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