONFIG_SCHED_IDLE_IN_PLACE

 static thread_t        thread_select_idle(
                                        thread_t                        thread,
                                        processor_t                     processor);
 static thread_t        thread_select_idle(
                                        thread_t                        thread,
                                        processor_t                     processor);

+#endif

 
 

-static thread_t        processor_idle(
+thread_t       processor_idle(

                                        thread_t                        thread,
                                        processor_t                     processor);
 
                                        thread_t                        thread,
                                        processor_t                     processor);
 

+ast_t
+csw_check_locked(      processor_t             processor,
+                                       processor_set_t pset,
+                                       ast_t                   check_reason);
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+

 static thread_t        steal_thread(
                                        processor_set_t         pset);
 
 static thread_t        steal_thread(
                                        processor_set_t         pset);
 

+static thread_t        steal_thread_disabled(
+                                       processor_set_t         pset) __attribute__((unused));
+
+

 static thread_t        steal_processor_thread(
                                        processor_t                     processor);
 
 static void            thread_update_scan(void);
 
 static thread_t        steal_processor_thread(
                                        processor_t                     processor);
 
 static void            thread_update_scan(void);
 

+static void processor_setrun(
+                                processor_t                    processor,
+                                thread_t                       thread,
+                                integer_t                      options);
+
+static boolean_t
+processor_enqueue(
+                                 processor_t           processor,
+                                 thread_t              thread,
+                                 integer_t             options);
+
+static boolean_t
+processor_queue_remove(
+                                          processor_t                  processor,
+                                          thread_t             thread);
+
+static boolean_t       processor_queue_empty(processor_t               processor);
+
+static ast_t           processor_csw_check(processor_t processor);
+
+static boolean_t       processor_queue_has_priority(processor_t                processor,
+                                                                                       int                             priority,
+                                                                                       boolean_t               gte);
+
+static boolean_t       should_current_thread_rechoose_processor(processor_t                    processor);
+
+static int     sched_traditional_processor_runq_count(processor_t   processor);
+
+static boolean_t       sched_traditional_with_pset_runqueue_processor_queue_empty(processor_t          processor);
+
+static uint64_t     sched_traditional_processor_runq_stats_count_sum(processor_t   processor);
+
+static uint64_t                sched_traditional_with_pset_runqueue_processor_runq_stats_count_sum(processor_t   processor);
+
+static int      sched_traditional_processor_bound_count(processor_t processor);
+
+#endif
+
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static void
+sched_traditional_processor_init(processor_t processor);
+
+static void
+sched_traditional_pset_init(processor_set_t pset);
+
+static void
+sched_traditional_with_pset_runqueue_init(void);
+
+#endif
+
+static void
+sched_realtime_init(void);
+
+static void
+sched_realtime_timebase_init(void);
+
+static void
+sched_timer_deadline_tracking_init(void);
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static sched_mode_t
+sched_traditional_initial_thread_sched_mode(task_t parent_task);
+
+static thread_t
+sched_traditional_choose_thread(
+                                processor_t     processor,
+                                int             priority,
+                       __unused ast_t           reason);
+
+#endif
+

 #if    DEBUG
 extern int debug_task;
 #define TLOG(a, fmt, args...) if(debug_task & a) kprintf(fmt, ## args)
 #if    DEBUG
 extern int debug_task;
 #define TLOG(a, fmt, args...) if(debug_task & a) kprintf(fmt, ## args)


@@ -181,13 +369,10 @@ extern int debug_task;
 #define TLOG(a, fmt, args...) do {} while (0)
 #endif
 
 #define TLOG(a, fmt, args...) do {} while (0)
 #endif
 

-#if    DEBUG
-static
+__assert_only static

 boolean_t      thread_runnable(
                                thread_t                thread);
 
 boolean_t      thread_runnable(
                                thread_t                thread);
 

-#endif /*DEBUG*/
-

 /*
  *     State machine
  *
 /*
  *     State machine
  *


@@ -214,11 +399,241 @@ boolean_t        thread_runnable(
  *
  */
 
  *
  */
 

+#if defined(CONFIG_SCHED_TIMESHARE_CORE)

 int8_t         sched_load_shifts[NRQS];
 int            sched_preempt_pri[NRQBM];
 int8_t         sched_load_shifts[NRQS];
 int            sched_preempt_pri[NRQBM];

+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+const struct sched_dispatch_table sched_traditional_dispatch = {
+       .init                                           = sched_traditional_init,
+       .timebase_init                                  = sched_traditional_timebase_init,
+       .processor_init                                 = sched_traditional_processor_init,
+       .pset_init                                      = sched_traditional_pset_init,
+       .maintenance_continuation                       = sched_traditional_maintenance_continue,
+       .choose_thread                                  = sched_traditional_choose_thread,
+       .steal_thread                                   = steal_thread,
+       .compute_priority                               = compute_priority,
+       .choose_processor                               = choose_processor,
+       .processor_enqueue                              = processor_enqueue,
+       .processor_queue_shutdown                       = processor_queue_shutdown,
+       .processor_queue_remove                         = processor_queue_remove,
+       .processor_queue_empty                          = processor_queue_empty,
+       .priority_is_urgent                             = priority_is_urgent,
+       .processor_csw_check                            = processor_csw_check,
+       .processor_queue_has_priority                   = processor_queue_has_priority,
+       .initial_quantum_size                           = sched_traditional_initial_quantum_size,
+       .initial_thread_sched_mode                      = sched_traditional_initial_thread_sched_mode,
+       .can_update_priority                            = can_update_priority,
+       .update_priority                                = update_priority,
+       .lightweight_update_priority                    = lightweight_update_priority,
+       .quantum_expire                                 = sched_traditional_quantum_expire,
+       .should_current_thread_rechoose_processor       = should_current_thread_rechoose_processor,
+       .processor_runq_count                           = sched_traditional_processor_runq_count,
+       .processor_runq_stats_count_sum                 = sched_traditional_processor_runq_stats_count_sum,
+       .fairshare_init                                 = sched_traditional_fairshare_init,
+       .fairshare_runq_count                           = sched_traditional_fairshare_runq_count,
+       .fairshare_runq_stats_count_sum                 = sched_traditional_fairshare_runq_stats_count_sum,
+       .fairshare_enqueue                              = sched_traditional_fairshare_enqueue,
+       .fairshare_dequeue                              = sched_traditional_fairshare_dequeue,
+       .fairshare_queue_remove                         = sched_traditional_fairshare_queue_remove,
+       .processor_bound_count                          = sched_traditional_processor_bound_count,
+       .thread_update_scan                             = thread_update_scan,
+       .direct_dispatch_to_idle_processors             = TRUE,
+};
+
+const struct sched_dispatch_table sched_traditional_with_pset_runqueue_dispatch = {
+       .init                                           = sched_traditional_with_pset_runqueue_init,
+       .timebase_init                                  = sched_traditional_timebase_init,
+       .processor_init                                 = sched_traditional_processor_init,
+       .pset_init                                      = sched_traditional_pset_init,
+       .maintenance_continuation                       = sched_traditional_maintenance_continue,
+       .choose_thread                                  = sched_traditional_choose_thread,
+       .steal_thread                                   = steal_thread,
+       .compute_priority                               = compute_priority,
+       .choose_processor                               = choose_processor,
+       .processor_enqueue                              = processor_enqueue,
+       .processor_queue_shutdown                       = processor_queue_shutdown,
+       .processor_queue_remove                         = processor_queue_remove,
+       .processor_queue_empty                          = sched_traditional_with_pset_runqueue_processor_queue_empty,
+       .priority_is_urgent                             = priority_is_urgent,
+       .processor_csw_check                            = processor_csw_check,
+       .processor_queue_has_priority                   = processor_queue_has_priority,
+       .initial_quantum_size                           = sched_traditional_initial_quantum_size,
+       .initial_thread_sched_mode                      = sched_traditional_initial_thread_sched_mode,
+       .can_update_priority                            = can_update_priority,
+       .update_priority                                = update_priority,
+       .lightweight_update_priority                    = lightweight_update_priority,
+       .quantum_expire                                 = sched_traditional_quantum_expire,
+       .should_current_thread_rechoose_processor       = should_current_thread_rechoose_processor,
+       .processor_runq_count                           = sched_traditional_processor_runq_count,
+       .processor_runq_stats_count_sum                 = sched_traditional_with_pset_runqueue_processor_runq_stats_count_sum,
+       .fairshare_init                                 = sched_traditional_fairshare_init,
+       .fairshare_runq_count                           = sched_traditional_fairshare_runq_count,
+       .fairshare_runq_stats_count_sum                 = sched_traditional_fairshare_runq_stats_count_sum,
+       .fairshare_enqueue                              = sched_traditional_fairshare_enqueue,
+       .fairshare_dequeue                              = sched_traditional_fairshare_dequeue,
+       .fairshare_queue_remove                         = sched_traditional_fairshare_queue_remove,
+       .processor_bound_count                          = sched_traditional_processor_bound_count,
+       .thread_update_scan                             = thread_update_scan,
+       .direct_dispatch_to_idle_processors             = FALSE,
+};
+
+#endif
+
+const struct sched_dispatch_table *sched_current_dispatch = NULL;
+
+/*
+ * Statically allocate a buffer to hold the longest possible
+ * scheduler description string, as currently implemented.
+ * bsd/kern/kern_sysctl.c has a corresponding definition in bsd/
+ * to export to userspace via sysctl(3). If either version
+ * changes, update the other.
+ *
+ * Note that in addition to being an upper bound on the strings
+ * in the kernel, it's also an exact parameter to PE_get_default(),
+ * which interrogates the device tree on some platforms. That
+ * API requires the caller know the exact size of the device tree
+ * property, so we need both a legacy size (32) and the current size
+ * (48) to deal with old and new device trees. The device tree property
+ * is similarly padded to a fixed size so that the same kernel image
+ * can run on multiple devices with different schedulers configured
+ * in the device tree.
+ */
+#define SCHED_STRING_MAX_LENGTH (48)
+
+char sched_string[SCHED_STRING_MAX_LENGTH];
+static enum sched_enum _sched_enum __attribute__((used)) = sched_enum_unknown;
+
+/* Global flag which indicates whether Background Stepper Context is enabled */
+static int cpu_throttle_enabled = 1;

 
 void
 sched_init(void)
 
 void
 sched_init(void)

+{
+       char sched_arg[SCHED_STRING_MAX_LENGTH] = { '\0' };
+
+       /* Check for runtime selection of the scheduler algorithm */
+       if (!PE_parse_boot_argn("sched", sched_arg, sizeof (sched_arg))) {
+               /* If no boot-args override, look in device tree */
+               if (!PE_get_default("kern.sched", sched_arg,
+                                                       SCHED_STRING_MAX_LENGTH)) {
+                       sched_arg[0] = '\0';
+               }
+       }
+
+       
+       if (!PE_parse_boot_argn("sched_pri_decay_limit", &sched_pri_decay_band_limit, sizeof(sched_pri_decay_band_limit))) {
+               /* No boot-args, check in device tree */
+               if (!PE_get_default("kern.sched_pri_decay_limit",
+                                                       &sched_pri_decay_band_limit,
+                                                       sizeof(sched_pri_decay_band_limit))) {
+                       /* Allow decay all the way to normal limits */
+                       sched_pri_decay_band_limit = DEFAULT_DECAY_BAND_LIMIT;
+               }
+       }
+
+       kprintf("Setting scheduler priority decay band limit %d\n", sched_pri_decay_band_limit);
+
+       if (strlen(sched_arg) > 0) {
+               if (0) {
+                       /* Allow pattern below */
+#if defined(CONFIG_SCHED_TRADITIONAL)
+               } else if (0 == strcmp(sched_arg, kSchedTraditionalString)) {
+                       sched_current_dispatch = &sched_traditional_dispatch;
+                       _sched_enum = sched_enum_traditional;
+                       strlcpy(sched_string, kSchedTraditionalString, sizeof(sched_string));
+               } else if (0 == strcmp(sched_arg, kSchedTraditionalWithPsetRunqueueString)) {
+                       sched_current_dispatch = &sched_traditional_with_pset_runqueue_dispatch;
+                       _sched_enum = sched_enum_traditional_with_pset_runqueue;
+                       strlcpy(sched_string, kSchedTraditionalWithPsetRunqueueString, sizeof(sched_string));
+#endif
+#if defined(CONFIG_SCHED_PROTO)
+               } else if (0 == strcmp(sched_arg, kSchedProtoString)) {
+                       sched_current_dispatch = &sched_proto_dispatch;
+                       _sched_enum = sched_enum_proto;
+                       strlcpy(sched_string, kSchedProtoString, sizeof(sched_string));
+#endif
+#if defined(CONFIG_SCHED_GRRR)
+               } else if (0 == strcmp(sched_arg, kSchedGRRRString)) {
+                       sched_current_dispatch = &sched_grrr_dispatch;
+                       _sched_enum = sched_enum_grrr;
+                       strlcpy(sched_string, kSchedGRRRString, sizeof(sched_string));
+#endif
+#if defined(CONFIG_SCHED_MULTIQ)
+               } else if (0 == strcmp(sched_arg, kSchedMultiQString)) {
+                       sched_current_dispatch = &sched_multiq_dispatch;
+                       _sched_enum = sched_enum_multiq;
+                       strlcpy(sched_string, kSchedMultiQString, sizeof(sched_string));
+               } else if (0 == strcmp(sched_arg, kSchedDualQString)) {
+                       sched_current_dispatch = &sched_dualq_dispatch;
+                       _sched_enum = sched_enum_dualq;
+                       strlcpy(sched_string, kSchedDualQString, sizeof(sched_string));
+#endif
+               } else {
+#if defined(CONFIG_SCHED_TRADITIONAL)
+                       printf("Unrecognized scheduler algorithm: %s\n", sched_arg);
+                       printf("Scheduler: Using instead: %s\n", kSchedTraditionalWithPsetRunqueueString);
+
+                       sched_current_dispatch = &sched_traditional_with_pset_runqueue_dispatch;
+                       _sched_enum = sched_enum_traditional_with_pset_runqueue;
+                       strlcpy(sched_string, kSchedTraditionalWithPsetRunqueueString, sizeof(sched_string));
+#else
+                       panic("Unrecognized scheduler algorithm: %s", sched_arg);
+#endif
+               }
+               kprintf("Scheduler: Runtime selection of %s\n", sched_string);
+       } else {
+#if   defined(CONFIG_SCHED_MULTIQ)
+               sched_current_dispatch = &sched_multiq_dispatch;
+               _sched_enum = sched_enum_multiq;
+               strlcpy(sched_string, kSchedMultiQString, sizeof(sched_string));
+#elif defined(CONFIG_SCHED_TRADITIONAL)
+               sched_current_dispatch = &sched_traditional_with_pset_runqueue_dispatch;
+               _sched_enum = sched_enum_traditional_with_pset_runqueue;
+               strlcpy(sched_string, kSchedTraditionalWithPsetRunqueueString, sizeof(sched_string));
+#elif defined(CONFIG_SCHED_PROTO)
+               sched_current_dispatch = &sched_proto_dispatch;
+               _sched_enum = sched_enum_proto;
+               strlcpy(sched_string, kSchedProtoString, sizeof(sched_string));
+#elif defined(CONFIG_SCHED_GRRR)
+               sched_current_dispatch = &sched_grrr_dispatch;
+               _sched_enum = sched_enum_grrr;
+               strlcpy(sched_string, kSchedGRRRString, sizeof(sched_string));
+#else
+#error No default scheduler implementation
+#endif
+               kprintf("Scheduler: Default of %s\n", sched_string);
+       }
+       
+       SCHED(init)();
+       SCHED(fairshare_init)();
+       sched_realtime_init();
+       ast_init();
+       sched_timer_deadline_tracking_init();
+
+       SCHED(pset_init)(&pset0);
+       SCHED(processor_init)(master_processor);
+}
+
+void
+sched_timebase_init(void)
+{
+       uint64_t        abstime;
+       
+       clock_interval_to_absolutetime_interval(1, NSEC_PER_SEC, &abstime);
+       sched_one_second_interval = abstime;
+       
+       SCHED(timebase_init)();
+       sched_realtime_timebase_init();
+}
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+void
+sched_traditional_init(void)

 {
        /*
         * Calculate the timeslicing quantum
 {
        /*
         * Calculate the timeslicing quantum


@@ -230,19 +645,19 @@ sched_init(void)
 
        printf("standard timeslicing quantum is %d us\n", std_quantum_us);
 
 
        printf("standard timeslicing quantum is %d us\n", std_quantum_us);
 

-       sched_safe_duration = (2 * max_unsafe_quanta / default_preemption_rate) *
-                                                                                       (1 << SCHED_TICK_SHIFT);
+       if (default_bg_preemption_rate < 1)
+               default_bg_preemption_rate = DEFAULT_BG_PREEMPTION_RATE;
+       bg_quantum_us = (1000 * 1000) / default_bg_preemption_rate;
+
+       printf("standard background quantum is %d us\n", bg_quantum_us);

 
        load_shift_init();
        preempt_pri_init();
 
        load_shift_init();
        preempt_pri_init();

-       simple_lock_init(&rt_lock, 0);
-       run_queue_init(&rt_runq);

        sched_tick = 0;
        sched_tick = 0;

-       ast_init();

 }
 
 void
 }
 
 void

-sched_timebase_init(void)
+sched_traditional_timebase_init(void)

 {
        uint64_t        abstime;
        uint32_t        shift;
 {
        uint64_t        abstime;
        uint32_t        shift;


@@ -258,16 +673,11 @@ sched_timebase_init(void)
        assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
        min_std_quantum = (uint32_t)abstime;
 
        assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
        min_std_quantum = (uint32_t)abstime;
 

-       /* smallest rt computaton (50 us) */
-       clock_interval_to_absolutetime_interval(50, NSEC_PER_USEC, &abstime);
-       assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
-       min_rt_quantum = (uint32_t)abstime;
-
-       /* maximum rt computation (50 ms) */
+       /* quantum for background tasks */

        clock_interval_to_absolutetime_interval(
        clock_interval_to_absolutetime_interval(

-                                                       50, 1000*NSEC_PER_USEC, &abstime);
+                                                       bg_quantum_us, NSEC_PER_USEC, &abstime);

        assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
        assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);

-       max_rt_quantum = (uint32_t)abstime;
+       bg_quantum = (uint32_t)abstime;

 
        /* scheduler tick interval */
        clock_interval_to_absolutetime_interval(USEC_PER_SEC >> SCHED_TICK_SHIFT,
 
        /* scheduler tick interval */
        clock_interval_to_absolutetime_interval(USEC_PER_SEC >> SCHED_TICK_SHIFT,


@@ -284,10 +694,94 @@ sched_timebase_init(void)
                abstime >>= 1;
        sched_fixed_shift = shift;
 
                abstime >>= 1;
        sched_fixed_shift = shift;
 

-       max_unsafe_computation = max_unsafe_quanta * std_quantum;
-       max_poll_computation = max_poll_quanta * std_quantum;
+       max_unsafe_computation = ((uint64_t)max_unsafe_quanta) * std_quantum;
+       sched_safe_duration = 2 * ((uint64_t)max_unsafe_quanta) * std_quantum;
+       
+       max_poll_computation = ((uint64_t)max_poll_quanta) * std_quantum;
+       thread_depress_time = 1 * std_quantum;
+       default_timeshare_computation = std_quantum / 2;
+       default_timeshare_constraint = std_quantum;
+
+#if defined(CONFIG_TELEMETRY)
+       /* interval for high frequency telemetry */
+       clock_interval_to_absolutetime_interval(10, NSEC_PER_MSEC, &abstime);
+       assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
+       sched_telemetry_interval = (uint32_t)abstime;
+#endif
+}
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static void
+sched_traditional_processor_init(processor_t processor)
+{
+       if (!sched_traditional_use_pset_runqueue) {
+               run_queue_init(&processor->runq);
+       }
+       processor->runq_bound_count = 0;
+}
+
+static void
+sched_traditional_pset_init(processor_set_t pset)
+{
+       if (sched_traditional_use_pset_runqueue) {
+               run_queue_init(&pset->pset_runq);
+       }
+       pset->pset_runq_bound_count = 0;
+}
+
+static void
+sched_traditional_with_pset_runqueue_init(void)
+{
+       sched_traditional_init();
+       sched_traditional_use_pset_runqueue = TRUE;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
+void
+sched_traditional_fairshare_init(void)
+{
+       simple_lock_init(&fs_lock, 0);
+       
+       fs_runq.count = 0;
+       queue_init(&fs_runq.queue);
+}
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
+
+static void
+sched_realtime_init(void)
+{
+       simple_lock_init(&rt_lock, 0);
+
+       rt_runq.count = 0;
+       queue_init(&rt_runq.queue);
+}
+
+static void
+sched_realtime_timebase_init(void)
+{
+       uint64_t abstime;
+
+       /* smallest rt computaton (50 us) */
+       clock_interval_to_absolutetime_interval(50, NSEC_PER_USEC, &abstime);
+       assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
+       min_rt_quantum = (uint32_t)abstime;
+
+       /* maximum rt computation (50 ms) */
+       clock_interval_to_absolutetime_interval(
+               50, 1000*NSEC_PER_USEC, &abstime);
+       assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
+       max_rt_quantum = (uint32_t)abstime;
+

 }
 
 }
 

+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+

 /*
  * Set up values for timeshare
  * loading factors.
 /*
  * Set up values for timeshare
  * loading factors.


@@ -298,10 +792,45 @@ load_shift_init(void)
        int8_t          k, *p = sched_load_shifts;
        uint32_t        i, j;
 
        int8_t          k, *p = sched_load_shifts;
        uint32_t        i, j;
 

+       uint32_t        sched_decay_penalty = 1;
+
+       if (PE_parse_boot_argn("sched_decay_penalty", &sched_decay_penalty, sizeof (sched_decay_penalty))) {
+               kprintf("Overriding scheduler decay penalty %u\n", sched_decay_penalty);
+       }
+
+       if (PE_parse_boot_argn("sched_decay_usage_age_factor", &sched_decay_usage_age_factor, sizeof (sched_decay_usage_age_factor))) {
+               kprintf("Overriding scheduler decay usage age factor %u\n", sched_decay_usage_age_factor);
+       }
+
+       if (PE_parse_boot_argn("sched_use_combined_fgbg_decay", &sched_use_combined_fgbg_decay, sizeof (sched_use_combined_fgbg_decay))) {
+               kprintf("Overriding schedule fg/bg decay calculation: %u\n", sched_use_combined_fgbg_decay);
+       }
+
+       if (sched_decay_penalty == 0) {
+               /*
+                * There is no penalty for timeshare threads for using too much
+                * CPU, so set all load shifts to INT8_MIN. Even under high load,
+                * sched_pri_shift will be >INT8_MAX, and there will be no
+                * penalty applied to threads (nor will sched_usage be updated per
+                * thread).
+                */
+               for (i = 0; i < NRQS; i++) {
+                       sched_load_shifts[i] = INT8_MIN;
+               }
+
+               return;
+       }
+

        *p++ = INT8_MIN; *p++ = 0;
 
        *p++ = INT8_MIN; *p++ = 0;
 

-       for (i = j = 2, k = 1; i < NRQS; ++k) {
-               for (j <<= 1; i < j; ++i)
+       /*
+        * For a given system load "i", the per-thread priority
+        * penalty per quantum of CPU usage is ~2^k priority
+        * levels. "sched_decay_penalty" can cause more
+        * array entries to be filled with smaller "k" values
+        */
+       for (i = 2, j = 1 << sched_decay_penalty, k = 1; i < NRQS; ++k) {
+               for (j <<= 1; (i < j) && (i < NRQS); ++i)

                        *p++ = k;
        }
 }
                        *p++ = k;
        }
 }


@@ -311,13 +840,15 @@ preempt_pri_init(void)
 {
        int             i, *p = sched_preempt_pri;
 
 {
        int             i, *p = sched_preempt_pri;
 

-       for (i = BASEPRI_FOREGROUND + 1; i < MINPRI_KERNEL; ++i)
+       for (i = BASEPRI_FOREGROUND; i < MINPRI_KERNEL; ++i)

                setbit(i, p);
 
        for (i = BASEPRI_PREEMPT; i <= MAXPRI; ++i)
                setbit(i, p);
 }
 
                setbit(i, p);
 
        for (i = BASEPRI_PREEMPT; i <= MAXPRI; ++i)
                setbit(i, p);
 }
 

+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+

 /*
  *     Thread wait timer expiration.
  */
 /*
  *     Thread wait timer expiration.
  */


@@ -341,73 +872,6 @@ thread_timer_expire(
        splx(s);
 }
 
        splx(s);
 }
 

-#ifndef        __LP64__
-
-/*
- *     thread_set_timer:
- *
- *     Set a timer for the current thread, if the thread
- *     is ready to wait.  Must be called between assert_wait()
- *     and thread_block().
- */
-void
-thread_set_timer(
-       uint32_t                interval,
-       uint32_t                scale_factor)
-{
-       thread_t                thread = current_thread();
-       uint64_t                deadline;
-       spl_t                   s;
-
-       s = splsched();
-       thread_lock(thread);
-       if ((thread->state & TH_WAIT) != 0) {
-               clock_interval_to_deadline(interval, scale_factor, &deadline);
-               if (!timer_call_enter(&thread->wait_timer, deadline))
-                       thread->wait_timer_active++;
-               thread->wait_timer_is_set = TRUE;
-       }
-       thread_unlock(thread);
-       splx(s);
-}
-
-void
-thread_set_timer_deadline(
-       uint64_t                deadline)
-{
-       thread_t                thread = current_thread();
-       spl_t                   s;
-
-       s = splsched();
-       thread_lock(thread);
-       if ((thread->state & TH_WAIT) != 0) {
-               if (!timer_call_enter(&thread->wait_timer, deadline))
-                       thread->wait_timer_active++;
-               thread->wait_timer_is_set = TRUE;
-       }
-       thread_unlock(thread);
-       splx(s);
-}
-
-void
-thread_cancel_timer(void)
-{
-       thread_t                thread = current_thread();
-       spl_t                   s;
-
-       s = splsched();
-       thread_lock(thread);
-       if (thread->wait_timer_is_set) {
-               if (timer_call_cancel(&thread->wait_timer))
-                       thread->wait_timer_active--;
-               thread->wait_timer_is_set = FALSE;
-       }
-       thread_unlock(thread);
-       splx(s);
-}
-
-#endif /* __LP64__ */
-

 /*
  *     thread_unblock:
  *
 /*
  *     thread_unblock:
  *


@@ -423,6 +887,8 @@ thread_unblock(
        wait_result_t   wresult)
 {
        boolean_t               result = FALSE;
        wait_result_t   wresult)
 {
        boolean_t               result = FALSE;

+       thread_t                cthread = current_thread();
+       uint32_t                new_run_count;

 
        /*
         *      Set wait_result.
 
        /*
         *      Set wait_result.


@@ -452,41 +918,99 @@ thread_unblock(
                /*
                 *      Update run counts.
                 */
                /*
                 *      Update run counts.
                 */

-               sched_run_incr();
-               if (thread->sched_mode & TH_MODE_TIMESHARE)
-                       sched_share_incr();
+               new_run_count = sched_run_incr(thread);
+               if (thread->sched_mode == TH_MODE_TIMESHARE) {
+                       sched_share_incr(thread);
+
+                       if (thread->sched_flags & TH_SFLAG_THROTTLED)
+                               sched_background_incr(thread);
+               }

        }
        else {
                /*
                 *      Signal if idling on another processor.
                 */
        }
        else {
                /*
                 *      Signal if idling on another processor.
                 */

+#if CONFIG_SCHED_IDLE_IN_PLACE

                if (thread->state & TH_IDLE) {
                        processor_t             processor = thread->last_processor;
 
                        if (processor != current_processor())
                                machine_signal_idle(processor);
                }
                if (thread->state & TH_IDLE) {
                        processor_t             processor = thread->last_processor;
 
                        if (processor != current_processor())
                                machine_signal_idle(processor);
                }

+#else
+               assert((thread->state & TH_IDLE) == 0);
+#endif
+
+               new_run_count = sched_run_count; /* updated in thread_select_idle() */

                result = TRUE;
        }
 
        /*
         * Calculate deadline for real-time threads.
         */
                result = TRUE;
        }
 
        /*
         * Calculate deadline for real-time threads.
         */

-       if (thread->sched_mode & TH_MODE_REALTIME) {
-               thread->realtime.deadline = mach_absolute_time();
-               thread->realtime.deadline += thread->realtime.constraint;
+       if (thread->sched_mode == TH_MODE_REALTIME) {
+               uint64_t                ctime;
+
+               ctime = mach_absolute_time();
+               thread->realtime.deadline = thread->realtime.constraint + ctime;

        }
 
        /*
         * Clear old quantum, fail-safe computation, etc.
         */
        }
 
        /*
         * Clear old quantum, fail-safe computation, etc.
         */

-       thread->current_quantum = 0;
+       thread->quantum_remaining = 0;

        thread->computation_metered = 0;
        thread->reason = AST_NONE;
 
        thread->computation_metered = 0;
        thread->reason = AST_NONE;
 

-       KERNEL_DEBUG_CONSTANT(
+       /* Obtain power-relevant interrupt and "platform-idle exit" statistics.
+        * We also account for "double hop" thread signaling via
+        * the thread callout infrastructure.
+        * DRK: consider removing the callout wakeup counters in the future
+        * they're present for verification at the moment.
+        */
+       boolean_t aticontext, pidle;
+       ml_get_power_state(&aticontext, &pidle);
+
+       if (__improbable(aticontext && !(thread_get_tag_internal(thread) & THREAD_TAG_CALLOUT))) {
+               ledger_credit(thread->t_ledger, task_ledgers.interrupt_wakeups, 1);
+               DTRACE_SCHED2(iwakeup, struct thread *, thread, struct proc *, thread->task->bsd_info);
+
+               uint64_t ttd = PROCESSOR_DATA(current_processor(), timer_call_ttd);
+
+               if (ttd) {
+                       if (ttd <= timer_deadline_tracking_bin_1)
+                               thread->thread_timer_wakeups_bin_1++;
+                       else
+                               if (ttd <= timer_deadline_tracking_bin_2)
+                                       thread->thread_timer_wakeups_bin_2++;
+               }
+
+               if (pidle) {
+                       ledger_credit(thread->t_ledger, task_ledgers.platform_idle_wakeups, 1);
+               }
+
+       } else if (thread_get_tag_internal(cthread) & THREAD_TAG_CALLOUT) {
+               if (cthread->callout_woken_from_icontext) {
+                       ledger_credit(thread->t_ledger, task_ledgers.interrupt_wakeups, 1);
+                       thread->thread_callout_interrupt_wakeups++;
+                       if (cthread->callout_woken_from_platform_idle) {
+                               ledger_credit(thread->t_ledger, task_ledgers.platform_idle_wakeups, 1);
+                               thread->thread_callout_platform_idle_wakeups++;
+                       }
+                       
+                       cthread->callout_woke_thread = TRUE;
+               }
+       }
+       
+       if (thread_get_tag_internal(thread) & THREAD_TAG_CALLOUT) {
+               thread->callout_woken_from_icontext = aticontext;
+               thread->callout_woken_from_platform_idle = pidle;
+               thread->callout_woke_thread = FALSE;
+       }
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,

                MACHDBG_CODE(DBG_MACH_SCHED,MACH_MAKE_RUNNABLE) | DBG_FUNC_NONE,
                MACHDBG_CODE(DBG_MACH_SCHED,MACH_MAKE_RUNNABLE) | DBG_FUNC_NONE,

-                                       (uintptr_t)thread_tid(thread), thread->sched_pri, 0, 0, 0);
+               (uintptr_t)thread_tid(thread), thread->sched_pri, thread->wait_result, new_run_count, 0);

 
        DTRACE_SCHED2(wakeup, struct thread *, thread, struct proc *, thread->task->bsd_info);
 
 
        DTRACE_SCHED2(wakeup, struct thread *, thread, struct proc *, thread->task->bsd_info);
 


@@ -554,19 +1078,20 @@ thread_mark_wait_locked(
        at_safe_point = (interruptible == THREAD_ABORTSAFE);
 
        if (    interruptible == THREAD_UNINT                   ||
        at_safe_point = (interruptible == THREAD_ABORTSAFE);
 
        if (    interruptible == THREAD_UNINT                   ||

-                       !(thread->sched_mode & TH_MODE_ABORT)   ||
+                       !(thread->sched_flags & TH_SFLAG_ABORT) ||

                        (!at_safe_point &&
                        (!at_safe_point &&

-                               (thread->sched_mode & TH_MODE_ABORTSAFELY))) {
+                               (thread->sched_flags & TH_SFLAG_ABORTSAFELY))) {

 
 

-               DTRACE_SCHED(sleep);
+               if ( !(thread->state & TH_TERMINATE))
+                       DTRACE_SCHED(sleep);

 
                thread->state |= (interruptible) ? TH_WAIT : (TH_WAIT | TH_UNINT);
                thread->at_safe_point = at_safe_point;
                return (thread->wait_result = THREAD_WAITING);
        }
        else
 
                thread->state |= (interruptible) ? TH_WAIT : (TH_WAIT | TH_UNINT);
                thread->at_safe_point = at_safe_point;
                return (thread->wait_result = THREAD_WAITING);
        }
        else

-       if (thread->sched_mode & TH_MODE_ABORTSAFELY)
-               thread->sched_mode &= ~TH_MODE_ISABORTED;
+       if (thread->sched_flags & TH_SFLAG_ABORTSAFELY)
+               thread->sched_flags &= ~TH_SFLAG_ABORTED_MASK;

 
        return (thread->wait_result = THREAD_INTERRUPTED);
 }
 
        return (thread->wait_result = THREAD_INTERRUPTED);
 }


@@ -633,7 +1158,12 @@ assert_wait(
        register wait_queue_t   wq;
        register int            index;
 
        register wait_queue_t   wq;
        register int            index;
 

-       assert(event != NO_EVENT);
+       if(event == NO_EVENT)
+               panic("assert_wait() called with NO_EVENT");
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+               VM_KERNEL_UNSLIDE(event), 0, 0, 0, 0);

 
        index = wait_hash(event);
        wq = &wait_queues[index];
 
        index = wait_hash(event);
        wq = &wait_queues[index];


@@ -653,7 +1183,9 @@ assert_wait_timeout(
        uint64_t                        deadline;
        spl_t                           s;
 
        uint64_t                        deadline;
        spl_t                           s;
 

-       assert(event != NO_EVENT);
+       if(event == NO_EVENT)
+               panic("assert_wait_timeout() called with NO_EVENT");
+

        wqueue = &wait_queues[wait_hash(event)];
 
        s = splsched();
        wqueue = &wait_queues[wait_hash(event)];
 
        s = splsched();


@@ -661,8 +1193,65 @@ assert_wait_timeout(
        thread_lock(thread);
 
        clock_interval_to_deadline(interval, scale_factor, &deadline);
        thread_lock(thread);
 
        clock_interval_to_deadline(interval, scale_factor, &deadline);

+       
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+               VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+       
+       wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t, event),
+                                                 interruptible, 
+                                                 TIMEOUT_URGENCY_SYS_NORMAL,
+                                                 deadline, 0,
+                                                 thread);
+
+       thread_unlock(thread);
+       wait_queue_unlock(wqueue);
+       splx(s);
+
+       return (wresult);
+}
+
+wait_result_t
+assert_wait_timeout_with_leeway(
+       event_t                         event,
+       wait_interrupt_t        interruptible,
+       wait_timeout_urgency_t  urgency,
+       uint32_t                        interval,
+       uint32_t                        leeway,
+       uint32_t                        scale_factor)
+{
+       thread_t                        thread = current_thread();
+       wait_result_t           wresult;
+       wait_queue_t            wqueue;
+       uint64_t                        deadline;
+       uint64_t                        abstime;
+       uint64_t                        slop;
+       uint64_t                        now;
+       spl_t                           s;
+
+       now = mach_absolute_time();
+       clock_interval_to_absolutetime_interval(interval, scale_factor, &abstime);
+       deadline = now + abstime;
+
+       clock_interval_to_absolutetime_interval(leeway, scale_factor, &slop);
+
+       if(event == NO_EVENT)
+               panic("assert_wait_timeout_with_leeway() called with NO_EVENT");
+
+       wqueue = &wait_queues[wait_hash(event)];
+
+       s = splsched();
+       wait_queue_lock(wqueue);
+       thread_lock(thread);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+               VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+       

        wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t, event),
        wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t, event),

-                                                                                                       interruptible, deadline, thread);
+                                                 interruptible,
+                                                 urgency, deadline, slop,
+                                                 thread);

 
        thread_unlock(thread);
        wait_queue_unlock(wqueue);
 
        thread_unlock(thread);
        wait_queue_unlock(wqueue);


@@ -689,8 +1278,14 @@ assert_wait_deadline(
        wait_queue_lock(wqueue);
        thread_lock(thread);
 
        wait_queue_lock(wqueue);
        thread_lock(thread);
 

+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+               VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+

        wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t,event),
        wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t,event),

-                                                                                                       interruptible, deadline, thread);
+                                                 interruptible, 
+                                                 TIMEOUT_URGENCY_SYS_NORMAL, deadline, 0,
+                                                 thread);

 
        thread_unlock(thread);
        wait_queue_unlock(wqueue);
 
        thread_unlock(thread);
        wait_queue_unlock(wqueue);


@@ -699,90 +1294,85 @@ assert_wait_deadline(
        return (wresult);
 }
 
        return (wresult);
 }
 

-/*
- *     thread_sleep_fast_usimple_lock:
- *
- *     Cause the current thread to wait until the specified event
- *     occurs.  The specified simple_lock is unlocked before releasing
- *     the cpu and re-acquired as part of waking up.
- *
- *     This is the simple lock sleep interface for components that use a
- *     faster version of simple_lock() than is provided by usimple_lock().
- */
-__private_extern__ wait_result_t
-thread_sleep_fast_usimple_lock(
-       event_t                 event,
-       simple_lock_t           lock,
-       wait_interrupt_t        interruptible)
+wait_result_t
+assert_wait_deadline_with_leeway(
+       event_t                         event,
+       wait_interrupt_t        interruptible,
+       wait_timeout_urgency_t  urgency,
+       uint64_t                        deadline,
+       uint64_t                        leeway)

 {
 {

-       wait_result_t res;
+       thread_t                        thread = current_thread();
+       wait_result_t           wresult;
+       wait_queue_t            wqueue;
+       spl_t                           s;

 
 

-       res = assert_wait(event, interruptible);
-       if (res == THREAD_WAITING) {
-               simple_unlock(lock);
-               res = thread_block(THREAD_CONTINUE_NULL);
-               simple_lock(lock);
-       }
-       return res;
-}
+       if(event == NO_EVENT)
+               panic("assert_wait_deadline_with_leeway() called with NO_EVENT");

 
 

+       wqueue = &wait_queues[wait_hash(event)];

 
 

-/*
- *     thread_sleep_usimple_lock:
- *
- *     Cause the current thread to wait until the specified event
- *     occurs.  The specified usimple_lock is unlocked before releasing
- *     the cpu and re-acquired as part of waking up.
- *
- *     This is the simple lock sleep interface for components where
- *     simple_lock() is defined in terms of usimple_lock().
- */
-wait_result_t
-thread_sleep_usimple_lock(
-       event_t                 event,
-       usimple_lock_t          lock,
-       wait_interrupt_t        interruptible)
-{
-       wait_result_t res;
+       s = splsched();
+       wait_queue_lock(wqueue);
+       thread_lock(thread);

 
 

-       res = assert_wait(event, interruptible);
-       if (res == THREAD_WAITING) {
-               usimple_unlock(lock);
-               res = thread_block(THREAD_CONTINUE_NULL);
-               usimple_lock(lock);
-       }
-       return res;
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+               VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+
+       wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t,event),
+                                                 interruptible, 
+                                                 urgency, deadline, leeway,
+                                                 thread);
+
+       thread_unlock(thread);
+       wait_queue_unlock(wqueue);
+       splx(s);
+
+       return (wresult);

 }
 
 /*
 }
 
 /*

- *     thread_sleep_lock_write:
+ * thread_isoncpu:

  *
  *

- *     Cause the current thread to wait until the specified event
- *     occurs.  The specified (write) lock is unlocked before releasing
- *     the cpu. The (write) lock will be re-acquired before returning.
+ * Return TRUE if a thread is running on a processor such that an AST
+ * is needed to pull it out of userspace execution, or if executing in
+ * the kernel, bring to a context switch boundary that would cause
+ * thread state to be serialized in the thread PCB.
+ * 
+ * Thread locked, returns the same way. While locked, fields
+ * like "state" cannot change. "runq" can change only from set to unset.

  */
  */

-wait_result_t
-thread_sleep_lock_write(
-       event_t                 event,
-       lock_t                  *lock,
-       wait_interrupt_t interruptible)
+static inline boolean_t
+thread_isoncpu(thread_t thread)

 {
 {

-       wait_result_t   res;
+       /* Not running or runnable */
+       if (!(thread->state & TH_RUN))
+               return (FALSE);

 
 

-       res = assert_wait(event, interruptible);
-       if (res == THREAD_WAITING) {
-               lock_write_done(lock);
-               res = thread_block(THREAD_CONTINUE_NULL);
-               lock_write(lock);
-       }
-       return res;
+       /* Waiting on a runqueue, not currently running */
+       /* TODO: This is invalid - it can get dequeued without thread lock, but not context switched. */
+       if (thread->runq != PROCESSOR_NULL)
+               return (FALSE);
+
+       /*
+        * Thread must be running on a processor, or
+        * about to run, or just did run. In all these
+        * cases, an AST to the processor is needed
+        * to guarantee that the thread is kicked out
+        * of userspace and the processor has
+        * context switched (and saved register state).
+        */
+       return (TRUE);

 }
 
 /*
  * thread_stop:
  *
  * Force a preemption point for a thread and wait
 }
 
 /*
  * thread_stop:
  *
  * Force a preemption point for a thread and wait

- * for it to stop running.  Arbitrates access among
+ * for it to stop running on a CPU. If a stronger
+ * guarantee is requested, wait until no longer
+ * runnable. Arbitrates access among

  * multiple stop requests. (released by unstop)
  *
  * The thread must enter a wait state and stop via a
  * multiple stop requests. (released by unstop)
  *
  * The thread must enter a wait state and stop via a


@@ -792,10 +1382,12 @@ thread_sleep_lock_write(
  */
 boolean_t
 thread_stop(
  */
 boolean_t
 thread_stop(

-       thread_t                thread)
+       thread_t                thread,
+       boolean_t       until_not_runnable)

 {
        wait_result_t   wresult;
        spl_t                   s = splsched();
 {
        wait_result_t   wresult;
        spl_t                   s = splsched();

+       boolean_t               oncpu;

 
        wake_lock(thread);
        thread_lock(thread);
 
        wake_lock(thread);
        thread_lock(thread);


@@ -821,11 +1413,15 @@ thread_stop(
 
        thread->state |= TH_SUSP;
 
 
        thread->state |= TH_SUSP;
 

-       while (thread->state & TH_RUN) {
-               processor_t             processor = thread->last_processor;
-
-               if (processor != PROCESSOR_NULL && processor->active_thread == thread)
+       while ((oncpu = thread_isoncpu(thread)) ||
+                  (until_not_runnable && (thread->state & TH_RUN))) {
+               processor_t             processor;
+               
+               if (oncpu) {
+                       assert(thread->state & TH_RUN);
+                       processor = thread->chosen_processor;

                        cause_ast_check(processor);
                        cause_ast_check(processor);

+               }

 
                thread->wake_active = TRUE;
                thread_unlock(thread);
 
                thread->wake_active = TRUE;
                thread_unlock(thread);


@@ -850,6 +1446,13 @@ thread_stop(
        thread_unlock(thread);
        wake_unlock(thread);
        splx(s);
        thread_unlock(thread);
        wake_unlock(thread);
        splx(s);

+       
+       /*
+        * We return with the thread unlocked. To prevent it from
+        * transitioning to a runnable state (or from TH_RUN to
+        * being on the CPU), the caller must ensure the thread
+        * is stopped via an external means (such as an AST)
+        */

 
        return (TRUE);
 }
 
        return (TRUE);
 }


@@ -906,19 +1509,32 @@ thread_unstop(
  */
 void
 thread_wait(
  */
 void
 thread_wait(

-       thread_t                thread)
+       thread_t        thread,
+       boolean_t       until_not_runnable)

 {
        wait_result_t   wresult;
 {
        wait_result_t   wresult;

-       spl_t                   s = splsched();
+       boolean_t       oncpu;
+       processor_t     processor;
+       spl_t           s = splsched();

 
        wake_lock(thread);
        thread_lock(thread);
 
 
        wake_lock(thread);
        thread_lock(thread);
 

-       while (thread->state & TH_RUN) {
-               processor_t             processor = thread->last_processor;
+       /*
+        * Wait until not running on a CPU.  If stronger requirement
+        * desired, wait until not runnable.  Assumption: if thread is
+        * on CPU, then TH_RUN is set, so we're not waiting in any case
+        * where the original, pure "TH_RUN" check would have let us 
+        * finish.
+        */
+       while ((oncpu = thread_isoncpu(thread)) ||
+                       (until_not_runnable && (thread->state & TH_RUN))) {

 
 

-               if (processor != PROCESSOR_NULL && processor->active_thread == thread)
+               if (oncpu) {
+                       assert(thread->state & TH_RUN);
+                       processor = thread->chosen_processor;

                        cause_ast_check(processor);
                        cause_ast_check(processor);

+               }

 
                thread->wake_active = TRUE;
                thread_unlock(thread);
 
                thread->wake_active = TRUE;
                thread_unlock(thread);


@@ -962,7 +1578,7 @@ clear_wait_internal(
        wait_result_t   wresult)
 {
        wait_queue_t    wq = thread->wait_queue;
        wait_result_t   wresult)
 {
        wait_queue_t    wq = thread->wait_queue;

-       int                             i = LockTimeOut;
+       uint32_t        i = LockTimeOut;

 
        do {
                if (wresult == THREAD_INTERRUPTED && (thread->state & TH_UNINT))
 
        do {
                if (wresult == THREAD_INTERRUPTED && (thread->state & TH_UNINT))


@@ -986,7 +1602,7 @@ clear_wait_internal(
                }
 
                return (thread_go(thread, wresult));
                }
 
                return (thread_go(thread, wresult));

-       } while (--i > 0);
+       } while ((--i > 0) || machine_timeout_suspended());

 
        panic("clear_wait_internal: deadlock: thread=%p, wq=%p, cpu=%d\n",
                  thread, wq, cpu_number());
 
        panic("clear_wait_internal: deadlock: thread=%p, wq=%p, cpu=%d\n",
                  thread, wq, cpu_number());


@@ -1033,15 +1649,29 @@ kern_return_t
 thread_wakeup_prim(
        event_t                 event,
        boolean_t               one_thread,
 thread_wakeup_prim(
        event_t                 event,
        boolean_t               one_thread,

-       wait_result_t   result)
+       wait_result_t           result)
+{
+       return (thread_wakeup_prim_internal(event, one_thread, result, -1));
+}
+
+
+kern_return_t
+thread_wakeup_prim_internal(
+       event_t                 event,
+       boolean_t               one_thread,
+       wait_result_t           result,
+       int                     priority)

 {
        register wait_queue_t   wq;
        register int                    index;
 
 {
        register wait_queue_t   wq;
        register int                    index;
 

+       if(event == NO_EVENT)
+               panic("thread_wakeup_prim() called with NO_EVENT");
+

        index = wait_hash(event);
        wq = &wait_queues[index];
        if (one_thread)
        index = wait_hash(event);
        wq = &wait_queues[index];
        if (one_thread)

-           return (wait_queue_wakeup_one(wq, event, result));
+               return (wait_queue_wakeup_one(wq, event, result, priority));

        else
            return (wait_queue_wakeup_all(wq, event, result));
 }
        else
            return (wait_queue_wakeup_all(wq, event, result));
 }


@@ -1050,6 +1680,7 @@ thread_wakeup_prim(
  *     thread_bind:
  *
  *     Force the current thread to execute on the specified processor.
  *     thread_bind:
  *
  *     Force the current thread to execute on the specified processor.

+ *     Takes effect after the next thread_block().

  *
  *     Returns the previous binding.  PROCESSOR_NULL means
  *     not bound.
  *
  *     Returns the previous binding.  PROCESSOR_NULL means
  *     not bound.


@@ -1067,6 +1698,9 @@ thread_bind(
        s = splsched();
        thread_lock(self);
 
        s = splsched();
        thread_lock(self);
 

+       /* <rdar://problem/15102234> */
+       assert(self->sched_pri < BASEPRI_RTQUEUES);
+

        prev = self->bound_processor;
        self->bound_processor = processor;
 
        prev = self->bound_processor;
        self->bound_processor = processor;
 


@@ -1076,6 +1710,66 @@ thread_bind(
        return (prev);
 }
 
        return (prev);
 }
 

+/* Invoked prior to idle entry to determine if, on SMT capable processors, an SMT
+ * rebalancing opportunity exists when a core is (instantaneously) idle, but
+ * other SMT-capable cores may be over-committed. TODO: some possible negatives:
+ * IPI thrash if this core does not remain idle following the load balancing ASTs
+ * Idle "thrash", when IPI issue is followed by idle entry/core power down
+ * followed by a wakeup shortly thereafter.
+ */
+
+/* Invoked with pset locked, returns with pset unlocked */
+#if (DEVELOPMENT || DEBUG)
+int sched_smt_balance = 1;
+#endif
+
+static void
+sched_SMT_balance(processor_t cprocessor, processor_set_t cpset) {
+       processor_t ast_processor = NULL;
+
+#if (DEVELOPMENT || DEBUG)
+       if (__improbable(sched_smt_balance == 0))
+               goto smt_balance_exit;
+#endif
+       
+       assert(cprocessor == current_processor());
+       if (cprocessor->is_SMT == FALSE)
+               goto smt_balance_exit;
+
+       processor_t sib_processor = cprocessor->processor_secondary ? cprocessor->processor_secondary : cprocessor->processor_primary;
+
+       /* Determine if both this processor and its sibling are idle,
+        * indicating an SMT rebalancing opportunity.
+        */
+       if (sib_processor->state != PROCESSOR_IDLE)
+               goto smt_balance_exit;
+
+       processor_t sprocessor;
+
+       sprocessor = (processor_t)queue_first(&cpset->active_queue);
+
+       while (!queue_end(&cpset->active_queue, (queue_entry_t)sprocessor)) {
+               if ((sprocessor->state == PROCESSOR_RUNNING) &&
+                   (sprocessor->processor_primary != sprocessor) &&
+                   (sprocessor->processor_primary->state == PROCESSOR_RUNNING) &&
+                   (sprocessor->current_pri < BASEPRI_RTQUEUES) &&
+                   ((cpset->pending_AST_cpu_mask & (1U << sprocessor->cpu_id)) == 0)) {
+                       assert(sprocessor != cprocessor);
+                       ast_processor = sprocessor;
+                       break;
+               }
+               sprocessor = (processor_t)queue_next((queue_entry_t)sprocessor);
+       }
+
+smt_balance_exit:
+       pset_unlock(cpset);
+
+       if (ast_processor) {
+               KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_SMT_BALANCE), ast_processor->cpu_id, ast_processor->state, ast_processor->processor_primary->state, 0, 0);
+               cause_ast_check(ast_processor);
+       }
+}
+

 /*
  *     thread_select:
  *
 /*
  *     thread_select:
  *


@@ -1086,24 +1780,42 @@ thread_bind(
 static thread_t
 thread_select(
        thread_t                        thread,
 static thread_t
 thread_select(
        thread_t                        thread,

-       processor_t                     processor)
+       processor_t                     processor,
+       ast_t                           reason)

 {
        processor_set_t         pset = processor->processor_set;
        thread_t                        new_thread = THREAD_NULL;
 {
        processor_set_t         pset = processor->processor_set;
        thread_t                        new_thread = THREAD_NULL;

-       boolean_t                       inactive_state;
+
+       assert(processor == current_processor());

 
        do {
                /*
                 *      Update the priority.
                 */
 
        do {
                /*
                 *      Update the priority.
                 */

-               if (thread->sched_stamp != sched_tick)
-                       update_priority(thread);
-
+               if (SCHED(can_update_priority)(thread))
+                       SCHED(update_priority)(thread);
+               

                processor->current_pri = thread->sched_pri;
                processor->current_pri = thread->sched_pri;

+               processor->current_thmode = thread->sched_mode;
+               processor->current_sfi_class = thread->sfi_class;

 
                pset_lock(pset);
 
 
                pset_lock(pset);
 

-               inactive_state = processor->state != PROCESSOR_SHUTDOWN && machine_processor_is_inactive(processor);
+               assert(processor->state != PROCESSOR_OFF_LINE);
+
+               if (processor->processor_primary != processor) {
+                       /*
+                        * Should this secondary SMT processor attempt to find work? For pset runqueue systems,
+                        * we should look for work only under the same conditions that choose_processor()
+                        * would have assigned work, which is when all primary processors have been assigned work.
+                        *
+                        * An exception is that bound threads are dispatched to a processor without going through
+                        * choose_processor(), so in those cases we should continue trying to dequeue work.
+                        */
+                       if (!SCHED(processor_bound_count)(processor) && !queue_empty(&pset->idle_queue) && !rt_runq.count) {
+                               goto idle;
+                       }
+               }

 
                simple_lock(&rt_lock);
 
 
                simple_lock(&rt_lock);
 


@@ -1113,39 +1825,21 @@ thread_select(
                 *      bound to a different processor, nor be in the wrong
                 *      processor set.
                 */
                 *      bound to a different processor, nor be in the wrong
                 *      processor set.
                 */

-               if (
-#if CONFIG_EMBEDDED
-                               ((thread->state & ~TH_SUSP) == TH_RUN)                                  &&
-#else
-                               thread->state == TH_RUN                                                                 &&
-#endif
-                               (thread->sched_pri >= BASEPRI_RTQUEUES          ||
-                                processor->processor_meta == PROCESSOR_META_NULL ||
-                                processor->processor_meta->primary == processor)               &&
-                               (thread->bound_processor == PROCESSOR_NULL      ||
-                                thread->bound_processor == processor)                  &&
-                               (thread->affinity_set == AFFINITY_SET_NULL      ||
-                                thread->affinity_set->aset_pset == pset)                       ) {
-                       if (    thread->sched_pri >= BASEPRI_RTQUEUES   &&
-                                               first_timeslice(processor)                              ) {
-                               if (rt_runq.highq >= BASEPRI_RTQUEUES) {
-                                       register run_queue_t    runq = &rt_runq;
-                                       register queue_t                q;
-
-                                       q = runq->queues + runq->highq;
-                                       if (((thread_t)q->next)->realtime.deadline <
-                                                                                                       processor->deadline) {
-                                               thread = (thread_t)q->next;
-                                               ((queue_entry_t)thread)->next->prev = q;
-                                               q->next = ((queue_entry_t)thread)->next;
+               if (((thread->state & ~TH_SUSP) == TH_RUN) &&
+                   (thread->sched_pri >= BASEPRI_RTQUEUES     || processor->processor_primary == processor) &&
+                   (thread->bound_processor == PROCESSOR_NULL || thread->bound_processor == processor)      &&
+                   (thread->affinity_set == AFFINITY_SET_NULL || thread->affinity_set->aset_pset == pset)) {
+                       if (thread->sched_pri >= BASEPRI_RTQUEUES && first_timeslice(processor)) {
+                               if (rt_runq.count > 0) {
+                                       thread_t next_rt;
+
+                                       next_rt = (thread_t)queue_first(&rt_runq.queue);
+                                       if (next_rt->realtime.deadline < processor->deadline &&
+                                          (next_rt->bound_processor == PROCESSOR_NULL || next_rt->bound_processor == processor)) {
+                                               thread = (thread_t)dequeue_head(&rt_runq.queue);

                                                thread->runq = PROCESSOR_NULL;
                                                thread->runq = PROCESSOR_NULL;

-                                               runq->count--; runq->urgency--;
-                                               assert(runq->urgency >= 0);
-                                               if (queue_empty(q)) {
-                                                       if (runq->highq != IDLEPRI)
-                                                               clrbit(MAXPRI - runq->highq, runq->bitmap);
-                                                       runq->highq = MAXPRI - ffsbit(runq->bitmap);
-                                               }
+                                               SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+                                               rt_runq.count--;

                                        }
                                }
 
                                        }
                                }
 


@@ -1158,16 +1852,11 @@ thread_select(
                                return (thread);
                        }
 
                                return (thread);
                        }
 

-                       if (!inactive_state && rt_runq.highq < thread->sched_pri &&
-                                       (new_thread = choose_thread(processor, thread->sched_pri)) == THREAD_NULL) {
+                       if ((thread->sched_mode != TH_MODE_FAIRSHARE || SCHED(fairshare_runq_count)() == 0) && (rt_runq.count == 0 || BASEPRI_RTQUEUES < thread->sched_pri) && (new_thread = SCHED(choose_thread)(processor, thread->sched_mode == TH_MODE_FAIRSHARE ? MINPRI : thread->sched_pri, reason)) == THREAD_NULL) {

 
                                simple_unlock(&rt_lock);
 
 
                                simple_unlock(&rt_lock);
 

-                               /* I am the highest priority runnable (non-idle) thread */
-
-                               pset_pri_hint(pset, processor, processor->current_pri);
-
-                               pset_count_hint(pset, processor, processor->runq.count);
+                               /* This thread is still the highest priority runnable (non-idle) thread */

 
                                processor->deadline = UINT64_MAX;
 
 
                                processor->deadline = UINT64_MAX;
 


@@ -1178,16 +1867,10 @@ thread_select(
                }
 
                if (new_thread != THREAD_NULL ||
                }
 
                if (new_thread != THREAD_NULL ||

-                               (processor->runq.highq >= rt_runq.highq &&
-                                        (new_thread = choose_thread(processor, MINPRI)) != THREAD_NULL)) {
+                               (SCHED(processor_queue_has_priority)(processor, rt_runq.count == 0 ? IDLEPRI : BASEPRI_RTQUEUES, TRUE) &&
+                                        (new_thread = SCHED(choose_thread)(processor, MINPRI, reason)) != THREAD_NULL)) {

                                simple_unlock(&rt_lock);
 
                                simple_unlock(&rt_lock);
 

-                               if (!inactive_state) {
-                                       pset_pri_hint(pset, processor, new_thread->sched_pri);
-
-                                       pset_count_hint(pset, processor, processor->runq.count);
-                               }
-

                                processor->deadline = UINT64_MAX;
                                pset_unlock(pset);
 
                                processor->deadline = UINT64_MAX;
                                pset_unlock(pset);
 


@@ -1195,79 +1878,85 @@ thread_select(
                }
 
                if (rt_runq.count > 0) {
                }
 
                if (rt_runq.count > 0) {

-                       thread = run_queue_dequeue(&rt_runq, SCHED_HEADQ);
-                       simple_unlock(&rt_lock);
+                       thread_t next_rt = (thread_t)queue_first(&rt_runq.queue);

 
 

-                       processor->deadline = thread->realtime.deadline;
-                       pset_unlock(pset);
+                       if (__probable((next_rt->bound_processor == NULL || (next_rt->bound_processor == processor)))) {
+                               thread = (thread_t)dequeue_head(&rt_runq.queue);
+
+                               thread->runq = PROCESSOR_NULL;
+                               SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+                               rt_runq.count--;
+
+                               simple_unlock(&rt_lock);

 
 

-                       return (thread);
+                               processor->deadline = thread->realtime.deadline;
+                               pset_unlock(pset);
+
+                               return (thread);
+                       }

                }
 
                simple_unlock(&rt_lock);
 
                }
 
                simple_unlock(&rt_lock);
 

-               processor->deadline = UINT64_MAX;
-
-               /*
-                *      Set processor inactive based on
-                *      indication from the platform code.
+               /* No realtime threads and no normal threads on the per-processor
+                * runqueue. Finally check for global fairshare threads.

                 */
                 */

-               if (inactive_state) {
-                       if (processor->state == PROCESSOR_RUNNING)
-                               remqueue(&pset->active_queue, (queue_entry_t)processor);
-                       else
-                       if (processor->state == PROCESSOR_IDLE)
-                               remqueue(&pset->idle_queue, (queue_entry_t)processor);
-
-                       processor->state = PROCESSOR_INACTIVE;
+               if ((new_thread = SCHED(fairshare_dequeue)()) != THREAD_NULL) {

 
 

+                       processor->deadline = UINT64_MAX;

                        pset_unlock(pset);
                        pset_unlock(pset);

-
-                       return (processor->idle_thread);
+                       
+                       return (new_thread);

                }
                }

+                       
+               processor->deadline = UINT64_MAX;

 
                /*
                 *      No runnable threads, attempt to steal
                 *      from other processors.
                 */
 
                /*
                 *      No runnable threads, attempt to steal
                 *      from other processors.
                 */

-               new_thread = steal_thread(pset);
-               if (new_thread != THREAD_NULL)
+               new_thread = SCHED(steal_thread)(pset);
+               if (new_thread != THREAD_NULL) {

                        return (new_thread);
                        return (new_thread);

+               }

 
                /*
                 *      If other threads have appeared, shortcut
                 *      around again.
                 */
 
                /*
                 *      If other threads have appeared, shortcut
                 *      around again.
                 */

-               if (processor->runq.count > 0 || rt_runq.count > 0)
+               if (!SCHED(processor_queue_empty)(processor) || rt_runq.count > 0 || SCHED(fairshare_runq_count)() > 0)

                        continue;
 
                pset_lock(pset);
 
                        continue;
 
                pset_lock(pset);
 

+       idle:

                /*
                 *      Nothing is runnable, so set this processor idle if it
                 *      was running.
                 */
                if (processor->state == PROCESSOR_RUNNING) {
                /*
                 *      Nothing is runnable, so set this processor idle if it
                 *      was running.
                 */
                if (processor->state == PROCESSOR_RUNNING) {

-                       remqueue(&pset->active_queue, (queue_entry_t)processor);
+                       remqueue((queue_entry_t)processor);

                        processor->state = PROCESSOR_IDLE;
 
                        processor->state = PROCESSOR_IDLE;
 

-                       if (processor->processor_meta == PROCESSOR_META_NULL || processor->processor_meta->primary == processor) {
+                       if (processor->processor_primary == processor) {

                                enqueue_head(&pset->idle_queue, (queue_entry_t)processor);
                                enqueue_head(&pset->idle_queue, (queue_entry_t)processor);

-                               pset->low_pri = pset->low_count = processor;

                        }
                        else {
                        }
                        else {

-                               enqueue_head(&processor->processor_meta->idle_queue, (queue_entry_t)processor);
-                               pset_unlock(pset);
-                               return (processor->idle_thread);
+                               enqueue_head(&pset->idle_secondary_queue, (queue_entry_t)processor);

                        }
                }
 
                        }
                }
 

-               pset_unlock(pset);
+               /* Invoked with pset locked, returns with pset unlocked */
+               sched_SMT_balance(processor, pset);

 
 

+#if CONFIG_SCHED_IDLE_IN_PLACE

                /*
                 *      Choose idle thread if fast idle is not possible.
                 */
                /*
                 *      Choose idle thread if fast idle is not possible.
                 */

-               if ((thread->state & (TH_IDLE|TH_TERMINATE|TH_SUSP)) || !(thread->state & TH_WAIT) || thread->wake_active)
+               if (processor->processor_primary != processor)
+                       return (processor->idle_thread);
+
+               if ((thread->state & (TH_IDLE|TH_TERMINATE|TH_SUSP)) || !(thread->state & TH_WAIT) || thread->wake_active || thread->sched_pri >= BASEPRI_RTQUEUES)

                        return (processor->idle_thread);
 
                /*
                        return (processor->idle_thread);
 
                /*


@@ -1277,11 +1966,23 @@ thread_select(
                 */
                new_thread = thread_select_idle(thread, processor);
 
                 */
                new_thread = thread_select_idle(thread, processor);
 

+#else /* !CONFIG_SCHED_IDLE_IN_PLACE */
+               
+               /*
+                * Do a full context switch to idle so that the current
+                * thread can start running on another processor without
+                * waiting for the fast-idled processor to wake up.
+                */
+               return (processor->idle_thread);
+
+#endif /* !CONFIG_SCHED_IDLE_IN_PLACE */
+

        } while (new_thread == THREAD_NULL);
 
        return (new_thread);
 }
 
        } while (new_thread == THREAD_NULL);
 
        return (new_thread);
 }
 

+#if CONFIG_SCHED_IDLE_IN_PLACE

 /*
  *     thread_select_idle:
  *
 /*
  *     thread_select_idle:
  *


@@ -1295,20 +1996,37 @@ thread_select_idle(
        processor_t             processor)
 {
        thread_t                new_thread;
        processor_t             processor)
 {
        thread_t                new_thread;

+       uint64_t                arg1, arg2;
+       int                     urgency;

 
 

-       if (thread->sched_mode & TH_MODE_TIMESHARE)
-               sched_share_decr();
-       sched_run_decr();
+       if (thread->sched_mode == TH_MODE_TIMESHARE) {
+               if (thread->sched_flags & TH_SFLAG_THROTTLED)
+                       sched_background_decr(thread);
+
+               sched_share_decr(thread);
+       }
+       sched_run_decr(thread);

 
        thread->state |= TH_IDLE;
        processor->current_pri = IDLEPRI;
 
        thread->state |= TH_IDLE;
        processor->current_pri = IDLEPRI;

+       processor->current_thmode = TH_MODE_NONE;
+       processor->current_sfi_class = SFI_CLASS_KERNEL;

 
 

+       /* Reload precise timing global policy to thread-local policy */
+       thread->precise_user_kernel_time = use_precise_user_kernel_time(thread);
+       

        thread_unlock(thread);
 
        /*
         *      Switch execution timing to processor idle thread.
         */
        processor->last_dispatch = mach_absolute_time();
        thread_unlock(thread);
 
        /*
         *      Switch execution timing to processor idle thread.
         */
        processor->last_dispatch = mach_absolute_time();

+
+#ifdef CONFIG_MACH_APPROXIMATE_TIME
+       commpage_update_mach_approximate_time(processor->last_dispatch);
+#endif
+
+       thread->last_run_time = processor->last_dispatch;

        thread_timer_event(processor->last_dispatch, &processor->idle_thread->system_timer);
        PROCESSOR_DATA(processor, kernel_timer) = &processor->idle_thread->system_timer;
 
        thread_timer_event(processor->last_dispatch, &processor->idle_thread->system_timer);
        PROCESSOR_DATA(processor, kernel_timer) = &processor->idle_thread->system_timer;
 


@@ -1320,6 +2038,8 @@ thread_select_idle(
 
        (*thread->sched_call)(SCHED_CALL_BLOCK, thread);
 
 
        (*thread->sched_call)(SCHED_CALL_BLOCK, thread);
 

+       thread_tell_urgency(THREAD_URGENCY_NONE, 0, 0, NULL);
+

        /*
         *      Enable interrupts and perform idling activities.  No
         *      preemption due to TH_IDLE being set.
        /*
         *      Enable interrupts and perform idling activities.  No
         *      preemption due to TH_IDLE being set.


@@ -1343,25 +2063,61 @@ thread_select_idle(
                PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
 
                thread_quantum_init(thread);
                PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
 
                thread_quantum_init(thread);

-
-               processor->quantum_end = processor->last_dispatch + thread->current_quantum;
-               timer_call_enter1(&processor->quantum_timer, thread, processor->quantum_end);
+               processor->quantum_end = processor->last_dispatch + thread->quantum_remaining;
+               timer_call_enter1(&processor->quantum_timer, thread, processor->quantum_end, TIMER_CALL_SYS_CRITICAL | TIMER_CALL_LOCAL);

                processor->timeslice = 1;
 
                thread->computation_epoch = processor->last_dispatch;
        }
 
                processor->timeslice = 1;
 
                thread->computation_epoch = processor->last_dispatch;
        }
 

-       thread->state &= ~TH_IDLE;
-
-       sched_run_incr();
-       if (thread->sched_mode & TH_MODE_TIMESHARE)
-               sched_share_incr();
+       thread->state &= ~TH_IDLE;
+
+       /*
+        * If we idled in place, simulate a context switch back
+        * to the original priority of the thread so that the
+        * platform layer cannot distinguish this from a true
+        * switch to the idle thread.
+        */
+
+       urgency = thread_get_urgency(thread, &arg1, &arg2);
+
+       thread_tell_urgency(urgency, arg1, arg2, new_thread);
+
+       sched_run_incr(thread);
+       if (thread->sched_mode == TH_MODE_TIMESHARE) {
+               sched_share_incr(thread);
+
+               if (thread->sched_flags & TH_SFLAG_THROTTLED)
+                       sched_background_incr(thread);
+       }
+
+       return (new_thread);
+}
+#endif /* CONFIG_SCHED_IDLE_IN_PLACE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL) 
+static thread_t
+sched_traditional_choose_thread(
+                                processor_t     processor,
+                                int             priority,
+                       __unused ast_t           reason)
+{
+       thread_t thread;
+       
+       thread = choose_thread_from_runq(processor, runq_for_processor(processor), priority);
+       if (thread != THREAD_NULL) {
+               runq_consider_decr_bound_count(processor, thread);
+       }
+       
+       return thread;
+}
+
+#endif /* defined(CONFIG_SCHED_TRADITIONAL)  */

 
 

-       return (new_thread);
-}
+#if defined(CONFIG_SCHED_TRADITIONAL)

 
 /*
 
 /*

- *     choose_thread:
+ *     choose_thread_from_runq:

  *
  *     Locate a thread to execute from the processor run queue
  *     and return it.  Only choose a thread with greater or equal
  *
  *     Locate a thread to execute from the processor run queue
  *     and return it.  Only choose a thread with greater or equal


@@ -1370,12 +2126,12 @@ thread_select_idle(
  *     Associated pset must be locked.  Returns THREAD_NULL
  *     on failure.
  */
  *     Associated pset must be locked.  Returns THREAD_NULL
  *     on failure.
  */

-static thread_t
-choose_thread(
+thread_t
+choose_thread_from_runq(

        processor_t             processor,
        processor_t             processor,

+       run_queue_t             rq,

        int                             priority)
 {
        int                             priority)
 {

-       run_queue_t             rq = &processor->runq;

        queue_t                 queue = rq->queues + rq->highq;
        int                             pri = rq->highq, count = rq->count;
        thread_t                thread;
        queue_t                 queue = rq->queues + rq->highq;
        int                             pri = rq->highq, count = rq->count;
        thread_t                thread;


@@ -1385,11 +2141,12 @@ choose_thread(
                while (!queue_end(queue, (queue_entry_t)thread)) {
                        if (thread->bound_processor == PROCESSOR_NULL ||
                                                        thread->bound_processor == processor) {
                while (!queue_end(queue, (queue_entry_t)thread)) {
                        if (thread->bound_processor == PROCESSOR_NULL ||
                                                        thread->bound_processor == processor) {

-                               remqueue(queue, (queue_entry_t)thread);
+                               remqueue((queue_entry_t)thread);

 
                                thread->runq = PROCESSOR_NULL;
 
                                thread->runq = PROCESSOR_NULL;

+                               SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);

                                rq->count--;
                                rq->count--;

-                               if (testbit(pri, sched_preempt_pri)) {
+                               if (SCHED(priority_is_urgent)(pri)) {

                                        rq->urgency--; assert(rq->urgency >= 0);
                                }
                                if (queue_empty(queue)) {
                                        rq->urgency--; assert(rq->urgency >= 0);
                                }
                                if (queue_empty(queue)) {


@@ -1411,6 +2168,8 @@ choose_thread(
        return (THREAD_NULL);
 }
 
        return (THREAD_NULL);
 }
 

+#endif /* defined(CONFIG_SCHED_TRADITIONAL) */
+

 /*
  *     Perform a context switch and start executing the new thread.
  *
 /*
  *     Perform a context switch and start executing the new thread.
  *


@@ -1419,43 +2178,29 @@ choose_thread(
  *     Called at splsched.
  */
 
  *     Called at splsched.
  */
 

-#define funnel_release_check(thread, debug)                            \
-MACRO_BEGIN                                                                                            \
-       if ((thread)->funnel_state & TH_FN_OWNED) {                     \
-               (thread)->funnel_state = TH_FN_REFUNNEL;                \
-               KERNEL_DEBUG(0x603242c | DBG_FUNC_NONE,                 \
-                       (thread)->funnel_lock, (debug), 0, 0, 0);       \
-               funnel_unlock((thread)->funnel_lock);                   \
-       }                                                                                                       \
-MACRO_END
-
-#define funnel_refunnel_check(thread, debug)                           \
-MACRO_BEGIN                                                                                                    \
-       if ((thread)->funnel_state & TH_FN_REFUNNEL) {                  \
-               kern_return_t   result = (thread)->wait_result;         \
-                                                                                                                       \
-               (thread)->funnel_state = 0;                                                     \
-               KERNEL_DEBUG(0x6032428 | DBG_FUNC_NONE,                         \
-                       (thread)->funnel_lock, (debug), 0, 0, 0);               \
-               funnel_lock((thread)->funnel_lock);                                     \
-               KERNEL_DEBUG(0x6032430 | DBG_FUNC_NONE,                         \
-                       (thread)->funnel_lock, (debug), 0, 0, 0);               \
-               (thread)->funnel_state = TH_FN_OWNED;                           \
-               (thread)->wait_result = result;                                         \
-       }                                                                                                               \
-MACRO_END
-
+/*
+ * thread_invoke
+ *
+ * "self" is what is currently running on the processor,
+ * "thread" is the new thread to context switch to
+ * (which may be the same thread in some cases)
+ */

 static boolean_t
 thread_invoke(
 static boolean_t
 thread_invoke(

-       register thread_t       self,
-       register thread_t       thread,
+       thread_t                        self,
+       thread_t                        thread,

        ast_t                           reason)
 {
        thread_continue_t       continuation = self->continuation;
        ast_t                           reason)
 {
        thread_continue_t       continuation = self->continuation;

-       void                            *parameter = self->parameter;
-       processor_t                     processor;
+       void                    *parameter = self->parameter;
+       processor_t             processor;
+       uint64_t                ctime = mach_absolute_time();
+
+#ifdef CONFIG_MACH_APPROXIMATE_TIME
+       commpage_update_mach_approximate_time(ctime);
+#endif

 
 

-       if (get_preemption_level() != 0) {
+       if (__improbable(get_preemption_level() != 0)) {

                int pl = get_preemption_level();
                panic("thread_invoke: preemption_level %d, possible cause: %s",
                    pl, (pl < 0 ? "unlocking an unlocked mutex or spinlock" :
                int pl = get_preemption_level();
                panic("thread_invoke: preemption_level %d, possible cause: %s",
                    pl, (pl < 0 ? "unlocking an unlocked mutex or spinlock" :


@@ -1463,22 +2208,33 @@ thread_invoke(
        }
 
        assert(self == current_thread());
        }
 
        assert(self == current_thread());

+       assert(self->runq == PROCESSOR_NULL);

 
 

+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+       sched_traditional_consider_maintenance(ctime);
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */       
+       

        /*
         * Mark thread interruptible.
         */
        thread_lock(thread);
        thread->state &= ~TH_UNINT;
 
        /*
         * Mark thread interruptible.
         */
        thread_lock(thread);
        thread->state &= ~TH_UNINT;
 

-#if DEBUG

        assert(thread_runnable(thread));
        assert(thread_runnable(thread));

-#endif
+       assert(thread->bound_processor == PROCESSOR_NULL || thread->bound_processor == current_processor());
+       assert(thread->runq == PROCESSOR_NULL);
+
+       /* Reload precise timing global policy to thread-local policy */
+       thread->precise_user_kernel_time = use_precise_user_kernel_time(thread);
+       
+       /* Update SFI class based on other factors */
+       thread->sfi_class = sfi_thread_classify(thread);

 
        /*
         * Allow time constraint threads to hang onto
         * a stack.
         */
 
        /*
         * Allow time constraint threads to hang onto
         * a stack.
         */

-       if ((self->sched_mode & TH_MODE_REALTIME) && !self->reserved_stack)
+       if ((self->sched_mode == TH_MODE_REALTIME) && !self->reserved_stack)

                self->reserved_stack = self->kernel_stack;
 
        if (continuation != NULL) {
                self->reserved_stack = self->kernel_stack;
 
        if (continuation != NULL) {


@@ -1500,6 +2256,8 @@ thread_invoke(
                        processor = current_processor();
                        processor->active_thread = thread;
                        processor->current_pri = thread->sched_pri;
                        processor = current_processor();
                        processor->active_thread = thread;
                        processor->current_pri = thread->sched_pri;

+                       processor->current_thmode = thread->sched_mode;
+                       processor->current_sfi_class = thread->sfi_class;

                        if (thread->last_processor != processor && thread->last_processor != NULL) {
                                if (thread->last_processor->processor_set != processor->processor_set)
                                        thread->ps_switch++;
                        if (thread->last_processor != processor && thread->last_processor != NULL) {
                                if (thread->last_processor->processor_set != processor->processor_set)
                                        thread->ps_switch++;


@@ -1512,17 +2270,36 @@ thread_invoke(
 
                        self->reason = reason;
 
 
                        self->reason = reason;
 

-                       processor->last_dispatch = mach_absolute_time();
-                       thread_timer_event(processor->last_dispatch, &thread->system_timer);
+                       processor->last_dispatch = ctime;
+                       self->last_run_time = ctime;
+                       thread_timer_event(ctime, &thread->system_timer);

                        PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
                        PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;

+
+                       /*
+                        * Since non-precise user/kernel time doesn't update the state timer
+                        * during privilege transitions, synthesize an event now.
+                        */
+                       if (!thread->precise_user_kernel_time) {
+                               timer_switch(PROCESSOR_DATA(processor, current_state),
+                                                       ctime,
+                                                        PROCESSOR_DATA(processor, current_state));
+                       }

        
        

-                       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_STACK_HANDOFF)|DBG_FUNC_NONE,
-                                                                               self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                               MACHDBG_CODE(DBG_MACH_SCHED, MACH_STACK_HANDOFF)|DBG_FUNC_NONE,
+                               self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+
+                       if ((thread->chosen_processor != processor) && (thread->chosen_processor != PROCESSOR_NULL)) {
+                               KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_MOVED)|DBG_FUNC_NONE,
+                                               (uintptr_t)thread_tid(thread), (uintptr_t)thread->chosen_processor->cpu_id, 0, 0, 0);
+                       }

 
                        DTRACE_SCHED2(off__cpu, struct thread *, thread, struct proc *, thread->task->bsd_info);
 
 
                        DTRACE_SCHED2(off__cpu, struct thread *, thread, struct proc *, thread->task->bsd_info);
 

-                       TLOG(1, "thread_invoke: calling machine_stack_handoff\n");
-                       machine_stack_handoff(self, thread);
+                       SCHED_STATS_CSW(processor, self->reason, self->sched_pri, thread->sched_pri);
+
+                       TLOG(1, "thread_invoke: calling stack_handoff\n");
+                       stack_handoff(self, thread);

 
                        DTRACE_SCHED(on__cpu);
 
 
                        DTRACE_SCHED(on__cpu);
 


@@ -1532,7 +2309,6 @@ thread_invoke(
 
                        counter(c_thread_invoke_hits++);
 
 
                        counter(c_thread_invoke_hits++);
 

-                       funnel_refunnel_check(thread, 2);

                        (void) spllo();
 
                        assert(continuation);
                        (void) spllo();
 
                        assert(continuation);


@@ -1545,9 +2321,12 @@ thread_invoke(
                        counter(++c_thread_invoke_same);
                        thread_unlock(self);
 
                        counter(++c_thread_invoke_same);
                        thread_unlock(self);
 

+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
+                               self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+

                        self->continuation = self->parameter = NULL;
 
                        self->continuation = self->parameter = NULL;
 

-                       funnel_refunnel_check(self, 3);

                        (void) spllo();
 
                        call_continuation(continuation, parameter, self->wait_result);
                        (void) spllo();
 
                        call_continuation(continuation, parameter, self->wait_result);


@@ -1571,6 +2350,11 @@ need_stack:
                        ast_context(self);
                        counter(++c_thread_invoke_same);
                        thread_unlock(self);
                        ast_context(self);
                        counter(++c_thread_invoke_same);
                        thread_unlock(self);

+
+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
+                               self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+

                        return (TRUE);
                }
        }
                        return (TRUE);
                }
        }


@@ -1581,6 +2365,8 @@ need_stack:
        processor = current_processor();
        processor->active_thread = thread;
        processor->current_pri = thread->sched_pri;
        processor = current_processor();
        processor->active_thread = thread;
        processor->current_pri = thread->sched_pri;

+       processor->current_thmode = thread->sched_mode;
+       processor->current_sfi_class = thread->sfi_class;

        if (thread->last_processor != processor && thread->last_processor != NULL) {
                if (thread->last_processor->processor_set != processor->processor_set)
                        thread->ps_switch++;
        if (thread->last_processor != processor && thread->last_processor != NULL) {
                if (thread->last_processor->processor_set != processor->processor_set)
                        thread->ps_switch++;


@@ -1596,21 +2382,42 @@ need_stack:
        assert(self->runq == PROCESSOR_NULL);
        self->reason = reason;
 
        assert(self->runq == PROCESSOR_NULL);
        self->reason = reason;
 

-       processor->last_dispatch = mach_absolute_time();
-       thread_timer_event(processor->last_dispatch, &thread->system_timer);
+       processor->last_dispatch = ctime;
+       self->last_run_time = ctime;
+       thread_timer_event(ctime, &thread->system_timer);

        PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
 
        PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
 

-       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
-                                                       self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+       /*
+        * Since non-precise user/kernel time doesn't update the state timer
+        * during privilege transitions, synthesize an event now.
+        */
+       if (!thread->precise_user_kernel_time) {
+               timer_switch(PROCESSOR_DATA(processor, current_state),
+                                       ctime,
+                                        PROCESSOR_DATA(processor, current_state));
+       }
+       
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
+               self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+
+       if ((thread->chosen_processor != processor) && (thread->chosen_processor != NULL)) {
+               KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_MOVED)|DBG_FUNC_NONE,
+                               (uintptr_t)thread_tid(thread), (uintptr_t)thread->chosen_processor->cpu_id, 0, 0, 0);
+       }

 
        DTRACE_SCHED2(off__cpu, struct thread *, thread, struct proc *, thread->task->bsd_info);
 
 
        DTRACE_SCHED2(off__cpu, struct thread *, thread, struct proc *, thread->task->bsd_info);
 

+       SCHED_STATS_CSW(processor, self->reason, self->sched_pri, thread->sched_pri);
+

        /*
         * This is where we actually switch register context,
         * and address space if required.  We will next run
         * as a result of a subsequent context switch.
         */
        /*
         * This is where we actually switch register context,
         * and address space if required.  We will next run
         * as a result of a subsequent context switch.
         */

+       assert(continuation == self->continuation);

        thread = machine_switch_context(self, continuation, thread);
        thread = machine_switch_context(self, continuation, thread);

+       assert(self == current_thread());

        TLOG(1,"thread_invoke: returning machine_switch_context: self %p continuation %p thread %p\n", self, continuation, thread);
 
        DTRACE_SCHED(on__cpu);
        TLOG(1,"thread_invoke: returning machine_switch_context: self %p continuation %p thread %p\n", self, continuation, thread);
 
        DTRACE_SCHED(on__cpu);


@@ -1623,7 +2430,6 @@ need_stack:
        if (continuation) {
                self->continuation = self->parameter = NULL;
 
        if (continuation) {
                self->continuation = self->parameter = NULL;
 

-               funnel_refunnel_check(self, 3);

                (void) spllo();
 
                call_continuation(continuation, parameter, self->wait_result);
                (void) spllo();
 
                call_continuation(continuation, parameter, self->wait_result);


@@ -1641,6 +2447,9 @@ need_stack:
  *     special actions.  Update quantum for other thread and begin
  *     the quantum for ourselves.
  *
  *     special actions.  Update quantum for other thread and begin
  *     the quantum for ourselves.
  *

+ *     "self" is our new current thread that we have context switched
+ *     to, "thread" is the old thread that we have switched away from.
+ *

  *     Called at splsched.
  */
 void
  *     Called at splsched.
  */
 void


@@ -1659,37 +2468,67 @@ thread_dispatch(
                        stack_free(thread);
 
                if (!(thread->state & TH_IDLE)) {
                        stack_free(thread);
 
                if (!(thread->state & TH_IDLE)) {

+                       int64_t consumed;
+                       int64_t remainder = 0;
+
+                       if (processor->quantum_end > processor->last_dispatch)
+                               remainder = processor->quantum_end -
+                                   processor->last_dispatch;
+
+                       consumed = thread->quantum_remaining - remainder;
+
+                       if ((thread->reason & AST_LEDGER) == 0) {
+                               /*
+                                * Bill CPU time to both the task and
+                                * the individual thread.
+                                */
+                               ledger_credit(thread->t_ledger,
+                                   task_ledgers.cpu_time, consumed);
+                               ledger_credit(thread->t_threadledger,
+                                   thread_ledgers.cpu_time, consumed);
+#ifdef CONFIG_BANK
+                               if (thread->t_bankledger) {
+                                       ledger_credit(thread->t_bankledger,
+                                               bank_ledgers.cpu_time,
+                                               (consumed - thread->t_deduct_bank_ledger_time));
+
+                               }
+                               thread->t_deduct_bank_ledger_time =0;
+#endif
+                       }
+

                        wake_lock(thread);
                        thread_lock(thread);
 
                        /*
                         *      Compute remainder of current quantum.
                         */
                        wake_lock(thread);
                        thread_lock(thread);
 
                        /*
                         *      Compute remainder of current quantum.
                         */

-                       if (    first_timeslice(processor)                                                      &&
-                                       processor->quantum_end > processor->last_dispatch               )
-                               thread->current_quantum = (uint32_t)(processor->quantum_end - processor->last_dispatch);
+                       if (first_timeslice(processor) &&
+                           processor->quantum_end > processor->last_dispatch)
+                               thread->quantum_remaining = (uint32_t)remainder;

                        else
                        else

-                               thread->current_quantum = 0;
+                               thread->quantum_remaining = 0;

 
 

-                       if (thread->sched_mode & TH_MODE_REALTIME) {
+                       if (thread->sched_mode == TH_MODE_REALTIME) {

                                /*
                                 *      Cancel the deadline if the thread has
                                 *      consumed the entire quantum.
                                 */
                                /*
                                 *      Cancel the deadline if the thread has
                                 *      consumed the entire quantum.
                                 */

-                               if (thread->current_quantum == 0) {
+                               if (thread->quantum_remaining == 0) {

                                        thread->realtime.deadline = UINT64_MAX;
                                        thread->realtime.deadline = UINT64_MAX;

-                                       thread->reason |= AST_QUANTUM;

                                }
                        } else {
                                }
                        } else {

+#if defined(CONFIG_SCHED_TRADITIONAL)

                                /*
                                 *      For non-realtime threads treat a tiny
                                 *      remaining quantum as an expired quantum
                                 *      but include what's left next time.
                                 */
                                /*
                                 *      For non-realtime threads treat a tiny
                                 *      remaining quantum as an expired quantum
                                 *      but include what's left next time.
                                 */

-                               if (thread->current_quantum < min_std_quantum) {
+                               if (thread->quantum_remaining < min_std_quantum) {

                                        thread->reason |= AST_QUANTUM;
                                        thread->reason |= AST_QUANTUM;

-                                       thread->current_quantum += std_quantum;
+                                       thread->quantum_remaining += SCHED(initial_quantum_size)(thread);

                                }
                                }

+#endif

                        }
 
                        /*
                        }
 
                        /*


@@ -1697,13 +2536,49 @@ thread_dispatch(
                         *      take the remainder of the quantum.
                         */
                        if ((thread->reason & (AST_HANDOFF|AST_QUANTUM)) == AST_HANDOFF) {
                         *      take the remainder of the quantum.
                         */
                        if ((thread->reason & (AST_HANDOFF|AST_QUANTUM)) == AST_HANDOFF) {

-                               self->current_quantum = thread->current_quantum;
+                               self->quantum_remaining = thread->quantum_remaining;

                                thread->reason |= AST_QUANTUM;
                                thread->reason |= AST_QUANTUM;

-                               thread->current_quantum = 0;
+                               thread->quantum_remaining = 0;
+                       } else {
+#if defined(CONFIG_SCHED_MULTIQ)
+                               if (sched_groups_enabled && thread->sched_group == self->sched_group) {
+                                       /* TODO: Remove tracepoint */
+                                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                           MACHDBG_CODE(DBG_MACH_SCHED, MACH_QUANTUM_HANDOFF) | DBG_FUNC_NONE,
+                                           self->reason, (uintptr_t)thread_tid(thread),
+                                           self->quantum_remaining, thread->quantum_remaining, 0);
+
+                                       self->quantum_remaining = thread->quantum_remaining;
+                                       thread->quantum_remaining = 0;
+                                       /*  TODO: Should we set AST_QUANTUM here? */
+                               }
+#endif /* defined(CONFIG_SCHED_MULTIQ) */

                        }
 
                        thread->computation_metered += (processor->last_dispatch - thread->computation_epoch);
 
                        }
 
                        thread->computation_metered += (processor->last_dispatch - thread->computation_epoch);
 

+                       if ((thread->rwlock_count != 0) && !(LcksOpts & disLkRWPrio)) {
+                               integer_t priority;
+
+                               priority = thread->sched_pri;
+
+                               if (priority < thread->priority)
+                                       priority = thread->priority;
+                               if (priority < BASEPRI_BACKGROUND)
+                                       priority = BASEPRI_BACKGROUND;
+
+                               if ((thread->sched_pri < priority) || !(thread->sched_flags & TH_SFLAG_RW_PROMOTED)) {
+                                       KERNEL_DEBUG_CONSTANT(
+                                               MACHDBG_CODE(DBG_MACH_SCHED, MACH_RW_PROMOTE) | DBG_FUNC_NONE,
+                                               (uintptr_t)thread_tid(thread), thread->sched_pri, thread->priority, priority, 0);
+
+                                       thread->sched_flags |= TH_SFLAG_RW_PROMOTED;
+
+                                       if (thread->sched_pri < priority)
+                                               set_sched_pri(thread, priority);
+                               }
+                       }
+

                        if (!(thread->state & TH_WAIT)) {
                                /*
                                 *      Still running.
                        if (!(thread->state & TH_WAIT)) {
                                /*
                                 *      Still running.


@@ -1718,7 +2593,19 @@ thread_dispatch(
 
                                thread->reason = AST_NONE;
 
 
                                thread->reason = AST_NONE;
 

-                               thread_unlock(thread);
+                               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_DISPATCH) | DBG_FUNC_NONE,
+                                       (uintptr_t)thread_tid(thread), thread->reason, thread->state, sched_run_count, 0);
+                               
+                               if (thread->wake_active) {
+                                       thread->wake_active = FALSE;
+                                       thread_unlock(thread);
+
+                                       thread_wakeup(&thread->wake_active);
+                               }
+                               else
+                                       thread_unlock(thread);
+

                                wake_unlock(thread);
                        }
                        else {
                                wake_unlock(thread);
                        }
                        else {


@@ -1726,6 +2613,7 @@ thread_dispatch(
                                 *      Waiting.
                                 */
                                boolean_t should_terminate = FALSE;
                                 *      Waiting.
                                 */
                                boolean_t should_terminate = FALSE;

+                               uint32_t new_run_count;

 
                                /* Only the first call to thread_dispatch
                                 * after explicit termination should add
 
                                /* Only the first call to thread_dispatch
                                 * after explicit termination should add


@@ -1737,10 +2625,25 @@ thread_dispatch(
                                }
 
                                thread->state &= ~TH_RUN;
                                }
 
                                thread->state &= ~TH_RUN;

+                               thread->chosen_processor = PROCESSOR_NULL;
+
+                               if (thread->sched_mode == TH_MODE_TIMESHARE) {
+                                       if (thread->sched_flags & TH_SFLAG_THROTTLED)
+                                               sched_background_decr(thread);
+
+                                       sched_share_decr(thread);
+                               }
+                               new_run_count = sched_run_decr(thread);

 
 

-                               if (thread->sched_mode & TH_MODE_TIMESHARE)
-                                       sched_share_decr();
-                               sched_run_decr();
+                               if ((thread->state & (TH_WAIT | TH_TERMINATE)) == TH_WAIT) {
+                                       if (thread->reason & AST_SFI) {
+                                               thread->wait_sfi_begin_time = processor->last_dispatch;
+                                       }
+                               }
+
+                               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_DISPATCH) | DBG_FUNC_NONE,
+                                       (uintptr_t)thread_tid(thread), thread->reason, thread->state, new_run_count, 0);

 
                                (*thread->sched_call)(SCHED_CALL_BLOCK, thread);
 
 
                                (*thread->sched_call)(SCHED_CALL_BLOCK, thread);
 


@@ -1762,17 +2665,34 @@ thread_dispatch(
        }
 
        if (!(self->state & TH_IDLE)) {
        }
 
        if (!(self->state & TH_IDLE)) {

+               uint64_t        arg1, arg2;
+               int             urgency;
+               ast_t                   new_ast;
+
+               thread_lock(self);
+               new_ast = sfi_thread_needs_ast(self, NULL);
+               thread_unlock(self);
+
+               if (new_ast != AST_NONE) {
+                       ast_on(new_ast);
+               }
+
+               urgency = thread_get_urgency(self, &arg1, &arg2);
+
+               thread_tell_urgency(urgency, arg1, arg2, self);
+               

                /*
                 *      Get a new quantum if none remaining.
                 */
                /*
                 *      Get a new quantum if none remaining.
                 */

-               if (self->current_quantum == 0)
+               if (self->quantum_remaining == 0) {

                        thread_quantum_init(self);
                        thread_quantum_init(self);

+               }

 
                /*
                 *      Set up quantum timer and timeslice.
                 */
 
                /*
                 *      Set up quantum timer and timeslice.
                 */

-               processor->quantum_end = (processor->last_dispatch + self->current_quantum);
-               timer_call_enter1(&processor->quantum_timer, self, processor->quantum_end);
+               processor->quantum_end = processor->last_dispatch + self->quantum_remaining;
+               timer_call_enter1(&processor->quantum_timer, self, processor->quantum_end, TIMER_CALL_SYS_CRITICAL | TIMER_CALL_LOCAL);

 
                processor->timeslice = 1;
 
 
                processor->timeslice = 1;
 


@@ -1781,14 +2701,11 @@ thread_dispatch(
        else {
                timer_call_cancel(&processor->quantum_timer);
                processor->timeslice = 0;
        else {
                timer_call_cancel(&processor->quantum_timer);
                processor->timeslice = 0;

+
+               thread_tell_urgency(THREAD_URGENCY_NONE, 0, 0, NULL);

        }
 }
 
        }
 }
 

-#include <libkern/OSDebug.h>
-
-uint32_t       kdebug_thread_block = 0;
-
-

 /*
  *     thread_block_reason:
  *
 /*
  *     thread_block_reason:
  *


@@ -1817,9 +2734,6 @@ thread_block_reason(
 
        s = splsched();
 
 
        s = splsched();
 

-       if (!(reason & AST_PREEMPT))
-               funnel_release_check(self, 2);
-

        processor = current_processor();
 
        /* If we're explicitly yielding, force a subsequent quantum */
        processor = current_processor();
 
        /* If we're explicitly yielding, force a subsequent quantum */


@@ -1832,22 +2746,18 @@ thread_block_reason(
        self->continuation = continuation;
        self->parameter = parameter;
 
        self->continuation = continuation;
        self->parameter = parameter;
 

-       if (kdebug_thread_block && kdebug_enable && self->state != TH_RUN) {
-               uint32_t        bt[8];
-
-               OSBacktrace((void **)&bt[0], 8);
-
-               KERNEL_DEBUG_CONSTANT(0x140004c | DBG_FUNC_START, bt[0], bt[1], bt[2], bt[3], 0);
-               KERNEL_DEBUG_CONSTANT(0x140004c | DBG_FUNC_END, bt[4], bt[5], bt[6], bt[7], 0);
+       if (self->state & ~(TH_RUN | TH_IDLE)) {
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_BLOCK), 
+                       reason, VM_KERNEL_UNSLIDE(continuation), 0, 0, 0);

        }
 
        do {
                thread_lock(self);
        }
 
        do {
                thread_lock(self);

-               new_thread = thread_select(self, processor);
+               new_thread = thread_select(self, processor, reason);

                thread_unlock(self);
        } while (!thread_invoke(self, new_thread, reason));
 
                thread_unlock(self);
        } while (!thread_invoke(self, new_thread, reason));
 

-       funnel_refunnel_check(self, 5);

        splx(s);
 
        return (self->wait_result);
        splx(s);
 
        return (self->wait_result);


@@ -1892,8 +2802,6 @@ thread_run(
 {
        ast_t           handoff = AST_HANDOFF;
 
 {
        ast_t           handoff = AST_HANDOFF;
 

-       funnel_release_check(self, 3);
-

        self->continuation = continuation;
        self->parameter = parameter;
 
        self->continuation = continuation;
        self->parameter = parameter;
 


@@ -1901,13 +2809,11 @@ thread_run(
                processor_t             processor = current_processor();
 
                thread_lock(self);
                processor_t             processor = current_processor();
 
                thread_lock(self);

-               new_thread = thread_select(self, processor);
+               new_thread = thread_select(self, processor, AST_NONE);

                thread_unlock(self);
                handoff = AST_NONE;
        }
 
                thread_unlock(self);
                handoff = AST_NONE;
        }
 

-       funnel_refunnel_check(self, 6);
-

        return (self->wait_result);
 }
 
        return (self->wait_result);
 }
 


@@ -1921,9 +2827,9 @@ void
 thread_continue(
        register thread_t       thread)
 {
 thread_continue(
        register thread_t       thread)
 {

-       register thread_t                       self = current_thread();
+       register thread_t               self = current_thread();

        register thread_continue_t      continuation;
        register thread_continue_t      continuation;

-       register void                           *parameter;
+       register void                   *parameter;

 
        DTRACE_SCHED(on__cpu);
 
 
        DTRACE_SCHED(on__cpu);
 


@@ -1934,8 +2840,6 @@ thread_continue(
 
        self->continuation = self->parameter = NULL;
 
 
        self->continuation = self->parameter = NULL;
 

-       funnel_refunnel_check(self, 4);
-

        if (thread != THREAD_NULL)
                (void)spllo();
 
        if (thread != THREAD_NULL)
                (void)spllo();
 


@@ -1944,6 +2848,42 @@ thread_continue(
        /*NOTREACHED*/
 }
 
        /*NOTREACHED*/
 }
 

+void
+thread_quantum_init(thread_t thread)
+{
+       if (thread->sched_mode == TH_MODE_REALTIME) {
+               thread->quantum_remaining = thread->realtime.computation;
+       } else {
+               thread->quantum_remaining = SCHED(initial_quantum_size)(thread);
+       }
+}
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+uint32_t
+sched_traditional_initial_quantum_size(thread_t thread)
+{
+       if ((thread == THREAD_NULL) || !(thread->sched_flags & TH_SFLAG_THROTTLED))
+               return std_quantum;
+       else
+               return bg_quantum;
+}
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static sched_mode_t
+sched_traditional_initial_thread_sched_mode(task_t parent_task)
+{
+       if (parent_task == kernel_task)
+               return TH_MODE_FIXED;
+       else
+               return TH_MODE_TIMESHARE;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+

 /*
  *     run_queue_init:
  *
 /*
  *     run_queue_init:
  *


@@ -1964,16 +2904,97 @@ run_queue_init(
                queue_init(&rq->queues[i]);
 }
 
                queue_init(&rq->queues[i]);
 }
 

+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
+int
+sched_traditional_fairshare_runq_count(void)
+{
+       return fs_runq.count;
+}
+
+uint64_t
+sched_traditional_fairshare_runq_stats_count_sum(void)
+{
+       return fs_runq.runq_stats.count_sum;
+}
+
+void
+sched_traditional_fairshare_enqueue(thread_t thread)
+{
+       queue_t                         queue = &fs_runq.queue;
+       
+       simple_lock(&fs_lock);
+       
+       enqueue_tail(queue, (queue_entry_t)thread);
+       
+       thread->runq = FS_RUNQ;
+       SCHED_STATS_RUNQ_CHANGE(&fs_runq.runq_stats, fs_runq.count);
+       fs_runq.count++;
+       
+       simple_unlock(&fs_lock);        
+}
+
+thread_t
+sched_traditional_fairshare_dequeue(void)
+{
+       thread_t thread;
+       
+       simple_lock(&fs_lock);
+       if (fs_runq.count > 0) {
+               thread = (thread_t)dequeue_head(&fs_runq.queue);
+               
+               thread->runq = PROCESSOR_NULL;
+               SCHED_STATS_RUNQ_CHANGE(&fs_runq.runq_stats, fs_runq.count);
+               fs_runq.count--;
+               
+               simple_unlock(&fs_lock);
+               
+               return (thread);
+       }
+       simple_unlock(&fs_lock);                
+
+       return THREAD_NULL;
+}
+
+boolean_t
+sched_traditional_fairshare_queue_remove(thread_t thread)
+{
+       queue_t                 q;
+
+       simple_lock(&fs_lock);
+       q = &fs_runq.queue;
+       
+       if (FS_RUNQ == thread->runq) {
+               remqueue((queue_entry_t)thread);
+               SCHED_STATS_RUNQ_CHANGE(&fs_runq.runq_stats, fs_runq.count);
+               fs_runq.count--;
+               
+               thread->runq = PROCESSOR_NULL;
+               simple_unlock(&fs_lock);
+               return (TRUE);
+       }
+       else {
+               /*
+                *      The thread left the run queue before we could
+                *      lock the run queue.
+                */
+               assert(thread->runq == PROCESSOR_NULL);
+               simple_unlock(&fs_lock);
+               return (FALSE);
+       }       
+}
+
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
+

 /*
  *     run_queue_dequeue:
  *
  *     Perform a dequeue operation on a run queue,
  *     and return the resulting thread.
  *
 /*
  *     run_queue_dequeue:
  *
  *     Perform a dequeue operation on a run queue,
  *     and return the resulting thread.
  *

- *     The run queue must be locked (see run_queue_remove()
+ *     The run queue must be locked (see thread_run_queue_remove()

  *     for more info), and not empty.
  */
  *     for more info), and not empty.
  */

-static thread_t
+thread_t

 run_queue_dequeue(
        run_queue_t             rq,
        integer_t               options)
 run_queue_dequeue(
        run_queue_t             rq,
        integer_t               options)


@@ -1982,19 +3003,16 @@ run_queue_dequeue(
        queue_t                 queue = rq->queues + rq->highq;
 
        if (options & SCHED_HEADQ) {
        queue_t                 queue = rq->queues + rq->highq;
 
        if (options & SCHED_HEADQ) {

-               thread = (thread_t)queue->next;
-               ((queue_entry_t)thread)->next->prev = queue;
-               queue->next = ((queue_entry_t)thread)->next;
+               thread = (thread_t)dequeue_head(queue);

        }
        else {
        }
        else {

-               thread = (thread_t)queue->prev;
-               ((queue_entry_t)thread)->prev->next = queue;
-               queue->prev = ((queue_entry_t)thread)->prev;
+               thread = (thread_t)dequeue_tail(queue);

        }
 
        thread->runq = PROCESSOR_NULL;
        }
 
        thread->runq = PROCESSOR_NULL;

+       SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);

        rq->count--;
        rq->count--;

-       if (testbit(rq->highq, sched_preempt_pri)) {
+       if (SCHED(priority_is_urgent)(rq->highq)) {

                rq->urgency--; assert(rq->urgency >= 0);
        }
        if (queue_empty(queue)) {
                rq->urgency--; assert(rq->urgency >= 0);
        }
        if (queue_empty(queue)) {


@@ -2006,6 +3024,103 @@ run_queue_dequeue(
        return (thread);
 }
 
        return (thread);
 }
 

+/*
+ *     run_queue_enqueue:
+ *
+ *     Perform a enqueue operation on a run queue.
+ *
+ *     The run queue must be locked (see thread_run_queue_remove()
+ *     for more info).
+ */
+boolean_t
+run_queue_enqueue(
+                                                         run_queue_t           rq,
+                                                         thread_t                      thread,
+                                                         integer_t             options)
+{
+       queue_t                 queue = rq->queues + thread->sched_pri;
+       boolean_t               result = FALSE;
+       
+       if (queue_empty(queue)) {
+               enqueue_tail(queue, (queue_entry_t)thread);
+               
+               setbit(MAXPRI - thread->sched_pri, rq->bitmap);
+               if (thread->sched_pri > rq->highq) {
+                       rq->highq = thread->sched_pri;
+                       result = TRUE;
+               }
+       } else {
+               if (options & SCHED_TAILQ)
+                       enqueue_tail(queue, (queue_entry_t)thread);
+               else
+                       enqueue_head(queue, (queue_entry_t)thread);
+       }
+       if (SCHED(priority_is_urgent)(thread->sched_pri))
+               rq->urgency++;
+       SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+       rq->count++;
+       
+       return (result);
+       
+}
+
+/*
+ *     run_queue_remove:
+ *
+ *     Remove a specific thread from a runqueue.
+ *
+ *     The run queue must be locked.
+ */
+void
+run_queue_remove(
+                                 run_queue_t           rq,
+                                 thread_t                      thread)
+{
+
+       remqueue((queue_entry_t)thread);
+       SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+       rq->count--;
+       if (SCHED(priority_is_urgent)(thread->sched_pri)) {
+               rq->urgency--; assert(rq->urgency >= 0);
+       }
+       
+       if (queue_empty(rq->queues + thread->sched_pri)) {
+               /* update run queue status */
+               if (thread->sched_pri != IDLEPRI)
+                       clrbit(MAXPRI - thread->sched_pri, rq->bitmap);
+               rq->highq = MAXPRI - ffsbit(rq->bitmap);
+       }
+       
+       thread->runq = PROCESSOR_NULL;
+}
+
+/*
+ *     fairshare_setrun:
+ *
+ *     Dispatch a thread for round-robin execution.
+ *
+ *     Thread must be locked.  Associated pset must
+ *     be locked, and is returned unlocked.
+ */
+static void
+fairshare_setrun(
+                                 processor_t                   processor,
+                                 thread_t                      thread)
+{
+       processor_set_t         pset = processor->processor_set;
+               
+       thread->chosen_processor = processor;
+
+       SCHED(fairshare_enqueue)(thread);
+       
+       pset_unlock(pset);
+
+       if (processor != current_processor())
+               machine_signal_idle(processor);
+
+
+}
+

 /*
  *     realtime_queue_insert:
  *
 /*
  *     realtime_queue_insert:
  *


@@ -2015,8 +3130,7 @@ static boolean_t
 realtime_queue_insert(
        thread_t                        thread)
 {
 realtime_queue_insert(
        thread_t                        thread)
 {

-       run_queue_t                     rq = &rt_runq;
-       queue_t                         queue = rq->queues + thread->sched_pri;
+       queue_t                         queue = &rt_runq.queue;

        uint64_t                        deadline = thread->realtime.deadline;
        boolean_t                       preempt = FALSE;
 
        uint64_t                        deadline = thread->realtime.deadline;
        boolean_t                       preempt = FALSE;
 


@@ -2024,10 +3138,6 @@ realtime_queue_insert(
 
        if (queue_empty(queue)) {
                enqueue_tail(queue, (queue_entry_t)thread);
 
        if (queue_empty(queue)) {
                enqueue_tail(queue, (queue_entry_t)thread);

-
-               setbit(MAXPRI - thread->sched_pri, rq->bitmap);
-               if (thread->sched_pri > rq->highq)
-                       rq->highq = thread->sched_pri;

                preempt = TRUE;
        }
        else {
                preempt = TRUE;
        }
        else {


@@ -2050,7 +3160,8 @@ realtime_queue_insert(
        }
 
        thread->runq = RT_RUNQ;
        }
 
        thread->runq = RT_RUNQ;

-       rq->count++; rq->urgency++;
+       SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+       rt_runq.count++;

 
        simple_unlock(&rt_lock);
 
 
        simple_unlock(&rt_lock);
 


@@ -2071,34 +3182,116 @@ realtime_setrun(
        thread_t                        thread)
 {
        processor_set_t         pset = processor->processor_set;
        thread_t                        thread)
 {
        processor_set_t         pset = processor->processor_set;

+       ast_t                           preempt;
+
+       boolean_t do_signal_idle = FALSE, do_cause_ast = FALSE;
+
+       thread->chosen_processor = processor;
+
+       /* <rdar://problem/15102234> */
+       assert(thread->bound_processor == PROCESSOR_NULL);

 
        /*
         *      Dispatch directly onto idle processor.
         */
 
        /*
         *      Dispatch directly onto idle processor.
         */

-       if (processor->state == PROCESSOR_IDLE) {
-               remqueue(&pset->idle_queue, (queue_entry_t)processor);
+       if ( (thread->bound_processor == processor)
+               && processor->state == PROCESSOR_IDLE) {
+               remqueue((queue_entry_t)processor);

                enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
 
                enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
 

-               processor->next_thread = thread;
-               processor->deadline = thread->realtime.deadline;
-               processor->state = PROCESSOR_DISPATCHING;
-               pset_unlock(pset);
+               processor->next_thread = thread;
+               processor->current_pri = thread->sched_pri;
+               processor->current_thmode = thread->sched_mode;
+               processor->current_sfi_class = thread->sfi_class;
+               processor->deadline = thread->realtime.deadline;
+               processor->state = PROCESSOR_DISPATCHING;
+
+               if (processor != current_processor()) {
+                       if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+                               /* cleared on exit from main processor_idle() loop */
+                               pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+                               do_signal_idle = TRUE;
+                       }
+               }
+               pset_unlock(pset);
+
+               if (do_signal_idle) {
+                       machine_signal_idle(processor);
+               }
+               return;
+       }
+
+       if (processor->current_pri < BASEPRI_RTQUEUES)
+               preempt = (AST_PREEMPT | AST_URGENT);
+       else if (thread->realtime.deadline < processor->deadline)
+               preempt = (AST_PREEMPT | AST_URGENT);
+       else
+               preempt = AST_NONE;
+
+       realtime_queue_insert(thread);
+
+       if (preempt != AST_NONE) {
+               if (processor->state == PROCESSOR_IDLE) {
+                       remqueue((queue_entry_t)processor);
+                       enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+                       processor->next_thread = THREAD_NULL;
+                       processor->current_pri = thread->sched_pri;
+                       processor->current_thmode = thread->sched_mode;
+                       processor->current_sfi_class = thread->sfi_class;
+                       processor->deadline = thread->realtime.deadline;
+                       processor->state = PROCESSOR_DISPATCHING;
+                       if (processor == current_processor()) {
+                               ast_on(preempt);
+                       } else {
+                               if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+                                       /* cleared on exit from main processor_idle() loop */
+                                       pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+                                       do_signal_idle = TRUE;
+                               }
+                       }
+               } else if (processor->state == PROCESSOR_DISPATCHING) {
+                       if ((processor->next_thread == THREAD_NULL) && ((processor->current_pri < thread->sched_pri) || (processor->deadline > thread->realtime.deadline))) {
+                               processor->current_pri = thread->sched_pri;
+                               processor->current_thmode = thread->sched_mode;
+                               processor->current_sfi_class = thread->sfi_class;
+                               processor->deadline = thread->realtime.deadline;
+                       }
+               } else {
+                       if (processor == current_processor()) {
+                               ast_on(preempt);
+                       } else {
+                               if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+                                       /* cleared after IPI causes csw_check() to be called */
+                                       pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+                                       do_cause_ast = TRUE;
+                               }
+                       }
+               }
+       } else {
+               /* Selected processor was too busy, just keep thread enqueued and let other processors drain it naturally. */
+       }
+
+       pset_unlock(pset);

 
 

-               if (processor != current_processor())
-                       machine_signal_idle(processor);
-               return;
+       if (do_signal_idle) {
+               machine_signal_idle(processor);
+       } else if (do_cause_ast) {
+               cause_ast_check(processor);

        }
        }

+}

 
 

-       if (realtime_queue_insert(thread)) {
-               if (processor == current_processor())
-                       ast_on(AST_PREEMPT | AST_URGENT);
-               else
-                       cause_ast_check(processor);
-       }

 
 

-       pset_unlock(pset);
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+boolean_t
+priority_is_urgent(int priority)
+{
+       return testbit(priority, sched_preempt_pri) ? TRUE : FALSE;

 }
 
 }
 

+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)

 /*
  *     processor_enqueue:
  *
 /*
  *     processor_enqueue:
  *


@@ -2108,7 +3301,7 @@ realtime_setrun(
  *     Returns TRUE if a preemption is indicated based on the state
  *     of the run queue.
  *
  *     Returns TRUE if a preemption is indicated based on the state
  *     of the run queue.
  *

- *     The run queue must be locked (see run_queue_remove()
+ *     The run queue must be locked (see thread_run_queue_remove()

  *     for more info).
  */
 static boolean_t
  *     for more info).
  */
 static boolean_t


@@ -2117,33 +3310,18 @@ processor_enqueue(
        thread_t                thread,
        integer_t               options)
 {
        thread_t                thread,
        integer_t               options)
 {

-       run_queue_t             rq = &processor->runq;
-       queue_t                 queue = rq->queues + thread->sched_pri;
-       boolean_t               result = FALSE;
+       run_queue_t             rq = runq_for_processor(processor);
+       boolean_t               result;

        
        

-       if (queue_empty(queue)) {
-               enqueue_tail(queue, (queue_entry_t)thread);
-
-               setbit(MAXPRI - thread->sched_pri, rq->bitmap);
-               if (thread->sched_pri > rq->highq) {
-                       rq->highq = thread->sched_pri;
-                       result = TRUE;
-               }
-       }
-       else
-       if (options & SCHED_TAILQ)
-               enqueue_tail(queue, (queue_entry_t)thread);
-       else
-               enqueue_head(queue, (queue_entry_t)thread);
-
+       result = run_queue_enqueue(rq, thread, options);

        thread->runq = processor;
        thread->runq = processor;

-       if (testbit(thread->sched_pri, sched_preempt_pri))
-               rq->urgency++;
-       rq->count++;
+       runq_consider_incr_bound_count(processor, thread);

 
        return (result);
 }
 
 
        return (result);
 }
 

+#endif /* CONFIG_SCHED_TRADITIONAL */
+

 /*
  *     processor_setrun:
  *
 /*
  *     processor_setrun:
  *


@@ -2161,60 +3339,252 @@ processor_setrun(
 {
        processor_set_t         pset = processor->processor_set;
        ast_t                           preempt;
 {
        processor_set_t         pset = processor->processor_set;
        ast_t                           preempt;

+       enum { eExitIdle, eInterruptRunning, eDoNothing } ipi_action = eDoNothing;
+
+       boolean_t do_signal_idle = FALSE, do_cause_ast = FALSE;
+
+       thread->chosen_processor = processor;

 
        /*
         *      Dispatch directly onto idle processor.
         */
 
        /*
         *      Dispatch directly onto idle processor.
         */

-       if (processor->state == PROCESSOR_IDLE) {
-               remqueue(&pset->idle_queue, (queue_entry_t)processor);
+       if ( (SCHED(direct_dispatch_to_idle_processors) ||
+                 thread->bound_processor == processor)
+               && processor->state == PROCESSOR_IDLE) {
+               remqueue((queue_entry_t)processor);

                enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
 
                processor->next_thread = thread;
                enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
 
                processor->next_thread = thread;

+               processor->current_pri = thread->sched_pri;
+               processor->current_thmode = thread->sched_mode;
+               processor->current_sfi_class = thread->sfi_class;

                processor->deadline = UINT64_MAX;
                processor->state = PROCESSOR_DISPATCHING;
                processor->deadline = UINT64_MAX;
                processor->state = PROCESSOR_DISPATCHING;

-               pset_unlock(pset);

 
 

-               if (processor != current_processor())
+               if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+                       /* cleared on exit from main processor_idle() loop */
+                       pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+                       do_signal_idle = TRUE;
+               }
+
+               pset_unlock(pset);
+               if (do_signal_idle) {

                        machine_signal_idle(processor);
                        machine_signal_idle(processor);

+               }
+

                return;
        }
 
        /*
         *      Set preemption mode.
         */
                return;
        }
 
        /*
         *      Set preemption mode.
         */

-       if (testbit(thread->sched_pri, sched_preempt_pri))
+       if (SCHED(priority_is_urgent)(thread->sched_pri) && thread->sched_pri > processor->current_pri)

                preempt = (AST_PREEMPT | AST_URGENT);
                preempt = (AST_PREEMPT | AST_URGENT);

-       else
-       if (thread->sched_mode & TH_MODE_TIMESHARE && thread->sched_pri < thread->priority)
-               preempt = AST_NONE;
-       else
+       else if(processor->active_thread && thread_eager_preemption(processor->active_thread))
+               preempt = (AST_PREEMPT | AST_URGENT);
+       else if ((thread->sched_mode == TH_MODE_TIMESHARE) && (thread->sched_pri < thread->priority)) {
+               if(SCHED(priority_is_urgent)(thread->priority) && thread->sched_pri > processor->current_pri) {
+                       preempt = (options & SCHED_PREEMPT)? AST_PREEMPT: AST_NONE;
+               } else {
+                       preempt = AST_NONE;
+               }
+       } else

                preempt = (options & SCHED_PREEMPT)? AST_PREEMPT: AST_NONE;
 
                preempt = (options & SCHED_PREEMPT)? AST_PREEMPT: AST_NONE;
 

-       if (!processor_enqueue(processor, thread, options))
-               preempt = AST_NONE;
+       SCHED(processor_enqueue)(processor, thread, options);

 
        if (preempt != AST_NONE) {
 
        if (preempt != AST_NONE) {

-               if (processor == current_processor()) {
-                       if (csw_check(processor) != AST_NONE)
-                               ast_on(preempt);
-               }
-               else
-               if (    (processor->state == PROCESSOR_RUNNING          ||
+               if (processor->state == PROCESSOR_IDLE) {
+                       remqueue((queue_entry_t)processor);
+                       enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+                       processor->next_thread = THREAD_NULL;
+                       processor->current_pri = thread->sched_pri;
+                       processor->current_thmode = thread->sched_mode;
+                       processor->current_sfi_class = thread->sfi_class;
+                       processor->deadline = UINT64_MAX;
+                       processor->state = PROCESSOR_DISPATCHING;
+
+                       ipi_action = eExitIdle;
+               } else if ( processor->state == PROCESSOR_DISPATCHING) {
+                       if ((processor->next_thread == THREAD_NULL) && (processor->current_pri < thread->sched_pri)) {
+                               processor->current_pri = thread->sched_pri;
+                               processor->current_thmode = thread->sched_mode;
+                               processor->current_sfi_class = thread->sfi_class;
+                               processor->deadline = UINT64_MAX;
+                       }
+               } else if (     (processor->state == PROCESSOR_RUNNING          ||

                                 processor->state == PROCESSOR_SHUTDOWN)                &&
                                 processor->state == PROCESSOR_SHUTDOWN)                &&

-                               thread->sched_pri >= processor->current_pri             ) {
-                       cause_ast_check(processor);
+                               (thread->sched_pri >= processor->current_pri    ||
+                               processor->current_thmode == TH_MODE_FAIRSHARE)) {
+                       ipi_action = eInterruptRunning;

                }
                }

-       }
-       else
-       if (    processor->state == PROCESSOR_SHUTDOWN          &&
+       } else {
+               /*
+                * New thread is not important enough to preempt what is running, but
+                * special processor states may need special handling
+                */
+               if (processor->state == PROCESSOR_SHUTDOWN              &&

                        thread->sched_pri >= processor->current_pri     ) {
                        thread->sched_pri >= processor->current_pri     ) {

-               cause_ast_check(processor);
+                       ipi_action = eInterruptRunning;
+               } else if (     processor->state == PROCESSOR_IDLE      &&
+                                       processor != current_processor()        ) {
+                       remqueue((queue_entry_t)processor);
+                       enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+                       processor->next_thread = THREAD_NULL;
+                       processor->current_pri = thread->sched_pri;
+                       processor->current_thmode = thread->sched_mode;
+                       processor->current_sfi_class = thread->sfi_class;
+                       processor->deadline = UINT64_MAX;
+                       processor->state = PROCESSOR_DISPATCHING;
+
+                       ipi_action = eExitIdle;
+               }
+       }
+
+       switch (ipi_action) {
+               case eDoNothing:
+                       break;
+               case eExitIdle:
+                       if (processor == current_processor()) {
+                               if (csw_check_locked(processor, pset, AST_NONE) != AST_NONE)
+                                       ast_on(preempt);
+                       } else {
+                               if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+                                       /* cleared on exit from main processor_idle() loop */
+                                       pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+                                       do_signal_idle = TRUE;
+                               }
+                       }
+                       break;
+               case eInterruptRunning:
+                       if (processor == current_processor()) {
+                               if (csw_check_locked(processor, pset, AST_NONE) != AST_NONE)
+                                       ast_on(preempt);
+                       } else {
+                               if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+                                       /* cleared after IPI causes csw_check() to be called */
+                                       pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+                                       do_cause_ast = TRUE;
+                               }
+                       }
+                       break;

        }
 
        pset_unlock(pset);
        }
 
        pset_unlock(pset);

+
+       if (do_signal_idle) {
+               machine_signal_idle(processor);
+       } else if (do_cause_ast) {
+               cause_ast_check(processor);
+       }
+}
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static boolean_t
+processor_queue_empty(processor_t              processor)
+{
+       return runq_for_processor(processor)->count == 0;
+       
+}
+
+static boolean_t
+sched_traditional_with_pset_runqueue_processor_queue_empty(processor_t         processor)
+{
+       processor_set_t pset = processor->processor_set;
+       int count = runq_for_processor(processor)->count;
+
+       /*
+        * The pset runq contains the count of all runnable threads
+        * for all processors in the pset. However, for threads that
+        * are bound to another processor, the current "processor"
+        * is not eligible to execute the thread. So we only
+        * include bound threads that our bound to the current
+        * "processor". This allows the processor to idle when the
+        * count of eligible threads drops to 0, even if there's
+        * a runnable thread bound to a different processor in the
+        * shared runq.
+        */
+
+       count -= pset->pset_runq_bound_count;
+       count += processor->runq_bound_count;
+
+       return count == 0;
+}
+
+static ast_t
+processor_csw_check(processor_t processor)
+{
+       run_queue_t             runq;
+       boolean_t               has_higher;
+
+       assert(processor->active_thread != NULL);
+       
+       runq = runq_for_processor(processor);
+       if (first_timeslice(processor)) {
+               has_higher = (runq->highq > processor->current_pri);
+       } else {
+               has_higher = (runq->highq >= processor->current_pri);
+       }
+       if (has_higher) {
+               if (runq->urgency > 0)
+                       return (AST_PREEMPT | AST_URGENT);
+               
+               if (processor->active_thread && thread_eager_preemption(processor->active_thread))
+                       return (AST_PREEMPT | AST_URGENT);
+
+               return AST_PREEMPT;
+       }
+
+       return AST_NONE;
+}
+
+static boolean_t
+processor_queue_has_priority(processor_t               processor,
+                                                        int                            priority,
+                                                        boolean_t                      gte)
+{
+       if (gte)
+               return runq_for_processor(processor)->highq >= priority;
+       else
+               return runq_for_processor(processor)->highq > priority;

 }
 
 }
 

-#define next_pset(p)   (((p)->pset_list != PROCESSOR_SET_NULL)? (p)->pset_list: (p)->node->psets)
+static boolean_t
+should_current_thread_rechoose_processor(processor_t                   processor)
+{
+       return (processor->current_pri < BASEPRI_RTQUEUES
+                       && processor->processor_primary != processor);
+}
+
+static int
+sched_traditional_processor_runq_count(processor_t   processor)
+{
+       return runq_for_processor(processor)->count;
+}
+
+static uint64_t
+sched_traditional_processor_runq_stats_count_sum(processor_t   processor)
+{
+       return runq_for_processor(processor)->runq_stats.count_sum;
+}
+
+static uint64_t
+sched_traditional_with_pset_runqueue_processor_runq_stats_count_sum(processor_t   processor)
+{
+       if (processor->cpu_id == processor->processor_set->cpu_set_low)
+               return runq_for_processor(processor)->runq_stats.count_sum;
+       else
+               return 0ULL;
+}
+
+static int
+sched_traditional_processor_bound_count(processor_t   processor)
+{
+       return processor->runq_bound_count;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */

 
 /*
  *     choose_next_pset:
 
 /*
  *     choose_next_pset:


@@ -2233,7 +3603,7 @@ choose_next_pset(
 
        do {
                nset = next_pset(nset);
 
        do {
                nset = next_pset(nset);

-       } while (nset->processor_count < 1 && nset != pset);
+       } while (nset->online_processor_count < 1 && nset != pset);

 
        return (nset);
 }
 
        return (nset);
 }


@@ -2250,152 +3620,235 @@ choose_next_pset(
  *     The thread must be locked.  The pset must be locked,
  *     and the resulting pset is locked on return.
  */
  *     The thread must be locked.  The pset must be locked,
  *     and the resulting pset is locked on return.
  */

-static processor_t
+processor_t

 choose_processor(
        processor_set_t         pset,
        processor_t                     processor,
        thread_t                        thread)
 {
        processor_set_t         nset, cset = pset;
 choose_processor(
        processor_set_t         pset,
        processor_t                     processor,
        thread_t                        thread)
 {
        processor_set_t         nset, cset = pset;

-       processor_meta_t        pmeta = PROCESSOR_META_NULL;
-       processor_t             mprocessor;

        
        /*
        
        /*

-        *      Prefer the hinted processor, when appropriate.
+        * Prefer the hinted processor, when appropriate.

         */
 
         */
 

+       /* Fold last processor hint from secondary processor to its primary */

        if (processor != PROCESSOR_NULL) {
        if (processor != PROCESSOR_NULL) {

-               if (processor->processor_meta != PROCESSOR_META_NULL)
-                       processor = processor->processor_meta->primary;
+               processor = processor->processor_primary;

        }
 
        }
 

-       mprocessor = machine_choose_processor(pset, processor);
-       if (mprocessor != PROCESSOR_NULL)
-               processor = mprocessor;
+       /*
+        * Only consult platform layer if pset is active, which
+        * it may not be in some cases when a multi-set system
+        * is going to sleep.
+        */
+       if (pset->online_processor_count) {
+               if ((processor == PROCESSOR_NULL) || (processor->processor_set == pset && processor->state == PROCESSOR_IDLE)) {
+                       processor_t mc_processor = machine_choose_processor(pset, processor);
+                       if (mc_processor != PROCESSOR_NULL)
+                               processor = mc_processor->processor_primary;
+               }
+       }

 
 

+       /*
+        * At this point, we may have a processor hint, and we may have
+        * an initial starting pset. If the hint is not in the pset, or
+        * if the hint is for a processor in an invalid state, discard
+        * the hint.
+        */

        if (processor != PROCESSOR_NULL) {
        if (processor != PROCESSOR_NULL) {

-               if (processor->processor_set != pset ||
-                   processor->state == PROCESSOR_INACTIVE ||
-                   processor->state == PROCESSOR_SHUTDOWN ||
-                   processor->state == PROCESSOR_OFF_LINE)
+               if (processor->processor_set != pset) {

                        processor = PROCESSOR_NULL;
                        processor = PROCESSOR_NULL;

-               else
-                       if (processor->state == PROCESSOR_IDLE ||
-                           ((thread->sched_pri >= BASEPRI_RTQUEUES) &&
-                           (processor->current_pri < BASEPRI_RTQUEUES)))
-                               return (processor);
+               } else {
+                       switch (processor->state) {
+                               case PROCESSOR_START:
+                               case PROCESSOR_SHUTDOWN:
+                               case PROCESSOR_OFF_LINE:
+                                       /*
+                                        * Hint is for a processor that cannot support running new threads.
+                                        */
+                                       processor = PROCESSOR_NULL;
+                                       break;
+                               case PROCESSOR_IDLE:
+                                       /*
+                                        * Hint is for an idle processor. Assume it is no worse than any other
+                                        * idle processor. The platform layer had an opportunity to provide
+                                        * the "least cost idle" processor above.
+                                        */
+                                       return (processor);
+                                       break;
+                               case PROCESSOR_RUNNING:
+                               case PROCESSOR_DISPATCHING:
+                                       /*
+                                        * Hint is for an active CPU. This fast-path allows
+                                        * realtime threads to preempt non-realtime threads
+                                        * to regain their previous executing processor.
+                                        */
+                                       if ((thread->sched_pri >= BASEPRI_RTQUEUES) &&
+                                               (processor->current_pri < BASEPRI_RTQUEUES))
+                                               return (processor);
+
+                                       /* Otherwise, use hint as part of search below */
+                                       break;
+                               default:
+                                       processor = PROCESSOR_NULL;
+                                       break;
+                       }
+               }

        }
 
        /*
        }
 
        /*

-        *      Iterate through the processor sets to locate
-        *      an appropriate processor.
+        * Iterate through the processor sets to locate
+        * an appropriate processor. Seed results with
+        * a last-processor hint, if available, so that
+        * a search must find something strictly better
+        * to replace it.
+        *
+        * A primary/secondary pair of SMT processors are
+        * "unpaired" if the primary is busy but its
+        * corresponding secondary is idle (so the physical
+        * core has full use of its resources).

         */
         */

+
+       integer_t lowest_priority = MAXPRI + 1;
+       integer_t lowest_unpaired_primary_priority = MAXPRI + 1;
+       integer_t lowest_count = INT_MAX;
+       uint64_t  furthest_deadline = 1;
+       processor_t lp_processor = PROCESSOR_NULL;
+       processor_t lp_unpaired_primary_processor = PROCESSOR_NULL;
+       processor_t lp_unpaired_secondary_processor = PROCESSOR_NULL;
+       processor_t lc_processor = PROCESSOR_NULL;
+       processor_t fd_processor = PROCESSOR_NULL;
+
+       if (processor != PROCESSOR_NULL) {
+               /* All other states should be enumerated above. */
+               assert(processor->state == PROCESSOR_RUNNING || processor->state == PROCESSOR_DISPATCHING);
+
+               lowest_priority = processor->current_pri;
+               lp_processor = processor;
+
+               if (processor->current_pri >= BASEPRI_RTQUEUES) {
+                       furthest_deadline = processor->deadline;
+                       fd_processor = processor;
+               }
+
+               lowest_count = SCHED(processor_runq_count)(processor);
+               lc_processor = processor;
+       }
+

        do {
        do {

+

                /*
                /*

-                *      Choose an idle processor.
+                * Choose an idle processor, in pset traversal order

                 */
                if (!queue_empty(&cset->idle_queue))
                        return ((processor_t)queue_first(&cset->idle_queue));
 
                 */
                if (!queue_empty(&cset->idle_queue))
                        return ((processor_t)queue_first(&cset->idle_queue));
 

-               if (thread->sched_pri >= BASEPRI_RTQUEUES) {
-                       integer_t lowest_priority = MAXPRI + 1;
-                       integer_t lowest_unpaired = MAXPRI + 1;
-                       uint64_t  furthest_deadline = 1;
-                       processor_t lp_processor = PROCESSOR_NULL;
-                       processor_t lp_unpaired = PROCESSOR_NULL;
-                       processor_t fd_processor = PROCESSOR_NULL;
-
-                       lp_processor = cset->low_pri;
-                       /* Consider hinted processor */
-                       if (lp_processor != PROCESSOR_NULL &&
-                       ((lp_processor->processor_meta == PROCESSOR_META_NULL) ||
-                       ((lp_processor == lp_processor->processor_meta->primary) &&
-                           !queue_empty(&lp_processor->processor_meta->idle_queue))) &&
-                           lp_processor->state != PROCESSOR_INACTIVE &&
-                           lp_processor->state != PROCESSOR_SHUTDOWN &&
-                           lp_processor->state != PROCESSOR_OFF_LINE &&
-                           (lp_processor->current_pri < thread->sched_pri))
-                               return lp_processor;
+               /*
+                * Otherwise, enumerate active and idle processors to find candidates
+                * with lower priority/etc.
+                */

 
 

-                       processor = (processor_t)queue_first(&cset->active_queue);
-                       while (!queue_end(&cset->active_queue, (queue_entry_t)processor)) {
-                               /* Discover the processor executing the
-                                * thread with the lowest priority within
-                                * this pset, or the one with the furthest
-                                * deadline
-                                */
-                               integer_t cpri = processor->current_pri;
-                               if (cpri < lowest_priority) {
-                                       lowest_priority = cpri;
-                                       lp_processor = processor;
-                               }
+               processor = (processor_t)queue_first(&cset->active_queue);
+               while (!queue_end(&cset->active_queue, (queue_entry_t)processor)) {

 
 

-                               if ((cpri >= BASEPRI_RTQUEUES) && (processor->deadline > furthest_deadline)) {
-                                       furthest_deadline = processor->deadline;
-                                       fd_processor = processor;
-                               }
+                       integer_t cpri = processor->current_pri;
+                       if (cpri < lowest_priority) {
+                               lowest_priority = cpri;
+                               lp_processor = processor;
+                       }

 
 

+                       if ((cpri >= BASEPRI_RTQUEUES) && (processor->deadline > furthest_deadline)) {
+                               furthest_deadline = processor->deadline;
+                               fd_processor = processor;
+                       }

 
 

-                               if (processor->processor_meta != PROCESSOR_META_NULL &&
-                                   !queue_empty(&processor->processor_meta->idle_queue)) {
-                                       if (cpri < lowest_unpaired) {
-                                               lowest_unpaired = cpri;
-                                               lp_unpaired = processor;
-                                               pmeta = processor->processor_meta;
-                                       }
-                                       else
-                                               if (pmeta == PROCESSOR_META_NULL)
-                                                       pmeta = processor->processor_meta;
+                       integer_t ccount = SCHED(processor_runq_count)(processor);
+                       if (ccount < lowest_count) {
+                               lowest_count = ccount;
+                               lc_processor = processor;
+                       }
+
+                       processor = (processor_t)queue_next((queue_entry_t)processor);
+               }
+
+               /*
+                * For SMT configs, these idle secondary processors must have active primary. Otherwise
+                * the idle primary would have short-circuited the loop above
+                */
+               processor = (processor_t)queue_first(&cset->idle_secondary_queue);
+               while (!queue_end(&cset->idle_secondary_queue, (queue_entry_t)processor)) {
+                       processor_t cprimary = processor->processor_primary;
+
+                       /* If the primary processor is offline or starting up, it's not a candidate for this path */
+                       if (cprimary->state == PROCESSOR_RUNNING || cprimary->state == PROCESSOR_DISPATCHING) {
+                               integer_t primary_pri = cprimary->current_pri;
+
+                               if (primary_pri < lowest_unpaired_primary_priority) {
+                                       lowest_unpaired_primary_priority = primary_pri;
+                                       lp_unpaired_primary_processor = cprimary;
+                                       lp_unpaired_secondary_processor = processor;

                                }
                                }

-                               processor = (processor_t)queue_next((queue_entry_t)processor);

                        }
 
                        }
 

-                       if (thread->sched_pri > lowest_unpaired)
-                               return lp_unpaired;
+                       processor = (processor_t)queue_next((queue_entry_t)processor);
+               }
+

 
 

-                       if (pmeta != PROCESSOR_META_NULL)
-                               return ((processor_t)queue_first(&pmeta->idle_queue));
-                       if (thread->sched_pri > lowest_priority)
+               if (thread->sched_pri >= BASEPRI_RTQUEUES) {
+
+                       /*
+                        * For realtime threads, the most important aspect is
+                        * scheduling latency, so we attempt to assign threads
+                        * to good preemption candidates (assuming an idle primary
+                        * processor was not available above).
+                        */
+
+                       if (thread->sched_pri > lowest_unpaired_primary_priority) {
+                               /* Move to end of active queue so that the next thread doesn't also pick it */
+                               remqueue((queue_entry_t)lp_unpaired_primary_processor);
+                               enqueue_tail(&cset->active_queue, (queue_entry_t)lp_unpaired_primary_processor);
+                               return lp_unpaired_primary_processor;
+                       }
+                       if (thread->sched_pri > lowest_priority) {
+                               /* Move to end of active queue so that the next thread doesn't also pick it */
+                               remqueue((queue_entry_t)lp_processor);
+                               enqueue_tail(&cset->active_queue, (queue_entry_t)lp_processor);

                                return lp_processor;
                                return lp_processor;

+                       }

                        if (thread->realtime.deadline < furthest_deadline)
                                return fd_processor;
                        if (thread->realtime.deadline < furthest_deadline)
                                return fd_processor;

-                       processor = PROCESSOR_NULL;
-               }
-               else {
+

                        /*
                        /*

-                        *      Check any hinted processors in the processor set if available.
+                        * If all primary and secondary CPUs are busy with realtime
+                        * threads with deadlines earlier than us, move on to next
+                        * pset.

                         */
                         */

-                       if (cset->low_pri != PROCESSOR_NULL && cset->low_pri->state != PROCESSOR_INACTIVE &&
-                                       cset->low_pri->state != PROCESSOR_SHUTDOWN && cset->low_pri->state != PROCESSOR_OFF_LINE &&
-                                               (processor == PROCESSOR_NULL ||
-                                                       (thread->sched_pri > BASEPRI_DEFAULT && cset->low_pri->current_pri < thread->sched_pri))) {
-                               processor = cset->low_pri;
+               }
+               else {
+
+                       if (thread->sched_pri > lowest_unpaired_primary_priority) {
+                               /* Move to end of active queue so that the next thread doesn't also pick it */
+                               remqueue((queue_entry_t)lp_unpaired_primary_processor);
+                               enqueue_tail(&cset->active_queue, (queue_entry_t)lp_unpaired_primary_processor);
+                               return lp_unpaired_primary_processor;

                        }
                        }

-                       else
-                       if (cset->low_count != PROCESSOR_NULL && cset->low_count->state != PROCESSOR_INACTIVE &&
-                                       cset->low_count->state != PROCESSOR_SHUTDOWN && cset->low_count->state != PROCESSOR_OFF_LINE &&
-                                               (processor == PROCESSOR_NULL || (thread->sched_pri <= BASEPRI_DEFAULT &&
-                                                                                                                       cset->low_count->runq.count < processor->runq.count))) {
-                               processor = cset->low_count;
+                       if (thread->sched_pri > lowest_priority) {
+                               /* Move to end of active queue so that the next thread doesn't also pick it */
+                               remqueue((queue_entry_t)lp_processor);
+                               enqueue_tail(&cset->active_queue, (queue_entry_t)lp_processor);
+                               return lp_processor;

                        }
 
                        /*
                        }
 
                        /*

-                        *      Otherwise, choose an available processor in the set.
+                        * If all primary processor in this pset are running a higher
+                        * priority thread, move on to next pset. Only when we have
+                        * exhausted this search do we fall back to other heuristics.

                         */
                         */

-                       if (processor == PROCESSOR_NULL) {
-                               processor = (processor_t)dequeue_head(&cset->active_queue);
-                               if (processor != PROCESSOR_NULL)
-                                       enqueue_tail(&cset->active_queue, (queue_entry_t)processor);
-                       }
-                       if (processor != PROCESSOR_NULL && pmeta == PROCESSOR_META_NULL) {
-                               if (processor->processor_meta != PROCESSOR_META_NULL &&
-                                   !queue_empty(&processor->processor_meta->idle_queue))
-                                       pmeta = processor->processor_meta;
-                       }

                }
 
                /*
                }
 
                /*

-                *      Move onto the next processor set.
+                * Move onto the next processor set.

                 */
                nset = next_pset(cset);
 
                 */
                nset = next_pset(cset);
 


@@ -2408,62 +3861,54 @@ choose_processor(
        } while (nset != pset);
 
        /*
        } while (nset != pset);
 
        /*

-        *      Make sure that we pick a running processor,
-        *      and that the correct processor set is locked.
+        * Make sure that we pick a running processor,
+        * and that the correct processor set is locked.
+        * Since we may have unlock the candidate processor's
+        * pset, it may have changed state.
+        *
+        * All primary processors are running a higher priority
+        * thread, so the only options left are enqueuing on
+        * the secondary processor that would perturb the least priority
+        * primary, or the least busy primary.

         */
        do {
         */
        do {

-               if (pmeta != PROCESSOR_META_NULL) {
-                       if (cset != pmeta->primary->processor_set) {
-                               pset_unlock(cset);
-
-                               cset = pmeta->primary->processor_set;
-                               pset_lock(cset);
-                       }
-
-                       if (!queue_empty(&pmeta->idle_queue))
-                               return ((processor_t)queue_first(&pmeta->idle_queue));
-
-                       pmeta = PROCESSOR_META_NULL;
-               }
-
-               /*
-                *      If we haven't been able to choose a processor,
-                *      pick the boot processor and return it.
-                */
-               if (processor == PROCESSOR_NULL) {
-                       processor = master_processor;

 
 

+               /* lowest_priority is evaluated in the main loops above */
+               if (lp_unpaired_secondary_processor != PROCESSOR_NULL) {
+                       processor = lp_unpaired_secondary_processor;
+                       lp_unpaired_secondary_processor = PROCESSOR_NULL;
+               } else if (lc_processor != PROCESSOR_NULL) {
+                       processor = lc_processor;
+                       lc_processor = PROCESSOR_NULL;
+               } else {

                        /*
                        /*

-                        *      Check that the correct processor set is
-                        *      returned locked.
+                        * All processors are executing higher
+                        * priority threads, and the lowest_count
+                        * candidate was not usable

                         */
                         */

-                       if (cset != processor->processor_set) {
-                               pset_unlock(cset);
-
-                               cset = processor->processor_set;
-                               pset_lock(cset);
-                       }
-
-                       return (processor);
+                       processor = master_processor;

                }
 
                /*
                }
 
                /*

-                *      Check that the processor set for the chosen
-                *      processor is locked.
+                * Check that the correct processor set is
+                * returned locked.

                 */
                if (cset != processor->processor_set) {
                        pset_unlock(cset);
                 */
                if (cset != processor->processor_set) {
                        pset_unlock(cset);

-

                        cset = processor->processor_set;
                        pset_lock(cset);
                }
 
                /*
                        cset = processor->processor_set;
                        pset_lock(cset);
                }
 
                /*

-                *      We must verify that the chosen processor is still available.
+                * We must verify that the chosen processor is still available.
+                * master_processor is an exception, since we may need to preempt
+                * a running thread on it during processor shutdown (for sleep),
+                * and that thread needs to be enqueued on its runqueue to run
+                * when the processor is restarted.

                 */
                 */

-               if (processor->state == PROCESSOR_INACTIVE ||
-                                       processor->state == PROCESSOR_SHUTDOWN || processor->state == PROCESSOR_OFF_LINE)
+               if (processor != master_processor && (processor->state == PROCESSOR_SHUTDOWN || processor->state == PROCESSOR_OFF_LINE))

                        processor = PROCESSOR_NULL;
                        processor = PROCESSOR_NULL;

+

        } while (processor == PROCESSOR_NULL);
 
        return (processor);
        } while (processor == PROCESSOR_NULL);
 
        return (processor);


@@ -2486,15 +3931,15 @@ thread_setrun(
        processor_t                     processor;
        processor_set_t         pset;
 
        processor_t                     processor;
        processor_set_t         pset;
 

-#if DEBUG

        assert(thread_runnable(thread));
        assert(thread_runnable(thread));

-#endif

        
        /*
         *      Update priority if needed.
         */
        
        /*
         *      Update priority if needed.
         */

-       if (thread->sched_stamp != sched_tick)
-               update_priority(thread);
+       if (SCHED(can_update_priority)(thread))
+               SCHED(update_priority)(thread);
+
+       thread->sfi_class = sfi_thread_classify(thread);

 
        assert(thread->runq == PROCESSOR_NULL);
 
 
        assert(thread->runq == PROCESSOR_NULL);
 


@@ -2509,7 +3954,10 @@ thread_setrun(
                        pset = thread->affinity_set->aset_pset;
                        pset_lock(pset);
 
                        pset = thread->affinity_set->aset_pset;
                        pset_lock(pset);
 

-                       processor = choose_processor(pset, PROCESSOR_NULL, thread);
+                       processor = SCHED(choose_processor)(pset, PROCESSOR_NULL, thread);
+
+                       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+                                                                         (uintptr_t)thread_tid(thread), (uintptr_t)-1, processor->cpu_id, processor->state, 0);

                }
                else
                if (thread->last_processor != PROCESSOR_NULL) {
                }
                else
                if (thread->last_processor != PROCESSOR_NULL) {


@@ -2519,7 +3967,10 @@ thread_setrun(
                        processor = thread->last_processor;
                        pset = processor->processor_set;
                        pset_lock(pset);
                        processor = thread->last_processor;
                        pset = processor->processor_set;
                        pset_lock(pset);

-                       processor = choose_processor(pset, processor, thread);
+                       processor = SCHED(choose_processor)(pset, processor, thread);
+
+                       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+                                                                 (uintptr_t)thread_tid(thread), thread->last_processor->cpu_id, processor->cpu_id, processor->state, 0);

                }
                else {
                        /*
                }
                else {
                        /*


@@ -2537,8 +3988,11 @@ thread_setrun(
                        pset = choose_next_pset(pset);
                        pset_lock(pset);
 
                        pset = choose_next_pset(pset);
                        pset_lock(pset);
 

-                       processor = choose_processor(pset, PROCESSOR_NULL, thread);
+                       processor = SCHED(choose_processor)(pset, PROCESSOR_NULL, thread);

                        task->pset_hint = processor->processor_set;
                        task->pset_hint = processor->processor_set;

+
+                       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+                                                                         (uintptr_t)thread_tid(thread), (uintptr_t)-1, processor->cpu_id, processor->state, 0);

                }
        }
        else {
                }
        }
        else {


@@ -2550,13 +4004,19 @@ thread_setrun(
                processor = thread->bound_processor;
                pset = processor->processor_set;
                pset_lock(pset);
                processor = thread->bound_processor;
                pset = processor->processor_set;
                pset_lock(pset);

+
+               KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+                                                         (uintptr_t)thread_tid(thread), (uintptr_t)-2, processor->cpu_id, processor->state, 0);

        }
 
        /*
         *      Dispatch the thread on the choosen processor.
        }
 
        /*
         *      Dispatch the thread on the choosen processor.

+        *      TODO: This should be based on sched_mode, not sched_pri

         */
        if (thread->sched_pri >= BASEPRI_RTQUEUES)
                realtime_setrun(processor, thread);
         */
        if (thread->sched_pri >= BASEPRI_RTQUEUES)
                realtime_setrun(processor, thread);

+       else if (thread->sched_mode == TH_MODE_FAIRSHARE)
+               fairshare_setrun(processor, thread);

        else
                processor_setrun(processor, thread, options);
 }
        else
                processor_setrun(processor, thread, options);
 }


@@ -2573,6 +4033,8 @@ task_choose_pset(
        return (pset);
 }
 
        return (pset);
 }
 

+#if defined(CONFIG_SCHED_TRADITIONAL)
+

 /*
  *     processor_queue_shutdown:
  *
 /*
  *     processor_queue_shutdown:
  *


@@ -2587,7 +4049,7 @@ processor_queue_shutdown(
        processor_t                     processor)
 {
        processor_set_t         pset = processor->processor_set;
        processor_t                     processor)
 {
        processor_set_t         pset = processor->processor_set;

-       run_queue_t                     rq = &processor->runq;
+       run_queue_t                     rq = runq_for_processor(processor);

        queue_t                         queue = rq->queues + rq->highq;
        int                                     pri = rq->highq, count = rq->count;
        thread_t                        next, thread;
        queue_t                         queue = rq->queues + rq->highq;
        int                                     pri = rq->highq, count = rq->count;
        thread_t                        next, thread;


@@ -2601,11 +4063,13 @@ processor_queue_shutdown(
                        next = (thread_t)queue_next((queue_entry_t)thread);
 
                        if (thread->bound_processor == PROCESSOR_NULL) {
                        next = (thread_t)queue_next((queue_entry_t)thread);
 
                        if (thread->bound_processor == PROCESSOR_NULL) {

-                               remqueue(queue, (queue_entry_t)thread);
+                               remqueue((queue_entry_t)thread);

 
                                thread->runq = PROCESSOR_NULL;
 
                                thread->runq = PROCESSOR_NULL;

+                               SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+                               runq_consider_decr_bound_count(processor, thread);

                                rq->count--;
                                rq->count--;

-                               if (testbit(pri, sched_preempt_pri)) {
+                               if (SCHED(priority_is_urgent)(pri)) {

                                        rq->urgency--; assert(rq->urgency >= 0);
                                }
                                if (queue_empty(queue)) {
                                        rq->urgency--; assert(rq->urgency >= 0);
                                }
                                if (queue_empty(queue)) {


@@ -2635,69 +4099,77 @@ processor_queue_shutdown(
        }
 }
 
        }
 }
 

+#endif /* CONFIG_SCHED_TRADITIONAL */
+

 /*
  *     Check for a preemption point in
  *     the current context.
  *
 /*
  *     Check for a preemption point in
  *     the current context.
  *

- *     Called at splsched.
+ *     Called at splsched with thread locked.

  */
 ast_t
 csw_check(
  */
 ast_t
 csw_check(

-       processor_t             processor)
+       processor_t             processor,
+       ast_t                   check_reason)

 {
 {

-       ast_t                   result = AST_NONE;
-       run_queue_t             runq;
-
-       if (first_timeslice(processor)) {
-               runq = &rt_runq;
-               if (runq->highq >= BASEPRI_RTQUEUES)
-                       return (AST_PREEMPT | AST_URGENT);
+       processor_set_t pset = processor->processor_set;
+       ast_t                   result;

 
 

-               if (runq->highq > processor->current_pri) {
-                       if (runq->urgency > 0)
-                               return (AST_PREEMPT | AST_URGENT);
+       pset_lock(pset);

 
 

-                       result |= AST_PREEMPT;
-               }
+       /* If we were sent a remote AST and interrupted a running processor, acknowledge it here with pset lock held */
+       pset->pending_AST_cpu_mask &= ~(1U << processor->cpu_id);

 
 

-               runq = &processor->runq;
-               if (runq->highq > processor->current_pri) {
-                       if (runq->urgency > 0)
-                               return (AST_PREEMPT | AST_URGENT);
+       result = csw_check_locked(processor, pset, check_reason);

 
 

-                       result |= AST_PREEMPT;
-               }
-       }
-       else {
-               runq = &rt_runq;
-               if (runq->highq >= processor->current_pri) {
-                       if (runq->urgency > 0)
-                               return (AST_PREEMPT | AST_URGENT);
+       pset_unlock(pset);

 
 

-                       result |= AST_PREEMPT;
-               }
+       return result;
+}

 
 

-               runq = &processor->runq;
-               if (runq->highq >= processor->current_pri) {
-                       if (runq->urgency > 0)
-                               return (AST_PREEMPT | AST_URGENT);
+/*
+ * Check for preemption at splsched with
+ * pset and thread locked
+ */
+ast_t
+csw_check_locked(
+       processor_t             processor,
+       processor_set_t pset __unused,
+       ast_t                   check_reason)
+{
+       ast_t                   result;
+       thread_t                thread = processor->active_thread;

 
 

-                       result |= AST_PREEMPT;
+       if (first_timeslice(processor)) {
+               if (rt_runq.count > 0)
+                       return (check_reason | AST_PREEMPT | AST_URGENT);
+       }
+       else {
+               if (rt_runq.count > 0) {
+                       if (BASEPRI_RTQUEUES > processor->current_pri)
+                               return (check_reason | AST_PREEMPT | AST_URGENT);
+                       else
+                               return (check_reason | AST_PREEMPT);

                }
        }
 
                }
        }
 

+       result = SCHED(processor_csw_check)(processor);

        if (result != AST_NONE)
        if (result != AST_NONE)

-               return (result);
+               return (check_reason | result);

 
 

-       if (processor->current_pri < BASEPRI_RTQUEUES && processor->processor_meta != PROCESSOR_META_NULL &&
-                               processor->processor_meta->primary != processor)
-               return (AST_PREEMPT);
-
-       if (machine_processor_is_inactive(processor))
-               return (AST_PREEMPT);
+       if (SCHED(should_current_thread_rechoose_processor)(processor))
+               return (check_reason | AST_PREEMPT);
+       
+       if (thread->state & TH_SUSP)
+               return (check_reason | AST_PREEMPT);

 
 

-       if (processor->active_thread->state & TH_SUSP)
-               return (AST_PREEMPT);
+       /*
+        * Current thread may not need to be preempted, but maybe needs
+        * an SFI wait?
+        */
+       result = sfi_thread_needs_ast(thread, NULL);
+       if (result != AST_NONE)
+               return (check_reason | result);

 
        return (AST_NONE);
 }
 
        return (AST_NONE);
 }


@@ -2714,11 +4186,31 @@ csw_check(
 void
 set_sched_pri(
        thread_t                thread,
 void
 set_sched_pri(
        thread_t                thread,

-       int                             priority)
+       int                     priority)

 {
 {

-       boolean_t               removed = run_queue_remove(thread);
+       boolean_t               removed = thread_run_queue_remove(thread);
+       int curgency, nurgency;
+       uint64_t urgency_param1, urgency_param2;
+       thread_t cthread = current_thread();

 
 

+       if (thread == cthread) {
+               curgency = thread_get_urgency(thread, &urgency_param1, &urgency_param2);
+       }
+       

        thread->sched_pri = priority;
        thread->sched_pri = priority;

+
+       if (thread == cthread) {
+               nurgency = thread_get_urgency(thread, &urgency_param1, &urgency_param2);
+/* set_sched_pri doesn't alter RT params. We expect direct base priority/QoS
+ * class alterations from user space to occur relatively infrequently, hence
+ * those are lazily handled. QoS classes have distinct priority bands, and QoS
+ * inheritance is expected to involve priority changes.
+ */
+               if (nurgency != curgency) {
+                       thread_tell_urgency(nurgency, urgency_param1, urgency_param2, thread);
+               }
+       }
+

        if (removed)
                thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ);
        else
        if (removed)
                thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ);
        else


@@ -2729,7 +4221,9 @@ set_sched_pri(
                        ast_t                   preempt;
 
                        processor->current_pri = priority;
                        ast_t                   preempt;
 
                        processor->current_pri = priority;

-                       if ((preempt = csw_check(processor)) != AST_NONE)
+                       processor->current_thmode = thread->sched_mode;
+                       processor->current_sfi_class = thread->sfi_class = sfi_thread_classify(thread);
+                       if ((preempt = csw_check(processor, AST_NONE)) != AST_NONE)

                                ast_on(preempt);
                }
                else
                                ast_on(preempt);
                }
                else


@@ -2769,80 +4263,129 @@ run_queue_check(
 
 #endif /* DEBUG */
 
 
 #endif /* DEBUG */
 

+#if defined(CONFIG_SCHED_TRADITIONAL)
+

 /*
 /*

- *     run_queue_remove:
+ * Locks the runqueue itself.
+ *
+ * Thread must be locked.
+ */
+static boolean_t
+processor_queue_remove(
+                                          processor_t                  processor,
+                                          thread_t             thread)
+{
+       void *                  rqlock;
+       run_queue_t             rq;
+       
+       rqlock = &processor->processor_set->sched_lock;
+       rq = runq_for_processor(processor);
+
+       simple_lock(rqlock);
+       if (processor == thread->runq) {
+               /*
+                *      Thread is on a run queue and we have a lock on
+                *      that run queue.
+                */
+               runq_consider_decr_bound_count(processor, thread);
+               run_queue_remove(rq, thread);
+       }
+       else {
+               /*
+                *      The thread left the run queue before we could
+                *      lock the run queue.
+                */
+               assert(thread->runq == PROCESSOR_NULL);
+               processor = PROCESSOR_NULL;
+       }
+       
+       simple_unlock(rqlock);
+
+       return (processor != PROCESSOR_NULL);
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+
+/*
+ *     thread_run_queue_remove:

  *
  *

- *     Remove a thread from a current run queue and
+ *     Remove a thread from its current run queue and

  *     return TRUE if successful.
  *
  *     Thread must be locked.
  *     return TRUE if successful.
  *
  *     Thread must be locked.

+ *
+ *     If thread->runq is PROCESSOR_NULL, the thread will not re-enter the
+ *     run queues because the caller locked the thread.  Otherwise
+ *     the thread is on a run queue, but could be chosen for dispatch
+ *     and removed by another processor under a different lock, which
+ *     will set thread->runq to PROCESSOR_NULL.
+ *
+ *     Hence the thread select path must not rely on anything that could
+ *     be changed under the thread lock after calling this function,
+ *     most importantly thread->sched_pri.

  */
 boolean_t
  */
 boolean_t

-run_queue_remove(
-       thread_t                thread)
+thread_run_queue_remove(
+                        thread_t        thread)

 {
 {

-       processor_t             processor = thread->runq;
+       boolean_t removed = FALSE;
+       processor_t processor = thread->runq;

 
 

-       /*
-        *      If processor is PROCESSOR_NULL, the thread will stay out of the
-        *      run queues because the caller locked the thread.  Otherwise
-        *      the thread is on a run queue, but could be chosen for dispatch
-        *      and removed.
-        */
-       if (processor != PROCESSOR_NULL) {
-               void *                  rqlock;
-               run_queue_t             rq;
+       if ((thread->state & (TH_RUN|TH_WAIT)) == TH_WAIT) {
+               /* Thread isn't runnable */
+               assert(thread->runq == PROCESSOR_NULL);
+               return FALSE;
+       }

 
 

+       if (processor == PROCESSOR_NULL) {

                /*
                /*

-                *      The processor run queues are locked by the
-                *      processor set.  Real-time priorities use a
-                *      global queue with a dedicated lock.
+                * The thread is either not on the runq,
+                * or is in the midst of being removed from the runq.
+                *
+                * runq is set to NULL under the pset lock, not the thread
+                * lock, so the thread may still be in the process of being dequeued
+                * from the runq. It will wait in invoke for the thread lock to be
+                * dropped.

                 */
                 */

-               if (thread->sched_pri < BASEPRI_RTQUEUES) {
-                       rqlock = &processor->processor_set->sched_lock;
-                       rq = &processor->runq;
-               }
-               else {
-                       rqlock = &rt_lock; rq = &rt_runq;
-               }

 
 

-               simple_lock(rqlock);
+               return FALSE;
+       }

 
 

-               if (processor == thread->runq) {
-                       /*
-                        *      Thread is on a run queue and we have a lock on
-                        *      that run queue.
-                        */
-                       remqueue(&rq->queues[0], (queue_entry_t)thread);
-                       rq->count--;
-                       if (testbit(thread->sched_pri, sched_preempt_pri)) {
-                               rq->urgency--; assert(rq->urgency >= 0);
-                       }
+       if (thread->sched_mode == TH_MODE_FAIRSHARE) {
+               return SCHED(fairshare_queue_remove)(thread);
+       }
+       
+       if (thread->sched_pri < BASEPRI_RTQUEUES) {
+               return SCHED(processor_queue_remove)(processor, thread);
+       }

 
 

-                       if (queue_empty(rq->queues + thread->sched_pri)) {
-                               /* update run queue status */
-                               if (thread->sched_pri != IDLEPRI)
-                                       clrbit(MAXPRI - thread->sched_pri, rq->bitmap);
-                               rq->highq = MAXPRI - ffsbit(rq->bitmap);
-                       }
+       simple_lock(&rt_lock);

 
 

-                       thread->runq = PROCESSOR_NULL;
-               }
-               else {
-                       /*
-                        *      The thread left the run queue before we could
-                        *      lock the run queue.
-                        */
-                       assert(thread->runq == PROCESSOR_NULL);
-                       processor = PROCESSOR_NULL;
-               }
+       if (thread->runq != PROCESSOR_NULL) {
+               /*
+                *      Thread is on a run queue and we have a lock on
+                *      that run queue.
+                */
+
+               assert(thread->runq == RT_RUNQ);

 
 

-               simple_unlock(rqlock);
+               remqueue((queue_entry_t)thread);
+               SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+               rt_runq.count--;
+
+               thread->runq = PROCESSOR_NULL;
+
+               removed = TRUE;

        }
 
        }
 

-       return (processor != PROCESSOR_NULL);
+       simple_unlock(&rt_lock);
+
+       return (removed);

 }
 
 }
 

+#if defined(CONFIG_SCHED_TRADITIONAL)
+

 /*
  *     steal_processor_thread:
  *
 /*
  *     steal_processor_thread:
  *


@@ -2856,7 +4399,7 @@ static thread_t
 steal_processor_thread(
        processor_t             processor)
 {
 steal_processor_thread(
        processor_t             processor)
 {

-       run_queue_t             rq = &processor->runq;
+       run_queue_t             rq = runq_for_processor(processor);

        queue_t                 queue = rq->queues + rq->highq;
        int                             pri = rq->highq, count = rq->count;
        thread_t                thread;
        queue_t                 queue = rq->queues + rq->highq;
        int                             pri = rq->highq, count = rq->count;
        thread_t                thread;


@@ -2865,11 +4408,13 @@ steal_processor_thread(
                thread = (thread_t)queue_first(queue);
                while (!queue_end(queue, (queue_entry_t)thread)) {
                        if (thread->bound_processor == PROCESSOR_NULL) {
                thread = (thread_t)queue_first(queue);
                while (!queue_end(queue, (queue_entry_t)thread)) {
                        if (thread->bound_processor == PROCESSOR_NULL) {

-                               remqueue(queue, (queue_entry_t)thread);
+                               remqueue((queue_entry_t)thread);

 
                                thread->runq = PROCESSOR_NULL;
 
                                thread->runq = PROCESSOR_NULL;

+                               SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+                               runq_consider_decr_bound_count(processor, thread);

                                rq->count--;
                                rq->count--;

-                               if (testbit(pri, sched_preempt_pri)) {
+                               if (SCHED(priority_is_urgent)(pri)) {

                                        rq->urgency--; assert(rq->urgency >= 0);
                                }
                                if (queue_empty(queue)) {
                                        rq->urgency--; assert(rq->urgency >= 0);
                                }
                                if (queue_empty(queue)) {


@@ -2912,10 +4457,10 @@ steal_thread(
        do {
                processor = (processor_t)queue_first(&cset->active_queue);
                while (!queue_end(&cset->active_queue, (queue_entry_t)processor)) {
        do {
                processor = (processor_t)queue_first(&cset->active_queue);
                while (!queue_end(&cset->active_queue, (queue_entry_t)processor)) {

-                       if (processor->runq.count > 0) {
+                       if (runq_for_processor(processor)->count > 0) {

                                thread = steal_processor_thread(processor);
                                if (thread != THREAD_NULL) {
                                thread = steal_processor_thread(processor);
                                if (thread != THREAD_NULL) {

-                                       remqueue(&cset->active_queue, (queue_entry_t)processor);
+                                       remqueue((queue_entry_t)processor);

                                        enqueue_tail(&cset->active_queue, (queue_entry_t)processor);
 
                                        pset_unlock(cset);
                                        enqueue_tail(&cset->active_queue, (queue_entry_t)processor);
 
                                        pset_unlock(cset);


@@ -2942,6 +4487,61 @@ steal_thread(
        return (THREAD_NULL);
 }
 
        return (THREAD_NULL);
 }
 

+static thread_t        steal_thread_disabled(
+                                       processor_set_t         pset)
+{
+       pset_unlock(pset);
+
+       return (THREAD_NULL);
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+
+void
+sys_override_cpu_throttle(int flag)
+{
+       if (flag == CPU_THROTTLE_ENABLE)
+               cpu_throttle_enabled = 1;
+       if (flag == CPU_THROTTLE_DISABLE)
+               cpu_throttle_enabled = 0;
+}
+
+int
+thread_get_urgency(thread_t thread, uint64_t *arg1, uint64_t *arg2)
+{
+       if (thread == NULL || (thread->state & TH_IDLE)) {
+               *arg1 = 0;
+               *arg2 = 0;
+
+               return (THREAD_URGENCY_NONE);
+       } else if (thread->sched_mode == TH_MODE_REALTIME) {
+               *arg1 = thread->realtime.period;
+               *arg2 = thread->realtime.deadline;
+
+               return (THREAD_URGENCY_REAL_TIME);
+       } else if (cpu_throttle_enabled &&
+                  ((thread->sched_pri <= MAXPRI_THROTTLE) && (thread->priority <= MAXPRI_THROTTLE)))  {
+               /*
+                * Background urgency applied when thread priority is MAXPRI_THROTTLE or lower and thread is not promoted
+                * TODO: Use TH_SFLAG_THROTTLED instead?
+                */
+               *arg1 = thread->sched_pri;
+               *arg2 = thread->priority;
+
+               return (THREAD_URGENCY_BACKGROUND);
+       } else {
+               /* For otherwise unclassified threads, report throughput QoS
+                * parameters
+                */
+               *arg1 = thread->effective_policy.t_through_qos;
+               *arg2 = thread->task->effective_policy.t_through_qos;
+               
+               return (THREAD_URGENCY_NORMAL);
+       }
+}
+
+

 /*
  *     This is the processor idle loop, which just looks for other threads
  *     to execute.  Processor idle threads invoke this without supplying a
 /*
  *     This is the processor idle loop, which just looks for other threads
  *     to execute.  Processor idle threads invoke this without supplying a


@@ -2949,7 +4549,14 @@ steal_thread(
  *
  *     Returns a the next thread to execute if dispatched directly.
  */
  *
  *     Returns a the next thread to execute if dispatched directly.
  */

-static thread_t
+
+#if 0
+#define IDLE_KERNEL_DEBUG_CONSTANT(...) KERNEL_DEBUG_CONSTANT(__VA_ARGS__)
+#else
+#define IDLE_KERNEL_DEBUG_CONSTANT(...) do { } while(0)
+#endif
+
+thread_t

 processor_idle(
        thread_t                        thread,
        processor_t                     processor)
 processor_idle(
        thread_t                        thread,
        processor_t                     processor)


@@ -2957,24 +4564,54 @@ processor_idle(
        processor_set_t         pset = processor->processor_set;
        thread_t                        new_thread;
        int                                     state;
        processor_set_t         pset = processor->processor_set;
        thread_t                        new_thread;
        int                                     state;

-

        (void)splsched();
 
        (void)splsched();
 

-       KERNEL_DEBUG_CONSTANT(
-               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_START, (uintptr_t)thread_tid(thread), 0, 0, 0, 0);
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_START, 
+               (uintptr_t)thread_tid(thread), 0, 0, 0, 0);
+
+       SCHED_STATS_CPU_IDLE_START(processor);

 
        timer_switch(&PROCESSOR_DATA(processor, system_state),
                                                                        mach_absolute_time(), &PROCESSOR_DATA(processor, idle_state));
        PROCESSOR_DATA(processor, current_state) = &PROCESSOR_DATA(processor, idle_state);
 
 
        timer_switch(&PROCESSOR_DATA(processor, system_state),
                                                                        mach_absolute_time(), &PROCESSOR_DATA(processor, idle_state));
        PROCESSOR_DATA(processor, current_state) = &PROCESSOR_DATA(processor, idle_state);
 

-       while (processor->next_thread == THREAD_NULL && processor->runq.count == 0 && rt_runq.count == 0 &&
-                               (thread == THREAD_NULL || ((thread->state & (TH_WAIT|TH_SUSP)) == TH_WAIT && !thread->wake_active))) {
+       while (1) {
+               if (processor->state != PROCESSOR_IDLE) /* unsafe, but worst case we loop around once */
+                       break;
+               if (pset->pending_AST_cpu_mask & (1U << processor->cpu_id))
+                       break;
+               if (rt_runq.count)
+                       break;
+#if CONFIG_SCHED_IDLE_IN_PLACE
+               if (thread != THREAD_NULL) {
+                       /* Did idle-in-place thread wake up */
+                       if ((thread->state & (TH_WAIT|TH_SUSP)) != TH_WAIT || thread->wake_active)
+                               break;
+               }
+#endif
+
+               IDLE_KERNEL_DEBUG_CONSTANT(
+                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_NONE, (uintptr_t)thread_tid(thread), rt_runq.count, SCHED(processor_runq_count)(processor), -1, 0);
+
+               machine_track_platform_idle(TRUE);
+

                machine_idle();
 
                machine_idle();
 

+               machine_track_platform_idle(FALSE);
+

                (void)splsched();
 
                (void)splsched();
 

-               if (processor->state == PROCESSOR_INACTIVE && !machine_processor_is_inactive(processor))
-                       break;
+               IDLE_KERNEL_DEBUG_CONSTANT(
+                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_NONE, (uintptr_t)thread_tid(thread), rt_runq.count, SCHED(processor_runq_count)(processor), -2, 0);
+
+               if (!SCHED(processor_queue_empty)(processor)) {
+                       /* Secondary SMT processors respond to directed wakeups
+                        * exclusively. Some platforms induce 'spurious' SMT wakeups.
+                        */
+                       if (processor->processor_primary == processor)
+                                       break;
+               }

        }
 
        timer_switch(&PROCESSOR_DATA(processor, idle_state),
        }
 
        timer_switch(&PROCESSOR_DATA(processor, idle_state),


@@ -2983,6 +4620,9 @@ processor_idle(
 
        pset_lock(pset);
 
 
        pset_lock(pset);
 

+       /* If we were sent a remote AST and came out of idle, acknowledge it here with pset lock held */
+       pset->pending_AST_cpu_mask &= ~(1U << processor->cpu_id);
+

        state = processor->state;
        if (state == PROCESSOR_DISPATCHING) {
                /*
        state = processor->state;
        if (state == PROCESSOR_DISPATCHING) {
                /*


@@ -2992,39 +4632,45 @@ processor_idle(
                processor->next_thread = THREAD_NULL;
                processor->state = PROCESSOR_RUNNING;
 
                processor->next_thread = THREAD_NULL;
                processor->state = PROCESSOR_RUNNING;
 

-               if (    processor->runq.highq > new_thread->sched_pri                                   ||
-                               (rt_runq.highq > 0 && rt_runq.highq >= new_thread->sched_pri)   ) {
+               if ((new_thread != THREAD_NULL) && (SCHED(processor_queue_has_priority)(processor, new_thread->sched_pri, FALSE)                                        ||
+                                                                                       (rt_runq.count > 0 && BASEPRI_RTQUEUES >= new_thread->sched_pri))       ) {
+                       /* Something higher priority has popped up on the runqueue - redispatch this thread elsewhere */
+                       processor->current_pri = IDLEPRI;
+                       processor->current_thmode = TH_MODE_FIXED;
+                       processor->current_sfi_class = SFI_CLASS_KERNEL;

                        processor->deadline = UINT64_MAX;
 
                        pset_unlock(pset);
 
                        thread_lock(new_thread);
                        processor->deadline = UINT64_MAX;
 
                        pset_unlock(pset);
 
                        thread_lock(new_thread);

+                       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_REDISPATCH), (uintptr_t)thread_tid(new_thread), new_thread->sched_pri, rt_runq.count, 0, 0);

                        thread_setrun(new_thread, SCHED_HEADQ);
                        thread_unlock(new_thread);
 
                        thread_setrun(new_thread, SCHED_HEADQ);
                        thread_unlock(new_thread);
 

-                       KERNEL_DEBUG_CONSTANT(
-                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, (uintptr_t)thread_tid(thread), state, 0, 0, 0);
-       
+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, 
+                               (uintptr_t)thread_tid(thread), state, 0, 0, 0);
+

                        return (THREAD_NULL);
                }
 
                pset_unlock(pset);
 
                        return (THREAD_NULL);
                }
 
                pset_unlock(pset);
 

-               KERNEL_DEBUG_CONSTANT(
-                                     MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, (uintptr_t)thread_tid(thread), state, (uintptr_t)thread_tid(new_thread), 0, 0);
-
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                       MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, 
+                       (uintptr_t)thread_tid(thread), state, (uintptr_t)thread_tid(new_thread), 0, 0);
+                       

                return (new_thread);
        }
        else
        if (state == PROCESSOR_IDLE) {
                return (new_thread);
        }
        else
        if (state == PROCESSOR_IDLE) {

-               remqueue(&pset->idle_queue, (queue_entry_t)processor);
+               remqueue((queue_entry_t)processor);

 
                processor->state = PROCESSOR_RUNNING;
 
                processor->state = PROCESSOR_RUNNING;

-               enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
-       }
-       else
-       if (state == PROCESSOR_INACTIVE) {
-               processor->state = PROCESSOR_RUNNING;
+               processor->current_pri = IDLEPRI;
+               processor->current_thmode = TH_MODE_FIXED;
+               processor->current_sfi_class = SFI_CLASS_KERNEL;
+               processor->deadline = UINT64_MAX;

                enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
        }
        else
                enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
        }
        else


@@ -3035,6 +4681,9 @@ processor_idle(
                 */
                if ((new_thread = processor->next_thread) != THREAD_NULL) {
                        processor->next_thread = THREAD_NULL;
                 */
                if ((new_thread = processor->next_thread) != THREAD_NULL) {
                        processor->next_thread = THREAD_NULL;

+                       processor->current_pri = IDLEPRI;
+                       processor->current_thmode = TH_MODE_FIXED;
+                       processor->current_sfi_class = SFI_CLASS_KERNEL;

                        processor->deadline = UINT64_MAX;
 
                        pset_unlock(pset);
                        processor->deadline = UINT64_MAX;
 
                        pset_unlock(pset);


@@ -3043,18 +4692,20 @@ processor_idle(
                        thread_setrun(new_thread, SCHED_HEADQ);
                        thread_unlock(new_thread);
 
                        thread_setrun(new_thread, SCHED_HEADQ);
                        thread_unlock(new_thread);
 

-                       KERNEL_DEBUG_CONSTANT(
-                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, (uintptr_t)thread_tid(thread), state, 0, 0, 0);
-
+                       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, 
+                               (uintptr_t)thread_tid(thread), state, 0, 0, 0);
+               

                        return (THREAD_NULL);
                }
        }
 
        pset_unlock(pset);
 
                        return (THREAD_NULL);
                }
        }
 
        pset_unlock(pset);
 

-       KERNEL_DEBUG_CONSTANT(
-               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, (uintptr_t)thread_tid(thread), state, 0, 0, 0);
-
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+               MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END, 
+               (uintptr_t)thread_tid(thread), state, 0, 0, 0);
+               

        return (THREAD_NULL);
 }
 
        return (THREAD_NULL);
 }
 


@@ -3097,6 +4748,7 @@ idle_thread_create(
        processor->idle_thread = thread;
        thread->sched_pri = thread->priority = IDLEPRI;
        thread->state = (TH_RUN | TH_IDLE);
        processor->idle_thread = thread;
        thread->sched_pri = thread->priority = IDLEPRI;
        thread->state = (TH_RUN | TH_IDLE);

+       thread->options |= TH_OPT_IDLE_THREAD;

        thread_unlock(thread);
        splx(s);
 
        thread_unlock(thread);
        splx(s);
 


@@ -3105,8 +4757,6 @@ idle_thread_create(
        return (KERN_SUCCESS);
 }
 
        return (KERN_SUCCESS);
 }
 

-static uint64_t                sched_tick_deadline;
-

 /*
  * sched_startup:
  *
 /*
  * sched_startup:
  *


@@ -3120,105 +4770,173 @@ sched_startup(void)
        kern_return_t   result;
        thread_t                thread;
 
        kern_return_t   result;
        thread_t                thread;
 

-       result = kernel_thread_start_priority((thread_continue_t)sched_tick_thread, NULL, MAXPRI_KERNEL, &thread);
+       result = kernel_thread_start_priority((thread_continue_t)sched_init_thread,
+           (void *)SCHED(maintenance_continuation), MAXPRI_KERNEL, &thread);

        if (result != KERN_SUCCESS)
                panic("sched_startup");
 
        thread_deallocate(thread);
 
        /*
        if (result != KERN_SUCCESS)
                panic("sched_startup");
 
        thread_deallocate(thread);
 
        /*

-        * Yield to the sched_tick_thread while it times
-        * a series of context switches back.  It stores
-        * the baseline value in sched_cswtime.
+        * Yield to the sched_init_thread once, to
+        * initialize our own thread after being switched
+        * back to.

         *
         * The current thread is the only other thread
         * active at this point.
         */
         *
         * The current thread is the only other thread
         * active at this point.
         */

-       while (sched_cswtime == 0)
-               thread_block(THREAD_CONTINUE_NULL);
-
-       thread_daemon_init();
-
-       thread_call_initialize();
+       thread_block(THREAD_CONTINUE_NULL);

 }
 
 }
 

+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+static volatile uint64_t               sched_maintenance_deadline;
+#if defined(CONFIG_TELEMETRY)
+static volatile uint64_t               sched_telemetry_deadline = 0;
+#endif
+static uint64_t                                sched_tick_last_abstime;
+static uint64_t                                sched_tick_delta;
+uint64_t                               sched_tick_max_delta;

 /*
 /*

- *     sched_tick_thread:
+ *     sched_init_thread:

  *
  *     Perform periodic bookkeeping functions about ten
  *     times per second.
  */
  *
  *     Perform periodic bookkeeping functions about ten
  *     times per second.
  */

-static void
-sched_tick_continue(void)
+void
+sched_traditional_maintenance_continue(void)

 {
 {

-       uint64_t                        abstime = mach_absolute_time();
+       uint64_t        sched_tick_ctime, late_time;
+
+       sched_tick_ctime = mach_absolute_time();        
+
+       if (__improbable(sched_tick_last_abstime == 0)) {
+               sched_tick_last_abstime = sched_tick_ctime;
+               late_time = 0;
+               sched_tick_delta = 1;
+       } else {
+               late_time = sched_tick_ctime - sched_tick_last_abstime;
+               sched_tick_delta = late_time / sched_tick_interval;
+               /* Ensure a delta of 1, since the interval could be slightly
+                * smaller than the sched_tick_interval due to dispatch
+                * latencies.
+                */
+               sched_tick_delta = MAX(sched_tick_delta, 1);

 
 

-       sched_tick++;
+               /* In the event interrupt latencies or platform
+                * idle events that advanced the timebase resulted
+                * in periods where no threads were dispatched,
+                * cap the maximum "tick delta" at SCHED_TICK_MAX_DELTA
+                * iterations.
+                */
+               sched_tick_delta = MIN(sched_tick_delta, SCHED_TICK_MAX_DELTA);
+
+               sched_tick_last_abstime = sched_tick_ctime;
+               sched_tick_max_delta = MAX(sched_tick_delta, sched_tick_max_delta);
+       }
+
+       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_MAINTENANCE)|DBG_FUNC_START,
+                                                 sched_tick_delta,
+                                                 late_time,
+                                                 0,
+                                                 0,
+                                                 0);
+
+       /* Add a number of pseudo-ticks corresponding to the elapsed interval
+        * This could be greater than 1 if substantial intervals where
+        * all processors are idle occur, which rarely occurs in practice.
+        */
+       
+       sched_tick += sched_tick_delta;

 
        /*
         *  Compute various averages.
         */
 
        /*
         *  Compute various averages.
         */

-       compute_averages();
+       compute_averages(sched_tick_delta);

 
        /*
         *  Scan the run queues for threads which
         *  may need to be updated.
         */
 
        /*
         *  Scan the run queues for threads which
         *  may need to be updated.
         */

-       thread_update_scan();
+       SCHED(thread_update_scan)();

 
 

-       clock_deadline_for_periodic_event(sched_tick_interval, abstime,
-                                                                                                               &sched_tick_deadline);
+       KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_MAINTENANCE)|DBG_FUNC_END,
+                                                 sched_pri_shift,
+                                                 sched_background_pri_shift,
+                                                 0,
+                                                 0,
+                                                 0);

 
 

-       assert_wait_deadline((event_t)sched_tick_thread, THREAD_UNINT, sched_tick_deadline);
-       thread_block((thread_continue_t)sched_tick_continue);
+       assert_wait((event_t)sched_traditional_maintenance_continue, THREAD_UNINT);
+       thread_block((thread_continue_t)sched_traditional_maintenance_continue);

        /*NOTREACHED*/
 }
 
        /*NOTREACHED*/
 }
 

+static uint64_t sched_maintenance_wakeups;
+

 /*
 /*

- * Time a series of context switches to determine
- * a baseline.  Toss the high and low and return
- * the one-way value.
+ * Determine if the set of routines formerly driven by a maintenance timer
+ * must be invoked, based on a deadline comparison. Signals the scheduler
+ * maintenance thread on deadline expiration. Must be invoked at an interval
+ * lower than the "sched_tick_interval", currently accomplished by
+ * invocation via the quantum expiration timer and at context switch time.
+ * Performance matters: this routine reuses a timestamp approximating the
+ * current absolute time received from the caller, and should perform
+ * no more than a comparison against the deadline in the common case.

  */
  */

-static uint32_t
-time_cswitch(void)
-{
-       uint32_t        new, hi, low, accum;
-       uint64_t        abstime;
-       int                     i, tries = 7;
+void
+sched_traditional_consider_maintenance(uint64_t ctime) {
+       uint64_t ndeadline, deadline = sched_maintenance_deadline;

 
 

-       accum = hi = low = 0;
-       for (i = 0; i < tries; ++i) {
-               abstime = mach_absolute_time();
-               thread_block(THREAD_CONTINUE_NULL);
+       if (__improbable(ctime >= deadline)) {
+               if (__improbable(current_thread() == sched_maintenance_thread))
+                       return;
+               OSMemoryBarrier();

 
 

-               new = (uint32_t)(mach_absolute_time() - abstime);
+               ndeadline = ctime + sched_tick_interval;

 
 

-               if (i == 0)
-                       accum = hi = low = new;
-               else {
-                       if (new < low)
-                               low = new;
-                       else
-                       if (new > hi)
-                               hi = new;
-                       accum += new;
+               if (__probable(__sync_bool_compare_and_swap(&sched_maintenance_deadline, deadline, ndeadline))) {
+                       thread_wakeup((event_t)sched_traditional_maintenance_continue);
+                       sched_maintenance_wakeups++;

                }
        }
 
                }
        }
 

-       return ((accum - hi - low) / (2 * (tries - 2)));
+#if defined(CONFIG_TELEMETRY)
+       /*
+        * Windowed telemetry is driven by the scheduler.  It should be safe
+        * to call compute_telemetry_windowed() even when windowed telemetry
+        * is disabled, but we should try to avoid doing extra work for no
+        * reason.
+        */
+       if (telemetry_window_enabled) {
+               deadline = sched_telemetry_deadline;
+
+               if (__improbable(ctime >= deadline)) {
+                       ndeadline = ctime + sched_telemetry_interval;
+
+                       if (__probable(__sync_bool_compare_and_swap(&sched_telemetry_deadline, deadline, ndeadline))) {
+                               compute_telemetry_windowed();
+                       }
+               }
+       }
+#endif /* CONFIG_TELEMETRY */

 }
 
 }
 

+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+

 void
 void

-sched_tick_thread(void)
+sched_init_thread(void (*continuation)(void))

 {
 {

-       sched_cswtime = time_cswitch();
+       thread_block(THREAD_CONTINUE_NULL);

 
 

-       sched_tick_deadline = mach_absolute_time();
+       sched_maintenance_thread = current_thread();
+       continuation();

 
 

-       sched_tick_continue();

        /*NOTREACHED*/
 }
 
        /*NOTREACHED*/
 }
 

+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+

 /*
  *     thread_update_scan / runq_scan:
  *
 /*
  *     thread_update_scan / runq_scan:
  *


@@ -3240,12 +4958,44 @@ sched_tick_thread(void)
 static thread_t                thread_update_array[THREAD_UPDATE_SIZE];
 static int                     thread_update_count = 0;
 
 static thread_t                thread_update_array[THREAD_UPDATE_SIZE];
 static int                     thread_update_count = 0;
 

+/* Returns TRUE if thread was added, FALSE if thread_update_array is full */
+boolean_t
+thread_update_add_thread(thread_t thread)
+{
+       if (thread_update_count == THREAD_UPDATE_SIZE)
+               return (FALSE);
+
+       thread_update_array[thread_update_count++] = thread;
+       thread_reference_internal(thread);
+       return (TRUE);
+}
+
+void
+thread_update_process_threads(void)
+{
+       while (thread_update_count > 0) {
+               spl_t   s;
+               thread_t thread = thread_update_array[--thread_update_count];
+               thread_update_array[thread_update_count] = THREAD_NULL;
+
+               s = splsched();
+               thread_lock(thread);
+               if (!(thread->state & (TH_WAIT)) && (SCHED(can_update_priority)(thread))) {
+                       SCHED(update_priority)(thread);
+               }
+               thread_unlock(thread);
+               splx(s);
+
+               thread_deallocate(thread);
+       }
+}
+

 /*
  *     Scan a runq for candidate threads.
  *
  *     Returns TRUE if retry is needed.
  */
 /*
  *     Scan a runq for candidate threads.
  *
  *     Returns TRUE if retry is needed.
  */

-static boolean_t
+boolean_t

 runq_scan(
        run_queue_t                             runq)
 {
 runq_scan(
        run_queue_t                             runq)
 {


@@ -3258,12 +5008,9 @@ runq_scan(
                while (count > 0) {
                        queue_iterate(q, thread, thread_t, links) {
                                if (            thread->sched_stamp != sched_tick               &&
                while (count > 0) {
                        queue_iterate(q, thread, thread_t, links) {
                                if (            thread->sched_stamp != sched_tick               &&

-                                               (thread->sched_mode & TH_MODE_TIMESHARE)        ) {
-                                       if (thread_update_count == THREAD_UPDATE_SIZE)
+                                               (thread->sched_mode == TH_MODE_TIMESHARE)       ) {
+                                       if (thread_update_add_thread(thread) == FALSE)

                                                return (TRUE);
                                                return (TRUE);

-
-                                       thread_update_array[thread_update_count++] = thread;
-                                       thread_reference_internal(thread);

                                }
 
                                count--;
                                }
 
                                count--;


@@ -3276,6 +5023,10 @@ runq_scan(
        return (FALSE);
 }
 
        return (FALSE);
 }
 

+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+

 static void
 thread_update_scan(void)
 {
 static void
 thread_update_scan(void)
 {


@@ -3287,12 +5038,16 @@ thread_update_scan(void)
 
        do {
                do {
 
        do {
                do {

+                       /*
+                        * TODO: in sched_traditional_use_pset_runqueue case,
+                        *  avoid scanning the same runq multiple times
+                        */

                        pset = processor->processor_set;
 
                        s = splsched();
                        pset_lock(pset);
 
                        pset = processor->processor_set;
 
                        s = splsched();
                        pset_lock(pset);
 

-                       restart_needed = runq_scan(&processor->runq);
+                       restart_needed = runq_scan(runq_for_processor(processor));

 
                        pset_unlock(pset);
                        splx(s);
 
                        pset_unlock(pset);
                        splx(s);


@@ -3302,49 +5057,126 @@ thread_update_scan(void)
 
                        thread = processor->idle_thread;
                        if (thread != THREAD_NULL && thread->sched_stamp != sched_tick) {
 
                        thread = processor->idle_thread;
                        if (thread != THREAD_NULL && thread->sched_stamp != sched_tick) {

-                               if (thread_update_count == THREAD_UPDATE_SIZE) {
+                               if (thread_update_add_thread(thread) == FALSE) {

                                        restart_needed = TRUE;
                                        break;
                                }
                                        restart_needed = TRUE;
                                        break;
                                }

-
-                               thread_update_array[thread_update_count++] = thread;
-                               thread_reference_internal(thread);

                        }
                } while ((processor = processor->processor_list) != NULL);
 
                        }
                } while ((processor = processor->processor_list) != NULL);
 

-           /*
-            *  Ok, we now have a collection of candidates -- fix them.
-            */
-           while (thread_update_count > 0) {
-                       thread = thread_update_array[--thread_update_count];
-                       thread_update_array[thread_update_count] = THREAD_NULL;
+               /* Ok, we now have a collection of candidates -- fix them. */
+               thread_update_process_threads();
+       } while (restart_needed);
+}

 
 

-                       s = splsched();
-                       thread_lock(thread);
-                       if (    !(thread->state & (TH_WAIT|TH_SUSP))    &&
-                                               thread->sched_stamp != sched_tick       )
-                               update_priority(thread);
-                       thread_unlock(thread);
-                       splx(s);
+#endif /* CONFIG_SCHED_TRADITIONAL */

 
 

-                       thread_deallocate(thread);
-           }
-       } while (restart_needed);
+boolean_t
+thread_eager_preemption(thread_t thread) 
+{
+       return ((thread->sched_flags & TH_SFLAG_EAGERPREEMPT) != 0);

 }
 }

+
+void
+thread_set_eager_preempt(thread_t thread) 
+{
+       spl_t x;
+       processor_t p;
+       ast_t ast = AST_NONE;
+
+       x = splsched();
+       p = current_processor();
+
+       thread_lock(thread);
+       thread->sched_flags |= TH_SFLAG_EAGERPREEMPT;
+
+       if (thread == current_thread()) {
+
+               ast = csw_check(p, AST_NONE);
+               thread_unlock(thread);
+               if (ast != AST_NONE) {
+                       (void) thread_block_reason(THREAD_CONTINUE_NULL, NULL, ast);
+               }
+       } else {
+               p = thread->last_processor;
+
+               if (p != PROCESSOR_NULL && p->state == PROCESSOR_RUNNING &&
+                       p->active_thread == thread) {
+                       cause_ast_check(p);
+               }

                
                

+               thread_unlock(thread);
+       }
+
+       splx(x);
+}
+
+void
+thread_clear_eager_preempt(thread_t thread) 
+{
+       spl_t x;
+
+       x = splsched();
+       thread_lock(thread);
+
+       thread->sched_flags &= ~TH_SFLAG_EAGERPREEMPT;
+       
+       thread_unlock(thread);
+       splx(x);
+}
+/*
+ * Scheduling statistics
+ */
+void
+sched_stats_handle_csw(processor_t processor, int reasons, int selfpri, int otherpri)
+{
+       struct processor_sched_statistics *stats;
+       boolean_t to_realtime = FALSE;
+       
+       stats = &processor->processor_data.sched_stats;
+       stats->csw_count++;
+
+       if (otherpri >= BASEPRI_REALTIME) {
+               stats->rt_sched_count++;
+               to_realtime = TRUE;
+       }
+
+       if ((reasons & AST_PREEMPT) != 0) {
+               stats->preempt_count++;
+
+               if (selfpri >= BASEPRI_REALTIME) {
+                       stats->preempted_rt_count++;
+               } 
+
+               if (to_realtime) {
+                       stats->preempted_by_rt_count++;
+               }
+
+       }
+}
+
+void
+sched_stats_handle_runq_change(struct runq_stats *stats, int old_count) 
+{
+       uint64_t timestamp = mach_absolute_time();
+
+       stats->count_sum += (timestamp - stats->last_change_timestamp) * old_count;
+       stats->last_change_timestamp = timestamp;
+}
+

 /*
 /*

- *     Just in case someone doesn't use the macro
+ *     For calls from assembly code

  */
  */

-#undef thread_wakeup
+#undef thread_wakeup

 void
 thread_wakeup(
 void
 thread_wakeup(

-       event_t         x);
+       event_t         x);

 
 void
 thread_wakeup(
 
 void
 thread_wakeup(

-       event_t         x)
+       event_t         x)

 {
 {

-       thread_wakeup_with_result(x, THREAD_AWAKENED);
+       thread_wakeup_with_result(x, THREAD_AWAKENED);

 }
 
 boolean_t
 }
 
 boolean_t


@@ -3353,43 +5185,15 @@ preemption_enabled(void)
        return (get_preemption_level() == 0 && ml_get_interrupts_enabled());
 }
 
        return (get_preemption_level() == 0 && ml_get_interrupts_enabled());
 }
 

-#if    DEBUG
-static boolean_t
+__assert_only static boolean_t

 thread_runnable(
        thread_t        thread)
 {
        return ((thread->state & (TH_RUN|TH_WAIT)) == TH_RUN);
 }
 thread_runnable(
        thread_t        thread)
 {
        return ((thread->state & (TH_RUN|TH_WAIT)) == TH_RUN);
 }

-#endif /* DEBUG */
-
-#if    MACH_KDB
-#include <ddb/db_output.h>
-#define        printf          kdbprintf
-void                   db_sched(void);
-
-void
-db_sched(void)
-{
-       iprintf("Scheduling Statistics:\n");
-       db_indent += 2;
-       iprintf("Thread invocations:  csw %d same %d\n",
-               c_thread_invoke_csw, c_thread_invoke_same);
-#if    MACH_COUNTERS
-       iprintf("Thread block:  calls %d\n",
-               c_thread_block_calls);
-       iprintf("Idle thread:\n\thandoff %d block %d\n",
-               c_idle_thread_handoff,
-               c_idle_thread_block);
-       iprintf("Sched thread blocks:  %d\n", c_sched_thread_block);
-#endif /* MACH_COUNTERS */
-       db_indent -= 2;
-}
-
-#include <ddb/db_output.h>
-void           db_show_thread_log(void);

 
 

-void
-db_show_thread_log(void)
-{
+static void
+sched_timer_deadline_tracking_init(void) {
+       nanoseconds_to_absolutetime(TIMER_DEADLINE_TRACKING_BIN_1_DEFAULT, &timer_deadline_tracking_bin_1);
+       nanoseconds_to_absolutetime(TIMER_DEADLINE_TRACKING_BIN_2_DEFAULT, &timer_deadline_tracking_bin_2);

 }
 }

-#endif /* MACH_KDB */