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_types.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/netdevice_xmit.h> 40 #include <linux/task_io_accounting.h> 41 #include <linux/posix-timers_types.h> 42 #include <linux/restart_block.h> 43 #include <uapi/linux/rseq.h> 44 #include <linux/seqlock_types.h> 45 #include <linux/kcsan.h> 46 #include <linux/rv.h> 47 #include <linux/livepatch_sched.h> 48 #include <linux/uidgid_types.h> 49 #include <asm/kmap_size.h> 50 51 /* task_struct member predeclarations (sorted alphabetically): */ 52 struct audit_context; 53 struct bio_list; 54 struct blk_plug; 55 struct bpf_local_storage; 56 struct bpf_run_ctx; 57 struct bpf_net_context; 58 struct capture_control; 59 struct cfs_rq; 60 struct fs_struct; 61 struct futex_pi_state; 62 struct io_context; 63 struct io_uring_task; 64 struct mempolicy; 65 struct nameidata; 66 struct nsproxy; 67 struct perf_event_context; 68 struct pid_namespace; 69 struct pipe_inode_info; 70 struct rcu_node; 71 struct reclaim_state; 72 struct robust_list_head; 73 struct root_domain; 74 struct rq; 75 struct sched_attr; 76 struct sched_dl_entity; 77 struct seq_file; 78 struct sighand_struct; 79 struct signal_struct; 80 struct task_delay_info; 81 struct task_group; 82 struct task_struct; 83 struct user_event_mm; 84 85 #include <linux/sched/ext.h> 86 87 /* 88 * Task state bitmask. NOTE! These bits are also 89 * encoded in fs/proc/array.c: get_task_state(). 90 * 91 * We have two separate sets of flags: task->__state 92 * is about runnability, while task->exit_state are 93 * about the task exiting. Confusing, but this way 94 * modifying one set can't modify the other one by 95 * mistake. 96 */ 97 98 /* Used in tsk->__state: */ 99 #define TASK_RUNNING 0x00000000 100 #define TASK_INTERRUPTIBLE 0x00000001 101 #define TASK_UNINTERRUPTIBLE 0x00000002 102 #define __TASK_STOPPED 0x00000004 103 #define __TASK_TRACED 0x00000008 104 /* Used in tsk->exit_state: */ 105 #define EXIT_DEAD 0x00000010 106 #define EXIT_ZOMBIE 0x00000020 107 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 108 /* Used in tsk->__state again: */ 109 #define TASK_PARKED 0x00000040 110 #define TASK_DEAD 0x00000080 111 #define TASK_WAKEKILL 0x00000100 112 #define TASK_WAKING 0x00000200 113 #define TASK_NOLOAD 0x00000400 114 #define TASK_NEW 0x00000800 115 #define TASK_RTLOCK_WAIT 0x00001000 116 #define TASK_FREEZABLE 0x00002000 117 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 118 #define TASK_FROZEN 0x00008000 119 #define TASK_STATE_MAX 0x00010000 120 121 #define TASK_ANY (TASK_STATE_MAX-1) 122 123 /* 124 * DO NOT ADD ANY NEW USERS ! 125 */ 126 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 127 128 /* Convenience macros for the sake of set_current_state: */ 129 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 130 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 131 #define TASK_TRACED __TASK_TRACED 132 133 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 134 135 /* Convenience macros for the sake of wake_up(): */ 136 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 137 138 /* get_task_state(): */ 139 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 140 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 141 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 142 TASK_PARKED) 143 144 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 145 146 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 147 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 148 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 149 150 /* 151 * Special states are those that do not use the normal wait-loop pattern. See 152 * the comment with set_special_state(). 153 */ 154 #define is_special_task_state(state) \ 155 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | \ 156 TASK_DEAD | TASK_FROZEN)) 157 158 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 159 # define debug_normal_state_change(state_value) \ 160 do { \ 161 WARN_ON_ONCE(is_special_task_state(state_value)); \ 162 current->task_state_change = _THIS_IP_; \ 163 } while (0) 164 165 # define debug_special_state_change(state_value) \ 166 do { \ 167 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 168 current->task_state_change = _THIS_IP_; \ 169 } while (0) 170 171 # define debug_rtlock_wait_set_state() \ 172 do { \ 173 current->saved_state_change = current->task_state_change;\ 174 current->task_state_change = _THIS_IP_; \ 175 } while (0) 176 177 # define debug_rtlock_wait_restore_state() \ 178 do { \ 179 current->task_state_change = current->saved_state_change;\ 180 } while (0) 181 182 #else 183 # define debug_normal_state_change(cond) do { } while (0) 184 # define debug_special_state_change(cond) do { } while (0) 185 # define debug_rtlock_wait_set_state() do { } while (0) 186 # define debug_rtlock_wait_restore_state() do { } while (0) 187 #endif 188 189 /* 190 * set_current_state() includes a barrier so that the write of current->__state 191 * is correctly serialised wrt the caller's subsequent test of whether to 192 * actually sleep: 193 * 194 * for (;;) { 195 * set_current_state(TASK_UNINTERRUPTIBLE); 196 * if (CONDITION) 197 * break; 198 * 199 * schedule(); 200 * } 201 * __set_current_state(TASK_RUNNING); 202 * 203 * If the caller does not need such serialisation (because, for instance, the 204 * CONDITION test and condition change and wakeup are under the same lock) then 205 * use __set_current_state(). 206 * 207 * The above is typically ordered against the wakeup, which does: 208 * 209 * CONDITION = 1; 210 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 211 * 212 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 213 * accessing p->__state. 214 * 215 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is, 216 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 217 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 218 * 219 * However, with slightly different timing the wakeup TASK_RUNNING store can 220 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 221 * a problem either because that will result in one extra go around the loop 222 * and our @cond test will save the day. 223 * 224 * Also see the comments of try_to_wake_up(). 225 */ 226 #define __set_current_state(state_value) \ 227 do { \ 228 debug_normal_state_change((state_value)); \ 229 WRITE_ONCE(current->__state, (state_value)); \ 230 } while (0) 231 232 #define set_current_state(state_value) \ 233 do { \ 234 debug_normal_state_change((state_value)); \ 235 smp_store_mb(current->__state, (state_value)); \ 236 } while (0) 237 238 /* 239 * set_special_state() should be used for those states when the blocking task 240 * can not use the regular condition based wait-loop. In that case we must 241 * serialize against wakeups such that any possible in-flight TASK_RUNNING 242 * stores will not collide with our state change. 243 */ 244 #define set_special_state(state_value) \ 245 do { \ 246 unsigned long flags; /* may shadow */ \ 247 \ 248 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 249 debug_special_state_change((state_value)); \ 250 WRITE_ONCE(current->__state, (state_value)); \ 251 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 252 } while (0) 253 254 /* 255 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 256 * 257 * RT's spin/rwlock substitutions are state preserving. The state of the 258 * task when blocking on the lock is saved in task_struct::saved_state and 259 * restored after the lock has been acquired. These operations are 260 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 261 * lock related wakeups while the task is blocked on the lock are 262 * redirected to operate on task_struct::saved_state to ensure that these 263 * are not dropped. On restore task_struct::saved_state is set to 264 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 265 * 266 * The lock operation looks like this: 267 * 268 * current_save_and_set_rtlock_wait_state(); 269 * for (;;) { 270 * if (try_lock()) 271 * break; 272 * raw_spin_unlock_irq(&lock->wait_lock); 273 * schedule_rtlock(); 274 * raw_spin_lock_irq(&lock->wait_lock); 275 * set_current_state(TASK_RTLOCK_WAIT); 276 * } 277 * current_restore_rtlock_saved_state(); 278 */ 279 #define current_save_and_set_rtlock_wait_state() \ 280 do { \ 281 lockdep_assert_irqs_disabled(); \ 282 raw_spin_lock(¤t->pi_lock); \ 283 current->saved_state = current->__state; \ 284 debug_rtlock_wait_set_state(); \ 285 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 286 raw_spin_unlock(¤t->pi_lock); \ 287 } while (0); 288 289 #define current_restore_rtlock_saved_state() \ 290 do { \ 291 lockdep_assert_irqs_disabled(); \ 292 raw_spin_lock(¤t->pi_lock); \ 293 debug_rtlock_wait_restore_state(); \ 294 WRITE_ONCE(current->__state, current->saved_state); \ 295 current->saved_state = TASK_RUNNING; \ 296 raw_spin_unlock(¤t->pi_lock); \ 297 } while (0); 298 299 #define get_current_state() READ_ONCE(current->__state) 300 301 /* 302 * Define the task command name length as enum, then it can be visible to 303 * BPF programs. 304 */ 305 enum { 306 TASK_COMM_LEN = 16, 307 }; 308 309 extern void sched_tick(void); 310 311 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 312 313 extern long schedule_timeout(long timeout); 314 extern long schedule_timeout_interruptible(long timeout); 315 extern long schedule_timeout_killable(long timeout); 316 extern long schedule_timeout_uninterruptible(long timeout); 317 extern long schedule_timeout_idle(long timeout); 318 asmlinkage void schedule(void); 319 extern void schedule_preempt_disabled(void); 320 asmlinkage void preempt_schedule_irq(void); 321 #ifdef CONFIG_PREEMPT_RT 322 extern void schedule_rtlock(void); 323 #endif 324 325 extern int __must_check io_schedule_prepare(void); 326 extern void io_schedule_finish(int token); 327 extern long io_schedule_timeout(long timeout); 328 extern void io_schedule(void); 329 330 /** 331 * struct prev_cputime - snapshot of system and user cputime 332 * @utime: time spent in user mode 333 * @stime: time spent in system mode 334 * @lock: protects the above two fields 335 * 336 * Stores previous user/system time values such that we can guarantee 337 * monotonicity. 338 */ 339 struct prev_cputime { 340 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 341 u64 utime; 342 u64 stime; 343 raw_spinlock_t lock; 344 #endif 345 }; 346 347 enum vtime_state { 348 /* Task is sleeping or running in a CPU with VTIME inactive: */ 349 VTIME_INACTIVE = 0, 350 /* Task is idle */ 351 VTIME_IDLE, 352 /* Task runs in kernelspace in a CPU with VTIME active: */ 353 VTIME_SYS, 354 /* Task runs in userspace in a CPU with VTIME active: */ 355 VTIME_USER, 356 /* Task runs as guests in a CPU with VTIME active: */ 357 VTIME_GUEST, 358 }; 359 360 struct vtime { 361 seqcount_t seqcount; 362 unsigned long long starttime; 363 enum vtime_state state; 364 unsigned int cpu; 365 u64 utime; 366 u64 stime; 367 u64 gtime; 368 }; 369 370 /* 371 * Utilization clamp constraints. 372 * @UCLAMP_MIN: Minimum utilization 373 * @UCLAMP_MAX: Maximum utilization 374 * @UCLAMP_CNT: Utilization clamp constraints count 375 */ 376 enum uclamp_id { 377 UCLAMP_MIN = 0, 378 UCLAMP_MAX, 379 UCLAMP_CNT 380 }; 381 382 #ifdef CONFIG_SMP 383 extern struct root_domain def_root_domain; 384 extern struct mutex sched_domains_mutex; 385 #endif 386 387 struct sched_param { 388 int sched_priority; 389 }; 390 391 struct sched_info { 392 #ifdef CONFIG_SCHED_INFO 393 /* Cumulative counters: */ 394 395 /* # of times we have run on this CPU: */ 396 unsigned long pcount; 397 398 /* Time spent waiting on a runqueue: */ 399 unsigned long long run_delay; 400 401 /* Max time spent waiting on a runqueue: */ 402 unsigned long long max_run_delay; 403 404 /* Min time spent waiting on a runqueue: */ 405 unsigned long long min_run_delay; 406 407 /* Timestamps: */ 408 409 /* When did we last run on a CPU? */ 410 unsigned long long last_arrival; 411 412 /* When were we last queued to run? */ 413 unsigned long long last_queued; 414 415 #endif /* CONFIG_SCHED_INFO */ 416 }; 417 418 /* 419 * Integer metrics need fixed point arithmetic, e.g., sched/fair 420 * has a few: load, load_avg, util_avg, freq, and capacity. 421 * 422 * We define a basic fixed point arithmetic range, and then formalize 423 * all these metrics based on that basic range. 424 */ 425 # define SCHED_FIXEDPOINT_SHIFT 10 426 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 427 428 /* Increase resolution of cpu_capacity calculations */ 429 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 430 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 431 432 struct load_weight { 433 unsigned long weight; 434 u32 inv_weight; 435 }; 436 437 /* 438 * The load/runnable/util_avg accumulates an infinite geometric series 439 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 440 * 441 * [load_avg definition] 442 * 443 * load_avg = runnable% * scale_load_down(load) 444 * 445 * [runnable_avg definition] 446 * 447 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 448 * 449 * [util_avg definition] 450 * 451 * util_avg = running% * SCHED_CAPACITY_SCALE 452 * 453 * where runnable% is the time ratio that a sched_entity is runnable and 454 * running% the time ratio that a sched_entity is running. 455 * 456 * For cfs_rq, they are the aggregated values of all runnable and blocked 457 * sched_entities. 458 * 459 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 460 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 461 * for computing those signals (see update_rq_clock_pelt()) 462 * 463 * N.B., the above ratios (runnable% and running%) themselves are in the 464 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 465 * to as large a range as necessary. This is for example reflected by 466 * util_avg's SCHED_CAPACITY_SCALE. 467 * 468 * [Overflow issue] 469 * 470 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 471 * with the highest load (=88761), always runnable on a single cfs_rq, 472 * and should not overflow as the number already hits PID_MAX_LIMIT. 473 * 474 * For all other cases (including 32-bit kernels), struct load_weight's 475 * weight will overflow first before we do, because: 476 * 477 * Max(load_avg) <= Max(load.weight) 478 * 479 * Then it is the load_weight's responsibility to consider overflow 480 * issues. 481 */ 482 struct sched_avg { 483 u64 last_update_time; 484 u64 load_sum; 485 u64 runnable_sum; 486 u32 util_sum; 487 u32 period_contrib; 488 unsigned long load_avg; 489 unsigned long runnable_avg; 490 unsigned long util_avg; 491 unsigned int util_est; 492 } ____cacheline_aligned; 493 494 /* 495 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 496 * updates. When a task is dequeued, its util_est should not be updated if its 497 * util_avg has not been updated in the meantime. 498 * This information is mapped into the MSB bit of util_est at dequeue time. 499 * Since max value of util_est for a task is 1024 (PELT util_avg for a task) 500 * it is safe to use MSB. 501 */ 502 #define UTIL_EST_WEIGHT_SHIFT 2 503 #define UTIL_AVG_UNCHANGED 0x80000000 504 505 struct sched_statistics { 506 #ifdef CONFIG_SCHEDSTATS 507 u64 wait_start; 508 u64 wait_max; 509 u64 wait_count; 510 u64 wait_sum; 511 u64 iowait_count; 512 u64 iowait_sum; 513 514 u64 sleep_start; 515 u64 sleep_max; 516 s64 sum_sleep_runtime; 517 518 u64 block_start; 519 u64 block_max; 520 s64 sum_block_runtime; 521 522 s64 exec_max; 523 u64 slice_max; 524 525 u64 nr_migrations_cold; 526 u64 nr_failed_migrations_affine; 527 u64 nr_failed_migrations_running; 528 u64 nr_failed_migrations_hot; 529 u64 nr_forced_migrations; 530 531 u64 nr_wakeups; 532 u64 nr_wakeups_sync; 533 u64 nr_wakeups_migrate; 534 u64 nr_wakeups_local; 535 u64 nr_wakeups_remote; 536 u64 nr_wakeups_affine; 537 u64 nr_wakeups_affine_attempts; 538 u64 nr_wakeups_passive; 539 u64 nr_wakeups_idle; 540 541 #ifdef CONFIG_SCHED_CORE 542 u64 core_forceidle_sum; 543 #endif 544 #endif /* CONFIG_SCHEDSTATS */ 545 } ____cacheline_aligned; 546 547 struct sched_entity { 548 /* For load-balancing: */ 549 struct load_weight load; 550 struct rb_node run_node; 551 u64 deadline; 552 u64 min_vruntime; 553 u64 min_slice; 554 555 struct list_head group_node; 556 unsigned char on_rq; 557 unsigned char sched_delayed; 558 unsigned char rel_deadline; 559 unsigned char custom_slice; 560 /* hole */ 561 562 u64 exec_start; 563 u64 sum_exec_runtime; 564 u64 prev_sum_exec_runtime; 565 u64 vruntime; 566 s64 vlag; 567 u64 slice; 568 569 u64 nr_migrations; 570 571 #ifdef CONFIG_FAIR_GROUP_SCHED 572 int depth; 573 struct sched_entity *parent; 574 /* rq on which this entity is (to be) queued: */ 575 struct cfs_rq *cfs_rq; 576 /* rq "owned" by this entity/group: */ 577 struct cfs_rq *my_q; 578 /* cached value of my_q->h_nr_running */ 579 unsigned long runnable_weight; 580 #endif 581 582 #ifdef CONFIG_SMP 583 /* 584 * Per entity load average tracking. 585 * 586 * Put into separate cache line so it does not 587 * collide with read-mostly values above. 588 */ 589 struct sched_avg avg; 590 #endif 591 }; 592 593 struct sched_rt_entity { 594 struct list_head run_list; 595 unsigned long timeout; 596 unsigned long watchdog_stamp; 597 unsigned int time_slice; 598 unsigned short on_rq; 599 unsigned short on_list; 600 601 struct sched_rt_entity *back; 602 #ifdef CONFIG_RT_GROUP_SCHED 603 struct sched_rt_entity *parent; 604 /* rq on which this entity is (to be) queued: */ 605 struct rt_rq *rt_rq; 606 /* rq "owned" by this entity/group: */ 607 struct rt_rq *my_q; 608 #endif 609 } __randomize_layout; 610 611 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *); 612 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *); 613 614 struct sched_dl_entity { 615 struct rb_node rb_node; 616 617 /* 618 * Original scheduling parameters. Copied here from sched_attr 619 * during sched_setattr(), they will remain the same until 620 * the next sched_setattr(). 621 */ 622 u64 dl_runtime; /* Maximum runtime for each instance */ 623 u64 dl_deadline; /* Relative deadline of each instance */ 624 u64 dl_period; /* Separation of two instances (period) */ 625 u64 dl_bw; /* dl_runtime / dl_period */ 626 u64 dl_density; /* dl_runtime / dl_deadline */ 627 628 /* 629 * Actual scheduling parameters. Initialized with the values above, 630 * they are continuously updated during task execution. Note that 631 * the remaining runtime could be < 0 in case we are in overrun. 632 */ 633 s64 runtime; /* Remaining runtime for this instance */ 634 u64 deadline; /* Absolute deadline for this instance */ 635 unsigned int flags; /* Specifying the scheduler behaviour */ 636 637 /* 638 * Some bool flags: 639 * 640 * @dl_throttled tells if we exhausted the runtime. If so, the 641 * task has to wait for a replenishment to be performed at the 642 * next firing of dl_timer. 643 * 644 * @dl_yielded tells if task gave up the CPU before consuming 645 * all its available runtime during the last job. 646 * 647 * @dl_non_contending tells if the task is inactive while still 648 * contributing to the active utilization. In other words, it 649 * indicates if the inactive timer has been armed and its handler 650 * has not been executed yet. This flag is useful to avoid race 651 * conditions between the inactive timer handler and the wakeup 652 * code. 653 * 654 * @dl_overrun tells if the task asked to be informed about runtime 655 * overruns. 656 * 657 * @dl_server tells if this is a server entity. 658 * 659 * @dl_defer tells if this is a deferred or regular server. For 660 * now only defer server exists. 661 * 662 * @dl_defer_armed tells if the deferrable server is waiting 663 * for the replenishment timer to activate it. 664 * 665 * @dl_server_active tells if the dlserver is active(started). 666 * dlserver is started on first cfs enqueue on an idle runqueue 667 * and is stopped when a dequeue results in 0 cfs tasks on the 668 * runqueue. In other words, dlserver is active only when cpu's 669 * runqueue has atleast one cfs task. 670 * 671 * @dl_defer_running tells if the deferrable server is actually 672 * running, skipping the defer phase. 673 */ 674 unsigned int dl_throttled : 1; 675 unsigned int dl_yielded : 1; 676 unsigned int dl_non_contending : 1; 677 unsigned int dl_overrun : 1; 678 unsigned int dl_server : 1; 679 unsigned int dl_server_active : 1; 680 unsigned int dl_defer : 1; 681 unsigned int dl_defer_armed : 1; 682 unsigned int dl_defer_running : 1; 683 684 /* 685 * Bandwidth enforcement timer. Each -deadline task has its 686 * own bandwidth to be enforced, thus we need one timer per task. 687 */ 688 struct hrtimer dl_timer; 689 690 /* 691 * Inactive timer, responsible for decreasing the active utilization 692 * at the "0-lag time". When a -deadline task blocks, it contributes 693 * to GRUB's active utilization until the "0-lag time", hence a 694 * timer is needed to decrease the active utilization at the correct 695 * time. 696 */ 697 struct hrtimer inactive_timer; 698 699 /* 700 * Bits for DL-server functionality. Also see the comment near 701 * dl_server_update(). 702 * 703 * @rq the runqueue this server is for 704 * 705 * @server_has_tasks() returns true if @server_pick return a 706 * runnable task. 707 */ 708 struct rq *rq; 709 dl_server_has_tasks_f server_has_tasks; 710 dl_server_pick_f server_pick_task; 711 712 #ifdef CONFIG_RT_MUTEXES 713 /* 714 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 715 * pi_se points to the donor, otherwise points to the dl_se it belongs 716 * to (the original one/itself). 717 */ 718 struct sched_dl_entity *pi_se; 719 #endif 720 }; 721 722 #ifdef CONFIG_UCLAMP_TASK 723 /* Number of utilization clamp buckets (shorter alias) */ 724 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 725 726 /* 727 * Utilization clamp for a scheduling entity 728 * @value: clamp value "assigned" to a se 729 * @bucket_id: bucket index corresponding to the "assigned" value 730 * @active: the se is currently refcounted in a rq's bucket 731 * @user_defined: the requested clamp value comes from user-space 732 * 733 * The bucket_id is the index of the clamp bucket matching the clamp value 734 * which is pre-computed and stored to avoid expensive integer divisions from 735 * the fast path. 736 * 737 * The active bit is set whenever a task has got an "effective" value assigned, 738 * which can be different from the clamp value "requested" from user-space. 739 * This allows to know a task is refcounted in the rq's bucket corresponding 740 * to the "effective" bucket_id. 741 * 742 * The user_defined bit is set whenever a task has got a task-specific clamp 743 * value requested from userspace, i.e. the system defaults apply to this task 744 * just as a restriction. This allows to relax default clamps when a less 745 * restrictive task-specific value has been requested, thus allowing to 746 * implement a "nice" semantic. For example, a task running with a 20% 747 * default boost can still drop its own boosting to 0%. 748 */ 749 struct uclamp_se { 750 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 751 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 752 unsigned int active : 1; 753 unsigned int user_defined : 1; 754 }; 755 #endif /* CONFIG_UCLAMP_TASK */ 756 757 union rcu_special { 758 struct { 759 u8 blocked; 760 u8 need_qs; 761 u8 exp_hint; /* Hint for performance. */ 762 u8 need_mb; /* Readers need smp_mb(). */ 763 } b; /* Bits. */ 764 u32 s; /* Set of bits. */ 765 }; 766 767 enum perf_event_task_context { 768 perf_invalid_context = -1, 769 perf_hw_context = 0, 770 perf_sw_context, 771 perf_nr_task_contexts, 772 }; 773 774 /* 775 * Number of contexts where an event can trigger: 776 * task, softirq, hardirq, nmi. 777 */ 778 #define PERF_NR_CONTEXTS 4 779 780 struct wake_q_node { 781 struct wake_q_node *next; 782 }; 783 784 struct kmap_ctrl { 785 #ifdef CONFIG_KMAP_LOCAL 786 int idx; 787 pte_t pteval[KM_MAX_IDX]; 788 #endif 789 }; 790 791 struct task_struct { 792 #ifdef CONFIG_THREAD_INFO_IN_TASK 793 /* 794 * For reasons of header soup (see current_thread_info()), this 795 * must be the first element of task_struct. 796 */ 797 struct thread_info thread_info; 798 #endif 799 unsigned int __state; 800 801 /* saved state for "spinlock sleepers" */ 802 unsigned int saved_state; 803 804 /* 805 * This begins the randomizable portion of task_struct. Only 806 * scheduling-critical items should be added above here. 807 */ 808 randomized_struct_fields_start 809 810 void *stack; 811 refcount_t usage; 812 /* Per task flags (PF_*), defined further below: */ 813 unsigned int flags; 814 unsigned int ptrace; 815 816 #ifdef CONFIG_MEM_ALLOC_PROFILING 817 struct alloc_tag *alloc_tag; 818 #endif 819 820 #ifdef CONFIG_SMP 821 int on_cpu; 822 struct __call_single_node wake_entry; 823 unsigned int wakee_flips; 824 unsigned long wakee_flip_decay_ts; 825 struct task_struct *last_wakee; 826 827 /* 828 * recent_used_cpu is initially set as the last CPU used by a task 829 * that wakes affine another task. Waker/wakee relationships can 830 * push tasks around a CPU where each wakeup moves to the next one. 831 * Tracking a recently used CPU allows a quick search for a recently 832 * used CPU that may be idle. 833 */ 834 int recent_used_cpu; 835 int wake_cpu; 836 #endif 837 int on_rq; 838 839 int prio; 840 int static_prio; 841 int normal_prio; 842 unsigned int rt_priority; 843 844 struct sched_entity se; 845 struct sched_rt_entity rt; 846 struct sched_dl_entity dl; 847 struct sched_dl_entity *dl_server; 848 #ifdef CONFIG_SCHED_CLASS_EXT 849 struct sched_ext_entity scx; 850 #endif 851 const struct sched_class *sched_class; 852 853 #ifdef CONFIG_SCHED_CORE 854 struct rb_node core_node; 855 unsigned long core_cookie; 856 unsigned int core_occupation; 857 #endif 858 859 #ifdef CONFIG_CGROUP_SCHED 860 struct task_group *sched_task_group; 861 #endif 862 863 864 #ifdef CONFIG_UCLAMP_TASK 865 /* 866 * Clamp values requested for a scheduling entity. 867 * Must be updated with task_rq_lock() held. 868 */ 869 struct uclamp_se uclamp_req[UCLAMP_CNT]; 870 /* 871 * Effective clamp values used for a scheduling entity. 872 * Must be updated with task_rq_lock() held. 873 */ 874 struct uclamp_se uclamp[UCLAMP_CNT]; 875 #endif 876 877 struct sched_statistics stats; 878 879 #ifdef CONFIG_PREEMPT_NOTIFIERS 880 /* List of struct preempt_notifier: */ 881 struct hlist_head preempt_notifiers; 882 #endif 883 884 #ifdef CONFIG_BLK_DEV_IO_TRACE 885 unsigned int btrace_seq; 886 #endif 887 888 unsigned int policy; 889 unsigned long max_allowed_capacity; 890 int nr_cpus_allowed; 891 const cpumask_t *cpus_ptr; 892 cpumask_t *user_cpus_ptr; 893 cpumask_t cpus_mask; 894 void *migration_pending; 895 #ifdef CONFIG_SMP 896 unsigned short migration_disabled; 897 #endif 898 unsigned short migration_flags; 899 900 #ifdef CONFIG_PREEMPT_RCU 901 int rcu_read_lock_nesting; 902 union rcu_special rcu_read_unlock_special; 903 struct list_head rcu_node_entry; 904 struct rcu_node *rcu_blocked_node; 905 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 906 907 #ifdef CONFIG_TASKS_RCU 908 unsigned long rcu_tasks_nvcsw; 909 u8 rcu_tasks_holdout; 910 u8 rcu_tasks_idx; 911 int rcu_tasks_idle_cpu; 912 struct list_head rcu_tasks_holdout_list; 913 int rcu_tasks_exit_cpu; 914 struct list_head rcu_tasks_exit_list; 915 #endif /* #ifdef CONFIG_TASKS_RCU */ 916 917 #ifdef CONFIG_TASKS_TRACE_RCU 918 int trc_reader_nesting; 919 int trc_ipi_to_cpu; 920 union rcu_special trc_reader_special; 921 struct list_head trc_holdout_list; 922 struct list_head trc_blkd_node; 923 int trc_blkd_cpu; 924 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 925 926 struct sched_info sched_info; 927 928 struct list_head tasks; 929 #ifdef CONFIG_SMP 930 struct plist_node pushable_tasks; 931 struct rb_node pushable_dl_tasks; 932 #endif 933 934 struct mm_struct *mm; 935 struct mm_struct *active_mm; 936 struct address_space *faults_disabled_mapping; 937 938 int exit_state; 939 int exit_code; 940 int exit_signal; 941 /* The signal sent when the parent dies: */ 942 int pdeath_signal; 943 /* JOBCTL_*, siglock protected: */ 944 unsigned long jobctl; 945 946 /* Used for emulating ABI behavior of previous Linux versions: */ 947 unsigned int personality; 948 949 /* Scheduler bits, serialized by scheduler locks: */ 950 unsigned sched_reset_on_fork:1; 951 unsigned sched_contributes_to_load:1; 952 unsigned sched_migrated:1; 953 unsigned sched_task_hot:1; 954 955 /* Force alignment to the next boundary: */ 956 unsigned :0; 957 958 /* Unserialized, strictly 'current' */ 959 960 /* 961 * This field must not be in the scheduler word above due to wakelist 962 * queueing no longer being serialized by p->on_cpu. However: 963 * 964 * p->XXX = X; ttwu() 965 * schedule() if (p->on_rq && ..) // false 966 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 967 * deactivate_task() ttwu_queue_wakelist()) 968 * p->on_rq = 0; p->sched_remote_wakeup = Y; 969 * 970 * guarantees all stores of 'current' are visible before 971 * ->sched_remote_wakeup gets used, so it can be in this word. 972 */ 973 unsigned sched_remote_wakeup:1; 974 #ifdef CONFIG_RT_MUTEXES 975 unsigned sched_rt_mutex:1; 976 #endif 977 978 /* Bit to tell TOMOYO we're in execve(): */ 979 unsigned in_execve:1; 980 unsigned in_iowait:1; 981 #ifndef TIF_RESTORE_SIGMASK 982 unsigned restore_sigmask:1; 983 #endif 984 #ifdef CONFIG_MEMCG_V1 985 unsigned in_user_fault:1; 986 #endif 987 #ifdef CONFIG_LRU_GEN 988 /* whether the LRU algorithm may apply to this access */ 989 unsigned in_lru_fault:1; 990 #endif 991 #ifdef CONFIG_COMPAT_BRK 992 unsigned brk_randomized:1; 993 #endif 994 #ifdef CONFIG_CGROUPS 995 /* disallow userland-initiated cgroup migration */ 996 unsigned no_cgroup_migration:1; 997 /* task is frozen/stopped (used by the cgroup freezer) */ 998 unsigned frozen:1; 999 #endif 1000 #ifdef CONFIG_BLK_CGROUP 1001 unsigned use_memdelay:1; 1002 #endif 1003 #ifdef CONFIG_PSI 1004 /* Stalled due to lack of memory */ 1005 unsigned in_memstall:1; 1006 #endif 1007 #ifdef CONFIG_PAGE_OWNER 1008 /* Used by page_owner=on to detect recursion in page tracking. */ 1009 unsigned in_page_owner:1; 1010 #endif 1011 #ifdef CONFIG_EVENTFD 1012 /* Recursion prevention for eventfd_signal() */ 1013 unsigned in_eventfd:1; 1014 #endif 1015 #ifdef CONFIG_ARCH_HAS_CPU_PASID 1016 unsigned pasid_activated:1; 1017 #endif 1018 #ifdef CONFIG_X86_BUS_LOCK_DETECT 1019 unsigned reported_split_lock:1; 1020 #endif 1021 #ifdef CONFIG_TASK_DELAY_ACCT 1022 /* delay due to memory thrashing */ 1023 unsigned in_thrashing:1; 1024 #endif 1025 #ifdef CONFIG_PREEMPT_RT 1026 struct netdev_xmit net_xmit; 1027 #endif 1028 unsigned long atomic_flags; /* Flags requiring atomic access. */ 1029 1030 struct restart_block restart_block; 1031 1032 pid_t pid; 1033 pid_t tgid; 1034 1035 #ifdef CONFIG_STACKPROTECTOR 1036 /* Canary value for the -fstack-protector GCC feature: */ 1037 unsigned long stack_canary; 1038 #endif 1039 /* 1040 * Pointers to the (original) parent process, youngest child, younger sibling, 1041 * older sibling, respectively. (p->father can be replaced with 1042 * p->real_parent->pid) 1043 */ 1044 1045 /* Real parent process: */ 1046 struct task_struct __rcu *real_parent; 1047 1048 /* Recipient of SIGCHLD, wait4() reports: */ 1049 struct task_struct __rcu *parent; 1050 1051 /* 1052 * Children/sibling form the list of natural children: 1053 */ 1054 struct list_head children; 1055 struct list_head sibling; 1056 struct task_struct *group_leader; 1057 1058 /* 1059 * 'ptraced' is the list of tasks this task is using ptrace() on. 1060 * 1061 * This includes both natural children and PTRACE_ATTACH targets. 1062 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 1063 */ 1064 struct list_head ptraced; 1065 struct list_head ptrace_entry; 1066 1067 /* PID/PID hash table linkage. */ 1068 struct pid *thread_pid; 1069 struct hlist_node pid_links[PIDTYPE_MAX]; 1070 struct list_head thread_node; 1071 1072 struct completion *vfork_done; 1073 1074 /* CLONE_CHILD_SETTID: */ 1075 int __user *set_child_tid; 1076 1077 /* CLONE_CHILD_CLEARTID: */ 1078 int __user *clear_child_tid; 1079 1080 /* PF_KTHREAD | PF_IO_WORKER */ 1081 void *worker_private; 1082 1083 u64 utime; 1084 u64 stime; 1085 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1086 u64 utimescaled; 1087 u64 stimescaled; 1088 #endif 1089 u64 gtime; 1090 struct prev_cputime prev_cputime; 1091 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1092 struct vtime vtime; 1093 #endif 1094 1095 #ifdef CONFIG_NO_HZ_FULL 1096 atomic_t tick_dep_mask; 1097 #endif 1098 /* Context switch counts: */ 1099 unsigned long nvcsw; 1100 unsigned long nivcsw; 1101 1102 /* Monotonic time in nsecs: */ 1103 u64 start_time; 1104 1105 /* Boot based time in nsecs: */ 1106 u64 start_boottime; 1107 1108 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1109 unsigned long min_flt; 1110 unsigned long maj_flt; 1111 1112 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1113 struct posix_cputimers posix_cputimers; 1114 1115 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1116 struct posix_cputimers_work posix_cputimers_work; 1117 #endif 1118 1119 /* Process credentials: */ 1120 1121 /* Tracer's credentials at attach: */ 1122 const struct cred __rcu *ptracer_cred; 1123 1124 /* Objective and real subjective task credentials (COW): */ 1125 const struct cred __rcu *real_cred; 1126 1127 /* Effective (overridable) subjective task credentials (COW): */ 1128 const struct cred __rcu *cred; 1129 1130 #ifdef CONFIG_KEYS 1131 /* Cached requested key. */ 1132 struct key *cached_requested_key; 1133 #endif 1134 1135 /* 1136 * executable name, excluding path. 1137 * 1138 * - normally initialized begin_new_exec() 1139 * - set it with set_task_comm() 1140 * - strscpy_pad() to ensure it is always NUL-terminated and 1141 * zero-padded 1142 * - task_lock() to ensure the operation is atomic and the name is 1143 * fully updated. 1144 */ 1145 char comm[TASK_COMM_LEN]; 1146 1147 struct nameidata *nameidata; 1148 1149 #ifdef CONFIG_SYSVIPC 1150 struct sysv_sem sysvsem; 1151 struct sysv_shm sysvshm; 1152 #endif 1153 #ifdef CONFIG_DETECT_HUNG_TASK 1154 unsigned long last_switch_count; 1155 unsigned long last_switch_time; 1156 #endif 1157 /* Filesystem information: */ 1158 struct fs_struct *fs; 1159 1160 /* Open file information: */ 1161 struct files_struct *files; 1162 1163 #ifdef CONFIG_IO_URING 1164 struct io_uring_task *io_uring; 1165 #endif 1166 1167 /* Namespaces: */ 1168 struct nsproxy *nsproxy; 1169 1170 /* Signal handlers: */ 1171 struct signal_struct *signal; 1172 struct sighand_struct __rcu *sighand; 1173 sigset_t blocked; 1174 sigset_t real_blocked; 1175 /* Restored if set_restore_sigmask() was used: */ 1176 sigset_t saved_sigmask; 1177 struct sigpending pending; 1178 unsigned long sas_ss_sp; 1179 size_t sas_ss_size; 1180 unsigned int sas_ss_flags; 1181 1182 struct callback_head *task_works; 1183 1184 #ifdef CONFIG_AUDIT 1185 #ifdef CONFIG_AUDITSYSCALL 1186 struct audit_context *audit_context; 1187 #endif 1188 kuid_t loginuid; 1189 unsigned int sessionid; 1190 #endif 1191 struct seccomp seccomp; 1192 struct syscall_user_dispatch syscall_dispatch; 1193 1194 /* Thread group tracking: */ 1195 u64 parent_exec_id; 1196 u64 self_exec_id; 1197 1198 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1199 spinlock_t alloc_lock; 1200 1201 /* Protection of the PI data structures: */ 1202 raw_spinlock_t pi_lock; 1203 1204 struct wake_q_node wake_q; 1205 1206 #ifdef CONFIG_RT_MUTEXES 1207 /* PI waiters blocked on a rt_mutex held by this task: */ 1208 struct rb_root_cached pi_waiters; 1209 /* Updated under owner's pi_lock and rq lock */ 1210 struct task_struct *pi_top_task; 1211 /* Deadlock detection and priority inheritance handling: */ 1212 struct rt_mutex_waiter *pi_blocked_on; 1213 #endif 1214 1215 #ifdef CONFIG_DEBUG_MUTEXES 1216 /* Mutex deadlock detection: */ 1217 struct mutex_waiter *blocked_on; 1218 #endif 1219 1220 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1221 int non_block_count; 1222 #endif 1223 1224 #ifdef CONFIG_TRACE_IRQFLAGS 1225 struct irqtrace_events irqtrace; 1226 unsigned int hardirq_threaded; 1227 u64 hardirq_chain_key; 1228 int softirqs_enabled; 1229 int softirq_context; 1230 int irq_config; 1231 #endif 1232 #ifdef CONFIG_PREEMPT_RT 1233 int softirq_disable_cnt; 1234 #endif 1235 1236 #ifdef CONFIG_LOCKDEP 1237 # define MAX_LOCK_DEPTH 48UL 1238 u64 curr_chain_key; 1239 int lockdep_depth; 1240 unsigned int lockdep_recursion; 1241 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1242 #endif 1243 1244 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1245 unsigned int in_ubsan; 1246 #endif 1247 1248 /* Journalling filesystem info: */ 1249 void *journal_info; 1250 1251 /* Stacked block device info: */ 1252 struct bio_list *bio_list; 1253 1254 /* Stack plugging: */ 1255 struct blk_plug *plug; 1256 1257 /* VM state: */ 1258 struct reclaim_state *reclaim_state; 1259 1260 struct io_context *io_context; 1261 1262 #ifdef CONFIG_COMPACTION 1263 struct capture_control *capture_control; 1264 #endif 1265 /* Ptrace state: */ 1266 unsigned long ptrace_message; 1267 kernel_siginfo_t *last_siginfo; 1268 1269 struct task_io_accounting ioac; 1270 #ifdef CONFIG_PSI 1271 /* Pressure stall state */ 1272 unsigned int psi_flags; 1273 #endif 1274 #ifdef CONFIG_TASK_XACCT 1275 /* Accumulated RSS usage: */ 1276 u64 acct_rss_mem1; 1277 /* Accumulated virtual memory usage: */ 1278 u64 acct_vm_mem1; 1279 /* stime + utime since last update: */ 1280 u64 acct_timexpd; 1281 #endif 1282 #ifdef CONFIG_CPUSETS 1283 /* Protected by ->alloc_lock: */ 1284 nodemask_t mems_allowed; 1285 /* Sequence number to catch updates: */ 1286 seqcount_spinlock_t mems_allowed_seq; 1287 int cpuset_mem_spread_rotor; 1288 #endif 1289 #ifdef CONFIG_CGROUPS 1290 /* Control Group info protected by css_set_lock: */ 1291 struct css_set __rcu *cgroups; 1292 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1293 struct list_head cg_list; 1294 #endif 1295 #ifdef CONFIG_X86_CPU_RESCTRL 1296 u32 closid; 1297 u32 rmid; 1298 #endif 1299 #ifdef CONFIG_FUTEX 1300 struct robust_list_head __user *robust_list; 1301 #ifdef CONFIG_COMPAT 1302 struct compat_robust_list_head __user *compat_robust_list; 1303 #endif 1304 struct list_head pi_state_list; 1305 struct futex_pi_state *pi_state_cache; 1306 struct mutex futex_exit_mutex; 1307 unsigned int futex_state; 1308 #endif 1309 #ifdef CONFIG_PERF_EVENTS 1310 u8 perf_recursion[PERF_NR_CONTEXTS]; 1311 struct perf_event_context *perf_event_ctxp; 1312 struct mutex perf_event_mutex; 1313 struct list_head perf_event_list; 1314 #endif 1315 #ifdef CONFIG_DEBUG_PREEMPT 1316 unsigned long preempt_disable_ip; 1317 #endif 1318 #ifdef CONFIG_NUMA 1319 /* Protected by alloc_lock: */ 1320 struct mempolicy *mempolicy; 1321 short il_prev; 1322 u8 il_weight; 1323 short pref_node_fork; 1324 #endif 1325 #ifdef CONFIG_NUMA_BALANCING 1326 int numa_scan_seq; 1327 unsigned int numa_scan_period; 1328 unsigned int numa_scan_period_max; 1329 int numa_preferred_nid; 1330 unsigned long numa_migrate_retry; 1331 /* Migration stamp: */ 1332 u64 node_stamp; 1333 u64 last_task_numa_placement; 1334 u64 last_sum_exec_runtime; 1335 struct callback_head numa_work; 1336 1337 /* 1338 * This pointer is only modified for current in syscall and 1339 * pagefault context (and for tasks being destroyed), so it can be read 1340 * from any of the following contexts: 1341 * - RCU read-side critical section 1342 * - current->numa_group from everywhere 1343 * - task's runqueue locked, task not running 1344 */ 1345 struct numa_group __rcu *numa_group; 1346 1347 /* 1348 * numa_faults is an array split into four regions: 1349 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1350 * in this precise order. 1351 * 1352 * faults_memory: Exponential decaying average of faults on a per-node 1353 * basis. Scheduling placement decisions are made based on these 1354 * counts. The values remain static for the duration of a PTE scan. 1355 * faults_cpu: Track the nodes the process was running on when a NUMA 1356 * hinting fault was incurred. 1357 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1358 * during the current scan window. When the scan completes, the counts 1359 * in faults_memory and faults_cpu decay and these values are copied. 1360 */ 1361 unsigned long *numa_faults; 1362 unsigned long total_numa_faults; 1363 1364 /* 1365 * numa_faults_locality tracks if faults recorded during the last 1366 * scan window were remote/local or failed to migrate. The task scan 1367 * period is adapted based on the locality of the faults with different 1368 * weights depending on whether they were shared or private faults 1369 */ 1370 unsigned long numa_faults_locality[3]; 1371 1372 unsigned long numa_pages_migrated; 1373 #endif /* CONFIG_NUMA_BALANCING */ 1374 1375 #ifdef CONFIG_RSEQ 1376 struct rseq __user *rseq; 1377 u32 rseq_len; 1378 u32 rseq_sig; 1379 /* 1380 * RmW on rseq_event_mask must be performed atomically 1381 * with respect to preemption. 1382 */ 1383 unsigned long rseq_event_mask; 1384 # ifdef CONFIG_DEBUG_RSEQ 1385 /* 1386 * This is a place holder to save a copy of the rseq fields for 1387 * validation of read-only fields. The struct rseq has a 1388 * variable-length array at the end, so it cannot be used 1389 * directly. Reserve a size large enough for the known fields. 1390 */ 1391 char rseq_fields[sizeof(struct rseq)]; 1392 # endif 1393 #endif 1394 1395 #ifdef CONFIG_SCHED_MM_CID 1396 int mm_cid; /* Current cid in mm */ 1397 int last_mm_cid; /* Most recent cid in mm */ 1398 int migrate_from_cpu; 1399 int mm_cid_active; /* Whether cid bitmap is active */ 1400 struct callback_head cid_work; 1401 #endif 1402 1403 struct tlbflush_unmap_batch tlb_ubc; 1404 1405 /* Cache last used pipe for splice(): */ 1406 struct pipe_inode_info *splice_pipe; 1407 1408 struct page_frag task_frag; 1409 1410 #ifdef CONFIG_TASK_DELAY_ACCT 1411 struct task_delay_info *delays; 1412 #endif 1413 1414 #ifdef CONFIG_FAULT_INJECTION 1415 int make_it_fail; 1416 unsigned int fail_nth; 1417 #endif 1418 /* 1419 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1420 * balance_dirty_pages() for a dirty throttling pause: 1421 */ 1422 int nr_dirtied; 1423 int nr_dirtied_pause; 1424 /* Start of a write-and-pause period: */ 1425 unsigned long dirty_paused_when; 1426 1427 #ifdef CONFIG_LATENCYTOP 1428 int latency_record_count; 1429 struct latency_record latency_record[LT_SAVECOUNT]; 1430 #endif 1431 /* 1432 * Time slack values; these are used to round up poll() and 1433 * select() etc timeout values. These are in nanoseconds. 1434 */ 1435 u64 timer_slack_ns; 1436 u64 default_timer_slack_ns; 1437 1438 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1439 unsigned int kasan_depth; 1440 #endif 1441 1442 #ifdef CONFIG_KCSAN 1443 struct kcsan_ctx kcsan_ctx; 1444 #ifdef CONFIG_TRACE_IRQFLAGS 1445 struct irqtrace_events kcsan_save_irqtrace; 1446 #endif 1447 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1448 int kcsan_stack_depth; 1449 #endif 1450 #endif 1451 1452 #ifdef CONFIG_KMSAN 1453 struct kmsan_ctx kmsan_ctx; 1454 #endif 1455 1456 #if IS_ENABLED(CONFIG_KUNIT) 1457 struct kunit *kunit_test; 1458 #endif 1459 1460 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1461 /* Index of current stored address in ret_stack: */ 1462 int curr_ret_stack; 1463 int curr_ret_depth; 1464 1465 /* Stack of return addresses for return function tracing: */ 1466 unsigned long *ret_stack; 1467 1468 /* Timestamp for last schedule: */ 1469 unsigned long long ftrace_timestamp; 1470 unsigned long long ftrace_sleeptime; 1471 1472 /* 1473 * Number of functions that haven't been traced 1474 * because of depth overrun: 1475 */ 1476 atomic_t trace_overrun; 1477 1478 /* Pause tracing: */ 1479 atomic_t tracing_graph_pause; 1480 #endif 1481 1482 #ifdef CONFIG_TRACING 1483 /* Bitmask and counter of trace recursion: */ 1484 unsigned long trace_recursion; 1485 #endif /* CONFIG_TRACING */ 1486 1487 #ifdef CONFIG_KCOV 1488 /* See kernel/kcov.c for more details. */ 1489 1490 /* Coverage collection mode enabled for this task (0 if disabled): */ 1491 unsigned int kcov_mode; 1492 1493 /* Size of the kcov_area: */ 1494 unsigned int kcov_size; 1495 1496 /* Buffer for coverage collection: */ 1497 void *kcov_area; 1498 1499 /* KCOV descriptor wired with this task or NULL: */ 1500 struct kcov *kcov; 1501 1502 /* KCOV common handle for remote coverage collection: */ 1503 u64 kcov_handle; 1504 1505 /* KCOV sequence number: */ 1506 int kcov_sequence; 1507 1508 /* Collect coverage from softirq context: */ 1509 unsigned int kcov_softirq; 1510 #endif 1511 1512 #ifdef CONFIG_MEMCG_V1 1513 struct mem_cgroup *memcg_in_oom; 1514 #endif 1515 1516 #ifdef CONFIG_MEMCG 1517 /* Number of pages to reclaim on returning to userland: */ 1518 unsigned int memcg_nr_pages_over_high; 1519 1520 /* Used by memcontrol for targeted memcg charge: */ 1521 struct mem_cgroup *active_memcg; 1522 1523 /* Cache for current->cgroups->memcg->objcg lookups: */ 1524 struct obj_cgroup *objcg; 1525 #endif 1526 1527 #ifdef CONFIG_BLK_CGROUP 1528 struct gendisk *throttle_disk; 1529 #endif 1530 1531 #ifdef CONFIG_UPROBES 1532 struct uprobe_task *utask; 1533 #endif 1534 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1535 unsigned int sequential_io; 1536 unsigned int sequential_io_avg; 1537 #endif 1538 struct kmap_ctrl kmap_ctrl; 1539 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1540 unsigned long task_state_change; 1541 # ifdef CONFIG_PREEMPT_RT 1542 unsigned long saved_state_change; 1543 # endif 1544 #endif 1545 struct rcu_head rcu; 1546 refcount_t rcu_users; 1547 int pagefault_disabled; 1548 #ifdef CONFIG_MMU 1549 struct task_struct *oom_reaper_list; 1550 struct timer_list oom_reaper_timer; 1551 #endif 1552 #ifdef CONFIG_VMAP_STACK 1553 struct vm_struct *stack_vm_area; 1554 #endif 1555 #ifdef CONFIG_THREAD_INFO_IN_TASK 1556 /* A live task holds one reference: */ 1557 refcount_t stack_refcount; 1558 #endif 1559 #ifdef CONFIG_LIVEPATCH 1560 int patch_state; 1561 #endif 1562 #ifdef CONFIG_SECURITY 1563 /* Used by LSM modules for access restriction: */ 1564 void *security; 1565 #endif 1566 #ifdef CONFIG_BPF_SYSCALL 1567 /* Used by BPF task local storage */ 1568 struct bpf_local_storage __rcu *bpf_storage; 1569 /* Used for BPF run context */ 1570 struct bpf_run_ctx *bpf_ctx; 1571 #endif 1572 /* Used by BPF for per-TASK xdp storage */ 1573 struct bpf_net_context *bpf_net_context; 1574 1575 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1576 unsigned long lowest_stack; 1577 unsigned long prev_lowest_stack; 1578 #endif 1579 1580 #ifdef CONFIG_X86_MCE 1581 void __user *mce_vaddr; 1582 __u64 mce_kflags; 1583 u64 mce_addr; 1584 __u64 mce_ripv : 1, 1585 mce_whole_page : 1, 1586 __mce_reserved : 62; 1587 struct callback_head mce_kill_me; 1588 int mce_count; 1589 #endif 1590 1591 #ifdef CONFIG_KRETPROBES 1592 struct llist_head kretprobe_instances; 1593 #endif 1594 #ifdef CONFIG_RETHOOK 1595 struct llist_head rethooks; 1596 #endif 1597 1598 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1599 /* 1600 * If L1D flush is supported on mm context switch 1601 * then we use this callback head to queue kill work 1602 * to kill tasks that are not running on SMT disabled 1603 * cores 1604 */ 1605 struct callback_head l1d_flush_kill; 1606 #endif 1607 1608 #ifdef CONFIG_RV 1609 /* 1610 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1611 * If we find justification for more monitors, we can think 1612 * about adding more or developing a dynamic method. So far, 1613 * none of these are justified. 1614 */ 1615 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1616 #endif 1617 1618 #ifdef CONFIG_USER_EVENTS 1619 struct user_event_mm *user_event_mm; 1620 #endif 1621 1622 /* 1623 * New fields for task_struct should be added above here, so that 1624 * they are included in the randomized portion of task_struct. 1625 */ 1626 randomized_struct_fields_end 1627 1628 /* CPU-specific state of this task: */ 1629 struct thread_struct thread; 1630 1631 /* 1632 * WARNING: on x86, 'thread_struct' contains a variable-sized 1633 * structure. It *MUST* be at the end of 'task_struct'. 1634 * 1635 * Do not put anything below here! 1636 */ 1637 }; 1638 1639 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1640 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1641 1642 static inline unsigned int __task_state_index(unsigned int tsk_state, 1643 unsigned int tsk_exit_state) 1644 { 1645 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1646 1647 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1648 1649 if ((tsk_state & TASK_IDLE) == TASK_IDLE) 1650 state = TASK_REPORT_IDLE; 1651 1652 /* 1653 * We're lying here, but rather than expose a completely new task state 1654 * to userspace, we can make this appear as if the task has gone through 1655 * a regular rt_mutex_lock() call. 1656 * Report frozen tasks as uninterruptible. 1657 */ 1658 if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN)) 1659 state = TASK_UNINTERRUPTIBLE; 1660 1661 return fls(state); 1662 } 1663 1664 static inline unsigned int task_state_index(struct task_struct *tsk) 1665 { 1666 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1667 } 1668 1669 static inline char task_index_to_char(unsigned int state) 1670 { 1671 static const char state_char[] = "RSDTtXZPI"; 1672 1673 BUILD_BUG_ON(TASK_REPORT_MAX * 2 != 1 << (sizeof(state_char) - 1)); 1674 1675 return state_char[state]; 1676 } 1677 1678 static inline char task_state_to_char(struct task_struct *tsk) 1679 { 1680 return task_index_to_char(task_state_index(tsk)); 1681 } 1682 1683 extern struct pid *cad_pid; 1684 1685 /* 1686 * Per process flags 1687 */ 1688 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1689 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1690 #define PF_EXITING 0x00000004 /* Getting shut down */ 1691 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1692 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1693 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1694 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1695 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1696 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1697 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1698 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1699 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */ 1700 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1701 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1702 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1703 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1704 #define PF__HOLE__00010000 0x00010000 1705 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1706 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */ 1707 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */ 1708 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1709 * I am cleaning dirty pages from some other bdi. */ 1710 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1711 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1712 #define PF__HOLE__00800000 0x00800000 1713 #define PF__HOLE__01000000 0x01000000 1714 #define PF__HOLE__02000000 0x02000000 1715 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1716 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1717 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning. 1718 * See memalloc_pin_save() */ 1719 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */ 1720 #define PF__HOLE__40000000 0x40000000 1721 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1722 1723 /* 1724 * Only the _current_ task can read/write to tsk->flags, but other 1725 * tasks can access tsk->flags in readonly mode for example 1726 * with tsk_used_math (like during threaded core dumping). 1727 * There is however an exception to this rule during ptrace 1728 * or during fork: the ptracer task is allowed to write to the 1729 * child->flags of its traced child (same goes for fork, the parent 1730 * can write to the child->flags), because we're guaranteed the 1731 * child is not running and in turn not changing child->flags 1732 * at the same time the parent does it. 1733 */ 1734 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1735 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1736 #define clear_used_math() clear_stopped_child_used_math(current) 1737 #define set_used_math() set_stopped_child_used_math(current) 1738 1739 #define conditional_stopped_child_used_math(condition, child) \ 1740 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1741 1742 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1743 1744 #define copy_to_stopped_child_used_math(child) \ 1745 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1746 1747 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1748 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1749 #define used_math() tsk_used_math(current) 1750 1751 static __always_inline bool is_percpu_thread(void) 1752 { 1753 #ifdef CONFIG_SMP 1754 return (current->flags & PF_NO_SETAFFINITY) && 1755 (current->nr_cpus_allowed == 1); 1756 #else 1757 return true; 1758 #endif 1759 } 1760 1761 /* Per-process atomic flags. */ 1762 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1763 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1764 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1765 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1766 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1767 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1768 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1769 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1770 1771 #define TASK_PFA_TEST(name, func) \ 1772 static inline bool task_##func(struct task_struct *p) \ 1773 { return test_bit(PFA_##name, &p->atomic_flags); } 1774 1775 #define TASK_PFA_SET(name, func) \ 1776 static inline void task_set_##func(struct task_struct *p) \ 1777 { set_bit(PFA_##name, &p->atomic_flags); } 1778 1779 #define TASK_PFA_CLEAR(name, func) \ 1780 static inline void task_clear_##func(struct task_struct *p) \ 1781 { clear_bit(PFA_##name, &p->atomic_flags); } 1782 1783 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1784 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1785 1786 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1787 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1788 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1789 1790 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1791 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1792 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1793 1794 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1795 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1796 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1797 1798 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1799 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1800 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1801 1802 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1803 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1804 1805 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1806 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1807 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1808 1809 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1810 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1811 1812 static inline void 1813 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1814 { 1815 current->flags &= ~flags; 1816 current->flags |= orig_flags & flags; 1817 } 1818 1819 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1820 extern int task_can_attach(struct task_struct *p); 1821 extern int dl_bw_alloc(int cpu, u64 dl_bw); 1822 extern void dl_bw_free(int cpu, u64 dl_bw); 1823 #ifdef CONFIG_SMP 1824 1825 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */ 1826 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1827 1828 /** 1829 * set_cpus_allowed_ptr - set CPU affinity mask of a task 1830 * @p: the task 1831 * @new_mask: CPU affinity mask 1832 * 1833 * Return: zero if successful, or a negative error code 1834 */ 1835 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1836 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1837 extern void release_user_cpus_ptr(struct task_struct *p); 1838 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1839 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1840 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1841 #else 1842 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1843 { 1844 } 1845 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1846 { 1847 /* Opencoded cpumask_test_cpu(0, new_mask) to avoid dependency on cpumask.h */ 1848 if ((*cpumask_bits(new_mask) & 1) == 0) 1849 return -EINVAL; 1850 return 0; 1851 } 1852 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1853 { 1854 if (src->user_cpus_ptr) 1855 return -EINVAL; 1856 return 0; 1857 } 1858 static inline void release_user_cpus_ptr(struct task_struct *p) 1859 { 1860 WARN_ON(p->user_cpus_ptr); 1861 } 1862 1863 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1864 { 1865 return 0; 1866 } 1867 #endif 1868 1869 extern int yield_to(struct task_struct *p, bool preempt); 1870 extern void set_user_nice(struct task_struct *p, long nice); 1871 extern int task_prio(const struct task_struct *p); 1872 1873 /** 1874 * task_nice - return the nice value of a given task. 1875 * @p: the task in question. 1876 * 1877 * Return: The nice value [ -20 ... 0 ... 19 ]. 1878 */ 1879 static inline int task_nice(const struct task_struct *p) 1880 { 1881 return PRIO_TO_NICE((p)->static_prio); 1882 } 1883 1884 extern int can_nice(const struct task_struct *p, const int nice); 1885 extern int task_curr(const struct task_struct *p); 1886 extern int idle_cpu(int cpu); 1887 extern int available_idle_cpu(int cpu); 1888 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1889 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1890 extern void sched_set_fifo(struct task_struct *p); 1891 extern void sched_set_fifo_low(struct task_struct *p); 1892 extern void sched_set_normal(struct task_struct *p, int nice); 1893 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1894 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1895 extern struct task_struct *idle_task(int cpu); 1896 1897 /** 1898 * is_idle_task - is the specified task an idle task? 1899 * @p: the task in question. 1900 * 1901 * Return: 1 if @p is an idle task. 0 otherwise. 1902 */ 1903 static __always_inline bool is_idle_task(const struct task_struct *p) 1904 { 1905 return !!(p->flags & PF_IDLE); 1906 } 1907 1908 extern struct task_struct *curr_task(int cpu); 1909 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1910 1911 void yield(void); 1912 1913 union thread_union { 1914 struct task_struct task; 1915 #ifndef CONFIG_THREAD_INFO_IN_TASK 1916 struct thread_info thread_info; 1917 #endif 1918 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1919 }; 1920 1921 #ifndef CONFIG_THREAD_INFO_IN_TASK 1922 extern struct thread_info init_thread_info; 1923 #endif 1924 1925 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1926 1927 #ifdef CONFIG_THREAD_INFO_IN_TASK 1928 # define task_thread_info(task) (&(task)->thread_info) 1929 #else 1930 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1931 #endif 1932 1933 /* 1934 * find a task by one of its numerical ids 1935 * 1936 * find_task_by_pid_ns(): 1937 * finds a task by its pid in the specified namespace 1938 * find_task_by_vpid(): 1939 * finds a task by its virtual pid 1940 * 1941 * see also find_vpid() etc in include/linux/pid.h 1942 */ 1943 1944 extern struct task_struct *find_task_by_vpid(pid_t nr); 1945 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1946 1947 /* 1948 * find a task by its virtual pid and get the task struct 1949 */ 1950 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1951 1952 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1953 extern int wake_up_process(struct task_struct *tsk); 1954 extern void wake_up_new_task(struct task_struct *tsk); 1955 1956 #ifdef CONFIG_SMP 1957 extern void kick_process(struct task_struct *tsk); 1958 #else 1959 static inline void kick_process(struct task_struct *tsk) { } 1960 #endif 1961 1962 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1963 #define set_task_comm(tsk, from) ({ \ 1964 BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \ 1965 __set_task_comm(tsk, from, false); \ 1966 }) 1967 1968 /* 1969 * - Why not use task_lock()? 1970 * User space can randomly change their names anyway, so locking for readers 1971 * doesn't make sense. For writers, locking is probably necessary, as a race 1972 * condition could lead to long-term mixed results. 1973 * The strscpy_pad() in __set_task_comm() can ensure that the task comm is 1974 * always NUL-terminated and zero-padded. Therefore the race condition between 1975 * reader and writer is not an issue. 1976 * 1977 * - BUILD_BUG_ON() can help prevent the buf from being truncated. 1978 * Since the callers don't perform any return value checks, this safeguard is 1979 * necessary. 1980 */ 1981 #define get_task_comm(buf, tsk) ({ \ 1982 BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \ 1983 strscpy_pad(buf, (tsk)->comm); \ 1984 buf; \ 1985 }) 1986 1987 #ifdef CONFIG_SMP 1988 static __always_inline void scheduler_ipi(void) 1989 { 1990 /* 1991 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1992 * TIF_NEED_RESCHED remotely (for the first time) will also send 1993 * this IPI. 1994 */ 1995 preempt_fold_need_resched(); 1996 } 1997 #else 1998 static inline void scheduler_ipi(void) { } 1999 #endif 2000 2001 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 2002 2003 /* 2004 * Set thread flags in other task's structures. 2005 * See asm/thread_info.h for TIF_xxxx flags available: 2006 */ 2007 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2008 { 2009 set_ti_thread_flag(task_thread_info(tsk), flag); 2010 } 2011 2012 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2013 { 2014 clear_ti_thread_flag(task_thread_info(tsk), flag); 2015 } 2016 2017 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2018 bool value) 2019 { 2020 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2021 } 2022 2023 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2024 { 2025 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2026 } 2027 2028 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2029 { 2030 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2031 } 2032 2033 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2034 { 2035 return test_ti_thread_flag(task_thread_info(tsk), flag); 2036 } 2037 2038 static inline void set_tsk_need_resched(struct task_struct *tsk) 2039 { 2040 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2041 } 2042 2043 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2044 { 2045 atomic_long_andnot(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY, 2046 (atomic_long_t *)&task_thread_info(tsk)->flags); 2047 } 2048 2049 static inline int test_tsk_need_resched(struct task_struct *tsk) 2050 { 2051 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2052 } 2053 2054 /* 2055 * cond_resched() and cond_resched_lock(): latency reduction via 2056 * explicit rescheduling in places that are safe. The return 2057 * value indicates whether a reschedule was done in fact. 2058 * cond_resched_lock() will drop the spinlock before scheduling, 2059 */ 2060 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2061 extern int __cond_resched(void); 2062 2063 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2064 2065 void sched_dynamic_klp_enable(void); 2066 void sched_dynamic_klp_disable(void); 2067 2068 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2069 2070 static __always_inline int _cond_resched(void) 2071 { 2072 return static_call_mod(cond_resched)(); 2073 } 2074 2075 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2076 2077 extern int dynamic_cond_resched(void); 2078 2079 static __always_inline int _cond_resched(void) 2080 { 2081 return dynamic_cond_resched(); 2082 } 2083 2084 #else /* !CONFIG_PREEMPTION */ 2085 2086 static inline int _cond_resched(void) 2087 { 2088 klp_sched_try_switch(); 2089 return __cond_resched(); 2090 } 2091 2092 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2093 2094 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2095 2096 static inline int _cond_resched(void) 2097 { 2098 klp_sched_try_switch(); 2099 return 0; 2100 } 2101 2102 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2103 2104 #define cond_resched() ({ \ 2105 __might_resched(__FILE__, __LINE__, 0); \ 2106 _cond_resched(); \ 2107 }) 2108 2109 extern int __cond_resched_lock(spinlock_t *lock); 2110 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2111 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2112 2113 #define MIGHT_RESCHED_RCU_SHIFT 8 2114 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2115 2116 #ifndef CONFIG_PREEMPT_RT 2117 /* 2118 * Non RT kernels have an elevated preempt count due to the held lock, 2119 * but are not allowed to be inside a RCU read side critical section 2120 */ 2121 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2122 #else 2123 /* 2124 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2125 * cond_resched*lock() has to take that into account because it checks for 2126 * preempt_count() and rcu_preempt_depth(). 2127 */ 2128 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2129 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2130 #endif 2131 2132 #define cond_resched_lock(lock) ({ \ 2133 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2134 __cond_resched_lock(lock); \ 2135 }) 2136 2137 #define cond_resched_rwlock_read(lock) ({ \ 2138 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2139 __cond_resched_rwlock_read(lock); \ 2140 }) 2141 2142 #define cond_resched_rwlock_write(lock) ({ \ 2143 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2144 __cond_resched_rwlock_write(lock); \ 2145 }) 2146 2147 static __always_inline bool need_resched(void) 2148 { 2149 return unlikely(tif_need_resched()); 2150 } 2151 2152 /* 2153 * Wrappers for p->thread_info->cpu access. No-op on UP. 2154 */ 2155 #ifdef CONFIG_SMP 2156 2157 static inline unsigned int task_cpu(const struct task_struct *p) 2158 { 2159 return READ_ONCE(task_thread_info(p)->cpu); 2160 } 2161 2162 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2163 2164 #else 2165 2166 static inline unsigned int task_cpu(const struct task_struct *p) 2167 { 2168 return 0; 2169 } 2170 2171 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2172 { 2173 } 2174 2175 #endif /* CONFIG_SMP */ 2176 2177 static inline bool task_is_runnable(struct task_struct *p) 2178 { 2179 return p->on_rq && !p->se.sched_delayed; 2180 } 2181 2182 extern bool sched_task_on_rq(struct task_struct *p); 2183 extern unsigned long get_wchan(struct task_struct *p); 2184 extern struct task_struct *cpu_curr_snapshot(int cpu); 2185 2186 #include <linux/spinlock.h> 2187 2188 /* 2189 * In order to reduce various lock holder preemption latencies provide an 2190 * interface to see if a vCPU is currently running or not. 2191 * 2192 * This allows us to terminate optimistic spin loops and block, analogous to 2193 * the native optimistic spin heuristic of testing if the lock owner task is 2194 * running or not. 2195 */ 2196 #ifndef vcpu_is_preempted 2197 static inline bool vcpu_is_preempted(int cpu) 2198 { 2199 return false; 2200 } 2201 #endif 2202 2203 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2204 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2205 2206 #ifndef TASK_SIZE_OF 2207 #define TASK_SIZE_OF(tsk) TASK_SIZE 2208 #endif 2209 2210 #ifdef CONFIG_SMP 2211 static inline bool owner_on_cpu(struct task_struct *owner) 2212 { 2213 /* 2214 * As lock holder preemption issue, we both skip spinning if 2215 * task is not on cpu or its cpu is preempted 2216 */ 2217 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2218 } 2219 2220 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2221 unsigned long sched_cpu_util(int cpu); 2222 #endif /* CONFIG_SMP */ 2223 2224 #ifdef CONFIG_SCHED_CORE 2225 extern void sched_core_free(struct task_struct *tsk); 2226 extern void sched_core_fork(struct task_struct *p); 2227 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2228 unsigned long uaddr); 2229 extern int sched_core_idle_cpu(int cpu); 2230 #else 2231 static inline void sched_core_free(struct task_struct *tsk) { } 2232 static inline void sched_core_fork(struct task_struct *p) { } 2233 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); } 2234 #endif 2235 2236 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2237 2238 #ifdef CONFIG_MEM_ALLOC_PROFILING 2239 static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag) 2240 { 2241 swap(current->alloc_tag, tag); 2242 return tag; 2243 } 2244 2245 static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old) 2246 { 2247 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 2248 WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n"); 2249 #endif 2250 current->alloc_tag = old; 2251 } 2252 #else 2253 #define alloc_tag_save(_tag) NULL 2254 #define alloc_tag_restore(_tag, _old) do {} while (0) 2255 #endif 2256 2257 #endif 2258