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