osfmk/kern/sched_prim.h

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  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58 /*
  59  *      File:   sched_prim.h
  60  *      Author: David Golub
  61  *
  62  *      Scheduling primitive definitions file
  63  *
  64  */
  65
  66 #ifndef _KERN_SCHED_PRIM_H_
  67 #define _KERN_SCHED_PRIM_H_
  68
  69 #include <mach/boolean.h>
  70 #include <mach/machine/vm_types.h>
  71 #include <mach/kern_return.h>
  72 #include <kern/clock.h>
  73 #include <kern/kern_types.h>
  74 #include <kern/thread.h>
  75 #include <sys/cdefs.h>
  76 #include <kern/block_hint.h>
  77
  78 #ifdef  MACH_KERNEL_PRIVATE
  79
  80 #include <kern/sched_urgency.h>
  81 #include <kern/thread_group.h>
  82
  83 /* Initialization */
  84 extern void             sched_init(void);
  85
  86 extern void             sched_startup(void);
  87
  88 extern void             sched_timebase_init(void);
  89
  90 extern void             pset_rt_init(processor_set_t pset);
  91
  92 extern void             sched_rtglobal_init(processor_set_t pset);
  93
  94 extern rt_queue_t       sched_rtglobal_runq(processor_set_t pset);
  95
  96 extern void             sched_rtglobal_queue_shutdown(processor_t processor);
  97
  98 extern int64_t          sched_rtglobal_runq_count_sum(void);
  99
 100 extern void             sched_check_spill(processor_set_t pset, thread_t thread);
 101
 102 extern bool             sched_thread_should_yield(processor_t processor, thread_t thread);
 103
 104 extern bool             sched_steal_thread_DISABLED(processor_set_t pset);
 105 extern bool             sched_steal_thread_enabled(processor_set_t pset);
 106
 107 /* Force a preemption point for a thread and wait for it to stop running */
 108 extern boolean_t        thread_stop(
 109         thread_t        thread,
 110         boolean_t       until_not_runnable);
 111
 112 /* Release a previous stop request */
 113 extern void                     thread_unstop(
 114         thread_t        thread);
 115
 116 /* Wait for a thread to stop running */
 117 extern void                     thread_wait(
 118         thread_t        thread,
 119         boolean_t       until_not_runnable);
 120
 121 /* Unblock thread on wake up */
 122 extern boolean_t        thread_unblock(
 123         thread_t                thread,
 124         wait_result_t   wresult);
 125
 126 /* Unblock and dispatch thread */
 127 extern kern_return_t    thread_go(
 128         thread_t                thread,
 129         wait_result_t   wresult);
 130
 131 /* Handle threads at context switch */
 132 extern void                     thread_dispatch(
 133         thread_t                old_thread,
 134         thread_t                new_thread);
 135
 136 /* Switch directly to a particular thread */
 137 extern int                      thread_run(
 138         thread_t                        self,
 139         thread_continue_t       continuation,
 140         void                            *parameter,
 141         thread_t                        new_thread);
 142
 143 /* Resume thread with new stack */
 144 extern __dead2 void     thread_continue(thread_t old_thread);
 145
 146 /* Invoke continuation */
 147 extern __dead2 void     call_continuation(
 148         thread_continue_t       continuation,
 149         void                    *parameter,
 150         wait_result_t           wresult,
 151         boolean_t               enable_interrupts);
 152
 153 /*
 154  * Flags that can be passed to set_sched_pri
 155  * to skip side effects
 156  */
 157 __options_decl(set_sched_pri_options_t, uint32_t, {
 158         SETPRI_DEFAULT  = 0x0,
 159         SETPRI_LAZY     = 0x1,  /* Avoid setting AST flags or sending IPIs */
 160 });
 161
 162 /* Set the current scheduled priority */
 163 extern void set_sched_pri(
 164         thread_t      thread,
 165         int           priority,
 166         set_sched_pri_options_t options);
 167
 168 /* Set base priority of the specified thread */
 169 extern void             sched_set_thread_base_priority(
 170         thread_t                thread,
 171         int                             priority);
 172
 173 /* Set absolute base priority of the specified thread */
 174 extern void             sched_set_kernel_thread_priority(
 175         thread_t                thread,
 176         int                             priority);
 177
 178
 179 /* Set the thread's true scheduling mode */
 180 extern void             sched_set_thread_mode(thread_t thread,
 181     sched_mode_t mode);
 182 /* Demote the true scheduler mode */
 183 extern void             sched_thread_mode_demote(thread_t thread,
 184     uint32_t reason);
 185 /* Un-demote the true scheduler mode */
 186 extern void             sched_thread_mode_undemote(thread_t thread,
 187     uint32_t reason);
 188
 189 extern void sched_thread_promote_reason(thread_t thread, uint32_t reason, uintptr_t trace_obj);
 190 extern void sched_thread_unpromote_reason(thread_t thread, uint32_t reason, uintptr_t trace_obj);
 191
 192 /* Re-evaluate base priority of thread (thread locked) */
 193 void thread_recompute_priority(thread_t thread);
 194
 195 /* Re-evaluate scheduled priority of thread (thread locked) */
 196 extern void thread_recompute_sched_pri(
 197         thread_t thread,
 198         set_sched_pri_options_t options);
 199
 200 /* Periodic scheduler activity */
 201 extern void             sched_init_thread(void (*)(void));
 202
 203 /* Perform sched_tick housekeeping activities */
 204 extern boolean_t                can_update_priority(
 205         thread_t                thread);
 206
 207 extern void             update_priority(
 208         thread_t                thread);
 209
 210 extern void             lightweight_update_priority(
 211         thread_t                thread);
 212
 213 extern void             sched_default_quantum_expire(thread_t thread);
 214
 215 /* Idle processor thread continuation */
 216 extern void             idle_thread(
 217         void*           parameter,
 218         wait_result_t   result);
 219
 220 extern kern_return_t    idle_thread_create(
 221         processor_t             processor);
 222
 223 /* Continuation return from syscall */
 224 extern void     thread_syscall_return(
 225         kern_return_t   ret);
 226
 227 /* Context switch */
 228 extern wait_result_t    thread_block_reason(
 229         thread_continue_t       continuation,
 230         void                            *parameter,
 231         ast_t                           reason);
 232
 233 __options_decl(sched_options_t, uint32_t, {
 234         SCHED_NONE      = 0x0,
 235         SCHED_TAILQ     = 0x1,
 236         SCHED_HEADQ     = 0x2,
 237         SCHED_PREEMPT   = 0x4,
 238         SCHED_REBALANCE = 0x8,
 239 });
 240
 241 /* Reschedule thread for execution */
 242 extern void             thread_setrun(
 243         thread_t        thread,
 244         sched_options_t options);
 245
 246 extern processor_set_t  task_choose_pset(
 247         task_t                  task);
 248
 249 /* Bind the current thread to a particular processor */
 250 extern processor_t              thread_bind(
 251         processor_t             processor);
 252
 253 /* Choose the best processor to run a thread */
 254 extern processor_t      choose_processor(
 255         processor_set_t                pset,
 256         processor_t                    processor,
 257         thread_t                       thread);
 258
 259 extern void sched_SMT_balance(
 260         processor_t processor,
 261         processor_set_t pset);
 262
 263 extern void thread_quantum_init(
 264         thread_t thread);
 265
 266 extern void             run_queue_init(
 267         run_queue_t             runq);
 268
 269 extern thread_t run_queue_dequeue(
 270         run_queue_t           runq,
 271         sched_options_t       options);
 272
 273 extern boolean_t        run_queue_enqueue(
 274         run_queue_t           runq,
 275         thread_t              thread,
 276         sched_options_t       options);
 277
 278 extern void     run_queue_remove(
 279         run_queue_t            runq,
 280         thread_t                       thread);
 281
 282 extern thread_t run_queue_peek(
 283         run_queue_t            runq);
 284
 285 struct sched_update_scan_context {
 286         uint64_t        earliest_bg_make_runnable_time;
 287         uint64_t        earliest_normal_make_runnable_time;
 288         uint64_t        earliest_rt_make_runnable_time;
 289 };
 290 typedef struct sched_update_scan_context *sched_update_scan_context_t;
 291
 292 extern void             sched_rtglobal_runq_scan(sched_update_scan_context_t scan_context);
 293
 294 extern void sched_pset_made_schedulable(
 295         processor_t processor,
 296         processor_set_t pset,
 297         boolean_t drop_lock);
 298
 299 /*
 300  * Enum to define various events which need IPIs. The IPI policy
 301  * engine decides what kind of IPI to use based on destination
 302  * processor state, thread and one of the following scheduling events.
 303  */
 304 typedef enum {
 305         SCHED_IPI_EVENT_BOUND_THR   = 0x1,
 306         SCHED_IPI_EVENT_PREEMPT     = 0x2,
 307         SCHED_IPI_EVENT_SMT_REBAL   = 0x3,
 308         SCHED_IPI_EVENT_SPILL       = 0x4,
 309         SCHED_IPI_EVENT_REBALANCE   = 0x5,
 310 } sched_ipi_event_t;
 311
 312
 313 /* Enum to define various IPI types used by the scheduler */
 314 typedef enum {
 315         SCHED_IPI_NONE              = 0x0,
 316         SCHED_IPI_IMMEDIATE         = 0x1,
 317         SCHED_IPI_IDLE              = 0x2,
 318         SCHED_IPI_DEFERRED          = 0x3,
 319 } sched_ipi_type_t;
 320
 321 /* The IPI policy engine behaves in the following manner:
 322  * - All scheduler events which need an IPI invoke sched_ipi_action() with
 323  *   the appropriate destination processor, thread and event.
 324  * - sched_ipi_action() performs basic checks, invokes the scheduler specific
 325  *   ipi_policy routine and sets pending_AST bits based on the result.
 326  * - Once the pset lock is dropped, the scheduler invokes sched_ipi_perform()
 327  *   routine which actually sends the appropriate IPI to the destination core.
 328  */
 329 extern sched_ipi_type_t sched_ipi_action(processor_t dst, thread_t thread,
 330     boolean_t dst_idle, sched_ipi_event_t event);
 331 extern void sched_ipi_perform(processor_t dst, sched_ipi_type_t ipi);
 332
 333 /* sched_ipi_policy() is the global default IPI policy for all schedulers */
 334 extern sched_ipi_type_t sched_ipi_policy(processor_t dst, thread_t thread,
 335     boolean_t dst_idle, sched_ipi_event_t event);
 336
 337 /* sched_ipi_deferred_policy() is the global default deferred IPI policy for all schedulers */
 338 extern sched_ipi_type_t sched_ipi_deferred_policy(processor_set_t pset,
 339     processor_t dst, sched_ipi_event_t event);
 340
 341 #if defined(CONFIG_SCHED_TIMESHARE_CORE)
 342
 343 extern boolean_t        thread_update_add_thread(thread_t thread);
 344 extern void             thread_update_process_threads(void);
 345 extern boolean_t        runq_scan(run_queue_t runq, sched_update_scan_context_t scan_context);
 346
 347 extern void sched_timeshare_init(void);
 348 extern void sched_timeshare_timebase_init(void);
 349 extern void sched_timeshare_maintenance_continue(void);
 350
 351 extern boolean_t priority_is_urgent(int priority);
 352 extern uint32_t sched_timeshare_initial_quantum_size(thread_t thread);
 353
 354 extern int sched_compute_timeshare_priority(thread_t thread);
 355
 356 #endif /* CONFIG_SCHED_TIMESHARE_CORE */
 357
 358 /* Remove thread from its run queue */
 359 extern boolean_t        thread_run_queue_remove(thread_t thread);
 360 thread_t thread_run_queue_remove_for_handoff(thread_t thread);
 361
 362 /* Put a thread back in the run queue after being yanked */
 363 extern void thread_run_queue_reinsert(thread_t thread, sched_options_t options);
 364
 365 extern void             thread_timer_expire(
 366         void                    *thread,
 367         void                    *p1);
 368
 369 extern boolean_t        thread_eager_preemption(
 370         thread_t thread);
 371
 372 extern boolean_t sched_generic_direct_dispatch_to_idle_processors;
 373
 374 /* Set the maximum interrupt level for the thread */
 375 __private_extern__ wait_interrupt_t thread_interrupt_level(
 376         wait_interrupt_t interruptible);
 377
 378 __private_extern__ wait_result_t thread_mark_wait_locked(
 379         thread_t                 thread,
 380         wait_interrupt_t interruptible);
 381
 382 /* Wake up locked thread directly, passing result */
 383 __private_extern__ kern_return_t clear_wait_internal(
 384         thread_t                thread,
 385         wait_result_t   result);
 386
 387 extern void sched_stats_handle_csw(
 388         processor_t processor,
 389         int reasons,
 390         int selfpri,
 391         int otherpri);
 392
 393 extern void sched_stats_handle_runq_change(
 394         struct runq_stats *stats,
 395         int old_count);
 396
 397
 398 #if DEBUG
 399
 400 #define SCHED_STATS_CSW(processor, reasons, selfpri, otherpri)          \
 401 do {                                                            \
 402         if (__builtin_expect(sched_stats_active, 0)) {  \
 403                 sched_stats_handle_csw((processor),             \
 404                                 (reasons), (selfpri), (otherpri));      \
 405         }                                                       \
 406 } while (0)
 407
 408
 409 #define SCHED_STATS_RUNQ_CHANGE(stats, old_count)               \
 410 do {                                                            \
 411         if (__builtin_expect(sched_stats_active, 0)) {  \
 412                 sched_stats_handle_runq_change((stats),         \
 413                                                                 (old_count));           \
 414         }                                                       \
 415 } while (0)
 416
 417 #else /* DEBUG */
 418
 419 #define SCHED_STATS_CSW(processor, reasons, selfpri, otherpri) do { }while(0)
 420 #define SCHED_STATS_RUNQ_CHANGE(stats, old_count) do { }while(0)
 421
 422 #endif /* DEBUG */
 423
 424 extern uint32_t sched_debug_flags;
 425 #define SCHED_DEBUG_FLAG_PLATFORM_TRACEPOINTS   0x00000001
 426 #define SCHED_DEBUG_FLAG_CHOOSE_PROCESSOR_TRACEPOINTS   0x00000002
 427
 428 #define SCHED_DEBUG_PLATFORM_KERNEL_DEBUG_CONSTANT(...) do {                                            \
 429                 if (__improbable(sched_debug_flags & SCHED_DEBUG_FLAG_PLATFORM_TRACEPOINTS)) { \
 430                         KERNEL_DEBUG_CONSTANT(__VA_ARGS__);                                                     \
 431                 }                                                                                                                               \
 432         } while(0)
 433
 434 #define SCHED_DEBUG_CHOOSE_PROCESSOR_KERNEL_DEBUG_CONSTANT(...) do {                                            \
 435                 if (__improbable(sched_debug_flags & SCHED_DEBUG_FLAG_CHOOSE_PROCESSOR_TRACEPOINTS)) { \
 436                         KERNEL_DEBUG_CONSTANT(__VA_ARGS__);                                                     \
 437                 }                                                                                                                               \
 438         } while(0)
 439
 440 /* Tells if there are "active" RT threads in the system (provided by CPU PM) */
 441 extern void     active_rt_threads(
 442         boolean_t       active);
 443
 444 /* Returns the perfcontrol attribute for the thread */
 445 extern perfcontrol_class_t thread_get_perfcontrol_class(
 446         thread_t        thread);
 447
 448 /* Generic routine for Non-AMP schedulers to calculate parallelism */
 449 extern uint32_t sched_qos_max_parallelism(int qos, uint64_t options);
 450
 451 #endif /* MACH_KERNEL_PRIVATE */
 452
 453 __BEGIN_DECLS
 454
 455 #ifdef  XNU_KERNEL_PRIVATE
 456
 457 /* Toggles a global override to turn off CPU Throttling */
 458 extern void     sys_override_cpu_throttle(boolean_t enable_override);
 459
 460 /*
 461  ****************** Only exported until BSD stops using ********************
 462  */
 463
 464 extern void                     thread_vm_bind_group_add(void);
 465
 466 /* Wake up thread directly, passing result */
 467 extern kern_return_t clear_wait(
 468         thread_t                thread,
 469         wait_result_t   result);
 470
 471 /* Start thread running */
 472 extern void             thread_bootstrap_return(void) __attribute__((noreturn));
 473
 474 /* Return from exception (BSD-visible interface) */
 475 extern void             thread_exception_return(void) __dead2;
 476
 477 #define SCHED_STRING_MAX_LENGTH (48)
 478 /* String declaring the name of the current scheduler */
 479 extern char sched_string[SCHED_STRING_MAX_LENGTH];
 480
 481 /* Attempt to context switch to a specific runnable thread */
 482 extern wait_result_t thread_handoff_deallocate(thread_t thread);
 483
 484 __attribute__((nonnull(1, 2)))
 485 extern void thread_handoff_parameter(thread_t thread,
 486     thread_continue_t continuation, void *parameter) __dead2;
 487
 488 extern struct waitq     *assert_wait_queue(event_t event);
 489
 490 extern kern_return_t thread_wakeup_one_with_pri(event_t event, int priority);
 491
 492 extern thread_t thread_wakeup_identify(event_t event, int priority);
 493
 494 #endif  /* XNU_KERNEL_PRIVATE */
 495
 496 #ifdef KERNEL_PRIVATE
 497 /* Set pending block hint for a particular object before we go into a wait state */
 498 extern void             thread_set_pending_block_hint(
 499         thread_t                        thread,
 500         block_hint_t                    block_hint);
 501
 502 #define QOS_PARALLELISM_COUNT_LOGICAL   0x1
 503 #define QOS_PARALLELISM_REALTIME        0x2
 504 extern uint32_t qos_max_parallelism(int qos, uint64_t options);
 505 #endif /* KERNEL_PRIVATE */
 506
 507 #if XNU_KERNEL_PRIVATE
 508 extern void             thread_yield_with_continuation(
 509         thread_continue_t       continuation,
 510         void                            *parameter) __dead2;
 511 #endif
 512
 513 /* Context switch */
 514 extern wait_result_t    thread_block(
 515         thread_continue_t       continuation);
 516
 517 extern wait_result_t    thread_block_parameter(
 518         thread_continue_t       continuation,
 519         void                            *parameter);
 520
 521 /* Declare thread will wait on a particular event */
 522 extern wait_result_t    assert_wait(
 523         event_t                         event,
 524         wait_interrupt_t        interruptible);
 525
 526 /* Assert that the thread intends to wait with a timeout */
 527 extern wait_result_t    assert_wait_timeout(
 528         event_t                         event,
 529         wait_interrupt_t        interruptible,
 530         uint32_t                        interval,
 531         uint32_t                        scale_factor);
 532
 533 /* Assert that the thread intends to wait with an urgency, timeout and leeway */
 534 extern wait_result_t    assert_wait_timeout_with_leeway(
 535         event_t                         event,
 536         wait_interrupt_t        interruptible,
 537         wait_timeout_urgency_t  urgency,
 538         uint32_t                        interval,
 539         uint32_t                        leeway,
 540         uint32_t                        scale_factor);
 541
 542 extern wait_result_t    assert_wait_deadline(
 543         event_t                         event,
 544         wait_interrupt_t        interruptible,
 545         uint64_t                        deadline);
 546
 547 /* Assert that the thread intends to wait with an urgency, deadline, and leeway */
 548 extern wait_result_t    assert_wait_deadline_with_leeway(
 549         event_t                         event,
 550         wait_interrupt_t        interruptible,
 551         wait_timeout_urgency_t  urgency,
 552         uint64_t                        deadline,
 553         uint64_t                        leeway);
 554
 555 /* Wake up thread (or threads) waiting on a particular event */
 556 extern kern_return_t    thread_wakeup_prim(
 557         event_t                         event,
 558         boolean_t                       one_thread,
 559         wait_result_t                   result);
 560
 561 #define thread_wakeup(x)                                        \
 562                         thread_wakeup_prim((x), FALSE, THREAD_AWAKENED)
 563 #define thread_wakeup_with_result(x, z)         \
 564                         thread_wakeup_prim((x), FALSE, (z))
 565 #define thread_wakeup_one(x)                            \
 566                         thread_wakeup_prim((x), TRUE, THREAD_AWAKENED)
 567
 568 /* Wakeup the specified thread if it is waiting on this event */
 569 extern kern_return_t thread_wakeup_thread(event_t event, thread_t thread);
 570
 571 extern boolean_t preemption_enabled(void);
 572
 573 #ifdef MACH_KERNEL_PRIVATE
 574
 575 /*
 576  * Scheduler algorithm indirection. If only one algorithm is
 577  * enabled at compile-time, a direction function call is used.
 578  * If more than one is enabled, calls are dispatched through
 579  * a function pointer table.
 580  */
 581
 582 #if   !defined(CONFIG_SCHED_TRADITIONAL) && !defined(CONFIG_SCHED_PROTO) && !defined(CONFIG_SCHED_GRRR) && !defined(CONFIG_SCHED_MULTIQ) && !defined(CONFIG_SCHED_CLUTCH)
 583 #error Enable at least one scheduler algorithm in osfmk/conf/MASTER.XXX
 584 #endif
 585
 586
 587 #if CONFIG_SCHED_CLUTCH
 588 extern const struct sched_dispatch_table sched_clutch_dispatch;
 589 #define SCHED(f) (sched_clutch_dispatch.f)
 590 #else /* CONFIG_SCHED_CLUTCH */
 591 extern const struct sched_dispatch_table sched_dualq_dispatch;
 592 #define SCHED(f) (sched_dualq_dispatch.f)
 593 #endif /* CONFIG_SCHED_CLUTCH */
 594
 595
 596 struct sched_dispatch_table {
 597         const char *sched_name;
 598         void    (*init)(void);                          /* Init global state */
 599         void    (*timebase_init)(void);         /* Timebase-dependent initialization */
 600         void    (*processor_init)(processor_t processor);       /* Per-processor scheduler init */
 601         void    (*pset_init)(processor_set_t pset);     /* Per-processor set scheduler init */
 602
 603         void    (*maintenance_continuation)(void);      /* Function called regularly */
 604
 605         /*
 606          * Choose a thread of greater or equal priority from the per-processor
 607          * runqueue for timeshare/fixed threads
 608          */
 609         thread_t        (*choose_thread)(
 610                 processor_t           processor,
 611                 int                           priority,
 612                 ast_t reason);
 613
 614         /* True if scheduler supports stealing threads for this pset */
 615         bool    (*steal_thread_enabled)(processor_set_t pset);
 616
 617         /*
 618          * Steal a thread from another processor in the pset so that it can run
 619          * immediately
 620          */
 621         thread_t        (*steal_thread)(
 622                 processor_set_t         pset);
 623
 624         /*
 625          * Compute priority for a timeshare thread based on base priority.
 626          */
 627         int (*compute_timeshare_priority)(thread_t thread);
 628
 629         /*
 630          * Pick the best processor for a thread (any kind of thread) to run on.
 631          */
 632         processor_t     (*choose_processor)(
 633                 processor_set_t                pset,
 634                 processor_t                    processor,
 635                 thread_t                       thread);
 636         /*
 637          * Enqueue a timeshare or fixed priority thread onto the per-processor
 638          * runqueue
 639          */
 640         boolean_t (*processor_enqueue)(
 641                 processor_t                    processor,
 642                 thread_t                       thread,
 643                 sched_options_t                options);
 644
 645         /* Migrate threads away in preparation for processor shutdown */
 646         void (*processor_queue_shutdown)(
 647                 processor_t                    processor);
 648
 649         /* Remove the specific thread from the per-processor runqueue */
 650         boolean_t       (*processor_queue_remove)(
 651                 processor_t             processor,
 652                 thread_t                thread);
 653
 654         /*
 655          * Does the per-processor runqueue have any timeshare or fixed priority
 656          * threads on it? Called without pset lock held, so should
 657          * not assume immutability while executing.
 658          */
 659         boolean_t       (*processor_queue_empty)(processor_t            processor);
 660
 661         /*
 662          * Would this priority trigger an urgent preemption if it's sitting
 663          * on the per-processor runqueue?
 664          */
 665         boolean_t       (*priority_is_urgent)(int priority);
 666
 667         /*
 668          * Does the per-processor runqueue contain runnable threads that
 669          * should cause the currently-running thread to be preempted?
 670          */
 671         ast_t           (*processor_csw_check)(processor_t processor);
 672
 673         /*
 674          * Does the per-processor runqueue contain a runnable thread
 675          * of > or >= priority, as a preflight for choose_thread() or other
 676          * thread selection
 677          */
 678         boolean_t       (*processor_queue_has_priority)(processor_t             processor,
 679             int                             priority,
 680             boolean_t               gte);
 681
 682         /* Quantum size for the specified non-realtime thread. */
 683         uint32_t        (*initial_quantum_size)(thread_t thread);
 684
 685         /* Scheduler mode for a new thread */
 686         sched_mode_t    (*initial_thread_sched_mode)(task_t parent_task);
 687
 688         /*
 689          * Is it safe to call update_priority, which may change a thread's
 690          * runqueue or other state. This can be used to throttle changes
 691          * to dynamic priority.
 692          */
 693         boolean_t       (*can_update_priority)(thread_t thread);
 694
 695         /*
 696          * Update both scheduled priority and other persistent state.
 697          * Side effects may including migration to another processor's runqueue.
 698          */
 699         void            (*update_priority)(thread_t thread);
 700
 701         /* Lower overhead update to scheduled priority and state. */
 702         void            (*lightweight_update_priority)(thread_t thread);
 703
 704         /* Callback for non-realtime threads when the quantum timer fires */
 705         void            (*quantum_expire)(thread_t thread);
 706
 707         /*
 708          * Runnable threads on per-processor runqueue. Should only
 709          * be used for relative comparisons of load between processors.
 710          */
 711         int                     (*processor_runq_count)(processor_t     processor);
 712
 713         /* Aggregate runcount statistics for per-processor runqueue */
 714         uint64_t    (*processor_runq_stats_count_sum)(processor_t   processor);
 715
 716         boolean_t       (*processor_bound_count)(processor_t processor);
 717
 718         void            (*thread_update_scan)(sched_update_scan_context_t scan_context);
 719
 720         /* Supports more than one pset */
 721         boolean_t   multiple_psets_enabled;
 722         /* Supports scheduler groups */
 723         boolean_t   sched_groups_enabled;
 724
 725         /* Supports avoid-processor */
 726         boolean_t   avoid_processor_enabled;
 727
 728         /* Returns true if this processor should avoid running this thread. */
 729         bool    (*thread_avoid_processor)(processor_t processor, thread_t thread);
 730
 731         /*
 732          * Invoked when a processor is about to choose the idle thread
 733          * Used to send IPIs to a processor which would be preferred to be idle instead.
 734          * Called with pset lock held, returns pset lock unlocked.
 735          */
 736         void    (*processor_balance)(processor_t processor, processor_set_t pset);
 737         rt_queue_t      (*rt_runq)(processor_set_t pset);
 738         void    (*rt_init)(processor_set_t pset);
 739         void    (*rt_queue_shutdown)(processor_t processor);
 740         void    (*rt_runq_scan)(sched_update_scan_context_t scan_context);
 741         int64_t (*rt_runq_count_sum)(void);
 742
 743         uint32_t (*qos_max_parallelism)(int qos, uint64_t options);
 744         void    (*check_spill)(processor_set_t pset, thread_t thread);
 745         sched_ipi_type_t (*ipi_policy)(processor_t dst, thread_t thread, boolean_t dst_idle, sched_ipi_event_t event);
 746         bool    (*thread_should_yield)(processor_t processor, thread_t thread);
 747
 748         /* Routine to update run counts */
 749         uint32_t (*run_count_incr)(thread_t thread);
 750         uint32_t (*run_count_decr)(thread_t thread);
 751
 752         /* Routine to update scheduling bucket for a thread */
 753         void (*update_thread_bucket)(thread_t thread);
 754
 755         /* Routine to inform the scheduler when a new pset becomes schedulable */
 756         void (*pset_made_schedulable)(processor_t processor, processor_set_t pset, boolean_t drop_lock);
 757 };
 758
 759 #if defined(CONFIG_SCHED_TRADITIONAL)
 760 extern const struct sched_dispatch_table sched_traditional_dispatch;
 761 extern const struct sched_dispatch_table sched_traditional_with_pset_runqueue_dispatch;
 762 #endif
 763
 764 #if defined(CONFIG_SCHED_MULTIQ)
 765 extern const struct sched_dispatch_table sched_multiq_dispatch;
 766 extern const struct sched_dispatch_table sched_dualq_dispatch;
 767 #endif
 768
 769 #if defined(CONFIG_SCHED_PROTO)
 770 extern const struct sched_dispatch_table sched_proto_dispatch;
 771 #endif
 772
 773 #if defined(CONFIG_SCHED_GRRR)
 774 extern const struct sched_dispatch_table sched_grrr_dispatch;
 775 #endif
 776
 777 #if defined(CONFIG_SCHED_CLUTCH)
 778 extern const struct sched_dispatch_table sched_clutch_dispatch;
 779 #endif
 780
 781 #endif  /* MACH_KERNEL_PRIVATE */
 782
 783 __END_DECLS
 784
 785 #endif  /* _KERN_SCHED_PRIM_H_ */