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 u64 exec_max; 507 u64 slice_max; 508 509 u64 nr_migrations_cold; 510 u64 nr_failed_migrations_affine; 511 u64 nr_failed_migrations_running; 512 u64 nr_failed_migrations_hot; 513 u64 nr_forced_migrations; 514 515 u64 nr_wakeups; 516 u64 nr_wakeups_sync; 517 u64 nr_wakeups_migrate; 518 u64 nr_wakeups_local; 519 u64 nr_wakeups_remote; 520 u64 nr_wakeups_affine; 521 u64 nr_wakeups_affine_attempts; 522 u64 nr_wakeups_passive; 523 u64 nr_wakeups_idle; 524 #endif 525 }; 526 527 struct sched_entity { 528 /* For load-balancing: */ 529 struct load_weight load; 530 struct rb_node run_node; 531 struct list_head group_node; 532 unsigned int on_rq; 533 534 u64 exec_start; 535 u64 sum_exec_runtime; 536 u64 vruntime; 537 u64 prev_sum_exec_runtime; 538 539 u64 nr_migrations; 540 541 struct sched_statistics statistics; 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 #ifdef CONFIG_THREAD_INFO_IN_TASK 754 /* Current CPU: */ 755 unsigned int cpu; 756 #endif 757 unsigned int wakee_flips; 758 unsigned long wakee_flip_decay_ts; 759 struct task_struct *last_wakee; 760 761 /* 762 * recent_used_cpu is initially set as the last CPU used by a task 763 * that wakes affine another task. Waker/wakee relationships can 764 * push tasks around a CPU where each wakeup moves to the next one. 765 * Tracking a recently used CPU allows a quick search for a recently 766 * used CPU that may be idle. 767 */ 768 int recent_used_cpu; 769 int wake_cpu; 770 #endif 771 int on_rq; 772 773 int prio; 774 int static_prio; 775 int normal_prio; 776 unsigned int rt_priority; 777 778 const struct sched_class *sched_class; 779 struct sched_entity se; 780 struct sched_rt_entity rt; 781 struct sched_dl_entity dl; 782 783 #ifdef CONFIG_SCHED_CORE 784 struct rb_node core_node; 785 unsigned long core_cookie; 786 unsigned int core_occupation; 787 #endif 788 789 #ifdef CONFIG_CGROUP_SCHED 790 struct task_group *sched_task_group; 791 #endif 792 793 #ifdef CONFIG_UCLAMP_TASK 794 /* 795 * Clamp values requested for a scheduling entity. 796 * Must be updated with task_rq_lock() held. 797 */ 798 struct uclamp_se uclamp_req[UCLAMP_CNT]; 799 /* 800 * Effective clamp values used for a scheduling entity. 801 * Must be updated with task_rq_lock() held. 802 */ 803 struct uclamp_se uclamp[UCLAMP_CNT]; 804 #endif 805 806 #ifdef CONFIG_PREEMPT_NOTIFIERS 807 /* List of struct preempt_notifier: */ 808 struct hlist_head preempt_notifiers; 809 #endif 810 811 #ifdef CONFIG_BLK_DEV_IO_TRACE 812 unsigned int btrace_seq; 813 #endif 814 815 unsigned int policy; 816 int nr_cpus_allowed; 817 const cpumask_t *cpus_ptr; 818 cpumask_t *user_cpus_ptr; 819 cpumask_t cpus_mask; 820 void *migration_pending; 821 #ifdef CONFIG_SMP 822 unsigned short migration_disabled; 823 #endif 824 unsigned short migration_flags; 825 826 #ifdef CONFIG_PREEMPT_RCU 827 int rcu_read_lock_nesting; 828 union rcu_special rcu_read_unlock_special; 829 struct list_head rcu_node_entry; 830 struct rcu_node *rcu_blocked_node; 831 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 832 833 #ifdef CONFIG_TASKS_RCU 834 unsigned long rcu_tasks_nvcsw; 835 u8 rcu_tasks_holdout; 836 u8 rcu_tasks_idx; 837 int rcu_tasks_idle_cpu; 838 struct list_head rcu_tasks_holdout_list; 839 #endif /* #ifdef CONFIG_TASKS_RCU */ 840 841 #ifdef CONFIG_TASKS_TRACE_RCU 842 int trc_reader_nesting; 843 int trc_ipi_to_cpu; 844 union rcu_special trc_reader_special; 845 bool trc_reader_checked; 846 struct list_head trc_holdout_list; 847 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 848 849 struct sched_info sched_info; 850 851 struct list_head tasks; 852 #ifdef CONFIG_SMP 853 struct plist_node pushable_tasks; 854 struct rb_node pushable_dl_tasks; 855 #endif 856 857 struct mm_struct *mm; 858 struct mm_struct *active_mm; 859 860 /* Per-thread vma caching: */ 861 struct vmacache vmacache; 862 863 #ifdef SPLIT_RSS_COUNTING 864 struct task_rss_stat rss_stat; 865 #endif 866 int exit_state; 867 int exit_code; 868 int exit_signal; 869 /* The signal sent when the parent dies: */ 870 int pdeath_signal; 871 /* JOBCTL_*, siglock protected: */ 872 unsigned long jobctl; 873 874 /* Used for emulating ABI behavior of previous Linux versions: */ 875 unsigned int personality; 876 877 /* Scheduler bits, serialized by scheduler locks: */ 878 unsigned sched_reset_on_fork:1; 879 unsigned sched_contributes_to_load:1; 880 unsigned sched_migrated:1; 881 #ifdef CONFIG_PSI 882 unsigned sched_psi_wake_requeue:1; 883 #endif 884 885 /* Force alignment to the next boundary: */ 886 unsigned :0; 887 888 /* Unserialized, strictly 'current' */ 889 890 /* 891 * This field must not be in the scheduler word above due to wakelist 892 * queueing no longer being serialized by p->on_cpu. However: 893 * 894 * p->XXX = X; ttwu() 895 * schedule() if (p->on_rq && ..) // false 896 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 897 * deactivate_task() ttwu_queue_wakelist()) 898 * p->on_rq = 0; p->sched_remote_wakeup = Y; 899 * 900 * guarantees all stores of 'current' are visible before 901 * ->sched_remote_wakeup gets used, so it can be in this word. 902 */ 903 unsigned sched_remote_wakeup:1; 904 905 /* Bit to tell LSMs we're in execve(): */ 906 unsigned in_execve:1; 907 unsigned in_iowait:1; 908 #ifndef TIF_RESTORE_SIGMASK 909 unsigned restore_sigmask:1; 910 #endif 911 #ifdef CONFIG_MEMCG 912 unsigned in_user_fault:1; 913 #endif 914 #ifdef CONFIG_COMPAT_BRK 915 unsigned brk_randomized:1; 916 #endif 917 #ifdef CONFIG_CGROUPS 918 /* disallow userland-initiated cgroup migration */ 919 unsigned no_cgroup_migration:1; 920 /* task is frozen/stopped (used by the cgroup freezer) */ 921 unsigned frozen:1; 922 #endif 923 #ifdef CONFIG_BLK_CGROUP 924 unsigned use_memdelay:1; 925 #endif 926 #ifdef CONFIG_PSI 927 /* Stalled due to lack of memory */ 928 unsigned in_memstall:1; 929 #endif 930 #ifdef CONFIG_PAGE_OWNER 931 /* Used by page_owner=on to detect recursion in page tracking. */ 932 unsigned in_page_owner:1; 933 #endif 934 #ifdef CONFIG_EVENTFD 935 /* Recursion prevention for eventfd_signal() */ 936 unsigned in_eventfd_signal:1; 937 #endif 938 939 unsigned long atomic_flags; /* Flags requiring atomic access. */ 940 941 struct restart_block restart_block; 942 943 pid_t pid; 944 pid_t tgid; 945 946 #ifdef CONFIG_STACKPROTECTOR 947 /* Canary value for the -fstack-protector GCC feature: */ 948 unsigned long stack_canary; 949 #endif 950 /* 951 * Pointers to the (original) parent process, youngest child, younger sibling, 952 * older sibling, respectively. (p->father can be replaced with 953 * p->real_parent->pid) 954 */ 955 956 /* Real parent process: */ 957 struct task_struct __rcu *real_parent; 958 959 /* Recipient of SIGCHLD, wait4() reports: */ 960 struct task_struct __rcu *parent; 961 962 /* 963 * Children/sibling form the list of natural children: 964 */ 965 struct list_head children; 966 struct list_head sibling; 967 struct task_struct *group_leader; 968 969 /* 970 * 'ptraced' is the list of tasks this task is using ptrace() on. 971 * 972 * This includes both natural children and PTRACE_ATTACH targets. 973 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 974 */ 975 struct list_head ptraced; 976 struct list_head ptrace_entry; 977 978 /* PID/PID hash table linkage. */ 979 struct pid *thread_pid; 980 struct hlist_node pid_links[PIDTYPE_MAX]; 981 struct list_head thread_group; 982 struct list_head thread_node; 983 984 struct completion *vfork_done; 985 986 /* CLONE_CHILD_SETTID: */ 987 int __user *set_child_tid; 988 989 /* CLONE_CHILD_CLEARTID: */ 990 int __user *clear_child_tid; 991 992 /* PF_IO_WORKER */ 993 void *pf_io_worker; 994 995 u64 utime; 996 u64 stime; 997 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 998 u64 utimescaled; 999 u64 stimescaled; 1000 #endif 1001 u64 gtime; 1002 struct prev_cputime prev_cputime; 1003 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1004 struct vtime vtime; 1005 #endif 1006 1007 #ifdef CONFIG_NO_HZ_FULL 1008 atomic_t tick_dep_mask; 1009 #endif 1010 /* Context switch counts: */ 1011 unsigned long nvcsw; 1012 unsigned long nivcsw; 1013 1014 /* Monotonic time in nsecs: */ 1015 u64 start_time; 1016 1017 /* Boot based time in nsecs: */ 1018 u64 start_boottime; 1019 1020 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1021 unsigned long min_flt; 1022 unsigned long maj_flt; 1023 1024 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1025 struct posix_cputimers posix_cputimers; 1026 1027 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1028 struct posix_cputimers_work posix_cputimers_work; 1029 #endif 1030 1031 /* Process credentials: */ 1032 1033 /* Tracer's credentials at attach: */ 1034 const struct cred __rcu *ptracer_cred; 1035 1036 /* Objective and real subjective task credentials (COW): */ 1037 const struct cred __rcu *real_cred; 1038 1039 /* Effective (overridable) subjective task credentials (COW): */ 1040 const struct cred __rcu *cred; 1041 1042 #ifdef CONFIG_KEYS 1043 /* Cached requested key. */ 1044 struct key *cached_requested_key; 1045 #endif 1046 1047 /* 1048 * executable name, excluding path. 1049 * 1050 * - normally initialized setup_new_exec() 1051 * - access it with [gs]et_task_comm() 1052 * - lock it with task_lock() 1053 */ 1054 char comm[TASK_COMM_LEN]; 1055 1056 struct nameidata *nameidata; 1057 1058 #ifdef CONFIG_SYSVIPC 1059 struct sysv_sem sysvsem; 1060 struct sysv_shm sysvshm; 1061 #endif 1062 #ifdef CONFIG_DETECT_HUNG_TASK 1063 unsigned long last_switch_count; 1064 unsigned long last_switch_time; 1065 #endif 1066 /* Filesystem information: */ 1067 struct fs_struct *fs; 1068 1069 /* Open file information: */ 1070 struct files_struct *files; 1071 1072 #ifdef CONFIG_IO_URING 1073 struct io_uring_task *io_uring; 1074 #endif 1075 1076 /* Namespaces: */ 1077 struct nsproxy *nsproxy; 1078 1079 /* Signal handlers: */ 1080 struct signal_struct *signal; 1081 struct sighand_struct __rcu *sighand; 1082 sigset_t blocked; 1083 sigset_t real_blocked; 1084 /* Restored if set_restore_sigmask() was used: */ 1085 sigset_t saved_sigmask; 1086 struct sigpending pending; 1087 unsigned long sas_ss_sp; 1088 size_t sas_ss_size; 1089 unsigned int sas_ss_flags; 1090 1091 struct callback_head *task_works; 1092 1093 #ifdef CONFIG_AUDIT 1094 #ifdef CONFIG_AUDITSYSCALL 1095 struct audit_context *audit_context; 1096 #endif 1097 kuid_t loginuid; 1098 unsigned int sessionid; 1099 #endif 1100 struct seccomp seccomp; 1101 struct syscall_user_dispatch syscall_dispatch; 1102 1103 /* Thread group tracking: */ 1104 u64 parent_exec_id; 1105 u64 self_exec_id; 1106 1107 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1108 spinlock_t alloc_lock; 1109 1110 /* Protection of the PI data structures: */ 1111 raw_spinlock_t pi_lock; 1112 1113 struct wake_q_node wake_q; 1114 1115 #ifdef CONFIG_RT_MUTEXES 1116 /* PI waiters blocked on a rt_mutex held by this task: */ 1117 struct rb_root_cached pi_waiters; 1118 /* Updated under owner's pi_lock and rq lock */ 1119 struct task_struct *pi_top_task; 1120 /* Deadlock detection and priority inheritance handling: */ 1121 struct rt_mutex_waiter *pi_blocked_on; 1122 #endif 1123 1124 #ifdef CONFIG_DEBUG_MUTEXES 1125 /* Mutex deadlock detection: */ 1126 struct mutex_waiter *blocked_on; 1127 #endif 1128 1129 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1130 int non_block_count; 1131 #endif 1132 1133 #ifdef CONFIG_TRACE_IRQFLAGS 1134 struct irqtrace_events irqtrace; 1135 unsigned int hardirq_threaded; 1136 u64 hardirq_chain_key; 1137 int softirqs_enabled; 1138 int softirq_context; 1139 int irq_config; 1140 #endif 1141 #ifdef CONFIG_PREEMPT_RT 1142 int softirq_disable_cnt; 1143 #endif 1144 1145 #ifdef CONFIG_LOCKDEP 1146 # define MAX_LOCK_DEPTH 48UL 1147 u64 curr_chain_key; 1148 int lockdep_depth; 1149 unsigned int lockdep_recursion; 1150 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1151 #endif 1152 1153 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1154 unsigned int in_ubsan; 1155 #endif 1156 1157 /* Journalling filesystem info: */ 1158 void *journal_info; 1159 1160 /* Stacked block device info: */ 1161 struct bio_list *bio_list; 1162 1163 #ifdef CONFIG_BLOCK 1164 /* Stack plugging: */ 1165 struct blk_plug *plug; 1166 #endif 1167 1168 /* VM state: */ 1169 struct reclaim_state *reclaim_state; 1170 1171 struct backing_dev_info *backing_dev_info; 1172 1173 struct io_context *io_context; 1174 1175 #ifdef CONFIG_COMPACTION 1176 struct capture_control *capture_control; 1177 #endif 1178 /* Ptrace state: */ 1179 unsigned long ptrace_message; 1180 kernel_siginfo_t *last_siginfo; 1181 1182 struct task_io_accounting ioac; 1183 #ifdef CONFIG_PSI 1184 /* Pressure stall state */ 1185 unsigned int psi_flags; 1186 #endif 1187 #ifdef CONFIG_TASK_XACCT 1188 /* Accumulated RSS usage: */ 1189 u64 acct_rss_mem1; 1190 /* Accumulated virtual memory usage: */ 1191 u64 acct_vm_mem1; 1192 /* stime + utime since last update: */ 1193 u64 acct_timexpd; 1194 #endif 1195 #ifdef CONFIG_CPUSETS 1196 /* Protected by ->alloc_lock: */ 1197 nodemask_t mems_allowed; 1198 /* Sequence number to catch updates: */ 1199 seqcount_spinlock_t mems_allowed_seq; 1200 int cpuset_mem_spread_rotor; 1201 int cpuset_slab_spread_rotor; 1202 #endif 1203 #ifdef CONFIG_CGROUPS 1204 /* Control Group info protected by css_set_lock: */ 1205 struct css_set __rcu *cgroups; 1206 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1207 struct list_head cg_list; 1208 #endif 1209 #ifdef CONFIG_X86_CPU_RESCTRL 1210 u32 closid; 1211 u32 rmid; 1212 #endif 1213 #ifdef CONFIG_FUTEX 1214 struct robust_list_head __user *robust_list; 1215 #ifdef CONFIG_COMPAT 1216 struct compat_robust_list_head __user *compat_robust_list; 1217 #endif 1218 struct list_head pi_state_list; 1219 struct futex_pi_state *pi_state_cache; 1220 struct mutex futex_exit_mutex; 1221 unsigned int futex_state; 1222 #endif 1223 #ifdef CONFIG_PERF_EVENTS 1224 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 1225 struct mutex perf_event_mutex; 1226 struct list_head perf_event_list; 1227 #endif 1228 #ifdef CONFIG_DEBUG_PREEMPT 1229 unsigned long preempt_disable_ip; 1230 #endif 1231 #ifdef CONFIG_NUMA 1232 /* Protected by alloc_lock: */ 1233 struct mempolicy *mempolicy; 1234 short il_prev; 1235 short pref_node_fork; 1236 #endif 1237 #ifdef CONFIG_NUMA_BALANCING 1238 int numa_scan_seq; 1239 unsigned int numa_scan_period; 1240 unsigned int numa_scan_period_max; 1241 int numa_preferred_nid; 1242 unsigned long numa_migrate_retry; 1243 /* Migration stamp: */ 1244 u64 node_stamp; 1245 u64 last_task_numa_placement; 1246 u64 last_sum_exec_runtime; 1247 struct callback_head numa_work; 1248 1249 /* 1250 * This pointer is only modified for current in syscall and 1251 * pagefault context (and for tasks being destroyed), so it can be read 1252 * from any of the following contexts: 1253 * - RCU read-side critical section 1254 * - current->numa_group from everywhere 1255 * - task's runqueue locked, task not running 1256 */ 1257 struct numa_group __rcu *numa_group; 1258 1259 /* 1260 * numa_faults is an array split into four regions: 1261 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1262 * in this precise order. 1263 * 1264 * faults_memory: Exponential decaying average of faults on a per-node 1265 * basis. Scheduling placement decisions are made based on these 1266 * counts. The values remain static for the duration of a PTE scan. 1267 * faults_cpu: Track the nodes the process was running on when a NUMA 1268 * hinting fault was incurred. 1269 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1270 * during the current scan window. When the scan completes, the counts 1271 * in faults_memory and faults_cpu decay and these values are copied. 1272 */ 1273 unsigned long *numa_faults; 1274 unsigned long total_numa_faults; 1275 1276 /* 1277 * numa_faults_locality tracks if faults recorded during the last 1278 * scan window were remote/local or failed to migrate. The task scan 1279 * period is adapted based on the locality of the faults with different 1280 * weights depending on whether they were shared or private faults 1281 */ 1282 unsigned long numa_faults_locality[3]; 1283 1284 unsigned long numa_pages_migrated; 1285 #endif /* CONFIG_NUMA_BALANCING */ 1286 1287 #ifdef CONFIG_RSEQ 1288 struct rseq __user *rseq; 1289 u32 rseq_sig; 1290 /* 1291 * RmW on rseq_event_mask must be performed atomically 1292 * with respect to preemption. 1293 */ 1294 unsigned long rseq_event_mask; 1295 #endif 1296 1297 struct tlbflush_unmap_batch tlb_ubc; 1298 1299 union { 1300 refcount_t rcu_users; 1301 struct rcu_head rcu; 1302 }; 1303 1304 /* Cache last used pipe for splice(): */ 1305 struct pipe_inode_info *splice_pipe; 1306 1307 struct page_frag task_frag; 1308 1309 #ifdef CONFIG_TASK_DELAY_ACCT 1310 struct task_delay_info *delays; 1311 #endif 1312 1313 #ifdef CONFIG_FAULT_INJECTION 1314 int make_it_fail; 1315 unsigned int fail_nth; 1316 #endif 1317 /* 1318 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1319 * balance_dirty_pages() for a dirty throttling pause: 1320 */ 1321 int nr_dirtied; 1322 int nr_dirtied_pause; 1323 /* Start of a write-and-pause period: */ 1324 unsigned long dirty_paused_when; 1325 1326 #ifdef CONFIG_LATENCYTOP 1327 int latency_record_count; 1328 struct latency_record latency_record[LT_SAVECOUNT]; 1329 #endif 1330 /* 1331 * Time slack values; these are used to round up poll() and 1332 * select() etc timeout values. These are in nanoseconds. 1333 */ 1334 u64 timer_slack_ns; 1335 u64 default_timer_slack_ns; 1336 1337 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1338 unsigned int kasan_depth; 1339 #endif 1340 1341 #ifdef CONFIG_KCSAN 1342 struct kcsan_ctx kcsan_ctx; 1343 #ifdef CONFIG_TRACE_IRQFLAGS 1344 struct irqtrace_events kcsan_save_irqtrace; 1345 #endif 1346 #endif 1347 1348 #if IS_ENABLED(CONFIG_KUNIT) 1349 struct kunit *kunit_test; 1350 #endif 1351 1352 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1353 /* Index of current stored address in ret_stack: */ 1354 int curr_ret_stack; 1355 int curr_ret_depth; 1356 1357 /* Stack of return addresses for return function tracing: */ 1358 struct ftrace_ret_stack *ret_stack; 1359 1360 /* Timestamp for last schedule: */ 1361 unsigned long long ftrace_timestamp; 1362 1363 /* 1364 * Number of functions that haven't been traced 1365 * because of depth overrun: 1366 */ 1367 atomic_t trace_overrun; 1368 1369 /* Pause tracing: */ 1370 atomic_t tracing_graph_pause; 1371 #endif 1372 1373 #ifdef CONFIG_TRACING 1374 /* State flags for use by tracers: */ 1375 unsigned long trace; 1376 1377 /* Bitmask and counter of trace recursion: */ 1378 unsigned long trace_recursion; 1379 #endif /* CONFIG_TRACING */ 1380 1381 #ifdef CONFIG_KCOV 1382 /* See kernel/kcov.c for more details. */ 1383 1384 /* Coverage collection mode enabled for this task (0 if disabled): */ 1385 unsigned int kcov_mode; 1386 1387 /* Size of the kcov_area: */ 1388 unsigned int kcov_size; 1389 1390 /* Buffer for coverage collection: */ 1391 void *kcov_area; 1392 1393 /* KCOV descriptor wired with this task or NULL: */ 1394 struct kcov *kcov; 1395 1396 /* KCOV common handle for remote coverage collection: */ 1397 u64 kcov_handle; 1398 1399 /* KCOV sequence number: */ 1400 int kcov_sequence; 1401 1402 /* Collect coverage from softirq context: */ 1403 unsigned int kcov_softirq; 1404 #endif 1405 1406 #ifdef CONFIG_MEMCG 1407 struct mem_cgroup *memcg_in_oom; 1408 gfp_t memcg_oom_gfp_mask; 1409 int memcg_oom_order; 1410 1411 /* Number of pages to reclaim on returning to userland: */ 1412 unsigned int memcg_nr_pages_over_high; 1413 1414 /* Used by memcontrol for targeted memcg charge: */ 1415 struct mem_cgroup *active_memcg; 1416 #endif 1417 1418 #ifdef CONFIG_BLK_CGROUP 1419 struct request_queue *throttle_queue; 1420 #endif 1421 1422 #ifdef CONFIG_UPROBES 1423 struct uprobe_task *utask; 1424 #endif 1425 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1426 unsigned int sequential_io; 1427 unsigned int sequential_io_avg; 1428 #endif 1429 struct kmap_ctrl kmap_ctrl; 1430 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1431 unsigned long task_state_change; 1432 # ifdef CONFIG_PREEMPT_RT 1433 unsigned long saved_state_change; 1434 # endif 1435 #endif 1436 int pagefault_disabled; 1437 #ifdef CONFIG_MMU 1438 struct task_struct *oom_reaper_list; 1439 #endif 1440 #ifdef CONFIG_VMAP_STACK 1441 struct vm_struct *stack_vm_area; 1442 #endif 1443 #ifdef CONFIG_THREAD_INFO_IN_TASK 1444 /* A live task holds one reference: */ 1445 refcount_t stack_refcount; 1446 #endif 1447 #ifdef CONFIG_LIVEPATCH 1448 int patch_state; 1449 #endif 1450 #ifdef CONFIG_SECURITY 1451 /* Used by LSM modules for access restriction: */ 1452 void *security; 1453 #endif 1454 #ifdef CONFIG_BPF_SYSCALL 1455 /* Used by BPF task local storage */ 1456 struct bpf_local_storage __rcu *bpf_storage; 1457 /* Used for BPF run context */ 1458 struct bpf_run_ctx *bpf_ctx; 1459 #endif 1460 1461 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1462 unsigned long lowest_stack; 1463 unsigned long prev_lowest_stack; 1464 #endif 1465 1466 #ifdef CONFIG_X86_MCE 1467 void __user *mce_vaddr; 1468 __u64 mce_kflags; 1469 u64 mce_addr; 1470 __u64 mce_ripv : 1, 1471 mce_whole_page : 1, 1472 __mce_reserved : 62; 1473 struct callback_head mce_kill_me; 1474 int mce_count; 1475 #endif 1476 1477 #ifdef CONFIG_KRETPROBES 1478 struct llist_head kretprobe_instances; 1479 #endif 1480 1481 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1482 /* 1483 * If L1D flush is supported on mm context switch 1484 * then we use this callback head to queue kill work 1485 * to kill tasks that are not running on SMT disabled 1486 * cores 1487 */ 1488 struct callback_head l1d_flush_kill; 1489 #endif 1490 1491 /* 1492 * New fields for task_struct should be added above here, so that 1493 * they are included in the randomized portion of task_struct. 1494 */ 1495 randomized_struct_fields_end 1496 1497 /* CPU-specific state of this task: */ 1498 struct thread_struct thread; 1499 1500 /* 1501 * WARNING: on x86, 'thread_struct' contains a variable-sized 1502 * structure. It *MUST* be at the end of 'task_struct'. 1503 * 1504 * Do not put anything below here! 1505 */ 1506 }; 1507 1508 static inline struct pid *task_pid(struct task_struct *task) 1509 { 1510 return task->thread_pid; 1511 } 1512 1513 /* 1514 * the helpers to get the task's different pids as they are seen 1515 * from various namespaces 1516 * 1517 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1518 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1519 * current. 1520 * task_xid_nr_ns() : id seen from the ns specified; 1521 * 1522 * see also pid_nr() etc in include/linux/pid.h 1523 */ 1524 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1525 1526 static inline pid_t task_pid_nr(struct task_struct *tsk) 1527 { 1528 return tsk->pid; 1529 } 1530 1531 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1532 { 1533 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1534 } 1535 1536 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1537 { 1538 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1539 } 1540 1541 1542 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1543 { 1544 return tsk->tgid; 1545 } 1546 1547 /** 1548 * pid_alive - check that a task structure is not stale 1549 * @p: Task structure to be checked. 1550 * 1551 * Test if a process is not yet dead (at most zombie state) 1552 * If pid_alive fails, then pointers within the task structure 1553 * can be stale and must not be dereferenced. 1554 * 1555 * Return: 1 if the process is alive. 0 otherwise. 1556 */ 1557 static inline int pid_alive(const struct task_struct *p) 1558 { 1559 return p->thread_pid != NULL; 1560 } 1561 1562 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1563 { 1564 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1565 } 1566 1567 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1568 { 1569 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1570 } 1571 1572 1573 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1574 { 1575 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1576 } 1577 1578 static inline pid_t task_session_vnr(struct task_struct *tsk) 1579 { 1580 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1581 } 1582 1583 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1584 { 1585 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1586 } 1587 1588 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1589 { 1590 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1591 } 1592 1593 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1594 { 1595 pid_t pid = 0; 1596 1597 rcu_read_lock(); 1598 if (pid_alive(tsk)) 1599 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1600 rcu_read_unlock(); 1601 1602 return pid; 1603 } 1604 1605 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1606 { 1607 return task_ppid_nr_ns(tsk, &init_pid_ns); 1608 } 1609 1610 /* Obsolete, do not use: */ 1611 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1612 { 1613 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1614 } 1615 1616 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1617 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1618 1619 static inline unsigned int task_state_index(struct task_struct *tsk) 1620 { 1621 unsigned int tsk_state = READ_ONCE(tsk->__state); 1622 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT; 1623 1624 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1625 1626 if (tsk_state == TASK_IDLE) 1627 state = TASK_REPORT_IDLE; 1628 1629 return fls(state); 1630 } 1631 1632 static inline char task_index_to_char(unsigned int state) 1633 { 1634 static const char state_char[] = "RSDTtXZPI"; 1635 1636 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1637 1638 return state_char[state]; 1639 } 1640 1641 static inline char task_state_to_char(struct task_struct *tsk) 1642 { 1643 return task_index_to_char(task_state_index(tsk)); 1644 } 1645 1646 /** 1647 * is_global_init - check if a task structure is init. Since init 1648 * is free to have sub-threads we need to check tgid. 1649 * @tsk: Task structure to be checked. 1650 * 1651 * Check if a task structure is the first user space task the kernel created. 1652 * 1653 * Return: 1 if the task structure is init. 0 otherwise. 1654 */ 1655 static inline int is_global_init(struct task_struct *tsk) 1656 { 1657 return task_tgid_nr(tsk) == 1; 1658 } 1659 1660 extern struct pid *cad_pid; 1661 1662 /* 1663 * Per process flags 1664 */ 1665 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1666 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1667 #define PF_EXITING 0x00000004 /* Getting shut down */ 1668 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1669 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1670 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1671 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1672 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1673 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1674 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1675 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1676 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1677 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1678 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */ 1679 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1680 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1681 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1682 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1683 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1684 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1685 * I am cleaning dirty pages from some other bdi. */ 1686 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1687 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1688 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ 1689 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1690 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1691 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1692 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1693 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1694 1695 /* 1696 * Only the _current_ task can read/write to tsk->flags, but other 1697 * tasks can access tsk->flags in readonly mode for example 1698 * with tsk_used_math (like during threaded core dumping). 1699 * There is however an exception to this rule during ptrace 1700 * or during fork: the ptracer task is allowed to write to the 1701 * child->flags of its traced child (same goes for fork, the parent 1702 * can write to the child->flags), because we're guaranteed the 1703 * child is not running and in turn not changing child->flags 1704 * at the same time the parent does it. 1705 */ 1706 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1707 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1708 #define clear_used_math() clear_stopped_child_used_math(current) 1709 #define set_used_math() set_stopped_child_used_math(current) 1710 1711 #define conditional_stopped_child_used_math(condition, child) \ 1712 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1713 1714 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1715 1716 #define copy_to_stopped_child_used_math(child) \ 1717 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1718 1719 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1720 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1721 #define used_math() tsk_used_math(current) 1722 1723 static inline bool is_percpu_thread(void) 1724 { 1725 #ifdef CONFIG_SMP 1726 return (current->flags & PF_NO_SETAFFINITY) && 1727 (current->nr_cpus_allowed == 1); 1728 #else 1729 return true; 1730 #endif 1731 } 1732 1733 /* Per-process atomic flags. */ 1734 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1735 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1736 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1737 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1738 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1739 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1740 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1741 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1742 1743 #define TASK_PFA_TEST(name, func) \ 1744 static inline bool task_##func(struct task_struct *p) \ 1745 { return test_bit(PFA_##name, &p->atomic_flags); } 1746 1747 #define TASK_PFA_SET(name, func) \ 1748 static inline void task_set_##func(struct task_struct *p) \ 1749 { set_bit(PFA_##name, &p->atomic_flags); } 1750 1751 #define TASK_PFA_CLEAR(name, func) \ 1752 static inline void task_clear_##func(struct task_struct *p) \ 1753 { clear_bit(PFA_##name, &p->atomic_flags); } 1754 1755 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1756 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1757 1758 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1759 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1760 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1761 1762 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1763 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1764 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1765 1766 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1767 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1768 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1769 1770 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1771 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1772 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1773 1774 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1775 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1776 1777 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1778 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1779 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1780 1781 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1782 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1783 1784 static inline void 1785 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1786 { 1787 current->flags &= ~flags; 1788 current->flags |= orig_flags & flags; 1789 } 1790 1791 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1792 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); 1793 #ifdef CONFIG_SMP 1794 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1795 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1796 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1797 extern void release_user_cpus_ptr(struct task_struct *p); 1798 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1799 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1800 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1801 #else 1802 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1803 { 1804 } 1805 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1806 { 1807 if (!cpumask_test_cpu(0, new_mask)) 1808 return -EINVAL; 1809 return 0; 1810 } 1811 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1812 { 1813 if (src->user_cpus_ptr) 1814 return -EINVAL; 1815 return 0; 1816 } 1817 static inline void release_user_cpus_ptr(struct task_struct *p) 1818 { 1819 WARN_ON(p->user_cpus_ptr); 1820 } 1821 1822 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1823 { 1824 return 0; 1825 } 1826 #endif 1827 1828 extern int yield_to(struct task_struct *p, bool preempt); 1829 extern void set_user_nice(struct task_struct *p, long nice); 1830 extern int task_prio(const struct task_struct *p); 1831 1832 /** 1833 * task_nice - return the nice value of a given task. 1834 * @p: the task in question. 1835 * 1836 * Return: The nice value [ -20 ... 0 ... 19 ]. 1837 */ 1838 static inline int task_nice(const struct task_struct *p) 1839 { 1840 return PRIO_TO_NICE((p)->static_prio); 1841 } 1842 1843 extern int can_nice(const struct task_struct *p, const int nice); 1844 extern int task_curr(const struct task_struct *p); 1845 extern int idle_cpu(int cpu); 1846 extern int available_idle_cpu(int cpu); 1847 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1848 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1849 extern void sched_set_fifo(struct task_struct *p); 1850 extern void sched_set_fifo_low(struct task_struct *p); 1851 extern void sched_set_normal(struct task_struct *p, int nice); 1852 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1853 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1854 extern struct task_struct *idle_task(int cpu); 1855 1856 /** 1857 * is_idle_task - is the specified task an idle task? 1858 * @p: the task in question. 1859 * 1860 * Return: 1 if @p is an idle task. 0 otherwise. 1861 */ 1862 static __always_inline bool is_idle_task(const struct task_struct *p) 1863 { 1864 return !!(p->flags & PF_IDLE); 1865 } 1866 1867 extern struct task_struct *curr_task(int cpu); 1868 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1869 1870 void yield(void); 1871 1872 union thread_union { 1873 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1874 struct task_struct task; 1875 #endif 1876 #ifndef CONFIG_THREAD_INFO_IN_TASK 1877 struct thread_info thread_info; 1878 #endif 1879 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1880 }; 1881 1882 #ifndef CONFIG_THREAD_INFO_IN_TASK 1883 extern struct thread_info init_thread_info; 1884 #endif 1885 1886 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1887 1888 #ifdef CONFIG_THREAD_INFO_IN_TASK 1889 static inline struct thread_info *task_thread_info(struct task_struct *task) 1890 { 1891 return &task->thread_info; 1892 } 1893 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1894 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1895 #endif 1896 1897 /* 1898 * find a task by one of its numerical ids 1899 * 1900 * find_task_by_pid_ns(): 1901 * finds a task by its pid in the specified namespace 1902 * find_task_by_vpid(): 1903 * finds a task by its virtual pid 1904 * 1905 * see also find_vpid() etc in include/linux/pid.h 1906 */ 1907 1908 extern struct task_struct *find_task_by_vpid(pid_t nr); 1909 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1910 1911 /* 1912 * find a task by its virtual pid and get the task struct 1913 */ 1914 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1915 1916 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1917 extern int wake_up_process(struct task_struct *tsk); 1918 extern void wake_up_new_task(struct task_struct *tsk); 1919 1920 #ifdef CONFIG_SMP 1921 extern void kick_process(struct task_struct *tsk); 1922 #else 1923 static inline void kick_process(struct task_struct *tsk) { } 1924 #endif 1925 1926 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1927 1928 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1929 { 1930 __set_task_comm(tsk, from, false); 1931 } 1932 1933 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1934 #define get_task_comm(buf, tsk) ({ \ 1935 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1936 __get_task_comm(buf, sizeof(buf), tsk); \ 1937 }) 1938 1939 #ifdef CONFIG_SMP 1940 static __always_inline void scheduler_ipi(void) 1941 { 1942 /* 1943 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1944 * TIF_NEED_RESCHED remotely (for the first time) will also send 1945 * this IPI. 1946 */ 1947 preempt_fold_need_resched(); 1948 } 1949 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1950 #else 1951 static inline void scheduler_ipi(void) { } 1952 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 1953 { 1954 return 1; 1955 } 1956 #endif 1957 1958 /* 1959 * Set thread flags in other task's structures. 1960 * See asm/thread_info.h for TIF_xxxx flags available: 1961 */ 1962 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1963 { 1964 set_ti_thread_flag(task_thread_info(tsk), flag); 1965 } 1966 1967 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1968 { 1969 clear_ti_thread_flag(task_thread_info(tsk), flag); 1970 } 1971 1972 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 1973 bool value) 1974 { 1975 update_ti_thread_flag(task_thread_info(tsk), flag, value); 1976 } 1977 1978 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1979 { 1980 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1981 } 1982 1983 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1984 { 1985 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1986 } 1987 1988 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1989 { 1990 return test_ti_thread_flag(task_thread_info(tsk), flag); 1991 } 1992 1993 static inline void set_tsk_need_resched(struct task_struct *tsk) 1994 { 1995 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1996 } 1997 1998 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1999 { 2000 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2001 } 2002 2003 static inline int test_tsk_need_resched(struct task_struct *tsk) 2004 { 2005 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2006 } 2007 2008 /* 2009 * cond_resched() and cond_resched_lock(): latency reduction via 2010 * explicit rescheduling in places that are safe. The return 2011 * value indicates whether a reschedule was done in fact. 2012 * cond_resched_lock() will drop the spinlock before scheduling, 2013 */ 2014 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2015 extern int __cond_resched(void); 2016 2017 #ifdef CONFIG_PREEMPT_DYNAMIC 2018 2019 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2020 2021 static __always_inline int _cond_resched(void) 2022 { 2023 return static_call_mod(cond_resched)(); 2024 } 2025 2026 #else 2027 2028 static inline int _cond_resched(void) 2029 { 2030 return __cond_resched(); 2031 } 2032 2033 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2034 2035 #else 2036 2037 static inline int _cond_resched(void) { return 0; } 2038 2039 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2040 2041 #define cond_resched() ({ \ 2042 ___might_sleep(__FILE__, __LINE__, 0); \ 2043 _cond_resched(); \ 2044 }) 2045 2046 extern int __cond_resched_lock(spinlock_t *lock); 2047 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2048 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2049 2050 #define cond_resched_lock(lock) ({ \ 2051 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\ 2052 __cond_resched_lock(lock); \ 2053 }) 2054 2055 #define cond_resched_rwlock_read(lock) ({ \ 2056 __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ 2057 __cond_resched_rwlock_read(lock); \ 2058 }) 2059 2060 #define cond_resched_rwlock_write(lock) ({ \ 2061 __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \ 2062 __cond_resched_rwlock_write(lock); \ 2063 }) 2064 2065 static inline void cond_resched_rcu(void) 2066 { 2067 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2068 rcu_read_unlock(); 2069 cond_resched(); 2070 rcu_read_lock(); 2071 #endif 2072 } 2073 2074 /* 2075 * Does a critical section need to be broken due to another 2076 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2077 * but a general need for low latency) 2078 */ 2079 static inline int spin_needbreak(spinlock_t *lock) 2080 { 2081 #ifdef CONFIG_PREEMPTION 2082 return spin_is_contended(lock); 2083 #else 2084 return 0; 2085 #endif 2086 } 2087 2088 /* 2089 * Check if a rwlock is contended. 2090 * Returns non-zero if there is another task waiting on the rwlock. 2091 * Returns zero if the lock is not contended or the system / underlying 2092 * rwlock implementation does not support contention detection. 2093 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2094 * for low latency. 2095 */ 2096 static inline int rwlock_needbreak(rwlock_t *lock) 2097 { 2098 #ifdef CONFIG_PREEMPTION 2099 return rwlock_is_contended(lock); 2100 #else 2101 return 0; 2102 #endif 2103 } 2104 2105 static __always_inline bool need_resched(void) 2106 { 2107 return unlikely(tif_need_resched()); 2108 } 2109 2110 /* 2111 * Wrappers for p->thread_info->cpu access. No-op on UP. 2112 */ 2113 #ifdef CONFIG_SMP 2114 2115 static inline unsigned int task_cpu(const struct task_struct *p) 2116 { 2117 #ifdef CONFIG_THREAD_INFO_IN_TASK 2118 return READ_ONCE(p->cpu); 2119 #else 2120 return READ_ONCE(task_thread_info(p)->cpu); 2121 #endif 2122 } 2123 2124 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2125 2126 #else 2127 2128 static inline unsigned int task_cpu(const struct task_struct *p) 2129 { 2130 return 0; 2131 } 2132 2133 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2134 { 2135 } 2136 2137 #endif /* CONFIG_SMP */ 2138 2139 extern bool sched_task_on_rq(struct task_struct *p); 2140 2141 /* 2142 * In order to reduce various lock holder preemption latencies provide an 2143 * interface to see if a vCPU is currently running or not. 2144 * 2145 * This allows us to terminate optimistic spin loops and block, analogous to 2146 * the native optimistic spin heuristic of testing if the lock owner task is 2147 * running or not. 2148 */ 2149 #ifndef vcpu_is_preempted 2150 static inline bool vcpu_is_preempted(int cpu) 2151 { 2152 return false; 2153 } 2154 #endif 2155 2156 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2157 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2158 2159 #ifndef TASK_SIZE_OF 2160 #define TASK_SIZE_OF(tsk) TASK_SIZE 2161 #endif 2162 2163 #ifdef CONFIG_SMP 2164 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2165 unsigned long sched_cpu_util(int cpu, unsigned long max); 2166 #endif /* CONFIG_SMP */ 2167 2168 #ifdef CONFIG_RSEQ 2169 2170 /* 2171 * Map the event mask on the user-space ABI enum rseq_cs_flags 2172 * for direct mask checks. 2173 */ 2174 enum rseq_event_mask_bits { 2175 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2176 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2177 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2178 }; 2179 2180 enum rseq_event_mask { 2181 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2182 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2183 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2184 }; 2185 2186 static inline void rseq_set_notify_resume(struct task_struct *t) 2187 { 2188 if (t->rseq) 2189 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2190 } 2191 2192 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2193 2194 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2195 struct pt_regs *regs) 2196 { 2197 if (current->rseq) 2198 __rseq_handle_notify_resume(ksig, regs); 2199 } 2200 2201 static inline void rseq_signal_deliver(struct ksignal *ksig, 2202 struct pt_regs *regs) 2203 { 2204 preempt_disable(); 2205 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2206 preempt_enable(); 2207 rseq_handle_notify_resume(ksig, regs); 2208 } 2209 2210 /* rseq_preempt() requires preemption to be disabled. */ 2211 static inline void rseq_preempt(struct task_struct *t) 2212 { 2213 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2214 rseq_set_notify_resume(t); 2215 } 2216 2217 /* rseq_migrate() requires preemption to be disabled. */ 2218 static inline void rseq_migrate(struct task_struct *t) 2219 { 2220 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2221 rseq_set_notify_resume(t); 2222 } 2223 2224 /* 2225 * If parent process has a registered restartable sequences area, the 2226 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2227 */ 2228 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2229 { 2230 if (clone_flags & CLONE_VM) { 2231 t->rseq = NULL; 2232 t->rseq_sig = 0; 2233 t->rseq_event_mask = 0; 2234 } else { 2235 t->rseq = current->rseq; 2236 t->rseq_sig = current->rseq_sig; 2237 t->rseq_event_mask = current->rseq_event_mask; 2238 } 2239 } 2240 2241 static inline void rseq_execve(struct task_struct *t) 2242 { 2243 t->rseq = NULL; 2244 t->rseq_sig = 0; 2245 t->rseq_event_mask = 0; 2246 } 2247 2248 #else 2249 2250 static inline void rseq_set_notify_resume(struct task_struct *t) 2251 { 2252 } 2253 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2254 struct pt_regs *regs) 2255 { 2256 } 2257 static inline void rseq_signal_deliver(struct ksignal *ksig, 2258 struct pt_regs *regs) 2259 { 2260 } 2261 static inline void rseq_preempt(struct task_struct *t) 2262 { 2263 } 2264 static inline void rseq_migrate(struct task_struct *t) 2265 { 2266 } 2267 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2268 { 2269 } 2270 static inline void rseq_execve(struct task_struct *t) 2271 { 2272 } 2273 2274 #endif 2275 2276 #ifdef CONFIG_DEBUG_RSEQ 2277 2278 void rseq_syscall(struct pt_regs *regs); 2279 2280 #else 2281 2282 static inline void rseq_syscall(struct pt_regs *regs) 2283 { 2284 } 2285 2286 #endif 2287 2288 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq); 2289 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len); 2290 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq); 2291 2292 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq); 2293 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq); 2294 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq); 2295 2296 int sched_trace_rq_cpu(struct rq *rq); 2297 int sched_trace_rq_cpu_capacity(struct rq *rq); 2298 int sched_trace_rq_nr_running(struct rq *rq); 2299 2300 const struct cpumask *sched_trace_rd_span(struct root_domain *rd); 2301 2302 #ifdef CONFIG_SCHED_CORE 2303 extern void sched_core_free(struct task_struct *tsk); 2304 extern void sched_core_fork(struct task_struct *p); 2305 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2306 unsigned long uaddr); 2307 #else 2308 static inline void sched_core_free(struct task_struct *tsk) { } 2309 static inline void sched_core_fork(struct task_struct *p) { } 2310 #endif 2311 2312 #endif 2313