1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SCHED_H 3 #define _LINUX_SCHED_H 4 5 /* 6 * Define 'struct task_struct' and provide the main scheduler 7 * APIs (schedule(), wakeup variants, etc.) 8 */ 9 10 #include <uapi/linux/sched.h> 11 12 #include <asm/current.h> 13 #include <asm/processor.h> 14 #include <linux/thread_info.h> 15 #include <linux/preempt.h> 16 #include <linux/cpumask.h> 17 18 #include <linux/cache.h> 19 #include <linux/irqflags_types.h> 20 #include <linux/smp_types.h> 21 #include <linux/pid_types.h> 22 #include <linux/sem_types.h> 23 #include <linux/shm.h> 24 #include <linux/kmsan_types.h> 25 #include <linux/mutex_types.h> 26 #include <linux/plist_types.h> 27 #include <linux/hrtimer_types.h> 28 #include <linux/timer_types.h> 29 #include <linux/seccomp_types.h> 30 #include <linux/nodemask_types.h> 31 #include <linux/refcount_types.h> 32 #include <linux/resource.h> 33 #include <linux/latencytop.h> 34 #include <linux/sched/prio.h> 35 #include <linux/sched/types.h> 36 #include <linux/signal_types.h> 37 #include <linux/syscall_user_dispatch_types.h> 38 #include <linux/mm_types_task.h> 39 #include <linux/task_io_accounting.h> 40 #include <linux/posix-timers_types.h> 41 #include <linux/restart_block.h> 42 #include <uapi/linux/rseq.h> 43 #include <linux/seqlock_types.h> 44 #include <linux/kcsan.h> 45 #include <linux/rv.h> 46 #include <linux/livepatch_sched.h> 47 #include <linux/uidgid_types.h> 48 #include <asm/kmap_size.h> 49 50 /* task_struct member predeclarations (sorted alphabetically): */ 51 struct audit_context; 52 struct bio_list; 53 struct blk_plug; 54 struct bpf_local_storage; 55 struct bpf_run_ctx; 56 struct capture_control; 57 struct cfs_rq; 58 struct fs_struct; 59 struct futex_pi_state; 60 struct io_context; 61 struct io_uring_task; 62 struct mempolicy; 63 struct nameidata; 64 struct nsproxy; 65 struct perf_event_context; 66 struct pid_namespace; 67 struct pipe_inode_info; 68 struct rcu_node; 69 struct reclaim_state; 70 struct robust_list_head; 71 struct root_domain; 72 struct rq; 73 struct sched_attr; 74 struct sched_dl_entity; 75 struct seq_file; 76 struct sighand_struct; 77 struct signal_struct; 78 struct task_delay_info; 79 struct task_group; 80 struct task_struct; 81 struct user_event_mm; 82 83 /* 84 * Task state bitmask. NOTE! These bits are also 85 * encoded in fs/proc/array.c: get_task_state(). 86 * 87 * We have two separate sets of flags: task->__state 88 * is about runnability, while task->exit_state are 89 * about the task exiting. Confusing, but this way 90 * modifying one set can't modify the other one by 91 * mistake. 92 */ 93 94 /* Used in tsk->__state: */ 95 #define TASK_RUNNING 0x00000000 96 #define TASK_INTERRUPTIBLE 0x00000001 97 #define TASK_UNINTERRUPTIBLE 0x00000002 98 #define __TASK_STOPPED 0x00000004 99 #define __TASK_TRACED 0x00000008 100 /* Used in tsk->exit_state: */ 101 #define EXIT_DEAD 0x00000010 102 #define EXIT_ZOMBIE 0x00000020 103 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 104 /* Used in tsk->__state again: */ 105 #define TASK_PARKED 0x00000040 106 #define TASK_DEAD 0x00000080 107 #define TASK_WAKEKILL 0x00000100 108 #define TASK_WAKING 0x00000200 109 #define TASK_NOLOAD 0x00000400 110 #define TASK_NEW 0x00000800 111 #define TASK_RTLOCK_WAIT 0x00001000 112 #define TASK_FREEZABLE 0x00002000 113 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 114 #define TASK_FROZEN 0x00008000 115 #define TASK_STATE_MAX 0x00010000 116 117 #define TASK_ANY (TASK_STATE_MAX-1) 118 119 /* 120 * DO NOT ADD ANY NEW USERS ! 121 */ 122 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 123 124 /* Convenience macros for the sake of set_current_state: */ 125 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 126 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 127 #define TASK_TRACED __TASK_TRACED 128 129 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 130 131 /* Convenience macros for the sake of wake_up(): */ 132 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 133 134 /* get_task_state(): */ 135 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 136 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 137 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 138 TASK_PARKED) 139 140 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 141 142 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 143 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 144 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 145 146 /* 147 * Special states are those that do not use the normal wait-loop pattern. See 148 * the comment with set_special_state(). 149 */ 150 #define is_special_task_state(state) \ 151 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 152 153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 154 # define debug_normal_state_change(state_value) \ 155 do { \ 156 WARN_ON_ONCE(is_special_task_state(state_value)); \ 157 current->task_state_change = _THIS_IP_; \ 158 } while (0) 159 160 # define debug_special_state_change(state_value) \ 161 do { \ 162 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 163 current->task_state_change = _THIS_IP_; \ 164 } while (0) 165 166 # define debug_rtlock_wait_set_state() \ 167 do { \ 168 current->saved_state_change = current->task_state_change;\ 169 current->task_state_change = _THIS_IP_; \ 170 } while (0) 171 172 # define debug_rtlock_wait_restore_state() \ 173 do { \ 174 current->task_state_change = current->saved_state_change;\ 175 } while (0) 176 177 #else 178 # define debug_normal_state_change(cond) do { } while (0) 179 # define debug_special_state_change(cond) do { } while (0) 180 # define debug_rtlock_wait_set_state() do { } while (0) 181 # define debug_rtlock_wait_restore_state() do { } while (0) 182 #endif 183 184 /* 185 * set_current_state() includes a barrier so that the write of current->__state 186 * is correctly serialised wrt the caller's subsequent test of whether to 187 * actually sleep: 188 * 189 * for (;;) { 190 * set_current_state(TASK_UNINTERRUPTIBLE); 191 * if (CONDITION) 192 * break; 193 * 194 * schedule(); 195 * } 196 * __set_current_state(TASK_RUNNING); 197 * 198 * If the caller does not need such serialisation (because, for instance, the 199 * CONDITION test and condition change and wakeup are under the same lock) then 200 * use __set_current_state(). 201 * 202 * The above is typically ordered against the wakeup, which does: 203 * 204 * CONDITION = 1; 205 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 206 * 207 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 208 * accessing p->__state. 209 * 210 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is, 211 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 212 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 213 * 214 * However, with slightly different timing the wakeup TASK_RUNNING store can 215 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 216 * a problem either because that will result in one extra go around the loop 217 * and our @cond test will save the day. 218 * 219 * Also see the comments of try_to_wake_up(). 220 */ 221 #define __set_current_state(state_value) \ 222 do { \ 223 debug_normal_state_change((state_value)); \ 224 WRITE_ONCE(current->__state, (state_value)); \ 225 } while (0) 226 227 #define set_current_state(state_value) \ 228 do { \ 229 debug_normal_state_change((state_value)); \ 230 smp_store_mb(current->__state, (state_value)); \ 231 } while (0) 232 233 /* 234 * set_special_state() should be used for those states when the blocking task 235 * can not use the regular condition based wait-loop. In that case we must 236 * serialize against wakeups such that any possible in-flight TASK_RUNNING 237 * stores will not collide with our state change. 238 */ 239 #define set_special_state(state_value) \ 240 do { \ 241 unsigned long flags; /* may shadow */ \ 242 \ 243 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 244 debug_special_state_change((state_value)); \ 245 WRITE_ONCE(current->__state, (state_value)); \ 246 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 247 } while (0) 248 249 /* 250 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 251 * 252 * RT's spin/rwlock substitutions are state preserving. The state of the 253 * task when blocking on the lock is saved in task_struct::saved_state and 254 * restored after the lock has been acquired. These operations are 255 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 256 * lock related wakeups while the task is blocked on the lock are 257 * redirected to operate on task_struct::saved_state to ensure that these 258 * are not dropped. On restore task_struct::saved_state is set to 259 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 260 * 261 * The lock operation looks like this: 262 * 263 * current_save_and_set_rtlock_wait_state(); 264 * for (;;) { 265 * if (try_lock()) 266 * break; 267 * raw_spin_unlock_irq(&lock->wait_lock); 268 * schedule_rtlock(); 269 * raw_spin_lock_irq(&lock->wait_lock); 270 * set_current_state(TASK_RTLOCK_WAIT); 271 * } 272 * current_restore_rtlock_saved_state(); 273 */ 274 #define current_save_and_set_rtlock_wait_state() \ 275 do { \ 276 lockdep_assert_irqs_disabled(); \ 277 raw_spin_lock(¤t->pi_lock); \ 278 current->saved_state = current->__state; \ 279 debug_rtlock_wait_set_state(); \ 280 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 281 raw_spin_unlock(¤t->pi_lock); \ 282 } while (0); 283 284 #define current_restore_rtlock_saved_state() \ 285 do { \ 286 lockdep_assert_irqs_disabled(); \ 287 raw_spin_lock(¤t->pi_lock); \ 288 debug_rtlock_wait_restore_state(); \ 289 WRITE_ONCE(current->__state, current->saved_state); \ 290 current->saved_state = TASK_RUNNING; \ 291 raw_spin_unlock(¤t->pi_lock); \ 292 } while (0); 293 294 #define get_current_state() READ_ONCE(current->__state) 295 296 /* 297 * Define the task command name length as enum, then it can be visible to 298 * BPF programs. 299 */ 300 enum { 301 TASK_COMM_LEN = 16, 302 }; 303 304 extern void sched_tick(void); 305 306 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 307 308 extern long schedule_timeout(long timeout); 309 extern long schedule_timeout_interruptible(long timeout); 310 extern long schedule_timeout_killable(long timeout); 311 extern long schedule_timeout_uninterruptible(long timeout); 312 extern long schedule_timeout_idle(long timeout); 313 asmlinkage void schedule(void); 314 extern void schedule_preempt_disabled(void); 315 asmlinkage void preempt_schedule_irq(void); 316 #ifdef CONFIG_PREEMPT_RT 317 extern void schedule_rtlock(void); 318 #endif 319 320 extern int __must_check io_schedule_prepare(void); 321 extern void io_schedule_finish(int token); 322 extern long io_schedule_timeout(long timeout); 323 extern void io_schedule(void); 324 325 /** 326 * struct prev_cputime - snapshot of system and user cputime 327 * @utime: time spent in user mode 328 * @stime: time spent in system mode 329 * @lock: protects the above two fields 330 * 331 * Stores previous user/system time values such that we can guarantee 332 * monotonicity. 333 */ 334 struct prev_cputime { 335 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 336 u64 utime; 337 u64 stime; 338 raw_spinlock_t lock; 339 #endif 340 }; 341 342 enum vtime_state { 343 /* Task is sleeping or running in a CPU with VTIME inactive: */ 344 VTIME_INACTIVE = 0, 345 /* Task is idle */ 346 VTIME_IDLE, 347 /* Task runs in kernelspace in a CPU with VTIME active: */ 348 VTIME_SYS, 349 /* Task runs in userspace in a CPU with VTIME active: */ 350 VTIME_USER, 351 /* Task runs as guests in a CPU with VTIME active: */ 352 VTIME_GUEST, 353 }; 354 355 struct vtime { 356 seqcount_t seqcount; 357 unsigned long long starttime; 358 enum vtime_state state; 359 unsigned int cpu; 360 u64 utime; 361 u64 stime; 362 u64 gtime; 363 }; 364 365 /* 366 * Utilization clamp constraints. 367 * @UCLAMP_MIN: Minimum utilization 368 * @UCLAMP_MAX: Maximum utilization 369 * @UCLAMP_CNT: Utilization clamp constraints count 370 */ 371 enum uclamp_id { 372 UCLAMP_MIN = 0, 373 UCLAMP_MAX, 374 UCLAMP_CNT 375 }; 376 377 #ifdef CONFIG_SMP 378 extern struct root_domain def_root_domain; 379 extern struct mutex sched_domains_mutex; 380 #endif 381 382 struct sched_param { 383 int sched_priority; 384 }; 385 386 struct sched_info { 387 #ifdef CONFIG_SCHED_INFO 388 /* Cumulative counters: */ 389 390 /* # of times we have run on this CPU: */ 391 unsigned long pcount; 392 393 /* Time spent waiting on a runqueue: */ 394 unsigned long long run_delay; 395 396 /* Timestamps: */ 397 398 /* When did we last run on a CPU? */ 399 unsigned long long last_arrival; 400 401 /* When were we last queued to run? */ 402 unsigned long long last_queued; 403 404 #endif /* CONFIG_SCHED_INFO */ 405 }; 406 407 /* 408 * Integer metrics need fixed point arithmetic, e.g., sched/fair 409 * has a few: load, load_avg, util_avg, freq, and capacity. 410 * 411 * We define a basic fixed point arithmetic range, and then formalize 412 * all these metrics based on that basic range. 413 */ 414 # define SCHED_FIXEDPOINT_SHIFT 10 415 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 416 417 /* Increase resolution of cpu_capacity calculations */ 418 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 419 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 420 421 struct load_weight { 422 unsigned long weight; 423 u32 inv_weight; 424 }; 425 426 /* 427 * The load/runnable/util_avg accumulates an infinite geometric series 428 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 429 * 430 * [load_avg definition] 431 * 432 * load_avg = runnable% * scale_load_down(load) 433 * 434 * [runnable_avg definition] 435 * 436 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 437 * 438 * [util_avg definition] 439 * 440 * util_avg = running% * SCHED_CAPACITY_SCALE 441 * 442 * where runnable% is the time ratio that a sched_entity is runnable and 443 * running% the time ratio that a sched_entity is running. 444 * 445 * For cfs_rq, they are the aggregated values of all runnable and blocked 446 * sched_entities. 447 * 448 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 449 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 450 * for computing those signals (see update_rq_clock_pelt()) 451 * 452 * N.B., the above ratios (runnable% and running%) themselves are in the 453 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 454 * to as large a range as necessary. This is for example reflected by 455 * util_avg's SCHED_CAPACITY_SCALE. 456 * 457 * [Overflow issue] 458 * 459 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 460 * with the highest load (=88761), always runnable on a single cfs_rq, 461 * and should not overflow as the number already hits PID_MAX_LIMIT. 462 * 463 * For all other cases (including 32-bit kernels), struct load_weight's 464 * weight will overflow first before we do, because: 465 * 466 * Max(load_avg) <= Max(load.weight) 467 * 468 * Then it is the load_weight's responsibility to consider overflow 469 * issues. 470 */ 471 struct sched_avg { 472 u64 last_update_time; 473 u64 load_sum; 474 u64 runnable_sum; 475 u32 util_sum; 476 u32 period_contrib; 477 unsigned long load_avg; 478 unsigned long runnable_avg; 479 unsigned long util_avg; 480 unsigned int util_est; 481 } ____cacheline_aligned; 482 483 /* 484 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 485 * updates. When a task is dequeued, its util_est should not be updated if its 486 * util_avg has not been updated in the meantime. 487 * This information is mapped into the MSB bit of util_est at dequeue time. 488 * Since max value of util_est for a task is 1024 (PELT util_avg for a task) 489 * it is safe to use MSB. 490 */ 491 #define UTIL_EST_WEIGHT_SHIFT 2 492 #define UTIL_AVG_UNCHANGED 0x80000000 493 494 struct sched_statistics { 495 #ifdef CONFIG_SCHEDSTATS 496 u64 wait_start; 497 u64 wait_max; 498 u64 wait_count; 499 u64 wait_sum; 500 u64 iowait_count; 501 u64 iowait_sum; 502 503 u64 sleep_start; 504 u64 sleep_max; 505 s64 sum_sleep_runtime; 506 507 u64 block_start; 508 u64 block_max; 509 s64 sum_block_runtime; 510 511 s64 exec_max; 512 u64 slice_max; 513 514 u64 nr_migrations_cold; 515 u64 nr_failed_migrations_affine; 516 u64 nr_failed_migrations_running; 517 u64 nr_failed_migrations_hot; 518 u64 nr_forced_migrations; 519 520 u64 nr_wakeups; 521 u64 nr_wakeups_sync; 522 u64 nr_wakeups_migrate; 523 u64 nr_wakeups_local; 524 u64 nr_wakeups_remote; 525 u64 nr_wakeups_affine; 526 u64 nr_wakeups_affine_attempts; 527 u64 nr_wakeups_passive; 528 u64 nr_wakeups_idle; 529 530 #ifdef CONFIG_SCHED_CORE 531 u64 core_forceidle_sum; 532 #endif 533 #endif /* CONFIG_SCHEDSTATS */ 534 } ____cacheline_aligned; 535 536 struct sched_entity { 537 /* For load-balancing: */ 538 struct load_weight load; 539 struct rb_node run_node; 540 u64 deadline; 541 u64 min_vruntime; 542 543 struct list_head group_node; 544 unsigned int on_rq; 545 546 u64 exec_start; 547 u64 sum_exec_runtime; 548 u64 prev_sum_exec_runtime; 549 u64 vruntime; 550 s64 vlag; 551 u64 slice; 552 553 u64 nr_migrations; 554 555 #ifdef CONFIG_FAIR_GROUP_SCHED 556 int depth; 557 struct sched_entity *parent; 558 /* rq on which this entity is (to be) queued: */ 559 struct cfs_rq *cfs_rq; 560 /* rq "owned" by this entity/group: */ 561 struct cfs_rq *my_q; 562 /* cached value of my_q->h_nr_running */ 563 unsigned long runnable_weight; 564 #endif 565 566 #ifdef CONFIG_SMP 567 /* 568 * Per entity load average tracking. 569 * 570 * Put into separate cache line so it does not 571 * collide with read-mostly values above. 572 */ 573 struct sched_avg avg; 574 #endif 575 }; 576 577 struct sched_rt_entity { 578 struct list_head run_list; 579 unsigned long timeout; 580 unsigned long watchdog_stamp; 581 unsigned int time_slice; 582 unsigned short on_rq; 583 unsigned short on_list; 584 585 struct sched_rt_entity *back; 586 #ifdef CONFIG_RT_GROUP_SCHED 587 struct sched_rt_entity *parent; 588 /* rq on which this entity is (to be) queued: */ 589 struct rt_rq *rt_rq; 590 /* rq "owned" by this entity/group: */ 591 struct rt_rq *my_q; 592 #endif 593 } __randomize_layout; 594 595 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *); 596 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *); 597 598 struct sched_dl_entity { 599 struct rb_node rb_node; 600 601 /* 602 * Original scheduling parameters. Copied here from sched_attr 603 * during sched_setattr(), they will remain the same until 604 * the next sched_setattr(). 605 */ 606 u64 dl_runtime; /* Maximum runtime for each instance */ 607 u64 dl_deadline; /* Relative deadline of each instance */ 608 u64 dl_period; /* Separation of two instances (period) */ 609 u64 dl_bw; /* dl_runtime / dl_period */ 610 u64 dl_density; /* dl_runtime / dl_deadline */ 611 612 /* 613 * Actual scheduling parameters. Initialized with the values above, 614 * they are continuously updated during task execution. Note that 615 * the remaining runtime could be < 0 in case we are in overrun. 616 */ 617 s64 runtime; /* Remaining runtime for this instance */ 618 u64 deadline; /* Absolute deadline for this instance */ 619 unsigned int flags; /* Specifying the scheduler behaviour */ 620 621 /* 622 * Some bool flags: 623 * 624 * @dl_throttled tells if we exhausted the runtime. If so, the 625 * task has to wait for a replenishment to be performed at the 626 * next firing of dl_timer. 627 * 628 * @dl_yielded tells if task gave up the CPU before consuming 629 * all its available runtime during the last job. 630 * 631 * @dl_non_contending tells if the task is inactive while still 632 * contributing to the active utilization. In other words, it 633 * indicates if the inactive timer has been armed and its handler 634 * has not been executed yet. This flag is useful to avoid race 635 * conditions between the inactive timer handler and the wakeup 636 * code. 637 * 638 * @dl_overrun tells if the task asked to be informed about runtime 639 * overruns. 640 */ 641 unsigned int dl_throttled : 1; 642 unsigned int dl_yielded : 1; 643 unsigned int dl_non_contending : 1; 644 unsigned int dl_overrun : 1; 645 unsigned int dl_server : 1; 646 647 /* 648 * Bandwidth enforcement timer. Each -deadline task has its 649 * own bandwidth to be enforced, thus we need one timer per task. 650 */ 651 struct hrtimer dl_timer; 652 653 /* 654 * Inactive timer, responsible for decreasing the active utilization 655 * at the "0-lag time". When a -deadline task blocks, it contributes 656 * to GRUB's active utilization until the "0-lag time", hence a 657 * timer is needed to decrease the active utilization at the correct 658 * time. 659 */ 660 struct hrtimer inactive_timer; 661 662 /* 663 * Bits for DL-server functionality. Also see the comment near 664 * dl_server_update(). 665 * 666 * @rq the runqueue this server is for 667 * 668 * @server_has_tasks() returns true if @server_pick return a 669 * runnable task. 670 */ 671 struct rq *rq; 672 dl_server_has_tasks_f server_has_tasks; 673 dl_server_pick_f server_pick; 674 675 #ifdef CONFIG_RT_MUTEXES 676 /* 677 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 678 * pi_se points to the donor, otherwise points to the dl_se it belongs 679 * to (the original one/itself). 680 */ 681 struct sched_dl_entity *pi_se; 682 #endif 683 }; 684 685 #ifdef CONFIG_UCLAMP_TASK 686 /* Number of utilization clamp buckets (shorter alias) */ 687 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 688 689 /* 690 * Utilization clamp for a scheduling entity 691 * @value: clamp value "assigned" to a se 692 * @bucket_id: bucket index corresponding to the "assigned" value 693 * @active: the se is currently refcounted in a rq's bucket 694 * @user_defined: the requested clamp value comes from user-space 695 * 696 * The bucket_id is the index of the clamp bucket matching the clamp value 697 * which is pre-computed and stored to avoid expensive integer divisions from 698 * the fast path. 699 * 700 * The active bit is set whenever a task has got an "effective" value assigned, 701 * which can be different from the clamp value "requested" from user-space. 702 * This allows to know a task is refcounted in the rq's bucket corresponding 703 * to the "effective" bucket_id. 704 * 705 * The user_defined bit is set whenever a task has got a task-specific clamp 706 * value requested from userspace, i.e. the system defaults apply to this task 707 * just as a restriction. This allows to relax default clamps when a less 708 * restrictive task-specific value has been requested, thus allowing to 709 * implement a "nice" semantic. For example, a task running with a 20% 710 * default boost can still drop its own boosting to 0%. 711 */ 712 struct uclamp_se { 713 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 714 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 715 unsigned int active : 1; 716 unsigned int user_defined : 1; 717 }; 718 #endif /* CONFIG_UCLAMP_TASK */ 719 720 union rcu_special { 721 struct { 722 u8 blocked; 723 u8 need_qs; 724 u8 exp_hint; /* Hint for performance. */ 725 u8 need_mb; /* Readers need smp_mb(). */ 726 } b; /* Bits. */ 727 u32 s; /* Set of bits. */ 728 }; 729 730 enum perf_event_task_context { 731 perf_invalid_context = -1, 732 perf_hw_context = 0, 733 perf_sw_context, 734 perf_nr_task_contexts, 735 }; 736 737 struct wake_q_node { 738 struct wake_q_node *next; 739 }; 740 741 struct kmap_ctrl { 742 #ifdef CONFIG_KMAP_LOCAL 743 int idx; 744 pte_t pteval[KM_MAX_IDX]; 745 #endif 746 }; 747 748 struct task_struct { 749 #ifdef CONFIG_THREAD_INFO_IN_TASK 750 /* 751 * For reasons of header soup (see current_thread_info()), this 752 * must be the first element of task_struct. 753 */ 754 struct thread_info thread_info; 755 #endif 756 unsigned int __state; 757 758 /* saved state for "spinlock sleepers" */ 759 unsigned int saved_state; 760 761 /* 762 * This begins the randomizable portion of task_struct. Only 763 * scheduling-critical items should be added above here. 764 */ 765 randomized_struct_fields_start 766 767 void *stack; 768 refcount_t usage; 769 /* Per task flags (PF_*), defined further below: */ 770 unsigned int flags; 771 unsigned int ptrace; 772 773 #ifdef CONFIG_MEM_ALLOC_PROFILING 774 struct alloc_tag *alloc_tag; 775 #endif 776 777 #ifdef CONFIG_SMP 778 int on_cpu; 779 struct __call_single_node wake_entry; 780 unsigned int wakee_flips; 781 unsigned long wakee_flip_decay_ts; 782 struct task_struct *last_wakee; 783 784 /* 785 * recent_used_cpu is initially set as the last CPU used by a task 786 * that wakes affine another task. Waker/wakee relationships can 787 * push tasks around a CPU where each wakeup moves to the next one. 788 * Tracking a recently used CPU allows a quick search for a recently 789 * used CPU that may be idle. 790 */ 791 int recent_used_cpu; 792 int wake_cpu; 793 #endif 794 int on_rq; 795 796 int prio; 797 int static_prio; 798 int normal_prio; 799 unsigned int rt_priority; 800 801 struct sched_entity se; 802 struct sched_rt_entity rt; 803 struct sched_dl_entity dl; 804 struct sched_dl_entity *dl_server; 805 const struct sched_class *sched_class; 806 807 #ifdef CONFIG_SCHED_CORE 808 struct rb_node core_node; 809 unsigned long core_cookie; 810 unsigned int core_occupation; 811 #endif 812 813 #ifdef CONFIG_CGROUP_SCHED 814 struct task_group *sched_task_group; 815 #endif 816 817 818 #ifdef CONFIG_UCLAMP_TASK 819 /* 820 * Clamp values requested for a scheduling entity. 821 * Must be updated with task_rq_lock() held. 822 */ 823 struct uclamp_se uclamp_req[UCLAMP_CNT]; 824 /* 825 * Effective clamp values used for a scheduling entity. 826 * Must be updated with task_rq_lock() held. 827 */ 828 struct uclamp_se uclamp[UCLAMP_CNT]; 829 #endif 830 831 struct sched_statistics stats; 832 833 #ifdef CONFIG_PREEMPT_NOTIFIERS 834 /* List of struct preempt_notifier: */ 835 struct hlist_head preempt_notifiers; 836 #endif 837 838 #ifdef CONFIG_BLK_DEV_IO_TRACE 839 unsigned int btrace_seq; 840 #endif 841 842 unsigned int policy; 843 unsigned long max_allowed_capacity; 844 int nr_cpus_allowed; 845 const cpumask_t *cpus_ptr; 846 cpumask_t *user_cpus_ptr; 847 cpumask_t cpus_mask; 848 void *migration_pending; 849 #ifdef CONFIG_SMP 850 unsigned short migration_disabled; 851 #endif 852 unsigned short migration_flags; 853 854 #ifdef CONFIG_PREEMPT_RCU 855 int rcu_read_lock_nesting; 856 union rcu_special rcu_read_unlock_special; 857 struct list_head rcu_node_entry; 858 struct rcu_node *rcu_blocked_node; 859 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 860 861 #ifdef CONFIG_TASKS_RCU 862 unsigned long rcu_tasks_nvcsw; 863 u8 rcu_tasks_holdout; 864 u8 rcu_tasks_idx; 865 int rcu_tasks_idle_cpu; 866 struct list_head rcu_tasks_holdout_list; 867 int rcu_tasks_exit_cpu; 868 struct list_head rcu_tasks_exit_list; 869 #endif /* #ifdef CONFIG_TASKS_RCU */ 870 871 #ifdef CONFIG_TASKS_TRACE_RCU 872 int trc_reader_nesting; 873 int trc_ipi_to_cpu; 874 union rcu_special trc_reader_special; 875 struct list_head trc_holdout_list; 876 struct list_head trc_blkd_node; 877 int trc_blkd_cpu; 878 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 879 880 struct sched_info sched_info; 881 882 struct list_head tasks; 883 #ifdef CONFIG_SMP 884 struct plist_node pushable_tasks; 885 struct rb_node pushable_dl_tasks; 886 #endif 887 888 struct mm_struct *mm; 889 struct mm_struct *active_mm; 890 struct address_space *faults_disabled_mapping; 891 892 int exit_state; 893 int exit_code; 894 int exit_signal; 895 /* The signal sent when the parent dies: */ 896 int pdeath_signal; 897 /* JOBCTL_*, siglock protected: */ 898 unsigned long jobctl; 899 900 /* Used for emulating ABI behavior of previous Linux versions: */ 901 unsigned int personality; 902 903 /* Scheduler bits, serialized by scheduler locks: */ 904 unsigned sched_reset_on_fork:1; 905 unsigned sched_contributes_to_load:1; 906 unsigned sched_migrated:1; 907 908 /* Force alignment to the next boundary: */ 909 unsigned :0; 910 911 /* Unserialized, strictly 'current' */ 912 913 /* 914 * This field must not be in the scheduler word above due to wakelist 915 * queueing no longer being serialized by p->on_cpu. However: 916 * 917 * p->XXX = X; ttwu() 918 * schedule() if (p->on_rq && ..) // false 919 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 920 * deactivate_task() ttwu_queue_wakelist()) 921 * p->on_rq = 0; p->sched_remote_wakeup = Y; 922 * 923 * guarantees all stores of 'current' are visible before 924 * ->sched_remote_wakeup gets used, so it can be in this word. 925 */ 926 unsigned sched_remote_wakeup:1; 927 #ifdef CONFIG_RT_MUTEXES 928 unsigned sched_rt_mutex:1; 929 #endif 930 931 /* Bit to tell TOMOYO we're in execve(): */ 932 unsigned in_execve:1; 933 unsigned in_iowait:1; 934 #ifndef TIF_RESTORE_SIGMASK 935 unsigned restore_sigmask:1; 936 #endif 937 #ifdef CONFIG_MEMCG 938 unsigned in_user_fault:1; 939 #endif 940 #ifdef CONFIG_LRU_GEN 941 /* whether the LRU algorithm may apply to this access */ 942 unsigned in_lru_fault:1; 943 #endif 944 #ifdef CONFIG_COMPAT_BRK 945 unsigned brk_randomized:1; 946 #endif 947 #ifdef CONFIG_CGROUPS 948 /* disallow userland-initiated cgroup migration */ 949 unsigned no_cgroup_migration:1; 950 /* task is frozen/stopped (used by the cgroup freezer) */ 951 unsigned frozen:1; 952 #endif 953 #ifdef CONFIG_BLK_CGROUP 954 unsigned use_memdelay:1; 955 #endif 956 #ifdef CONFIG_PSI 957 /* Stalled due to lack of memory */ 958 unsigned in_memstall:1; 959 #endif 960 #ifdef CONFIG_PAGE_OWNER 961 /* Used by page_owner=on to detect recursion in page tracking. */ 962 unsigned in_page_owner:1; 963 #endif 964 #ifdef CONFIG_EVENTFD 965 /* Recursion prevention for eventfd_signal() */ 966 unsigned in_eventfd:1; 967 #endif 968 #ifdef CONFIG_ARCH_HAS_CPU_PASID 969 unsigned pasid_activated:1; 970 #endif 971 #ifdef CONFIG_CPU_SUP_INTEL 972 unsigned reported_split_lock:1; 973 #endif 974 #ifdef CONFIG_TASK_DELAY_ACCT 975 /* delay due to memory thrashing */ 976 unsigned in_thrashing:1; 977 #endif 978 979 unsigned long atomic_flags; /* Flags requiring atomic access. */ 980 981 struct restart_block restart_block; 982 983 pid_t pid; 984 pid_t tgid; 985 986 #ifdef CONFIG_STACKPROTECTOR 987 /* Canary value for the -fstack-protector GCC feature: */ 988 unsigned long stack_canary; 989 #endif 990 /* 991 * Pointers to the (original) parent process, youngest child, younger sibling, 992 * older sibling, respectively. (p->father can be replaced with 993 * p->real_parent->pid) 994 */ 995 996 /* Real parent process: */ 997 struct task_struct __rcu *real_parent; 998 999 /* Recipient of SIGCHLD, wait4() reports: */ 1000 struct task_struct __rcu *parent; 1001 1002 /* 1003 * Children/sibling form the list of natural children: 1004 */ 1005 struct list_head children; 1006 struct list_head sibling; 1007 struct task_struct *group_leader; 1008 1009 /* 1010 * 'ptraced' is the list of tasks this task is using ptrace() on. 1011 * 1012 * This includes both natural children and PTRACE_ATTACH targets. 1013 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 1014 */ 1015 struct list_head ptraced; 1016 struct list_head ptrace_entry; 1017 1018 /* PID/PID hash table linkage. */ 1019 struct pid *thread_pid; 1020 struct hlist_node pid_links[PIDTYPE_MAX]; 1021 struct list_head thread_node; 1022 1023 struct completion *vfork_done; 1024 1025 /* CLONE_CHILD_SETTID: */ 1026 int __user *set_child_tid; 1027 1028 /* CLONE_CHILD_CLEARTID: */ 1029 int __user *clear_child_tid; 1030 1031 /* PF_KTHREAD | PF_IO_WORKER */ 1032 void *worker_private; 1033 1034 u64 utime; 1035 u64 stime; 1036 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1037 u64 utimescaled; 1038 u64 stimescaled; 1039 #endif 1040 u64 gtime; 1041 struct prev_cputime prev_cputime; 1042 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1043 struct vtime vtime; 1044 #endif 1045 1046 #ifdef CONFIG_NO_HZ_FULL 1047 atomic_t tick_dep_mask; 1048 #endif 1049 /* Context switch counts: */ 1050 unsigned long nvcsw; 1051 unsigned long nivcsw; 1052 1053 /* Monotonic time in nsecs: */ 1054 u64 start_time; 1055 1056 /* Boot based time in nsecs: */ 1057 u64 start_boottime; 1058 1059 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1060 unsigned long min_flt; 1061 unsigned long maj_flt; 1062 1063 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1064 struct posix_cputimers posix_cputimers; 1065 1066 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1067 struct posix_cputimers_work posix_cputimers_work; 1068 #endif 1069 1070 /* Process credentials: */ 1071 1072 /* Tracer's credentials at attach: */ 1073 const struct cred __rcu *ptracer_cred; 1074 1075 /* Objective and real subjective task credentials (COW): */ 1076 const struct cred __rcu *real_cred; 1077 1078 /* Effective (overridable) subjective task credentials (COW): */ 1079 const struct cred __rcu *cred; 1080 1081 #ifdef CONFIG_KEYS 1082 /* Cached requested key. */ 1083 struct key *cached_requested_key; 1084 #endif 1085 1086 /* 1087 * executable name, excluding path. 1088 * 1089 * - normally initialized setup_new_exec() 1090 * - access it with [gs]et_task_comm() 1091 * - lock it with task_lock() 1092 */ 1093 char comm[TASK_COMM_LEN]; 1094 1095 struct nameidata *nameidata; 1096 1097 #ifdef CONFIG_SYSVIPC 1098 struct sysv_sem sysvsem; 1099 struct sysv_shm sysvshm; 1100 #endif 1101 #ifdef CONFIG_DETECT_HUNG_TASK 1102 unsigned long last_switch_count; 1103 unsigned long last_switch_time; 1104 #endif 1105 /* Filesystem information: */ 1106 struct fs_struct *fs; 1107 1108 /* Open file information: */ 1109 struct files_struct *files; 1110 1111 #ifdef CONFIG_IO_URING 1112 struct io_uring_task *io_uring; 1113 #endif 1114 1115 /* Namespaces: */ 1116 struct nsproxy *nsproxy; 1117 1118 /* Signal handlers: */ 1119 struct signal_struct *signal; 1120 struct sighand_struct __rcu *sighand; 1121 sigset_t blocked; 1122 sigset_t real_blocked; 1123 /* Restored if set_restore_sigmask() was used: */ 1124 sigset_t saved_sigmask; 1125 struct sigpending pending; 1126 unsigned long sas_ss_sp; 1127 size_t sas_ss_size; 1128 unsigned int sas_ss_flags; 1129 1130 struct callback_head *task_works; 1131 1132 #ifdef CONFIG_AUDIT 1133 #ifdef CONFIG_AUDITSYSCALL 1134 struct audit_context *audit_context; 1135 #endif 1136 kuid_t loginuid; 1137 unsigned int sessionid; 1138 #endif 1139 struct seccomp seccomp; 1140 struct syscall_user_dispatch syscall_dispatch; 1141 1142 /* Thread group tracking: */ 1143 u64 parent_exec_id; 1144 u64 self_exec_id; 1145 1146 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1147 spinlock_t alloc_lock; 1148 1149 /* Protection of the PI data structures: */ 1150 raw_spinlock_t pi_lock; 1151 1152 struct wake_q_node wake_q; 1153 1154 #ifdef CONFIG_RT_MUTEXES 1155 /* PI waiters blocked on a rt_mutex held by this task: */ 1156 struct rb_root_cached pi_waiters; 1157 /* Updated under owner's pi_lock and rq lock */ 1158 struct task_struct *pi_top_task; 1159 /* Deadlock detection and priority inheritance handling: */ 1160 struct rt_mutex_waiter *pi_blocked_on; 1161 #endif 1162 1163 #ifdef CONFIG_DEBUG_MUTEXES 1164 /* Mutex deadlock detection: */ 1165 struct mutex_waiter *blocked_on; 1166 #endif 1167 1168 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1169 int non_block_count; 1170 #endif 1171 1172 #ifdef CONFIG_TRACE_IRQFLAGS 1173 struct irqtrace_events irqtrace; 1174 unsigned int hardirq_threaded; 1175 u64 hardirq_chain_key; 1176 int softirqs_enabled; 1177 int softirq_context; 1178 int irq_config; 1179 #endif 1180 #ifdef CONFIG_PREEMPT_RT 1181 int softirq_disable_cnt; 1182 #endif 1183 1184 #ifdef CONFIG_LOCKDEP 1185 # define MAX_LOCK_DEPTH 48UL 1186 u64 curr_chain_key; 1187 int lockdep_depth; 1188 unsigned int lockdep_recursion; 1189 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1190 #endif 1191 1192 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1193 unsigned int in_ubsan; 1194 #endif 1195 1196 /* Journalling filesystem info: */ 1197 void *journal_info; 1198 1199 /* Stacked block device info: */ 1200 struct bio_list *bio_list; 1201 1202 /* Stack plugging: */ 1203 struct blk_plug *plug; 1204 1205 /* VM state: */ 1206 struct reclaim_state *reclaim_state; 1207 1208 struct io_context *io_context; 1209 1210 #ifdef CONFIG_COMPACTION 1211 struct capture_control *capture_control; 1212 #endif 1213 /* Ptrace state: */ 1214 unsigned long ptrace_message; 1215 kernel_siginfo_t *last_siginfo; 1216 1217 struct task_io_accounting ioac; 1218 #ifdef CONFIG_PSI 1219 /* Pressure stall state */ 1220 unsigned int psi_flags; 1221 #endif 1222 #ifdef CONFIG_TASK_XACCT 1223 /* Accumulated RSS usage: */ 1224 u64 acct_rss_mem1; 1225 /* Accumulated virtual memory usage: */ 1226 u64 acct_vm_mem1; 1227 /* stime + utime since last update: */ 1228 u64 acct_timexpd; 1229 #endif 1230 #ifdef CONFIG_CPUSETS 1231 /* Protected by ->alloc_lock: */ 1232 nodemask_t mems_allowed; 1233 /* Sequence number to catch updates: */ 1234 seqcount_spinlock_t mems_allowed_seq; 1235 int cpuset_mem_spread_rotor; 1236 int cpuset_slab_spread_rotor; 1237 #endif 1238 #ifdef CONFIG_CGROUPS 1239 /* Control Group info protected by css_set_lock: */ 1240 struct css_set __rcu *cgroups; 1241 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1242 struct list_head cg_list; 1243 #endif 1244 #ifdef CONFIG_X86_CPU_RESCTRL 1245 u32 closid; 1246 u32 rmid; 1247 #endif 1248 #ifdef CONFIG_FUTEX 1249 struct robust_list_head __user *robust_list; 1250 #ifdef CONFIG_COMPAT 1251 struct compat_robust_list_head __user *compat_robust_list; 1252 #endif 1253 struct list_head pi_state_list; 1254 struct futex_pi_state *pi_state_cache; 1255 struct mutex futex_exit_mutex; 1256 unsigned int futex_state; 1257 #endif 1258 #ifdef CONFIG_PERF_EVENTS 1259 struct perf_event_context *perf_event_ctxp; 1260 struct mutex perf_event_mutex; 1261 struct list_head perf_event_list; 1262 #endif 1263 #ifdef CONFIG_DEBUG_PREEMPT 1264 unsigned long preempt_disable_ip; 1265 #endif 1266 #ifdef CONFIG_NUMA 1267 /* Protected by alloc_lock: */ 1268 struct mempolicy *mempolicy; 1269 short il_prev; 1270 u8 il_weight; 1271 short pref_node_fork; 1272 #endif 1273 #ifdef CONFIG_NUMA_BALANCING 1274 int numa_scan_seq; 1275 unsigned int numa_scan_period; 1276 unsigned int numa_scan_period_max; 1277 int numa_preferred_nid; 1278 unsigned long numa_migrate_retry; 1279 /* Migration stamp: */ 1280 u64 node_stamp; 1281 u64 last_task_numa_placement; 1282 u64 last_sum_exec_runtime; 1283 struct callback_head numa_work; 1284 1285 /* 1286 * This pointer is only modified for current in syscall and 1287 * pagefault context (and for tasks being destroyed), so it can be read 1288 * from any of the following contexts: 1289 * - RCU read-side critical section 1290 * - current->numa_group from everywhere 1291 * - task's runqueue locked, task not running 1292 */ 1293 struct numa_group __rcu *numa_group; 1294 1295 /* 1296 * numa_faults is an array split into four regions: 1297 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1298 * in this precise order. 1299 * 1300 * faults_memory: Exponential decaying average of faults on a per-node 1301 * basis. Scheduling placement decisions are made based on these 1302 * counts. The values remain static for the duration of a PTE scan. 1303 * faults_cpu: Track the nodes the process was running on when a NUMA 1304 * hinting fault was incurred. 1305 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1306 * during the current scan window. When the scan completes, the counts 1307 * in faults_memory and faults_cpu decay and these values are copied. 1308 */ 1309 unsigned long *numa_faults; 1310 unsigned long total_numa_faults; 1311 1312 /* 1313 * numa_faults_locality tracks if faults recorded during the last 1314 * scan window were remote/local or failed to migrate. The task scan 1315 * period is adapted based on the locality of the faults with different 1316 * weights depending on whether they were shared or private faults 1317 */ 1318 unsigned long numa_faults_locality[3]; 1319 1320 unsigned long numa_pages_migrated; 1321 #endif /* CONFIG_NUMA_BALANCING */ 1322 1323 #ifdef CONFIG_RSEQ 1324 struct rseq __user *rseq; 1325 u32 rseq_len; 1326 u32 rseq_sig; 1327 /* 1328 * RmW on rseq_event_mask must be performed atomically 1329 * with respect to preemption. 1330 */ 1331 unsigned long rseq_event_mask; 1332 #endif 1333 1334 #ifdef CONFIG_SCHED_MM_CID 1335 int mm_cid; /* Current cid in mm */ 1336 int last_mm_cid; /* Most recent cid in mm */ 1337 int migrate_from_cpu; 1338 int mm_cid_active; /* Whether cid bitmap is active */ 1339 struct callback_head cid_work; 1340 #endif 1341 1342 struct tlbflush_unmap_batch tlb_ubc; 1343 1344 /* Cache last used pipe for splice(): */ 1345 struct pipe_inode_info *splice_pipe; 1346 1347 struct page_frag task_frag; 1348 1349 #ifdef CONFIG_TASK_DELAY_ACCT 1350 struct task_delay_info *delays; 1351 #endif 1352 1353 #ifdef CONFIG_FAULT_INJECTION 1354 int make_it_fail; 1355 unsigned int fail_nth; 1356 #endif 1357 /* 1358 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1359 * balance_dirty_pages() for a dirty throttling pause: 1360 */ 1361 int nr_dirtied; 1362 int nr_dirtied_pause; 1363 /* Start of a write-and-pause period: */ 1364 unsigned long dirty_paused_when; 1365 1366 #ifdef CONFIG_LATENCYTOP 1367 int latency_record_count; 1368 struct latency_record latency_record[LT_SAVECOUNT]; 1369 #endif 1370 /* 1371 * Time slack values; these are used to round up poll() and 1372 * select() etc timeout values. These are in nanoseconds. 1373 */ 1374 u64 timer_slack_ns; 1375 u64 default_timer_slack_ns; 1376 1377 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1378 unsigned int kasan_depth; 1379 #endif 1380 1381 #ifdef CONFIG_KCSAN 1382 struct kcsan_ctx kcsan_ctx; 1383 #ifdef CONFIG_TRACE_IRQFLAGS 1384 struct irqtrace_events kcsan_save_irqtrace; 1385 #endif 1386 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1387 int kcsan_stack_depth; 1388 #endif 1389 #endif 1390 1391 #ifdef CONFIG_KMSAN 1392 struct kmsan_ctx kmsan_ctx; 1393 #endif 1394 1395 #if IS_ENABLED(CONFIG_KUNIT) 1396 struct kunit *kunit_test; 1397 #endif 1398 1399 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1400 /* Index of current stored address in ret_stack: */ 1401 int curr_ret_stack; 1402 int curr_ret_depth; 1403 1404 /* Stack of return addresses for return function tracing: */ 1405 struct ftrace_ret_stack *ret_stack; 1406 1407 /* Timestamp for last schedule: */ 1408 unsigned long long ftrace_timestamp; 1409 1410 /* 1411 * Number of functions that haven't been traced 1412 * because of depth overrun: 1413 */ 1414 atomic_t trace_overrun; 1415 1416 /* Pause tracing: */ 1417 atomic_t tracing_graph_pause; 1418 #endif 1419 1420 #ifdef CONFIG_TRACING 1421 /* Bitmask and counter of trace recursion: */ 1422 unsigned long trace_recursion; 1423 #endif /* CONFIG_TRACING */ 1424 1425 #ifdef CONFIG_KCOV 1426 /* See kernel/kcov.c for more details. */ 1427 1428 /* Coverage collection mode enabled for this task (0 if disabled): */ 1429 unsigned int kcov_mode; 1430 1431 /* Size of the kcov_area: */ 1432 unsigned int kcov_size; 1433 1434 /* Buffer for coverage collection: */ 1435 void *kcov_area; 1436 1437 /* KCOV descriptor wired with this task or NULL: */ 1438 struct kcov *kcov; 1439 1440 /* KCOV common handle for remote coverage collection: */ 1441 u64 kcov_handle; 1442 1443 /* KCOV sequence number: */ 1444 int kcov_sequence; 1445 1446 /* Collect coverage from softirq context: */ 1447 unsigned int kcov_softirq; 1448 #endif 1449 1450 #ifdef CONFIG_MEMCG 1451 struct mem_cgroup *memcg_in_oom; 1452 1453 /* Number of pages to reclaim on returning to userland: */ 1454 unsigned int memcg_nr_pages_over_high; 1455 1456 /* Used by memcontrol for targeted memcg charge: */ 1457 struct mem_cgroup *active_memcg; 1458 #endif 1459 1460 #ifdef CONFIG_MEMCG_KMEM 1461 struct obj_cgroup *objcg; 1462 #endif 1463 1464 #ifdef CONFIG_BLK_CGROUP 1465 struct gendisk *throttle_disk; 1466 #endif 1467 1468 #ifdef CONFIG_UPROBES 1469 struct uprobe_task *utask; 1470 #endif 1471 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1472 unsigned int sequential_io; 1473 unsigned int sequential_io_avg; 1474 #endif 1475 struct kmap_ctrl kmap_ctrl; 1476 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1477 unsigned long task_state_change; 1478 # ifdef CONFIG_PREEMPT_RT 1479 unsigned long saved_state_change; 1480 # endif 1481 #endif 1482 struct rcu_head rcu; 1483 refcount_t rcu_users; 1484 int pagefault_disabled; 1485 #ifdef CONFIG_MMU 1486 struct task_struct *oom_reaper_list; 1487 struct timer_list oom_reaper_timer; 1488 #endif 1489 #ifdef CONFIG_VMAP_STACK 1490 struct vm_struct *stack_vm_area; 1491 #endif 1492 #ifdef CONFIG_THREAD_INFO_IN_TASK 1493 /* A live task holds one reference: */ 1494 refcount_t stack_refcount; 1495 #endif 1496 #ifdef CONFIG_LIVEPATCH 1497 int patch_state; 1498 #endif 1499 #ifdef CONFIG_SECURITY 1500 /* Used by LSM modules for access restriction: */ 1501 void *security; 1502 #endif 1503 #ifdef CONFIG_BPF_SYSCALL 1504 /* Used by BPF task local storage */ 1505 struct bpf_local_storage __rcu *bpf_storage; 1506 /* Used for BPF run context */ 1507 struct bpf_run_ctx *bpf_ctx; 1508 #endif 1509 1510 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1511 unsigned long lowest_stack; 1512 unsigned long prev_lowest_stack; 1513 #endif 1514 1515 #ifdef CONFIG_X86_MCE 1516 void __user *mce_vaddr; 1517 __u64 mce_kflags; 1518 u64 mce_addr; 1519 __u64 mce_ripv : 1, 1520 mce_whole_page : 1, 1521 __mce_reserved : 62; 1522 struct callback_head mce_kill_me; 1523 int mce_count; 1524 #endif 1525 1526 #ifdef CONFIG_KRETPROBES 1527 struct llist_head kretprobe_instances; 1528 #endif 1529 #ifdef CONFIG_RETHOOK 1530 struct llist_head rethooks; 1531 #endif 1532 1533 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1534 /* 1535 * If L1D flush is supported on mm context switch 1536 * then we use this callback head to queue kill work 1537 * to kill tasks that are not running on SMT disabled 1538 * cores 1539 */ 1540 struct callback_head l1d_flush_kill; 1541 #endif 1542 1543 #ifdef CONFIG_RV 1544 /* 1545 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1546 * If we find justification for more monitors, we can think 1547 * about adding more or developing a dynamic method. So far, 1548 * none of these are justified. 1549 */ 1550 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1551 #endif 1552 1553 #ifdef CONFIG_USER_EVENTS 1554 struct user_event_mm *user_event_mm; 1555 #endif 1556 1557 /* 1558 * New fields for task_struct should be added above here, so that 1559 * they are included in the randomized portion of task_struct. 1560 */ 1561 randomized_struct_fields_end 1562 1563 /* CPU-specific state of this task: */ 1564 struct thread_struct thread; 1565 1566 /* 1567 * WARNING: on x86, 'thread_struct' contains a variable-sized 1568 * structure. It *MUST* be at the end of 'task_struct'. 1569 * 1570 * Do not put anything below here! 1571 */ 1572 }; 1573 1574 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1575 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1576 1577 static inline unsigned int __task_state_index(unsigned int tsk_state, 1578 unsigned int tsk_exit_state) 1579 { 1580 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1581 1582 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1583 1584 if ((tsk_state & TASK_IDLE) == TASK_IDLE) 1585 state = TASK_REPORT_IDLE; 1586 1587 /* 1588 * We're lying here, but rather than expose a completely new task state 1589 * to userspace, we can make this appear as if the task has gone through 1590 * a regular rt_mutex_lock() call. 1591 */ 1592 if (tsk_state & TASK_RTLOCK_WAIT) 1593 state = TASK_UNINTERRUPTIBLE; 1594 1595 return fls(state); 1596 } 1597 1598 static inline unsigned int task_state_index(struct task_struct *tsk) 1599 { 1600 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1601 } 1602 1603 static inline char task_index_to_char(unsigned int state) 1604 { 1605 static const char state_char[] = "RSDTtXZPI"; 1606 1607 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1608 1609 return state_char[state]; 1610 } 1611 1612 static inline char task_state_to_char(struct task_struct *tsk) 1613 { 1614 return task_index_to_char(task_state_index(tsk)); 1615 } 1616 1617 extern struct pid *cad_pid; 1618 1619 /* 1620 * Per process flags 1621 */ 1622 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1623 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1624 #define PF_EXITING 0x00000004 /* Getting shut down */ 1625 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1626 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1627 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1628 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1629 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1630 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1631 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1632 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1633 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */ 1634 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1635 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1636 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1637 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1638 #define PF__HOLE__00010000 0x00010000 1639 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1640 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */ 1641 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */ 1642 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1643 * I am cleaning dirty pages from some other bdi. */ 1644 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1645 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1646 #define PF_MEMALLOC_NORECLAIM 0x00800000 /* All allocation requests will clear __GFP_DIRECT_RECLAIM */ 1647 #define PF_MEMALLOC_NOWARN 0x01000000 /* All allocation requests will inherit __GFP_NOWARN */ 1648 #define PF__HOLE__02000000 0x02000000 1649 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1650 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1651 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning. 1652 * See memalloc_pin_save() */ 1653 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */ 1654 #define PF__HOLE__40000000 0x40000000 1655 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1656 1657 /* 1658 * Only the _current_ task can read/write to tsk->flags, but other 1659 * tasks can access tsk->flags in readonly mode for example 1660 * with tsk_used_math (like during threaded core dumping). 1661 * There is however an exception to this rule during ptrace 1662 * or during fork: the ptracer task is allowed to write to the 1663 * child->flags of its traced child (same goes for fork, the parent 1664 * can write to the child->flags), because we're guaranteed the 1665 * child is not running and in turn not changing child->flags 1666 * at the same time the parent does it. 1667 */ 1668 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1669 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1670 #define clear_used_math() clear_stopped_child_used_math(current) 1671 #define set_used_math() set_stopped_child_used_math(current) 1672 1673 #define conditional_stopped_child_used_math(condition, child) \ 1674 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1675 1676 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1677 1678 #define copy_to_stopped_child_used_math(child) \ 1679 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1680 1681 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1682 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1683 #define used_math() tsk_used_math(current) 1684 1685 static __always_inline bool is_percpu_thread(void) 1686 { 1687 #ifdef CONFIG_SMP 1688 return (current->flags & PF_NO_SETAFFINITY) && 1689 (current->nr_cpus_allowed == 1); 1690 #else 1691 return true; 1692 #endif 1693 } 1694 1695 /* Per-process atomic flags. */ 1696 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1697 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1698 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1699 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1700 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1701 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1702 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1703 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1704 1705 #define TASK_PFA_TEST(name, func) \ 1706 static inline bool task_##func(struct task_struct *p) \ 1707 { return test_bit(PFA_##name, &p->atomic_flags); } 1708 1709 #define TASK_PFA_SET(name, func) \ 1710 static inline void task_set_##func(struct task_struct *p) \ 1711 { set_bit(PFA_##name, &p->atomic_flags); } 1712 1713 #define TASK_PFA_CLEAR(name, func) \ 1714 static inline void task_clear_##func(struct task_struct *p) \ 1715 { clear_bit(PFA_##name, &p->atomic_flags); } 1716 1717 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1718 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1719 1720 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1721 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1722 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1723 1724 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1725 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1726 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1727 1728 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1729 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1730 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1731 1732 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1733 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1734 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1735 1736 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1737 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1738 1739 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1740 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1741 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1742 1743 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1744 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1745 1746 static inline void 1747 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1748 { 1749 current->flags &= ~flags; 1750 current->flags |= orig_flags & flags; 1751 } 1752 1753 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1754 extern int task_can_attach(struct task_struct *p); 1755 extern int dl_bw_alloc(int cpu, u64 dl_bw); 1756 extern void dl_bw_free(int cpu, u64 dl_bw); 1757 #ifdef CONFIG_SMP 1758 1759 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */ 1760 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1761 1762 /** 1763 * set_cpus_allowed_ptr - set CPU affinity mask of a task 1764 * @p: the task 1765 * @new_mask: CPU affinity mask 1766 * 1767 * Return: zero if successful, or a negative error code 1768 */ 1769 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1770 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1771 extern void release_user_cpus_ptr(struct task_struct *p); 1772 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1773 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1774 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1775 #else 1776 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1777 { 1778 } 1779 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1780 { 1781 if (!cpumask_test_cpu(0, new_mask)) 1782 return -EINVAL; 1783 return 0; 1784 } 1785 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1786 { 1787 if (src->user_cpus_ptr) 1788 return -EINVAL; 1789 return 0; 1790 } 1791 static inline void release_user_cpus_ptr(struct task_struct *p) 1792 { 1793 WARN_ON(p->user_cpus_ptr); 1794 } 1795 1796 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1797 { 1798 return 0; 1799 } 1800 #endif 1801 1802 extern int yield_to(struct task_struct *p, bool preempt); 1803 extern void set_user_nice(struct task_struct *p, long nice); 1804 extern int task_prio(const struct task_struct *p); 1805 1806 /** 1807 * task_nice - return the nice value of a given task. 1808 * @p: the task in question. 1809 * 1810 * Return: The nice value [ -20 ... 0 ... 19 ]. 1811 */ 1812 static inline int task_nice(const struct task_struct *p) 1813 { 1814 return PRIO_TO_NICE((p)->static_prio); 1815 } 1816 1817 extern int can_nice(const struct task_struct *p, const int nice); 1818 extern int task_curr(const struct task_struct *p); 1819 extern int idle_cpu(int cpu); 1820 extern int available_idle_cpu(int cpu); 1821 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1822 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1823 extern void sched_set_fifo(struct task_struct *p); 1824 extern void sched_set_fifo_low(struct task_struct *p); 1825 extern void sched_set_normal(struct task_struct *p, int nice); 1826 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1827 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1828 extern struct task_struct *idle_task(int cpu); 1829 1830 /** 1831 * is_idle_task - is the specified task an idle task? 1832 * @p: the task in question. 1833 * 1834 * Return: 1 if @p is an idle task. 0 otherwise. 1835 */ 1836 static __always_inline bool is_idle_task(const struct task_struct *p) 1837 { 1838 return !!(p->flags & PF_IDLE); 1839 } 1840 1841 extern struct task_struct *curr_task(int cpu); 1842 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1843 1844 void yield(void); 1845 1846 union thread_union { 1847 struct task_struct task; 1848 #ifndef CONFIG_THREAD_INFO_IN_TASK 1849 struct thread_info thread_info; 1850 #endif 1851 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1852 }; 1853 1854 #ifndef CONFIG_THREAD_INFO_IN_TASK 1855 extern struct thread_info init_thread_info; 1856 #endif 1857 1858 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1859 1860 #ifdef CONFIG_THREAD_INFO_IN_TASK 1861 # define task_thread_info(task) (&(task)->thread_info) 1862 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1863 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1864 #endif 1865 1866 /* 1867 * find a task by one of its numerical ids 1868 * 1869 * find_task_by_pid_ns(): 1870 * finds a task by its pid in the specified namespace 1871 * find_task_by_vpid(): 1872 * finds a task by its virtual pid 1873 * 1874 * see also find_vpid() etc in include/linux/pid.h 1875 */ 1876 1877 extern struct task_struct *find_task_by_vpid(pid_t nr); 1878 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1879 1880 /* 1881 * find a task by its virtual pid and get the task struct 1882 */ 1883 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1884 1885 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1886 extern int wake_up_process(struct task_struct *tsk); 1887 extern void wake_up_new_task(struct task_struct *tsk); 1888 1889 #ifdef CONFIG_SMP 1890 extern void kick_process(struct task_struct *tsk); 1891 #else 1892 static inline void kick_process(struct task_struct *tsk) { } 1893 #endif 1894 1895 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1896 1897 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1898 { 1899 __set_task_comm(tsk, from, false); 1900 } 1901 1902 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1903 #define get_task_comm(buf, tsk) ({ \ 1904 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1905 __get_task_comm(buf, sizeof(buf), tsk); \ 1906 }) 1907 1908 #ifdef CONFIG_SMP 1909 static __always_inline void scheduler_ipi(void) 1910 { 1911 /* 1912 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1913 * TIF_NEED_RESCHED remotely (for the first time) will also send 1914 * this IPI. 1915 */ 1916 preempt_fold_need_resched(); 1917 } 1918 #else 1919 static inline void scheduler_ipi(void) { } 1920 #endif 1921 1922 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1923 1924 /* 1925 * Set thread flags in other task's structures. 1926 * See asm/thread_info.h for TIF_xxxx flags available: 1927 */ 1928 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1929 { 1930 set_ti_thread_flag(task_thread_info(tsk), flag); 1931 } 1932 1933 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1934 { 1935 clear_ti_thread_flag(task_thread_info(tsk), flag); 1936 } 1937 1938 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 1939 bool value) 1940 { 1941 update_ti_thread_flag(task_thread_info(tsk), flag, value); 1942 } 1943 1944 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1945 { 1946 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1947 } 1948 1949 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1950 { 1951 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1952 } 1953 1954 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1955 { 1956 return test_ti_thread_flag(task_thread_info(tsk), flag); 1957 } 1958 1959 static inline void set_tsk_need_resched(struct task_struct *tsk) 1960 { 1961 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1962 } 1963 1964 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1965 { 1966 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1967 } 1968 1969 static inline int test_tsk_need_resched(struct task_struct *tsk) 1970 { 1971 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 1972 } 1973 1974 /* 1975 * cond_resched() and cond_resched_lock(): latency reduction via 1976 * explicit rescheduling in places that are safe. The return 1977 * value indicates whether a reschedule was done in fact. 1978 * cond_resched_lock() will drop the spinlock before scheduling, 1979 */ 1980 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 1981 extern int __cond_resched(void); 1982 1983 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 1984 1985 void sched_dynamic_klp_enable(void); 1986 void sched_dynamic_klp_disable(void); 1987 1988 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 1989 1990 static __always_inline int _cond_resched(void) 1991 { 1992 return static_call_mod(cond_resched)(); 1993 } 1994 1995 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 1996 1997 extern int dynamic_cond_resched(void); 1998 1999 static __always_inline int _cond_resched(void) 2000 { 2001 return dynamic_cond_resched(); 2002 } 2003 2004 #else /* !CONFIG_PREEMPTION */ 2005 2006 static inline int _cond_resched(void) 2007 { 2008 klp_sched_try_switch(); 2009 return __cond_resched(); 2010 } 2011 2012 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2013 2014 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2015 2016 static inline int _cond_resched(void) 2017 { 2018 klp_sched_try_switch(); 2019 return 0; 2020 } 2021 2022 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2023 2024 #define cond_resched() ({ \ 2025 __might_resched(__FILE__, __LINE__, 0); \ 2026 _cond_resched(); \ 2027 }) 2028 2029 extern int __cond_resched_lock(spinlock_t *lock); 2030 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2031 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2032 2033 #define MIGHT_RESCHED_RCU_SHIFT 8 2034 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2035 2036 #ifndef CONFIG_PREEMPT_RT 2037 /* 2038 * Non RT kernels have an elevated preempt count due to the held lock, 2039 * but are not allowed to be inside a RCU read side critical section 2040 */ 2041 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2042 #else 2043 /* 2044 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2045 * cond_resched*lock() has to take that into account because it checks for 2046 * preempt_count() and rcu_preempt_depth(). 2047 */ 2048 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2049 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2050 #endif 2051 2052 #define cond_resched_lock(lock) ({ \ 2053 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2054 __cond_resched_lock(lock); \ 2055 }) 2056 2057 #define cond_resched_rwlock_read(lock) ({ \ 2058 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2059 __cond_resched_rwlock_read(lock); \ 2060 }) 2061 2062 #define cond_resched_rwlock_write(lock) ({ \ 2063 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2064 __cond_resched_rwlock_write(lock); \ 2065 }) 2066 2067 #ifdef CONFIG_PREEMPT_DYNAMIC 2068 2069 extern bool preempt_model_none(void); 2070 extern bool preempt_model_voluntary(void); 2071 extern bool preempt_model_full(void); 2072 2073 #else 2074 2075 static inline bool preempt_model_none(void) 2076 { 2077 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2078 } 2079 static inline bool preempt_model_voluntary(void) 2080 { 2081 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2082 } 2083 static inline bool preempt_model_full(void) 2084 { 2085 return IS_ENABLED(CONFIG_PREEMPT); 2086 } 2087 2088 #endif 2089 2090 static inline bool preempt_model_rt(void) 2091 { 2092 return IS_ENABLED(CONFIG_PREEMPT_RT); 2093 } 2094 2095 /* 2096 * Does the preemption model allow non-cooperative preemption? 2097 * 2098 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2099 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2100 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2101 * PREEMPT_NONE model. 2102 */ 2103 static inline bool preempt_model_preemptible(void) 2104 { 2105 return preempt_model_full() || preempt_model_rt(); 2106 } 2107 2108 static __always_inline bool need_resched(void) 2109 { 2110 return unlikely(tif_need_resched()); 2111 } 2112 2113 /* 2114 * Wrappers for p->thread_info->cpu access. No-op on UP. 2115 */ 2116 #ifdef CONFIG_SMP 2117 2118 static inline unsigned int task_cpu(const struct task_struct *p) 2119 { 2120 return READ_ONCE(task_thread_info(p)->cpu); 2121 } 2122 2123 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2124 2125 #else 2126 2127 static inline unsigned int task_cpu(const struct task_struct *p) 2128 { 2129 return 0; 2130 } 2131 2132 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2133 { 2134 } 2135 2136 #endif /* CONFIG_SMP */ 2137 2138 extern bool sched_task_on_rq(struct task_struct *p); 2139 extern unsigned long get_wchan(struct task_struct *p); 2140 extern struct task_struct *cpu_curr_snapshot(int cpu); 2141 2142 #include <linux/spinlock.h> 2143 2144 /* 2145 * In order to reduce various lock holder preemption latencies provide an 2146 * interface to see if a vCPU is currently running or not. 2147 * 2148 * This allows us to terminate optimistic spin loops and block, analogous to 2149 * the native optimistic spin heuristic of testing if the lock owner task is 2150 * running or not. 2151 */ 2152 #ifndef vcpu_is_preempted 2153 static inline bool vcpu_is_preempted(int cpu) 2154 { 2155 return false; 2156 } 2157 #endif 2158 2159 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2160 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2161 2162 #ifndef TASK_SIZE_OF 2163 #define TASK_SIZE_OF(tsk) TASK_SIZE 2164 #endif 2165 2166 #ifdef CONFIG_SMP 2167 static inline bool owner_on_cpu(struct task_struct *owner) 2168 { 2169 /* 2170 * As lock holder preemption issue, we both skip spinning if 2171 * task is not on cpu or its cpu is preempted 2172 */ 2173 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2174 } 2175 2176 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2177 unsigned long sched_cpu_util(int cpu); 2178 #endif /* CONFIG_SMP */ 2179 2180 #ifdef CONFIG_SCHED_CORE 2181 extern void sched_core_free(struct task_struct *tsk); 2182 extern void sched_core_fork(struct task_struct *p); 2183 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2184 unsigned long uaddr); 2185 extern int sched_core_idle_cpu(int cpu); 2186 #else 2187 static inline void sched_core_free(struct task_struct *tsk) { } 2188 static inline void sched_core_fork(struct task_struct *p) { } 2189 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); } 2190 #endif 2191 2192 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2193 2194 #ifdef CONFIG_MEM_ALLOC_PROFILING 2195 static inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag) 2196 { 2197 swap(current->alloc_tag, tag); 2198 return tag; 2199 } 2200 2201 static inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old) 2202 { 2203 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 2204 WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n"); 2205 #endif 2206 current->alloc_tag = old; 2207 } 2208 #else 2209 #define alloc_tag_save(_tag) NULL 2210 #define alloc_tag_restore(_tag, _old) do {} while (0) 2211 #endif 2212 2213 #endif 2214