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 #if XNU_KERNEL_PRIVATE 82 83 /* 84 * The quantum length used for Fixed and RT sched modes. In general the quantum 85 * can vary - for example for background or QOS. 86 */ 87 uint64_t sched_get_quantum_us(void); 88 89 #endif /* XNU_KERNEL_PRIVATE */ 90 91 #if defined(MACH_KERNEL_PRIVATE) || SCHED_TEST_HARNESS 92 93 #include <kern/sched_urgency.h> 94 #include <kern/thread_group.h> 95 #include <kern/waitq.h> 96 97 /* Initialization */ 98 extern void sched_init(void); 99 100 extern void sched_startup(void); 101 102 extern void sched_timebase_init(void); 103 104 extern bool processor_is_fast_track_candidate_for_realtime_thread(processor_set_t pset, processor_t processor); 105 106 extern void sched_check_spill(processor_set_t pset, thread_t thread); 107 108 extern bool sched_thread_should_yield(processor_t processor, thread_t thread); 109 110 extern bool sched_steal_thread_DISABLED(processor_set_t pset); 111 extern bool sched_steal_thread_enabled(processor_set_t pset); 112 113 /* Force a preemption point for a thread and wait for it to stop running */ 114 extern boolean_t thread_stop( 115 thread_t thread, 116 boolean_t until_not_runnable); 117 118 /* Release a previous stop request */ 119 extern void thread_unstop( 120 thread_t thread); 121 122 /* Wait for a thread to stop running */ 123 extern void thread_wait( 124 thread_t thread, 125 boolean_t until_not_runnable); 126 127 /* Unblock thread on wake up */ 128 extern boolean_t thread_unblock( 129 thread_t thread, 130 wait_result_t wresult); 131 132 /* Unblock and dispatch thread */ 133 extern void thread_go( 134 thread_t thread, 135 wait_result_t wresult, 136 bool try_handoff); 137 138 /* Check if direct handoff is allowed */ 139 extern boolean_t 140 thread_allowed_for_handoff( 141 thread_t thread); 142 143 /* Handle threads at context switch */ 144 extern void thread_dispatch( 145 thread_t old_thread, 146 thread_t new_thread); 147 148 /* Switch directly to a particular thread */ 149 extern int thread_run( 150 thread_t self, 151 thread_continue_t continuation, 152 void *parameter, 153 thread_t new_thread); 154 155 /* Resume thread with new stack */ 156 extern __dead2 void thread_continue(thread_t old_thread); 157 158 /* Invoke continuation */ 159 extern __dead2 void call_continuation( 160 thread_continue_t continuation, 161 void *parameter, 162 wait_result_t wresult, 163 boolean_t enable_interrupts); 164 165 /* 166 * Flags that can be passed to set_sched_pri 167 * to skip side effects 168 */ 169 __options_decl(set_sched_pri_options_t, uint32_t, { 170 SETPRI_DEFAULT = 0x0, 171 SETPRI_LAZY = 0x1, /* Avoid setting AST flags or sending IPIs */ 172 }); 173 174 /* Set the current scheduled priority */ 175 extern void set_sched_pri( 176 thread_t thread, 177 int16_t priority, 178 set_sched_pri_options_t options); 179 180 /* Set base priority of the specified thread */ 181 extern void sched_set_thread_base_priority( 182 thread_t thread, 183 int priority); 184 185 /* Set absolute base priority of the specified thread */ 186 extern void sched_set_kernel_thread_priority( 187 thread_t thread, 188 int priority); 189 190 191 /* Set the thread's true scheduling mode */ 192 extern void sched_set_thread_mode(thread_t thread, 193 sched_mode_t mode); 194 195 /* 196 * Set the thread's scheduling mode taking into account that the thread may have 197 * been demoted. 198 * */ 199 extern void sched_set_thread_mode_user(thread_t thread, 200 sched_mode_t mode); 201 202 /* 203 * Get the thread's scheduling mode taking into account that the thread may have 204 * been demoted. 205 * */ 206 extern sched_mode_t sched_get_thread_mode_user(thread_t thread); 207 208 209 /* Demote the true scheduler mode */ 210 extern void sched_thread_mode_demote(thread_t thread, 211 uint32_t reason); 212 /* Un-demote the true scheduler mode */ 213 extern void sched_thread_mode_undemote(thread_t thread, 214 uint32_t reason); 215 /* Check for a specific demotion */ 216 extern bool sched_thread_mode_has_demotion(thread_t thread, 217 uint32_t reason); 218 219 extern void sched_thread_promote_reason(thread_t thread, uint32_t reason, uintptr_t trace_obj); 220 extern void sched_thread_unpromote_reason(thread_t thread, uint32_t reason, uintptr_t trace_obj); 221 222 /* Re-evaluate base priority of thread (thread locked) */ 223 void thread_recompute_priority(thread_t thread); 224 225 /* Re-evaluate scheduled priority of thread (thread locked) */ 226 extern void thread_recompute_sched_pri( 227 thread_t thread, 228 set_sched_pri_options_t options); 229 230 /* Periodic scheduler activity */ 231 extern void sched_init_thread(void); 232 233 /* Perform sched_tick housekeeping activities */ 234 extern boolean_t can_update_priority( 235 thread_t thread); 236 237 extern void update_priority( 238 thread_t thread); 239 240 extern void lightweight_update_priority( 241 thread_t thread); 242 243 extern void sched_default_quantum_expire(thread_t thread); 244 245 /* Idle processor thread continuation */ 246 extern void idle_thread( 247 void* parameter, 248 wait_result_t result); 249 250 extern void idle_thread_create( 251 processor_t processor, 252 thread_continue_t continuation); 253 254 /* Continuation return from syscall */ 255 extern void thread_syscall_return( 256 kern_return_t ret); 257 258 /* Context switch */ 259 extern wait_result_t thread_block_reason( 260 thread_continue_t continuation, 261 void *parameter, 262 ast_t reason); 263 264 __options_decl(sched_options_t, uint32_t, { 265 SCHED_NONE = 0x0, 266 SCHED_TAILQ = 0x1, 267 SCHED_HEADQ = 0x2, 268 SCHED_PREEMPT = 0x4, 269 SCHED_REBALANCE = 0x8, 270 SCHED_STIR_POT = 0x10, 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 void thread_bind_during_wakeup( 286 thread_t thread, 287 processor_t processor); 288 289 extern void thread_unbind_after_queue_shutdown( 290 thread_t thread, 291 processor_t processor); 292 293 extern bool pset_has_stealable_threads( 294 processor_set_t pset); 295 296 extern processor_set_t choose_starting_pset( 297 pset_node_t node, 298 thread_t thread, 299 processor_t *processor_hint); 300 301 extern int pset_available_cpu_count( 302 processor_set_t pset); 303 304 extern bool pset_is_recommended( 305 processor_set_t pset); 306 307 extern bool pset_type_is_recommended( 308 processor_set_t pset); 309 310 extern pset_node_t sched_choose_node( 311 thread_t thread); 312 313 #if CONFIG_SCHED_SMT 314 extern processor_t choose_processor_smt( 315 processor_set_t pset, 316 processor_t processor, 317 thread_t thread, 318 sched_options_t *options); 319 #else /* !CONFIG_SCHED_SMT */ 320 /* Choose the best processor to run a thread */ 321 extern processor_t choose_processor( 322 processor_set_t pset, 323 processor_t processor, 324 thread_t thread, 325 sched_options_t *options); 326 #endif /* !CONFIG_SCHED_SMT */ 327 328 extern bool sched_SMT_balance( 329 processor_t processor, 330 processor_set_t pset); 331 332 extern void thread_quantum_init( 333 thread_t thread, 334 uint64_t now); 335 336 337 extern void run_queue_init( 338 run_queue_t runq); 339 340 extern thread_t run_queue_dequeue( 341 run_queue_t runq, 342 sched_options_t options); 343 344 extern boolean_t run_queue_enqueue( 345 run_queue_t runq, 346 thread_t thread, 347 sched_options_t options); 348 349 extern void run_queue_remove( 350 run_queue_t runq, 351 thread_t thread); 352 353 extern thread_t run_queue_peek( 354 run_queue_t runq); 355 356 struct sched_update_scan_context { 357 uint64_t earliest_bg_make_runnable_time; 358 uint64_t earliest_normal_make_runnable_time; 359 uint64_t earliest_rt_make_runnable_time; 360 uint64_t sched_tick_last_abstime; 361 }; 362 typedef struct sched_update_scan_context *sched_update_scan_context_t; 363 364 365 extern void sched_pset_made_schedulable( 366 processor_t processor, 367 processor_set_t pset, 368 boolean_t drop_lock); 369 370 extern void sched_cpu_init_completed(void); 371 372 /* 373 * Enum to define various events which need IPIs. The IPI policy 374 * engine decides what kind of IPI to use based on destination 375 * processor state, thread and one of the following scheduling events. 376 */ 377 typedef enum { 378 SCHED_IPI_EVENT_BOUND_THR = 0x1, 379 SCHED_IPI_EVENT_PREEMPT = 0x2, 380 SCHED_IPI_EVENT_SMT_REBAL = 0x3, 381 SCHED_IPI_EVENT_SPILL = 0x4, 382 SCHED_IPI_EVENT_REBALANCE = 0x5, 383 SCHED_IPI_EVENT_RT_PREEMPT = 0x6, 384 } sched_ipi_event_t; 385 386 387 /* Enum to define various IPI types used by the scheduler */ 388 typedef enum { 389 SCHED_IPI_NONE = 0x0, 390 SCHED_IPI_IMMEDIATE = 0x1, 391 SCHED_IPI_IDLE = 0x2, 392 SCHED_IPI_DEFERRED = 0x3, 393 } sched_ipi_type_t; 394 395 /* The IPI policy engine behaves in the following manner: 396 * - All scheduler events which need an IPI invoke sched_ipi_action() with 397 * the appropriate destination processor, thread and event. 398 * - sched_ipi_action() performs basic checks, invokes the scheduler specific 399 * ipi_policy routine and sets pending_AST bits based on the result. 400 * - Once the pset lock is dropped, the scheduler invokes sched_ipi_perform() 401 * routine which actually sends the appropriate IPI to the destination core. 402 */ 403 extern sched_ipi_type_t sched_ipi_action(processor_t dst, thread_t thread, sched_ipi_event_t event); 404 extern void sched_ipi_perform(processor_t dst, sched_ipi_type_t ipi); 405 406 /* sched_ipi_policy() is the global default IPI policy for all schedulers */ 407 extern sched_ipi_type_t sched_ipi_policy(processor_t dst, thread_t thread, 408 boolean_t dst_idle, sched_ipi_event_t event); 409 410 /* sched_ipi_deferred_policy() is the global default deferred IPI policy for all schedulers */ 411 extern sched_ipi_type_t sched_ipi_deferred_policy(processor_set_t pset, 412 processor_t dst, thread_t thread, sched_ipi_event_t event); 413 414 #if defined(CONFIG_SCHED_TIMESHARE_CORE) 415 416 extern boolean_t thread_update_add_thread(thread_t thread); 417 extern void thread_update_process_threads(void); 418 extern boolean_t runq_scan(run_queue_t runq, sched_update_scan_context_t scan_context); 419 420 #if CONFIG_SCHED_CLUTCH 421 extern boolean_t sched_clutch_timeshare_scan(queue_t thread_queue, uint16_t count, sched_update_scan_context_t scan_context); 422 #endif /* CONFIG_SCHED_CLUTCH */ 423 424 extern void sched_timeshare_init(void); 425 extern void sched_timeshare_timebase_init(void); 426 extern void sched_timeshare_maintenance_continue(void); 427 428 429 430 extern boolean_t priority_is_urgent(int priority); 431 extern uint32_t sched_timeshare_initial_quantum_size(thread_t thread); 432 433 extern int sched_compute_timeshare_priority(thread_t thread); 434 435 #endif /* CONFIG_SCHED_TIMESHARE_CORE */ 436 437 /* Remove thread from its run queue */ 438 extern boolean_t thread_run_queue_remove(thread_t thread); 439 thread_t thread_run_queue_remove_for_handoff(thread_t thread); 440 441 /* Put a thread back in the run queue after being yanked */ 442 extern void thread_run_queue_reinsert(thread_t thread, sched_options_t options); 443 444 extern void thread_timer_expire( 445 void *thread, 446 void *p1); 447 448 extern bool thread_is_eager_preempt(thread_t thread); 449 450 extern boolean_t sched_generic_direct_dispatch_to_idle_processors; 451 452 /* Set the maximum interrupt level for the thread */ 453 __private_extern__ wait_interrupt_t thread_interrupt_level( 454 wait_interrupt_t interruptible); 455 456 __private_extern__ wait_result_t thread_mark_wait_locked( 457 thread_t thread, 458 wait_interrupt_t interruptible); 459 460 /* Wake up locked thread directly, passing result */ 461 __private_extern__ kern_return_t clear_wait_internal( 462 thread_t thread, 463 wait_result_t result); 464 465 struct sched_statistics { 466 uint32_t csw_count; 467 uint32_t preempt_count; 468 uint32_t preempted_rt_count; 469 uint32_t preempted_by_rt_count; 470 uint32_t rt_sched_count; 471 uint32_t interrupt_count; 472 uint32_t ipi_count; 473 uint32_t timer_pop_count; 474 uint32_t idle_transitions; 475 uint32_t quantum_timer_expirations; 476 }; 477 PERCPU_DECL(struct sched_statistics, sched_stats); 478 extern bool sched_stats_active; 479 480 extern void sched_stats_handle_csw( 481 processor_t processor, 482 int reasons, 483 int selfpri, 484 int otherpri); 485 486 extern void sched_stats_handle_runq_change( 487 struct runq_stats *stats, 488 int old_count); 489 490 #define SCHED_STATS_INC(field) \ 491 MACRO_BEGIN \ 492 if (__improbable(sched_stats_active)) { \ 493 PERCPU_GET(sched_stats)->field++; \ 494 } \ 495 MACRO_END 496 497 #if DEBUG 498 499 #define SCHED_STATS_CSW(processor, reasons, selfpri, otherpri) \ 500 MACRO_BEGIN \ 501 if (__improbable(sched_stats_active)) { \ 502 sched_stats_handle_csw((processor), \ 503 (reasons), (selfpri), (otherpri)); \ 504 } \ 505 MACRO_END 506 507 508 #define SCHED_STATS_RUNQ_CHANGE(stats, old_count) \ 509 MACRO_BEGIN \ 510 if (__improbable(sched_stats_active)) { \ 511 sched_stats_handle_runq_change((stats), (old_count)); \ 512 } \ 513 MACRO_END 514 515 #else /* DEBUG */ 516 517 #define SCHED_STATS_CSW(processor, reasons, selfpri, otherpri) do { }while(0) 518 #define SCHED_STATS_RUNQ_CHANGE(stats, old_count) do { }while(0) 519 520 #endif /* DEBUG */ 521 522 extern uint32_t sched_debug_flags; 523 #define SCHED_DEBUG_FLAG_PLATFORM_TRACEPOINTS 0x00000001 524 #define SCHED_DEBUG_FLAG_CHOOSE_PROCESSOR_TRACEPOINTS 0x00000002 525 #define SCHED_DEBUG_FLAG_AST_CHECK_TRACEPOINTS 0x00000004 526 527 #define SCHED_DEBUG_PLATFORM_KERNEL_DEBUG_CONSTANT(...) \ 528 MACRO_BEGIN \ 529 if (__improbable(sched_debug_flags & \ 530 SCHED_DEBUG_FLAG_PLATFORM_TRACEPOINTS)) { \ 531 KERNEL_DEBUG_CONSTANT(__VA_ARGS__); \ 532 } \ 533 MACRO_END 534 535 #define SCHED_DEBUG_CHOOSE_PROCESSOR_KERNEL_DEBUG_CONSTANT_IST(...) \ 536 MACRO_BEGIN \ 537 if (__improbable(sched_debug_flags & \ 538 SCHED_DEBUG_FLAG_CHOOSE_PROCESSOR_TRACEPOINTS)) { \ 539 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, __VA_ARGS__); \ 540 } \ 541 MACRO_END 542 543 #define SCHED_DEBUG_AST_CHECK_KDBG_RELEASE(...) \ 544 MACRO_BEGIN \ 545 if (__improbable(sched_debug_flags & \ 546 SCHED_DEBUG_FLAG_AST_CHECK_TRACEPOINTS)) { \ 547 KDBG_RELEASE(__VA_ARGS__); \ 548 } \ 549 MACRO_END 550 551 552 /* Tells if there are "active" RT threads in the system (provided by CPU PM) */ 553 extern void active_rt_threads( 554 boolean_t active); 555 556 /* Returns the perfcontrol attribute for the thread */ 557 extern perfcontrol_class_t thread_get_perfcontrol_class( 558 thread_t thread); 559 560 /* Generic routine for Non-AMP schedulers to calculate parallelism */ 561 extern uint32_t sched_qos_max_parallelism(int qos, uint64_t options); 562 563 extern void check_monotonic_time(uint64_t ctime); 564 565 #endif /* defined(MACH_KERNEL_PRIVATE) || SCHED_TEST_HARNESS */ 566 567 __BEGIN_DECLS 568 569 #ifdef XNU_KERNEL_PRIVATE 570 571 extern kern_return_t thread_soft_bind_cluster_type(thread_t, char cluster_type); 572 573 __options_decl(thread_bind_option_t, uint64_t, { 574 /* Unbind a previously cluster bound thread */ 575 THREAD_UNBIND = 0x1, 576 /* 577 * Bind thread to the cluster only if it is eligible to run on that cluster. If 578 * the thread is not eligible to run on the cluster, thread_soft_bind_cluster_id() 579 * returns KERN_INVALID_POLICY. 580 */ 581 THREAD_BIND_ELIGIBLE_ONLY = 0x2, 582 }); 583 extern kern_return_t thread_soft_bind_cluster_id(thread_t thread, uint32_t cluster_id, thread_bind_option_t options); 584 585 extern int sched_get_rt_n_backup_processors(void); 586 extern void sched_set_rt_n_backup_processors(int n); 587 588 extern int sched_get_rt_deadline_epsilon(void); 589 extern void sched_set_rt_deadline_epsilon(int new_epsilon_us); 590 591 /* Toggles a global override to turn off CPU Throttling */ 592 extern void sys_override_cpu_throttle(boolean_t enable_override); 593 594 extern int sched_get_powered_cores(void); 595 extern void sched_set_powered_cores(int n); 596 597 uint64_t sched_sysctl_get_recommended_cores(void); 598 599 /* 600 ****************** Only exported until BSD stops using ******************** 601 */ 602 603 extern void thread_vm_bind_group_add(void); 604 605 /* Wake up thread directly, passing result */ 606 extern kern_return_t clear_wait( 607 thread_t thread, 608 wait_result_t result); 609 610 /* Start thread running */ 611 extern void thread_bootstrap_return(void) __attribute__((noreturn)); 612 613 /* Return from exception (BSD-visible interface) */ 614 extern void thread_exception_return(void) __dead2; 615 616 #define SCHED_STRING_MAX_LENGTH (48) 617 /* String declaring the name of the current scheduler */ 618 extern char sched_string[SCHED_STRING_MAX_LENGTH]; 619 620 __options_decl(thread_handoff_option_t, uint32_t, { 621 THREAD_HANDOFF_NONE = 0, 622 THREAD_HANDOFF_SETRUN_NEEDED = 0x1, 623 }); 624 625 /* Remove thread from its run queue */ 626 thread_t thread_prepare_for_handoff(thread_t thread, thread_handoff_option_t option); 627 628 /* Attempt to context switch to a specific runnable thread */ 629 extern wait_result_t thread_handoff_deallocate(thread_t thread, thread_handoff_option_t option); 630 631 __attribute__((nonnull(2))) 632 extern void thread_handoff_parameter(thread_t thread, 633 thread_continue_t continuation, void *parameter, thread_handoff_option_t) __dead2; 634 635 extern struct waitq *assert_wait_queue(event_t event); 636 637 /* 638 * sched_cond_t: 639 * 640 * A atomic condition variable used to synchronize wake/block operations on threads. 641 * Bits defined below are reserved for use by sched_prim. Remaining 642 * bits may be used by caller for additional synchronization semantics. 643 */ 644 __options_decl(sched_cond_t, uint32_t, { 645 SCHED_COND_INIT = 0x0000, /* initialize all bits to zero (inactive and not awoken) */ 646 SCHED_COND_ACTIVE = 0x0001, /* target thread is active */ 647 SCHED_COND_WAKEUP = 0x0002 /* wakeup has been issued for target thread */ 648 }); 649 typedef _Atomic sched_cond_t sched_cond_atomic_t; 650 651 /* 652 * sched_cond_init: 653 * 654 * Initialize an atomic condition variable. Note that this does not occur atomically and should be 655 * performed during thread initialization, before the condition is observable by other threads. 656 */ 657 extern void sched_cond_init( 658 sched_cond_atomic_t *cond); 659 660 /* 661 * sched_cond_signal: 662 * 663 * Wakeup the specified thread if it is waiting on this event and it has not already been issued a wakeup. 664 * 665 * parameters: 666 * thread thread to awaken 667 * cond atomic condition variable 668 */ 669 extern kern_return_t sched_cond_signal( 670 sched_cond_atomic_t *cond, 671 thread_t thread); 672 673 /* 674 * sched_cond_wait_parameter: 675 * 676 * Assert wait and block on cond if no wakeup has been issued. 677 * If a wakeup has been issued on cond since the last `sched_cond_ack`, clear_wait and 678 * return `THREAD_AWAKENED`. 679 * 680 * `sched_cond_wait_parameter` must be paired with `sched_cond_ack`. 681 * 682 * NOTE: `continuation` will only be jumped to if a wakeup has not been issued 683 * 684 * parameters: 685 * cond atomic condition variable to synchronize on 686 * interruptible interruptible value to pass to assert_wait 687 * continuation continuation if block succeeds 688 * parameter 689 */ 690 extern wait_result_t sched_cond_wait_parameter( 691 sched_cond_atomic_t *cond, 692 wait_interrupt_t interruptible, 693 thread_continue_t continuation, 694 void *parameter); 695 696 /* 697 * sched_cond_wait: 698 * 699 * Assert wait and block on cond if no wakeup has been issued. 700 * If a wakeup has been issued on cond since the last `sched_cond_ack`, clear_wait and 701 * return `THREAD_AWAKENED`. 702 * 703 * `sched_cond_wait` must be paired with `sched_cond_ack`. 704 * 705 * NOTE: `continuation` will only be jumped to if a wakeup has not been issued 706 * 707 * parameters: 708 * cond atomic condition variable to synchronize on 709 * interruptible interruptible value to pass to assert_wait 710 * continuation continuation if block succeeds 711 */ 712 extern wait_result_t sched_cond_wait( 713 sched_cond_atomic_t *cond, 714 wait_interrupt_t interruptible, 715 thread_continue_t continuation); 716 717 /* 718 * sched_cond_ack: 719 * 720 * Acknowledge an issued wakeup by clearing WAKEUP and setting ACTIVE (via XOR). 721 * It is the callers responsibility to ensure that the ACTIVE bit is always low prior to calling 722 * (i.e. by calling `sched_cond_wait` prior to any rerun or block). 723 * Synchronization schemes that allow for WAKEUP bit to be reset prior to wakeup 724 * (e.g. a cancellation mechanism) should check that WAKEUP was indeed cleared. 725 * 726 * e.g. 727 * ``` 728 * if (sched_cond_ack(&my_state) & SCHED_THREAD_WAKEUP) { 729 * // WAKEUP bit was no longer set by the time this thread woke up 730 * do_cancellation_policy(); 731 * } 732 * ``` 733 * 734 * parameters: 735 * cond: atomic condition variable 736 */ 737 extern sched_cond_t sched_cond_ack( 738 sched_cond_atomic_t *cond); 739 740 #endif /* XNU_KERNEL_PRIVATE */ 741 742 #if defined(KERNEL_PRIVATE) || SCHED_TEST_HARNESS 743 /* Set pending block hint for a particular object before we go into a wait state */ 744 extern void thread_set_pending_block_hint( 745 thread_t thread, 746 block_hint_t block_hint); 747 748 #define QOS_PARALLELISM_COUNT_LOGICAL 0x1 749 #define QOS_PARALLELISM_REALTIME 0x2 750 #define QOS_PARALLELISM_CLUSTER_SHARED_RESOURCE 0x4 751 752 extern uint32_t qos_max_parallelism(int qos, uint64_t options); 753 #endif /* defined(KERNEL_PRIVATE) || SCHED_TEST_HARNESS */ 754 755 #if XNU_KERNEL_PRIVATE 756 extern void thread_yield_with_continuation( 757 thread_continue_t continuation, 758 void *parameter) __dead2; 759 #endif /* XNU_KERNEL_PRIVATE */ 760 761 /* Context switch */ 762 extern wait_result_t thread_block( 763 thread_continue_t continuation); 764 765 extern wait_result_t thread_block_parameter( 766 thread_continue_t continuation, 767 void *parameter); 768 769 /* Declare thread will wait on a particular event */ 770 extern wait_result_t assert_wait( 771 event_t event, 772 wait_interrupt_t interruptible); 773 774 /* Assert that the thread intends to wait with a timeout */ 775 extern wait_result_t assert_wait_timeout( 776 event_t event, 777 wait_interrupt_t interruptible, 778 uint32_t interval, 779 uint32_t scale_factor); 780 781 /* Assert that the thread intends to wait with an urgency, timeout and leeway */ 782 extern wait_result_t assert_wait_timeout_with_leeway( 783 event_t event, 784 wait_interrupt_t interruptible, 785 wait_timeout_urgency_t urgency, 786 uint32_t interval, 787 uint32_t leeway, 788 uint32_t scale_factor); 789 790 extern wait_result_t assert_wait_deadline( 791 event_t event, 792 wait_interrupt_t interruptible, 793 uint64_t deadline); 794 795 /* Assert that the thread intends to wait with an urgency, deadline, and leeway */ 796 extern wait_result_t assert_wait_deadline_with_leeway( 797 event_t event, 798 wait_interrupt_t interruptible, 799 wait_timeout_urgency_t urgency, 800 uint64_t deadline, 801 uint64_t leeway); 802 803 804 /* Wake up thread (or threads) waiting on a particular event */ 805 extern kern_return_t thread_wakeup_prim( 806 event_t event, 807 boolean_t one_thread, 808 wait_result_t result); 809 810 /* Wake up up to given number of threads waiting on a particular event */ 811 extern kern_return_t thread_wakeup_nthreads_prim( 812 event_t event, 813 uint32_t nthreads, 814 wait_result_t result); 815 816 #define thread_wakeup(x) \ 817 thread_wakeup_prim((x), FALSE, THREAD_AWAKENED) 818 #define thread_wakeup_with_result(x, z) \ 819 thread_wakeup_prim((x), FALSE, (z)) 820 #define thread_wakeup_one(x) \ 821 thread_wakeup_prim((x), TRUE, THREAD_AWAKENED) 822 823 #define thread_wakeup_nthreads(x, nthreads) \ 824 thread_wakeup_nthreads_prim((x), (nthreads), THREAD_AWAKENED) 825 #define thread_wakeup_nthreads_with_result(x, nthreads, z) \ 826 thread_wakeup_nthreads_prim((x), (nthreads), (z)) 827 828 /* Wakeup the specified thread if it is waiting on this event */ 829 extern kern_return_t thread_wakeup_thread(event_t event, thread_t thread); 830 831 extern boolean_t preemption_enabled(void); 832 833 #if defined(MACH_KERNEL_PRIVATE) || SCHED_TEST_HARNESS 834 835 836 #if !CONFIG_SCHED_TIMESHARE_CORE && !CONFIG_SCHED_CLUTCH && !CONFIG_SCHED_EDGE 837 #error Enable at least one scheduler algorithm in osfmk/conf/MASTER.XXX 838 #endif 839 840 /* 841 * The scheduling policy is fixed at compile-time, in order to save the performance 842 * cost of function pointer indirection that we would otherwise pay each time when 843 * making a policy-specific callout. 844 */ 845 #if __AMP__ 846 847 #if CONFIG_SCHED_EDGE 848 extern const struct sched_dispatch_table sched_edge_dispatch; 849 #define SCHED(f) (sched_edge_dispatch.f) 850 #else /* CONFIG_SCHED_EDGE */ 851 extern const struct sched_dispatch_table sched_amp_dispatch; 852 #define SCHED(f) (sched_amp_dispatch.f) 853 #endif /* CONFIG_SCHED_EDGE */ 854 855 #else /* __AMP__ */ 856 857 #if CONFIG_SCHED_CLUTCH 858 extern const struct sched_dispatch_table sched_clutch_dispatch; 859 #define SCHED(f) (sched_clutch_dispatch.f) 860 #else /* CONFIG_SCHED_CLUTCH */ 861 extern const struct sched_dispatch_table sched_dualq_dispatch; 862 #define SCHED(f) (sched_dualq_dispatch.f) 863 #endif /* CONFIG_SCHED_CLUTCH */ 864 865 #endif /* __AMP__ */ 866 867 struct sched_dispatch_table { 868 const char *sched_name; 869 void (*init)(void); /* Init global state */ 870 void (*timebase_init)(void); /* Timebase-dependent initialization */ 871 void (*processor_init)(processor_t processor); /* Per-processor scheduler init */ 872 void (*pset_init)(processor_set_t pset); /* Per-processor set scheduler init */ 873 874 void (*maintenance_continuation)(void); /* Function called regularly */ 875 876 /* 877 * Choose a thread of greater or equal priority from the per-processor 878 * runqueue for timeshare/fixed threads 879 */ 880 thread_t (*choose_thread)( 881 processor_t processor, 882 int priority, 883 thread_t prev_thread, 884 ast_t reason); 885 886 /* True if scheduler supports stealing threads for this pset */ 887 bool (*steal_thread_enabled)(processor_set_t pset); 888 889 /* 890 * Steal a thread from another processor in the pset so that it can run 891 * immediately 892 */ 893 thread_t (*steal_thread)( 894 processor_set_t pset); 895 896 /* 897 * Compute priority for a timeshare thread based on base priority. 898 */ 899 int (*compute_timeshare_priority)(thread_t thread); 900 901 /* 902 * Pick the best node for a thread to run on. 903 */ 904 pset_node_t (*choose_node)( 905 thread_t thread); 906 907 /* 908 * Pick the best processor for a thread (any kind of thread) to run on. 909 */ 910 processor_t (*choose_processor)( 911 processor_set_t pset, 912 processor_t processor, 913 thread_t thread, 914 sched_options_t *options); 915 916 /* 917 * Enqueue a timeshare or fixed priority thread onto the per-processor 918 * runqueue 919 */ 920 boolean_t (*processor_enqueue)( 921 processor_t processor, 922 thread_t thread, 923 sched_options_t options); 924 925 /* Migrate threads away in preparation for processor shutdown */ 926 void (*processor_queue_shutdown)( 927 processor_t processor); 928 929 /* Remove the specific thread from the per-processor runqueue */ 930 boolean_t (*processor_queue_remove)( 931 processor_t processor, 932 thread_t thread); 933 934 /* 935 * Does the per-processor runqueue have any timeshare or fixed priority 936 * threads on it? Called without pset lock held, so should 937 * not assume immutability while executing. 938 */ 939 boolean_t (*processor_queue_empty)(processor_t processor); 940 941 /* 942 * Would this priority trigger an urgent preemption if it's sitting 943 * on the per-processor runqueue? 944 */ 945 boolean_t (*priority_is_urgent)(int priority); 946 947 /* 948 * Does the per-processor runqueue contain runnable threads that 949 * should cause the currently-running thread to be preempted? 950 */ 951 ast_t (*processor_csw_check)(processor_t processor); 952 953 /* 954 * Does the per-processor runqueue contain a runnable thread 955 * of > or >= priority, as a preflight for choose_thread() or other 956 * thread selection 957 */ 958 boolean_t (*processor_queue_has_priority)(processor_t processor, 959 int priority, 960 boolean_t gte); 961 962 /* Quantum size for the specified non-realtime thread. */ 963 uint32_t (*initial_quantum_size)(thread_t thread); 964 965 /* Scheduler mode for a new thread */ 966 sched_mode_t (*initial_thread_sched_mode)(task_t parent_task); 967 968 /* 969 * Is it safe to call update_priority, which may change a thread's 970 * runqueue or other state. This can be used to throttle changes 971 * to dynamic priority. 972 */ 973 boolean_t (*can_update_priority)(thread_t thread); 974 975 /* 976 * Update both scheduled priority and other persistent state. 977 * Side effects may including migration to another processor's runqueue. 978 */ 979 void (*update_priority)(thread_t thread); 980 981 /* Lower overhead update to scheduled priority and state. */ 982 void (*lightweight_update_priority)(thread_t thread); 983 984 /* Callback for non-realtime threads when the quantum timer fires */ 985 void (*quantum_expire)(thread_t thread); 986 987 /* 988 * Runnable threads on per-processor runqueue. Should only 989 * be used for relative comparisons of load between processors. 990 */ 991 int (*processor_runq_count)(processor_t processor); 992 993 /* Aggregate runcount statistics for per-processor runqueue */ 994 uint64_t (*processor_runq_stats_count_sum)(processor_t processor); 995 996 boolean_t (*processor_bound_count)(processor_t processor); 997 998 void (*thread_update_scan)(sched_update_scan_context_t scan_context); 999 1000 /* Supports more than one pset */ 1001 boolean_t multiple_psets_enabled; 1002 1003 /* Supports avoid-processor */ 1004 boolean_t avoid_processor_enabled; 1005 1006 /* Returns true if this processor should avoid running this thread. */ 1007 bool (*thread_avoid_processor)(processor_t processor, thread_t thread, ast_t reason); 1008 1009 /* 1010 * Invoked when a processor is about to choose the idle thread 1011 * Used to send IPIs to a processor which would be preferred to be idle instead. 1012 * Returns true if the current processor should anticipate a quick IPI reply back 1013 * from another core. 1014 * Called with pset lock held, returns with pset lock unlocked. 1015 */ 1016 bool (*processor_balance)(processor_t processor, processor_set_t pset); 1017 1018 processor_t (*rt_choose_processor)(processor_set_t starting_pset, processor_t starting_processor, thread_t thread); 1019 thread_t (*rt_steal_thread)(processor_set_t stealing_pset); 1020 void (*rt_init_pset)(processor_set_t pset); 1021 void (*rt_init_completed)(void); 1022 void (*rt_queue_shutdown)(processor_t processor); 1023 void (*rt_runq_scan)(sched_update_scan_context_t scan_context); 1024 int64_t (*rt_runq_count_sum)(void); 1025 1026 uint32_t (*qos_max_parallelism)(int qos, uint64_t options); 1027 void (*check_spill)(processor_set_t pset, thread_t thread); 1028 sched_ipi_type_t (*ipi_policy)(processor_t dst, thread_t thread, boolean_t dst_idle, sched_ipi_event_t event); 1029 bool (*thread_should_yield)(processor_t processor, thread_t thread); 1030 1031 /* Routine to update run counts */ 1032 uint32_t (*run_count_incr)(thread_t thread); 1033 uint32_t (*run_count_decr)(thread_t thread); 1034 1035 /* Routine to update scheduling bucket for a thread */ 1036 void (*update_thread_bucket)(thread_t thread); 1037 1038 /* Routine to inform the scheduler when a new pset becomes schedulable */ 1039 void (*pset_made_schedulable)(processor_t processor, processor_set_t pset, boolean_t drop_lock); 1040 #if CONFIG_THREAD_GROUPS 1041 /* Routine to inform the scheduler when CLPC changes a thread group recommendation */ 1042 void (*thread_group_recommendation_change)(struct thread_group *tg, cluster_type_t new_recommendation); 1043 #endif 1044 /* Routine to inform the scheduler when all CPUs have finished initializing */ 1045 void (*cpu_init_completed)(void); 1046 /* Routine to check if a thread is eligible to execute on a specific pset */ 1047 bool (*thread_eligible_for_pset)(thread_t thread, processor_set_t pset); 1048 }; 1049 1050 extern const struct sched_dispatch_table sched_dualq_dispatch; 1051 #if __AMP__ 1052 extern const struct sched_dispatch_table sched_amp_dispatch; 1053 #endif 1054 1055 #if defined(CONFIG_SCHED_CLUTCH) 1056 extern const struct sched_dispatch_table sched_clutch_dispatch; 1057 #endif 1058 1059 #if defined(CONFIG_SCHED_EDGE) 1060 extern const struct sched_dispatch_table sched_edge_dispatch; 1061 #endif 1062 1063 extern void sched_set_max_unsafe_rt_quanta(int max); 1064 extern void sched_set_max_unsafe_fixed_quanta(int max); 1065 1066 #endif /* defined(MACH_KERNEL_PRIVATE) || SCHED_TEST_HARNESS */ 1067 1068 __END_DECLS 1069 1070 #endif /* _KERN_SCHED_PRIM_H_ */ 1071