1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SCHED_H 3 #define _LINUX_SCHED_H 4 5 /* 6 * Define 'struct task_struct' and provide the main scheduler 7 * APIs (schedule(), wakeup variants, etc.) 8 */ 9 10 #include <uapi/linux/sched.h> 11 12 #include <asm/current.h> 13 #include <asm/processor.h> 14 #include <linux/thread_info.h> 15 #include <linux/preempt.h> 16 #include <linux/cpumask.h> 17 18 #include <linux/cache.h> 19 #include <linux/irqflags_types.h> 20 #include <linux/smp_types.h> 21 #include <linux/pid_types.h> 22 #include <linux/sem_types.h> 23 #include <linux/shm.h> 24 #include <linux/kmsan_types.h> 25 #include <linux/mutex_types.h> 26 #include <linux/plist_types.h> 27 #include <linux/hrtimer_types.h> 28 #include <linux/timer_types.h> 29 #include <linux/seccomp_types.h> 30 #include <linux/nodemask_types.h> 31 #include <linux/refcount_types.h> 32 #include <linux/resource.h> 33 #include <linux/latencytop.h> 34 #include <linux/sched/prio.h> 35 #include <linux/sched/types.h> 36 #include <linux/signal_types.h> 37 #include <linux/syscall_user_dispatch_types.h> 38 #include <linux/mm_types_task.h> 39 #include <linux/task_io_accounting.h> 40 #include <linux/posix-timers_types.h> 41 #include <linux/restart_block.h> 42 #include <uapi/linux/rseq.h> 43 #include <linux/seqlock_types.h> 44 #include <linux/kcsan.h> 45 #include <linux/rv.h> 46 #include <linux/livepatch_sched.h> 47 #include <linux/uidgid_types.h> 48 #include <asm/kmap_size.h> 49 50 /* task_struct member predeclarations (sorted alphabetically): */ 51 struct audit_context; 52 struct bio_list; 53 struct blk_plug; 54 struct bpf_local_storage; 55 struct bpf_run_ctx; 56 struct capture_control; 57 struct cfs_rq; 58 struct fs_struct; 59 struct futex_pi_state; 60 struct io_context; 61 struct io_uring_task; 62 struct mempolicy; 63 struct nameidata; 64 struct nsproxy; 65 struct perf_event_context; 66 struct pid_namespace; 67 struct pipe_inode_info; 68 struct rcu_node; 69 struct reclaim_state; 70 struct robust_list_head; 71 struct root_domain; 72 struct rq; 73 struct sched_attr; 74 struct sched_dl_entity; 75 struct seq_file; 76 struct sighand_struct; 77 struct signal_struct; 78 struct task_delay_info; 79 struct task_group; 80 struct task_struct; 81 struct user_event_mm; 82 83 /* 84 * Task state bitmask. NOTE! These bits are also 85 * encoded in fs/proc/array.c: get_task_state(). 86 * 87 * We have two separate sets of flags: task->__state 88 * is about runnability, while task->exit_state are 89 * about the task exiting. Confusing, but this way 90 * modifying one set can't modify the other one by 91 * mistake. 92 */ 93 94 /* Used in tsk->__state: */ 95 #define TASK_RUNNING 0x00000000 96 #define TASK_INTERRUPTIBLE 0x00000001 97 #define TASK_UNINTERRUPTIBLE 0x00000002 98 #define __TASK_STOPPED 0x00000004 99 #define __TASK_TRACED 0x00000008 100 /* Used in tsk->exit_state: */ 101 #define EXIT_DEAD 0x00000010 102 #define EXIT_ZOMBIE 0x00000020 103 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 104 /* Used in tsk->__state again: */ 105 #define TASK_PARKED 0x00000040 106 #define TASK_DEAD 0x00000080 107 #define TASK_WAKEKILL 0x00000100 108 #define TASK_WAKING 0x00000200 109 #define TASK_NOLOAD 0x00000400 110 #define TASK_NEW 0x00000800 111 #define TASK_RTLOCK_WAIT 0x00001000 112 #define TASK_FREEZABLE 0x00002000 113 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 114 #define TASK_FROZEN 0x00008000 115 #define TASK_STATE_MAX 0x00010000 116 117 #define TASK_ANY (TASK_STATE_MAX-1) 118 119 /* 120 * DO NOT ADD ANY NEW USERS ! 121 */ 122 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 123 124 /* Convenience macros for the sake of set_current_state: */ 125 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 126 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 127 #define TASK_TRACED __TASK_TRACED 128 129 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 130 131 /* Convenience macros for the sake of wake_up(): */ 132 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 133 134 /* get_task_state(): */ 135 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 136 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 137 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 138 TASK_PARKED) 139 140 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 141 142 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 143 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 144 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 145 146 /* 147 * Special states are those that do not use the normal wait-loop pattern. See 148 * the comment with set_special_state(). 149 */ 150 #define is_special_task_state(state) \ 151 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 152 153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 154 # define debug_normal_state_change(state_value) \ 155 do { \ 156 WARN_ON_ONCE(is_special_task_state(state_value)); \ 157 current->task_state_change = _THIS_IP_; \ 158 } while (0) 159 160 # define debug_special_state_change(state_value) \ 161 do { \ 162 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 163 current->task_state_change = _THIS_IP_; \ 164 } while (0) 165 166 # define debug_rtlock_wait_set_state() \ 167 do { \ 168 current->saved_state_change = current->task_state_change;\ 169 current->task_state_change = _THIS_IP_; \ 170 } while (0) 171 172 # define debug_rtlock_wait_restore_state() \ 173 do { \ 174 current->task_state_change = current->saved_state_change;\ 175 } while (0) 176 177 #else 178 # define debug_normal_state_change(cond) do { } while (0) 179 # define debug_special_state_change(cond) do { } while (0) 180 # define debug_rtlock_wait_set_state() do { } while (0) 181 # define debug_rtlock_wait_restore_state() do { } while (0) 182 #endif 183 184 /* 185 * set_current_state() includes a barrier so that the write of current->__state 186 * is correctly serialised wrt the caller's subsequent test of whether to 187 * actually sleep: 188 * 189 * for (;;) { 190 * set_current_state(TASK_UNINTERRUPTIBLE); 191 * if (CONDITION) 192 * break; 193 * 194 * schedule(); 195 * } 196 * __set_current_state(TASK_RUNNING); 197 * 198 * If the caller does not need such serialisation (because, for instance, the 199 * CONDITION test and condition change and wakeup are under the same lock) then 200 * use __set_current_state(). 201 * 202 * The above is typically ordered against the wakeup, which does: 203 * 204 * CONDITION = 1; 205 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 206 * 207 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 208 * accessing p->__state. 209 * 210 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is, 211 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 212 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 213 * 214 * However, with slightly different timing the wakeup TASK_RUNNING store can 215 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 216 * a problem either because that will result in one extra go around the loop 217 * and our @cond test will save the day. 218 * 219 * Also see the comments of try_to_wake_up(). 220 */ 221 #define __set_current_state(state_value) \ 222 do { \ 223 debug_normal_state_change((state_value)); \ 224 WRITE_ONCE(current->__state, (state_value)); \ 225 } while (0) 226 227 #define set_current_state(state_value) \ 228 do { \ 229 debug_normal_state_change((state_value)); \ 230 smp_store_mb(current->__state, (state_value)); \ 231 } while (0) 232 233 /* 234 * set_special_state() should be used for those states when the blocking task 235 * can not use the regular condition based wait-loop. In that case we must 236 * serialize against wakeups such that any possible in-flight TASK_RUNNING 237 * stores will not collide with our state change. 238 */ 239 #define set_special_state(state_value) \ 240 do { \ 241 unsigned long flags; /* may shadow */ \ 242 \ 243 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 244 debug_special_state_change((state_value)); \ 245 WRITE_ONCE(current->__state, (state_value)); \ 246 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 247 } while (0) 248 249 /* 250 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 251 * 252 * RT's spin/rwlock substitutions are state preserving. The state of the 253 * task when blocking on the lock is saved in task_struct::saved_state and 254 * restored after the lock has been acquired. These operations are 255 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 256 * lock related wakeups while the task is blocked on the lock are 257 * redirected to operate on task_struct::saved_state to ensure that these 258 * are not dropped. On restore task_struct::saved_state is set to 259 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 260 * 261 * The lock operation looks like this: 262 * 263 * current_save_and_set_rtlock_wait_state(); 264 * for (;;) { 265 * if (try_lock()) 266 * break; 267 * raw_spin_unlock_irq(&lock->wait_lock); 268 * schedule_rtlock(); 269 * raw_spin_lock_irq(&lock->wait_lock); 270 * set_current_state(TASK_RTLOCK_WAIT); 271 * } 272 * current_restore_rtlock_saved_state(); 273 */ 274 #define current_save_and_set_rtlock_wait_state() \ 275 do { \ 276 lockdep_assert_irqs_disabled(); \ 277 raw_spin_lock(¤t->pi_lock); \ 278 current->saved_state = current->__state; \ 279 debug_rtlock_wait_set_state(); \ 280 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 281 raw_spin_unlock(¤t->pi_lock); \ 282 } while (0); 283 284 #define current_restore_rtlock_saved_state() \ 285 do { \ 286 lockdep_assert_irqs_disabled(); \ 287 raw_spin_lock(¤t->pi_lock); \ 288 debug_rtlock_wait_restore_state(); \ 289 WRITE_ONCE(current->__state, current->saved_state); \ 290 current->saved_state = TASK_RUNNING; \ 291 raw_spin_unlock(¤t->pi_lock); \ 292 } while (0); 293 294 #define get_current_state() READ_ONCE(current->__state) 295 296 /* 297 * Define the task command name length as enum, then it can be visible to 298 * BPF programs. 299 */ 300 enum { 301 TASK_COMM_LEN = 16, 302 }; 303 304 extern void scheduler_tick(void); 305 306 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 307 308 extern long schedule_timeout(long timeout); 309 extern long schedule_timeout_interruptible(long timeout); 310 extern long schedule_timeout_killable(long timeout); 311 extern long schedule_timeout_uninterruptible(long timeout); 312 extern long schedule_timeout_idle(long timeout); 313 asmlinkage void schedule(void); 314 extern void schedule_preempt_disabled(void); 315 asmlinkage void preempt_schedule_irq(void); 316 #ifdef CONFIG_PREEMPT_RT 317 extern void schedule_rtlock(void); 318 #endif 319 320 extern int __must_check io_schedule_prepare(void); 321 extern void io_schedule_finish(int token); 322 extern long io_schedule_timeout(long timeout); 323 extern void io_schedule(void); 324 325 /** 326 * struct prev_cputime - snapshot of system and user cputime 327 * @utime: time spent in user mode 328 * @stime: time spent in system mode 329 * @lock: protects the above two fields 330 * 331 * Stores previous user/system time values such that we can guarantee 332 * monotonicity. 333 */ 334 struct prev_cputime { 335 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 336 u64 utime; 337 u64 stime; 338 raw_spinlock_t lock; 339 #endif 340 }; 341 342 enum vtime_state { 343 /* Task is sleeping or running in a CPU with VTIME inactive: */ 344 VTIME_INACTIVE = 0, 345 /* Task is idle */ 346 VTIME_IDLE, 347 /* Task runs in kernelspace in a CPU with VTIME active: */ 348 VTIME_SYS, 349 /* Task runs in userspace in a CPU with VTIME active: */ 350 VTIME_USER, 351 /* Task runs as guests in a CPU with VTIME active: */ 352 VTIME_GUEST, 353 }; 354 355 struct vtime { 356 seqcount_t seqcount; 357 unsigned long long starttime; 358 enum vtime_state state; 359 unsigned int cpu; 360 u64 utime; 361 u64 stime; 362 u64 gtime; 363 }; 364 365 /* 366 * Utilization clamp constraints. 367 * @UCLAMP_MIN: Minimum utilization 368 * @UCLAMP_MAX: Maximum utilization 369 * @UCLAMP_CNT: Utilization clamp constraints count 370 */ 371 enum uclamp_id { 372 UCLAMP_MIN = 0, 373 UCLAMP_MAX, 374 UCLAMP_CNT 375 }; 376 377 #ifdef CONFIG_SMP 378 extern struct root_domain def_root_domain; 379 extern struct mutex sched_domains_mutex; 380 #endif 381 382 struct sched_param { 383 int sched_priority; 384 }; 385 386 struct sched_info { 387 #ifdef CONFIG_SCHED_INFO 388 /* Cumulative counters: */ 389 390 /* # of times we have run on this CPU: */ 391 unsigned long pcount; 392 393 /* Time spent waiting on a runqueue: */ 394 unsigned long long run_delay; 395 396 /* Timestamps: */ 397 398 /* When did we last run on a CPU? */ 399 unsigned long long last_arrival; 400 401 /* When were we last queued to run? */ 402 unsigned long long last_queued; 403 404 #endif /* CONFIG_SCHED_INFO */ 405 }; 406 407 /* 408 * Integer metrics need fixed point arithmetic, e.g., sched/fair 409 * has a few: load, load_avg, util_avg, freq, and capacity. 410 * 411 * We define a basic fixed point arithmetic range, and then formalize 412 * all these metrics based on that basic range. 413 */ 414 # define SCHED_FIXEDPOINT_SHIFT 10 415 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 416 417 /* Increase resolution of cpu_capacity calculations */ 418 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 419 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 420 421 struct load_weight { 422 unsigned long weight; 423 u32 inv_weight; 424 }; 425 426 /* 427 * The load/runnable/util_avg accumulates an infinite geometric series 428 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 429 * 430 * [load_avg definition] 431 * 432 * load_avg = runnable% * scale_load_down(load) 433 * 434 * [runnable_avg definition] 435 * 436 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 437 * 438 * [util_avg definition] 439 * 440 * util_avg = running% * SCHED_CAPACITY_SCALE 441 * 442 * where runnable% is the time ratio that a sched_entity is runnable and 443 * running% the time ratio that a sched_entity is running. 444 * 445 * For cfs_rq, they are the aggregated values of all runnable and blocked 446 * sched_entities. 447 * 448 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 449 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 450 * for computing those signals (see update_rq_clock_pelt()) 451 * 452 * N.B., the above ratios (runnable% and running%) themselves are in the 453 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 454 * to as large a range as necessary. This is for example reflected by 455 * util_avg's SCHED_CAPACITY_SCALE. 456 * 457 * [Overflow issue] 458 * 459 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 460 * with the highest load (=88761), always runnable on a single cfs_rq, 461 * and should not overflow as the number already hits PID_MAX_LIMIT. 462 * 463 * For all other cases (including 32-bit kernels), struct load_weight's 464 * weight will overflow first before we do, because: 465 * 466 * Max(load_avg) <= Max(load.weight) 467 * 468 * Then it is the load_weight's responsibility to consider overflow 469 * issues. 470 */ 471 struct sched_avg { 472 u64 last_update_time; 473 u64 load_sum; 474 u64 runnable_sum; 475 u32 util_sum; 476 u32 period_contrib; 477 unsigned long load_avg; 478 unsigned long runnable_avg; 479 unsigned long util_avg; 480 unsigned int util_est; 481 } ____cacheline_aligned; 482 483 /* 484 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 485 * updates. When a task is dequeued, its util_est should not be updated if its 486 * util_avg has not been updated in the meantime. 487 * This information is mapped into the MSB bit of util_est at dequeue time. 488 * Since max value of util_est for a task is 1024 (PELT util_avg for a task) 489 * it is safe to use MSB. 490 */ 491 #define UTIL_EST_WEIGHT_SHIFT 2 492 #define UTIL_AVG_UNCHANGED 0x80000000 493 494 struct sched_statistics { 495 #ifdef CONFIG_SCHEDSTATS 496 u64 wait_start; 497 u64 wait_max; 498 u64 wait_count; 499 u64 wait_sum; 500 u64 iowait_count; 501 u64 iowait_sum; 502 503 u64 sleep_start; 504 u64 sleep_max; 505 s64 sum_sleep_runtime; 506 507 u64 block_start; 508 u64 block_max; 509 s64 sum_block_runtime; 510 511 s64 exec_max; 512 u64 slice_max; 513 514 u64 nr_migrations_cold; 515 u64 nr_failed_migrations_affine; 516 u64 nr_failed_migrations_running; 517 u64 nr_failed_migrations_hot; 518 u64 nr_forced_migrations; 519 520 u64 nr_wakeups; 521 u64 nr_wakeups_sync; 522 u64 nr_wakeups_migrate; 523 u64 nr_wakeups_local; 524 u64 nr_wakeups_remote; 525 u64 nr_wakeups_affine; 526 u64 nr_wakeups_affine_attempts; 527 u64 nr_wakeups_passive; 528 u64 nr_wakeups_idle; 529 530 #ifdef CONFIG_SCHED_CORE 531 u64 core_forceidle_sum; 532 #endif 533 #endif /* CONFIG_SCHEDSTATS */ 534 } ____cacheline_aligned; 535 536 struct sched_entity { 537 /* For load-balancing: */ 538 struct load_weight load; 539 struct rb_node run_node; 540 u64 deadline; 541 u64 min_vruntime; 542 543 struct list_head group_node; 544 unsigned int on_rq; 545 546 u64 exec_start; 547 u64 sum_exec_runtime; 548 u64 prev_sum_exec_runtime; 549 u64 vruntime; 550 s64 vlag; 551 u64 slice; 552 553 u64 nr_migrations; 554 555 #ifdef CONFIG_FAIR_GROUP_SCHED 556 int depth; 557 struct sched_entity *parent; 558 /* rq on which this entity is (to be) queued: */ 559 struct cfs_rq *cfs_rq; 560 /* rq "owned" by this entity/group: */ 561 struct cfs_rq *my_q; 562 /* cached value of my_q->h_nr_running */ 563 unsigned long runnable_weight; 564 #endif 565 566 #ifdef CONFIG_SMP 567 /* 568 * Per entity load average tracking. 569 * 570 * Put into separate cache line so it does not 571 * collide with read-mostly values above. 572 */ 573 struct sched_avg avg; 574 #endif 575 }; 576 577 struct sched_rt_entity { 578 struct list_head run_list; 579 unsigned long timeout; 580 unsigned long watchdog_stamp; 581 unsigned int time_slice; 582 unsigned short on_rq; 583 unsigned short on_list; 584 585 struct sched_rt_entity *back; 586 #ifdef CONFIG_RT_GROUP_SCHED 587 struct sched_rt_entity *parent; 588 /* rq on which this entity is (to be) queued: */ 589 struct rt_rq *rt_rq; 590 /* rq "owned" by this entity/group: */ 591 struct rt_rq *my_q; 592 #endif 593 } __randomize_layout; 594 595 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *); 596 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *); 597 598 struct sched_dl_entity { 599 struct rb_node rb_node; 600 601 /* 602 * Original scheduling parameters. Copied here from sched_attr 603 * during sched_setattr(), they will remain the same until 604 * the next sched_setattr(). 605 */ 606 u64 dl_runtime; /* Maximum runtime for each instance */ 607 u64 dl_deadline; /* Relative deadline of each instance */ 608 u64 dl_period; /* Separation of two instances (period) */ 609 u64 dl_bw; /* dl_runtime / dl_period */ 610 u64 dl_density; /* dl_runtime / dl_deadline */ 611 612 /* 613 * Actual scheduling parameters. Initialized with the values above, 614 * they are continuously updated during task execution. Note that 615 * the remaining runtime could be < 0 in case we are in overrun. 616 */ 617 s64 runtime; /* Remaining runtime for this instance */ 618 u64 deadline; /* Absolute deadline for this instance */ 619 unsigned int flags; /* Specifying the scheduler behaviour */ 620 621 /* 622 * Some bool flags: 623 * 624 * @dl_throttled tells if we exhausted the runtime. If so, the 625 * task has to wait for a replenishment to be performed at the 626 * next firing of dl_timer. 627 * 628 * @dl_yielded tells if task gave up the CPU before consuming 629 * all its available runtime during the last job. 630 * 631 * @dl_non_contending tells if the task is inactive while still 632 * contributing to the active utilization. In other words, it 633 * indicates if the inactive timer has been armed and its handler 634 * has not been executed yet. This flag is useful to avoid race 635 * conditions between the inactive timer handler and the wakeup 636 * code. 637 * 638 * @dl_overrun tells if the task asked to be informed about runtime 639 * overruns. 640 */ 641 unsigned int dl_throttled : 1; 642 unsigned int dl_yielded : 1; 643 unsigned int dl_non_contending : 1; 644 unsigned int dl_overrun : 1; 645 unsigned int dl_server : 1; 646 647 /* 648 * Bandwidth enforcement timer. Each -deadline task has its 649 * own bandwidth to be enforced, thus we need one timer per task. 650 */ 651 struct hrtimer dl_timer; 652 653 /* 654 * Inactive timer, responsible for decreasing the active utilization 655 * at the "0-lag time". When a -deadline task blocks, it contributes 656 * to GRUB's active utilization until the "0-lag time", hence a 657 * timer is needed to decrease the active utilization at the correct 658 * time. 659 */ 660 struct hrtimer inactive_timer; 661 662 /* 663 * Bits for DL-server functionality. Also see the comment near 664 * dl_server_update(). 665 * 666 * @rq the runqueue this server is for 667 * 668 * @server_has_tasks() returns true if @server_pick return a 669 * runnable task. 670 */ 671 struct rq *rq; 672 dl_server_has_tasks_f server_has_tasks; 673 dl_server_pick_f server_pick; 674 675 #ifdef CONFIG_RT_MUTEXES 676 /* 677 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 678 * pi_se points to the donor, otherwise points to the dl_se it belongs 679 * to (the original one/itself). 680 */ 681 struct sched_dl_entity *pi_se; 682 #endif 683 }; 684 685 #ifdef CONFIG_UCLAMP_TASK 686 /* Number of utilization clamp buckets (shorter alias) */ 687 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 688 689 /* 690 * Utilization clamp for a scheduling entity 691 * @value: clamp value "assigned" to a se 692 * @bucket_id: bucket index corresponding to the "assigned" value 693 * @active: the se is currently refcounted in a rq's bucket 694 * @user_defined: the requested clamp value comes from user-space 695 * 696 * The bucket_id is the index of the clamp bucket matching the clamp value 697 * which is pre-computed and stored to avoid expensive integer divisions from 698 * the fast path. 699 * 700 * The active bit is set whenever a task has got an "effective" value assigned, 701 * which can be different from the clamp value "requested" from user-space. 702 * This allows to know a task is refcounted in the rq's bucket corresponding 703 * to the "effective" bucket_id. 704 * 705 * The user_defined bit is set whenever a task has got a task-specific clamp 706 * value requested from userspace, i.e. the system defaults apply to this task 707 * just as a restriction. This allows to relax default clamps when a less 708 * restrictive task-specific value has been requested, thus allowing to 709 * implement a "nice" semantic. For example, a task running with a 20% 710 * default boost can still drop its own boosting to 0%. 711 */ 712 struct uclamp_se { 713 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 714 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 715 unsigned int active : 1; 716 unsigned int user_defined : 1; 717 }; 718 #endif /* CONFIG_UCLAMP_TASK */ 719 720 union rcu_special { 721 struct { 722 u8 blocked; 723 u8 need_qs; 724 u8 exp_hint; /* Hint for performance. */ 725 u8 need_mb; /* Readers need smp_mb(). */ 726 } b; /* Bits. */ 727 u32 s; /* Set of bits. */ 728 }; 729 730 enum perf_event_task_context { 731 perf_invalid_context = -1, 732 perf_hw_context = 0, 733 perf_sw_context, 734 perf_nr_task_contexts, 735 }; 736 737 struct wake_q_node { 738 struct wake_q_node *next; 739 }; 740 741 struct kmap_ctrl { 742 #ifdef CONFIG_KMAP_LOCAL 743 int idx; 744 pte_t pteval[KM_MAX_IDX]; 745 #endif 746 }; 747 748 struct task_struct { 749 #ifdef CONFIG_THREAD_INFO_IN_TASK 750 /* 751 * For reasons of header soup (see current_thread_info()), this 752 * must be the first element of task_struct. 753 */ 754 struct thread_info thread_info; 755 #endif 756 unsigned int __state; 757 758 /* saved state for "spinlock sleepers" */ 759 unsigned int saved_state; 760 761 /* 762 * This begins the randomizable portion of task_struct. Only 763 * scheduling-critical items should be added above here. 764 */ 765 randomized_struct_fields_start 766 767 void *stack; 768 refcount_t usage; 769 /* Per task flags (PF_*), defined further below: */ 770 unsigned int flags; 771 unsigned int ptrace; 772 773 #ifdef CONFIG_SMP 774 int on_cpu; 775 struct __call_single_node wake_entry; 776 unsigned int wakee_flips; 777 unsigned long wakee_flip_decay_ts; 778 struct task_struct *last_wakee; 779 780 /* 781 * recent_used_cpu is initially set as the last CPU used by a task 782 * that wakes affine another task. Waker/wakee relationships can 783 * push tasks around a CPU where each wakeup moves to the next one. 784 * Tracking a recently used CPU allows a quick search for a recently 785 * used CPU that may be idle. 786 */ 787 int recent_used_cpu; 788 int wake_cpu; 789 #endif 790 int on_rq; 791 792 int prio; 793 int static_prio; 794 int normal_prio; 795 unsigned int rt_priority; 796 797 struct sched_entity se; 798 struct sched_rt_entity rt; 799 struct sched_dl_entity dl; 800 struct sched_dl_entity *dl_server; 801 const struct sched_class *sched_class; 802 803 #ifdef CONFIG_SCHED_CORE 804 struct rb_node core_node; 805 unsigned long core_cookie; 806 unsigned int core_occupation; 807 #endif 808 809 #ifdef CONFIG_CGROUP_SCHED 810 struct task_group *sched_task_group; 811 #endif 812 813 #ifdef CONFIG_UCLAMP_TASK 814 /* 815 * Clamp values requested for a scheduling entity. 816 * Must be updated with task_rq_lock() held. 817 */ 818 struct uclamp_se uclamp_req[UCLAMP_CNT]; 819 /* 820 * Effective clamp values used for a scheduling entity. 821 * Must be updated with task_rq_lock() held. 822 */ 823 struct uclamp_se uclamp[UCLAMP_CNT]; 824 #endif 825 826 struct sched_statistics stats; 827 828 #ifdef CONFIG_PREEMPT_NOTIFIERS 829 /* List of struct preempt_notifier: */ 830 struct hlist_head preempt_notifiers; 831 #endif 832 833 #ifdef CONFIG_BLK_DEV_IO_TRACE 834 unsigned int btrace_seq; 835 #endif 836 837 unsigned int policy; 838 int nr_cpus_allowed; 839 const cpumask_t *cpus_ptr; 840 cpumask_t *user_cpus_ptr; 841 cpumask_t cpus_mask; 842 void *migration_pending; 843 #ifdef CONFIG_SMP 844 unsigned short migration_disabled; 845 #endif 846 unsigned short migration_flags; 847 848 #ifdef CONFIG_PREEMPT_RCU 849 int rcu_read_lock_nesting; 850 union rcu_special rcu_read_unlock_special; 851 struct list_head rcu_node_entry; 852 struct rcu_node *rcu_blocked_node; 853 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 854 855 #ifdef CONFIG_TASKS_RCU 856 unsigned long rcu_tasks_nvcsw; 857 u8 rcu_tasks_holdout; 858 u8 rcu_tasks_idx; 859 int rcu_tasks_idle_cpu; 860 struct list_head rcu_tasks_holdout_list; 861 int rcu_tasks_exit_cpu; 862 struct list_head rcu_tasks_exit_list; 863 #endif /* #ifdef CONFIG_TASKS_RCU */ 864 865 #ifdef CONFIG_TASKS_TRACE_RCU 866 int trc_reader_nesting; 867 int trc_ipi_to_cpu; 868 union rcu_special trc_reader_special; 869 struct list_head trc_holdout_list; 870 struct list_head trc_blkd_node; 871 int trc_blkd_cpu; 872 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 873 874 struct sched_info sched_info; 875 876 struct list_head tasks; 877 #ifdef CONFIG_SMP 878 struct plist_node pushable_tasks; 879 struct rb_node pushable_dl_tasks; 880 #endif 881 882 struct mm_struct *mm; 883 struct mm_struct *active_mm; 884 struct address_space *faults_disabled_mapping; 885 886 int exit_state; 887 int exit_code; 888 int exit_signal; 889 /* The signal sent when the parent dies: */ 890 int pdeath_signal; 891 /* JOBCTL_*, siglock protected: */ 892 unsigned long jobctl; 893 894 /* Used for emulating ABI behavior of previous Linux versions: */ 895 unsigned int personality; 896 897 /* Scheduler bits, serialized by scheduler locks: */ 898 unsigned sched_reset_on_fork:1; 899 unsigned sched_contributes_to_load:1; 900 unsigned sched_migrated:1; 901 902 /* Force alignment to the next boundary: */ 903 unsigned :0; 904 905 /* Unserialized, strictly 'current' */ 906 907 /* 908 * This field must not be in the scheduler word above due to wakelist 909 * queueing no longer being serialized by p->on_cpu. However: 910 * 911 * p->XXX = X; ttwu() 912 * schedule() if (p->on_rq && ..) // false 913 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 914 * deactivate_task() ttwu_queue_wakelist()) 915 * p->on_rq = 0; p->sched_remote_wakeup = Y; 916 * 917 * guarantees all stores of 'current' are visible before 918 * ->sched_remote_wakeup gets used, so it can be in this word. 919 */ 920 unsigned sched_remote_wakeup:1; 921 #ifdef CONFIG_RT_MUTEXES 922 unsigned sched_rt_mutex:1; 923 #endif 924 925 /* Bit to tell TOMOYO we're in execve(): */ 926 unsigned in_execve:1; 927 unsigned in_iowait:1; 928 #ifndef TIF_RESTORE_SIGMASK 929 unsigned restore_sigmask:1; 930 #endif 931 #ifdef CONFIG_MEMCG 932 unsigned in_user_fault:1; 933 #endif 934 #ifdef CONFIG_LRU_GEN 935 /* whether the LRU algorithm may apply to this access */ 936 unsigned in_lru_fault:1; 937 #endif 938 #ifdef CONFIG_COMPAT_BRK 939 unsigned brk_randomized:1; 940 #endif 941 #ifdef CONFIG_CGROUPS 942 /* disallow userland-initiated cgroup migration */ 943 unsigned no_cgroup_migration:1; 944 /* task is frozen/stopped (used by the cgroup freezer) */ 945 unsigned frozen:1; 946 #endif 947 #ifdef CONFIG_BLK_CGROUP 948 unsigned use_memdelay:1; 949 #endif 950 #ifdef CONFIG_PSI 951 /* Stalled due to lack of memory */ 952 unsigned in_memstall:1; 953 #endif 954 #ifdef CONFIG_PAGE_OWNER 955 /* Used by page_owner=on to detect recursion in page tracking. */ 956 unsigned in_page_owner:1; 957 #endif 958 #ifdef CONFIG_EVENTFD 959 /* Recursion prevention for eventfd_signal() */ 960 unsigned in_eventfd:1; 961 #endif 962 #ifdef CONFIG_ARCH_HAS_CPU_PASID 963 unsigned pasid_activated:1; 964 #endif 965 #ifdef CONFIG_CPU_SUP_INTEL 966 unsigned reported_split_lock:1; 967 #endif 968 #ifdef CONFIG_TASK_DELAY_ACCT 969 /* delay due to memory thrashing */ 970 unsigned in_thrashing:1; 971 #endif 972 973 unsigned long atomic_flags; /* Flags requiring atomic access. */ 974 975 struct restart_block restart_block; 976 977 pid_t pid; 978 pid_t tgid; 979 980 #ifdef CONFIG_STACKPROTECTOR 981 /* Canary value for the -fstack-protector GCC feature: */ 982 unsigned long stack_canary; 983 #endif 984 /* 985 * Pointers to the (original) parent process, youngest child, younger sibling, 986 * older sibling, respectively. (p->father can be replaced with 987 * p->real_parent->pid) 988 */ 989 990 /* Real parent process: */ 991 struct task_struct __rcu *real_parent; 992 993 /* Recipient of SIGCHLD, wait4() reports: */ 994 struct task_struct __rcu *parent; 995 996 /* 997 * Children/sibling form the list of natural children: 998 */ 999 struct list_head children; 1000 struct list_head sibling; 1001 struct task_struct *group_leader; 1002 1003 /* 1004 * 'ptraced' is the list of tasks this task is using ptrace() on. 1005 * 1006 * This includes both natural children and PTRACE_ATTACH targets. 1007 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 1008 */ 1009 struct list_head ptraced; 1010 struct list_head ptrace_entry; 1011 1012 /* PID/PID hash table linkage. */ 1013 struct pid *thread_pid; 1014 struct hlist_node pid_links[PIDTYPE_MAX]; 1015 struct list_head thread_node; 1016 1017 struct completion *vfork_done; 1018 1019 /* CLONE_CHILD_SETTID: */ 1020 int __user *set_child_tid; 1021 1022 /* CLONE_CHILD_CLEARTID: */ 1023 int __user *clear_child_tid; 1024 1025 /* PF_KTHREAD | PF_IO_WORKER */ 1026 void *worker_private; 1027 1028 u64 utime; 1029 u64 stime; 1030 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1031 u64 utimescaled; 1032 u64 stimescaled; 1033 #endif 1034 u64 gtime; 1035 struct prev_cputime prev_cputime; 1036 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1037 struct vtime vtime; 1038 #endif 1039 1040 #ifdef CONFIG_NO_HZ_FULL 1041 atomic_t tick_dep_mask; 1042 #endif 1043 /* Context switch counts: */ 1044 unsigned long nvcsw; 1045 unsigned long nivcsw; 1046 1047 /* Monotonic time in nsecs: */ 1048 u64 start_time; 1049 1050 /* Boot based time in nsecs: */ 1051 u64 start_boottime; 1052 1053 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1054 unsigned long min_flt; 1055 unsigned long maj_flt; 1056 1057 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1058 struct posix_cputimers posix_cputimers; 1059 1060 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1061 struct posix_cputimers_work posix_cputimers_work; 1062 #endif 1063 1064 /* Process credentials: */ 1065 1066 /* Tracer's credentials at attach: */ 1067 const struct cred __rcu *ptracer_cred; 1068 1069 /* Objective and real subjective task credentials (COW): */ 1070 const struct cred __rcu *real_cred; 1071 1072 /* Effective (overridable) subjective task credentials (COW): */ 1073 const struct cred __rcu *cred; 1074 1075 #ifdef CONFIG_KEYS 1076 /* Cached requested key. */ 1077 struct key *cached_requested_key; 1078 #endif 1079 1080 /* 1081 * executable name, excluding path. 1082 * 1083 * - normally initialized setup_new_exec() 1084 * - access it with [gs]et_task_comm() 1085 * - lock it with task_lock() 1086 */ 1087 char comm[TASK_COMM_LEN]; 1088 1089 struct nameidata *nameidata; 1090 1091 #ifdef CONFIG_SYSVIPC 1092 struct sysv_sem sysvsem; 1093 struct sysv_shm sysvshm; 1094 #endif 1095 #ifdef CONFIG_DETECT_HUNG_TASK 1096 unsigned long last_switch_count; 1097 unsigned long last_switch_time; 1098 #endif 1099 /* Filesystem information: */ 1100 struct fs_struct *fs; 1101 1102 /* Open file information: */ 1103 struct files_struct *files; 1104 1105 #ifdef CONFIG_IO_URING 1106 struct io_uring_task *io_uring; 1107 #endif 1108 1109 /* Namespaces: */ 1110 struct nsproxy *nsproxy; 1111 1112 /* Signal handlers: */ 1113 struct signal_struct *signal; 1114 struct sighand_struct __rcu *sighand; 1115 sigset_t blocked; 1116 sigset_t real_blocked; 1117 /* Restored if set_restore_sigmask() was used: */ 1118 sigset_t saved_sigmask; 1119 struct sigpending pending; 1120 unsigned long sas_ss_sp; 1121 size_t sas_ss_size; 1122 unsigned int sas_ss_flags; 1123 1124 struct callback_head *task_works; 1125 1126 #ifdef CONFIG_AUDIT 1127 #ifdef CONFIG_AUDITSYSCALL 1128 struct audit_context *audit_context; 1129 #endif 1130 kuid_t loginuid; 1131 unsigned int sessionid; 1132 #endif 1133 struct seccomp seccomp; 1134 struct syscall_user_dispatch syscall_dispatch; 1135 1136 /* Thread group tracking: */ 1137 u64 parent_exec_id; 1138 u64 self_exec_id; 1139 1140 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1141 spinlock_t alloc_lock; 1142 1143 /* Protection of the PI data structures: */ 1144 raw_spinlock_t pi_lock; 1145 1146 struct wake_q_node wake_q; 1147 1148 #ifdef CONFIG_RT_MUTEXES 1149 /* PI waiters blocked on a rt_mutex held by this task: */ 1150 struct rb_root_cached pi_waiters; 1151 /* Updated under owner's pi_lock and rq lock */ 1152 struct task_struct *pi_top_task; 1153 /* Deadlock detection and priority inheritance handling: */ 1154 struct rt_mutex_waiter *pi_blocked_on; 1155 #endif 1156 1157 #ifdef CONFIG_DEBUG_MUTEXES 1158 /* Mutex deadlock detection: */ 1159 struct mutex_waiter *blocked_on; 1160 #endif 1161 1162 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1163 int non_block_count; 1164 #endif 1165 1166 #ifdef CONFIG_TRACE_IRQFLAGS 1167 struct irqtrace_events irqtrace; 1168 unsigned int hardirq_threaded; 1169 u64 hardirq_chain_key; 1170 int softirqs_enabled; 1171 int softirq_context; 1172 int irq_config; 1173 #endif 1174 #ifdef CONFIG_PREEMPT_RT 1175 int softirq_disable_cnt; 1176 #endif 1177 1178 #ifdef CONFIG_LOCKDEP 1179 # define MAX_LOCK_DEPTH 48UL 1180 u64 curr_chain_key; 1181 int lockdep_depth; 1182 unsigned int lockdep_recursion; 1183 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1184 #endif 1185 1186 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1187 unsigned int in_ubsan; 1188 #endif 1189 1190 /* Journalling filesystem info: */ 1191 void *journal_info; 1192 1193 /* Stacked block device info: */ 1194 struct bio_list *bio_list; 1195 1196 /* Stack plugging: */ 1197 struct blk_plug *plug; 1198 1199 /* VM state: */ 1200 struct reclaim_state *reclaim_state; 1201 1202 struct io_context *io_context; 1203 1204 #ifdef CONFIG_COMPACTION 1205 struct capture_control *capture_control; 1206 #endif 1207 /* Ptrace state: */ 1208 unsigned long ptrace_message; 1209 kernel_siginfo_t *last_siginfo; 1210 1211 struct task_io_accounting ioac; 1212 #ifdef CONFIG_PSI 1213 /* Pressure stall state */ 1214 unsigned int psi_flags; 1215 #endif 1216 #ifdef CONFIG_TASK_XACCT 1217 /* Accumulated RSS usage: */ 1218 u64 acct_rss_mem1; 1219 /* Accumulated virtual memory usage: */ 1220 u64 acct_vm_mem1; 1221 /* stime + utime since last update: */ 1222 u64 acct_timexpd; 1223 #endif 1224 #ifdef CONFIG_CPUSETS 1225 /* Protected by ->alloc_lock: */ 1226 nodemask_t mems_allowed; 1227 /* Sequence number to catch updates: */ 1228 seqcount_spinlock_t mems_allowed_seq; 1229 int cpuset_mem_spread_rotor; 1230 int cpuset_slab_spread_rotor; 1231 #endif 1232 #ifdef CONFIG_CGROUPS 1233 /* Control Group info protected by css_set_lock: */ 1234 struct css_set __rcu *cgroups; 1235 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1236 struct list_head cg_list; 1237 #endif 1238 #ifdef CONFIG_X86_CPU_RESCTRL 1239 u32 closid; 1240 u32 rmid; 1241 #endif 1242 #ifdef CONFIG_FUTEX 1243 struct robust_list_head __user *robust_list; 1244 #ifdef CONFIG_COMPAT 1245 struct compat_robust_list_head __user *compat_robust_list; 1246 #endif 1247 struct list_head pi_state_list; 1248 struct futex_pi_state *pi_state_cache; 1249 struct mutex futex_exit_mutex; 1250 unsigned int futex_state; 1251 #endif 1252 #ifdef CONFIG_PERF_EVENTS 1253 struct perf_event_context *perf_event_ctxp; 1254 struct mutex perf_event_mutex; 1255 struct list_head perf_event_list; 1256 #endif 1257 #ifdef CONFIG_DEBUG_PREEMPT 1258 unsigned long preempt_disable_ip; 1259 #endif 1260 #ifdef CONFIG_NUMA 1261 /* Protected by alloc_lock: */ 1262 struct mempolicy *mempolicy; 1263 short il_prev; 1264 short pref_node_fork; 1265 #endif 1266 #ifdef CONFIG_NUMA_BALANCING 1267 int numa_scan_seq; 1268 unsigned int numa_scan_period; 1269 unsigned int numa_scan_period_max; 1270 int numa_preferred_nid; 1271 unsigned long numa_migrate_retry; 1272 /* Migration stamp: */ 1273 u64 node_stamp; 1274 u64 last_task_numa_placement; 1275 u64 last_sum_exec_runtime; 1276 struct callback_head numa_work; 1277 1278 /* 1279 * This pointer is only modified for current in syscall and 1280 * pagefault context (and for tasks being destroyed), so it can be read 1281 * from any of the following contexts: 1282 * - RCU read-side critical section 1283 * - current->numa_group from everywhere 1284 * - task's runqueue locked, task not running 1285 */ 1286 struct numa_group __rcu *numa_group; 1287 1288 /* 1289 * numa_faults is an array split into four regions: 1290 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1291 * in this precise order. 1292 * 1293 * faults_memory: Exponential decaying average of faults on a per-node 1294 * basis. Scheduling placement decisions are made based on these 1295 * counts. The values remain static for the duration of a PTE scan. 1296 * faults_cpu: Track the nodes the process was running on when a NUMA 1297 * hinting fault was incurred. 1298 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1299 * during the current scan window. When the scan completes, the counts 1300 * in faults_memory and faults_cpu decay and these values are copied. 1301 */ 1302 unsigned long *numa_faults; 1303 unsigned long total_numa_faults; 1304 1305 /* 1306 * numa_faults_locality tracks if faults recorded during the last 1307 * scan window were remote/local or failed to migrate. The task scan 1308 * period is adapted based on the locality of the faults with different 1309 * weights depending on whether they were shared or private faults 1310 */ 1311 unsigned long numa_faults_locality[3]; 1312 1313 unsigned long numa_pages_migrated; 1314 #endif /* CONFIG_NUMA_BALANCING */ 1315 1316 #ifdef CONFIG_RSEQ 1317 struct rseq __user *rseq; 1318 u32 rseq_len; 1319 u32 rseq_sig; 1320 /* 1321 * RmW on rseq_event_mask must be performed atomically 1322 * with respect to preemption. 1323 */ 1324 unsigned long rseq_event_mask; 1325 #endif 1326 1327 #ifdef CONFIG_SCHED_MM_CID 1328 int mm_cid; /* Current cid in mm */ 1329 int last_mm_cid; /* Most recent cid in mm */ 1330 int migrate_from_cpu; 1331 int mm_cid_active; /* Whether cid bitmap is active */ 1332 struct callback_head cid_work; 1333 #endif 1334 1335 struct tlbflush_unmap_batch tlb_ubc; 1336 1337 /* Cache last used pipe for splice(): */ 1338 struct pipe_inode_info *splice_pipe; 1339 1340 struct page_frag task_frag; 1341 1342 #ifdef CONFIG_TASK_DELAY_ACCT 1343 struct task_delay_info *delays; 1344 #endif 1345 1346 #ifdef CONFIG_FAULT_INJECTION 1347 int make_it_fail; 1348 unsigned int fail_nth; 1349 #endif 1350 /* 1351 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1352 * balance_dirty_pages() for a dirty throttling pause: 1353 */ 1354 int nr_dirtied; 1355 int nr_dirtied_pause; 1356 /* Start of a write-and-pause period: */ 1357 unsigned long dirty_paused_when; 1358 1359 #ifdef CONFIG_LATENCYTOP 1360 int latency_record_count; 1361 struct latency_record latency_record[LT_SAVECOUNT]; 1362 #endif 1363 /* 1364 * Time slack values; these are used to round up poll() and 1365 * select() etc timeout values. These are in nanoseconds. 1366 */ 1367 u64 timer_slack_ns; 1368 u64 default_timer_slack_ns; 1369 1370 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1371 unsigned int kasan_depth; 1372 #endif 1373 1374 #ifdef CONFIG_KCSAN 1375 struct kcsan_ctx kcsan_ctx; 1376 #ifdef CONFIG_TRACE_IRQFLAGS 1377 struct irqtrace_events kcsan_save_irqtrace; 1378 #endif 1379 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1380 int kcsan_stack_depth; 1381 #endif 1382 #endif 1383 1384 #ifdef CONFIG_KMSAN 1385 struct kmsan_ctx kmsan_ctx; 1386 #endif 1387 1388 #if IS_ENABLED(CONFIG_KUNIT) 1389 struct kunit *kunit_test; 1390 #endif 1391 1392 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1393 /* Index of current stored address in ret_stack: */ 1394 int curr_ret_stack; 1395 int curr_ret_depth; 1396 1397 /* Stack of return addresses for return function tracing: */ 1398 struct ftrace_ret_stack *ret_stack; 1399 1400 /* Timestamp for last schedule: */ 1401 unsigned long long ftrace_timestamp; 1402 1403 /* 1404 * Number of functions that haven't been traced 1405 * because of depth overrun: 1406 */ 1407 atomic_t trace_overrun; 1408 1409 /* Pause tracing: */ 1410 atomic_t tracing_graph_pause; 1411 #endif 1412 1413 #ifdef CONFIG_TRACING 1414 /* Bitmask and counter of trace recursion: */ 1415 unsigned long trace_recursion; 1416 #endif /* CONFIG_TRACING */ 1417 1418 #ifdef CONFIG_KCOV 1419 /* See kernel/kcov.c for more details. */ 1420 1421 /* Coverage collection mode enabled for this task (0 if disabled): */ 1422 unsigned int kcov_mode; 1423 1424 /* Size of the kcov_area: */ 1425 unsigned int kcov_size; 1426 1427 /* Buffer for coverage collection: */ 1428 void *kcov_area; 1429 1430 /* KCOV descriptor wired with this task or NULL: */ 1431 struct kcov *kcov; 1432 1433 /* KCOV common handle for remote coverage collection: */ 1434 u64 kcov_handle; 1435 1436 /* KCOV sequence number: */ 1437 int kcov_sequence; 1438 1439 /* Collect coverage from softirq context: */ 1440 unsigned int kcov_softirq; 1441 #endif 1442 1443 #ifdef CONFIG_MEMCG 1444 struct mem_cgroup *memcg_in_oom; 1445 gfp_t memcg_oom_gfp_mask; 1446 int memcg_oom_order; 1447 1448 /* Number of pages to reclaim on returning to userland: */ 1449 unsigned int memcg_nr_pages_over_high; 1450 1451 /* Used by memcontrol for targeted memcg charge: */ 1452 struct mem_cgroup *active_memcg; 1453 #endif 1454 1455 #ifdef CONFIG_MEMCG_KMEM 1456 struct obj_cgroup *objcg; 1457 #endif 1458 1459 #ifdef CONFIG_BLK_CGROUP 1460 struct gendisk *throttle_disk; 1461 #endif 1462 1463 #ifdef CONFIG_UPROBES 1464 struct uprobe_task *utask; 1465 #endif 1466 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1467 unsigned int sequential_io; 1468 unsigned int sequential_io_avg; 1469 #endif 1470 struct kmap_ctrl kmap_ctrl; 1471 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1472 unsigned long task_state_change; 1473 # ifdef CONFIG_PREEMPT_RT 1474 unsigned long saved_state_change; 1475 # endif 1476 #endif 1477 struct rcu_head rcu; 1478 refcount_t rcu_users; 1479 int pagefault_disabled; 1480 #ifdef CONFIG_MMU 1481 struct task_struct *oom_reaper_list; 1482 struct timer_list oom_reaper_timer; 1483 #endif 1484 #ifdef CONFIG_VMAP_STACK 1485 struct vm_struct *stack_vm_area; 1486 #endif 1487 #ifdef CONFIG_THREAD_INFO_IN_TASK 1488 /* A live task holds one reference: */ 1489 refcount_t stack_refcount; 1490 #endif 1491 #ifdef CONFIG_LIVEPATCH 1492 int patch_state; 1493 #endif 1494 #ifdef CONFIG_SECURITY 1495 /* Used by LSM modules for access restriction: */ 1496 void *security; 1497 #endif 1498 #ifdef CONFIG_BPF_SYSCALL 1499 /* Used by BPF task local storage */ 1500 struct bpf_local_storage __rcu *bpf_storage; 1501 /* Used for BPF run context */ 1502 struct bpf_run_ctx *bpf_ctx; 1503 #endif 1504 1505 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1506 unsigned long lowest_stack; 1507 unsigned long prev_lowest_stack; 1508 #endif 1509 1510 #ifdef CONFIG_X86_MCE 1511 void __user *mce_vaddr; 1512 __u64 mce_kflags; 1513 u64 mce_addr; 1514 __u64 mce_ripv : 1, 1515 mce_whole_page : 1, 1516 __mce_reserved : 62; 1517 struct callback_head mce_kill_me; 1518 int mce_count; 1519 #endif 1520 1521 #ifdef CONFIG_KRETPROBES 1522 struct llist_head kretprobe_instances; 1523 #endif 1524 #ifdef CONFIG_RETHOOK 1525 struct llist_head rethooks; 1526 #endif 1527 1528 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1529 /* 1530 * If L1D flush is supported on mm context switch 1531 * then we use this callback head to queue kill work 1532 * to kill tasks that are not running on SMT disabled 1533 * cores 1534 */ 1535 struct callback_head l1d_flush_kill; 1536 #endif 1537 1538 #ifdef CONFIG_RV 1539 /* 1540 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1541 * If we find justification for more monitors, we can think 1542 * about adding more or developing a dynamic method. So far, 1543 * none of these are justified. 1544 */ 1545 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1546 #endif 1547 1548 #ifdef CONFIG_USER_EVENTS 1549 struct user_event_mm *user_event_mm; 1550 #endif 1551 1552 /* 1553 * New fields for task_struct should be added above here, so that 1554 * they are included in the randomized portion of task_struct. 1555 */ 1556 randomized_struct_fields_end 1557 1558 /* CPU-specific state of this task: */ 1559 struct thread_struct thread; 1560 1561 /* 1562 * WARNING: on x86, 'thread_struct' contains a variable-sized 1563 * structure. It *MUST* be at the end of 'task_struct'. 1564 * 1565 * Do not put anything below here! 1566 */ 1567 }; 1568 1569 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1570 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1571 1572 static inline unsigned int __task_state_index(unsigned int tsk_state, 1573 unsigned int tsk_exit_state) 1574 { 1575 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1576 1577 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1578 1579 if ((tsk_state & TASK_IDLE) == TASK_IDLE) 1580 state = TASK_REPORT_IDLE; 1581 1582 /* 1583 * We're lying here, but rather than expose a completely new task state 1584 * to userspace, we can make this appear as if the task has gone through 1585 * a regular rt_mutex_lock() call. 1586 */ 1587 if (tsk_state & TASK_RTLOCK_WAIT) 1588 state = TASK_UNINTERRUPTIBLE; 1589 1590 return fls(state); 1591 } 1592 1593 static inline unsigned int task_state_index(struct task_struct *tsk) 1594 { 1595 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1596 } 1597 1598 static inline char task_index_to_char(unsigned int state) 1599 { 1600 static const char state_char[] = "RSDTtXZPI"; 1601 1602 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1603 1604 return state_char[state]; 1605 } 1606 1607 static inline char task_state_to_char(struct task_struct *tsk) 1608 { 1609 return task_index_to_char(task_state_index(tsk)); 1610 } 1611 1612 extern struct pid *cad_pid; 1613 1614 /* 1615 * Per process flags 1616 */ 1617 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1618 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1619 #define PF_EXITING 0x00000004 /* Getting shut down */ 1620 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1621 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1622 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1623 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1624 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1625 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1626 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1627 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1628 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1629 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1630 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1631 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1632 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1633 #define PF__HOLE__00010000 0x00010000 1634 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1635 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1636 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1637 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1638 * I am cleaning dirty pages from some other bdi. */ 1639 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1640 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1641 #define PF__HOLE__00800000 0x00800000 1642 #define PF__HOLE__01000000 0x01000000 1643 #define PF__HOLE__02000000 0x02000000 1644 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1645 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1646 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1647 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */ 1648 #define PF__HOLE__40000000 0x40000000 1649 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1650 1651 /* 1652 * Only the _current_ task can read/write to tsk->flags, but other 1653 * tasks can access tsk->flags in readonly mode for example 1654 * with tsk_used_math (like during threaded core dumping). 1655 * There is however an exception to this rule during ptrace 1656 * or during fork: the ptracer task is allowed to write to the 1657 * child->flags of its traced child (same goes for fork, the parent 1658 * can write to the child->flags), because we're guaranteed the 1659 * child is not running and in turn not changing child->flags 1660 * at the same time the parent does it. 1661 */ 1662 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1663 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1664 #define clear_used_math() clear_stopped_child_used_math(current) 1665 #define set_used_math() set_stopped_child_used_math(current) 1666 1667 #define conditional_stopped_child_used_math(condition, child) \ 1668 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1669 1670 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1671 1672 #define copy_to_stopped_child_used_math(child) \ 1673 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1674 1675 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1676 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1677 #define used_math() tsk_used_math(current) 1678 1679 static __always_inline bool is_percpu_thread(void) 1680 { 1681 #ifdef CONFIG_SMP 1682 return (current->flags & PF_NO_SETAFFINITY) && 1683 (current->nr_cpus_allowed == 1); 1684 #else 1685 return true; 1686 #endif 1687 } 1688 1689 /* Per-process atomic flags. */ 1690 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1691 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1692 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1693 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1694 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1695 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1696 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1697 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1698 1699 #define TASK_PFA_TEST(name, func) \ 1700 static inline bool task_##func(struct task_struct *p) \ 1701 { return test_bit(PFA_##name, &p->atomic_flags); } 1702 1703 #define TASK_PFA_SET(name, func) \ 1704 static inline void task_set_##func(struct task_struct *p) \ 1705 { set_bit(PFA_##name, &p->atomic_flags); } 1706 1707 #define TASK_PFA_CLEAR(name, func) \ 1708 static inline void task_clear_##func(struct task_struct *p) \ 1709 { clear_bit(PFA_##name, &p->atomic_flags); } 1710 1711 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1712 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1713 1714 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1715 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1716 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1717 1718 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1719 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1720 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1721 1722 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1723 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1724 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1725 1726 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1727 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1728 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1729 1730 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1731 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1732 1733 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1734 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1735 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1736 1737 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1738 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1739 1740 static inline void 1741 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1742 { 1743 current->flags &= ~flags; 1744 current->flags |= orig_flags & flags; 1745 } 1746 1747 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1748 extern int task_can_attach(struct task_struct *p); 1749 extern int dl_bw_alloc(int cpu, u64 dl_bw); 1750 extern void dl_bw_free(int cpu, u64 dl_bw); 1751 #ifdef CONFIG_SMP 1752 1753 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */ 1754 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1755 1756 /** 1757 * set_cpus_allowed_ptr - set CPU affinity mask of a task 1758 * @p: the task 1759 * @new_mask: CPU affinity mask 1760 * 1761 * Return: zero if successful, or a negative error code 1762 */ 1763 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1764 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1765 extern void release_user_cpus_ptr(struct task_struct *p); 1766 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1767 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1768 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1769 #else 1770 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1771 { 1772 } 1773 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1774 { 1775 if (!cpumask_test_cpu(0, new_mask)) 1776 return -EINVAL; 1777 return 0; 1778 } 1779 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1780 { 1781 if (src->user_cpus_ptr) 1782 return -EINVAL; 1783 return 0; 1784 } 1785 static inline void release_user_cpus_ptr(struct task_struct *p) 1786 { 1787 WARN_ON(p->user_cpus_ptr); 1788 } 1789 1790 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1791 { 1792 return 0; 1793 } 1794 #endif 1795 1796 extern int yield_to(struct task_struct *p, bool preempt); 1797 extern void set_user_nice(struct task_struct *p, long nice); 1798 extern int task_prio(const struct task_struct *p); 1799 1800 /** 1801 * task_nice - return the nice value of a given task. 1802 * @p: the task in question. 1803 * 1804 * Return: The nice value [ -20 ... 0 ... 19 ]. 1805 */ 1806 static inline int task_nice(const struct task_struct *p) 1807 { 1808 return PRIO_TO_NICE((p)->static_prio); 1809 } 1810 1811 extern int can_nice(const struct task_struct *p, const int nice); 1812 extern int task_curr(const struct task_struct *p); 1813 extern int idle_cpu(int cpu); 1814 extern int available_idle_cpu(int cpu); 1815 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1816 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1817 extern void sched_set_fifo(struct task_struct *p); 1818 extern void sched_set_fifo_low(struct task_struct *p); 1819 extern void sched_set_normal(struct task_struct *p, int nice); 1820 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1821 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1822 extern struct task_struct *idle_task(int cpu); 1823 1824 /** 1825 * is_idle_task - is the specified task an idle task? 1826 * @p: the task in question. 1827 * 1828 * Return: 1 if @p is an idle task. 0 otherwise. 1829 */ 1830 static __always_inline bool is_idle_task(const struct task_struct *p) 1831 { 1832 return !!(p->flags & PF_IDLE); 1833 } 1834 1835 extern struct task_struct *curr_task(int cpu); 1836 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1837 1838 void yield(void); 1839 1840 union thread_union { 1841 struct task_struct task; 1842 #ifndef CONFIG_THREAD_INFO_IN_TASK 1843 struct thread_info thread_info; 1844 #endif 1845 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1846 }; 1847 1848 #ifndef CONFIG_THREAD_INFO_IN_TASK 1849 extern struct thread_info init_thread_info; 1850 #endif 1851 1852 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1853 1854 #ifdef CONFIG_THREAD_INFO_IN_TASK 1855 # define task_thread_info(task) (&(task)->thread_info) 1856 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1857 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1858 #endif 1859 1860 /* 1861 * find a task by one of its numerical ids 1862 * 1863 * find_task_by_pid_ns(): 1864 * finds a task by its pid in the specified namespace 1865 * find_task_by_vpid(): 1866 * finds a task by its virtual pid 1867 * 1868 * see also find_vpid() etc in include/linux/pid.h 1869 */ 1870 1871 extern struct task_struct *find_task_by_vpid(pid_t nr); 1872 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1873 1874 /* 1875 * find a task by its virtual pid and get the task struct 1876 */ 1877 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1878 1879 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1880 extern int wake_up_process(struct task_struct *tsk); 1881 extern void wake_up_new_task(struct task_struct *tsk); 1882 1883 #ifdef CONFIG_SMP 1884 extern void kick_process(struct task_struct *tsk); 1885 #else 1886 static inline void kick_process(struct task_struct *tsk) { } 1887 #endif 1888 1889 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1890 1891 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1892 { 1893 __set_task_comm(tsk, from, false); 1894 } 1895 1896 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1897 #define get_task_comm(buf, tsk) ({ \ 1898 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1899 __get_task_comm(buf, sizeof(buf), tsk); \ 1900 }) 1901 1902 #ifdef CONFIG_SMP 1903 static __always_inline void scheduler_ipi(void) 1904 { 1905 /* 1906 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1907 * TIF_NEED_RESCHED remotely (for the first time) will also send 1908 * this IPI. 1909 */ 1910 preempt_fold_need_resched(); 1911 } 1912 #else 1913 static inline void scheduler_ipi(void) { } 1914 #endif 1915 1916 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1917 1918 /* 1919 * Set thread flags in other task's structures. 1920 * See asm/thread_info.h for TIF_xxxx flags available: 1921 */ 1922 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1923 { 1924 set_ti_thread_flag(task_thread_info(tsk), flag); 1925 } 1926 1927 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1928 { 1929 clear_ti_thread_flag(task_thread_info(tsk), flag); 1930 } 1931 1932 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 1933 bool value) 1934 { 1935 update_ti_thread_flag(task_thread_info(tsk), flag, value); 1936 } 1937 1938 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1939 { 1940 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1941 } 1942 1943 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1944 { 1945 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1946 } 1947 1948 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1949 { 1950 return test_ti_thread_flag(task_thread_info(tsk), flag); 1951 } 1952 1953 static inline void set_tsk_need_resched(struct task_struct *tsk) 1954 { 1955 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1956 } 1957 1958 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1959 { 1960 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1961 } 1962 1963 static inline int test_tsk_need_resched(struct task_struct *tsk) 1964 { 1965 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 1966 } 1967 1968 /* 1969 * cond_resched() and cond_resched_lock(): latency reduction via 1970 * explicit rescheduling in places that are safe. The return 1971 * value indicates whether a reschedule was done in fact. 1972 * cond_resched_lock() will drop the spinlock before scheduling, 1973 */ 1974 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 1975 extern int __cond_resched(void); 1976 1977 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 1978 1979 void sched_dynamic_klp_enable(void); 1980 void sched_dynamic_klp_disable(void); 1981 1982 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 1983 1984 static __always_inline int _cond_resched(void) 1985 { 1986 return static_call_mod(cond_resched)(); 1987 } 1988 1989 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 1990 1991 extern int dynamic_cond_resched(void); 1992 1993 static __always_inline int _cond_resched(void) 1994 { 1995 return dynamic_cond_resched(); 1996 } 1997 1998 #else /* !CONFIG_PREEMPTION */ 1999 2000 static inline int _cond_resched(void) 2001 { 2002 klp_sched_try_switch(); 2003 return __cond_resched(); 2004 } 2005 2006 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2007 2008 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2009 2010 static inline int _cond_resched(void) 2011 { 2012 klp_sched_try_switch(); 2013 return 0; 2014 } 2015 2016 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2017 2018 #define cond_resched() ({ \ 2019 __might_resched(__FILE__, __LINE__, 0); \ 2020 _cond_resched(); \ 2021 }) 2022 2023 extern int __cond_resched_lock(spinlock_t *lock); 2024 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2025 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2026 2027 #define MIGHT_RESCHED_RCU_SHIFT 8 2028 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2029 2030 #ifndef CONFIG_PREEMPT_RT 2031 /* 2032 * Non RT kernels have an elevated preempt count due to the held lock, 2033 * but are not allowed to be inside a RCU read side critical section 2034 */ 2035 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2036 #else 2037 /* 2038 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2039 * cond_resched*lock() has to take that into account because it checks for 2040 * preempt_count() and rcu_preempt_depth(). 2041 */ 2042 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2043 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2044 #endif 2045 2046 #define cond_resched_lock(lock) ({ \ 2047 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2048 __cond_resched_lock(lock); \ 2049 }) 2050 2051 #define cond_resched_rwlock_read(lock) ({ \ 2052 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2053 __cond_resched_rwlock_read(lock); \ 2054 }) 2055 2056 #define cond_resched_rwlock_write(lock) ({ \ 2057 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2058 __cond_resched_rwlock_write(lock); \ 2059 }) 2060 2061 #ifdef CONFIG_PREEMPT_DYNAMIC 2062 2063 extern bool preempt_model_none(void); 2064 extern bool preempt_model_voluntary(void); 2065 extern bool preempt_model_full(void); 2066 2067 #else 2068 2069 static inline bool preempt_model_none(void) 2070 { 2071 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2072 } 2073 static inline bool preempt_model_voluntary(void) 2074 { 2075 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2076 } 2077 static inline bool preempt_model_full(void) 2078 { 2079 return IS_ENABLED(CONFIG_PREEMPT); 2080 } 2081 2082 #endif 2083 2084 static inline bool preempt_model_rt(void) 2085 { 2086 return IS_ENABLED(CONFIG_PREEMPT_RT); 2087 } 2088 2089 /* 2090 * Does the preemption model allow non-cooperative preemption? 2091 * 2092 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2093 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2094 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2095 * PREEMPT_NONE model. 2096 */ 2097 static inline bool preempt_model_preemptible(void) 2098 { 2099 return preempt_model_full() || preempt_model_rt(); 2100 } 2101 2102 static __always_inline bool need_resched(void) 2103 { 2104 return unlikely(tif_need_resched()); 2105 } 2106 2107 /* 2108 * Wrappers for p->thread_info->cpu access. No-op on UP. 2109 */ 2110 #ifdef CONFIG_SMP 2111 2112 static inline unsigned int task_cpu(const struct task_struct *p) 2113 { 2114 return READ_ONCE(task_thread_info(p)->cpu); 2115 } 2116 2117 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2118 2119 #else 2120 2121 static inline unsigned int task_cpu(const struct task_struct *p) 2122 { 2123 return 0; 2124 } 2125 2126 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2127 { 2128 } 2129 2130 #endif /* CONFIG_SMP */ 2131 2132 extern bool sched_task_on_rq(struct task_struct *p); 2133 extern unsigned long get_wchan(struct task_struct *p); 2134 extern struct task_struct *cpu_curr_snapshot(int cpu); 2135 2136 #include <linux/spinlock.h> 2137 2138 /* 2139 * In order to reduce various lock holder preemption latencies provide an 2140 * interface to see if a vCPU is currently running or not. 2141 * 2142 * This allows us to terminate optimistic spin loops and block, analogous to 2143 * the native optimistic spin heuristic of testing if the lock owner task is 2144 * running or not. 2145 */ 2146 #ifndef vcpu_is_preempted 2147 static inline bool vcpu_is_preempted(int cpu) 2148 { 2149 return false; 2150 } 2151 #endif 2152 2153 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2154 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2155 2156 #ifndef TASK_SIZE_OF 2157 #define TASK_SIZE_OF(tsk) TASK_SIZE 2158 #endif 2159 2160 #ifdef CONFIG_SMP 2161 static inline bool owner_on_cpu(struct task_struct *owner) 2162 { 2163 /* 2164 * As lock holder preemption issue, we both skip spinning if 2165 * task is not on cpu or its cpu is preempted 2166 */ 2167 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2168 } 2169 2170 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2171 unsigned long sched_cpu_util(int cpu); 2172 #endif /* CONFIG_SMP */ 2173 2174 #ifdef CONFIG_SCHED_CORE 2175 extern void sched_core_free(struct task_struct *tsk); 2176 extern void sched_core_fork(struct task_struct *p); 2177 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2178 unsigned long uaddr); 2179 extern int sched_core_idle_cpu(int cpu); 2180 #else 2181 static inline void sched_core_free(struct task_struct *tsk) { } 2182 static inline void sched_core_fork(struct task_struct *p) { } 2183 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); } 2184 #endif 2185 2186 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2187 2188 #endif 2189