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 extern void sched_domains_mutex_lock(void); 386 extern void sched_domains_mutex_unlock(void); 387 #else 388 static inline void sched_domains_mutex_lock(void) { } 389 static inline void sched_domains_mutex_unlock(void) { } 390 #endif 391 392 struct sched_param { 393 int sched_priority; 394 }; 395 396 struct sched_info { 397 #ifdef CONFIG_SCHED_INFO 398 /* Cumulative counters: */ 399 400 /* # of times we have run on this CPU: */ 401 unsigned long pcount; 402 403 /* Time spent waiting on a runqueue: */ 404 unsigned long long run_delay; 405 406 /* Max time spent waiting on a runqueue: */ 407 unsigned long long max_run_delay; 408 409 /* Min time spent waiting on a runqueue: */ 410 unsigned long long min_run_delay; 411 412 /* Timestamps: */ 413 414 /* When did we last run on a CPU? */ 415 unsigned long long last_arrival; 416 417 /* When were we last queued to run? */ 418 unsigned long long last_queued; 419 420 #endif /* CONFIG_SCHED_INFO */ 421 }; 422 423 /* 424 * Integer metrics need fixed point arithmetic, e.g., sched/fair 425 * has a few: load, load_avg, util_avg, freq, and capacity. 426 * 427 * We define a basic fixed point arithmetic range, and then formalize 428 * all these metrics based on that basic range. 429 */ 430 # define SCHED_FIXEDPOINT_SHIFT 10 431 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 432 433 /* Increase resolution of cpu_capacity calculations */ 434 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 435 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 436 437 struct load_weight { 438 unsigned long weight; 439 u32 inv_weight; 440 }; 441 442 /* 443 * The load/runnable/util_avg accumulates an infinite geometric series 444 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 445 * 446 * [load_avg definition] 447 * 448 * load_avg = runnable% * scale_load_down(load) 449 * 450 * [runnable_avg definition] 451 * 452 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 453 * 454 * [util_avg definition] 455 * 456 * util_avg = running% * SCHED_CAPACITY_SCALE 457 * 458 * where runnable% is the time ratio that a sched_entity is runnable and 459 * running% the time ratio that a sched_entity is running. 460 * 461 * For cfs_rq, they are the aggregated values of all runnable and blocked 462 * sched_entities. 463 * 464 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 465 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 466 * for computing those signals (see update_rq_clock_pelt()) 467 * 468 * N.B., the above ratios (runnable% and running%) themselves are in the 469 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 470 * to as large a range as necessary. This is for example reflected by 471 * util_avg's SCHED_CAPACITY_SCALE. 472 * 473 * [Overflow issue] 474 * 475 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 476 * with the highest load (=88761), always runnable on a single cfs_rq, 477 * and should not overflow as the number already hits PID_MAX_LIMIT. 478 * 479 * For all other cases (including 32-bit kernels), struct load_weight's 480 * weight will overflow first before we do, because: 481 * 482 * Max(load_avg) <= Max(load.weight) 483 * 484 * Then it is the load_weight's responsibility to consider overflow 485 * issues. 486 */ 487 struct sched_avg { 488 u64 last_update_time; 489 u64 load_sum; 490 u64 runnable_sum; 491 u32 util_sum; 492 u32 period_contrib; 493 unsigned long load_avg; 494 unsigned long runnable_avg; 495 unsigned long util_avg; 496 unsigned int util_est; 497 } ____cacheline_aligned; 498 499 /* 500 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 501 * updates. When a task is dequeued, its util_est should not be updated if its 502 * util_avg has not been updated in the meantime. 503 * This information is mapped into the MSB bit of util_est at dequeue time. 504 * Since max value of util_est for a task is 1024 (PELT util_avg for a task) 505 * it is safe to use MSB. 506 */ 507 #define UTIL_EST_WEIGHT_SHIFT 2 508 #define UTIL_AVG_UNCHANGED 0x80000000 509 510 struct sched_statistics { 511 #ifdef CONFIG_SCHEDSTATS 512 u64 wait_start; 513 u64 wait_max; 514 u64 wait_count; 515 u64 wait_sum; 516 u64 iowait_count; 517 u64 iowait_sum; 518 519 u64 sleep_start; 520 u64 sleep_max; 521 s64 sum_sleep_runtime; 522 523 u64 block_start; 524 u64 block_max; 525 s64 sum_block_runtime; 526 527 s64 exec_max; 528 u64 slice_max; 529 530 u64 nr_migrations_cold; 531 u64 nr_failed_migrations_affine; 532 u64 nr_failed_migrations_running; 533 u64 nr_failed_migrations_hot; 534 u64 nr_forced_migrations; 535 536 u64 nr_wakeups; 537 u64 nr_wakeups_sync; 538 u64 nr_wakeups_migrate; 539 u64 nr_wakeups_local; 540 u64 nr_wakeups_remote; 541 u64 nr_wakeups_affine; 542 u64 nr_wakeups_affine_attempts; 543 u64 nr_wakeups_passive; 544 u64 nr_wakeups_idle; 545 546 #ifdef CONFIG_SCHED_CORE 547 u64 core_forceidle_sum; 548 #endif 549 #endif /* CONFIG_SCHEDSTATS */ 550 } ____cacheline_aligned; 551 552 struct sched_entity { 553 /* For load-balancing: */ 554 struct load_weight load; 555 struct rb_node run_node; 556 u64 deadline; 557 u64 min_vruntime; 558 u64 min_slice; 559 560 struct list_head group_node; 561 unsigned char on_rq; 562 unsigned char sched_delayed; 563 unsigned char rel_deadline; 564 unsigned char custom_slice; 565 /* hole */ 566 567 u64 exec_start; 568 u64 sum_exec_runtime; 569 u64 prev_sum_exec_runtime; 570 u64 vruntime; 571 s64 vlag; 572 u64 slice; 573 574 u64 nr_migrations; 575 576 #ifdef CONFIG_FAIR_GROUP_SCHED 577 int depth; 578 struct sched_entity *parent; 579 /* rq on which this entity is (to be) queued: */ 580 struct cfs_rq *cfs_rq; 581 /* rq "owned" by this entity/group: */ 582 struct cfs_rq *my_q; 583 /* cached value of my_q->h_nr_running */ 584 unsigned long runnable_weight; 585 #endif 586 587 #ifdef CONFIG_SMP 588 /* 589 * Per entity load average tracking. 590 * 591 * Put into separate cache line so it does not 592 * collide with read-mostly values above. 593 */ 594 struct sched_avg avg; 595 #endif 596 }; 597 598 struct sched_rt_entity { 599 struct list_head run_list; 600 unsigned long timeout; 601 unsigned long watchdog_stamp; 602 unsigned int time_slice; 603 unsigned short on_rq; 604 unsigned short on_list; 605 606 struct sched_rt_entity *back; 607 #ifdef CONFIG_RT_GROUP_SCHED 608 struct sched_rt_entity *parent; 609 /* rq on which this entity is (to be) queued: */ 610 struct rt_rq *rt_rq; 611 /* rq "owned" by this entity/group: */ 612 struct rt_rq *my_q; 613 #endif 614 } __randomize_layout; 615 616 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *); 617 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *); 618 619 struct sched_dl_entity { 620 struct rb_node rb_node; 621 622 /* 623 * Original scheduling parameters. Copied here from sched_attr 624 * during sched_setattr(), they will remain the same until 625 * the next sched_setattr(). 626 */ 627 u64 dl_runtime; /* Maximum runtime for each instance */ 628 u64 dl_deadline; /* Relative deadline of each instance */ 629 u64 dl_period; /* Separation of two instances (period) */ 630 u64 dl_bw; /* dl_runtime / dl_period */ 631 u64 dl_density; /* dl_runtime / dl_deadline */ 632 633 /* 634 * Actual scheduling parameters. Initialized with the values above, 635 * they are continuously updated during task execution. Note that 636 * the remaining runtime could be < 0 in case we are in overrun. 637 */ 638 s64 runtime; /* Remaining runtime for this instance */ 639 u64 deadline; /* Absolute deadline for this instance */ 640 unsigned int flags; /* Specifying the scheduler behaviour */ 641 642 /* 643 * Some bool flags: 644 * 645 * @dl_throttled tells if we exhausted the runtime. If so, the 646 * task has to wait for a replenishment to be performed at the 647 * next firing of dl_timer. 648 * 649 * @dl_yielded tells if task gave up the CPU before consuming 650 * all its available runtime during the last job. 651 * 652 * @dl_non_contending tells if the task is inactive while still 653 * contributing to the active utilization. In other words, it 654 * indicates if the inactive timer has been armed and its handler 655 * has not been executed yet. This flag is useful to avoid race 656 * conditions between the inactive timer handler and the wakeup 657 * code. 658 * 659 * @dl_overrun tells if the task asked to be informed about runtime 660 * overruns. 661 * 662 * @dl_server tells if this is a server entity. 663 * 664 * @dl_defer tells if this is a deferred or regular server. For 665 * now only defer server exists. 666 * 667 * @dl_defer_armed tells if the deferrable server is waiting 668 * for the replenishment timer to activate it. 669 * 670 * @dl_server_active tells if the dlserver is active(started). 671 * dlserver is started on first cfs enqueue on an idle runqueue 672 * and is stopped when a dequeue results in 0 cfs tasks on the 673 * runqueue. In other words, dlserver is active only when cpu's 674 * runqueue has atleast one cfs task. 675 * 676 * @dl_defer_running tells if the deferrable server is actually 677 * running, skipping the defer phase. 678 */ 679 unsigned int dl_throttled : 1; 680 unsigned int dl_yielded : 1; 681 unsigned int dl_non_contending : 1; 682 unsigned int dl_overrun : 1; 683 unsigned int dl_server : 1; 684 unsigned int dl_server_active : 1; 685 unsigned int dl_defer : 1; 686 unsigned int dl_defer_armed : 1; 687 unsigned int dl_defer_running : 1; 688 689 /* 690 * Bandwidth enforcement timer. Each -deadline task has its 691 * own bandwidth to be enforced, thus we need one timer per task. 692 */ 693 struct hrtimer dl_timer; 694 695 /* 696 * Inactive timer, responsible for decreasing the active utilization 697 * at the "0-lag time". When a -deadline task blocks, it contributes 698 * to GRUB's active utilization until the "0-lag time", hence a 699 * timer is needed to decrease the active utilization at the correct 700 * time. 701 */ 702 struct hrtimer inactive_timer; 703 704 /* 705 * Bits for DL-server functionality. Also see the comment near 706 * dl_server_update(). 707 * 708 * @rq the runqueue this server is for 709 * 710 * @server_has_tasks() returns true if @server_pick return a 711 * runnable task. 712 */ 713 struct rq *rq; 714 dl_server_has_tasks_f server_has_tasks; 715 dl_server_pick_f server_pick_task; 716 717 #ifdef CONFIG_RT_MUTEXES 718 /* 719 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 720 * pi_se points to the donor, otherwise points to the dl_se it belongs 721 * to (the original one/itself). 722 */ 723 struct sched_dl_entity *pi_se; 724 #endif 725 }; 726 727 #ifdef CONFIG_UCLAMP_TASK 728 /* Number of utilization clamp buckets (shorter alias) */ 729 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 730 731 /* 732 * Utilization clamp for a scheduling entity 733 * @value: clamp value "assigned" to a se 734 * @bucket_id: bucket index corresponding to the "assigned" value 735 * @active: the se is currently refcounted in a rq's bucket 736 * @user_defined: the requested clamp value comes from user-space 737 * 738 * The bucket_id is the index of the clamp bucket matching the clamp value 739 * which is pre-computed and stored to avoid expensive integer divisions from 740 * the fast path. 741 * 742 * The active bit is set whenever a task has got an "effective" value assigned, 743 * which can be different from the clamp value "requested" from user-space. 744 * This allows to know a task is refcounted in the rq's bucket corresponding 745 * to the "effective" bucket_id. 746 * 747 * The user_defined bit is set whenever a task has got a task-specific clamp 748 * value requested from userspace, i.e. the system defaults apply to this task 749 * just as a restriction. This allows to relax default clamps when a less 750 * restrictive task-specific value has been requested, thus allowing to 751 * implement a "nice" semantic. For example, a task running with a 20% 752 * default boost can still drop its own boosting to 0%. 753 */ 754 struct uclamp_se { 755 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 756 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 757 unsigned int active : 1; 758 unsigned int user_defined : 1; 759 }; 760 #endif /* CONFIG_UCLAMP_TASK */ 761 762 union rcu_special { 763 struct { 764 u8 blocked; 765 u8 need_qs; 766 u8 exp_hint; /* Hint for performance. */ 767 u8 need_mb; /* Readers need smp_mb(). */ 768 } b; /* Bits. */ 769 u32 s; /* Set of bits. */ 770 }; 771 772 enum perf_event_task_context { 773 perf_invalid_context = -1, 774 perf_hw_context = 0, 775 perf_sw_context, 776 perf_nr_task_contexts, 777 }; 778 779 /* 780 * Number of contexts where an event can trigger: 781 * task, softirq, hardirq, nmi. 782 */ 783 #define PERF_NR_CONTEXTS 4 784 785 struct wake_q_node { 786 struct wake_q_node *next; 787 }; 788 789 struct kmap_ctrl { 790 #ifdef CONFIG_KMAP_LOCAL 791 int idx; 792 pte_t pteval[KM_MAX_IDX]; 793 #endif 794 }; 795 796 struct task_struct { 797 #ifdef CONFIG_THREAD_INFO_IN_TASK 798 /* 799 * For reasons of header soup (see current_thread_info()), this 800 * must be the first element of task_struct. 801 */ 802 struct thread_info thread_info; 803 #endif 804 unsigned int __state; 805 806 /* saved state for "spinlock sleepers" */ 807 unsigned int saved_state; 808 809 /* 810 * This begins the randomizable portion of task_struct. Only 811 * scheduling-critical items should be added above here. 812 */ 813 randomized_struct_fields_start 814 815 void *stack; 816 refcount_t usage; 817 /* Per task flags (PF_*), defined further below: */ 818 unsigned int flags; 819 unsigned int ptrace; 820 821 #ifdef CONFIG_MEM_ALLOC_PROFILING 822 struct alloc_tag *alloc_tag; 823 #endif 824 825 #ifdef CONFIG_SMP 826 int on_cpu; 827 struct __call_single_node wake_entry; 828 unsigned int wakee_flips; 829 unsigned long wakee_flip_decay_ts; 830 struct task_struct *last_wakee; 831 832 /* 833 * recent_used_cpu is initially set as the last CPU used by a task 834 * that wakes affine another task. Waker/wakee relationships can 835 * push tasks around a CPU where each wakeup moves to the next one. 836 * Tracking a recently used CPU allows a quick search for a recently 837 * used CPU that may be idle. 838 */ 839 int recent_used_cpu; 840 int wake_cpu; 841 #endif 842 int on_rq; 843 844 int prio; 845 int static_prio; 846 int normal_prio; 847 unsigned int rt_priority; 848 849 struct sched_entity se; 850 struct sched_rt_entity rt; 851 struct sched_dl_entity dl; 852 struct sched_dl_entity *dl_server; 853 #ifdef CONFIG_SCHED_CLASS_EXT 854 struct sched_ext_entity scx; 855 #endif 856 const struct sched_class *sched_class; 857 858 #ifdef CONFIG_SCHED_CORE 859 struct rb_node core_node; 860 unsigned long core_cookie; 861 unsigned int core_occupation; 862 #endif 863 864 #ifdef CONFIG_CGROUP_SCHED 865 struct task_group *sched_task_group; 866 #endif 867 868 869 #ifdef CONFIG_UCLAMP_TASK 870 /* 871 * Clamp values requested for a scheduling entity. 872 * Must be updated with task_rq_lock() held. 873 */ 874 struct uclamp_se uclamp_req[UCLAMP_CNT]; 875 /* 876 * Effective clamp values used for a scheduling entity. 877 * Must be updated with task_rq_lock() held. 878 */ 879 struct uclamp_se uclamp[UCLAMP_CNT]; 880 #endif 881 882 struct sched_statistics stats; 883 884 #ifdef CONFIG_PREEMPT_NOTIFIERS 885 /* List of struct preempt_notifier: */ 886 struct hlist_head preempt_notifiers; 887 #endif 888 889 #ifdef CONFIG_BLK_DEV_IO_TRACE 890 unsigned int btrace_seq; 891 #endif 892 893 unsigned int policy; 894 unsigned long max_allowed_capacity; 895 int nr_cpus_allowed; 896 const cpumask_t *cpus_ptr; 897 cpumask_t *user_cpus_ptr; 898 cpumask_t cpus_mask; 899 void *migration_pending; 900 #ifdef CONFIG_SMP 901 unsigned short migration_disabled; 902 #endif 903 unsigned short migration_flags; 904 905 #ifdef CONFIG_PREEMPT_RCU 906 int rcu_read_lock_nesting; 907 union rcu_special rcu_read_unlock_special; 908 struct list_head rcu_node_entry; 909 struct rcu_node *rcu_blocked_node; 910 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 911 912 #ifdef CONFIG_TASKS_RCU 913 unsigned long rcu_tasks_nvcsw; 914 u8 rcu_tasks_holdout; 915 u8 rcu_tasks_idx; 916 int rcu_tasks_idle_cpu; 917 struct list_head rcu_tasks_holdout_list; 918 int rcu_tasks_exit_cpu; 919 struct list_head rcu_tasks_exit_list; 920 #endif /* #ifdef CONFIG_TASKS_RCU */ 921 922 #ifdef CONFIG_TASKS_TRACE_RCU 923 int trc_reader_nesting; 924 int trc_ipi_to_cpu; 925 union rcu_special trc_reader_special; 926 struct list_head trc_holdout_list; 927 struct list_head trc_blkd_node; 928 int trc_blkd_cpu; 929 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 930 931 struct sched_info sched_info; 932 933 struct list_head tasks; 934 #ifdef CONFIG_SMP 935 struct plist_node pushable_tasks; 936 struct rb_node pushable_dl_tasks; 937 #endif 938 939 struct mm_struct *mm; 940 struct mm_struct *active_mm; 941 struct address_space *faults_disabled_mapping; 942 943 int exit_state; 944 int exit_code; 945 int exit_signal; 946 /* The signal sent when the parent dies: */ 947 int pdeath_signal; 948 /* JOBCTL_*, siglock protected: */ 949 unsigned long jobctl; 950 951 /* Used for emulating ABI behavior of previous Linux versions: */ 952 unsigned int personality; 953 954 /* Scheduler bits, serialized by scheduler locks: */ 955 unsigned sched_reset_on_fork:1; 956 unsigned sched_contributes_to_load:1; 957 unsigned sched_migrated:1; 958 unsigned sched_task_hot:1; 959 960 /* Force alignment to the next boundary: */ 961 unsigned :0; 962 963 /* Unserialized, strictly 'current' */ 964 965 /* 966 * This field must not be in the scheduler word above due to wakelist 967 * queueing no longer being serialized by p->on_cpu. However: 968 * 969 * p->XXX = X; ttwu() 970 * schedule() if (p->on_rq && ..) // false 971 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 972 * deactivate_task() ttwu_queue_wakelist()) 973 * p->on_rq = 0; p->sched_remote_wakeup = Y; 974 * 975 * guarantees all stores of 'current' are visible before 976 * ->sched_remote_wakeup gets used, so it can be in this word. 977 */ 978 unsigned sched_remote_wakeup:1; 979 #ifdef CONFIG_RT_MUTEXES 980 unsigned sched_rt_mutex:1; 981 #endif 982 983 /* Bit to tell TOMOYO we're in execve(): */ 984 unsigned in_execve:1; 985 unsigned in_iowait:1; 986 #ifndef TIF_RESTORE_SIGMASK 987 unsigned restore_sigmask:1; 988 #endif 989 #ifdef CONFIG_MEMCG_V1 990 unsigned in_user_fault:1; 991 #endif 992 #ifdef CONFIG_LRU_GEN 993 /* whether the LRU algorithm may apply to this access */ 994 unsigned in_lru_fault:1; 995 #endif 996 #ifdef CONFIG_COMPAT_BRK 997 unsigned brk_randomized:1; 998 #endif 999 #ifdef CONFIG_CGROUPS 1000 /* disallow userland-initiated cgroup migration */ 1001 unsigned no_cgroup_migration:1; 1002 /* task is frozen/stopped (used by the cgroup freezer) */ 1003 unsigned frozen:1; 1004 #endif 1005 #ifdef CONFIG_BLK_CGROUP 1006 unsigned use_memdelay:1; 1007 #endif 1008 #ifdef CONFIG_PSI 1009 /* Stalled due to lack of memory */ 1010 unsigned in_memstall:1; 1011 #endif 1012 #ifdef CONFIG_PAGE_OWNER 1013 /* Used by page_owner=on to detect recursion in page tracking. */ 1014 unsigned in_page_owner:1; 1015 #endif 1016 #ifdef CONFIG_EVENTFD 1017 /* Recursion prevention for eventfd_signal() */ 1018 unsigned in_eventfd:1; 1019 #endif 1020 #ifdef CONFIG_ARCH_HAS_CPU_PASID 1021 unsigned pasid_activated:1; 1022 #endif 1023 #ifdef CONFIG_X86_BUS_LOCK_DETECT 1024 unsigned reported_split_lock:1; 1025 #endif 1026 #ifdef CONFIG_TASK_DELAY_ACCT 1027 /* delay due to memory thrashing */ 1028 unsigned in_thrashing:1; 1029 #endif 1030 #ifdef CONFIG_PREEMPT_RT 1031 struct netdev_xmit net_xmit; 1032 #endif 1033 unsigned long atomic_flags; /* Flags requiring atomic access. */ 1034 1035 struct restart_block restart_block; 1036 1037 pid_t pid; 1038 pid_t tgid; 1039 1040 #ifdef CONFIG_STACKPROTECTOR 1041 /* Canary value for the -fstack-protector GCC feature: */ 1042 unsigned long stack_canary; 1043 #endif 1044 /* 1045 * Pointers to the (original) parent process, youngest child, younger sibling, 1046 * older sibling, respectively. (p->father can be replaced with 1047 * p->real_parent->pid) 1048 */ 1049 1050 /* Real parent process: */ 1051 struct task_struct __rcu *real_parent; 1052 1053 /* Recipient of SIGCHLD, wait4() reports: */ 1054 struct task_struct __rcu *parent; 1055 1056 /* 1057 * Children/sibling form the list of natural children: 1058 */ 1059 struct list_head children; 1060 struct list_head sibling; 1061 struct task_struct *group_leader; 1062 1063 /* 1064 * 'ptraced' is the list of tasks this task is using ptrace() on. 1065 * 1066 * This includes both natural children and PTRACE_ATTACH targets. 1067 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 1068 */ 1069 struct list_head ptraced; 1070 struct list_head ptrace_entry; 1071 1072 /* PID/PID hash table linkage. */ 1073 struct pid *thread_pid; 1074 struct hlist_node pid_links[PIDTYPE_MAX]; 1075 struct list_head thread_node; 1076 1077 struct completion *vfork_done; 1078 1079 /* CLONE_CHILD_SETTID: */ 1080 int __user *set_child_tid; 1081 1082 /* CLONE_CHILD_CLEARTID: */ 1083 int __user *clear_child_tid; 1084 1085 /* PF_KTHREAD | PF_IO_WORKER */ 1086 void *worker_private; 1087 1088 u64 utime; 1089 u64 stime; 1090 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1091 u64 utimescaled; 1092 u64 stimescaled; 1093 #endif 1094 u64 gtime; 1095 struct prev_cputime prev_cputime; 1096 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1097 struct vtime vtime; 1098 #endif 1099 1100 #ifdef CONFIG_NO_HZ_FULL 1101 atomic_t tick_dep_mask; 1102 #endif 1103 /* Context switch counts: */ 1104 unsigned long nvcsw; 1105 unsigned long nivcsw; 1106 1107 /* Monotonic time in nsecs: */ 1108 u64 start_time; 1109 1110 /* Boot based time in nsecs: */ 1111 u64 start_boottime; 1112 1113 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1114 unsigned long min_flt; 1115 unsigned long maj_flt; 1116 1117 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1118 struct posix_cputimers posix_cputimers; 1119 1120 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1121 struct posix_cputimers_work posix_cputimers_work; 1122 #endif 1123 1124 /* Process credentials: */ 1125 1126 /* Tracer's credentials at attach: */ 1127 const struct cred __rcu *ptracer_cred; 1128 1129 /* Objective and real subjective task credentials (COW): */ 1130 const struct cred __rcu *real_cred; 1131 1132 /* Effective (overridable) subjective task credentials (COW): */ 1133 const struct cred __rcu *cred; 1134 1135 #ifdef CONFIG_KEYS 1136 /* Cached requested key. */ 1137 struct key *cached_requested_key; 1138 #endif 1139 1140 /* 1141 * executable name, excluding path. 1142 * 1143 * - normally initialized begin_new_exec() 1144 * - set it with set_task_comm() 1145 * - strscpy_pad() to ensure it is always NUL-terminated and 1146 * zero-padded 1147 * - task_lock() to ensure the operation is atomic and the name is 1148 * fully updated. 1149 */ 1150 char comm[TASK_COMM_LEN]; 1151 1152 struct nameidata *nameidata; 1153 1154 #ifdef CONFIG_SYSVIPC 1155 struct sysv_sem sysvsem; 1156 struct sysv_shm sysvshm; 1157 #endif 1158 #ifdef CONFIG_DETECT_HUNG_TASK 1159 unsigned long last_switch_count; 1160 unsigned long last_switch_time; 1161 #endif 1162 /* Filesystem information: */ 1163 struct fs_struct *fs; 1164 1165 /* Open file information: */ 1166 struct files_struct *files; 1167 1168 #ifdef CONFIG_IO_URING 1169 struct io_uring_task *io_uring; 1170 #endif 1171 1172 /* Namespaces: */ 1173 struct nsproxy *nsproxy; 1174 1175 /* Signal handlers: */ 1176 struct signal_struct *signal; 1177 struct sighand_struct __rcu *sighand; 1178 sigset_t blocked; 1179 sigset_t real_blocked; 1180 /* Restored if set_restore_sigmask() was used: */ 1181 sigset_t saved_sigmask; 1182 struct sigpending pending; 1183 unsigned long sas_ss_sp; 1184 size_t sas_ss_size; 1185 unsigned int sas_ss_flags; 1186 1187 struct callback_head *task_works; 1188 1189 #ifdef CONFIG_AUDIT 1190 #ifdef CONFIG_AUDITSYSCALL 1191 struct audit_context *audit_context; 1192 #endif 1193 kuid_t loginuid; 1194 unsigned int sessionid; 1195 #endif 1196 struct seccomp seccomp; 1197 struct syscall_user_dispatch syscall_dispatch; 1198 1199 /* Thread group tracking: */ 1200 u64 parent_exec_id; 1201 u64 self_exec_id; 1202 1203 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1204 spinlock_t alloc_lock; 1205 1206 /* Protection of the PI data structures: */ 1207 raw_spinlock_t pi_lock; 1208 1209 struct wake_q_node wake_q; 1210 1211 #ifdef CONFIG_RT_MUTEXES 1212 /* PI waiters blocked on a rt_mutex held by this task: */ 1213 struct rb_root_cached pi_waiters; 1214 /* Updated under owner's pi_lock and rq lock */ 1215 struct task_struct *pi_top_task; 1216 /* Deadlock detection and priority inheritance handling: */ 1217 struct rt_mutex_waiter *pi_blocked_on; 1218 #endif 1219 1220 #ifdef CONFIG_DEBUG_MUTEXES 1221 /* Mutex deadlock detection: */ 1222 struct mutex_waiter *blocked_on; 1223 #endif 1224 1225 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1226 int non_block_count; 1227 #endif 1228 1229 #ifdef CONFIG_TRACE_IRQFLAGS 1230 struct irqtrace_events irqtrace; 1231 unsigned int hardirq_threaded; 1232 u64 hardirq_chain_key; 1233 int softirqs_enabled; 1234 int softirq_context; 1235 int irq_config; 1236 #endif 1237 #ifdef CONFIG_PREEMPT_RT 1238 int softirq_disable_cnt; 1239 #endif 1240 1241 #ifdef CONFIG_LOCKDEP 1242 # define MAX_LOCK_DEPTH 48UL 1243 u64 curr_chain_key; 1244 int lockdep_depth; 1245 unsigned int lockdep_recursion; 1246 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1247 #endif 1248 1249 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1250 unsigned int in_ubsan; 1251 #endif 1252 1253 /* Journalling filesystem info: */ 1254 void *journal_info; 1255 1256 /* Stacked block device info: */ 1257 struct bio_list *bio_list; 1258 1259 /* Stack plugging: */ 1260 struct blk_plug *plug; 1261 1262 /* VM state: */ 1263 struct reclaim_state *reclaim_state; 1264 1265 struct io_context *io_context; 1266 1267 #ifdef CONFIG_COMPACTION 1268 struct capture_control *capture_control; 1269 #endif 1270 /* Ptrace state: */ 1271 unsigned long ptrace_message; 1272 kernel_siginfo_t *last_siginfo; 1273 1274 struct task_io_accounting ioac; 1275 #ifdef CONFIG_PSI 1276 /* Pressure stall state */ 1277 unsigned int psi_flags; 1278 #endif 1279 #ifdef CONFIG_TASK_XACCT 1280 /* Accumulated RSS usage: */ 1281 u64 acct_rss_mem1; 1282 /* Accumulated virtual memory usage: */ 1283 u64 acct_vm_mem1; 1284 /* stime + utime since last update: */ 1285 u64 acct_timexpd; 1286 #endif 1287 #ifdef CONFIG_CPUSETS 1288 /* Protected by ->alloc_lock: */ 1289 nodemask_t mems_allowed; 1290 /* Sequence number to catch updates: */ 1291 seqcount_spinlock_t mems_allowed_seq; 1292 int cpuset_mem_spread_rotor; 1293 #endif 1294 #ifdef CONFIG_CGROUPS 1295 /* Control Group info protected by css_set_lock: */ 1296 struct css_set __rcu *cgroups; 1297 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1298 struct list_head cg_list; 1299 #endif 1300 #ifdef CONFIG_X86_CPU_RESCTRL 1301 u32 closid; 1302 u32 rmid; 1303 #endif 1304 #ifdef CONFIG_FUTEX 1305 struct robust_list_head __user *robust_list; 1306 #ifdef CONFIG_COMPAT 1307 struct compat_robust_list_head __user *compat_robust_list; 1308 #endif 1309 struct list_head pi_state_list; 1310 struct futex_pi_state *pi_state_cache; 1311 struct mutex futex_exit_mutex; 1312 unsigned int futex_state; 1313 #endif 1314 #ifdef CONFIG_PERF_EVENTS 1315 u8 perf_recursion[PERF_NR_CONTEXTS]; 1316 struct perf_event_context *perf_event_ctxp; 1317 struct mutex perf_event_mutex; 1318 struct list_head perf_event_list; 1319 #endif 1320 #ifdef CONFIG_DEBUG_PREEMPT 1321 unsigned long preempt_disable_ip; 1322 #endif 1323 #ifdef CONFIG_NUMA 1324 /* Protected by alloc_lock: */ 1325 struct mempolicy *mempolicy; 1326 short il_prev; 1327 u8 il_weight; 1328 short pref_node_fork; 1329 #endif 1330 #ifdef CONFIG_NUMA_BALANCING 1331 int numa_scan_seq; 1332 unsigned int numa_scan_period; 1333 unsigned int numa_scan_period_max; 1334 int numa_preferred_nid; 1335 unsigned long numa_migrate_retry; 1336 /* Migration stamp: */ 1337 u64 node_stamp; 1338 u64 last_task_numa_placement; 1339 u64 last_sum_exec_runtime; 1340 struct callback_head numa_work; 1341 1342 /* 1343 * This pointer is only modified for current in syscall and 1344 * pagefault context (and for tasks being destroyed), so it can be read 1345 * from any of the following contexts: 1346 * - RCU read-side critical section 1347 * - current->numa_group from everywhere 1348 * - task's runqueue locked, task not running 1349 */ 1350 struct numa_group __rcu *numa_group; 1351 1352 /* 1353 * numa_faults is an array split into four regions: 1354 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1355 * in this precise order. 1356 * 1357 * faults_memory: Exponential decaying average of faults on a per-node 1358 * basis. Scheduling placement decisions are made based on these 1359 * counts. The values remain static for the duration of a PTE scan. 1360 * faults_cpu: Track the nodes the process was running on when a NUMA 1361 * hinting fault was incurred. 1362 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1363 * during the current scan window. When the scan completes, the counts 1364 * in faults_memory and faults_cpu decay and these values are copied. 1365 */ 1366 unsigned long *numa_faults; 1367 unsigned long total_numa_faults; 1368 1369 /* 1370 * numa_faults_locality tracks if faults recorded during the last 1371 * scan window were remote/local or failed to migrate. The task scan 1372 * period is adapted based on the locality of the faults with different 1373 * weights depending on whether they were shared or private faults 1374 */ 1375 unsigned long numa_faults_locality[3]; 1376 1377 unsigned long numa_pages_migrated; 1378 #endif /* CONFIG_NUMA_BALANCING */ 1379 1380 #ifdef CONFIG_RSEQ 1381 struct rseq __user *rseq; 1382 u32 rseq_len; 1383 u32 rseq_sig; 1384 /* 1385 * RmW on rseq_event_mask must be performed atomically 1386 * with respect to preemption. 1387 */ 1388 unsigned long rseq_event_mask; 1389 # ifdef CONFIG_DEBUG_RSEQ 1390 /* 1391 * This is a place holder to save a copy of the rseq fields for 1392 * validation of read-only fields. The struct rseq has a 1393 * variable-length array at the end, so it cannot be used 1394 * directly. Reserve a size large enough for the known fields. 1395 */ 1396 char rseq_fields[sizeof(struct rseq)]; 1397 # endif 1398 #endif 1399 1400 #ifdef CONFIG_SCHED_MM_CID 1401 int mm_cid; /* Current cid in mm */ 1402 int last_mm_cid; /* Most recent cid in mm */ 1403 int migrate_from_cpu; 1404 int mm_cid_active; /* Whether cid bitmap is active */ 1405 struct callback_head cid_work; 1406 #endif 1407 1408 struct tlbflush_unmap_batch tlb_ubc; 1409 1410 /* Cache last used pipe for splice(): */ 1411 struct pipe_inode_info *splice_pipe; 1412 1413 struct page_frag task_frag; 1414 1415 #ifdef CONFIG_TASK_DELAY_ACCT 1416 struct task_delay_info *delays; 1417 #endif 1418 1419 #ifdef CONFIG_FAULT_INJECTION 1420 int make_it_fail; 1421 unsigned int fail_nth; 1422 #endif 1423 /* 1424 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1425 * balance_dirty_pages() for a dirty throttling pause: 1426 */ 1427 int nr_dirtied; 1428 int nr_dirtied_pause; 1429 /* Start of a write-and-pause period: */ 1430 unsigned long dirty_paused_when; 1431 1432 #ifdef CONFIG_LATENCYTOP 1433 int latency_record_count; 1434 struct latency_record latency_record[LT_SAVECOUNT]; 1435 #endif 1436 /* 1437 * Time slack values; these are used to round up poll() and 1438 * select() etc timeout values. These are in nanoseconds. 1439 */ 1440 u64 timer_slack_ns; 1441 u64 default_timer_slack_ns; 1442 1443 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1444 unsigned int kasan_depth; 1445 #endif 1446 1447 #ifdef CONFIG_KCSAN 1448 struct kcsan_ctx kcsan_ctx; 1449 #ifdef CONFIG_TRACE_IRQFLAGS 1450 struct irqtrace_events kcsan_save_irqtrace; 1451 #endif 1452 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1453 int kcsan_stack_depth; 1454 #endif 1455 #endif 1456 1457 #ifdef CONFIG_KMSAN 1458 struct kmsan_ctx kmsan_ctx; 1459 #endif 1460 1461 #if IS_ENABLED(CONFIG_KUNIT) 1462 struct kunit *kunit_test; 1463 #endif 1464 1465 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1466 /* Index of current stored address in ret_stack: */ 1467 int curr_ret_stack; 1468 int curr_ret_depth; 1469 1470 /* Stack of return addresses for return function tracing: */ 1471 unsigned long *ret_stack; 1472 1473 /* Timestamp for last schedule: */ 1474 unsigned long long ftrace_timestamp; 1475 unsigned long long ftrace_sleeptime; 1476 1477 /* 1478 * Number of functions that haven't been traced 1479 * because of depth overrun: 1480 */ 1481 atomic_t trace_overrun; 1482 1483 /* Pause tracing: */ 1484 atomic_t tracing_graph_pause; 1485 #endif 1486 1487 #ifdef CONFIG_TRACING 1488 /* Bitmask and counter of trace recursion: */ 1489 unsigned long trace_recursion; 1490 #endif /* CONFIG_TRACING */ 1491 1492 #ifdef CONFIG_KCOV 1493 /* See kernel/kcov.c for more details. */ 1494 1495 /* Coverage collection mode enabled for this task (0 if disabled): */ 1496 unsigned int kcov_mode; 1497 1498 /* Size of the kcov_area: */ 1499 unsigned int kcov_size; 1500 1501 /* Buffer for coverage collection: */ 1502 void *kcov_area; 1503 1504 /* KCOV descriptor wired with this task or NULL: */ 1505 struct kcov *kcov; 1506 1507 /* KCOV common handle for remote coverage collection: */ 1508 u64 kcov_handle; 1509 1510 /* KCOV sequence number: */ 1511 int kcov_sequence; 1512 1513 /* Collect coverage from softirq context: */ 1514 unsigned int kcov_softirq; 1515 #endif 1516 1517 #ifdef CONFIG_MEMCG_V1 1518 struct mem_cgroup *memcg_in_oom; 1519 #endif 1520 1521 #ifdef CONFIG_MEMCG 1522 /* Number of pages to reclaim on returning to userland: */ 1523 unsigned int memcg_nr_pages_over_high; 1524 1525 /* Used by memcontrol for targeted memcg charge: */ 1526 struct mem_cgroup *active_memcg; 1527 1528 /* Cache for current->cgroups->memcg->objcg lookups: */ 1529 struct obj_cgroup *objcg; 1530 #endif 1531 1532 #ifdef CONFIG_BLK_CGROUP 1533 struct gendisk *throttle_disk; 1534 #endif 1535 1536 #ifdef CONFIG_UPROBES 1537 struct uprobe_task *utask; 1538 #endif 1539 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1540 unsigned int sequential_io; 1541 unsigned int sequential_io_avg; 1542 #endif 1543 struct kmap_ctrl kmap_ctrl; 1544 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1545 unsigned long task_state_change; 1546 # ifdef CONFIG_PREEMPT_RT 1547 unsigned long saved_state_change; 1548 # endif 1549 #endif 1550 struct rcu_head rcu; 1551 refcount_t rcu_users; 1552 int pagefault_disabled; 1553 #ifdef CONFIG_MMU 1554 struct task_struct *oom_reaper_list; 1555 struct timer_list oom_reaper_timer; 1556 #endif 1557 #ifdef CONFIG_VMAP_STACK 1558 struct vm_struct *stack_vm_area; 1559 #endif 1560 #ifdef CONFIG_THREAD_INFO_IN_TASK 1561 /* A live task holds one reference: */ 1562 refcount_t stack_refcount; 1563 #endif 1564 #ifdef CONFIG_LIVEPATCH 1565 int patch_state; 1566 #endif 1567 #ifdef CONFIG_SECURITY 1568 /* Used by LSM modules for access restriction: */ 1569 void *security; 1570 #endif 1571 #ifdef CONFIG_BPF_SYSCALL 1572 /* Used by BPF task local storage */ 1573 struct bpf_local_storage __rcu *bpf_storage; 1574 /* Used for BPF run context */ 1575 struct bpf_run_ctx *bpf_ctx; 1576 #endif 1577 /* Used by BPF for per-TASK xdp storage */ 1578 struct bpf_net_context *bpf_net_context; 1579 1580 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1581 unsigned long lowest_stack; 1582 unsigned long prev_lowest_stack; 1583 #endif 1584 1585 #ifdef CONFIG_X86_MCE 1586 void __user *mce_vaddr; 1587 __u64 mce_kflags; 1588 u64 mce_addr; 1589 __u64 mce_ripv : 1, 1590 mce_whole_page : 1, 1591 __mce_reserved : 62; 1592 struct callback_head mce_kill_me; 1593 int mce_count; 1594 #endif 1595 1596 #ifdef CONFIG_KRETPROBES 1597 struct llist_head kretprobe_instances; 1598 #endif 1599 #ifdef CONFIG_RETHOOK 1600 struct llist_head rethooks; 1601 #endif 1602 1603 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1604 /* 1605 * If L1D flush is supported on mm context switch 1606 * then we use this callback head to queue kill work 1607 * to kill tasks that are not running on SMT disabled 1608 * cores 1609 */ 1610 struct callback_head l1d_flush_kill; 1611 #endif 1612 1613 #ifdef CONFIG_RV 1614 /* 1615 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1616 * If we find justification for more monitors, we can think 1617 * about adding more or developing a dynamic method. So far, 1618 * none of these are justified. 1619 */ 1620 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1621 #endif 1622 1623 #ifdef CONFIG_USER_EVENTS 1624 struct user_event_mm *user_event_mm; 1625 #endif 1626 1627 /* 1628 * New fields for task_struct should be added above here, so that 1629 * they are included in the randomized portion of task_struct. 1630 */ 1631 randomized_struct_fields_end 1632 1633 /* CPU-specific state of this task: */ 1634 struct thread_struct thread; 1635 1636 /* 1637 * WARNING: on x86, 'thread_struct' contains a variable-sized 1638 * structure. It *MUST* be at the end of 'task_struct'. 1639 * 1640 * Do not put anything below here! 1641 */ 1642 }; 1643 1644 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1645 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1646 1647 static inline unsigned int __task_state_index(unsigned int tsk_state, 1648 unsigned int tsk_exit_state) 1649 { 1650 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1651 1652 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1653 1654 if ((tsk_state & TASK_IDLE) == TASK_IDLE) 1655 state = TASK_REPORT_IDLE; 1656 1657 /* 1658 * We're lying here, but rather than expose a completely new task state 1659 * to userspace, we can make this appear as if the task has gone through 1660 * a regular rt_mutex_lock() call. 1661 * Report frozen tasks as uninterruptible. 1662 */ 1663 if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN)) 1664 state = TASK_UNINTERRUPTIBLE; 1665 1666 return fls(state); 1667 } 1668 1669 static inline unsigned int task_state_index(struct task_struct *tsk) 1670 { 1671 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1672 } 1673 1674 static inline char task_index_to_char(unsigned int state) 1675 { 1676 static const char state_char[] = "RSDTtXZPI"; 1677 1678 BUILD_BUG_ON(TASK_REPORT_MAX * 2 != 1 << (sizeof(state_char) - 1)); 1679 1680 return state_char[state]; 1681 } 1682 1683 static inline char task_state_to_char(struct task_struct *tsk) 1684 { 1685 return task_index_to_char(task_state_index(tsk)); 1686 } 1687 1688 extern struct pid *cad_pid; 1689 1690 /* 1691 * Per process flags 1692 */ 1693 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1694 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1695 #define PF_EXITING 0x00000004 /* Getting shut down */ 1696 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1697 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1698 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1699 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1700 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1701 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1702 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1703 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1704 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */ 1705 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1706 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1707 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1708 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1709 #define PF__HOLE__00010000 0x00010000 1710 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1711 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */ 1712 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */ 1713 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1714 * I am cleaning dirty pages from some other bdi. */ 1715 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1716 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1717 #define PF__HOLE__00800000 0x00800000 1718 #define PF__HOLE__01000000 0x01000000 1719 #define PF__HOLE__02000000 0x02000000 1720 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1721 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1722 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning. 1723 * See memalloc_pin_save() */ 1724 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */ 1725 #define PF__HOLE__40000000 0x40000000 1726 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1727 1728 /* 1729 * Only the _current_ task can read/write to tsk->flags, but other 1730 * tasks can access tsk->flags in readonly mode for example 1731 * with tsk_used_math (like during threaded core dumping). 1732 * There is however an exception to this rule during ptrace 1733 * or during fork: the ptracer task is allowed to write to the 1734 * child->flags of its traced child (same goes for fork, the parent 1735 * can write to the child->flags), because we're guaranteed the 1736 * child is not running and in turn not changing child->flags 1737 * at the same time the parent does it. 1738 */ 1739 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1740 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1741 #define clear_used_math() clear_stopped_child_used_math(current) 1742 #define set_used_math() set_stopped_child_used_math(current) 1743 1744 #define conditional_stopped_child_used_math(condition, child) \ 1745 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1746 1747 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1748 1749 #define copy_to_stopped_child_used_math(child) \ 1750 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1751 1752 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1753 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1754 #define used_math() tsk_used_math(current) 1755 1756 static __always_inline bool is_percpu_thread(void) 1757 { 1758 #ifdef CONFIG_SMP 1759 return (current->flags & PF_NO_SETAFFINITY) && 1760 (current->nr_cpus_allowed == 1); 1761 #else 1762 return true; 1763 #endif 1764 } 1765 1766 /* Per-process atomic flags. */ 1767 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1768 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1769 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1770 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1771 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1772 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1773 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1774 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1775 1776 #define TASK_PFA_TEST(name, func) \ 1777 static inline bool task_##func(struct task_struct *p) \ 1778 { return test_bit(PFA_##name, &p->atomic_flags); } 1779 1780 #define TASK_PFA_SET(name, func) \ 1781 static inline void task_set_##func(struct task_struct *p) \ 1782 { set_bit(PFA_##name, &p->atomic_flags); } 1783 1784 #define TASK_PFA_CLEAR(name, func) \ 1785 static inline void task_clear_##func(struct task_struct *p) \ 1786 { clear_bit(PFA_##name, &p->atomic_flags); } 1787 1788 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1789 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1790 1791 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1792 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1793 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1794 1795 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1796 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1797 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1798 1799 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1800 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1801 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1802 1803 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1804 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1805 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1806 1807 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1808 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1809 1810 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1811 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1812 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1813 1814 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1815 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1816 1817 static inline void 1818 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1819 { 1820 current->flags &= ~flags; 1821 current->flags |= orig_flags & flags; 1822 } 1823 1824 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1825 extern int task_can_attach(struct task_struct *p); 1826 extern int dl_bw_alloc(int cpu, u64 dl_bw); 1827 extern void dl_bw_free(int cpu, u64 dl_bw); 1828 #ifdef CONFIG_SMP 1829 1830 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */ 1831 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1832 1833 /** 1834 * set_cpus_allowed_ptr - set CPU affinity mask of a task 1835 * @p: the task 1836 * @new_mask: CPU affinity mask 1837 * 1838 * Return: zero if successful, or a negative error code 1839 */ 1840 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1841 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1842 extern void release_user_cpus_ptr(struct task_struct *p); 1843 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1844 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1845 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1846 #else 1847 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1848 { 1849 } 1850 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1851 { 1852 /* Opencoded cpumask_test_cpu(0, new_mask) to avoid dependency on cpumask.h */ 1853 if ((*cpumask_bits(new_mask) & 1) == 0) 1854 return -EINVAL; 1855 return 0; 1856 } 1857 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1858 { 1859 if (src->user_cpus_ptr) 1860 return -EINVAL; 1861 return 0; 1862 } 1863 static inline void release_user_cpus_ptr(struct task_struct *p) 1864 { 1865 WARN_ON(p->user_cpus_ptr); 1866 } 1867 1868 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1869 { 1870 return 0; 1871 } 1872 #endif 1873 1874 extern int yield_to(struct task_struct *p, bool preempt); 1875 extern void set_user_nice(struct task_struct *p, long nice); 1876 extern int task_prio(const struct task_struct *p); 1877 1878 /** 1879 * task_nice - return the nice value of a given task. 1880 * @p: the task in question. 1881 * 1882 * Return: The nice value [ -20 ... 0 ... 19 ]. 1883 */ 1884 static inline int task_nice(const struct task_struct *p) 1885 { 1886 return PRIO_TO_NICE((p)->static_prio); 1887 } 1888 1889 extern int can_nice(const struct task_struct *p, const int nice); 1890 extern int task_curr(const struct task_struct *p); 1891 extern int idle_cpu(int cpu); 1892 extern int available_idle_cpu(int cpu); 1893 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1894 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1895 extern void sched_set_fifo(struct task_struct *p); 1896 extern void sched_set_fifo_low(struct task_struct *p); 1897 extern void sched_set_normal(struct task_struct *p, int nice); 1898 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1899 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1900 extern struct task_struct *idle_task(int cpu); 1901 1902 /** 1903 * is_idle_task - is the specified task an idle task? 1904 * @p: the task in question. 1905 * 1906 * Return: 1 if @p is an idle task. 0 otherwise. 1907 */ 1908 static __always_inline bool is_idle_task(const struct task_struct *p) 1909 { 1910 return !!(p->flags & PF_IDLE); 1911 } 1912 1913 extern struct task_struct *curr_task(int cpu); 1914 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1915 1916 void yield(void); 1917 1918 union thread_union { 1919 struct task_struct task; 1920 #ifndef CONFIG_THREAD_INFO_IN_TASK 1921 struct thread_info thread_info; 1922 #endif 1923 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1924 }; 1925 1926 #ifndef CONFIG_THREAD_INFO_IN_TASK 1927 extern struct thread_info init_thread_info; 1928 #endif 1929 1930 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1931 1932 #ifdef CONFIG_THREAD_INFO_IN_TASK 1933 # define task_thread_info(task) (&(task)->thread_info) 1934 #else 1935 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1936 #endif 1937 1938 /* 1939 * find a task by one of its numerical ids 1940 * 1941 * find_task_by_pid_ns(): 1942 * finds a task by its pid in the specified namespace 1943 * find_task_by_vpid(): 1944 * finds a task by its virtual pid 1945 * 1946 * see also find_vpid() etc in include/linux/pid.h 1947 */ 1948 1949 extern struct task_struct *find_task_by_vpid(pid_t nr); 1950 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1951 1952 /* 1953 * find a task by its virtual pid and get the task struct 1954 */ 1955 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1956 1957 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1958 extern int wake_up_process(struct task_struct *tsk); 1959 extern void wake_up_new_task(struct task_struct *tsk); 1960 1961 #ifdef CONFIG_SMP 1962 extern void kick_process(struct task_struct *tsk); 1963 #else 1964 static inline void kick_process(struct task_struct *tsk) { } 1965 #endif 1966 1967 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1968 #define set_task_comm(tsk, from) ({ \ 1969 BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \ 1970 __set_task_comm(tsk, from, false); \ 1971 }) 1972 1973 /* 1974 * - Why not use task_lock()? 1975 * User space can randomly change their names anyway, so locking for readers 1976 * doesn't make sense. For writers, locking is probably necessary, as a race 1977 * condition could lead to long-term mixed results. 1978 * The strscpy_pad() in __set_task_comm() can ensure that the task comm is 1979 * always NUL-terminated and zero-padded. Therefore the race condition between 1980 * reader and writer is not an issue. 1981 * 1982 * - BUILD_BUG_ON() can help prevent the buf from being truncated. 1983 * Since the callers don't perform any return value checks, this safeguard is 1984 * necessary. 1985 */ 1986 #define get_task_comm(buf, tsk) ({ \ 1987 BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \ 1988 strscpy_pad(buf, (tsk)->comm); \ 1989 buf; \ 1990 }) 1991 1992 #ifdef CONFIG_SMP 1993 static __always_inline void scheduler_ipi(void) 1994 { 1995 /* 1996 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1997 * TIF_NEED_RESCHED remotely (for the first time) will also send 1998 * this IPI. 1999 */ 2000 preempt_fold_need_resched(); 2001 } 2002 #else 2003 static inline void scheduler_ipi(void) { } 2004 #endif 2005 2006 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 2007 2008 /* 2009 * Set thread flags in other task's structures. 2010 * See asm/thread_info.h for TIF_xxxx flags available: 2011 */ 2012 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2013 { 2014 set_ti_thread_flag(task_thread_info(tsk), flag); 2015 } 2016 2017 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2018 { 2019 clear_ti_thread_flag(task_thread_info(tsk), flag); 2020 } 2021 2022 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2023 bool value) 2024 { 2025 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2026 } 2027 2028 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2029 { 2030 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2031 } 2032 2033 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2034 { 2035 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2036 } 2037 2038 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2039 { 2040 return test_ti_thread_flag(task_thread_info(tsk), flag); 2041 } 2042 2043 static inline void set_tsk_need_resched(struct task_struct *tsk) 2044 { 2045 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2046 } 2047 2048 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2049 { 2050 atomic_long_andnot(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY, 2051 (atomic_long_t *)&task_thread_info(tsk)->flags); 2052 } 2053 2054 static inline int test_tsk_need_resched(struct task_struct *tsk) 2055 { 2056 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2057 } 2058 2059 /* 2060 * cond_resched() and cond_resched_lock(): latency reduction via 2061 * explicit rescheduling in places that are safe. The return 2062 * value indicates whether a reschedule was done in fact. 2063 * cond_resched_lock() will drop the spinlock before scheduling, 2064 */ 2065 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2066 extern int __cond_resched(void); 2067 2068 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2069 2070 void sched_dynamic_klp_enable(void); 2071 void sched_dynamic_klp_disable(void); 2072 2073 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2074 2075 static __always_inline int _cond_resched(void) 2076 { 2077 return static_call_mod(cond_resched)(); 2078 } 2079 2080 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2081 2082 extern int dynamic_cond_resched(void); 2083 2084 static __always_inline int _cond_resched(void) 2085 { 2086 return dynamic_cond_resched(); 2087 } 2088 2089 #else /* !CONFIG_PREEMPTION */ 2090 2091 static inline int _cond_resched(void) 2092 { 2093 klp_sched_try_switch(); 2094 return __cond_resched(); 2095 } 2096 2097 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2098 2099 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2100 2101 static inline int _cond_resched(void) 2102 { 2103 klp_sched_try_switch(); 2104 return 0; 2105 } 2106 2107 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2108 2109 #define cond_resched() ({ \ 2110 __might_resched(__FILE__, __LINE__, 0); \ 2111 _cond_resched(); \ 2112 }) 2113 2114 extern int __cond_resched_lock(spinlock_t *lock); 2115 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2116 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2117 2118 #define MIGHT_RESCHED_RCU_SHIFT 8 2119 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2120 2121 #ifndef CONFIG_PREEMPT_RT 2122 /* 2123 * Non RT kernels have an elevated preempt count due to the held lock, 2124 * but are not allowed to be inside a RCU read side critical section 2125 */ 2126 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2127 #else 2128 /* 2129 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2130 * cond_resched*lock() has to take that into account because it checks for 2131 * preempt_count() and rcu_preempt_depth(). 2132 */ 2133 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2134 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2135 #endif 2136 2137 #define cond_resched_lock(lock) ({ \ 2138 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2139 __cond_resched_lock(lock); \ 2140 }) 2141 2142 #define cond_resched_rwlock_read(lock) ({ \ 2143 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2144 __cond_resched_rwlock_read(lock); \ 2145 }) 2146 2147 #define cond_resched_rwlock_write(lock) ({ \ 2148 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2149 __cond_resched_rwlock_write(lock); \ 2150 }) 2151 2152 static __always_inline bool need_resched(void) 2153 { 2154 return unlikely(tif_need_resched()); 2155 } 2156 2157 /* 2158 * Wrappers for p->thread_info->cpu access. No-op on UP. 2159 */ 2160 #ifdef CONFIG_SMP 2161 2162 static inline unsigned int task_cpu(const struct task_struct *p) 2163 { 2164 return READ_ONCE(task_thread_info(p)->cpu); 2165 } 2166 2167 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2168 2169 #else 2170 2171 static inline unsigned int task_cpu(const struct task_struct *p) 2172 { 2173 return 0; 2174 } 2175 2176 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2177 { 2178 } 2179 2180 #endif /* CONFIG_SMP */ 2181 2182 static inline bool task_is_runnable(struct task_struct *p) 2183 { 2184 return p->on_rq && !p->se.sched_delayed; 2185 } 2186 2187 extern bool sched_task_on_rq(struct task_struct *p); 2188 extern unsigned long get_wchan(struct task_struct *p); 2189 extern struct task_struct *cpu_curr_snapshot(int cpu); 2190 2191 #include <linux/spinlock.h> 2192 2193 /* 2194 * In order to reduce various lock holder preemption latencies provide an 2195 * interface to see if a vCPU is currently running or not. 2196 * 2197 * This allows us to terminate optimistic spin loops and block, analogous to 2198 * the native optimistic spin heuristic of testing if the lock owner task is 2199 * running or not. 2200 */ 2201 #ifndef vcpu_is_preempted 2202 static inline bool vcpu_is_preempted(int cpu) 2203 { 2204 return false; 2205 } 2206 #endif 2207 2208 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2209 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2210 2211 #ifndef TASK_SIZE_OF 2212 #define TASK_SIZE_OF(tsk) TASK_SIZE 2213 #endif 2214 2215 #ifdef CONFIG_SMP 2216 static inline bool owner_on_cpu(struct task_struct *owner) 2217 { 2218 /* 2219 * As lock holder preemption issue, we both skip spinning if 2220 * task is not on cpu or its cpu is preempted 2221 */ 2222 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2223 } 2224 2225 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2226 unsigned long sched_cpu_util(int cpu); 2227 #endif /* CONFIG_SMP */ 2228 2229 #ifdef CONFIG_SCHED_CORE 2230 extern void sched_core_free(struct task_struct *tsk); 2231 extern void sched_core_fork(struct task_struct *p); 2232 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2233 unsigned long uaddr); 2234 extern int sched_core_idle_cpu(int cpu); 2235 #else 2236 static inline void sched_core_free(struct task_struct *tsk) { } 2237 static inline void sched_core_fork(struct task_struct *p) { } 2238 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); } 2239 #endif 2240 2241 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2242 2243 #ifdef CONFIG_MEM_ALLOC_PROFILING 2244 static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag) 2245 { 2246 swap(current->alloc_tag, tag); 2247 return tag; 2248 } 2249 2250 static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old) 2251 { 2252 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 2253 WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n"); 2254 #endif 2255 current->alloc_tag = old; 2256 } 2257 #else 2258 #define alloc_tag_save(_tag) NULL 2259 #define alloc_tag_restore(_tag, _old) do {} while (0) 2260 #endif 2261 2262 #endif 2263