1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SCHED_H 3 #define _LINUX_SCHED_H 4 5 /* 6 * Define 'struct task_struct' and provide the main scheduler 7 * APIs (schedule(), wakeup variants, etc.) 8 */ 9 10 #include <uapi/linux/sched.h> 11 12 #include <asm/current.h> 13 #include <asm/processor.h> 14 #include <linux/thread_info.h> 15 #include <linux/preempt.h> 16 #include <linux/cpumask.h> 17 18 #include <linux/cache.h> 19 #include <linux/irqflags_types.h> 20 #include <linux/smp_types.h> 21 #include <linux/pid_types.h> 22 #include <linux/sem_types.h> 23 #include <linux/shm.h> 24 #include <linux/kmsan_types.h> 25 #include <linux/mutex_types.h> 26 #include <linux/plist_types.h> 27 #include <linux/hrtimer_types.h> 28 #include <linux/timer_types.h> 29 #include <linux/seccomp_types.h> 30 #include <linux/nodemask_types.h> 31 #include <linux/refcount_types.h> 32 #include <linux/resource.h> 33 #include <linux/latencytop.h> 34 #include <linux/sched/prio.h> 35 #include <linux/sched/types.h> 36 #include <linux/signal_types.h> 37 #include <linux/syscall_user_dispatch_types.h> 38 #include <linux/mm_types_task.h> 39 #include <linux/task_io_accounting.h> 40 #include <linux/posix-timers_types.h> 41 #include <linux/restart_block.h> 42 #include <uapi/linux/rseq.h> 43 #include <linux/seqlock_types.h> 44 #include <linux/kcsan.h> 45 #include <linux/rv.h> 46 #include <linux/livepatch_sched.h> 47 #include <linux/uidgid_types.h> 48 #include <asm/kmap_size.h> 49 50 /* task_struct member predeclarations (sorted alphabetically): */ 51 struct audit_context; 52 struct bio_list; 53 struct blk_plug; 54 struct bpf_local_storage; 55 struct bpf_run_ctx; 56 struct capture_control; 57 struct cfs_rq; 58 struct fs_struct; 59 struct futex_pi_state; 60 struct io_context; 61 struct io_uring_task; 62 struct mempolicy; 63 struct nameidata; 64 struct nsproxy; 65 struct perf_event_context; 66 struct pid_namespace; 67 struct pipe_inode_info; 68 struct rcu_node; 69 struct reclaim_state; 70 struct robust_list_head; 71 struct root_domain; 72 struct rq; 73 struct sched_attr; 74 struct sched_dl_entity; 75 struct seq_file; 76 struct sighand_struct; 77 struct signal_struct; 78 struct task_delay_info; 79 struct task_group; 80 struct task_struct; 81 struct user_event_mm; 82 83 /* 84 * Task state bitmask. NOTE! These bits are also 85 * encoded in fs/proc/array.c: get_task_state(). 86 * 87 * We have two separate sets of flags: task->__state 88 * is about runnability, while task->exit_state are 89 * about the task exiting. Confusing, but this way 90 * modifying one set can't modify the other one by 91 * mistake. 92 */ 93 94 /* Used in tsk->__state: */ 95 #define TASK_RUNNING 0x00000000 96 #define TASK_INTERRUPTIBLE 0x00000001 97 #define TASK_UNINTERRUPTIBLE 0x00000002 98 #define __TASK_STOPPED 0x00000004 99 #define __TASK_TRACED 0x00000008 100 /* Used in tsk->exit_state: */ 101 #define EXIT_DEAD 0x00000010 102 #define EXIT_ZOMBIE 0x00000020 103 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 104 /* Used in tsk->__state again: */ 105 #define TASK_PARKED 0x00000040 106 #define TASK_DEAD 0x00000080 107 #define TASK_WAKEKILL 0x00000100 108 #define TASK_WAKING 0x00000200 109 #define TASK_NOLOAD 0x00000400 110 #define TASK_NEW 0x00000800 111 #define TASK_RTLOCK_WAIT 0x00001000 112 #define TASK_FREEZABLE 0x00002000 113 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 114 #define TASK_FROZEN 0x00008000 115 #define TASK_STATE_MAX 0x00010000 116 117 #define TASK_ANY (TASK_STATE_MAX-1) 118 119 /* 120 * DO NOT ADD ANY NEW USERS ! 121 */ 122 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 123 124 /* Convenience macros for the sake of set_current_state: */ 125 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 126 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 127 #define TASK_TRACED __TASK_TRACED 128 129 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 130 131 /* Convenience macros for the sake of wake_up(): */ 132 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 133 134 /* get_task_state(): */ 135 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 136 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 137 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 138 TASK_PARKED) 139 140 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 141 142 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 143 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 144 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 145 146 /* 147 * Special states are those that do not use the normal wait-loop pattern. See 148 * the comment with set_special_state(). 149 */ 150 #define is_special_task_state(state) \ 151 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 152 153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 154 # define debug_normal_state_change(state_value) \ 155 do { \ 156 WARN_ON_ONCE(is_special_task_state(state_value)); \ 157 current->task_state_change = _THIS_IP_; \ 158 } while (0) 159 160 # define debug_special_state_change(state_value) \ 161 do { \ 162 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 163 current->task_state_change = _THIS_IP_; \ 164 } while (0) 165 166 # define debug_rtlock_wait_set_state() \ 167 do { \ 168 current->saved_state_change = current->task_state_change;\ 169 current->task_state_change = _THIS_IP_; \ 170 } while (0) 171 172 # define debug_rtlock_wait_restore_state() \ 173 do { \ 174 current->task_state_change = current->saved_state_change;\ 175 } while (0) 176 177 #else 178 # define debug_normal_state_change(cond) do { } while (0) 179 # define debug_special_state_change(cond) do { } while (0) 180 # define debug_rtlock_wait_set_state() do { } while (0) 181 # define debug_rtlock_wait_restore_state() do { } while (0) 182 #endif 183 184 /* 185 * set_current_state() includes a barrier so that the write of current->__state 186 * is correctly serialised wrt the caller's subsequent test of whether to 187 * actually sleep: 188 * 189 * for (;;) { 190 * set_current_state(TASK_UNINTERRUPTIBLE); 191 * if (CONDITION) 192 * break; 193 * 194 * schedule(); 195 * } 196 * __set_current_state(TASK_RUNNING); 197 * 198 * If the caller does not need such serialisation (because, for instance, the 199 * CONDITION test and condition change and wakeup are under the same lock) then 200 * use __set_current_state(). 201 * 202 * The above is typically ordered against the wakeup, which does: 203 * 204 * CONDITION = 1; 205 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 206 * 207 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 208 * accessing p->__state. 209 * 210 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is, 211 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 212 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 213 * 214 * However, with slightly different timing the wakeup TASK_RUNNING store can 215 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 216 * a problem either because that will result in one extra go around the loop 217 * and our @cond test will save the day. 218 * 219 * Also see the comments of try_to_wake_up(). 220 */ 221 #define __set_current_state(state_value) \ 222 do { \ 223 debug_normal_state_change((state_value)); \ 224 WRITE_ONCE(current->__state, (state_value)); \ 225 } while (0) 226 227 #define set_current_state(state_value) \ 228 do { \ 229 debug_normal_state_change((state_value)); \ 230 smp_store_mb(current->__state, (state_value)); \ 231 } while (0) 232 233 /* 234 * set_special_state() should be used for those states when the blocking task 235 * can not use the regular condition based wait-loop. In that case we must 236 * serialize against wakeups such that any possible in-flight TASK_RUNNING 237 * stores will not collide with our state change. 238 */ 239 #define set_special_state(state_value) \ 240 do { \ 241 unsigned long flags; /* may shadow */ \ 242 \ 243 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 244 debug_special_state_change((state_value)); \ 245 WRITE_ONCE(current->__state, (state_value)); \ 246 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 247 } while (0) 248 249 /* 250 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 251 * 252 * RT's spin/rwlock substitutions are state preserving. The state of the 253 * task when blocking on the lock is saved in task_struct::saved_state and 254 * restored after the lock has been acquired. These operations are 255 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 256 * lock related wakeups while the task is blocked on the lock are 257 * redirected to operate on task_struct::saved_state to ensure that these 258 * are not dropped. On restore task_struct::saved_state is set to 259 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 260 * 261 * The lock operation looks like this: 262 * 263 * current_save_and_set_rtlock_wait_state(); 264 * for (;;) { 265 * if (try_lock()) 266 * break; 267 * raw_spin_unlock_irq(&lock->wait_lock); 268 * schedule_rtlock(); 269 * raw_spin_lock_irq(&lock->wait_lock); 270 * set_current_state(TASK_RTLOCK_WAIT); 271 * } 272 * current_restore_rtlock_saved_state(); 273 */ 274 #define current_save_and_set_rtlock_wait_state() \ 275 do { \ 276 lockdep_assert_irqs_disabled(); \ 277 raw_spin_lock(¤t->pi_lock); \ 278 current->saved_state = current->__state; \ 279 debug_rtlock_wait_set_state(); \ 280 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 281 raw_spin_unlock(¤t->pi_lock); \ 282 } while (0); 283 284 #define current_restore_rtlock_saved_state() \ 285 do { \ 286 lockdep_assert_irqs_disabled(); \ 287 raw_spin_lock(¤t->pi_lock); \ 288 debug_rtlock_wait_restore_state(); \ 289 WRITE_ONCE(current->__state, current->saved_state); \ 290 current->saved_state = TASK_RUNNING; \ 291 raw_spin_unlock(¤t->pi_lock); \ 292 } while (0); 293 294 #define get_current_state() READ_ONCE(current->__state) 295 296 /* 297 * Define the task command name length as enum, then it can be visible to 298 * BPF programs. 299 */ 300 enum { 301 TASK_COMM_LEN = 16, 302 }; 303 304 extern void sched_tick(void); 305 306 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 307 308 extern long schedule_timeout(long timeout); 309 extern long schedule_timeout_interruptible(long timeout); 310 extern long schedule_timeout_killable(long timeout); 311 extern long schedule_timeout_uninterruptible(long timeout); 312 extern long schedule_timeout_idle(long timeout); 313 asmlinkage void schedule(void); 314 extern void schedule_preempt_disabled(void); 315 asmlinkage void preempt_schedule_irq(void); 316 #ifdef CONFIG_PREEMPT_RT 317 extern void schedule_rtlock(void); 318 #endif 319 320 extern int __must_check io_schedule_prepare(void); 321 extern void io_schedule_finish(int token); 322 extern long io_schedule_timeout(long timeout); 323 extern void io_schedule(void); 324 325 /** 326 * struct prev_cputime - snapshot of system and user cputime 327 * @utime: time spent in user mode 328 * @stime: time spent in system mode 329 * @lock: protects the above two fields 330 * 331 * Stores previous user/system time values such that we can guarantee 332 * monotonicity. 333 */ 334 struct prev_cputime { 335 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 336 u64 utime; 337 u64 stime; 338 raw_spinlock_t lock; 339 #endif 340 }; 341 342 enum vtime_state { 343 /* Task is sleeping or running in a CPU with VTIME inactive: */ 344 VTIME_INACTIVE = 0, 345 /* Task is idle */ 346 VTIME_IDLE, 347 /* Task runs in kernelspace in a CPU with VTIME active: */ 348 VTIME_SYS, 349 /* Task runs in userspace in a CPU with VTIME active: */ 350 VTIME_USER, 351 /* Task runs as guests in a CPU with VTIME active: */ 352 VTIME_GUEST, 353 }; 354 355 struct vtime { 356 seqcount_t seqcount; 357 unsigned long long starttime; 358 enum vtime_state state; 359 unsigned int cpu; 360 u64 utime; 361 u64 stime; 362 u64 gtime; 363 }; 364 365 /* 366 * Utilization clamp constraints. 367 * @UCLAMP_MIN: Minimum utilization 368 * @UCLAMP_MAX: Maximum utilization 369 * @UCLAMP_CNT: Utilization clamp constraints count 370 */ 371 enum uclamp_id { 372 UCLAMP_MIN = 0, 373 UCLAMP_MAX, 374 UCLAMP_CNT 375 }; 376 377 #ifdef CONFIG_SMP 378 extern struct root_domain def_root_domain; 379 extern struct mutex sched_domains_mutex; 380 #endif 381 382 struct sched_param { 383 int sched_priority; 384 }; 385 386 struct sched_info { 387 #ifdef CONFIG_SCHED_INFO 388 /* Cumulative counters: */ 389 390 /* # of times we have run on this CPU: */ 391 unsigned long pcount; 392 393 /* Time spent waiting on a runqueue: */ 394 unsigned long long run_delay; 395 396 /* Timestamps: */ 397 398 /* When did we last run on a CPU? */ 399 unsigned long long last_arrival; 400 401 /* When were we last queued to run? */ 402 unsigned long long last_queued; 403 404 #endif /* CONFIG_SCHED_INFO */ 405 }; 406 407 /* 408 * Integer metrics need fixed point arithmetic, e.g., sched/fair 409 * has a few: load, load_avg, util_avg, freq, and capacity. 410 * 411 * We define a basic fixed point arithmetic range, and then formalize 412 * all these metrics based on that basic range. 413 */ 414 # define SCHED_FIXEDPOINT_SHIFT 10 415 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 416 417 /* Increase resolution of cpu_capacity calculations */ 418 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 419 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 420 421 struct load_weight { 422 unsigned long weight; 423 u32 inv_weight; 424 }; 425 426 /* 427 * The load/runnable/util_avg accumulates an infinite geometric series 428 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 429 * 430 * [load_avg definition] 431 * 432 * load_avg = runnable% * scale_load_down(load) 433 * 434 * [runnable_avg definition] 435 * 436 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 437 * 438 * [util_avg definition] 439 * 440 * util_avg = running% * SCHED_CAPACITY_SCALE 441 * 442 * where runnable% is the time ratio that a sched_entity is runnable and 443 * running% the time ratio that a sched_entity is running. 444 * 445 * For cfs_rq, they are the aggregated values of all runnable and blocked 446 * sched_entities. 447 * 448 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 449 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 450 * for computing those signals (see update_rq_clock_pelt()) 451 * 452 * N.B., the above ratios (runnable% and running%) themselves are in the 453 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 454 * to as large a range as necessary. This is for example reflected by 455 * util_avg's SCHED_CAPACITY_SCALE. 456 * 457 * [Overflow issue] 458 * 459 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 460 * with the highest load (=88761), always runnable on a single cfs_rq, 461 * and should not overflow as the number already hits PID_MAX_LIMIT. 462 * 463 * For all other cases (including 32-bit kernels), struct load_weight's 464 * weight will overflow first before we do, because: 465 * 466 * Max(load_avg) <= Max(load.weight) 467 * 468 * Then it is the load_weight's responsibility to consider overflow 469 * issues. 470 */ 471 struct sched_avg { 472 u64 last_update_time; 473 u64 load_sum; 474 u64 runnable_sum; 475 u32 util_sum; 476 u32 period_contrib; 477 unsigned long load_avg; 478 unsigned long runnable_avg; 479 unsigned long util_avg; 480 unsigned int util_est; 481 } ____cacheline_aligned; 482 483 /* 484 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 485 * updates. When a task is dequeued, its util_est should not be updated if its 486 * util_avg has not been updated in the meantime. 487 * This information is mapped into the MSB bit of util_est at dequeue time. 488 * Since max value of util_est for a task is 1024 (PELT util_avg for a task) 489 * it is safe to use MSB. 490 */ 491 #define UTIL_EST_WEIGHT_SHIFT 2 492 #define UTIL_AVG_UNCHANGED 0x80000000 493 494 struct sched_statistics { 495 #ifdef CONFIG_SCHEDSTATS 496 u64 wait_start; 497 u64 wait_max; 498 u64 wait_count; 499 u64 wait_sum; 500 u64 iowait_count; 501 u64 iowait_sum; 502 503 u64 sleep_start; 504 u64 sleep_max; 505 s64 sum_sleep_runtime; 506 507 u64 block_start; 508 u64 block_max; 509 s64 sum_block_runtime; 510 511 s64 exec_max; 512 u64 slice_max; 513 514 u64 nr_migrations_cold; 515 u64 nr_failed_migrations_affine; 516 u64 nr_failed_migrations_running; 517 u64 nr_failed_migrations_hot; 518 u64 nr_forced_migrations; 519 520 u64 nr_wakeups; 521 u64 nr_wakeups_sync; 522 u64 nr_wakeups_migrate; 523 u64 nr_wakeups_local; 524 u64 nr_wakeups_remote; 525 u64 nr_wakeups_affine; 526 u64 nr_wakeups_affine_attempts; 527 u64 nr_wakeups_passive; 528 u64 nr_wakeups_idle; 529 530 #ifdef CONFIG_SCHED_CORE 531 u64 core_forceidle_sum; 532 #endif 533 #endif /* CONFIG_SCHEDSTATS */ 534 } ____cacheline_aligned; 535 536 struct sched_entity { 537 /* For load-balancing: */ 538 struct load_weight load; 539 struct rb_node run_node; 540 u64 deadline; 541 u64 min_vruntime; 542 543 struct list_head group_node; 544 unsigned int on_rq; 545 546 u64 exec_start; 547 u64 sum_exec_runtime; 548 u64 prev_sum_exec_runtime; 549 u64 vruntime; 550 s64 vlag; 551 u64 slice; 552 553 u64 nr_migrations; 554 555 #ifdef CONFIG_FAIR_GROUP_SCHED 556 int depth; 557 struct sched_entity *parent; 558 /* rq on which this entity is (to be) queued: */ 559 struct cfs_rq *cfs_rq; 560 /* rq "owned" by this entity/group: */ 561 struct cfs_rq *my_q; 562 /* cached value of my_q->h_nr_running */ 563 unsigned long runnable_weight; 564 #endif 565 566 #ifdef CONFIG_SMP 567 /* 568 * Per entity load average tracking. 569 * 570 * Put into separate cache line so it does not 571 * collide with read-mostly values above. 572 */ 573 struct sched_avg avg; 574 #endif 575 }; 576 577 struct sched_rt_entity { 578 struct list_head run_list; 579 unsigned long timeout; 580 unsigned long watchdog_stamp; 581 unsigned int time_slice; 582 unsigned short on_rq; 583 unsigned short on_list; 584 585 struct sched_rt_entity *back; 586 #ifdef CONFIG_RT_GROUP_SCHED 587 struct sched_rt_entity *parent; 588 /* rq on which this entity is (to be) queued: */ 589 struct rt_rq *rt_rq; 590 /* rq "owned" by this entity/group: */ 591 struct rt_rq *my_q; 592 #endif 593 } __randomize_layout; 594 595 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *); 596 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *); 597 598 struct sched_dl_entity { 599 struct rb_node rb_node; 600 601 /* 602 * Original scheduling parameters. Copied here from sched_attr 603 * during sched_setattr(), they will remain the same until 604 * the next sched_setattr(). 605 */ 606 u64 dl_runtime; /* Maximum runtime for each instance */ 607 u64 dl_deadline; /* Relative deadline of each instance */ 608 u64 dl_period; /* Separation of two instances (period) */ 609 u64 dl_bw; /* dl_runtime / dl_period */ 610 u64 dl_density; /* dl_runtime / dl_deadline */ 611 612 /* 613 * Actual scheduling parameters. Initialized with the values above, 614 * they are continuously updated during task execution. Note that 615 * the remaining runtime could be < 0 in case we are in overrun. 616 */ 617 s64 runtime; /* Remaining runtime for this instance */ 618 u64 deadline; /* Absolute deadline for this instance */ 619 unsigned int flags; /* Specifying the scheduler behaviour */ 620 621 /* 622 * Some bool flags: 623 * 624 * @dl_throttled tells if we exhausted the runtime. If so, the 625 * task has to wait for a replenishment to be performed at the 626 * next firing of dl_timer. 627 * 628 * @dl_yielded tells if task gave up the CPU before consuming 629 * all its available runtime during the last job. 630 * 631 * @dl_non_contending tells if the task is inactive while still 632 * contributing to the active utilization. In other words, it 633 * indicates if the inactive timer has been armed and its handler 634 * has not been executed yet. This flag is useful to avoid race 635 * conditions between the inactive timer handler and the wakeup 636 * code. 637 * 638 * @dl_overrun tells if the task asked to be informed about runtime 639 * overruns. 640 */ 641 unsigned int dl_throttled : 1; 642 unsigned int dl_yielded : 1; 643 unsigned int dl_non_contending : 1; 644 unsigned int dl_overrun : 1; 645 unsigned int dl_server : 1; 646 647 /* 648 * Bandwidth enforcement timer. Each -deadline task has its 649 * own bandwidth to be enforced, thus we need one timer per task. 650 */ 651 struct hrtimer dl_timer; 652 653 /* 654 * Inactive timer, responsible for decreasing the active utilization 655 * at the "0-lag time". When a -deadline task blocks, it contributes 656 * to GRUB's active utilization until the "0-lag time", hence a 657 * timer is needed to decrease the active utilization at the correct 658 * time. 659 */ 660 struct hrtimer inactive_timer; 661 662 /* 663 * Bits for DL-server functionality. Also see the comment near 664 * dl_server_update(). 665 * 666 * @rq the runqueue this server is for 667 * 668 * @server_has_tasks() returns true if @server_pick return a 669 * runnable task. 670 */ 671 struct rq *rq; 672 dl_server_has_tasks_f server_has_tasks; 673 dl_server_pick_f server_pick; 674 675 #ifdef CONFIG_RT_MUTEXES 676 /* 677 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 678 * pi_se points to the donor, otherwise points to the dl_se it belongs 679 * to (the original one/itself). 680 */ 681 struct sched_dl_entity *pi_se; 682 #endif 683 }; 684 685 #ifdef CONFIG_UCLAMP_TASK 686 /* Number of utilization clamp buckets (shorter alias) */ 687 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 688 689 /* 690 * Utilization clamp for a scheduling entity 691 * @value: clamp value "assigned" to a se 692 * @bucket_id: bucket index corresponding to the "assigned" value 693 * @active: the se is currently refcounted in a rq's bucket 694 * @user_defined: the requested clamp value comes from user-space 695 * 696 * The bucket_id is the index of the clamp bucket matching the clamp value 697 * which is pre-computed and stored to avoid expensive integer divisions from 698 * the fast path. 699 * 700 * The active bit is set whenever a task has got an "effective" value assigned, 701 * which can be different from the clamp value "requested" from user-space. 702 * This allows to know a task is refcounted in the rq's bucket corresponding 703 * to the "effective" bucket_id. 704 * 705 * The user_defined bit is set whenever a task has got a task-specific clamp 706 * value requested from userspace, i.e. the system defaults apply to this task 707 * just as a restriction. This allows to relax default clamps when a less 708 * restrictive task-specific value has been requested, thus allowing to 709 * implement a "nice" semantic. For example, a task running with a 20% 710 * default boost can still drop its own boosting to 0%. 711 */ 712 struct uclamp_se { 713 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 714 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 715 unsigned int active : 1; 716 unsigned int user_defined : 1; 717 }; 718 #endif /* CONFIG_UCLAMP_TASK */ 719 720 union rcu_special { 721 struct { 722 u8 blocked; 723 u8 need_qs; 724 u8 exp_hint; /* Hint for performance. */ 725 u8 need_mb; /* Readers need smp_mb(). */ 726 } b; /* Bits. */ 727 u32 s; /* Set of bits. */ 728 }; 729 730 enum perf_event_task_context { 731 perf_invalid_context = -1, 732 perf_hw_context = 0, 733 perf_sw_context, 734 perf_nr_task_contexts, 735 }; 736 737 struct wake_q_node { 738 struct wake_q_node *next; 739 }; 740 741 struct kmap_ctrl { 742 #ifdef CONFIG_KMAP_LOCAL 743 int idx; 744 pte_t pteval[KM_MAX_IDX]; 745 #endif 746 }; 747 748 struct task_struct { 749 #ifdef CONFIG_THREAD_INFO_IN_TASK 750 /* 751 * For reasons of header soup (see current_thread_info()), this 752 * must be the first element of task_struct. 753 */ 754 struct thread_info thread_info; 755 #endif 756 unsigned int __state; 757 758 /* saved state for "spinlock sleepers" */ 759 unsigned int saved_state; 760 761 /* 762 * This begins the randomizable portion of task_struct. Only 763 * scheduling-critical items should be added above here. 764 */ 765 randomized_struct_fields_start 766 767 void *stack; 768 refcount_t usage; 769 /* Per task flags (PF_*), defined further below: */ 770 unsigned int flags; 771 unsigned int ptrace; 772 773 #ifdef CONFIG_SMP 774 int on_cpu; 775 struct __call_single_node wake_entry; 776 unsigned int wakee_flips; 777 unsigned long wakee_flip_decay_ts; 778 struct task_struct *last_wakee; 779 780 /* 781 * recent_used_cpu is initially set as the last CPU used by a task 782 * that wakes affine another task. Waker/wakee relationships can 783 * push tasks around a CPU where each wakeup moves to the next one. 784 * Tracking a recently used CPU allows a quick search for a recently 785 * used CPU that may be idle. 786 */ 787 int recent_used_cpu; 788 int wake_cpu; 789 #endif 790 int on_rq; 791 792 int prio; 793 int static_prio; 794 int normal_prio; 795 unsigned int rt_priority; 796 797 struct sched_entity se; 798 struct sched_rt_entity rt; 799 struct sched_dl_entity dl; 800 struct sched_dl_entity *dl_server; 801 const struct sched_class *sched_class; 802 803 #ifdef CONFIG_SCHED_CORE 804 struct rb_node core_node; 805 unsigned long core_cookie; 806 unsigned int core_occupation; 807 #endif 808 809 #ifdef CONFIG_CGROUP_SCHED 810 struct task_group *sched_task_group; 811 #endif 812 813 #ifdef CONFIG_UCLAMP_TASK 814 /* 815 * Clamp values requested for a scheduling entity. 816 * Must be updated with task_rq_lock() held. 817 */ 818 struct uclamp_se uclamp_req[UCLAMP_CNT]; 819 /* 820 * Effective clamp values used for a scheduling entity. 821 * Must be updated with task_rq_lock() held. 822 */ 823 struct uclamp_se uclamp[UCLAMP_CNT]; 824 #endif 825 826 struct sched_statistics stats; 827 828 #ifdef CONFIG_PREEMPT_NOTIFIERS 829 /* List of struct preempt_notifier: */ 830 struct hlist_head preempt_notifiers; 831 #endif 832 833 #ifdef CONFIG_BLK_DEV_IO_TRACE 834 unsigned int btrace_seq; 835 #endif 836 837 unsigned int policy; 838 unsigned long max_allowed_capacity; 839 int nr_cpus_allowed; 840 const cpumask_t *cpus_ptr; 841 cpumask_t *user_cpus_ptr; 842 cpumask_t cpus_mask; 843 void *migration_pending; 844 #ifdef CONFIG_SMP 845 unsigned short migration_disabled; 846 #endif 847 unsigned short migration_flags; 848 849 #ifdef CONFIG_PREEMPT_RCU 850 int rcu_read_lock_nesting; 851 union rcu_special rcu_read_unlock_special; 852 struct list_head rcu_node_entry; 853 struct rcu_node *rcu_blocked_node; 854 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 855 856 #ifdef CONFIG_TASKS_RCU 857 unsigned long rcu_tasks_nvcsw; 858 u8 rcu_tasks_holdout; 859 u8 rcu_tasks_idx; 860 int rcu_tasks_idle_cpu; 861 struct list_head rcu_tasks_holdout_list; 862 int rcu_tasks_exit_cpu; 863 struct list_head rcu_tasks_exit_list; 864 #endif /* #ifdef CONFIG_TASKS_RCU */ 865 866 #ifdef CONFIG_TASKS_TRACE_RCU 867 int trc_reader_nesting; 868 int trc_ipi_to_cpu; 869 union rcu_special trc_reader_special; 870 struct list_head trc_holdout_list; 871 struct list_head trc_blkd_node; 872 int trc_blkd_cpu; 873 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 874 875 struct sched_info sched_info; 876 877 struct list_head tasks; 878 #ifdef CONFIG_SMP 879 struct plist_node pushable_tasks; 880 struct rb_node pushable_dl_tasks; 881 #endif 882 883 struct mm_struct *mm; 884 struct mm_struct *active_mm; 885 struct address_space *faults_disabled_mapping; 886 887 int exit_state; 888 int exit_code; 889 int exit_signal; 890 /* The signal sent when the parent dies: */ 891 int pdeath_signal; 892 /* JOBCTL_*, siglock protected: */ 893 unsigned long jobctl; 894 895 /* Used for emulating ABI behavior of previous Linux versions: */ 896 unsigned int personality; 897 898 /* Scheduler bits, serialized by scheduler locks: */ 899 unsigned sched_reset_on_fork:1; 900 unsigned sched_contributes_to_load:1; 901 unsigned sched_migrated:1; 902 903 /* Force alignment to the next boundary: */ 904 unsigned :0; 905 906 /* Unserialized, strictly 'current' */ 907 908 /* 909 * This field must not be in the scheduler word above due to wakelist 910 * queueing no longer being serialized by p->on_cpu. However: 911 * 912 * p->XXX = X; ttwu() 913 * schedule() if (p->on_rq && ..) // false 914 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 915 * deactivate_task() ttwu_queue_wakelist()) 916 * p->on_rq = 0; p->sched_remote_wakeup = Y; 917 * 918 * guarantees all stores of 'current' are visible before 919 * ->sched_remote_wakeup gets used, so it can be in this word. 920 */ 921 unsigned sched_remote_wakeup:1; 922 #ifdef CONFIG_RT_MUTEXES 923 unsigned sched_rt_mutex:1; 924 #endif 925 926 /* Bit to tell TOMOYO we're in execve(): */ 927 unsigned in_execve:1; 928 unsigned in_iowait:1; 929 #ifndef TIF_RESTORE_SIGMASK 930 unsigned restore_sigmask:1; 931 #endif 932 #ifdef CONFIG_MEMCG 933 unsigned in_user_fault:1; 934 #endif 935 #ifdef CONFIG_LRU_GEN 936 /* whether the LRU algorithm may apply to this access */ 937 unsigned in_lru_fault:1; 938 #endif 939 #ifdef CONFIG_COMPAT_BRK 940 unsigned brk_randomized:1; 941 #endif 942 #ifdef CONFIG_CGROUPS 943 /* disallow userland-initiated cgroup migration */ 944 unsigned no_cgroup_migration:1; 945 /* task is frozen/stopped (used by the cgroup freezer) */ 946 unsigned frozen:1; 947 #endif 948 #ifdef CONFIG_BLK_CGROUP 949 unsigned use_memdelay:1; 950 #endif 951 #ifdef CONFIG_PSI 952 /* Stalled due to lack of memory */ 953 unsigned in_memstall:1; 954 #endif 955 #ifdef CONFIG_PAGE_OWNER 956 /* Used by page_owner=on to detect recursion in page tracking. */ 957 unsigned in_page_owner:1; 958 #endif 959 #ifdef CONFIG_EVENTFD 960 /* Recursion prevention for eventfd_signal() */ 961 unsigned in_eventfd:1; 962 #endif 963 #ifdef CONFIG_ARCH_HAS_CPU_PASID 964 unsigned pasid_activated:1; 965 #endif 966 #ifdef CONFIG_CPU_SUP_INTEL 967 unsigned reported_split_lock:1; 968 #endif 969 #ifdef CONFIG_TASK_DELAY_ACCT 970 /* delay due to memory thrashing */ 971 unsigned in_thrashing:1; 972 #endif 973 974 unsigned long atomic_flags; /* Flags requiring atomic access. */ 975 976 struct restart_block restart_block; 977 978 pid_t pid; 979 pid_t tgid; 980 981 #ifdef CONFIG_STACKPROTECTOR 982 /* Canary value for the -fstack-protector GCC feature: */ 983 unsigned long stack_canary; 984 #endif 985 /* 986 * Pointers to the (original) parent process, youngest child, younger sibling, 987 * older sibling, respectively. (p->father can be replaced with 988 * p->real_parent->pid) 989 */ 990 991 /* Real parent process: */ 992 struct task_struct __rcu *real_parent; 993 994 /* Recipient of SIGCHLD, wait4() reports: */ 995 struct task_struct __rcu *parent; 996 997 /* 998 * Children/sibling form the list of natural children: 999 */ 1000 struct list_head children; 1001 struct list_head sibling; 1002 struct task_struct *group_leader; 1003 1004 /* 1005 * 'ptraced' is the list of tasks this task is using ptrace() on. 1006 * 1007 * This includes both natural children and PTRACE_ATTACH targets. 1008 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 1009 */ 1010 struct list_head ptraced; 1011 struct list_head ptrace_entry; 1012 1013 /* PID/PID hash table linkage. */ 1014 struct pid *thread_pid; 1015 struct hlist_node pid_links[PIDTYPE_MAX]; 1016 struct list_head thread_node; 1017 1018 struct completion *vfork_done; 1019 1020 /* CLONE_CHILD_SETTID: */ 1021 int __user *set_child_tid; 1022 1023 /* CLONE_CHILD_CLEARTID: */ 1024 int __user *clear_child_tid; 1025 1026 /* PF_KTHREAD | PF_IO_WORKER */ 1027 void *worker_private; 1028 1029 u64 utime; 1030 u64 stime; 1031 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1032 u64 utimescaled; 1033 u64 stimescaled; 1034 #endif 1035 u64 gtime; 1036 struct prev_cputime prev_cputime; 1037 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1038 struct vtime vtime; 1039 #endif 1040 1041 #ifdef CONFIG_NO_HZ_FULL 1042 atomic_t tick_dep_mask; 1043 #endif 1044 /* Context switch counts: */ 1045 unsigned long nvcsw; 1046 unsigned long nivcsw; 1047 1048 /* Monotonic time in nsecs: */ 1049 u64 start_time; 1050 1051 /* Boot based time in nsecs: */ 1052 u64 start_boottime; 1053 1054 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1055 unsigned long min_flt; 1056 unsigned long maj_flt; 1057 1058 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1059 struct posix_cputimers posix_cputimers; 1060 1061 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1062 struct posix_cputimers_work posix_cputimers_work; 1063 #endif 1064 1065 /* Process credentials: */ 1066 1067 /* Tracer's credentials at attach: */ 1068 const struct cred __rcu *ptracer_cred; 1069 1070 /* Objective and real subjective task credentials (COW): */ 1071 const struct cred __rcu *real_cred; 1072 1073 /* Effective (overridable) subjective task credentials (COW): */ 1074 const struct cred __rcu *cred; 1075 1076 #ifdef CONFIG_KEYS 1077 /* Cached requested key. */ 1078 struct key *cached_requested_key; 1079 #endif 1080 1081 /* 1082 * executable name, excluding path. 1083 * 1084 * - normally initialized setup_new_exec() 1085 * - access it with [gs]et_task_comm() 1086 * - lock it with task_lock() 1087 */ 1088 char comm[TASK_COMM_LEN]; 1089 1090 struct nameidata *nameidata; 1091 1092 #ifdef CONFIG_SYSVIPC 1093 struct sysv_sem sysvsem; 1094 struct sysv_shm sysvshm; 1095 #endif 1096 #ifdef CONFIG_DETECT_HUNG_TASK 1097 unsigned long last_switch_count; 1098 unsigned long last_switch_time; 1099 #endif 1100 /* Filesystem information: */ 1101 struct fs_struct *fs; 1102 1103 /* Open file information: */ 1104 struct files_struct *files; 1105 1106 #ifdef CONFIG_IO_URING 1107 struct io_uring_task *io_uring; 1108 #endif 1109 1110 /* Namespaces: */ 1111 struct nsproxy *nsproxy; 1112 1113 /* Signal handlers: */ 1114 struct signal_struct *signal; 1115 struct sighand_struct __rcu *sighand; 1116 sigset_t blocked; 1117 sigset_t real_blocked; 1118 /* Restored if set_restore_sigmask() was used: */ 1119 sigset_t saved_sigmask; 1120 struct sigpending pending; 1121 unsigned long sas_ss_sp; 1122 size_t sas_ss_size; 1123 unsigned int sas_ss_flags; 1124 1125 struct callback_head *task_works; 1126 1127 #ifdef CONFIG_AUDIT 1128 #ifdef CONFIG_AUDITSYSCALL 1129 struct audit_context *audit_context; 1130 #endif 1131 kuid_t loginuid; 1132 unsigned int sessionid; 1133 #endif 1134 struct seccomp seccomp; 1135 struct syscall_user_dispatch syscall_dispatch; 1136 1137 /* Thread group tracking: */ 1138 u64 parent_exec_id; 1139 u64 self_exec_id; 1140 1141 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1142 spinlock_t alloc_lock; 1143 1144 /* Protection of the PI data structures: */ 1145 raw_spinlock_t pi_lock; 1146 1147 struct wake_q_node wake_q; 1148 1149 #ifdef CONFIG_RT_MUTEXES 1150 /* PI waiters blocked on a rt_mutex held by this task: */ 1151 struct rb_root_cached pi_waiters; 1152 /* Updated under owner's pi_lock and rq lock */ 1153 struct task_struct *pi_top_task; 1154 /* Deadlock detection and priority inheritance handling: */ 1155 struct rt_mutex_waiter *pi_blocked_on; 1156 #endif 1157 1158 #ifdef CONFIG_DEBUG_MUTEXES 1159 /* Mutex deadlock detection: */ 1160 struct mutex_waiter *blocked_on; 1161 #endif 1162 1163 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1164 int non_block_count; 1165 #endif 1166 1167 #ifdef CONFIG_TRACE_IRQFLAGS 1168 struct irqtrace_events irqtrace; 1169 unsigned int hardirq_threaded; 1170 u64 hardirq_chain_key; 1171 int softirqs_enabled; 1172 int softirq_context; 1173 int irq_config; 1174 #endif 1175 #ifdef CONFIG_PREEMPT_RT 1176 int softirq_disable_cnt; 1177 #endif 1178 1179 #ifdef CONFIG_LOCKDEP 1180 # define MAX_LOCK_DEPTH 48UL 1181 u64 curr_chain_key; 1182 int lockdep_depth; 1183 unsigned int lockdep_recursion; 1184 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1185 #endif 1186 1187 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1188 unsigned int in_ubsan; 1189 #endif 1190 1191 /* Journalling filesystem info: */ 1192 void *journal_info; 1193 1194 /* Stacked block device info: */ 1195 struct bio_list *bio_list; 1196 1197 /* Stack plugging: */ 1198 struct blk_plug *plug; 1199 1200 /* VM state: */ 1201 struct reclaim_state *reclaim_state; 1202 1203 struct io_context *io_context; 1204 1205 #ifdef CONFIG_COMPACTION 1206 struct capture_control *capture_control; 1207 #endif 1208 /* Ptrace state: */ 1209 unsigned long ptrace_message; 1210 kernel_siginfo_t *last_siginfo; 1211 1212 struct task_io_accounting ioac; 1213 #ifdef CONFIG_PSI 1214 /* Pressure stall state */ 1215 unsigned int psi_flags; 1216 #endif 1217 #ifdef CONFIG_TASK_XACCT 1218 /* Accumulated RSS usage: */ 1219 u64 acct_rss_mem1; 1220 /* Accumulated virtual memory usage: */ 1221 u64 acct_vm_mem1; 1222 /* stime + utime since last update: */ 1223 u64 acct_timexpd; 1224 #endif 1225 #ifdef CONFIG_CPUSETS 1226 /* Protected by ->alloc_lock: */ 1227 nodemask_t mems_allowed; 1228 /* Sequence number to catch updates: */ 1229 seqcount_spinlock_t mems_allowed_seq; 1230 int cpuset_mem_spread_rotor; 1231 int cpuset_slab_spread_rotor; 1232 #endif 1233 #ifdef CONFIG_CGROUPS 1234 /* Control Group info protected by css_set_lock: */ 1235 struct css_set __rcu *cgroups; 1236 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1237 struct list_head cg_list; 1238 #endif 1239 #ifdef CONFIG_X86_CPU_RESCTRL 1240 u32 closid; 1241 u32 rmid; 1242 #endif 1243 #ifdef CONFIG_FUTEX 1244 struct robust_list_head __user *robust_list; 1245 #ifdef CONFIG_COMPAT 1246 struct compat_robust_list_head __user *compat_robust_list; 1247 #endif 1248 struct list_head pi_state_list; 1249 struct futex_pi_state *pi_state_cache; 1250 struct mutex futex_exit_mutex; 1251 unsigned int futex_state; 1252 #endif 1253 #ifdef CONFIG_PERF_EVENTS 1254 struct perf_event_context *perf_event_ctxp; 1255 struct mutex perf_event_mutex; 1256 struct list_head perf_event_list; 1257 #endif 1258 #ifdef CONFIG_DEBUG_PREEMPT 1259 unsigned long preempt_disable_ip; 1260 #endif 1261 #ifdef CONFIG_NUMA 1262 /* Protected by alloc_lock: */ 1263 struct mempolicy *mempolicy; 1264 short il_prev; 1265 u8 il_weight; 1266 short pref_node_fork; 1267 #endif 1268 #ifdef CONFIG_NUMA_BALANCING 1269 int numa_scan_seq; 1270 unsigned int numa_scan_period; 1271 unsigned int numa_scan_period_max; 1272 int numa_preferred_nid; 1273 unsigned long numa_migrate_retry; 1274 /* Migration stamp: */ 1275 u64 node_stamp; 1276 u64 last_task_numa_placement; 1277 u64 last_sum_exec_runtime; 1278 struct callback_head numa_work; 1279 1280 /* 1281 * This pointer is only modified for current in syscall and 1282 * pagefault context (and for tasks being destroyed), so it can be read 1283 * from any of the following contexts: 1284 * - RCU read-side critical section 1285 * - current->numa_group from everywhere 1286 * - task's runqueue locked, task not running 1287 */ 1288 struct numa_group __rcu *numa_group; 1289 1290 /* 1291 * numa_faults is an array split into four regions: 1292 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1293 * in this precise order. 1294 * 1295 * faults_memory: Exponential decaying average of faults on a per-node 1296 * basis. Scheduling placement decisions are made based on these 1297 * counts. The values remain static for the duration of a PTE scan. 1298 * faults_cpu: Track the nodes the process was running on when a NUMA 1299 * hinting fault was incurred. 1300 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1301 * during the current scan window. When the scan completes, the counts 1302 * in faults_memory and faults_cpu decay and these values are copied. 1303 */ 1304 unsigned long *numa_faults; 1305 unsigned long total_numa_faults; 1306 1307 /* 1308 * numa_faults_locality tracks if faults recorded during the last 1309 * scan window were remote/local or failed to migrate. The task scan 1310 * period is adapted based on the locality of the faults with different 1311 * weights depending on whether they were shared or private faults 1312 */ 1313 unsigned long numa_faults_locality[3]; 1314 1315 unsigned long numa_pages_migrated; 1316 #endif /* CONFIG_NUMA_BALANCING */ 1317 1318 #ifdef CONFIG_RSEQ 1319 struct rseq __user *rseq; 1320 u32 rseq_len; 1321 u32 rseq_sig; 1322 /* 1323 * RmW on rseq_event_mask must be performed atomically 1324 * with respect to preemption. 1325 */ 1326 unsigned long rseq_event_mask; 1327 #endif 1328 1329 #ifdef CONFIG_SCHED_MM_CID 1330 int mm_cid; /* Current cid in mm */ 1331 int last_mm_cid; /* Most recent cid in mm */ 1332 int migrate_from_cpu; 1333 int mm_cid_active; /* Whether cid bitmap is active */ 1334 struct callback_head cid_work; 1335 #endif 1336 1337 struct tlbflush_unmap_batch tlb_ubc; 1338 1339 /* Cache last used pipe for splice(): */ 1340 struct pipe_inode_info *splice_pipe; 1341 1342 struct page_frag task_frag; 1343 1344 #ifdef CONFIG_TASK_DELAY_ACCT 1345 struct task_delay_info *delays; 1346 #endif 1347 1348 #ifdef CONFIG_FAULT_INJECTION 1349 int make_it_fail; 1350 unsigned int fail_nth; 1351 #endif 1352 /* 1353 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1354 * balance_dirty_pages() for a dirty throttling pause: 1355 */ 1356 int nr_dirtied; 1357 int nr_dirtied_pause; 1358 /* Start of a write-and-pause period: */ 1359 unsigned long dirty_paused_when; 1360 1361 #ifdef CONFIG_LATENCYTOP 1362 int latency_record_count; 1363 struct latency_record latency_record[LT_SAVECOUNT]; 1364 #endif 1365 /* 1366 * Time slack values; these are used to round up poll() and 1367 * select() etc timeout values. These are in nanoseconds. 1368 */ 1369 u64 timer_slack_ns; 1370 u64 default_timer_slack_ns; 1371 1372 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1373 unsigned int kasan_depth; 1374 #endif 1375 1376 #ifdef CONFIG_KCSAN 1377 struct kcsan_ctx kcsan_ctx; 1378 #ifdef CONFIG_TRACE_IRQFLAGS 1379 struct irqtrace_events kcsan_save_irqtrace; 1380 #endif 1381 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1382 int kcsan_stack_depth; 1383 #endif 1384 #endif 1385 1386 #ifdef CONFIG_KMSAN 1387 struct kmsan_ctx kmsan_ctx; 1388 #endif 1389 1390 #if IS_ENABLED(CONFIG_KUNIT) 1391 struct kunit *kunit_test; 1392 #endif 1393 1394 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1395 /* Index of current stored address in ret_stack: */ 1396 int curr_ret_stack; 1397 int curr_ret_depth; 1398 1399 /* Stack of return addresses for return function tracing: */ 1400 struct ftrace_ret_stack *ret_stack; 1401 1402 /* Timestamp for last schedule: */ 1403 unsigned long long ftrace_timestamp; 1404 1405 /* 1406 * Number of functions that haven't been traced 1407 * because of depth overrun: 1408 */ 1409 atomic_t trace_overrun; 1410 1411 /* Pause tracing: */ 1412 atomic_t tracing_graph_pause; 1413 #endif 1414 1415 #ifdef CONFIG_TRACING 1416 /* Bitmask and counter of trace recursion: */ 1417 unsigned long trace_recursion; 1418 #endif /* CONFIG_TRACING */ 1419 1420 #ifdef CONFIG_KCOV 1421 /* See kernel/kcov.c for more details. */ 1422 1423 /* Coverage collection mode enabled for this task (0 if disabled): */ 1424 unsigned int kcov_mode; 1425 1426 /* Size of the kcov_area: */ 1427 unsigned int kcov_size; 1428 1429 /* Buffer for coverage collection: */ 1430 void *kcov_area; 1431 1432 /* KCOV descriptor wired with this task or NULL: */ 1433 struct kcov *kcov; 1434 1435 /* KCOV common handle for remote coverage collection: */ 1436 u64 kcov_handle; 1437 1438 /* KCOV sequence number: */ 1439 int kcov_sequence; 1440 1441 /* Collect coverage from softirq context: */ 1442 unsigned int kcov_softirq; 1443 #endif 1444 1445 #ifdef CONFIG_MEMCG 1446 struct mem_cgroup *memcg_in_oom; 1447 gfp_t memcg_oom_gfp_mask; 1448 int memcg_oom_order; 1449 1450 /* Number of pages to reclaim on returning to userland: */ 1451 unsigned int memcg_nr_pages_over_high; 1452 1453 /* Used by memcontrol for targeted memcg charge: */ 1454 struct mem_cgroup *active_memcg; 1455 #endif 1456 1457 #ifdef CONFIG_MEMCG_KMEM 1458 struct obj_cgroup *objcg; 1459 #endif 1460 1461 #ifdef CONFIG_BLK_CGROUP 1462 struct gendisk *throttle_disk; 1463 #endif 1464 1465 #ifdef CONFIG_UPROBES 1466 struct uprobe_task *utask; 1467 #endif 1468 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1469 unsigned int sequential_io; 1470 unsigned int sequential_io_avg; 1471 #endif 1472 struct kmap_ctrl kmap_ctrl; 1473 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1474 unsigned long task_state_change; 1475 # ifdef CONFIG_PREEMPT_RT 1476 unsigned long saved_state_change; 1477 # endif 1478 #endif 1479 struct rcu_head rcu; 1480 refcount_t rcu_users; 1481 int pagefault_disabled; 1482 #ifdef CONFIG_MMU 1483 struct task_struct *oom_reaper_list; 1484 struct timer_list oom_reaper_timer; 1485 #endif 1486 #ifdef CONFIG_VMAP_STACK 1487 struct vm_struct *stack_vm_area; 1488 #endif 1489 #ifdef CONFIG_THREAD_INFO_IN_TASK 1490 /* A live task holds one reference: */ 1491 refcount_t stack_refcount; 1492 #endif 1493 #ifdef CONFIG_LIVEPATCH 1494 int patch_state; 1495 #endif 1496 #ifdef CONFIG_SECURITY 1497 /* Used by LSM modules for access restriction: */ 1498 void *security; 1499 #endif 1500 #ifdef CONFIG_BPF_SYSCALL 1501 /* Used by BPF task local storage */ 1502 struct bpf_local_storage __rcu *bpf_storage; 1503 /* Used for BPF run context */ 1504 struct bpf_run_ctx *bpf_ctx; 1505 #endif 1506 1507 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1508 unsigned long lowest_stack; 1509 unsigned long prev_lowest_stack; 1510 #endif 1511 1512 #ifdef CONFIG_X86_MCE 1513 void __user *mce_vaddr; 1514 __u64 mce_kflags; 1515 u64 mce_addr; 1516 __u64 mce_ripv : 1, 1517 mce_whole_page : 1, 1518 __mce_reserved : 62; 1519 struct callback_head mce_kill_me; 1520 int mce_count; 1521 #endif 1522 1523 #ifdef CONFIG_KRETPROBES 1524 struct llist_head kretprobe_instances; 1525 #endif 1526 #ifdef CONFIG_RETHOOK 1527 struct llist_head rethooks; 1528 #endif 1529 1530 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1531 /* 1532 * If L1D flush is supported on mm context switch 1533 * then we use this callback head to queue kill work 1534 * to kill tasks that are not running on SMT disabled 1535 * cores 1536 */ 1537 struct callback_head l1d_flush_kill; 1538 #endif 1539 1540 #ifdef CONFIG_RV 1541 /* 1542 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1543 * If we find justification for more monitors, we can think 1544 * about adding more or developing a dynamic method. So far, 1545 * none of these are justified. 1546 */ 1547 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1548 #endif 1549 1550 #ifdef CONFIG_USER_EVENTS 1551 struct user_event_mm *user_event_mm; 1552 #endif 1553 1554 /* 1555 * New fields for task_struct should be added above here, so that 1556 * they are included in the randomized portion of task_struct. 1557 */ 1558 randomized_struct_fields_end 1559 1560 /* CPU-specific state of this task: */ 1561 struct thread_struct thread; 1562 1563 /* 1564 * WARNING: on x86, 'thread_struct' contains a variable-sized 1565 * structure. It *MUST* be at the end of 'task_struct'. 1566 * 1567 * Do not put anything below here! 1568 */ 1569 }; 1570 1571 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1572 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1573 1574 static inline unsigned int __task_state_index(unsigned int tsk_state, 1575 unsigned int tsk_exit_state) 1576 { 1577 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1578 1579 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1580 1581 if ((tsk_state & TASK_IDLE) == TASK_IDLE) 1582 state = TASK_REPORT_IDLE; 1583 1584 /* 1585 * We're lying here, but rather than expose a completely new task state 1586 * to userspace, we can make this appear as if the task has gone through 1587 * a regular rt_mutex_lock() call. 1588 */ 1589 if (tsk_state & TASK_RTLOCK_WAIT) 1590 state = TASK_UNINTERRUPTIBLE; 1591 1592 return fls(state); 1593 } 1594 1595 static inline unsigned int task_state_index(struct task_struct *tsk) 1596 { 1597 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1598 } 1599 1600 static inline char task_index_to_char(unsigned int state) 1601 { 1602 static const char state_char[] = "RSDTtXZPI"; 1603 1604 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1605 1606 return state_char[state]; 1607 } 1608 1609 static inline char task_state_to_char(struct task_struct *tsk) 1610 { 1611 return task_index_to_char(task_state_index(tsk)); 1612 } 1613 1614 extern struct pid *cad_pid; 1615 1616 /* 1617 * Per process flags 1618 */ 1619 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1620 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1621 #define PF_EXITING 0x00000004 /* Getting shut down */ 1622 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1623 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1624 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1625 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1626 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1627 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1628 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1629 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1630 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */ 1631 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1632 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1633 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1634 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1635 #define PF__HOLE__00010000 0x00010000 1636 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1637 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */ 1638 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */ 1639 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1640 * I am cleaning dirty pages from some other bdi. */ 1641 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1642 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1643 #define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ 1644 #define PF_MEMALLOC_NOWARN 0x01000000 /* All allocation requests will inherit __GFP_NOWARN */ 1645 #define PF__HOLE__02000000 0x02000000 1646 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1647 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1648 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning. 1649 * See memalloc_pin_save() */ 1650 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */ 1651 #define PF__HOLE__40000000 0x40000000 1652 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1653 1654 /* 1655 * Only the _current_ task can read/write to tsk->flags, but other 1656 * tasks can access tsk->flags in readonly mode for example 1657 * with tsk_used_math (like during threaded core dumping). 1658 * There is however an exception to this rule during ptrace 1659 * or during fork: the ptracer task is allowed to write to the 1660 * child->flags of its traced child (same goes for fork, the parent 1661 * can write to the child->flags), because we're guaranteed the 1662 * child is not running and in turn not changing child->flags 1663 * at the same time the parent does it. 1664 */ 1665 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1666 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1667 #define clear_used_math() clear_stopped_child_used_math(current) 1668 #define set_used_math() set_stopped_child_used_math(current) 1669 1670 #define conditional_stopped_child_used_math(condition, child) \ 1671 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1672 1673 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1674 1675 #define copy_to_stopped_child_used_math(child) \ 1676 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1677 1678 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1679 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1680 #define used_math() tsk_used_math(current) 1681 1682 static __always_inline bool is_percpu_thread(void) 1683 { 1684 #ifdef CONFIG_SMP 1685 return (current->flags & PF_NO_SETAFFINITY) && 1686 (current->nr_cpus_allowed == 1); 1687 #else 1688 return true; 1689 #endif 1690 } 1691 1692 /* Per-process atomic flags. */ 1693 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1694 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1695 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1696 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1697 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1698 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1699 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1700 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1701 1702 #define TASK_PFA_TEST(name, func) \ 1703 static inline bool task_##func(struct task_struct *p) \ 1704 { return test_bit(PFA_##name, &p->atomic_flags); } 1705 1706 #define TASK_PFA_SET(name, func) \ 1707 static inline void task_set_##func(struct task_struct *p) \ 1708 { set_bit(PFA_##name, &p->atomic_flags); } 1709 1710 #define TASK_PFA_CLEAR(name, func) \ 1711 static inline void task_clear_##func(struct task_struct *p) \ 1712 { clear_bit(PFA_##name, &p->atomic_flags); } 1713 1714 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1715 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1716 1717 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1718 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1719 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1720 1721 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1722 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1723 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1724 1725 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1726 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1727 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1728 1729 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1730 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1731 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1732 1733 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1734 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1735 1736 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1737 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1738 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1739 1740 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1741 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1742 1743 static inline void 1744 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1745 { 1746 current->flags &= ~flags; 1747 current->flags |= orig_flags & flags; 1748 } 1749 1750 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1751 extern int task_can_attach(struct task_struct *p); 1752 extern int dl_bw_alloc(int cpu, u64 dl_bw); 1753 extern void dl_bw_free(int cpu, u64 dl_bw); 1754 #ifdef CONFIG_SMP 1755 1756 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */ 1757 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1758 1759 /** 1760 * set_cpus_allowed_ptr - set CPU affinity mask of a task 1761 * @p: the task 1762 * @new_mask: CPU affinity mask 1763 * 1764 * Return: zero if successful, or a negative error code 1765 */ 1766 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1767 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1768 extern void release_user_cpus_ptr(struct task_struct *p); 1769 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1770 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1771 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1772 #else 1773 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1774 { 1775 } 1776 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1777 { 1778 if (!cpumask_test_cpu(0, new_mask)) 1779 return -EINVAL; 1780 return 0; 1781 } 1782 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1783 { 1784 if (src->user_cpus_ptr) 1785 return -EINVAL; 1786 return 0; 1787 } 1788 static inline void release_user_cpus_ptr(struct task_struct *p) 1789 { 1790 WARN_ON(p->user_cpus_ptr); 1791 } 1792 1793 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1794 { 1795 return 0; 1796 } 1797 #endif 1798 1799 extern int yield_to(struct task_struct *p, bool preempt); 1800 extern void set_user_nice(struct task_struct *p, long nice); 1801 extern int task_prio(const struct task_struct *p); 1802 1803 /** 1804 * task_nice - return the nice value of a given task. 1805 * @p: the task in question. 1806 * 1807 * Return: The nice value [ -20 ... 0 ... 19 ]. 1808 */ 1809 static inline int task_nice(const struct task_struct *p) 1810 { 1811 return PRIO_TO_NICE((p)->static_prio); 1812 } 1813 1814 extern int can_nice(const struct task_struct *p, const int nice); 1815 extern int task_curr(const struct task_struct *p); 1816 extern int idle_cpu(int cpu); 1817 extern int available_idle_cpu(int cpu); 1818 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1819 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1820 extern void sched_set_fifo(struct task_struct *p); 1821 extern void sched_set_fifo_low(struct task_struct *p); 1822 extern void sched_set_normal(struct task_struct *p, int nice); 1823 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1824 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1825 extern struct task_struct *idle_task(int cpu); 1826 1827 /** 1828 * is_idle_task - is the specified task an idle task? 1829 * @p: the task in question. 1830 * 1831 * Return: 1 if @p is an idle task. 0 otherwise. 1832 */ 1833 static __always_inline bool is_idle_task(const struct task_struct *p) 1834 { 1835 return !!(p->flags & PF_IDLE); 1836 } 1837 1838 extern struct task_struct *curr_task(int cpu); 1839 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1840 1841 void yield(void); 1842 1843 union thread_union { 1844 struct task_struct task; 1845 #ifndef CONFIG_THREAD_INFO_IN_TASK 1846 struct thread_info thread_info; 1847 #endif 1848 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1849 }; 1850 1851 #ifndef CONFIG_THREAD_INFO_IN_TASK 1852 extern struct thread_info init_thread_info; 1853 #endif 1854 1855 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1856 1857 #ifdef CONFIG_THREAD_INFO_IN_TASK 1858 # define task_thread_info(task) (&(task)->thread_info) 1859 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1860 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1861 #endif 1862 1863 /* 1864 * find a task by one of its numerical ids 1865 * 1866 * find_task_by_pid_ns(): 1867 * finds a task by its pid in the specified namespace 1868 * find_task_by_vpid(): 1869 * finds a task by its virtual pid 1870 * 1871 * see also find_vpid() etc in include/linux/pid.h 1872 */ 1873 1874 extern struct task_struct *find_task_by_vpid(pid_t nr); 1875 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1876 1877 /* 1878 * find a task by its virtual pid and get the task struct 1879 */ 1880 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1881 1882 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1883 extern int wake_up_process(struct task_struct *tsk); 1884 extern void wake_up_new_task(struct task_struct *tsk); 1885 1886 #ifdef CONFIG_SMP 1887 extern void kick_process(struct task_struct *tsk); 1888 #else 1889 static inline void kick_process(struct task_struct *tsk) { } 1890 #endif 1891 1892 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1893 1894 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1895 { 1896 __set_task_comm(tsk, from, false); 1897 } 1898 1899 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1900 #define get_task_comm(buf, tsk) ({ \ 1901 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1902 __get_task_comm(buf, sizeof(buf), tsk); \ 1903 }) 1904 1905 #ifdef CONFIG_SMP 1906 static __always_inline void scheduler_ipi(void) 1907 { 1908 /* 1909 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1910 * TIF_NEED_RESCHED remotely (for the first time) will also send 1911 * this IPI. 1912 */ 1913 preempt_fold_need_resched(); 1914 } 1915 #else 1916 static inline void scheduler_ipi(void) { } 1917 #endif 1918 1919 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1920 1921 /* 1922 * Set thread flags in other task's structures. 1923 * See asm/thread_info.h for TIF_xxxx flags available: 1924 */ 1925 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1926 { 1927 set_ti_thread_flag(task_thread_info(tsk), flag); 1928 } 1929 1930 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1931 { 1932 clear_ti_thread_flag(task_thread_info(tsk), flag); 1933 } 1934 1935 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 1936 bool value) 1937 { 1938 update_ti_thread_flag(task_thread_info(tsk), flag, value); 1939 } 1940 1941 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1942 { 1943 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1944 } 1945 1946 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1947 { 1948 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1949 } 1950 1951 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1952 { 1953 return test_ti_thread_flag(task_thread_info(tsk), flag); 1954 } 1955 1956 static inline void set_tsk_need_resched(struct task_struct *tsk) 1957 { 1958 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1959 } 1960 1961 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1962 { 1963 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1964 } 1965 1966 static inline int test_tsk_need_resched(struct task_struct *tsk) 1967 { 1968 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 1969 } 1970 1971 /* 1972 * cond_resched() and cond_resched_lock(): latency reduction via 1973 * explicit rescheduling in places that are safe. The return 1974 * value indicates whether a reschedule was done in fact. 1975 * cond_resched_lock() will drop the spinlock before scheduling, 1976 */ 1977 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 1978 extern int __cond_resched(void); 1979 1980 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 1981 1982 void sched_dynamic_klp_enable(void); 1983 void sched_dynamic_klp_disable(void); 1984 1985 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 1986 1987 static __always_inline int _cond_resched(void) 1988 { 1989 return static_call_mod(cond_resched)(); 1990 } 1991 1992 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 1993 1994 extern int dynamic_cond_resched(void); 1995 1996 static __always_inline int _cond_resched(void) 1997 { 1998 return dynamic_cond_resched(); 1999 } 2000 2001 #else /* !CONFIG_PREEMPTION */ 2002 2003 static inline int _cond_resched(void) 2004 { 2005 klp_sched_try_switch(); 2006 return __cond_resched(); 2007 } 2008 2009 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2010 2011 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2012 2013 static inline int _cond_resched(void) 2014 { 2015 klp_sched_try_switch(); 2016 return 0; 2017 } 2018 2019 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2020 2021 #define cond_resched() ({ \ 2022 __might_resched(__FILE__, __LINE__, 0); \ 2023 _cond_resched(); \ 2024 }) 2025 2026 extern int __cond_resched_lock(spinlock_t *lock); 2027 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2028 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2029 2030 #define MIGHT_RESCHED_RCU_SHIFT 8 2031 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2032 2033 #ifndef CONFIG_PREEMPT_RT 2034 /* 2035 * Non RT kernels have an elevated preempt count due to the held lock, 2036 * but are not allowed to be inside a RCU read side critical section 2037 */ 2038 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2039 #else 2040 /* 2041 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2042 * cond_resched*lock() has to take that into account because it checks for 2043 * preempt_count() and rcu_preempt_depth(). 2044 */ 2045 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2046 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2047 #endif 2048 2049 #define cond_resched_lock(lock) ({ \ 2050 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2051 __cond_resched_lock(lock); \ 2052 }) 2053 2054 #define cond_resched_rwlock_read(lock) ({ \ 2055 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2056 __cond_resched_rwlock_read(lock); \ 2057 }) 2058 2059 #define cond_resched_rwlock_write(lock) ({ \ 2060 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2061 __cond_resched_rwlock_write(lock); \ 2062 }) 2063 2064 #ifdef CONFIG_PREEMPT_DYNAMIC 2065 2066 extern bool preempt_model_none(void); 2067 extern bool preempt_model_voluntary(void); 2068 extern bool preempt_model_full(void); 2069 2070 #else 2071 2072 static inline bool preempt_model_none(void) 2073 { 2074 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2075 } 2076 static inline bool preempt_model_voluntary(void) 2077 { 2078 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2079 } 2080 static inline bool preempt_model_full(void) 2081 { 2082 return IS_ENABLED(CONFIG_PREEMPT); 2083 } 2084 2085 #endif 2086 2087 static inline bool preempt_model_rt(void) 2088 { 2089 return IS_ENABLED(CONFIG_PREEMPT_RT); 2090 } 2091 2092 /* 2093 * Does the preemption model allow non-cooperative preemption? 2094 * 2095 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2096 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2097 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2098 * PREEMPT_NONE model. 2099 */ 2100 static inline bool preempt_model_preemptible(void) 2101 { 2102 return preempt_model_full() || preempt_model_rt(); 2103 } 2104 2105 static __always_inline bool need_resched(void) 2106 { 2107 return unlikely(tif_need_resched()); 2108 } 2109 2110 /* 2111 * Wrappers for p->thread_info->cpu access. No-op on UP. 2112 */ 2113 #ifdef CONFIG_SMP 2114 2115 static inline unsigned int task_cpu(const struct task_struct *p) 2116 { 2117 return READ_ONCE(task_thread_info(p)->cpu); 2118 } 2119 2120 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2121 2122 #else 2123 2124 static inline unsigned int task_cpu(const struct task_struct *p) 2125 { 2126 return 0; 2127 } 2128 2129 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2130 { 2131 } 2132 2133 #endif /* CONFIG_SMP */ 2134 2135 extern bool sched_task_on_rq(struct task_struct *p); 2136 extern unsigned long get_wchan(struct task_struct *p); 2137 extern struct task_struct *cpu_curr_snapshot(int cpu); 2138 2139 #include <linux/spinlock.h> 2140 2141 /* 2142 * In order to reduce various lock holder preemption latencies provide an 2143 * interface to see if a vCPU is currently running or not. 2144 * 2145 * This allows us to terminate optimistic spin loops and block, analogous to 2146 * the native optimistic spin heuristic of testing if the lock owner task is 2147 * running or not. 2148 */ 2149 #ifndef vcpu_is_preempted 2150 static inline bool vcpu_is_preempted(int cpu) 2151 { 2152 return false; 2153 } 2154 #endif 2155 2156 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2157 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2158 2159 #ifndef TASK_SIZE_OF 2160 #define TASK_SIZE_OF(tsk) TASK_SIZE 2161 #endif 2162 2163 #ifdef CONFIG_SMP 2164 static inline bool owner_on_cpu(struct task_struct *owner) 2165 { 2166 /* 2167 * As lock holder preemption issue, we both skip spinning if 2168 * task is not on cpu or its cpu is preempted 2169 */ 2170 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2171 } 2172 2173 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2174 unsigned long sched_cpu_util(int cpu); 2175 #endif /* CONFIG_SMP */ 2176 2177 #ifdef CONFIG_SCHED_CORE 2178 extern void sched_core_free(struct task_struct *tsk); 2179 extern void sched_core_fork(struct task_struct *p); 2180 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2181 unsigned long uaddr); 2182 extern int sched_core_idle_cpu(int cpu); 2183 #else 2184 static inline void sched_core_free(struct task_struct *tsk) { } 2185 static inline void sched_core_fork(struct task_struct *p) { } 2186 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); } 2187 #endif 2188 2189 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2190 2191 #endif 2192