1 /* 2 * Copyright (c) 2000-2012 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 /* 29 * @OSF_COPYRIGHT@ 30 */ 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 [email protected] 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 <sys/cdefs.h> 70 #include <mach/boolean.h> 71 #include <mach/machine/vm_types.h> 72 #include <mach/kern_return.h> 73 #include <kern/clock.h> 74 #include <kern/kern_types.h> 75 #include <kern/percpu.h> 76 #include <kern/thread.h> 77 #include <kern/block_hint.h> 78 79 extern int thread_get_current_cpuid(void); 80 81 #ifdef MACH_KERNEL_PRIVATE 82 83 #include <kern/sched_urgency.h> 84 #include <kern/thread_group.h> 85 #include <kern/waitq.h> 86 87 /* Initialization */ 88 extern void sched_init(void); 89 90 extern void sched_startup(void); 91 92 extern void sched_timebase_init(void); 93 94 extern void pset_rt_init(processor_set_t pset); 95 96 extern void sched_rtlocal_init(processor_set_t pset); 97 98 extern rt_queue_t sched_rtlocal_runq(processor_set_t pset); 99 100 extern void sched_rtlocal_queue_shutdown(processor_t processor); 101 102 extern int64_t sched_rtlocal_runq_count_sum(void); 103 104 extern thread_t sched_rtlocal_steal_thread(processor_set_t stealing_pset, uint64_t earliest_deadline); 105 106 extern thread_t sched_rt_choose_thread(processor_set_t pset); 107 108 extern void sched_check_spill(processor_set_t pset, thread_t thread); 109 110 extern bool sched_thread_should_yield(processor_t processor, thread_t thread); 111 112 extern bool sched_steal_thread_DISABLED(processor_set_t pset); 113 extern bool sched_steal_thread_enabled(processor_set_t pset); 114 115 /* Force a preemption point for a thread and wait for it to stop running */ 116 extern boolean_t thread_stop( 117 thread_t thread, 118 boolean_t until_not_runnable); 119 120 /* Release a previous stop request */ 121 extern void thread_unstop( 122 thread_t thread); 123 124 /* Wait for a thread to stop running */ 125 extern void thread_wait( 126 thread_t thread, 127 boolean_t until_not_runnable); 128 129 /* Unblock thread on wake up */ 130 extern boolean_t thread_unblock( 131 thread_t thread, 132 wait_result_t wresult); 133 134 /* Unblock and dispatch thread */ 135 extern void thread_go( 136 thread_t thread, 137 wait_result_t wresult, 138 bool try_handoff); 139 140 /* Check if direct handoff is allowed */ 141 extern boolean_t 142 thread_allowed_for_handoff( 143 thread_t thread); 144 145 /* Handle threads at context switch */ 146 extern void thread_dispatch( 147 thread_t old_thread, 148 thread_t new_thread); 149 150 /* Switch directly to a particular thread */ 151 extern int thread_run( 152 thread_t self, 153 thread_continue_t continuation, 154 void *parameter, 155 thread_t new_thread); 156 157 /* Resume thread with new stack */ 158 extern __dead2 void thread_continue(thread_t old_thread); 159 160 /* Invoke continuation */ 161 extern __dead2 void call_continuation( 162 thread_continue_t continuation, 163 void *parameter, 164 wait_result_t wresult, 165 boolean_t enable_interrupts); 166 167 /* 168 * Flags that can be passed to set_sched_pri 169 * to skip side effects 170 */ 171 __options_decl(set_sched_pri_options_t, uint32_t, { 172 SETPRI_DEFAULT = 0x0, 173 SETPRI_LAZY = 0x1, /* Avoid setting AST flags or sending IPIs */ 174 }); 175 176 /* Set the current scheduled priority */ 177 extern void set_sched_pri( 178 thread_t thread, 179 int16_t priority, 180 set_sched_pri_options_t options); 181 182 /* Set base priority of the specified thread */ 183 extern void sched_set_thread_base_priority( 184 thread_t thread, 185 int priority); 186 187 /* Set absolute base priority of the specified thread */ 188 extern void sched_set_kernel_thread_priority( 189 thread_t thread, 190 int priority); 191 192 193 /* Set the thread's true scheduling mode */ 194 extern void sched_set_thread_mode(thread_t thread, 195 sched_mode_t mode); 196 197 /* 198 * Set the thread's scheduling mode taking into account that the thread may have 199 * been demoted. 200 * */ 201 extern void sched_set_thread_mode_user(thread_t thread, 202 sched_mode_t mode); 203 204 /* 205 * Get the thread's scheduling mode taking into account that the thread may have 206 * been demoted. 207 * */ 208 extern sched_mode_t sched_get_thread_mode_user(thread_t thread); 209 210 211 /* Demote the true scheduler mode */ 212 extern void sched_thread_mode_demote(thread_t thread, 213 uint32_t reason); 214 /* Un-demote the true scheduler mode */ 215 extern void sched_thread_mode_undemote(thread_t thread, 216 uint32_t reason); 217 /* Check for a specific demotion */ 218 extern bool sched_thread_mode_has_demotion(thread_t thread, 219 uint32_t reason); 220 221 extern void sched_thread_promote_reason(thread_t thread, uint32_t reason, uintptr_t trace_obj); 222 extern void sched_thread_unpromote_reason(thread_t thread, uint32_t reason, uintptr_t trace_obj); 223 224 /* Re-evaluate base priority of thread (thread locked) */ 225 void thread_recompute_priority(thread_t thread); 226 227 /* Re-evaluate scheduled priority of thread (thread locked) */ 228 extern void thread_recompute_sched_pri( 229 thread_t thread, 230 set_sched_pri_options_t options); 231 232 /* Periodic scheduler activity */ 233 extern void sched_init_thread(void); 234 235 /* Perform sched_tick housekeeping activities */ 236 extern boolean_t can_update_priority( 237 thread_t thread); 238 239 extern void update_priority( 240 thread_t thread); 241 242 extern void lightweight_update_priority( 243 thread_t thread); 244 245 extern void sched_default_quantum_expire(thread_t thread); 246 247 /* Idle processor thread continuation */ 248 extern void idle_thread( 249 void* parameter, 250 wait_result_t result); 251 252 extern kern_return_t idle_thread_create( 253 processor_t processor); 254 255 /* Continuation return from syscall */ 256 extern void thread_syscall_return( 257 kern_return_t ret); 258 259 /* Context switch */ 260 extern wait_result_t thread_block_reason( 261 thread_continue_t continuation, 262 void *parameter, 263 ast_t reason); 264 265 __options_decl(sched_options_t, uint32_t, { 266 SCHED_NONE = 0x0, 267 SCHED_TAILQ = 0x1, 268 SCHED_HEADQ = 0x2, 269 SCHED_PREEMPT = 0x4, 270 SCHED_REBALANCE = 0x8, 271 }); 272 273 /* Reschedule thread for execution */ 274 extern void thread_setrun( 275 thread_t thread, 276 sched_options_t options); 277 278 extern processor_set_t task_choose_pset( 279 task_t task); 280 281 /* Bind the current thread to a particular processor */ 282 extern processor_t thread_bind( 283 processor_t processor); 284 285 extern bool pset_has_stealable_threads( 286 processor_set_t pset); 287 288 extern bool pset_has_stealable_rt_threads( 289 processor_set_t pset); 290 291 extern processor_set_t choose_starting_pset( 292 pset_node_t node, 293 thread_t thread, 294 processor_t *processor_hint); 295 296 extern int pset_available_cpu_count( 297 processor_set_t pset); 298 299 extern bool pset_is_recommended( 300 processor_set_t pset); 301 302 extern pset_node_t sched_choose_node( 303 thread_t thread); 304 305 /* Choose the best processor to run a thread */ 306 extern processor_t choose_processor( 307 processor_set_t pset, 308 processor_t processor, 309 thread_t thread); 310 311 extern void sched_SMT_balance( 312 processor_t processor, 313 processor_set_t pset); 314 315 extern void thread_quantum_init( 316 thread_t thread, 317 uint64_t now); 318 319 320 extern void run_queue_init( 321 run_queue_t runq); 322 323 extern thread_t run_queue_dequeue( 324 run_queue_t runq, 325 sched_options_t options); 326 327 extern boolean_t run_queue_enqueue( 328 run_queue_t runq, 329 thread_t thread, 330 sched_options_t options); 331 332 extern void run_queue_remove( 333 run_queue_t runq, 334 thread_t thread); 335 336 extern thread_t run_queue_peek( 337 run_queue_t runq); 338 339 struct sched_update_scan_context { 340 uint64_t earliest_bg_make_runnable_time; 341 uint64_t earliest_normal_make_runnable_time; 342 uint64_t earliest_rt_make_runnable_time; 343 uint64_t sched_tick_last_abstime; 344 }; 345 typedef struct sched_update_scan_context *sched_update_scan_context_t; 346 347 extern void sched_rtlocal_runq_scan(sched_update_scan_context_t scan_context); 348 349 extern void sched_pset_made_schedulable( 350 processor_t processor, 351 processor_set_t pset, 352 boolean_t drop_lock); 353 354 extern void sched_cpu_init_completed(void); 355 356 /* 357 * Enum to define various events which need IPIs. The IPI policy 358 * engine decides what kind of IPI to use based on destination 359 * processor state, thread and one of the following scheduling events. 360 */ 361 typedef enum { 362 SCHED_IPI_EVENT_BOUND_THR = 0x1, 363 SCHED_IPI_EVENT_PREEMPT = 0x2, 364 SCHED_IPI_EVENT_SMT_REBAL = 0x3, 365 SCHED_IPI_EVENT_SPILL = 0x4, 366 SCHED_IPI_EVENT_REBALANCE = 0x5, 367 SCHED_IPI_EVENT_RT_PREEMPT = 0x6, 368 } sched_ipi_event_t; 369 370 371 /* Enum to define various IPI types used by the scheduler */ 372 typedef enum { 373 SCHED_IPI_NONE = 0x0, 374 SCHED_IPI_IMMEDIATE = 0x1, 375 SCHED_IPI_IDLE = 0x2, 376 SCHED_IPI_DEFERRED = 0x3, 377 } sched_ipi_type_t; 378 379 /* The IPI policy engine behaves in the following manner: 380 * - All scheduler events which need an IPI invoke sched_ipi_action() with 381 * the appropriate destination processor, thread and event. 382 * - sched_ipi_action() performs basic checks, invokes the scheduler specific 383 * ipi_policy routine and sets pending_AST bits based on the result. 384 * - Once the pset lock is dropped, the scheduler invokes sched_ipi_perform() 385 * routine which actually sends the appropriate IPI to the destination core. 386 */ 387 extern sched_ipi_type_t sched_ipi_action(processor_t dst, thread_t thread, sched_ipi_event_t event); 388 extern void sched_ipi_perform(processor_t dst, sched_ipi_type_t ipi); 389 390 /* sched_ipi_policy() is the global default IPI policy for all schedulers */ 391 extern sched_ipi_type_t sched_ipi_policy(processor_t dst, thread_t thread, 392 boolean_t dst_idle, sched_ipi_event_t event); 393 394 /* sched_ipi_deferred_policy() is the global default deferred IPI policy for all schedulers */ 395 extern sched_ipi_type_t sched_ipi_deferred_policy(processor_set_t pset, 396 processor_t dst, thread_t thread, sched_ipi_event_t event); 397 398 #if defined(CONFIG_SCHED_TIMESHARE_CORE) 399 400 extern boolean_t thread_update_add_thread(thread_t thread); 401 extern void thread_update_process_threads(void); 402 extern boolean_t runq_scan(run_queue_t runq, sched_update_scan_context_t scan_context); 403 404 #if CONFIG_SCHED_CLUTCH 405 extern boolean_t sched_clutch_timeshare_scan(queue_t thread_queue, uint16_t count, sched_update_scan_context_t scan_context); 406 #endif /* CONFIG_SCHED_CLUTCH */ 407 408 extern void sched_timeshare_init(void); 409 extern void sched_timeshare_timebase_init(void); 410 extern void sched_timeshare_maintenance_continue(void); 411 412 extern boolean_t priority_is_urgent(int priority); 413 extern uint32_t sched_timeshare_initial_quantum_size(thread_t thread); 414 415 extern int sched_compute_timeshare_priority(thread_t thread); 416 417 #endif /* CONFIG_SCHED_TIMESHARE_CORE */ 418 419 /* Remove thread from its run queue */ 420 extern boolean_t thread_run_queue_remove(thread_t thread); 421 thread_t thread_run_queue_remove_for_handoff(thread_t thread); 422 423 /* Put a thread back in the run queue after being yanked */ 424 extern void thread_run_queue_reinsert(thread_t thread, sched_options_t options); 425 426 extern void thread_timer_expire( 427 void *thread, 428 void *p1); 429 430 extern bool thread_is_eager_preempt(thread_t thread); 431 432 extern boolean_t sched_generic_direct_dispatch_to_idle_processors; 433 434 /* Set the maximum interrupt level for the thread */ 435 __private_extern__ wait_interrupt_t thread_interrupt_level( 436 wait_interrupt_t interruptible); 437 438 __private_extern__ wait_result_t thread_mark_wait_locked( 439 thread_t thread, 440 wait_interrupt_t interruptible); 441 442 /* Wake up locked thread directly, passing result */ 443 __private_extern__ kern_return_t clear_wait_internal( 444 thread_t thread, 445 wait_result_t result); 446 447 struct sched_statistics { 448 uint32_t csw_count; 449 uint32_t preempt_count; 450 uint32_t preempted_rt_count; 451 uint32_t preempted_by_rt_count; 452 uint32_t rt_sched_count; 453 uint32_t interrupt_count; 454 uint32_t ipi_count; 455 uint32_t timer_pop_count; 456 uint32_t idle_transitions; 457 uint32_t quantum_timer_expirations; 458 }; 459 PERCPU_DECL(struct sched_statistics, sched_stats); 460 extern bool sched_stats_active; 461 462 extern void sched_stats_handle_csw( 463 processor_t processor, 464 int reasons, 465 int selfpri, 466 int otherpri); 467 468 extern void sched_stats_handle_runq_change( 469 struct runq_stats *stats, 470 int old_count); 471 472 #define SCHED_STATS_INC(field) \ 473 MACRO_BEGIN \ 474 if (__improbable(sched_stats_active)) { \ 475 PERCPU_GET(sched_stats)->field++; \ 476 } \ 477 MACRO_END 478 479 #if DEBUG 480 481 #define SCHED_STATS_CSW(processor, reasons, selfpri, otherpri) \ 482 MACRO_BEGIN \ 483 if (__improbable(sched_stats_active)) { \ 484 sched_stats_handle_csw((processor), \ 485 (reasons), (selfpri), (otherpri)); \ 486 } \ 487 MACRO_END 488 489 490 #define SCHED_STATS_RUNQ_CHANGE(stats, old_count) \ 491 MACRO_BEGIN \ 492 if (__improbable(sched_stats_active)) { \ 493 sched_stats_handle_runq_change((stats), (old_count)); \ 494 } \ 495 MACRO_END 496 497 #else /* DEBUG */ 498 499 #define SCHED_STATS_CSW(processor, reasons, selfpri, otherpri) do { }while(0) 500 #define SCHED_STATS_RUNQ_CHANGE(stats, old_count) do { }while(0) 501 502 #endif /* DEBUG */ 503 504 extern uint32_t sched_debug_flags; 505 #define SCHED_DEBUG_FLAG_PLATFORM_TRACEPOINTS 0x00000001 506 #define SCHED_DEBUG_FLAG_CHOOSE_PROCESSOR_TRACEPOINTS 0x00000002 507 508 #define SCHED_DEBUG_PLATFORM_KERNEL_DEBUG_CONSTANT(...) \ 509 MACRO_BEGIN \ 510 if (__improbable(sched_debug_flags & \ 511 SCHED_DEBUG_FLAG_PLATFORM_TRACEPOINTS)) { \ 512 KERNEL_DEBUG_CONSTANT(__VA_ARGS__); \ 513 } \ 514 MACRO_END 515 516 #define SCHED_DEBUG_CHOOSE_PROCESSOR_KERNEL_DEBUG_CONSTANT_IST(...) \ 517 MACRO_BEGIN \ 518 if (__improbable(sched_debug_flags & \ 519 SCHED_DEBUG_FLAG_CHOOSE_PROCESSOR_TRACEPOINTS)) { \ 520 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, __VA_ARGS__); \ 521 } \ 522 MACRO_END 523 524 /* Tells if there are "active" RT threads in the system (provided by CPU PM) */ 525 extern void active_rt_threads( 526 boolean_t active); 527 528 /* Returns the perfcontrol attribute for the thread */ 529 extern perfcontrol_class_t thread_get_perfcontrol_class( 530 thread_t thread); 531 532 /* Generic routine for Non-AMP schedulers to calculate parallelism */ 533 extern uint32_t sched_qos_max_parallelism(int qos, uint64_t options); 534 535 extern void check_monotonic_time(uint64_t ctime); 536 537 #endif /* MACH_KERNEL_PRIVATE */ 538 539 __BEGIN_DECLS 540 541 #ifdef XNU_KERNEL_PRIVATE 542 543 extern void thread_bind_cluster_type(thread_t, char cluster_type, bool soft_bind); 544 545 __options_decl(thread_bind_option_t, uint64_t, { 546 /* Unbind a previously cluster bound thread */ 547 THREAD_UNBIND = 0x1, 548 /* 549 * Soft bind the thread to the cluster; soft binding means the thread will be 550 * moved to an available cluster if the bound cluster is de-recommended/offline. 551 */ 552 THREAD_BIND_SOFT = 0x2, 553 /* 554 * Bind thread to the cluster only if it is eligible to run on that cluster. If 555 * the thread is not eligible to run on the cluster, thread_bind_cluster_id() 556 * returns KERN_INVALID_POLICY. 557 */ 558 THREAD_BIND_ELIGIBLE_ONLY = 0x4, 559 }); 560 extern kern_return_t thread_bind_cluster_id(thread_t thread, uint32_t cluster_id, thread_bind_option_t options); 561 562 extern int sched_get_rt_n_backup_processors(void); 563 extern void sched_set_rt_n_backup_processors(int n); 564 565 extern int sched_get_rt_deadline_epsilon(void); 566 extern void sched_set_rt_deadline_epsilon(int new_epsilon_us); 567 568 /* Toggles a global override to turn off CPU Throttling */ 569 extern void sys_override_cpu_throttle(boolean_t enable_override); 570 571 extern int sched_get_powered_cores(void); 572 extern void sched_set_powered_cores(int n); 573 574 /* 575 ****************** Only exported until BSD stops using ******************** 576 */ 577 578 extern void thread_vm_bind_group_add(void); 579 580 /* Wake up thread directly, passing result */ 581 extern kern_return_t clear_wait( 582 thread_t thread, 583 wait_result_t result); 584 585 /* Start thread running */ 586 extern void thread_bootstrap_return(void) __attribute__((noreturn)); 587 588 /* Return from exception (BSD-visible interface) */ 589 extern void thread_exception_return(void) __dead2; 590 591 #define SCHED_STRING_MAX_LENGTH (48) 592 /* String declaring the name of the current scheduler */ 593 extern char sched_string[SCHED_STRING_MAX_LENGTH]; 594 595 __options_decl(thread_handoff_option_t, uint32_t, { 596 THREAD_HANDOFF_NONE = 0, 597 THREAD_HANDOFF_SETRUN_NEEDED = 0x1, 598 }); 599 600 /* Remove thread from its run queue */ 601 thread_t thread_prepare_for_handoff(thread_t thread, thread_handoff_option_t option); 602 603 /* Attempt to context switch to a specific runnable thread */ 604 extern wait_result_t thread_handoff_deallocate(thread_t thread, thread_handoff_option_t option); 605 606 __attribute__((nonnull(2))) 607 extern void thread_handoff_parameter(thread_t thread, 608 thread_continue_t continuation, void *parameter, thread_handoff_option_t) __dead2; 609 610 extern struct waitq *assert_wait_queue(event_t event); 611 612 extern kern_return_t thread_wakeup_one_with_pri(event_t event, int priority); 613 614 extern thread_t thread_wakeup_identify(event_t event, int priority); 615 616 /* 617 * sched_cond_t: 618 * 619 * A atomic condition variable used to synchronize wake/block operations on threads. 620 * Bits defined below are reserved for use by sched_prim. Remaining 621 * bits may be used by caller for additional synchronization semantics. 622 */ 623 __options_decl(sched_cond_t, uint32_t, { 624 SCHED_COND_INIT = 0x0000, /* initialize all bits to zero (inactive and not awoken) */ 625 SCHED_COND_ACTIVE = 0x0001, /* target thread is active */ 626 SCHED_COND_WAKEUP = 0x0002 /* wakeup has been issued for target thread */ 627 }); 628 typedef _Atomic sched_cond_t sched_cond_atomic_t; 629 630 /* 631 * sched_cond_init: 632 * 633 * Initialize an atomic condition variable. Note that this does not occur atomically and should be 634 * performed during thread initialization, before the condition is observable by other threads. 635 */ 636 extern void sched_cond_init( 637 sched_cond_atomic_t *cond); 638 639 /* 640 * sched_cond_signal: 641 * 642 * Wakeup the specified thread if it is waiting on this event and it has not already been issued a wakeup. 643 * 644 * parameters: 645 * thread thread to awaken 646 * cond atomic condition variable 647 */ 648 extern kern_return_t sched_cond_signal( 649 sched_cond_atomic_t *cond, 650 thread_t thread); 651 652 /* 653 * sched_cond_wait_parameter: 654 * 655 * Assert wait and block on cond if no wakeup has been issued. 656 * If a wakeup has been issued on cond since the last `sched_cond_ack`, clear_wait and 657 * return `THREAD_AWAKENED`. 658 * 659 * `sched_cond_wait_parameter` must be paired with `sched_cond_ack`. 660 * 661 * NOTE: `continuation` will only be jumped to if a wakeup has not been issued 662 * 663 * parameters: 664 * cond atomic condition variable to synchronize on 665 * interruptible interruptible value to pass to assert_wait 666 * continuation continuation if block succeeds 667 * parameter 668 */ 669 extern wait_result_t sched_cond_wait_parameter( 670 sched_cond_atomic_t *cond, 671 wait_interrupt_t interruptible, 672 thread_continue_t continuation, 673 void *parameter); 674 675 /* 676 * sched_cond_wait: 677 * 678 * Assert wait and block on cond if no wakeup has been issued. 679 * If a wakeup has been issued on cond since the last `sched_cond_ack`, clear_wait and 680 * return `THREAD_AWAKENED`. 681 * 682 * `sched_cond_wait` must be paired with `sched_cond_ack`. 683 * 684 * NOTE: `continuation` will only be jumped to if a wakeup has not been issued 685 * 686 * parameters: 687 * cond atomic condition variable to synchronize on 688 * interruptible interruptible value to pass to assert_wait 689 * continuation continuation if block succeeds 690 */ 691 extern wait_result_t sched_cond_wait( 692 sched_cond_atomic_t *cond, 693 wait_interrupt_t interruptible, 694 thread_continue_t continuation); 695 696 /* 697 * sched_cond_ack: 698 * 699 * Acknowledge an issued wakeup by clearing WAKEUP and setting ACTIVE (via XOR). 700 * It is the callers responsibility to ensure that the ACTIVE bit is always low prior to calling 701 * (i.e. by calling `sched_cond_wait` prior to any rerun or block). 702 * Synchronization schemes that allow for WAKEUP bit to be reset prior to wakeup 703 * (e.g. a cancellation mechanism) should check that WAKEUP was indeed cleared. 704 * 705 * e.g. 706 * ``` 707 * if (sched_cond_ack(&my_state) & SCHED_THREAD_WAKEUP) { 708 * // WAKEUP bit was no longer set by the time this thread woke up 709 * do_cancellation_policy(); 710 * } 711 * ``` 712 * 713 * parameters: 714 * cond: atomic condition variable 715 */ 716 extern sched_cond_t sched_cond_ack( 717 sched_cond_atomic_t *cond); 718 719 #endif /* XNU_KERNEL_PRIVATE */ 720 721 #ifdef KERNEL_PRIVATE 722 /* Set pending block hint for a particular object before we go into a wait state */ 723 extern void thread_set_pending_block_hint( 724 thread_t thread, 725 block_hint_t block_hint); 726 727 #define QOS_PARALLELISM_COUNT_LOGICAL 0x1 728 #define QOS_PARALLELISM_REALTIME 0x2 729 #define QOS_PARALLELISM_CLUSTER_SHARED_RESOURCE 0x4 730 731 extern uint32_t qos_max_parallelism(int qos, uint64_t options); 732 #endif /* KERNEL_PRIVATE */ 733 734 #if XNU_KERNEL_PRIVATE 735 extern void thread_yield_with_continuation( 736 thread_continue_t continuation, 737 void *parameter) __dead2; 738 #endif 739 740 /* Context switch */ 741 extern wait_result_t thread_block( 742 thread_continue_t continuation); 743 744 extern wait_result_t thread_block_parameter( 745 thread_continue_t continuation, 746 void *parameter); 747 748 /* Declare thread will wait on a particular event */ 749 extern wait_result_t assert_wait( 750 event_t event, 751 wait_interrupt_t interruptible); 752 753 /* Assert that the thread intends to wait with a timeout */ 754 extern wait_result_t assert_wait_timeout( 755 event_t event, 756 wait_interrupt_t interruptible, 757 uint32_t interval, 758 uint32_t scale_factor); 759 760 /* Assert that the thread intends to wait with an urgency, timeout and leeway */ 761 extern wait_result_t assert_wait_timeout_with_leeway( 762 event_t event, 763 wait_interrupt_t interruptible, 764 wait_timeout_urgency_t urgency, 765 uint32_t interval, 766 uint32_t leeway, 767 uint32_t scale_factor); 768 769 extern wait_result_t assert_wait_deadline( 770 event_t event, 771 wait_interrupt_t interruptible, 772 uint64_t deadline); 773 774 /* Assert that the thread intends to wait with an urgency, deadline, and leeway */ 775 extern wait_result_t assert_wait_deadline_with_leeway( 776 event_t event, 777 wait_interrupt_t interruptible, 778 wait_timeout_urgency_t urgency, 779 uint64_t deadline, 780 uint64_t leeway); 781 782 783 /* Wake up thread (or threads) waiting on a particular event */ 784 extern kern_return_t thread_wakeup_prim( 785 event_t event, 786 boolean_t one_thread, 787 wait_result_t result); 788 789 #define thread_wakeup(x) \ 790 thread_wakeup_prim((x), FALSE, THREAD_AWAKENED) 791 #define thread_wakeup_with_result(x, z) \ 792 thread_wakeup_prim((x), FALSE, (z)) 793 #define thread_wakeup_one(x) \ 794 thread_wakeup_prim((x), TRUE, THREAD_AWAKENED) 795 796 /* Wakeup the specified thread if it is waiting on this event */ 797 extern kern_return_t thread_wakeup_thread(event_t event, thread_t thread); 798 799 extern boolean_t preemption_enabled(void); 800 801 #ifdef MACH_KERNEL_PRIVATE 802 803 /* 804 * Scheduler algorithm indirection. If only one algorithm is 805 * enabled at compile-time, a direction function call is used. 806 * If more than one is enabled, calls are dispatched through 807 * a function pointer table. 808 */ 809 810 #if !defined(CONFIG_SCHED_TRADITIONAL) && !defined(CONFIG_SCHED_PROTO) && !defined(CONFIG_SCHED_GRRR) && !defined(CONFIG_SCHED_MULTIQ) && !defined(CONFIG_SCHED_CLUTCH) && !defined(CONFIG_SCHED_EDGE) 811 #error Enable at least one scheduler algorithm in osfmk/conf/MASTER.XXX 812 #endif 813 814 #if __AMP__ 815 816 #if CONFIG_SCHED_EDGE 817 extern const struct sched_dispatch_table sched_edge_dispatch; 818 #define SCHED(f) (sched_edge_dispatch.f) 819 #else /* CONFIG_SCHED_EDGE */ 820 extern const struct sched_dispatch_table sched_amp_dispatch; 821 #define SCHED(f) (sched_amp_dispatch.f) 822 #endif /* CONFIG_SCHED_EDGE */ 823 824 #else /* __AMP__ */ 825 826 #if CONFIG_SCHED_CLUTCH 827 extern const struct sched_dispatch_table sched_clutch_dispatch; 828 #define SCHED(f) (sched_clutch_dispatch.f) 829 #else /* CONFIG_SCHED_CLUTCH */ 830 extern const struct sched_dispatch_table sched_dualq_dispatch; 831 #define SCHED(f) (sched_dualq_dispatch.f) 832 #endif /* CONFIG_SCHED_CLUTCH */ 833 834 #endif /* __AMP__ */ 835 836 struct sched_dispatch_table { 837 const char *sched_name; 838 void (*init)(void); /* Init global state */ 839 void (*timebase_init)(void); /* Timebase-dependent initialization */ 840 void (*processor_init)(processor_t processor); /* Per-processor scheduler init */ 841 void (*pset_init)(processor_set_t pset); /* Per-processor set scheduler init */ 842 843 void (*maintenance_continuation)(void); /* Function called regularly */ 844 845 /* 846 * Choose a thread of greater or equal priority from the per-processor 847 * runqueue for timeshare/fixed threads 848 */ 849 thread_t (*choose_thread)( 850 processor_t processor, 851 int priority, 852 ast_t reason); 853 854 /* True if scheduler supports stealing threads for this pset */ 855 bool (*steal_thread_enabled)(processor_set_t pset); 856 857 /* 858 * Steal a thread from another processor in the pset so that it can run 859 * immediately 860 */ 861 thread_t (*steal_thread)( 862 processor_set_t pset); 863 864 /* 865 * Compute priority for a timeshare thread based on base priority. 866 */ 867 int (*compute_timeshare_priority)(thread_t thread); 868 869 /* 870 * Pick the best node for a thread to run on. 871 */ 872 pset_node_t (*choose_node)( 873 thread_t thread); 874 875 /* 876 * Pick the best processor for a thread (any kind of thread) to run on. 877 */ 878 processor_t (*choose_processor)( 879 processor_set_t pset, 880 processor_t processor, 881 thread_t thread); 882 /* 883 * Enqueue a timeshare or fixed priority thread onto the per-processor 884 * runqueue 885 */ 886 boolean_t (*processor_enqueue)( 887 processor_t processor, 888 thread_t thread, 889 sched_options_t options); 890 891 /* Migrate threads away in preparation for processor shutdown */ 892 void (*processor_queue_shutdown)( 893 processor_t processor); 894 895 /* Remove the specific thread from the per-processor runqueue */ 896 boolean_t (*processor_queue_remove)( 897 processor_t processor, 898 thread_t thread); 899 900 /* 901 * Does the per-processor runqueue have any timeshare or fixed priority 902 * threads on it? Called without pset lock held, so should 903 * not assume immutability while executing. 904 */ 905 boolean_t (*processor_queue_empty)(processor_t processor); 906 907 /* 908 * Would this priority trigger an urgent preemption if it's sitting 909 * on the per-processor runqueue? 910 */ 911 boolean_t (*priority_is_urgent)(int priority); 912 913 /* 914 * Does the per-processor runqueue contain runnable threads that 915 * should cause the currently-running thread to be preempted? 916 */ 917 ast_t (*processor_csw_check)(processor_t processor); 918 919 /* 920 * Does the per-processor runqueue contain a runnable thread 921 * of > or >= priority, as a preflight for choose_thread() or other 922 * thread selection 923 */ 924 boolean_t (*processor_queue_has_priority)(processor_t processor, 925 int priority, 926 boolean_t gte); 927 928 /* Quantum size for the specified non-realtime thread. */ 929 uint32_t (*initial_quantum_size)(thread_t thread); 930 931 /* Scheduler mode for a new thread */ 932 sched_mode_t (*initial_thread_sched_mode)(task_t parent_task); 933 934 /* 935 * Is it safe to call update_priority, which may change a thread's 936 * runqueue or other state. This can be used to throttle changes 937 * to dynamic priority. 938 */ 939 boolean_t (*can_update_priority)(thread_t thread); 940 941 /* 942 * Update both scheduled priority and other persistent state. 943 * Side effects may including migration to another processor's runqueue. 944 */ 945 void (*update_priority)(thread_t thread); 946 947 /* Lower overhead update to scheduled priority and state. */ 948 void (*lightweight_update_priority)(thread_t thread); 949 950 /* Callback for non-realtime threads when the quantum timer fires */ 951 void (*quantum_expire)(thread_t thread); 952 953 /* 954 * Runnable threads on per-processor runqueue. Should only 955 * be used for relative comparisons of load between processors. 956 */ 957 int (*processor_runq_count)(processor_t processor); 958 959 /* Aggregate runcount statistics for per-processor runqueue */ 960 uint64_t (*processor_runq_stats_count_sum)(processor_t processor); 961 962 boolean_t (*processor_bound_count)(processor_t processor); 963 964 void (*thread_update_scan)(sched_update_scan_context_t scan_context); 965 966 /* Supports more than one pset */ 967 boolean_t multiple_psets_enabled; 968 /* Supports scheduler groups */ 969 boolean_t sched_groups_enabled; 970 971 /* Supports avoid-processor */ 972 boolean_t avoid_processor_enabled; 973 974 /* Returns true if this processor should avoid running this thread. */ 975 bool (*thread_avoid_processor)(processor_t processor, thread_t thread); 976 977 /* 978 * Invoked when a processor is about to choose the idle thread 979 * Used to send IPIs to a processor which would be preferred to be idle instead. 980 * Called with pset lock held, returns pset lock unlocked. 981 */ 982 void (*processor_balance)(processor_t processor, processor_set_t pset); 983 rt_queue_t (*rt_runq)(processor_set_t pset); 984 void (*rt_init)(processor_set_t pset); 985 void (*rt_queue_shutdown)(processor_t processor); 986 void (*rt_runq_scan)(sched_update_scan_context_t scan_context); 987 int64_t (*rt_runq_count_sum)(void); 988 thread_t (*rt_steal_thread)(processor_set_t pset, uint64_t earliest_deadline); 989 990 uint32_t (*qos_max_parallelism)(int qos, uint64_t options); 991 void (*check_spill)(processor_set_t pset, thread_t thread); 992 sched_ipi_type_t (*ipi_policy)(processor_t dst, thread_t thread, boolean_t dst_idle, sched_ipi_event_t event); 993 bool (*thread_should_yield)(processor_t processor, thread_t thread); 994 995 /* Routine to update run counts */ 996 uint32_t (*run_count_incr)(thread_t thread); 997 uint32_t (*run_count_decr)(thread_t thread); 998 999 /* Routine to update scheduling bucket for a thread */ 1000 void (*update_thread_bucket)(thread_t thread); 1001 1002 /* Routine to inform the scheduler when a new pset becomes schedulable */ 1003 void (*pset_made_schedulable)(processor_t processor, processor_set_t pset, boolean_t drop_lock); 1004 #if CONFIG_THREAD_GROUPS 1005 /* Routine to inform the scheduler when CLPC changes a thread group recommendation */ 1006 void (*thread_group_recommendation_change)(struct thread_group *tg, cluster_type_t new_recommendation); 1007 #endif 1008 /* Routine to inform the scheduler when all CPUs have finished initializing */ 1009 void (*cpu_init_completed)(void); 1010 /* Routine to check if a thread is eligible to execute on a specific pset */ 1011 bool (*thread_eligible_for_pset)(thread_t thread, processor_set_t pset); 1012 }; 1013 1014 #if defined(CONFIG_SCHED_TRADITIONAL) 1015 extern const struct sched_dispatch_table sched_traditional_dispatch; 1016 extern const struct sched_dispatch_table sched_traditional_with_pset_runqueue_dispatch; 1017 #endif 1018 1019 #if defined(CONFIG_SCHED_MULTIQ) 1020 extern const struct sched_dispatch_table sched_multiq_dispatch; 1021 extern const struct sched_dispatch_table sched_dualq_dispatch; 1022 #if __AMP__ 1023 extern const struct sched_dispatch_table sched_amp_dispatch; 1024 #endif 1025 #endif 1026 1027 #if defined(CONFIG_SCHED_PROTO) 1028 extern const struct sched_dispatch_table sched_proto_dispatch; 1029 #endif 1030 1031 #if defined(CONFIG_SCHED_GRRR) 1032 extern const struct sched_dispatch_table sched_grrr_dispatch; 1033 #endif 1034 1035 #if defined(CONFIG_SCHED_CLUTCH) 1036 extern const struct sched_dispatch_table sched_clutch_dispatch; 1037 #endif 1038 1039 #if defined(CONFIG_SCHED_EDGE) 1040 extern const struct sched_dispatch_table sched_edge_dispatch; 1041 #endif 1042 1043 extern void sched_set_max_unsafe_rt_quanta(int max); 1044 extern void sched_set_max_unsafe_fixed_quanta(int max); 1045 1046 #endif /* MACH_KERNEL_PRIVATE */ 1047 1048 __END_DECLS 1049 1050 #endif /* _KERN_SCHED_PRIM_H_ */ 1051