]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/kern/sched_prim.h
xnu-2782.40.9.tar.gz
[apple/xnu.git] / osfmk / kern / sched_prim.h
index b978cb01fad4a893b5a7f96ff46d63a2cbc86a0d..d7326a91c0770c3df97cc2f5b41c1be98a6dff7a 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_COPYRIGHT@
 #include <kern/clock.h>
 #include <kern/kern_types.h>
 #include <kern/thread.h>
-#include <kern/lock.h>
-#include <kern/time_out.h>     /*** ??? temp - remove me soon ***/
-#include <kern/cpu_data.h>
-#include <kern/wait_queue.h>
-
-#ifdef MACH_KERNEL_PRIVATE
+#include <sys/cdefs.h>
 
-#include <mach_ldebug.h>
-/*
- *     Exported interface to sched_prim.c.
- *     A few of these functions are actually defined in
- *     ipc_sched.c, for historical reasons.
- */
+#ifdef MACH_KERNEL_PRIVATE
 
-/* Initialize scheduler module */
+/* Initialization */
 extern void            sched_init(void);
 
-/*
- * Set up thread timeout element(s) when thread is created.
- */
-extern void            thread_timer_setup(
-                                       thread_t                thread);
+extern void            sched_startup(void);
 
-extern void            thread_timer_terminate(void);
+extern void            sched_timebase_init(void);
 
-#define thread_bind_locked(thread, processor)  \
-               (thread)->bound_processor = (processor)
-
-/*
- * Prevent a thread from restarting after it blocks interruptibly
- */
+/* Force a preemption point for a thread and wait for it to stop running */
 extern boolean_t       thread_stop( 
-                                               thread_t        thread);
+                                               thread_t        thread,
+                                               boolean_t       until_not_runnable);
 
-/*
- * wait for a thread to stop
- */
-extern boolean_t       thread_wait(
+/* Release a previous stop request */
+extern void                    thread_unstop(
                                                thread_t        thread);
 
-/* Select a thread to run on a particular processor */
-extern thread_t        thread_select(
-                                               processor_t     myprocessor);
+/* Wait for a thread to stop running */
+extern void                    thread_wait(
+                                               thread_t        thread,
+                                               boolean_t       until_not_runnable);
 
-extern void            thread_go_locked(
-                                               thread_t        thread,
-                                               int             result);
+/* Unblock thread on wake up */
+extern boolean_t       thread_unblock(
+                                               thread_t                thread,
+                                               wait_result_t   wresult);
 
-/* Stop old thread and run new thread */
-extern boolean_t thread_invoke(
-                                               thread_t        old_thread,
-                                               thread_t        new_thread,
-                                               int                     reason,
-                                               void        (*continuation)(void));
+/* Unblock and dispatch thread */
+extern kern_return_t   thread_go(
+                                                       thread_t                thread,
+                                                       wait_result_t   wresult);
 
-/* Called when current thread is given new stack */
-extern void            thread_continue(
-                                               thread_t        old_thread);
+/* Handle threads at context switch */
+extern void                    thread_dispatch(
+                                               thread_t                old_thread,
+                                               thread_t                new_thread);
 
 /* Switch directly to a particular thread */
-extern int             thread_run(
-                                               thread_t        old_thread,
-                                               void            (*continuation)(void),
-                                               thread_t        new_thread);
+extern int                     thread_run(
+                                               thread_t                        self,
+                                               thread_continue_t       continuation,
+                                               void                            *parameter,
+                                               thread_t                        new_thread);
 
-/* Dispatch a thread not on a run queue */
-extern void            thread_dispatch(
-                                               thread_t        thread);
+/* Resume thread with new stack */
+extern void                    thread_continue(
+                                               thread_t                old_thread);
 
 /* Invoke continuation */
 extern void            call_continuation(
-                                               void            (*continuation)(void));
-
-/* Compute effective priority of the specified thread */
+                                       thread_continue_t       continuation,
+                                       void                            *parameter,
+                                       wait_result_t           wresult);
+
+/* Set the current scheduled priority */
+extern void            set_sched_pri(
+                                       thread_t                thread,
+                                       int                             priority);
+
+/* Set base priority of the specified thread */
+extern void            sched_set_thread_base_priority(
+                                       thread_t                thread,
+                                       int                             priority);
+
+/* Set the thread to be categorized as 'background' */
+extern void             sched_set_thread_throttled(thread_t thread,
+                                                   boolean_t wants_throttle);
+
+/* Set the thread's true scheduling mode */
+extern void             sched_set_thread_mode(thread_t thread,
+                                              sched_mode_t mode);
+/* Demote the true scheduler mode */
+extern void             sched_thread_mode_demote(thread_t thread,
+                                                 uint32_t reason);
+/* Un-demote the true scheduler mode */
+extern void             sched_thread_mode_undemote(thread_t thread,
+                                                   uint32_t reason);
+
+/* Reset scheduled priority of thread */
 extern void            compute_priority(
-                                               thread_t        thread,
-                                               int                     resched);
+                                       thread_t                thread,
+                                       boolean_t               override_depress);
 
-/* Version of compute_priority for current thread or
- * thread being manipuldated by scheduler.
- */
+/* Adjust scheduled priority of thread during execution */
 extern void            compute_my_priority(
-                                               thread_t        thread);
+                                       thread_t                thread);
 
 /* Periodic scheduler activity */
-extern void            sched_tick_thread(void);
+extern void            sched_init_thread(void (*)(void));
 
-/* Update priority of thread that has been sleeping or suspended.
- * Used to "catch up" with the system.
- */
-extern void            update_priority(
-                                               thread_t        thread);
-
-/* Idle thread loop */
-extern void            idle_thread(void);
+/* Perform sched_tick housekeeping activities */
+extern boolean_t               can_update_priority(
+                                       thread_t                thread);
 
-/*
- *     thread_sleep_interlock:
- *
- *     Cause the current thread to wait until the specified event
- *     occurs.  The specified HW interlock is unlocked before releasing
- *     the cpu.  (This is a convenient way to sleep without manually
- *     calling assert_wait).
- */
+extern void            update_priority(
+                                                                                       thread_t                thread);
 
-#define thread_sleep_interlock(event, lock, interruptible)     \
-MACRO_BEGIN                                                                                                    \
-       assert_wait(event, interruptible);                                              \
-       interlock_unlock(lock);                                                                 \
-       thread_block((void (*)(void)) 0);                                               \
-MACRO_END
+extern void            lightweight_update_priority(
+                                                               thread_t                thread);
 
-/*
- *     Machine-dependent code must define these functions.
- */
+extern void            sched_traditional_quantum_expire(thread_t       thread);
 
-/* Start thread running */
-extern void            thread_bootstrap_return(void);
+/* Idle processor thread */
+extern void            idle_thread(void);
 
-/* Return from exception */
-extern void            thread_exception_return(void);
+extern kern_return_t   idle_thread_create(
+                                                       processor_t             processor);
 
 /* Continuation return from syscall */
 extern void     thread_syscall_return(
                         kern_return_t   ret);
 
-extern thread_t        switch_context(
-                                               thread_t        old_thread,
-                                               void            (*continuation)(void),
-                                               thread_t        new_thread);
+/* Context switch */
+extern wait_result_t   thread_block_reason(
+                                                       thread_continue_t       continuation,
+                                                       void                            *parameter,
+                                                       ast_t                           reason);
 
-/* Attach stack to thread */
-extern void            machine_kernel_stack_init(
-                                               thread_t        thread,
-                                               void            (*start_pos)(thread_t));
+/* Reschedule thread for execution */
+extern void            thread_setrun(
+                                       thread_t        thread,
+                                       integer_t       options);
 
-extern void            load_context(
-                                               thread_t        thread);
+#define SCHED_TAILQ            1
+#define SCHED_HEADQ            2
+#define SCHED_PREEMPT  4
 
-extern thread_act_t            switch_act(
-                                                       thread_act_t    act);
+extern processor_set_t task_choose_pset(
+                                                       task_t                  task);
 
-extern void            machine_switch_act(
-                                                       thread_t                thread,
-                                                       thread_act_t    old,
-                                                       thread_act_t    new,
-                                                       int                             cpu);
+/* Bind the current thread to a particular processor */
+extern processor_t             thread_bind(
+                                                       processor_t             processor);
 
-/*
- *     These functions are either defined in kern/thread.c
- *     or are defined directly by machine-dependent code.
- */
+/* Choose the best processor to run a thread */
+extern processor_t     choose_processor(
+                                                                        processor_set_t                pset,
+                                                                        processor_t                    processor,
+                                                                        thread_t                       thread);
 
-/* Allocate an activation stack */
-extern vm_offset_t     stack_alloc(thread_t thread, void (*start_pos)(thread_t));
+/* Choose a thread from a processor's priority-based runq */
+extern thread_t choose_thread_from_runq(
+                                                         processor_t           processor,
+                                                         run_queue_t           runq,
+                                                         int                           priority);
 
-/* Free an activation stack */
-extern void            stack_free(thread_t thread);
 
-/* Collect excess kernel stacks */
-extern void            stack_collect(void);
+extern void thread_quantum_init(
+                                                               thread_t thread);
 
-extern void            set_pri(
-                                       thread_t        thread,
-                                       int                     pri,
-                                       boolean_t       resched);
+extern void            run_queue_init(
+                                       run_queue_t             runq);
 
-/* Block current thread, indicating reason (Block or Quantum expiration) */
-extern int             thread_block_reason(
-                                               void            (*continuation)(void),
-                                               int             reason);
+extern thread_t        run_queue_dequeue(
+                                                         run_queue_t           runq,
+                                                         integer_t             options);
 
-/* Make thread runnable */
-extern void            thread_setrun(
-                                               thread_t        thread,
-                                               boolean_t       may_preempt,
-                                               boolean_t       tail);
-/*
- *     Flags for thread_setrun()
- */
+extern boolean_t       run_queue_enqueue(
+                                                         run_queue_t           runq,
+                                                         thread_t                      thread,
+                                                         integer_t             options);
 
-#define HEAD_Q         0               /* FALSE */
-#define TAIL_Q         1               /* TRUE */
+extern void    run_queue_remove(
+                                                                        run_queue_t            runq,
+                                                                        thread_t                       thread);
+                                                                         
 
-/* Bind thread to a particular processor */
-extern void            thread_bind(
-                                               thread_t        thread,
-                                               processor_t     processor);
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
 
-extern void            thread_mark_wait_locked(
-                                               thread_t        thread,
-                                               int                     interruptible);
+extern boolean_t        thread_update_add_thread(
+                                                 thread_t thread);
+extern void             thread_update_process_threads(void);
+extern boolean_t        runq_scan(
+                                  run_queue_t runq);
 
-#endif /* MACH_KERNEL_PRIVATE */
+void sched_traditional_timebase_init(void);
+void sched_traditional_maintenance_continue(void);
+boolean_t priority_is_urgent(
+                             int priority);
+uint32_t sched_traditional_initial_quantum_size(
+                                                thread_t thread);
+void sched_traditional_init(void);
 
-/*
- ****************** Only exported until BSD stops using ********************
- */
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
 
-/*
- * Cancel a stop and continue the thread if necessary.
- */
-extern void            thread_unstop(
+/* Remove thread from its run queue */
+extern boolean_t       thread_run_queue_remove(
                                                thread_t        thread);
 
-/* Wake up thread directly, passing result */
-extern void            clear_wait(
-                                               thread_t        thread,
-                                               int             result);
+extern void            thread_timer_expire(
+                                       void                    *thread,
+                                       void                    *p1);
 
-/* Bind thread to a particular processor */
-extern void            thread_bind(
-                                               thread_t        thread,
-                                               processor_t     processor);
+extern boolean_t       thread_eager_preemption(
+                                               thread_t thread);
 
+/* Fair Share routines */
+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
+void           sched_traditional_fairshare_init(void);
 
-/*
- * *********************   PUBLIC APIs ************************************
- */
+int                    sched_traditional_fairshare_runq_count(void);
 
-/* Set timer for current thread */
-extern void            thread_set_timer(
-                                       natural_t               interval,
-                                       natural_t               scale_factor);
+uint64_t       sched_traditional_fairshare_runq_stats_count_sum(void);
 
-extern void            thread_set_timer_deadline(
-                                       AbsoluteTime    deadline);
+void           sched_traditional_fairshare_enqueue(thread_t thread);
 
-extern void            thread_cancel_timer(void);
+thread_t       sched_traditional_fairshare_dequeue(void);
 
-/*
- * thread_stop a thread then wait for it to stop (both of the above)
- */
-extern boolean_t       thread_stop_wait(
-                                               thread_t        thread);
+boolean_t      sched_traditional_fairshare_queue_remove(thread_t thread);
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
 
-/* Declare thread will wait on a particular event */
-extern void            assert_wait(
-                                               event_t         event,
-                                               int             interruptflag);
+#if defined(CONFIG_SCHED_GRRR)
+void           sched_grrr_fairshare_init(void);
 
-/* Assert that the thread intends to wait for a timeout */
-extern void            assert_wait_timeout(
-                                               natural_t       msecs,
-                                               int             interruptflags);
+int                    sched_grrr_fairshare_runq_count(void);
 
-/* Wake up thread (or threads) waiting on a particular event */
-extern void            thread_wakeup_prim(
-                                               event_t         event,
-                                               boolean_t       one_thread,
-                                               int             result);
+uint64_t       sched_grrr_fairshare_runq_stats_count_sum(void);
+
+void           sched_grrr_fairshare_enqueue(thread_t thread);
+
+thread_t       sched_grrr_fairshare_dequeue(void);
+
+boolean_t      sched_grrr_fairshare_queue_remove(thread_t thread);
+#endif
+
+extern boolean_t sched_generic_direct_dispatch_to_idle_processors;
+
+/* Set the maximum interrupt level for the thread */
+__private_extern__ wait_interrupt_t thread_interrupt_level(
+                                               wait_interrupt_t interruptible);
+
+__private_extern__ wait_result_t thread_mark_wait_locked(
+                                               thread_t                 thread,
+                                               wait_interrupt_t interruptible);
+
+/* Wake up locked thread directly, passing result */
+__private_extern__ kern_return_t clear_wait_internal(
+                                               thread_t                thread,
+                                               wait_result_t   result);
+
+extern void sched_stats_handle_csw(
+                                                       processor_t processor, 
+                                                       int reasons, 
+                                                       int selfpri, 
+                                                       int otherpri);
+
+extern void sched_stats_handle_runq_change(
+                                                                       struct runq_stats *stats, 
+                                                                       int old_count);
+
+
+
+#define        SCHED_STATS_CSW(processor, reasons, selfpri, otherpri)          \
+do {                                                           \
+       if (__builtin_expect(sched_stats_active, 0)) {  \
+               sched_stats_handle_csw((processor),             \
+                               (reasons), (selfpri), (otherpri));      \
+       }                                                       \
+} while (0) 
+
+
+#define SCHED_STATS_RUNQ_CHANGE(stats, old_count)              \
+do {                                                           \
+       if (__builtin_expect(sched_stats_active, 0)) {  \
+               sched_stats_handle_runq_change((stats),         \
+                                                               (old_count));           \
+       }                                                       \
+} while (0) 
+
+#define THREAD_URGENCY_NONE            0       /* indicates that there is no currently runnable */
+#define THREAD_URGENCY_BACKGROUND      1       /* indicates that the thread is marked as a "background" thread */
+#define THREAD_URGENCY_NORMAL          2       /* indicates that the thread is marked as a "normal" thread */
+#define THREAD_URGENCY_REAL_TIME       3       /* indicates that the thread is marked as a "real-time" or urgent thread */
+#define        THREAD_URGENCY_MAX              4       /* Marker */
+/* Returns the "urgency" of a thread (provided by scheduler) */
+extern int     thread_get_urgency(
+                                       thread_t        thread,
+                                       uint64_t        *rt_period,
+                                       uint64_t        *rt_deadline);
+
+/* Tells the "urgency" of the just scheduled thread (provided by CPU PM) */
+extern void    thread_tell_urgency(
+                                       int             urgency,
+                                       uint64_t        rt_period,
+                                       uint64_t        rt_deadline,
+                                   thread_t nthread);
+
+/* Tells if there are "active" RT threads in the system (provided by CPU PM) */
+extern void    active_rt_threads(
+                                       boolean_t       active);
+
+#endif /* MACH_KERNEL_PRIVATE */
+
+__BEGIN_DECLS
 
-/* Block current thread (Block reason) */
-extern int             thread_block(
-                                               void            (*continuation)(void));
+#ifdef XNU_KERNEL_PRIVATE
 
+extern boolean_t               assert_wait_possible(void);
+
+/* Toggles a global override to turn off CPU Throttling */
+#define CPU_THROTTLE_DISABLE   0
+#define CPU_THROTTLE_ENABLE    1
+extern void    sys_override_cpu_throttle(int flag);
 
 /*
- *     Routines defined as macros
+ ****************** Only exported until BSD stops using ********************
  */
 
+/* Wake up thread directly, passing result */
+extern kern_return_t clear_wait(
+                                               thread_t                thread,
+                                               wait_result_t   result);
+
+/* Start thread running */
+extern void            thread_bootstrap_return(void);
+
+/* Return from exception (BSD-visible interface) */
+extern void            thread_exception_return(void) __dead2;
+
+#endif /* XNU_KERNEL_PRIVATE */
+
+/* Context switch */
+extern wait_result_t   thread_block(
+                                                       thread_continue_t       continuation);
+
+extern wait_result_t   thread_block_parameter(
+                                                       thread_continue_t       continuation,
+                                                       void                            *parameter);
+
+/* Declare thread will wait on a particular event */
+extern wait_result_t   assert_wait(
+                                                       event_t                         event,
+                                                       wait_interrupt_t        interruptible);
+
+/* Assert that the thread intends to wait with a timeout */
+extern wait_result_t   assert_wait_timeout(
+                                                       event_t                         event,
+                                                       wait_interrupt_t        interruptible,
+                                                       uint32_t                        interval,
+                                                       uint32_t                        scale_factor);
+
+/* Assert that the thread intends to wait with an urgency, timeout and leeway */
+extern 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);
+
+extern wait_result_t   assert_wait_deadline(
+                                                       event_t                         event,
+                                                       wait_interrupt_t        interruptible,
+                                                       uint64_t                        deadline);
+
+/* Assert that the thread intends to wait with an urgency, deadline, and leeway */
+extern 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);
+
+/* Wake up thread (or threads) waiting on a particular event */
+extern kern_return_t   thread_wakeup_prim(
+                                                       event_t                         event,
+                                                       boolean_t                       one_thread,
+                                                       wait_result_t                   result);
+
+extern kern_return_t    thread_wakeup_prim_internal(
+                                                       event_t                         event,
+                                                       boolean_t                       one_thread,
+                                                       wait_result_t                   result,
+                                                       int                             priority);
+
+
 #define thread_wakeup(x)                                       \
                        thread_wakeup_prim((x), FALSE, THREAD_AWAKENED)
 #define thread_wakeup_with_result(x, z)                \
@@ -334,37 +458,232 @@ extern int               thread_block(
 #define thread_wakeup_one(x)                           \
                        thread_wakeup_prim((x), TRUE, THREAD_AWAKENED)
 
-/*
- *     thread_sleep_mutex:
- *
- *     Cause the current thread to wait until the specified event
- *     occurs.  The specified mutex is unlocked before releasing
- *     the cpu.  (This is a convenient way to sleep without manually
- *     calling assert_wait).
- */
+#ifdef MACH_KERNEL_PRIVATE
+#define thread_wakeup_one_with_pri(x, pri)                              \
+                       thread_wakeup_prim_internal((x), TRUE, THREAD_AWAKENED, pri)
+#endif
 
-#define thread_sleep_mutex(event, lock, interruptible) \
-MACRO_BEGIN                                                                                            \
-       assert_wait(event, interruptible);                                      \
-       mutex_unlock(lock);                                                                     \
-       thread_block((void (*)(void)) 0);                                       \
-MACRO_END
+extern boolean_t               preemption_enabled(void);
+
+#ifdef MACH_KERNEL_PRIVATE
 
 /*
- *     thread_sleep_simple_lock:
- *
- *     Cause the current thread to wait until the specified event
- *     occurs.  The specified simple_lock is unlocked before releasing
- *     the cpu.  (This is a convenient way to sleep without manually
- *     calling assert_wait).
+ * Scheduler algorithm indirection. If only one algorithm is
+ * enabled at compile-time, a direction function call is used.
+ * If more than one is enabled, calls are dispatched through
+ * a function pointer table.
  */
 
-#define thread_sleep_simple_lock(event, lock, interruptible)   \
-MACRO_BEGIN                                                                                                            \
-       assert_wait(event, interruptible);                                                      \
-       simple_unlock(lock);                                                                            \
-       thread_block((void (*)(void)) 0);                                                       \
-MACRO_END
+#if   !defined(CONFIG_SCHED_TRADITIONAL) && !defined(CONFIG_SCHED_PROTO) && !defined(CONFIG_SCHED_GRRR) && !defined(CONFIG_SCHED_MULTIQ)
+#error Enable at least one scheduler algorithm in osfmk/conf/MASTER.XXX
+#endif
+
+#define SCHED(f) (sched_current_dispatch->f)
+
+struct sched_dispatch_table {
+       void    (*init)(void);                          /* Init global state */
+       void    (*timebase_init)(void);         /* Timebase-dependent initialization */
+       void    (*processor_init)(processor_t processor);       /* Per-processor scheduler init */
+       void    (*pset_init)(processor_set_t pset);     /* Per-processor set scheduler init */
+       
+       void    (*maintenance_continuation)(void);      /* Function called regularly */
+       
+       /*
+        * Choose a thread of greater or equal priority from the per-processor
+        * runqueue for timeshare/fixed threads
+        */
+       thread_t        (*choose_thread)(
+                                                                 processor_t           processor,
+                                                                 int                           priority,
+                                                                 ast_t reason);
+       
+       /*
+        * Steal a thread from another processor in the pset so that it can run
+        * immediately
+        */
+       thread_t        (*steal_thread)(
+                                                               processor_set_t         pset);
+       
+       /*
+        * Recalculate sched_pri based on base priority, past running time,
+        * and scheduling class.
+        */
+       void            (*compute_priority)(
+                                        thread_t       thread,
+                                        boolean_t                      override_depress);
+       
+       /*
+        * Pick the best processor for a thread (any kind of thread) to run on.
+        */
+       processor_t     (*choose_processor)(
+                                                                                processor_set_t                pset,
+                                                                                processor_t                    processor,
+                                                                                thread_t                       thread);
+       /*
+        * Enqueue a timeshare or fixed priority thread onto the per-processor
+        * runqueue
+        */
+       boolean_t (*processor_enqueue)(
+                                                                processor_t                    processor,
+                                                                thread_t                       thread,
+                                                                integer_t                      options);
+       
+       /* Migrate threads away in preparation for processor shutdown */
+       void (*processor_queue_shutdown)(
+                                                                        processor_t                    processor);
+       
+       /* Remove the specific thread from the per-processor runqueue */
+       boolean_t       (*processor_queue_remove)(
+                                                                       processor_t             processor,
+                                                                       thread_t                thread);
+       
+       /*
+        * Does the per-processor runqueue have any timeshare or fixed priority
+        * threads on it? Called without pset lock held, so should
+        * not assume immutability while executing.
+        */
+       boolean_t       (*processor_queue_empty)(processor_t            processor);
+       
+       /*
+        * Would this priority trigger an urgent preemption if it's sitting
+        * on the per-processor runqueue?
+        */
+       boolean_t       (*priority_is_urgent)(int priority);
+       
+       /*
+        * Does the per-processor runqueue contain runnable threads that
+        * should cause the currently-running thread to be preempted?
+        */
+       ast_t           (*processor_csw_check)(processor_t processor);
+       
+       /*
+        * Does the per-processor runqueue contain a runnable thread
+        * of > or >= priority, as a preflight for choose_thread() or other
+        * thread selection
+        */
+       boolean_t       (*processor_queue_has_priority)(processor_t             processor,
+                                                                                               int                             priority,
+                                                                                               boolean_t               gte);
+       
+       /* Quantum size for the specified non-realtime thread. */
+       uint32_t        (*initial_quantum_size)(thread_t thread);
+       
+       /* Scheduler mode for a new thread */
+       sched_mode_t    (*initial_thread_sched_mode)(task_t parent_task);
+       
+       /*
+        * Is it safe to call update_priority, which may change a thread's
+        * runqueue or other state. This can be used to throttle changes
+        * to dynamic priority.
+        */
+       boolean_t       (*can_update_priority)(thread_t thread);
+
+       /*
+        * Update both scheduled priority and other persistent state.
+        * Side effects may including migration to another processor's runqueue.
+        */
+       void            (*update_priority)(thread_t thread);
+       
+       /* Lower overhead update to scheduled priority and state. */
+       void            (*lightweight_update_priority)(thread_t thread);
+       
+       /* Callback for non-realtime threads when the quantum timer fires */
+       void            (*quantum_expire)(thread_t thread);
+       
+       /*
+        * Even though we could continue executing on this processor, does the
+        * topology (SMT, for instance) indicate that a better processor could be
+        * chosen
+        */
+       boolean_t       (*should_current_thread_rechoose_processor)(processor_t                 processor);
+    
+       /*
+        * Runnable threads on per-processor runqueue. Should only
+        * be used for relative comparisons of load between processors.
+        */
+       int                     (*processor_runq_count)(processor_t     processor);
+       
+       /* Aggregate runcount statistics for per-processor runqueue */
+    uint64_t    (*processor_runq_stats_count_sum)(processor_t   processor);
+       
+       /* Initialize structures to track demoted fairshare threads */
+       void            (*fairshare_init)(void);
+       
+       /* Number of runnable fairshare threads */
+       int                     (*fairshare_runq_count)(void);
+       
+       /* Aggregate runcount statistics for fairshare runqueue */
+       uint64_t        (*fairshare_runq_stats_count_sum)(void);
+       
+       void            (*fairshare_enqueue)(thread_t thread);
+       
+       thread_t        (*fairshare_dequeue)(void);
+
+       boolean_t       (*fairshare_queue_remove)(thread_t thread);
+
+       boolean_t       (*processor_bound_count)(processor_t processor);
+
+       void            (*thread_update_scan)(void);
+
+       /*
+       * Use processor->next_thread to pin a thread to an idle
+       * processor. If FALSE, threads are enqueued and can
+       * be stolen by other processors.
+       */
+       boolean_t   direct_dispatch_to_idle_processors;
+};
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+#define kSchedTraditionalString "traditional"
+#define kSchedTraditionalWithPsetRunqueueString "traditional_with_pset_runqueue"
+extern const struct sched_dispatch_table sched_traditional_dispatch;
+extern const struct sched_dispatch_table sched_traditional_with_pset_runqueue_dispatch;
+#endif
+
+#if defined(CONFIG_SCHED_MULTIQ)
+extern const struct sched_dispatch_table sched_multiq_dispatch;
+#define kSchedMultiQString "multiq"
+extern const struct sched_dispatch_table sched_dualq_dispatch;
+#define kSchedDualQString "dualq"
+#endif
+
+#if defined(CONFIG_SCHED_PROTO)
+#define kSchedProtoString "proto"
+extern const struct sched_dispatch_table sched_proto_dispatch;
+#endif
+
+#if defined(CONFIG_SCHED_GRRR)
+#define kSchedGRRRString "grrr"
+extern const struct sched_dispatch_table sched_grrr_dispatch;
+#endif
 
+/*
+ * It is an error to invoke any scheduler-related code
+ * before this is set up
+ */
+enum sched_enum {
+       sched_enum_unknown = 0,
+#if defined(CONFIG_SCHED_TRADITIONAL)
+       sched_enum_traditional = 1,
+       sched_enum_traditional_with_pset_runqueue = 2,
+#endif
+#if defined(CONFIG_SCHED_PROTO)
+       sched_enum_proto = 3,
+#endif
+#if defined(CONFIG_SCHED_GRRR)
+       sched_enum_grrr = 4,
+#endif
+#if defined(CONFIG_SCHED_MULTIQ)
+       sched_enum_multiq = 5,
+       sched_enum_dualq = 6,
+#endif
+       sched_enum_max = 7,
+};
+
+extern const struct sched_dispatch_table *sched_current_dispatch;
+
+#endif /* MACH_KERNEL_PRIVATE */
+
+__END_DECLS
 
 #endif /* _KERN_SCHED_PRIM_H_ */