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