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 14 #include <linux/pid.h> 15 #include <linux/sem.h> 16 #include <linux/shm.h> 17 #include <linux/mutex.h> 18 #include <linux/plist.h> 19 #include <linux/hrtimer.h> 20 #include <linux/irqflags.h> 21 #include <linux/seccomp.h> 22 #include <linux/nodemask.h> 23 #include <linux/rcupdate.h> 24 #include <linux/refcount.h> 25 #include <linux/resource.h> 26 #include <linux/latencytop.h> 27 #include <linux/sched/prio.h> 28 #include <linux/sched/types.h> 29 #include <linux/signal_types.h> 30 #include <linux/syscall_user_dispatch.h> 31 #include <linux/mm_types_task.h> 32 #include <linux/task_io_accounting.h> 33 #include <linux/posix-timers.h> 34 #include <linux/rseq.h> 35 #include <linux/seqlock.h> 36 #include <linux/kcsan.h> 37 #include <asm/kmap_size.h> 38 39 /* task_struct member predeclarations (sorted alphabetically): */ 40 struct audit_context; 41 struct backing_dev_info; 42 struct bio_list; 43 struct blk_plug; 44 struct bpf_local_storage; 45 struct bpf_run_ctx; 46 struct capture_control; 47 struct cfs_rq; 48 struct fs_struct; 49 struct futex_pi_state; 50 struct io_context; 51 struct io_uring_task; 52 struct mempolicy; 53 struct nameidata; 54 struct nsproxy; 55 struct perf_event_context; 56 struct pid_namespace; 57 struct pipe_inode_info; 58 struct rcu_node; 59 struct reclaim_state; 60 struct robust_list_head; 61 struct root_domain; 62 struct rq; 63 struct sched_attr; 64 struct sched_param; 65 struct seq_file; 66 struct sighand_struct; 67 struct signal_struct; 68 struct task_delay_info; 69 struct task_group; 70 71 /* 72 * Task state bitmask. NOTE! These bits are also 73 * encoded in fs/proc/array.c: get_task_state(). 74 * 75 * We have two separate sets of flags: task->state 76 * is about runnability, while task->exit_state are 77 * about the task exiting. Confusing, but this way 78 * modifying one set can't modify the other one by 79 * mistake. 80 */ 81 82 /* Used in tsk->state: */ 83 #define TASK_RUNNING 0x0000 84 #define TASK_INTERRUPTIBLE 0x0001 85 #define TASK_UNINTERRUPTIBLE 0x0002 86 #define __TASK_STOPPED 0x0004 87 #define __TASK_TRACED 0x0008 88 /* Used in tsk->exit_state: */ 89 #define EXIT_DEAD 0x0010 90 #define EXIT_ZOMBIE 0x0020 91 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 92 /* Used in tsk->state again: */ 93 #define TASK_PARKED 0x0040 94 #define TASK_DEAD 0x0080 95 #define TASK_WAKEKILL 0x0100 96 #define TASK_WAKING 0x0200 97 #define TASK_NOLOAD 0x0400 98 #define TASK_NEW 0x0800 99 /* RT specific auxilliary flag to mark RT lock waiters */ 100 #define TASK_RTLOCK_WAIT 0x1000 101 #define TASK_STATE_MAX 0x2000 102 103 /* Convenience macros for the sake of set_current_state: */ 104 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 105 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 106 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) 107 108 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 109 110 /* Convenience macros for the sake of wake_up(): */ 111 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 112 113 /* get_task_state(): */ 114 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 115 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 116 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 117 TASK_PARKED) 118 119 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 120 121 #define task_is_traced(task) ((READ_ONCE(task->__state) & __TASK_TRACED) != 0) 122 123 #define task_is_stopped(task) ((READ_ONCE(task->__state) & __TASK_STOPPED) != 0) 124 125 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0) 126 127 /* 128 * Special states are those that do not use the normal wait-loop pattern. See 129 * the comment with set_special_state(). 130 */ 131 #define is_special_task_state(state) \ 132 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 133 134 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 135 # define debug_normal_state_change(state_value) \ 136 do { \ 137 WARN_ON_ONCE(is_special_task_state(state_value)); \ 138 current->task_state_change = _THIS_IP_; \ 139 } while (0) 140 141 # define debug_special_state_change(state_value) \ 142 do { \ 143 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 144 current->task_state_change = _THIS_IP_; \ 145 } while (0) 146 147 # define debug_rtlock_wait_set_state() \ 148 do { \ 149 current->saved_state_change = current->task_state_change;\ 150 current->task_state_change = _THIS_IP_; \ 151 } while (0) 152 153 # define debug_rtlock_wait_restore_state() \ 154 do { \ 155 current->task_state_change = current->saved_state_change;\ 156 } while (0) 157 158 #else 159 # define debug_normal_state_change(cond) do { } while (0) 160 # define debug_special_state_change(cond) do { } while (0) 161 # define debug_rtlock_wait_set_state() do { } while (0) 162 # define debug_rtlock_wait_restore_state() do { } while (0) 163 #endif 164 165 /* 166 * set_current_state() includes a barrier so that the write of current->state 167 * is correctly serialised wrt the caller's subsequent test of whether to 168 * actually sleep: 169 * 170 * for (;;) { 171 * set_current_state(TASK_UNINTERRUPTIBLE); 172 * if (CONDITION) 173 * break; 174 * 175 * schedule(); 176 * } 177 * __set_current_state(TASK_RUNNING); 178 * 179 * If the caller does not need such serialisation (because, for instance, the 180 * CONDITION test and condition change and wakeup are under the same lock) then 181 * use __set_current_state(). 182 * 183 * The above is typically ordered against the wakeup, which does: 184 * 185 * CONDITION = 1; 186 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 187 * 188 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 189 * accessing p->state. 190 * 191 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 192 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 193 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 194 * 195 * However, with slightly different timing the wakeup TASK_RUNNING store can 196 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 197 * a problem either because that will result in one extra go around the loop 198 * and our @cond test will save the day. 199 * 200 * Also see the comments of try_to_wake_up(). 201 */ 202 #define __set_current_state(state_value) \ 203 do { \ 204 debug_normal_state_change((state_value)); \ 205 WRITE_ONCE(current->__state, (state_value)); \ 206 } while (0) 207 208 #define set_current_state(state_value) \ 209 do { \ 210 debug_normal_state_change((state_value)); \ 211 smp_store_mb(current->__state, (state_value)); \ 212 } while (0) 213 214 /* 215 * set_special_state() should be used for those states when the blocking task 216 * can not use the regular condition based wait-loop. In that case we must 217 * serialize against wakeups such that any possible in-flight TASK_RUNNING 218 * stores will not collide with our state change. 219 */ 220 #define set_special_state(state_value) \ 221 do { \ 222 unsigned long flags; /* may shadow */ \ 223 \ 224 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 225 debug_special_state_change((state_value)); \ 226 WRITE_ONCE(current->__state, (state_value)); \ 227 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 228 } while (0) 229 230 /* 231 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 232 * 233 * RT's spin/rwlock substitutions are state preserving. The state of the 234 * task when blocking on the lock is saved in task_struct::saved_state and 235 * restored after the lock has been acquired. These operations are 236 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 237 * lock related wakeups while the task is blocked on the lock are 238 * redirected to operate on task_struct::saved_state to ensure that these 239 * are not dropped. On restore task_struct::saved_state is set to 240 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 241 * 242 * The lock operation looks like this: 243 * 244 * current_save_and_set_rtlock_wait_state(); 245 * for (;;) { 246 * if (try_lock()) 247 * break; 248 * raw_spin_unlock_irq(&lock->wait_lock); 249 * schedule_rtlock(); 250 * raw_spin_lock_irq(&lock->wait_lock); 251 * set_current_state(TASK_RTLOCK_WAIT); 252 * } 253 * current_restore_rtlock_saved_state(); 254 */ 255 #define current_save_and_set_rtlock_wait_state() \ 256 do { \ 257 lockdep_assert_irqs_disabled(); \ 258 raw_spin_lock(¤t->pi_lock); \ 259 current->saved_state = current->__state; \ 260 debug_rtlock_wait_set_state(); \ 261 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 262 raw_spin_unlock(¤t->pi_lock); \ 263 } while (0); 264 265 #define current_restore_rtlock_saved_state() \ 266 do { \ 267 lockdep_assert_irqs_disabled(); \ 268 raw_spin_lock(¤t->pi_lock); \ 269 debug_rtlock_wait_restore_state(); \ 270 WRITE_ONCE(current->__state, current->saved_state); \ 271 current->saved_state = TASK_RUNNING; \ 272 raw_spin_unlock(¤t->pi_lock); \ 273 } while (0); 274 275 #define get_current_state() READ_ONCE(current->__state) 276 277 /* Task command name length: */ 278 #define TASK_COMM_LEN 16 279 280 extern void scheduler_tick(void); 281 282 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 283 284 extern long schedule_timeout(long timeout); 285 extern long schedule_timeout_interruptible(long timeout); 286 extern long schedule_timeout_killable(long timeout); 287 extern long schedule_timeout_uninterruptible(long timeout); 288 extern long schedule_timeout_idle(long timeout); 289 asmlinkage void schedule(void); 290 extern void schedule_preempt_disabled(void); 291 asmlinkage void preempt_schedule_irq(void); 292 #ifdef CONFIG_PREEMPT_RT 293 extern void schedule_rtlock(void); 294 #endif 295 296 extern int __must_check io_schedule_prepare(void); 297 extern void io_schedule_finish(int token); 298 extern long io_schedule_timeout(long timeout); 299 extern void io_schedule(void); 300 301 /** 302 * struct prev_cputime - snapshot of system and user cputime 303 * @utime: time spent in user mode 304 * @stime: time spent in system mode 305 * @lock: protects the above two fields 306 * 307 * Stores previous user/system time values such that we can guarantee 308 * monotonicity. 309 */ 310 struct prev_cputime { 311 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 312 u64 utime; 313 u64 stime; 314 raw_spinlock_t lock; 315 #endif 316 }; 317 318 enum vtime_state { 319 /* Task is sleeping or running in a CPU with VTIME inactive: */ 320 VTIME_INACTIVE = 0, 321 /* Task is idle */ 322 VTIME_IDLE, 323 /* Task runs in kernelspace in a CPU with VTIME active: */ 324 VTIME_SYS, 325 /* Task runs in userspace in a CPU with VTIME active: */ 326 VTIME_USER, 327 /* Task runs as guests in a CPU with VTIME active: */ 328 VTIME_GUEST, 329 }; 330 331 struct vtime { 332 seqcount_t seqcount; 333 unsigned long long starttime; 334 enum vtime_state state; 335 unsigned int cpu; 336 u64 utime; 337 u64 stime; 338 u64 gtime; 339 }; 340 341 /* 342 * Utilization clamp constraints. 343 * @UCLAMP_MIN: Minimum utilization 344 * @UCLAMP_MAX: Maximum utilization 345 * @UCLAMP_CNT: Utilization clamp constraints count 346 */ 347 enum uclamp_id { 348 UCLAMP_MIN = 0, 349 UCLAMP_MAX, 350 UCLAMP_CNT 351 }; 352 353 #ifdef CONFIG_SMP 354 extern struct root_domain def_root_domain; 355 extern struct mutex sched_domains_mutex; 356 #endif 357 358 struct sched_info { 359 #ifdef CONFIG_SCHED_INFO 360 /* Cumulative counters: */ 361 362 /* # of times we have run on this CPU: */ 363 unsigned long pcount; 364 365 /* Time spent waiting on a runqueue: */ 366 unsigned long long run_delay; 367 368 /* Timestamps: */ 369 370 /* When did we last run on a CPU? */ 371 unsigned long long last_arrival; 372 373 /* When were we last queued to run? */ 374 unsigned long long last_queued; 375 376 #endif /* CONFIG_SCHED_INFO */ 377 }; 378 379 /* 380 * Integer metrics need fixed point arithmetic, e.g., sched/fair 381 * has a few: load, load_avg, util_avg, freq, and capacity. 382 * 383 * We define a basic fixed point arithmetic range, and then formalize 384 * all these metrics based on that basic range. 385 */ 386 # define SCHED_FIXEDPOINT_SHIFT 10 387 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 388 389 /* Increase resolution of cpu_capacity calculations */ 390 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 391 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 392 393 struct load_weight { 394 unsigned long weight; 395 u32 inv_weight; 396 }; 397 398 /** 399 * struct util_est - Estimation utilization of FAIR tasks 400 * @enqueued: instantaneous estimated utilization of a task/cpu 401 * @ewma: the Exponential Weighted Moving Average (EWMA) 402 * utilization of a task 403 * 404 * Support data structure to track an Exponential Weighted Moving Average 405 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 406 * average each time a task completes an activation. Sample's weight is chosen 407 * so that the EWMA will be relatively insensitive to transient changes to the 408 * task's workload. 409 * 410 * The enqueued attribute has a slightly different meaning for tasks and cpus: 411 * - task: the task's util_avg at last task dequeue time 412 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 413 * Thus, the util_est.enqueued of a task represents the contribution on the 414 * estimated utilization of the CPU where that task is currently enqueued. 415 * 416 * Only for tasks we track a moving average of the past instantaneous 417 * estimated utilization. This allows to absorb sporadic drops in utilization 418 * of an otherwise almost periodic task. 419 * 420 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 421 * updates. When a task is dequeued, its util_est should not be updated if its 422 * util_avg has not been updated in the meantime. 423 * This information is mapped into the MSB bit of util_est.enqueued at dequeue 424 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg 425 * for a task) it is safe to use MSB. 426 */ 427 struct util_est { 428 unsigned int enqueued; 429 unsigned int ewma; 430 #define UTIL_EST_WEIGHT_SHIFT 2 431 #define UTIL_AVG_UNCHANGED 0x80000000 432 } __attribute__((__aligned__(sizeof(u64)))); 433 434 /* 435 * The load/runnable/util_avg accumulates an infinite geometric series 436 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 437 * 438 * [load_avg definition] 439 * 440 * load_avg = runnable% * scale_load_down(load) 441 * 442 * [runnable_avg definition] 443 * 444 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 445 * 446 * [util_avg definition] 447 * 448 * util_avg = running% * SCHED_CAPACITY_SCALE 449 * 450 * where runnable% is the time ratio that a sched_entity is runnable and 451 * running% the time ratio that a sched_entity is running. 452 * 453 * For cfs_rq, they are the aggregated values of all runnable and blocked 454 * sched_entities. 455 * 456 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 457 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 458 * for computing those signals (see update_rq_clock_pelt()) 459 * 460 * N.B., the above ratios (runnable% and running%) themselves are in the 461 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 462 * to as large a range as necessary. This is for example reflected by 463 * util_avg's SCHED_CAPACITY_SCALE. 464 * 465 * [Overflow issue] 466 * 467 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 468 * with the highest load (=88761), always runnable on a single cfs_rq, 469 * and should not overflow as the number already hits PID_MAX_LIMIT. 470 * 471 * For all other cases (including 32-bit kernels), struct load_weight's 472 * weight will overflow first before we do, because: 473 * 474 * Max(load_avg) <= Max(load.weight) 475 * 476 * Then it is the load_weight's responsibility to consider overflow 477 * issues. 478 */ 479 struct sched_avg { 480 u64 last_update_time; 481 u64 load_sum; 482 u64 runnable_sum; 483 u32 util_sum; 484 u32 period_contrib; 485 unsigned long load_avg; 486 unsigned long runnable_avg; 487 unsigned long util_avg; 488 struct util_est util_est; 489 } ____cacheline_aligned; 490 491 struct sched_statistics { 492 #ifdef CONFIG_SCHEDSTATS 493 u64 wait_start; 494 u64 wait_max; 495 u64 wait_count; 496 u64 wait_sum; 497 u64 iowait_count; 498 u64 iowait_sum; 499 500 u64 sleep_start; 501 u64 sleep_max; 502 s64 sum_sleep_runtime; 503 504 u64 block_start; 505 u64 block_max; 506 s64 sum_block_runtime; 507 508 u64 exec_max; 509 u64 slice_max; 510 511 u64 nr_migrations_cold; 512 u64 nr_failed_migrations_affine; 513 u64 nr_failed_migrations_running; 514 u64 nr_failed_migrations_hot; 515 u64 nr_forced_migrations; 516 517 u64 nr_wakeups; 518 u64 nr_wakeups_sync; 519 u64 nr_wakeups_migrate; 520 u64 nr_wakeups_local; 521 u64 nr_wakeups_remote; 522 u64 nr_wakeups_affine; 523 u64 nr_wakeups_affine_attempts; 524 u64 nr_wakeups_passive; 525 u64 nr_wakeups_idle; 526 #endif 527 } ____cacheline_aligned; 528 529 struct sched_entity { 530 /* For load-balancing: */ 531 struct load_weight load; 532 struct rb_node run_node; 533 struct list_head group_node; 534 unsigned int on_rq; 535 536 u64 exec_start; 537 u64 sum_exec_runtime; 538 u64 vruntime; 539 u64 prev_sum_exec_runtime; 540 541 u64 nr_migrations; 542 543 #ifdef CONFIG_FAIR_GROUP_SCHED 544 int depth; 545 struct sched_entity *parent; 546 /* rq on which this entity is (to be) queued: */ 547 struct cfs_rq *cfs_rq; 548 /* rq "owned" by this entity/group: */ 549 struct cfs_rq *my_q; 550 /* cached value of my_q->h_nr_running */ 551 unsigned long runnable_weight; 552 #endif 553 554 #ifdef CONFIG_SMP 555 /* 556 * Per entity load average tracking. 557 * 558 * Put into separate cache line so it does not 559 * collide with read-mostly values above. 560 */ 561 struct sched_avg avg; 562 #endif 563 }; 564 565 struct sched_rt_entity { 566 struct list_head run_list; 567 unsigned long timeout; 568 unsigned long watchdog_stamp; 569 unsigned int time_slice; 570 unsigned short on_rq; 571 unsigned short on_list; 572 573 struct sched_rt_entity *back; 574 #ifdef CONFIG_RT_GROUP_SCHED 575 struct sched_rt_entity *parent; 576 /* rq on which this entity is (to be) queued: */ 577 struct rt_rq *rt_rq; 578 /* rq "owned" by this entity/group: */ 579 struct rt_rq *my_q; 580 #endif 581 } __randomize_layout; 582 583 struct sched_dl_entity { 584 struct rb_node rb_node; 585 586 /* 587 * Original scheduling parameters. Copied here from sched_attr 588 * during sched_setattr(), they will remain the same until 589 * the next sched_setattr(). 590 */ 591 u64 dl_runtime; /* Maximum runtime for each instance */ 592 u64 dl_deadline; /* Relative deadline of each instance */ 593 u64 dl_period; /* Separation of two instances (period) */ 594 u64 dl_bw; /* dl_runtime / dl_period */ 595 u64 dl_density; /* dl_runtime / dl_deadline */ 596 597 /* 598 * Actual scheduling parameters. Initialized with the values above, 599 * they are continuously updated during task execution. Note that 600 * the remaining runtime could be < 0 in case we are in overrun. 601 */ 602 s64 runtime; /* Remaining runtime for this instance */ 603 u64 deadline; /* Absolute deadline for this instance */ 604 unsigned int flags; /* Specifying the scheduler behaviour */ 605 606 /* 607 * Some bool flags: 608 * 609 * @dl_throttled tells if we exhausted the runtime. If so, the 610 * task has to wait for a replenishment to be performed at the 611 * next firing of dl_timer. 612 * 613 * @dl_boosted tells if we are boosted due to DI. If so we are 614 * outside bandwidth enforcement mechanism (but only until we 615 * exit the critical section); 616 * 617 * @dl_yielded tells if task gave up the CPU before consuming 618 * all its available runtime during the last job. 619 * 620 * @dl_non_contending tells if the task is inactive while still 621 * contributing to the active utilization. In other words, it 622 * indicates if the inactive timer has been armed and its handler 623 * has not been executed yet. This flag is useful to avoid race 624 * conditions between the inactive timer handler and the wakeup 625 * code. 626 * 627 * @dl_overrun tells if the task asked to be informed about runtime 628 * overruns. 629 */ 630 unsigned int dl_throttled : 1; 631 unsigned int dl_yielded : 1; 632 unsigned int dl_non_contending : 1; 633 unsigned int dl_overrun : 1; 634 635 /* 636 * Bandwidth enforcement timer. Each -deadline task has its 637 * own bandwidth to be enforced, thus we need one timer per task. 638 */ 639 struct hrtimer dl_timer; 640 641 /* 642 * Inactive timer, responsible for decreasing the active utilization 643 * at the "0-lag time". When a -deadline task blocks, it contributes 644 * to GRUB's active utilization until the "0-lag time", hence a 645 * timer is needed to decrease the active utilization at the correct 646 * time. 647 */ 648 struct hrtimer inactive_timer; 649 650 #ifdef CONFIG_RT_MUTEXES 651 /* 652 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 653 * pi_se points to the donor, otherwise points to the dl_se it belongs 654 * to (the original one/itself). 655 */ 656 struct sched_dl_entity *pi_se; 657 #endif 658 }; 659 660 #ifdef CONFIG_UCLAMP_TASK 661 /* Number of utilization clamp buckets (shorter alias) */ 662 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 663 664 /* 665 * Utilization clamp for a scheduling entity 666 * @value: clamp value "assigned" to a se 667 * @bucket_id: bucket index corresponding to the "assigned" value 668 * @active: the se is currently refcounted in a rq's bucket 669 * @user_defined: the requested clamp value comes from user-space 670 * 671 * The bucket_id is the index of the clamp bucket matching the clamp value 672 * which is pre-computed and stored to avoid expensive integer divisions from 673 * the fast path. 674 * 675 * The active bit is set whenever a task has got an "effective" value assigned, 676 * which can be different from the clamp value "requested" from user-space. 677 * This allows to know a task is refcounted in the rq's bucket corresponding 678 * to the "effective" bucket_id. 679 * 680 * The user_defined bit is set whenever a task has got a task-specific clamp 681 * value requested from userspace, i.e. the system defaults apply to this task 682 * just as a restriction. This allows to relax default clamps when a less 683 * restrictive task-specific value has been requested, thus allowing to 684 * implement a "nice" semantic. For example, a task running with a 20% 685 * default boost can still drop its own boosting to 0%. 686 */ 687 struct uclamp_se { 688 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 689 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 690 unsigned int active : 1; 691 unsigned int user_defined : 1; 692 }; 693 #endif /* CONFIG_UCLAMP_TASK */ 694 695 union rcu_special { 696 struct { 697 u8 blocked; 698 u8 need_qs; 699 u8 exp_hint; /* Hint for performance. */ 700 u8 need_mb; /* Readers need smp_mb(). */ 701 } b; /* Bits. */ 702 u32 s; /* Set of bits. */ 703 }; 704 705 enum perf_event_task_context { 706 perf_invalid_context = -1, 707 perf_hw_context = 0, 708 perf_sw_context, 709 perf_nr_task_contexts, 710 }; 711 712 struct wake_q_node { 713 struct wake_q_node *next; 714 }; 715 716 struct kmap_ctrl { 717 #ifdef CONFIG_KMAP_LOCAL 718 int idx; 719 pte_t pteval[KM_MAX_IDX]; 720 #endif 721 }; 722 723 struct task_struct { 724 #ifdef CONFIG_THREAD_INFO_IN_TASK 725 /* 726 * For reasons of header soup (see current_thread_info()), this 727 * must be the first element of task_struct. 728 */ 729 struct thread_info thread_info; 730 #endif 731 unsigned int __state; 732 733 #ifdef CONFIG_PREEMPT_RT 734 /* saved state for "spinlock sleepers" */ 735 unsigned int saved_state; 736 #endif 737 738 /* 739 * This begins the randomizable portion of task_struct. Only 740 * scheduling-critical items should be added above here. 741 */ 742 randomized_struct_fields_start 743 744 void *stack; 745 refcount_t usage; 746 /* Per task flags (PF_*), defined further below: */ 747 unsigned int flags; 748 unsigned int ptrace; 749 750 #ifdef CONFIG_SMP 751 int on_cpu; 752 struct __call_single_node wake_entry; 753 unsigned int wakee_flips; 754 unsigned long wakee_flip_decay_ts; 755 struct task_struct *last_wakee; 756 757 /* 758 * recent_used_cpu is initially set as the last CPU used by a task 759 * that wakes affine another task. Waker/wakee relationships can 760 * push tasks around a CPU where each wakeup moves to the next one. 761 * Tracking a recently used CPU allows a quick search for a recently 762 * used CPU that may be idle. 763 */ 764 int recent_used_cpu; 765 int wake_cpu; 766 #endif 767 int on_rq; 768 769 int prio; 770 int static_prio; 771 int normal_prio; 772 unsigned int rt_priority; 773 774 struct sched_entity se; 775 struct sched_rt_entity rt; 776 struct sched_dl_entity dl; 777 const struct sched_class *sched_class; 778 779 #ifdef CONFIG_SCHED_CORE 780 struct rb_node core_node; 781 unsigned long core_cookie; 782 unsigned int core_occupation; 783 #endif 784 785 #ifdef CONFIG_CGROUP_SCHED 786 struct task_group *sched_task_group; 787 #endif 788 789 #ifdef CONFIG_UCLAMP_TASK 790 /* 791 * Clamp values requested for a scheduling entity. 792 * Must be updated with task_rq_lock() held. 793 */ 794 struct uclamp_se uclamp_req[UCLAMP_CNT]; 795 /* 796 * Effective clamp values used for a scheduling entity. 797 * Must be updated with task_rq_lock() held. 798 */ 799 struct uclamp_se uclamp[UCLAMP_CNT]; 800 #endif 801 802 struct sched_statistics stats; 803 804 #ifdef CONFIG_PREEMPT_NOTIFIERS 805 /* List of struct preempt_notifier: */ 806 struct hlist_head preempt_notifiers; 807 #endif 808 809 #ifdef CONFIG_BLK_DEV_IO_TRACE 810 unsigned int btrace_seq; 811 #endif 812 813 unsigned int policy; 814 int nr_cpus_allowed; 815 const cpumask_t *cpus_ptr; 816 cpumask_t *user_cpus_ptr; 817 cpumask_t cpus_mask; 818 void *migration_pending; 819 #ifdef CONFIG_SMP 820 unsigned short migration_disabled; 821 #endif 822 unsigned short migration_flags; 823 824 #ifdef CONFIG_PREEMPT_RCU 825 int rcu_read_lock_nesting; 826 union rcu_special rcu_read_unlock_special; 827 struct list_head rcu_node_entry; 828 struct rcu_node *rcu_blocked_node; 829 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 830 831 #ifdef CONFIG_TASKS_RCU 832 unsigned long rcu_tasks_nvcsw; 833 u8 rcu_tasks_holdout; 834 u8 rcu_tasks_idx; 835 int rcu_tasks_idle_cpu; 836 struct list_head rcu_tasks_holdout_list; 837 #endif /* #ifdef CONFIG_TASKS_RCU */ 838 839 #ifdef CONFIG_TASKS_TRACE_RCU 840 int trc_reader_nesting; 841 int trc_ipi_to_cpu; 842 union rcu_special trc_reader_special; 843 bool trc_reader_checked; 844 struct list_head trc_holdout_list; 845 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 846 847 struct sched_info sched_info; 848 849 struct list_head tasks; 850 #ifdef CONFIG_SMP 851 struct plist_node pushable_tasks; 852 struct rb_node pushable_dl_tasks; 853 #endif 854 855 struct mm_struct *mm; 856 struct mm_struct *active_mm; 857 858 /* Per-thread vma caching: */ 859 struct vmacache vmacache; 860 861 #ifdef SPLIT_RSS_COUNTING 862 struct task_rss_stat rss_stat; 863 #endif 864 int exit_state; 865 int exit_code; 866 int exit_signal; 867 /* The signal sent when the parent dies: */ 868 int pdeath_signal; 869 /* JOBCTL_*, siglock protected: */ 870 unsigned long jobctl; 871 872 /* Used for emulating ABI behavior of previous Linux versions: */ 873 unsigned int personality; 874 875 /* Scheduler bits, serialized by scheduler locks: */ 876 unsigned sched_reset_on_fork:1; 877 unsigned sched_contributes_to_load:1; 878 unsigned sched_migrated:1; 879 #ifdef CONFIG_PSI 880 unsigned sched_psi_wake_requeue:1; 881 #endif 882 883 /* Force alignment to the next boundary: */ 884 unsigned :0; 885 886 /* Unserialized, strictly 'current' */ 887 888 /* 889 * This field must not be in the scheduler word above due to wakelist 890 * queueing no longer being serialized by p->on_cpu. However: 891 * 892 * p->XXX = X; ttwu() 893 * schedule() if (p->on_rq && ..) // false 894 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 895 * deactivate_task() ttwu_queue_wakelist()) 896 * p->on_rq = 0; p->sched_remote_wakeup = Y; 897 * 898 * guarantees all stores of 'current' are visible before 899 * ->sched_remote_wakeup gets used, so it can be in this word. 900 */ 901 unsigned sched_remote_wakeup:1; 902 903 /* Bit to tell LSMs we're in execve(): */ 904 unsigned in_execve:1; 905 unsigned in_iowait:1; 906 #ifndef TIF_RESTORE_SIGMASK 907 unsigned restore_sigmask:1; 908 #endif 909 #ifdef CONFIG_MEMCG 910 unsigned in_user_fault:1; 911 #endif 912 #ifdef CONFIG_COMPAT_BRK 913 unsigned brk_randomized:1; 914 #endif 915 #ifdef CONFIG_CGROUPS 916 /* disallow userland-initiated cgroup migration */ 917 unsigned no_cgroup_migration:1; 918 /* task is frozen/stopped (used by the cgroup freezer) */ 919 unsigned frozen:1; 920 #endif 921 #ifdef CONFIG_BLK_CGROUP 922 unsigned use_memdelay:1; 923 #endif 924 #ifdef CONFIG_PSI 925 /* Stalled due to lack of memory */ 926 unsigned in_memstall:1; 927 #endif 928 #ifdef CONFIG_PAGE_OWNER 929 /* Used by page_owner=on to detect recursion in page tracking. */ 930 unsigned in_page_owner:1; 931 #endif 932 #ifdef CONFIG_EVENTFD 933 /* Recursion prevention for eventfd_signal() */ 934 unsigned in_eventfd_signal:1; 935 #endif 936 937 unsigned long atomic_flags; /* Flags requiring atomic access. */ 938 939 struct restart_block restart_block; 940 941 pid_t pid; 942 pid_t tgid; 943 944 #ifdef CONFIG_STACKPROTECTOR 945 /* Canary value for the -fstack-protector GCC feature: */ 946 unsigned long stack_canary; 947 #endif 948 /* 949 * Pointers to the (original) parent process, youngest child, younger sibling, 950 * older sibling, respectively. (p->father can be replaced with 951 * p->real_parent->pid) 952 */ 953 954 /* Real parent process: */ 955 struct task_struct __rcu *real_parent; 956 957 /* Recipient of SIGCHLD, wait4() reports: */ 958 struct task_struct __rcu *parent; 959 960 /* 961 * Children/sibling form the list of natural children: 962 */ 963 struct list_head children; 964 struct list_head sibling; 965 struct task_struct *group_leader; 966 967 /* 968 * 'ptraced' is the list of tasks this task is using ptrace() on. 969 * 970 * This includes both natural children and PTRACE_ATTACH targets. 971 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 972 */ 973 struct list_head ptraced; 974 struct list_head ptrace_entry; 975 976 /* PID/PID hash table linkage. */ 977 struct pid *thread_pid; 978 struct hlist_node pid_links[PIDTYPE_MAX]; 979 struct list_head thread_group; 980 struct list_head thread_node; 981 982 struct completion *vfork_done; 983 984 /* CLONE_CHILD_SETTID: */ 985 int __user *set_child_tid; 986 987 /* CLONE_CHILD_CLEARTID: */ 988 int __user *clear_child_tid; 989 990 /* PF_IO_WORKER */ 991 void *pf_io_worker; 992 993 u64 utime; 994 u64 stime; 995 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 996 u64 utimescaled; 997 u64 stimescaled; 998 #endif 999 u64 gtime; 1000 struct prev_cputime prev_cputime; 1001 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1002 struct vtime vtime; 1003 #endif 1004 1005 #ifdef CONFIG_NO_HZ_FULL 1006 atomic_t tick_dep_mask; 1007 #endif 1008 /* Context switch counts: */ 1009 unsigned long nvcsw; 1010 unsigned long nivcsw; 1011 1012 /* Monotonic time in nsecs: */ 1013 u64 start_time; 1014 1015 /* Boot based time in nsecs: */ 1016 u64 start_boottime; 1017 1018 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1019 unsigned long min_flt; 1020 unsigned long maj_flt; 1021 1022 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1023 struct posix_cputimers posix_cputimers; 1024 1025 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1026 struct posix_cputimers_work posix_cputimers_work; 1027 #endif 1028 1029 /* Process credentials: */ 1030 1031 /* Tracer's credentials at attach: */ 1032 const struct cred __rcu *ptracer_cred; 1033 1034 /* Objective and real subjective task credentials (COW): */ 1035 const struct cred __rcu *real_cred; 1036 1037 /* Effective (overridable) subjective task credentials (COW): */ 1038 const struct cred __rcu *cred; 1039 1040 #ifdef CONFIG_KEYS 1041 /* Cached requested key. */ 1042 struct key *cached_requested_key; 1043 #endif 1044 1045 /* 1046 * executable name, excluding path. 1047 * 1048 * - normally initialized setup_new_exec() 1049 * - access it with [gs]et_task_comm() 1050 * - lock it with task_lock() 1051 */ 1052 char comm[TASK_COMM_LEN]; 1053 1054 struct nameidata *nameidata; 1055 1056 #ifdef CONFIG_SYSVIPC 1057 struct sysv_sem sysvsem; 1058 struct sysv_shm sysvshm; 1059 #endif 1060 #ifdef CONFIG_DETECT_HUNG_TASK 1061 unsigned long last_switch_count; 1062 unsigned long last_switch_time; 1063 #endif 1064 /* Filesystem information: */ 1065 struct fs_struct *fs; 1066 1067 /* Open file information: */ 1068 struct files_struct *files; 1069 1070 #ifdef CONFIG_IO_URING 1071 struct io_uring_task *io_uring; 1072 #endif 1073 1074 /* Namespaces: */ 1075 struct nsproxy *nsproxy; 1076 1077 /* Signal handlers: */ 1078 struct signal_struct *signal; 1079 struct sighand_struct __rcu *sighand; 1080 sigset_t blocked; 1081 sigset_t real_blocked; 1082 /* Restored if set_restore_sigmask() was used: */ 1083 sigset_t saved_sigmask; 1084 struct sigpending pending; 1085 unsigned long sas_ss_sp; 1086 size_t sas_ss_size; 1087 unsigned int sas_ss_flags; 1088 1089 struct callback_head *task_works; 1090 1091 #ifdef CONFIG_AUDIT 1092 #ifdef CONFIG_AUDITSYSCALL 1093 struct audit_context *audit_context; 1094 #endif 1095 kuid_t loginuid; 1096 unsigned int sessionid; 1097 #endif 1098 struct seccomp seccomp; 1099 struct syscall_user_dispatch syscall_dispatch; 1100 1101 /* Thread group tracking: */ 1102 u64 parent_exec_id; 1103 u64 self_exec_id; 1104 1105 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1106 spinlock_t alloc_lock; 1107 1108 /* Protection of the PI data structures: */ 1109 raw_spinlock_t pi_lock; 1110 1111 struct wake_q_node wake_q; 1112 1113 #ifdef CONFIG_RT_MUTEXES 1114 /* PI waiters blocked on a rt_mutex held by this task: */ 1115 struct rb_root_cached pi_waiters; 1116 /* Updated under owner's pi_lock and rq lock */ 1117 struct task_struct *pi_top_task; 1118 /* Deadlock detection and priority inheritance handling: */ 1119 struct rt_mutex_waiter *pi_blocked_on; 1120 #endif 1121 1122 #ifdef CONFIG_DEBUG_MUTEXES 1123 /* Mutex deadlock detection: */ 1124 struct mutex_waiter *blocked_on; 1125 #endif 1126 1127 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1128 int non_block_count; 1129 #endif 1130 1131 #ifdef CONFIG_TRACE_IRQFLAGS 1132 struct irqtrace_events irqtrace; 1133 unsigned int hardirq_threaded; 1134 u64 hardirq_chain_key; 1135 int softirqs_enabled; 1136 int softirq_context; 1137 int irq_config; 1138 #endif 1139 #ifdef CONFIG_PREEMPT_RT 1140 int softirq_disable_cnt; 1141 #endif 1142 1143 #ifdef CONFIG_LOCKDEP 1144 # define MAX_LOCK_DEPTH 48UL 1145 u64 curr_chain_key; 1146 int lockdep_depth; 1147 unsigned int lockdep_recursion; 1148 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1149 #endif 1150 1151 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1152 unsigned int in_ubsan; 1153 #endif 1154 1155 /* Journalling filesystem info: */ 1156 void *journal_info; 1157 1158 /* Stacked block device info: */ 1159 struct bio_list *bio_list; 1160 1161 /* Stack plugging: */ 1162 struct blk_plug *plug; 1163 1164 /* VM state: */ 1165 struct reclaim_state *reclaim_state; 1166 1167 struct backing_dev_info *backing_dev_info; 1168 1169 struct io_context *io_context; 1170 1171 #ifdef CONFIG_COMPACTION 1172 struct capture_control *capture_control; 1173 #endif 1174 /* Ptrace state: */ 1175 unsigned long ptrace_message; 1176 kernel_siginfo_t *last_siginfo; 1177 1178 struct task_io_accounting ioac; 1179 #ifdef CONFIG_PSI 1180 /* Pressure stall state */ 1181 unsigned int psi_flags; 1182 #endif 1183 #ifdef CONFIG_TASK_XACCT 1184 /* Accumulated RSS usage: */ 1185 u64 acct_rss_mem1; 1186 /* Accumulated virtual memory usage: */ 1187 u64 acct_vm_mem1; 1188 /* stime + utime since last update: */ 1189 u64 acct_timexpd; 1190 #endif 1191 #ifdef CONFIG_CPUSETS 1192 /* Protected by ->alloc_lock: */ 1193 nodemask_t mems_allowed; 1194 /* Sequence number to catch updates: */ 1195 seqcount_spinlock_t mems_allowed_seq; 1196 int cpuset_mem_spread_rotor; 1197 int cpuset_slab_spread_rotor; 1198 #endif 1199 #ifdef CONFIG_CGROUPS 1200 /* Control Group info protected by css_set_lock: */ 1201 struct css_set __rcu *cgroups; 1202 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1203 struct list_head cg_list; 1204 #endif 1205 #ifdef CONFIG_X86_CPU_RESCTRL 1206 u32 closid; 1207 u32 rmid; 1208 #endif 1209 #ifdef CONFIG_FUTEX 1210 struct robust_list_head __user *robust_list; 1211 #ifdef CONFIG_COMPAT 1212 struct compat_robust_list_head __user *compat_robust_list; 1213 #endif 1214 struct list_head pi_state_list; 1215 struct futex_pi_state *pi_state_cache; 1216 struct mutex futex_exit_mutex; 1217 unsigned int futex_state; 1218 #endif 1219 #ifdef CONFIG_PERF_EVENTS 1220 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 1221 struct mutex perf_event_mutex; 1222 struct list_head perf_event_list; 1223 #endif 1224 #ifdef CONFIG_DEBUG_PREEMPT 1225 unsigned long preempt_disable_ip; 1226 #endif 1227 #ifdef CONFIG_NUMA 1228 /* Protected by alloc_lock: */ 1229 struct mempolicy *mempolicy; 1230 short il_prev; 1231 short pref_node_fork; 1232 #endif 1233 #ifdef CONFIG_NUMA_BALANCING 1234 int numa_scan_seq; 1235 unsigned int numa_scan_period; 1236 unsigned int numa_scan_period_max; 1237 int numa_preferred_nid; 1238 unsigned long numa_migrate_retry; 1239 /* Migration stamp: */ 1240 u64 node_stamp; 1241 u64 last_task_numa_placement; 1242 u64 last_sum_exec_runtime; 1243 struct callback_head numa_work; 1244 1245 /* 1246 * This pointer is only modified for current in syscall and 1247 * pagefault context (and for tasks being destroyed), so it can be read 1248 * from any of the following contexts: 1249 * - RCU read-side critical section 1250 * - current->numa_group from everywhere 1251 * - task's runqueue locked, task not running 1252 */ 1253 struct numa_group __rcu *numa_group; 1254 1255 /* 1256 * numa_faults is an array split into four regions: 1257 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1258 * in this precise order. 1259 * 1260 * faults_memory: Exponential decaying average of faults on a per-node 1261 * basis. Scheduling placement decisions are made based on these 1262 * counts. The values remain static for the duration of a PTE scan. 1263 * faults_cpu: Track the nodes the process was running on when a NUMA 1264 * hinting fault was incurred. 1265 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1266 * during the current scan window. When the scan completes, the counts 1267 * in faults_memory and faults_cpu decay and these values are copied. 1268 */ 1269 unsigned long *numa_faults; 1270 unsigned long total_numa_faults; 1271 1272 /* 1273 * numa_faults_locality tracks if faults recorded during the last 1274 * scan window were remote/local or failed to migrate. The task scan 1275 * period is adapted based on the locality of the faults with different 1276 * weights depending on whether they were shared or private faults 1277 */ 1278 unsigned long numa_faults_locality[3]; 1279 1280 unsigned long numa_pages_migrated; 1281 #endif /* CONFIG_NUMA_BALANCING */ 1282 1283 #ifdef CONFIG_RSEQ 1284 struct rseq __user *rseq; 1285 u32 rseq_sig; 1286 /* 1287 * RmW on rseq_event_mask must be performed atomically 1288 * with respect to preemption. 1289 */ 1290 unsigned long rseq_event_mask; 1291 #endif 1292 1293 struct tlbflush_unmap_batch tlb_ubc; 1294 1295 union { 1296 refcount_t rcu_users; 1297 struct rcu_head rcu; 1298 }; 1299 1300 /* Cache last used pipe for splice(): */ 1301 struct pipe_inode_info *splice_pipe; 1302 1303 struct page_frag task_frag; 1304 1305 #ifdef CONFIG_TASK_DELAY_ACCT 1306 struct task_delay_info *delays; 1307 #endif 1308 1309 #ifdef CONFIG_FAULT_INJECTION 1310 int make_it_fail; 1311 unsigned int fail_nth; 1312 #endif 1313 /* 1314 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1315 * balance_dirty_pages() for a dirty throttling pause: 1316 */ 1317 int nr_dirtied; 1318 int nr_dirtied_pause; 1319 /* Start of a write-and-pause period: */ 1320 unsigned long dirty_paused_when; 1321 1322 #ifdef CONFIG_LATENCYTOP 1323 int latency_record_count; 1324 struct latency_record latency_record[LT_SAVECOUNT]; 1325 #endif 1326 /* 1327 * Time slack values; these are used to round up poll() and 1328 * select() etc timeout values. These are in nanoseconds. 1329 */ 1330 u64 timer_slack_ns; 1331 u64 default_timer_slack_ns; 1332 1333 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1334 unsigned int kasan_depth; 1335 #endif 1336 1337 #ifdef CONFIG_KCSAN 1338 struct kcsan_ctx kcsan_ctx; 1339 #ifdef CONFIG_TRACE_IRQFLAGS 1340 struct irqtrace_events kcsan_save_irqtrace; 1341 #endif 1342 #endif 1343 1344 #if IS_ENABLED(CONFIG_KUNIT) 1345 struct kunit *kunit_test; 1346 #endif 1347 1348 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1349 /* Index of current stored address in ret_stack: */ 1350 int curr_ret_stack; 1351 int curr_ret_depth; 1352 1353 /* Stack of return addresses for return function tracing: */ 1354 struct ftrace_ret_stack *ret_stack; 1355 1356 /* Timestamp for last schedule: */ 1357 unsigned long long ftrace_timestamp; 1358 1359 /* 1360 * Number of functions that haven't been traced 1361 * because of depth overrun: 1362 */ 1363 atomic_t trace_overrun; 1364 1365 /* Pause tracing: */ 1366 atomic_t tracing_graph_pause; 1367 #endif 1368 1369 #ifdef CONFIG_TRACING 1370 /* State flags for use by tracers: */ 1371 unsigned long trace; 1372 1373 /* Bitmask and counter of trace recursion: */ 1374 unsigned long trace_recursion; 1375 #endif /* CONFIG_TRACING */ 1376 1377 #ifdef CONFIG_KCOV 1378 /* See kernel/kcov.c for more details. */ 1379 1380 /* Coverage collection mode enabled for this task (0 if disabled): */ 1381 unsigned int kcov_mode; 1382 1383 /* Size of the kcov_area: */ 1384 unsigned int kcov_size; 1385 1386 /* Buffer for coverage collection: */ 1387 void *kcov_area; 1388 1389 /* KCOV descriptor wired with this task or NULL: */ 1390 struct kcov *kcov; 1391 1392 /* KCOV common handle for remote coverage collection: */ 1393 u64 kcov_handle; 1394 1395 /* KCOV sequence number: */ 1396 int kcov_sequence; 1397 1398 /* Collect coverage from softirq context: */ 1399 unsigned int kcov_softirq; 1400 #endif 1401 1402 #ifdef CONFIG_MEMCG 1403 struct mem_cgroup *memcg_in_oom; 1404 gfp_t memcg_oom_gfp_mask; 1405 int memcg_oom_order; 1406 1407 /* Number of pages to reclaim on returning to userland: */ 1408 unsigned int memcg_nr_pages_over_high; 1409 1410 /* Used by memcontrol for targeted memcg charge: */ 1411 struct mem_cgroup *active_memcg; 1412 #endif 1413 1414 #ifdef CONFIG_BLK_CGROUP 1415 struct request_queue *throttle_queue; 1416 #endif 1417 1418 #ifdef CONFIG_UPROBES 1419 struct uprobe_task *utask; 1420 #endif 1421 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1422 unsigned int sequential_io; 1423 unsigned int sequential_io_avg; 1424 #endif 1425 struct kmap_ctrl kmap_ctrl; 1426 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1427 unsigned long task_state_change; 1428 # ifdef CONFIG_PREEMPT_RT 1429 unsigned long saved_state_change; 1430 # endif 1431 #endif 1432 int pagefault_disabled; 1433 #ifdef CONFIG_MMU 1434 struct task_struct *oom_reaper_list; 1435 #endif 1436 #ifdef CONFIG_VMAP_STACK 1437 struct vm_struct *stack_vm_area; 1438 #endif 1439 #ifdef CONFIG_THREAD_INFO_IN_TASK 1440 /* A live task holds one reference: */ 1441 refcount_t stack_refcount; 1442 #endif 1443 #ifdef CONFIG_LIVEPATCH 1444 int patch_state; 1445 #endif 1446 #ifdef CONFIG_SECURITY 1447 /* Used by LSM modules for access restriction: */ 1448 void *security; 1449 #endif 1450 #ifdef CONFIG_BPF_SYSCALL 1451 /* Used by BPF task local storage */ 1452 struct bpf_local_storage __rcu *bpf_storage; 1453 /* Used for BPF run context */ 1454 struct bpf_run_ctx *bpf_ctx; 1455 #endif 1456 1457 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1458 unsigned long lowest_stack; 1459 unsigned long prev_lowest_stack; 1460 #endif 1461 1462 #ifdef CONFIG_X86_MCE 1463 void __user *mce_vaddr; 1464 __u64 mce_kflags; 1465 u64 mce_addr; 1466 __u64 mce_ripv : 1, 1467 mce_whole_page : 1, 1468 __mce_reserved : 62; 1469 struct callback_head mce_kill_me; 1470 int mce_count; 1471 #endif 1472 1473 #ifdef CONFIG_KRETPROBES 1474 struct llist_head kretprobe_instances; 1475 #endif 1476 1477 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1478 /* 1479 * If L1D flush is supported on mm context switch 1480 * then we use this callback head to queue kill work 1481 * to kill tasks that are not running on SMT disabled 1482 * cores 1483 */ 1484 struct callback_head l1d_flush_kill; 1485 #endif 1486 1487 /* 1488 * New fields for task_struct should be added above here, so that 1489 * they are included in the randomized portion of task_struct. 1490 */ 1491 randomized_struct_fields_end 1492 1493 /* CPU-specific state of this task: */ 1494 struct thread_struct thread; 1495 1496 /* 1497 * WARNING: on x86, 'thread_struct' contains a variable-sized 1498 * structure. It *MUST* be at the end of 'task_struct'. 1499 * 1500 * Do not put anything below here! 1501 */ 1502 }; 1503 1504 static inline struct pid *task_pid(struct task_struct *task) 1505 { 1506 return task->thread_pid; 1507 } 1508 1509 /* 1510 * the helpers to get the task's different pids as they are seen 1511 * from various namespaces 1512 * 1513 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1514 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1515 * current. 1516 * task_xid_nr_ns() : id seen from the ns specified; 1517 * 1518 * see also pid_nr() etc in include/linux/pid.h 1519 */ 1520 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1521 1522 static inline pid_t task_pid_nr(struct task_struct *tsk) 1523 { 1524 return tsk->pid; 1525 } 1526 1527 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1528 { 1529 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1530 } 1531 1532 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1533 { 1534 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1535 } 1536 1537 1538 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1539 { 1540 return tsk->tgid; 1541 } 1542 1543 /** 1544 * pid_alive - check that a task structure is not stale 1545 * @p: Task structure to be checked. 1546 * 1547 * Test if a process is not yet dead (at most zombie state) 1548 * If pid_alive fails, then pointers within the task structure 1549 * can be stale and must not be dereferenced. 1550 * 1551 * Return: 1 if the process is alive. 0 otherwise. 1552 */ 1553 static inline int pid_alive(const struct task_struct *p) 1554 { 1555 return p->thread_pid != NULL; 1556 } 1557 1558 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1559 { 1560 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1561 } 1562 1563 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1564 { 1565 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1566 } 1567 1568 1569 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1570 { 1571 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1572 } 1573 1574 static inline pid_t task_session_vnr(struct task_struct *tsk) 1575 { 1576 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1577 } 1578 1579 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1580 { 1581 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1582 } 1583 1584 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1585 { 1586 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1587 } 1588 1589 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1590 { 1591 pid_t pid = 0; 1592 1593 rcu_read_lock(); 1594 if (pid_alive(tsk)) 1595 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1596 rcu_read_unlock(); 1597 1598 return pid; 1599 } 1600 1601 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1602 { 1603 return task_ppid_nr_ns(tsk, &init_pid_ns); 1604 } 1605 1606 /* Obsolete, do not use: */ 1607 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1608 { 1609 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1610 } 1611 1612 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1613 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1614 1615 static inline unsigned int task_state_index(struct task_struct *tsk) 1616 { 1617 unsigned int tsk_state = READ_ONCE(tsk->__state); 1618 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT; 1619 1620 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1621 1622 if (tsk_state == TASK_IDLE) 1623 state = TASK_REPORT_IDLE; 1624 1625 return fls(state); 1626 } 1627 1628 static inline char task_index_to_char(unsigned int state) 1629 { 1630 static const char state_char[] = "RSDTtXZPI"; 1631 1632 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1633 1634 return state_char[state]; 1635 } 1636 1637 static inline char task_state_to_char(struct task_struct *tsk) 1638 { 1639 return task_index_to_char(task_state_index(tsk)); 1640 } 1641 1642 /** 1643 * is_global_init - check if a task structure is init. Since init 1644 * is free to have sub-threads we need to check tgid. 1645 * @tsk: Task structure to be checked. 1646 * 1647 * Check if a task structure is the first user space task the kernel created. 1648 * 1649 * Return: 1 if the task structure is init. 0 otherwise. 1650 */ 1651 static inline int is_global_init(struct task_struct *tsk) 1652 { 1653 return task_tgid_nr(tsk) == 1; 1654 } 1655 1656 extern struct pid *cad_pid; 1657 1658 /* 1659 * Per process flags 1660 */ 1661 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1662 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1663 #define PF_EXITING 0x00000004 /* Getting shut down */ 1664 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1665 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1666 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1667 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1668 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1669 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1670 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1671 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1672 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1673 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1674 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1675 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */ 1676 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1677 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1678 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1679 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1680 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1681 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1682 * I am cleaning dirty pages from some other bdi. */ 1683 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1684 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1685 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ 1686 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1687 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1688 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1689 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1690 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1691 1692 /* 1693 * Only the _current_ task can read/write to tsk->flags, but other 1694 * tasks can access tsk->flags in readonly mode for example 1695 * with tsk_used_math (like during threaded core dumping). 1696 * There is however an exception to this rule during ptrace 1697 * or during fork: the ptracer task is allowed to write to the 1698 * child->flags of its traced child (same goes for fork, the parent 1699 * can write to the child->flags), because we're guaranteed the 1700 * child is not running and in turn not changing child->flags 1701 * at the same time the parent does it. 1702 */ 1703 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1704 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1705 #define clear_used_math() clear_stopped_child_used_math(current) 1706 #define set_used_math() set_stopped_child_used_math(current) 1707 1708 #define conditional_stopped_child_used_math(condition, child) \ 1709 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1710 1711 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1712 1713 #define copy_to_stopped_child_used_math(child) \ 1714 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1715 1716 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1717 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1718 #define used_math() tsk_used_math(current) 1719 1720 static __always_inline bool is_percpu_thread(void) 1721 { 1722 #ifdef CONFIG_SMP 1723 return (current->flags & PF_NO_SETAFFINITY) && 1724 (current->nr_cpus_allowed == 1); 1725 #else 1726 return true; 1727 #endif 1728 } 1729 1730 /* Per-process atomic flags. */ 1731 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1732 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1733 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1734 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1735 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1736 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1737 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1738 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1739 1740 #define TASK_PFA_TEST(name, func) \ 1741 static inline bool task_##func(struct task_struct *p) \ 1742 { return test_bit(PFA_##name, &p->atomic_flags); } 1743 1744 #define TASK_PFA_SET(name, func) \ 1745 static inline void task_set_##func(struct task_struct *p) \ 1746 { set_bit(PFA_##name, &p->atomic_flags); } 1747 1748 #define TASK_PFA_CLEAR(name, func) \ 1749 static inline void task_clear_##func(struct task_struct *p) \ 1750 { clear_bit(PFA_##name, &p->atomic_flags); } 1751 1752 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1753 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1754 1755 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1756 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1757 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1758 1759 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1760 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1761 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1762 1763 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1764 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1765 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1766 1767 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1768 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1769 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1770 1771 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1772 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1773 1774 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1775 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1776 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1777 1778 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1779 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1780 1781 static inline void 1782 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1783 { 1784 current->flags &= ~flags; 1785 current->flags |= orig_flags & flags; 1786 } 1787 1788 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1789 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); 1790 #ifdef CONFIG_SMP 1791 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1792 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1793 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1794 extern void release_user_cpus_ptr(struct task_struct *p); 1795 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1796 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1797 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1798 #else 1799 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1800 { 1801 } 1802 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1803 { 1804 if (!cpumask_test_cpu(0, new_mask)) 1805 return -EINVAL; 1806 return 0; 1807 } 1808 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1809 { 1810 if (src->user_cpus_ptr) 1811 return -EINVAL; 1812 return 0; 1813 } 1814 static inline void release_user_cpus_ptr(struct task_struct *p) 1815 { 1816 WARN_ON(p->user_cpus_ptr); 1817 } 1818 1819 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1820 { 1821 return 0; 1822 } 1823 #endif 1824 1825 extern int yield_to(struct task_struct *p, bool preempt); 1826 extern void set_user_nice(struct task_struct *p, long nice); 1827 extern int task_prio(const struct task_struct *p); 1828 1829 /** 1830 * task_nice - return the nice value of a given task. 1831 * @p: the task in question. 1832 * 1833 * Return: The nice value [ -20 ... 0 ... 19 ]. 1834 */ 1835 static inline int task_nice(const struct task_struct *p) 1836 { 1837 return PRIO_TO_NICE((p)->static_prio); 1838 } 1839 1840 extern int can_nice(const struct task_struct *p, const int nice); 1841 extern int task_curr(const struct task_struct *p); 1842 extern int idle_cpu(int cpu); 1843 extern int available_idle_cpu(int cpu); 1844 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1845 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1846 extern void sched_set_fifo(struct task_struct *p); 1847 extern void sched_set_fifo_low(struct task_struct *p); 1848 extern void sched_set_normal(struct task_struct *p, int nice); 1849 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1850 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1851 extern struct task_struct *idle_task(int cpu); 1852 1853 /** 1854 * is_idle_task - is the specified task an idle task? 1855 * @p: the task in question. 1856 * 1857 * Return: 1 if @p is an idle task. 0 otherwise. 1858 */ 1859 static __always_inline bool is_idle_task(const struct task_struct *p) 1860 { 1861 return !!(p->flags & PF_IDLE); 1862 } 1863 1864 extern struct task_struct *curr_task(int cpu); 1865 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1866 1867 void yield(void); 1868 1869 union thread_union { 1870 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1871 struct task_struct task; 1872 #endif 1873 #ifndef CONFIG_THREAD_INFO_IN_TASK 1874 struct thread_info thread_info; 1875 #endif 1876 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1877 }; 1878 1879 #ifndef CONFIG_THREAD_INFO_IN_TASK 1880 extern struct thread_info init_thread_info; 1881 #endif 1882 1883 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1884 1885 #ifdef CONFIG_THREAD_INFO_IN_TASK 1886 # define task_thread_info(task) (&(task)->thread_info) 1887 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1888 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1889 #endif 1890 1891 /* 1892 * find a task by one of its numerical ids 1893 * 1894 * find_task_by_pid_ns(): 1895 * finds a task by its pid in the specified namespace 1896 * find_task_by_vpid(): 1897 * finds a task by its virtual pid 1898 * 1899 * see also find_vpid() etc in include/linux/pid.h 1900 */ 1901 1902 extern struct task_struct *find_task_by_vpid(pid_t nr); 1903 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1904 1905 /* 1906 * find a task by its virtual pid and get the task struct 1907 */ 1908 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1909 1910 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1911 extern int wake_up_process(struct task_struct *tsk); 1912 extern void wake_up_new_task(struct task_struct *tsk); 1913 1914 #ifdef CONFIG_SMP 1915 extern void kick_process(struct task_struct *tsk); 1916 #else 1917 static inline void kick_process(struct task_struct *tsk) { } 1918 #endif 1919 1920 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1921 1922 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1923 { 1924 __set_task_comm(tsk, from, false); 1925 } 1926 1927 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1928 #define get_task_comm(buf, tsk) ({ \ 1929 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1930 __get_task_comm(buf, sizeof(buf), tsk); \ 1931 }) 1932 1933 #ifdef CONFIG_SMP 1934 static __always_inline void scheduler_ipi(void) 1935 { 1936 /* 1937 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1938 * TIF_NEED_RESCHED remotely (for the first time) will also send 1939 * this IPI. 1940 */ 1941 preempt_fold_need_resched(); 1942 } 1943 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1944 #else 1945 static inline void scheduler_ipi(void) { } 1946 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 1947 { 1948 return 1; 1949 } 1950 #endif 1951 1952 /* 1953 * Set thread flags in other task's structures. 1954 * See asm/thread_info.h for TIF_xxxx flags available: 1955 */ 1956 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1957 { 1958 set_ti_thread_flag(task_thread_info(tsk), flag); 1959 } 1960 1961 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1962 { 1963 clear_ti_thread_flag(task_thread_info(tsk), flag); 1964 } 1965 1966 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 1967 bool value) 1968 { 1969 update_ti_thread_flag(task_thread_info(tsk), flag, value); 1970 } 1971 1972 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1973 { 1974 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1975 } 1976 1977 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1978 { 1979 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1980 } 1981 1982 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1983 { 1984 return test_ti_thread_flag(task_thread_info(tsk), flag); 1985 } 1986 1987 static inline void set_tsk_need_resched(struct task_struct *tsk) 1988 { 1989 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1990 } 1991 1992 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1993 { 1994 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1995 } 1996 1997 static inline int test_tsk_need_resched(struct task_struct *tsk) 1998 { 1999 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2000 } 2001 2002 /* 2003 * cond_resched() and cond_resched_lock(): latency reduction via 2004 * explicit rescheduling in places that are safe. The return 2005 * value indicates whether a reschedule was done in fact. 2006 * cond_resched_lock() will drop the spinlock before scheduling, 2007 */ 2008 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2009 extern int __cond_resched(void); 2010 2011 #ifdef CONFIG_PREEMPT_DYNAMIC 2012 2013 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2014 2015 static __always_inline int _cond_resched(void) 2016 { 2017 return static_call_mod(cond_resched)(); 2018 } 2019 2020 #else 2021 2022 static inline int _cond_resched(void) 2023 { 2024 return __cond_resched(); 2025 } 2026 2027 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2028 2029 #else 2030 2031 static inline int _cond_resched(void) { return 0; } 2032 2033 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2034 2035 #define cond_resched() ({ \ 2036 __might_resched(__FILE__, __LINE__, 0); \ 2037 _cond_resched(); \ 2038 }) 2039 2040 extern int __cond_resched_lock(spinlock_t *lock); 2041 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2042 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2043 2044 #define MIGHT_RESCHED_RCU_SHIFT 8 2045 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2046 2047 #ifndef CONFIG_PREEMPT_RT 2048 /* 2049 * Non RT kernels have an elevated preempt count due to the held lock, 2050 * but are not allowed to be inside a RCU read side critical section 2051 */ 2052 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2053 #else 2054 /* 2055 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2056 * cond_resched*lock() has to take that into account because it checks for 2057 * preempt_count() and rcu_preempt_depth(). 2058 */ 2059 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2060 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2061 #endif 2062 2063 #define cond_resched_lock(lock) ({ \ 2064 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2065 __cond_resched_lock(lock); \ 2066 }) 2067 2068 #define cond_resched_rwlock_read(lock) ({ \ 2069 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2070 __cond_resched_rwlock_read(lock); \ 2071 }) 2072 2073 #define cond_resched_rwlock_write(lock) ({ \ 2074 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2075 __cond_resched_rwlock_write(lock); \ 2076 }) 2077 2078 static inline void cond_resched_rcu(void) 2079 { 2080 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2081 rcu_read_unlock(); 2082 cond_resched(); 2083 rcu_read_lock(); 2084 #endif 2085 } 2086 2087 /* 2088 * Does a critical section need to be broken due to another 2089 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2090 * but a general need for low latency) 2091 */ 2092 static inline int spin_needbreak(spinlock_t *lock) 2093 { 2094 #ifdef CONFIG_PREEMPTION 2095 return spin_is_contended(lock); 2096 #else 2097 return 0; 2098 #endif 2099 } 2100 2101 /* 2102 * Check if a rwlock is contended. 2103 * Returns non-zero if there is another task waiting on the rwlock. 2104 * Returns zero if the lock is not contended or the system / underlying 2105 * rwlock implementation does not support contention detection. 2106 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2107 * for low latency. 2108 */ 2109 static inline int rwlock_needbreak(rwlock_t *lock) 2110 { 2111 #ifdef CONFIG_PREEMPTION 2112 return rwlock_is_contended(lock); 2113 #else 2114 return 0; 2115 #endif 2116 } 2117 2118 static __always_inline bool need_resched(void) 2119 { 2120 return unlikely(tif_need_resched()); 2121 } 2122 2123 /* 2124 * Wrappers for p->thread_info->cpu access. No-op on UP. 2125 */ 2126 #ifdef CONFIG_SMP 2127 2128 static inline unsigned int task_cpu(const struct task_struct *p) 2129 { 2130 return READ_ONCE(task_thread_info(p)->cpu); 2131 } 2132 2133 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2134 2135 #else 2136 2137 static inline unsigned int task_cpu(const struct task_struct *p) 2138 { 2139 return 0; 2140 } 2141 2142 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2143 { 2144 } 2145 2146 #endif /* CONFIG_SMP */ 2147 2148 extern bool sched_task_on_rq(struct task_struct *p); 2149 extern unsigned long get_wchan(struct task_struct *p); 2150 2151 /* 2152 * In order to reduce various lock holder preemption latencies provide an 2153 * interface to see if a vCPU is currently running or not. 2154 * 2155 * This allows us to terminate optimistic spin loops and block, analogous to 2156 * the native optimistic spin heuristic of testing if the lock owner task is 2157 * running or not. 2158 */ 2159 #ifndef vcpu_is_preempted 2160 static inline bool vcpu_is_preempted(int cpu) 2161 { 2162 return false; 2163 } 2164 #endif 2165 2166 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2167 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2168 2169 #ifndef TASK_SIZE_OF 2170 #define TASK_SIZE_OF(tsk) TASK_SIZE 2171 #endif 2172 2173 #ifdef CONFIG_SMP 2174 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2175 unsigned long sched_cpu_util(int cpu, unsigned long max); 2176 #endif /* CONFIG_SMP */ 2177 2178 #ifdef CONFIG_RSEQ 2179 2180 /* 2181 * Map the event mask on the user-space ABI enum rseq_cs_flags 2182 * for direct mask checks. 2183 */ 2184 enum rseq_event_mask_bits { 2185 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2186 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2187 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2188 }; 2189 2190 enum rseq_event_mask { 2191 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2192 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2193 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2194 }; 2195 2196 static inline void rseq_set_notify_resume(struct task_struct *t) 2197 { 2198 if (t->rseq) 2199 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2200 } 2201 2202 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2203 2204 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2205 struct pt_regs *regs) 2206 { 2207 if (current->rseq) 2208 __rseq_handle_notify_resume(ksig, regs); 2209 } 2210 2211 static inline void rseq_signal_deliver(struct ksignal *ksig, 2212 struct pt_regs *regs) 2213 { 2214 preempt_disable(); 2215 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2216 preempt_enable(); 2217 rseq_handle_notify_resume(ksig, regs); 2218 } 2219 2220 /* rseq_preempt() requires preemption to be disabled. */ 2221 static inline void rseq_preempt(struct task_struct *t) 2222 { 2223 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2224 rseq_set_notify_resume(t); 2225 } 2226 2227 /* rseq_migrate() requires preemption to be disabled. */ 2228 static inline void rseq_migrate(struct task_struct *t) 2229 { 2230 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2231 rseq_set_notify_resume(t); 2232 } 2233 2234 /* 2235 * If parent process has a registered restartable sequences area, the 2236 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2237 */ 2238 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2239 { 2240 if (clone_flags & CLONE_VM) { 2241 t->rseq = NULL; 2242 t->rseq_sig = 0; 2243 t->rseq_event_mask = 0; 2244 } else { 2245 t->rseq = current->rseq; 2246 t->rseq_sig = current->rseq_sig; 2247 t->rseq_event_mask = current->rseq_event_mask; 2248 } 2249 } 2250 2251 static inline void rseq_execve(struct task_struct *t) 2252 { 2253 t->rseq = NULL; 2254 t->rseq_sig = 0; 2255 t->rseq_event_mask = 0; 2256 } 2257 2258 #else 2259 2260 static inline void rseq_set_notify_resume(struct task_struct *t) 2261 { 2262 } 2263 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2264 struct pt_regs *regs) 2265 { 2266 } 2267 static inline void rseq_signal_deliver(struct ksignal *ksig, 2268 struct pt_regs *regs) 2269 { 2270 } 2271 static inline void rseq_preempt(struct task_struct *t) 2272 { 2273 } 2274 static inline void rseq_migrate(struct task_struct *t) 2275 { 2276 } 2277 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2278 { 2279 } 2280 static inline void rseq_execve(struct task_struct *t) 2281 { 2282 } 2283 2284 #endif 2285 2286 #ifdef CONFIG_DEBUG_RSEQ 2287 2288 void rseq_syscall(struct pt_regs *regs); 2289 2290 #else 2291 2292 static inline void rseq_syscall(struct pt_regs *regs) 2293 { 2294 } 2295 2296 #endif 2297 2298 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq); 2299 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len); 2300 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq); 2301 2302 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq); 2303 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq); 2304 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq); 2305 2306 int sched_trace_rq_cpu(struct rq *rq); 2307 int sched_trace_rq_cpu_capacity(struct rq *rq); 2308 int sched_trace_rq_nr_running(struct rq *rq); 2309 2310 const struct cpumask *sched_trace_rd_span(struct root_domain *rd); 2311 2312 #ifdef CONFIG_SCHED_CORE 2313 extern void sched_core_free(struct task_struct *tsk); 2314 extern void sched_core_fork(struct task_struct *p); 2315 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2316 unsigned long uaddr); 2317 #else 2318 static inline void sched_core_free(struct task_struct *tsk) { } 2319 static inline void sched_core_fork(struct task_struct *p) { } 2320 #endif 2321 2322 #endif 2323