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