1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SCHED_H 3 #define _LINUX_SCHED_H 4 5 /* 6 * Define 'struct task_struct' and provide the main scheduler 7 * APIs (schedule(), wakeup variants, etc.) 8 */ 9 10 #include <uapi/linux/sched.h> 11 12 #include <asm/current.h> 13 #include <asm/processor.h> 14 #include <linux/thread_info.h> 15 #include <linux/preempt.h> 16 #include <linux/cpumask_types.h> 17 18 #include <linux/cache.h> 19 #include <linux/futex_types.h> 20 #include <linux/irqflags_types.h> 21 #include <linux/smp_types.h> 22 #include <linux/pid_types.h> 23 #include <linux/sem_types.h> 24 #include <linux/shm.h> 25 #include <linux/kmsan_types.h> 26 #include <linux/mutex_types.h> 27 #include <linux/plist_types.h> 28 #include <linux/hrtimer_types.h> 29 #include <linux/timer_types.h> 30 #include <linux/seccomp_types.h> 31 #include <linux/nodemask_types.h> 32 #include <linux/refcount_types.h> 33 #include <linux/resource.h> 34 #include <linux/latencytop.h> 35 #include <linux/sched/prio.h> 36 #include <linux/sched/types.h> 37 #include <linux/signal_types.h> 38 #include <linux/spinlock.h> 39 #include <linux/syscall_user_dispatch_types.h> 40 #include <linux/mm_types_task.h> 41 #include <linux/netdevice_xmit.h> 42 #include <linux/task_io_accounting.h> 43 #include <linux/posix-timers_types.h> 44 #include <linux/restart_block.h> 45 #include <linux/rseq_types.h> 46 #include <linux/seqlock_types.h> 47 #include <linux/kcsan.h> 48 #include <linux/rv.h> 49 #include <linux/uidgid_types.h> 50 #include <linux/tracepoint-defs.h> 51 #include <linux/unwind_deferred_types.h> 52 #include <asm/kmap_size.h> 53 #include <linux/time64.h> 54 #ifndef COMPILE_OFFSETS 55 #include <generated/rq-offsets.h> 56 #endif 57 58 /* task_struct member predeclarations (sorted alphabetically): */ 59 struct audit_context; 60 struct bio_list; 61 struct blk_plug; 62 struct bpf_local_storage; 63 struct bpf_run_ctx; 64 struct bpf_net_context; 65 struct capture_control; 66 struct cfs_rq; 67 struct fs_struct; 68 struct io_context; 69 struct io_uring_task; 70 struct mempolicy; 71 struct nameidata; 72 struct nsproxy; 73 struct perf_event_context; 74 struct perf_ctx_data; 75 struct pid_namespace; 76 struct pipe_inode_info; 77 struct rcu_node; 78 struct reclaim_state; 79 struct root_domain; 80 struct rq; 81 struct sched_attr; 82 struct sched_dl_entity; 83 struct seq_file; 84 struct sighand_struct; 85 struct signal_struct; 86 struct task_delay_info; 87 struct task_exec_state; 88 struct task_group; 89 struct task_struct; 90 struct timespec64; 91 struct user_event_mm; 92 93 #include <linux/sched/ext.h> 94 95 /* 96 * Task state bitmask. NOTE! These bits are also 97 * encoded in fs/proc/array.c: get_task_state(). 98 * 99 * We have two separate sets of flags: task->__state 100 * is about runnability, while task->exit_state are 101 * about the task exiting. Confusing, but this way 102 * modifying one set can't modify the other one by 103 * mistake. 104 */ 105 106 /* Used in tsk->__state: */ 107 #define TASK_RUNNING 0x00000000 108 #define TASK_INTERRUPTIBLE 0x00000001 109 #define TASK_UNINTERRUPTIBLE 0x00000002 110 #define __TASK_STOPPED 0x00000004 111 #define __TASK_TRACED 0x00000008 112 /* Used in tsk->exit_state: */ 113 #define EXIT_DEAD 0x00000010 114 #define EXIT_ZOMBIE 0x00000020 115 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 116 /* Used in tsk->__state again: */ 117 #define TASK_PARKED 0x00000040 118 #define TASK_DEAD 0x00000080 119 #define TASK_WAKEKILL 0x00000100 120 #define TASK_WAKING 0x00000200 121 #define TASK_NOLOAD 0x00000400 122 #define TASK_NEW 0x00000800 123 #define TASK_RTLOCK_WAIT 0x00001000 124 #define TASK_FREEZABLE 0x00002000 125 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 126 #define TASK_FROZEN 0x00008000 127 #define TASK_STATE_MAX 0x00010000 128 129 #define TASK_ANY (TASK_STATE_MAX-1) 130 131 /* 132 * DO NOT ADD ANY NEW USERS ! 133 */ 134 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 135 136 /* Convenience macros for the sake of set_current_state: */ 137 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 138 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 139 #define TASK_TRACED __TASK_TRACED 140 141 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 142 143 /* Convenience macros for the sake of wake_up(): */ 144 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 145 146 /* get_task_state(): */ 147 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 148 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 149 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 150 TASK_PARKED) 151 152 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 153 154 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 155 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 156 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 157 158 /* 159 * Special states are those that do not use the normal wait-loop pattern. See 160 * the comment with set_special_state(). 161 */ 162 #define is_special_task_state(state) \ 163 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | \ 164 TASK_DEAD | TASK_WAKING | TASK_FROZEN)) 165 166 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 167 # define debug_normal_state_change(state_value) \ 168 do { \ 169 WARN_ON_ONCE(is_special_task_state(state_value)); \ 170 current->task_state_change = _THIS_IP_; \ 171 } while (0) 172 173 # define debug_special_state_change(state_value) \ 174 do { \ 175 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 176 current->task_state_change = _THIS_IP_; \ 177 } while (0) 178 179 # define debug_rtlock_wait_set_state() \ 180 do { \ 181 current->saved_state_change = current->task_state_change;\ 182 current->task_state_change = _THIS_IP_; \ 183 } while (0) 184 185 # define debug_rtlock_wait_restore_state() \ 186 do { \ 187 current->task_state_change = current->saved_state_change;\ 188 } while (0) 189 190 #else 191 # define debug_normal_state_change(cond) do { } while (0) 192 # define debug_special_state_change(cond) do { } while (0) 193 # define debug_rtlock_wait_set_state() do { } while (0) 194 # define debug_rtlock_wait_restore_state() do { } while (0) 195 #endif 196 197 #define trace_set_current_state(state_value) \ 198 do { \ 199 if (tracepoint_enabled(sched_set_state_tp)) \ 200 __trace_set_current_state(state_value); \ 201 } while (0) 202 203 /* 204 * set_current_state() includes a barrier so that the write of current->__state 205 * is correctly serialised wrt the caller's subsequent test of whether to 206 * actually sleep: 207 * 208 * for (;;) { 209 * set_current_state(TASK_UNINTERRUPTIBLE); 210 * if (CONDITION) 211 * break; 212 * 213 * schedule(); 214 * } 215 * __set_current_state(TASK_RUNNING); 216 * 217 * If the caller does not need such serialisation (because, for instance, the 218 * CONDITION test and condition change and wakeup are under the same lock) then 219 * use __set_current_state(). 220 * 221 * The above is typically ordered against the wakeup, which does: 222 * 223 * CONDITION = 1; 224 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 225 * 226 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 227 * accessing p->__state. 228 * 229 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is, 230 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 231 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 232 * 233 * However, with slightly different timing the wakeup TASK_RUNNING store can 234 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 235 * a problem either because that will result in one extra go around the loop 236 * and our @cond test will save the day. 237 * 238 * Also see the comments of try_to_wake_up(). 239 */ 240 #define __set_current_state(state_value) \ 241 do { \ 242 debug_normal_state_change((state_value)); \ 243 trace_set_current_state(state_value); \ 244 WRITE_ONCE(current->__state, (state_value)); \ 245 } while (0) 246 247 #define set_current_state(state_value) \ 248 do { \ 249 debug_normal_state_change((state_value)); \ 250 trace_set_current_state(state_value); \ 251 smp_store_mb(current->__state, (state_value)); \ 252 } while (0) 253 254 /* 255 * set_special_state() should be used for those states when the blocking task 256 * can not use the regular condition based wait-loop. In that case we must 257 * serialize against wakeups such that any possible in-flight TASK_RUNNING 258 * stores will not collide with our state change. 259 */ 260 #define set_special_state(state_value) \ 261 do { \ 262 unsigned long flags; /* may shadow */ \ 263 \ 264 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 265 debug_special_state_change((state_value)); \ 266 trace_set_current_state(state_value); \ 267 WRITE_ONCE(current->__state, (state_value)); \ 268 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 269 } while (0) 270 271 /* 272 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 273 * 274 * RT's spin/rwlock substitutions are state preserving. The state of the 275 * task when blocking on the lock is saved in task_struct::saved_state and 276 * restored after the lock has been acquired. These operations are 277 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 278 * lock related wakeups while the task is blocked on the lock are 279 * redirected to operate on task_struct::saved_state to ensure that these 280 * are not dropped. On restore task_struct::saved_state is set to 281 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 282 * 283 * The lock operation looks like this: 284 * 285 * current_save_and_set_rtlock_wait_state(); 286 * for (;;) { 287 * if (try_lock()) 288 * break; 289 * raw_spin_unlock_irq(&lock->wait_lock); 290 * schedule_rtlock(); 291 * raw_spin_lock_irq(&lock->wait_lock); 292 * set_current_state(TASK_RTLOCK_WAIT); 293 * } 294 * current_restore_rtlock_saved_state(); 295 */ 296 #define current_save_and_set_rtlock_wait_state() \ 297 do { \ 298 lockdep_assert_irqs_disabled(); \ 299 raw_spin_lock(¤t->pi_lock); \ 300 current->saved_state = current->__state; \ 301 debug_rtlock_wait_set_state(); \ 302 trace_set_current_state(TASK_RTLOCK_WAIT); \ 303 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 304 raw_spin_unlock(¤t->pi_lock); \ 305 } while (0); 306 307 #define current_restore_rtlock_saved_state() \ 308 do { \ 309 lockdep_assert_irqs_disabled(); \ 310 raw_spin_lock(¤t->pi_lock); \ 311 debug_rtlock_wait_restore_state(); \ 312 trace_set_current_state(current->saved_state); \ 313 WRITE_ONCE(current->__state, current->saved_state); \ 314 current->saved_state = TASK_RUNNING; \ 315 raw_spin_unlock(¤t->pi_lock); \ 316 } while (0); 317 318 #define get_current_state() READ_ONCE(current->__state) 319 320 /* 321 * Define the task command name length as enum, then it can be visible to 322 * BPF programs. 323 */ 324 enum { 325 TASK_COMM_LEN = 16, 326 }; 327 328 extern void sched_tick(void); 329 330 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 331 332 extern long schedule_timeout(long timeout); 333 extern long schedule_timeout_interruptible(long timeout); 334 extern long schedule_timeout_killable(long timeout); 335 extern long schedule_timeout_uninterruptible(long timeout); 336 extern long schedule_timeout_idle(long timeout); 337 asmlinkage void schedule(void); 338 extern void schedule_preempt_disabled(void); 339 asmlinkage void preempt_schedule_irq(void); 340 #ifdef CONFIG_PREEMPT_RT 341 extern void schedule_rtlock(void); 342 #endif 343 344 extern int __must_check io_schedule_prepare(void); 345 extern void io_schedule_finish(int token); 346 extern long io_schedule_timeout(long timeout); 347 extern void io_schedule(void); 348 349 /* wrapper functions to trace from this header file */ 350 DECLARE_TRACEPOINT(sched_set_state_tp); 351 extern void __trace_set_current_state(int state_value); 352 DECLARE_TRACEPOINT(sched_set_need_resched_tp); 353 extern void __trace_set_need_resched(struct task_struct *curr, int tif); 354 355 /** 356 * struct prev_cputime - snapshot of system and user cputime 357 * @utime: time spent in user mode 358 * @stime: time spent in system mode 359 * @lock: protects the above two fields 360 * 361 * Stores previous user/system time values such that we can guarantee 362 * monotonicity. 363 */ 364 struct prev_cputime { 365 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 366 u64 utime; 367 u64 stime; 368 raw_spinlock_t lock; 369 #endif 370 }; 371 372 enum vtime_state { 373 /* Task is sleeping or running in a CPU with VTIME inactive: */ 374 VTIME_INACTIVE = 0, 375 /* Task is idle */ 376 VTIME_IDLE, 377 /* Task runs in kernelspace in a CPU with VTIME active: */ 378 VTIME_SYS, 379 /* Task runs in userspace in a CPU with VTIME active: */ 380 VTIME_USER, 381 /* Task runs as guests in a CPU with VTIME active: */ 382 VTIME_GUEST, 383 }; 384 385 struct vtime { 386 seqcount_t seqcount; 387 unsigned long long starttime; 388 enum vtime_state state; 389 unsigned int cpu; 390 u64 utime; 391 u64 stime; 392 u64 gtime; 393 }; 394 395 /* 396 * Utilization clamp constraints. 397 * @UCLAMP_MIN: Minimum utilization 398 * @UCLAMP_MAX: Maximum utilization 399 * @UCLAMP_CNT: Utilization clamp constraints count 400 */ 401 enum uclamp_id { 402 UCLAMP_MIN = 0, 403 UCLAMP_MAX, 404 UCLAMP_CNT 405 }; 406 407 extern struct root_domain def_root_domain; 408 extern struct mutex sched_domains_mutex; 409 extern void sched_domains_mutex_lock(void); 410 extern void sched_domains_mutex_unlock(void); 411 412 struct sched_param { 413 int sched_priority; 414 }; 415 416 struct sched_info { 417 #ifdef CONFIG_SCHED_INFO 418 /* Cumulative counters: */ 419 420 /* # of times we have run on this CPU: */ 421 unsigned long pcount; 422 423 /* Time spent waiting on a runqueue: */ 424 unsigned long long run_delay; 425 426 /* Max time spent waiting on a runqueue: */ 427 unsigned long long max_run_delay; 428 429 /* Min time spent waiting on a runqueue: */ 430 unsigned long long min_run_delay; 431 432 /* Timestamps: */ 433 434 /* When did we last run on a CPU? */ 435 unsigned long long last_arrival; 436 437 /* When were we last queued to run? */ 438 unsigned long long last_queued; 439 440 /* Timestamp of max time spent waiting on a runqueue: */ 441 struct timespec64 max_run_delay_ts; 442 443 #endif /* CONFIG_SCHED_INFO */ 444 }; 445 446 /* 447 * Integer metrics need fixed point arithmetic, e.g., sched/fair 448 * has a few: load, load_avg, util_avg, freq, and capacity. 449 * 450 * We define a basic fixed point arithmetic range, and then formalize 451 * all these metrics based on that basic range. 452 */ 453 # define SCHED_FIXEDPOINT_SHIFT 10 454 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 455 456 /* Increase resolution of cpu_capacity calculations */ 457 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 458 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 459 460 struct load_weight { 461 unsigned long weight; 462 u32 inv_weight; 463 }; 464 465 /* 466 * The load/runnable/util_avg accumulates an infinite geometric series 467 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 468 * 469 * [load_avg definition] 470 * 471 * load_avg = runnable% * scale_load_down(load) 472 * 473 * [runnable_avg definition] 474 * 475 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 476 * 477 * [util_avg definition] 478 * 479 * util_avg = running% * SCHED_CAPACITY_SCALE 480 * 481 * where runnable% is the time ratio that a sched_entity is runnable and 482 * running% the time ratio that a sched_entity is running. 483 * 484 * For cfs_rq, they are the aggregated values of all runnable and blocked 485 * sched_entities. 486 * 487 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 488 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 489 * for computing those signals (see update_rq_clock_pelt()) 490 * 491 * N.B., the above ratios (runnable% and running%) themselves are in the 492 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 493 * to as large a range as necessary. This is for example reflected by 494 * util_avg's SCHED_CAPACITY_SCALE. 495 * 496 * [Overflow issue] 497 * 498 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 499 * with the highest load (=88761), always runnable on a single cfs_rq, 500 * and should not overflow as the number already hits PID_MAX_LIMIT. 501 * 502 * For all other cases (including 32-bit kernels), struct load_weight's 503 * weight will overflow first before we do, because: 504 * 505 * Max(load_avg) <= Max(load.weight) 506 * 507 * Then it is the load_weight's responsibility to consider overflow 508 * issues. 509 */ 510 struct sched_avg { 511 u64 last_update_time; 512 u64 load_sum; 513 u64 runnable_sum; 514 u32 util_sum; 515 u32 period_contrib; 516 unsigned long load_avg; 517 unsigned long runnable_avg; 518 unsigned long util_avg; 519 unsigned int util_est; 520 } ____cacheline_aligned; 521 522 /* 523 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 524 * updates. When a task is dequeued, its util_est should not be updated if its 525 * util_avg has not been updated in the meantime. 526 * This information is mapped into the MSB bit of util_est at dequeue time. 527 * Since max value of util_est for a task is 1024 (PELT util_avg for a task) 528 * it is safe to use MSB. 529 */ 530 #define UTIL_EST_WEIGHT_SHIFT 2 531 #define UTIL_AVG_UNCHANGED 0x80000000 532 533 struct sched_statistics { 534 #ifdef CONFIG_SCHEDSTATS 535 u64 wait_start; 536 u64 wait_max; 537 u64 wait_count; 538 u64 wait_sum; 539 u64 iowait_count; 540 u64 iowait_sum; 541 542 u64 sleep_start; 543 u64 sleep_max; 544 s64 sum_sleep_runtime; 545 546 u64 block_start; 547 u64 block_max; 548 s64 sum_block_runtime; 549 550 s64 exec_max; 551 u64 slice_max; 552 553 u64 nr_migrations_cold; 554 u64 nr_failed_migrations_affine; 555 u64 nr_failed_migrations_running; 556 u64 nr_failed_migrations_hot; 557 u64 nr_forced_migrations; 558 559 u64 nr_wakeups; 560 u64 nr_wakeups_sync; 561 u64 nr_wakeups_migrate; 562 u64 nr_wakeups_local; 563 u64 nr_wakeups_remote; 564 u64 nr_wakeups_affine; 565 u64 nr_wakeups_affine_attempts; 566 u64 nr_wakeups_passive; 567 u64 nr_wakeups_idle; 568 569 #ifdef CONFIG_SCHED_CORE 570 u64 core_forceidle_sum; 571 #endif 572 #endif /* CONFIG_SCHEDSTATS */ 573 } ____cacheline_aligned; 574 575 struct sched_entity { 576 /* For load-balancing: */ 577 struct load_weight load; 578 struct rb_node run_node; 579 u64 deadline; 580 u64 min_vruntime; 581 u64 min_slice; 582 u64 max_slice; 583 584 struct list_head group_node; 585 unsigned char on_rq; 586 unsigned char sched_delayed; 587 unsigned char rel_deadline; 588 unsigned char custom_slice; 589 /* hole */ 590 591 u64 exec_start; 592 u64 sum_exec_runtime; 593 u64 prev_sum_exec_runtime; 594 u64 vruntime; 595 /* Approximated virtual lag: */ 596 s64 vlag; 597 /* 'Protected' deadline, to give out minimum quantums: */ 598 u64 vprot; 599 u64 slice; 600 601 u64 nr_migrations; 602 603 #ifdef CONFIG_FAIR_GROUP_SCHED 604 int depth; 605 struct sched_entity *parent; 606 /* rq on which this entity is (to be) queued: */ 607 struct cfs_rq *cfs_rq; 608 /* rq "owned" by this entity/group: */ 609 struct cfs_rq *my_q; 610 /* cached value of my_q->h_nr_running */ 611 unsigned long runnable_weight; 612 #endif 613 614 /* 615 * Per entity load average tracking. 616 * 617 * Put into separate cache line so it does not 618 * collide with read-mostly values above. 619 */ 620 struct sched_avg avg; 621 }; 622 623 struct sched_rt_entity { 624 struct list_head run_list; 625 unsigned long timeout; 626 unsigned long watchdog_stamp; 627 unsigned int time_slice; 628 unsigned short on_rq; 629 unsigned short on_list; 630 631 struct sched_rt_entity *back; 632 #ifdef CONFIG_RT_GROUP_SCHED 633 struct sched_rt_entity *parent; 634 /* rq on which this entity is (to be) queued: */ 635 struct rt_rq *rt_rq; 636 /* rq "owned" by this entity/group: */ 637 struct rt_rq *my_q; 638 #endif 639 } __randomize_layout; 640 641 struct rq_flags; 642 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *, struct rq_flags *rf); 643 644 struct sched_dl_entity { 645 struct rb_node rb_node; 646 647 /* 648 * Original scheduling parameters. Copied here from sched_attr 649 * during sched_setattr(), they will remain the same until 650 * the next sched_setattr(). 651 */ 652 u64 dl_runtime; /* Maximum runtime for each instance */ 653 u64 dl_deadline; /* Relative deadline of each instance */ 654 u64 dl_period; /* Separation of two instances (period) */ 655 u64 dl_bw; /* dl_runtime / dl_period */ 656 u64 dl_density; /* dl_runtime / dl_deadline */ 657 658 /* 659 * Actual scheduling parameters. Initialized with the values above, 660 * they are continuously updated during task execution. Note that 661 * the remaining runtime could be < 0 in case we are in overrun. 662 */ 663 s64 runtime; /* Remaining runtime for this instance */ 664 u64 deadline; /* Absolute deadline for this instance */ 665 unsigned int flags; /* Specifying the scheduler behaviour */ 666 667 /* 668 * Some bool flags: 669 * 670 * @dl_throttled tells if we exhausted the runtime. If so, the 671 * task has to wait for a replenishment to be performed at the 672 * next firing of dl_timer. 673 * 674 * @dl_yielded tells if task gave up the CPU before consuming 675 * all its available runtime during the last job. 676 * 677 * @dl_non_contending tells if the task is inactive while still 678 * contributing to the active utilization. In other words, it 679 * indicates if the inactive timer has been armed and its handler 680 * has not been executed yet. This flag is useful to avoid race 681 * conditions between the inactive timer handler and the wakeup 682 * code. 683 * 684 * @dl_overrun tells if the task asked to be informed about runtime 685 * overruns. 686 * 687 * @dl_server tells if this is a server entity. 688 * 689 * @dl_server_active tells if the dlserver is active(started). 690 * dlserver is started on first cfs enqueue on an idle runqueue 691 * and is stopped when a dequeue results in 0 cfs tasks on the 692 * runqueue. In other words, dlserver is active only when cpu's 693 * runqueue has atleast one cfs task. 694 * 695 * @dl_defer tells if this is a deferred or regular server. For 696 * now only defer server exists. 697 * 698 * @dl_defer_armed tells if the deferrable server is waiting 699 * for the replenishment timer to activate it. 700 * 701 * @dl_defer_running tells if the deferrable server is actually 702 * running, skipping the defer phase. 703 * 704 * @dl_defer_idle tracks idle state 705 * 706 * @dl_bw_attached tells if this server's bandwidth currently 707 * contributes to the root domain's total_bw. Only meaningful for server 708 * entities (@dl_server == 1). Allows toggling the reservation on/off 709 * without losing the configured @dl_runtime/@dl_period. 710 */ 711 unsigned int dl_throttled : 1; 712 unsigned int dl_yielded : 1; 713 unsigned int dl_non_contending : 1; 714 unsigned int dl_overrun : 1; 715 unsigned int dl_server : 1; 716 unsigned int dl_server_active : 1; 717 unsigned int dl_defer : 1; 718 unsigned int dl_defer_armed : 1; 719 unsigned int dl_defer_running : 1; 720 unsigned int dl_defer_idle : 1; 721 unsigned int dl_bw_attached : 1; 722 723 /* 724 * Bandwidth enforcement timer. Each -deadline task has its 725 * own bandwidth to be enforced, thus we need one timer per task. 726 */ 727 struct hrtimer dl_timer; 728 729 /* 730 * Inactive timer, responsible for decreasing the active utilization 731 * at the "0-lag time". When a -deadline task blocks, it contributes 732 * to GRUB's active utilization until the "0-lag time", hence a 733 * timer is needed to decrease the active utilization at the correct 734 * time. 735 */ 736 struct hrtimer inactive_timer; 737 738 /* 739 * Bits for DL-server functionality. Also see the comment near 740 * dl_server_update(). 741 * 742 * @rq the runqueue this server is for 743 */ 744 struct rq *rq; 745 dl_server_pick_f server_pick_task; 746 747 #ifdef CONFIG_RT_MUTEXES 748 /* 749 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 750 * pi_se points to the donor, otherwise points to the dl_se it belongs 751 * to (the original one/itself). 752 */ 753 struct sched_dl_entity *pi_se; 754 #endif 755 }; 756 757 #ifdef CONFIG_UCLAMP_TASK 758 /* Number of utilization clamp buckets (shorter alias) */ 759 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 760 761 /* 762 * Utilization clamp for a scheduling entity 763 * @value: clamp value "assigned" to a se 764 * @bucket_id: bucket index corresponding to the "assigned" value 765 * @active: the se is currently refcounted in a rq's bucket 766 * @user_defined: the requested clamp value comes from user-space 767 * 768 * The bucket_id is the index of the clamp bucket matching the clamp value 769 * which is pre-computed and stored to avoid expensive integer divisions from 770 * the fast path. 771 * 772 * The active bit is set whenever a task has got an "effective" value assigned, 773 * which can be different from the clamp value "requested" from user-space. 774 * This allows to know a task is refcounted in the rq's bucket corresponding 775 * to the "effective" bucket_id. 776 * 777 * The user_defined bit is set whenever a task has got a task-specific clamp 778 * value requested from userspace, i.e. the system defaults apply to this task 779 * just as a restriction. This allows to relax default clamps when a less 780 * restrictive task-specific value has been requested, thus allowing to 781 * implement a "nice" semantic. For example, a task running with a 20% 782 * default boost can still drop its own boosting to 0%. 783 */ 784 struct uclamp_se { 785 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 786 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 787 unsigned int active : 1; 788 unsigned int user_defined : 1; 789 }; 790 #endif /* CONFIG_UCLAMP_TASK */ 791 792 union rcu_special { 793 struct { 794 u8 blocked; 795 u8 need_qs; 796 u8 exp_hint; /* Hint for performance. */ 797 u8 need_mb; /* Readers need smp_mb(). */ 798 } b; /* Bits. */ 799 u32 s; /* Set of bits. */ 800 }; 801 802 enum perf_event_task_context { 803 perf_invalid_context = -1, 804 perf_hw_context = 0, 805 perf_sw_context, 806 perf_nr_task_contexts, 807 }; 808 809 /* 810 * Number of contexts where an event can trigger: 811 * task, softirq, hardirq, nmi. 812 */ 813 #define PERF_NR_CONTEXTS 4 814 815 struct wake_q_node { 816 struct wake_q_node *next; 817 }; 818 819 struct kmap_ctrl { 820 #ifdef CONFIG_KMAP_LOCAL 821 int idx; 822 pte_t pteval[KM_MAX_IDX]; 823 #endif 824 }; 825 826 struct task_struct { 827 #ifdef CONFIG_THREAD_INFO_IN_TASK 828 /* 829 * For reasons of header soup (see current_thread_info()), this 830 * must be the first element of task_struct. 831 */ 832 struct thread_info thread_info; 833 #endif 834 unsigned int __state; 835 836 /* saved state for "spinlock sleepers" */ 837 unsigned int saved_state; 838 839 /* 840 * This begins the randomizable portion of task_struct. Only 841 * scheduling-critical items should be added above here. 842 */ 843 randomized_struct_fields_start 844 845 void *stack; 846 refcount_t usage; 847 /* Per task flags (PF_*), defined further below: */ 848 unsigned int flags; 849 unsigned int ptrace; 850 851 #ifdef CONFIG_MEM_ALLOC_PROFILING 852 struct alloc_tag *alloc_tag; 853 #endif 854 855 u8 on_cpu; 856 u8 on_rq; 857 u8 is_blocked; 858 u8 __pad; 859 860 struct __call_single_node wake_entry; 861 unsigned int wakee_flips; 862 unsigned long wakee_flip_decay_ts; 863 struct task_struct *last_wakee; 864 865 /* 866 * recent_used_cpu is initially set as the last CPU used by a task 867 * that wakes affine another task. Waker/wakee relationships can 868 * push tasks around a CPU where each wakeup moves to the next one. 869 * Tracking a recently used CPU allows a quick search for a recently 870 * used CPU that may be idle. 871 */ 872 int recent_used_cpu; 873 int wake_cpu; 874 875 int prio; 876 int static_prio; 877 int normal_prio; 878 unsigned int rt_priority; 879 880 struct sched_entity se; 881 struct sched_rt_entity rt; 882 struct sched_dl_entity dl; 883 struct sched_dl_entity *dl_server; 884 #ifdef CONFIG_SCHED_CLASS_EXT 885 struct sched_ext_entity scx; 886 #endif 887 const struct sched_class *sched_class; 888 889 #ifdef CONFIG_SCHED_CORE 890 struct rb_node core_node; 891 unsigned long core_cookie; 892 unsigned int core_occupation; 893 #endif 894 895 #ifdef CONFIG_CGROUP_SCHED 896 struct task_group *sched_task_group; 897 #ifdef CONFIG_CFS_BANDWIDTH 898 struct callback_head sched_throttle_work; 899 struct list_head throttle_node; 900 bool throttled; 901 #endif 902 #endif 903 904 905 #ifdef CONFIG_UCLAMP_TASK 906 /* 907 * Clamp values requested for a scheduling entity. 908 * Must be updated with task_rq_lock() held. 909 */ 910 struct uclamp_se uclamp_req[UCLAMP_CNT]; 911 /* 912 * Effective clamp values used for a scheduling entity. 913 * Must be updated with task_rq_lock() held. 914 */ 915 struct uclamp_se uclamp[UCLAMP_CNT]; 916 #endif 917 918 struct sched_statistics stats; 919 920 #ifdef CONFIG_PREEMPT_NOTIFIERS 921 /* List of struct preempt_notifier: */ 922 struct hlist_head preempt_notifiers; 923 #endif 924 925 #ifdef CONFIG_BLK_DEV_IO_TRACE 926 unsigned int btrace_seq; 927 #endif 928 929 unsigned int policy; 930 unsigned long max_allowed_capacity; 931 int nr_cpus_allowed; 932 const cpumask_t *cpus_ptr; 933 cpumask_t *user_cpus_ptr; 934 cpumask_t cpus_mask; 935 void *migration_pending; 936 unsigned short migration_disabled; 937 unsigned short migration_flags; 938 939 #ifdef CONFIG_PREEMPT_RCU 940 int rcu_read_lock_nesting; 941 union rcu_special rcu_read_unlock_special; 942 struct list_head rcu_node_entry; 943 struct rcu_node *rcu_blocked_node; 944 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 945 946 #ifdef CONFIG_TASKS_RCU 947 unsigned long rcu_tasks_nvcsw; 948 u8 rcu_tasks_holdout; 949 u8 rcu_tasks_idx; 950 int rcu_tasks_idle_cpu; 951 struct list_head rcu_tasks_holdout_list; 952 int rcu_tasks_exit_cpu; 953 struct list_head rcu_tasks_exit_list; 954 #endif /* #ifdef CONFIG_TASKS_RCU */ 955 956 #ifdef CONFIG_TASKS_TRACE_RCU 957 int trc_reader_nesting; 958 struct srcu_ctr __percpu *trc_reader_scp; 959 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 960 961 #ifdef CONFIG_TRIVIAL_PREEMPT_RCU 962 int rcu_trivial_preempt_nesting; 963 #endif /* #ifdef CONFIG_TRIVIAL_PREEMPT_RCU */ 964 965 struct sched_info sched_info; 966 967 struct list_head tasks; 968 struct plist_node pushable_tasks; 969 struct rb_node pushable_dl_tasks; 970 971 struct mm_struct *mm; 972 struct mm_struct *active_mm; 973 974 struct task_exec_state __rcu *exec_state; 975 976 int exit_state; 977 int exit_code; 978 int exit_signal; 979 /* The signal sent when the parent dies: */ 980 int pdeath_signal; 981 /* JOBCTL_*, siglock protected: */ 982 unsigned long jobctl; 983 984 /* Used for emulating ABI behavior of previous Linux versions: */ 985 unsigned int personality; 986 987 /* Scheduler bits, serialized by scheduler locks: */ 988 unsigned sched_reset_on_fork:1; 989 unsigned sched_contributes_to_load:1; 990 unsigned sched_migrated:1; 991 unsigned sched_task_hot:1; 992 993 /* Force alignment to the next boundary: */ 994 unsigned :0; 995 996 /* Unserialized, strictly 'current' */ 997 998 /* 999 * This field must not be in the scheduler word above due to wakelist 1000 * queueing no longer being serialized by p->on_cpu. However: 1001 * 1002 * p->XXX = X; ttwu() 1003 * schedule() if (p->on_rq && ..) // false 1004 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 1005 * deactivate_task() ttwu_queue_wakelist()) 1006 * p->on_rq = 0; p->sched_remote_wakeup = Y; 1007 * 1008 * guarantees all stores of 'current' are visible before 1009 * ->sched_remote_wakeup gets used, so it can be in this word. 1010 */ 1011 unsigned sched_remote_wakeup:1; 1012 #ifdef CONFIG_RT_MUTEXES 1013 unsigned sched_rt_mutex:1; 1014 #endif 1015 1016 /* Bit to tell TOMOYO we're in execve(): */ 1017 unsigned in_execve:1; 1018 unsigned in_iowait:1; 1019 #ifndef TIF_RESTORE_SIGMASK 1020 unsigned restore_sigmask:1; 1021 #endif 1022 #ifdef CONFIG_MEMCG_V1 1023 unsigned in_user_fault:1; 1024 #endif 1025 #ifdef CONFIG_LRU_GEN 1026 /* whether the LRU algorithm may apply to this access */ 1027 unsigned in_lru_fault:1; 1028 #endif 1029 #ifdef CONFIG_COMPAT_BRK 1030 unsigned brk_randomized:1; 1031 #endif 1032 #ifdef CONFIG_CGROUPS 1033 /* disallow userland-initiated cgroup migration */ 1034 unsigned no_cgroup_migration:1; 1035 /* task is frozen/stopped (used by the cgroup freezer) */ 1036 unsigned frozen:1; 1037 #endif 1038 #ifdef CONFIG_BLK_CGROUP 1039 unsigned use_memdelay:1; 1040 #endif 1041 #ifdef CONFIG_PSI 1042 /* Stalled due to lack of memory */ 1043 unsigned in_memstall:1; 1044 #endif 1045 #ifdef CONFIG_PAGE_OWNER 1046 /* Used by page_owner=on to detect recursion in page tracking. */ 1047 unsigned in_page_owner:1; 1048 #endif 1049 #ifdef CONFIG_EVENTFD 1050 /* Recursion prevention for eventfd_signal() */ 1051 unsigned in_eventfd:1; 1052 #endif 1053 #ifdef CONFIG_ARCH_HAS_CPU_PASID 1054 unsigned pasid_activated:1; 1055 #endif 1056 #ifdef CONFIG_X86_BUS_LOCK_DETECT 1057 unsigned reported_split_lock:1; 1058 #endif 1059 #ifdef CONFIG_TASK_DELAY_ACCT 1060 /* delay due to memory thrashing */ 1061 unsigned in_thrashing:1; 1062 #endif 1063 unsigned in_nf_duplicate:1; 1064 #ifdef CONFIG_PREEMPT_RT 1065 struct netdev_xmit net_xmit; 1066 #endif 1067 unsigned long atomic_flags; /* Flags requiring atomic access. */ 1068 1069 struct restart_block restart_block; 1070 1071 pid_t pid; 1072 pid_t tgid; 1073 1074 #ifdef CONFIG_STACKPROTECTOR 1075 /* Canary value for the -fstack-protector GCC feature: */ 1076 unsigned long stack_canary; 1077 #endif 1078 /* 1079 * Pointers to the (original) parent process, youngest child, younger sibling, 1080 * older sibling, respectively. (p->father can be replaced with 1081 * p->real_parent->pid) 1082 */ 1083 1084 /* Real parent process: */ 1085 struct task_struct __rcu *real_parent; 1086 1087 /* Recipient of SIGCHLD, wait4() reports: */ 1088 struct task_struct __rcu *parent; 1089 1090 /* 1091 * Children/sibling form the list of natural children: 1092 */ 1093 struct list_head children; 1094 struct list_head sibling; 1095 struct task_struct *group_leader; 1096 1097 /* 1098 * 'ptraced' is the list of tasks this task is using ptrace() on. 1099 * 1100 * This includes both natural children and PTRACE_ATTACH targets. 1101 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 1102 */ 1103 struct list_head ptraced; 1104 struct list_head ptrace_entry; 1105 1106 /* PID/PID hash table linkage. */ 1107 struct pid *thread_pid; 1108 struct hlist_node pid_links[PIDTYPE_MAX]; 1109 struct list_head thread_node; 1110 1111 struct completion *vfork_done; 1112 1113 /* CLONE_CHILD_SETTID: */ 1114 int __user *set_child_tid; 1115 1116 /* CLONE_CHILD_CLEARTID: */ 1117 int __user *clear_child_tid; 1118 1119 /* PF_KTHREAD | PF_IO_WORKER */ 1120 void *worker_private; 1121 1122 u64 utime; 1123 u64 stime; 1124 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1125 u64 utimescaled; 1126 u64 stimescaled; 1127 #endif 1128 u64 gtime; 1129 struct prev_cputime prev_cputime; 1130 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1131 struct vtime vtime; 1132 #endif 1133 1134 #ifdef CONFIG_NO_HZ_FULL 1135 atomic_t tick_dep_mask; 1136 #endif 1137 /* Context switch counts: */ 1138 unsigned long nvcsw; 1139 unsigned long nivcsw; 1140 1141 /* Monotonic time in nsecs: */ 1142 u64 start_time; 1143 1144 /* Boot based time in nsecs: */ 1145 u64 start_boottime; 1146 1147 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1148 unsigned long min_flt; 1149 unsigned long maj_flt; 1150 1151 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1152 struct posix_cputimers posix_cputimers; 1153 1154 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1155 struct posix_cputimers_work posix_cputimers_work; 1156 #endif 1157 1158 /* Process credentials: */ 1159 1160 /* Tracer's credentials at attach: */ 1161 const struct cred __rcu *ptracer_cred; 1162 1163 /* Objective and real subjective task credentials (COW): */ 1164 const struct cred __rcu *real_cred; 1165 1166 /* Effective (overridable) subjective task credentials (COW): */ 1167 const struct cred __rcu *cred; 1168 1169 #ifdef CONFIG_KEYS 1170 /* Cached requested key. */ 1171 struct key *cached_requested_key; 1172 #endif 1173 1174 /* 1175 * executable name, excluding path. 1176 * 1177 * - normally initialized by begin_new_exec() 1178 * - set it with set_task_comm() to ensure it is always 1179 * NUL-terminated and zero-padded 1180 */ 1181 char comm[TASK_COMM_LEN]; 1182 1183 struct nameidata *nameidata; 1184 1185 #ifdef CONFIG_SYSVIPC 1186 struct sysv_sem sysvsem; 1187 struct sysv_shm sysvshm; 1188 #endif 1189 #ifdef CONFIG_DETECT_HUNG_TASK 1190 unsigned long last_switch_count; 1191 unsigned long last_switch_time; 1192 #endif 1193 /* Filesystem information: */ 1194 struct fs_struct *fs; 1195 1196 /* Open file information: */ 1197 struct files_struct *files; 1198 1199 #ifdef CONFIG_IO_URING 1200 struct io_uring_task *io_uring; 1201 struct io_restriction *io_uring_restrict; 1202 #endif 1203 1204 /* Namespaces: */ 1205 struct nsproxy *nsproxy; 1206 1207 /* Signal handlers: */ 1208 struct signal_struct *signal; 1209 struct sighand_struct __rcu *sighand; 1210 sigset_t blocked; 1211 sigset_t real_blocked; 1212 /* Restored if set_restore_sigmask() was used: */ 1213 sigset_t saved_sigmask; 1214 struct sigpending pending; 1215 unsigned long sas_ss_sp; 1216 size_t sas_ss_size; 1217 unsigned int sas_ss_flags; 1218 1219 struct callback_head *task_works; 1220 1221 #ifdef CONFIG_AUDIT 1222 #ifdef CONFIG_AUDITSYSCALL 1223 struct audit_context *audit_context; 1224 #endif 1225 kuid_t loginuid; 1226 unsigned int sessionid; 1227 #endif 1228 struct seccomp seccomp; 1229 struct syscall_user_dispatch syscall_dispatch; 1230 1231 /* Thread group tracking: */ 1232 u64 parent_exec_id; 1233 u64 self_exec_id; 1234 1235 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1236 spinlock_t alloc_lock; 1237 1238 /* Protection of the PI data structures: */ 1239 raw_spinlock_t pi_lock; 1240 1241 struct wake_q_node wake_q; 1242 1243 #ifdef CONFIG_RT_MUTEXES 1244 /* PI waiters blocked on a rt_mutex held by this task: */ 1245 struct rb_root_cached pi_waiters; 1246 /* Updated under owner's pi_lock and rq lock */ 1247 struct task_struct *pi_top_task; 1248 /* Deadlock detection and priority inheritance handling: */ 1249 struct rt_mutex_waiter *pi_blocked_on; 1250 #endif 1251 1252 struct mutex *blocked_on; /* lock we're blocked on */ 1253 raw_spinlock_t blocked_lock; 1254 1255 /* 1256 * The task that is boosting this task; a back link for the current 1257 * donor stack. Set in schedule() -> find_proxy_task() and only stable 1258 * under preempt_disable(). 1259 */ 1260 struct task_struct *blocked_donor; 1261 1262 #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER 1263 /* 1264 * Encoded lock address causing task block (lower 2 bits = type from 1265 * <linux/hung_task.h>). Accessed via hung_task_*() helpers. 1266 */ 1267 unsigned long blocker; 1268 #endif 1269 1270 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1271 int non_block_count; 1272 #endif 1273 1274 #ifdef CONFIG_TRACE_IRQFLAGS 1275 struct irqtrace_events irqtrace; 1276 unsigned int hardirq_threaded; 1277 u64 hardirq_chain_key; 1278 int softirqs_enabled; 1279 int softirq_context; 1280 int irq_config; 1281 #endif 1282 #ifdef CONFIG_PREEMPT_RT 1283 int softirq_disable_cnt; 1284 #endif 1285 1286 #ifdef CONFIG_LOCKDEP 1287 # define MAX_LOCK_DEPTH 48UL 1288 u64 curr_chain_key; 1289 int lockdep_depth; 1290 unsigned int lockdep_recursion; 1291 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1292 #endif 1293 1294 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1295 unsigned int in_ubsan; 1296 #endif 1297 1298 /* Journalling filesystem info: */ 1299 void *journal_info; 1300 1301 /* Stacked block device info: */ 1302 struct bio_list *bio_list; 1303 1304 /* Stack plugging: */ 1305 struct blk_plug *plug; 1306 1307 /* VM state: */ 1308 struct reclaim_state *reclaim_state; 1309 1310 struct io_context *io_context; 1311 1312 #ifdef CONFIG_COMPACTION 1313 struct capture_control *capture_control; 1314 #endif 1315 /* Ptrace state: */ 1316 unsigned long ptrace_message; 1317 kernel_siginfo_t *last_siginfo; 1318 1319 struct task_io_accounting ioac; 1320 #ifdef CONFIG_PSI 1321 /* Pressure stall state */ 1322 unsigned int psi_flags; 1323 #endif 1324 #ifdef CONFIG_TASK_XACCT 1325 /* Accumulated RSS usage: */ 1326 u64 acct_rss_mem1; 1327 /* Accumulated virtual memory usage: */ 1328 u64 acct_vm_mem1; 1329 /* stime + utime since last update: */ 1330 u64 acct_timexpd; 1331 #endif 1332 #ifdef CONFIG_CPUSETS 1333 /* Protected by ->alloc_lock: */ 1334 nodemask_t mems_allowed; 1335 /* Sequence number to catch updates: */ 1336 seqcount_spinlock_t mems_allowed_seq; 1337 int cpuset_mem_spread_rotor; 1338 #endif 1339 #ifdef CONFIG_CGROUPS 1340 /* Control Group info protected by css_set_lock: */ 1341 struct css_set __rcu *cgroups; 1342 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1343 struct list_head cg_list; 1344 #ifdef CONFIG_PREEMPT_RT 1345 struct llist_node cg_dead_lnode; 1346 #endif /* CONFIG_PREEMPT_RT */ 1347 #endif /* CONFIG_CGROUPS */ 1348 #ifdef CONFIG_X86_CPU_RESCTRL 1349 u32 closid; 1350 u32 rmid; 1351 #endif 1352 1353 struct futex_sched_data futex; 1354 1355 #ifdef CONFIG_PERF_EVENTS 1356 u8 perf_recursion[PERF_NR_CONTEXTS]; 1357 struct perf_event_context *perf_event_ctxp; 1358 struct mutex perf_event_mutex; 1359 struct list_head perf_event_list; 1360 struct perf_ctx_data __rcu *perf_ctx_data; 1361 #endif 1362 #ifdef CONFIG_DEBUG_PREEMPT 1363 unsigned long preempt_disable_ip; 1364 #endif 1365 #ifdef CONFIG_NUMA 1366 /* Protected by alloc_lock: */ 1367 struct mempolicy *mempolicy; 1368 short il_prev; 1369 u8 il_weight; 1370 short pref_node_fork; 1371 #endif 1372 #ifdef CONFIG_NUMA_BALANCING 1373 int numa_scan_seq; 1374 unsigned int numa_scan_period; 1375 unsigned int numa_scan_period_max; 1376 int numa_preferred_nid; 1377 unsigned long numa_migrate_retry; 1378 /* Migration stamp: */ 1379 u64 node_stamp; 1380 u64 last_task_numa_placement; 1381 u64 last_sum_exec_runtime; 1382 struct callback_head numa_work; 1383 1384 /* 1385 * This pointer is only modified for current in syscall and 1386 * pagefault context (and for tasks being destroyed), so it can be read 1387 * from any of the following contexts: 1388 * - RCU read-side critical section 1389 * - current->numa_group from everywhere 1390 * - task's runqueue locked, task not running 1391 */ 1392 struct numa_group __rcu *numa_group; 1393 1394 /* 1395 * numa_faults is an array split into four regions: 1396 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1397 * in this precise order. 1398 * 1399 * faults_memory: Exponential decaying average of faults on a per-node 1400 * basis. Scheduling placement decisions are made based on these 1401 * counts. The values remain static for the duration of a PTE scan. 1402 * faults_cpu: Track the nodes the process was running on when a NUMA 1403 * hinting fault was incurred. 1404 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1405 * during the current scan window. When the scan completes, the counts 1406 * in faults_memory and faults_cpu decay and these values are copied. 1407 */ 1408 unsigned long *numa_faults; 1409 unsigned long total_numa_faults; 1410 1411 /* 1412 * numa_faults_locality tracks if faults recorded during the last 1413 * scan window were remote/local or failed to migrate. The task scan 1414 * period is adapted based on the locality of the faults with different 1415 * weights depending on whether they were shared or private faults 1416 */ 1417 unsigned long numa_faults_locality[3]; 1418 1419 unsigned long numa_pages_migrated; 1420 #endif /* CONFIG_NUMA_BALANCING */ 1421 1422 #ifdef CONFIG_SCHED_CACHE 1423 struct callback_head cache_work; 1424 int preferred_llc; 1425 /* 1: task was enqueued to its preferred LLC, 0 otherwise */ 1426 int pref_llc_queued; 1427 #endif 1428 1429 struct rseq_data rseq; 1430 struct sched_mm_cid mm_cid; 1431 1432 struct tlbflush_unmap_batch tlb_ubc; 1433 1434 /* Cache last used pipe for splice(): */ 1435 struct pipe_inode_info *splice_pipe; 1436 1437 struct page_frag task_frag; 1438 1439 #ifdef CONFIG_ARCH_HAS_LAZY_MMU_MODE 1440 struct lazy_mmu_state lazy_mmu_state; 1441 #endif 1442 1443 #ifdef CONFIG_TASK_DELAY_ACCT 1444 struct task_delay_info *delays; 1445 #endif 1446 1447 #ifdef CONFIG_FAULT_INJECTION 1448 int make_it_fail; 1449 unsigned int fail_nth; 1450 #endif 1451 /* 1452 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1453 * balance_dirty_pages() for a dirty throttling pause: 1454 */ 1455 int nr_dirtied; 1456 int nr_dirtied_pause; 1457 /* Start of a write-and-pause period: */ 1458 unsigned long dirty_paused_when; 1459 1460 #ifdef CONFIG_LATENCYTOP 1461 int latency_record_count; 1462 struct latency_record latency_record[LT_SAVECOUNT]; 1463 #endif 1464 /* 1465 * Time slack values; these are used to round up poll() and 1466 * select() etc timeout values. These are in nanoseconds. 1467 */ 1468 u64 timer_slack_ns; 1469 u64 default_timer_slack_ns; 1470 1471 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1472 unsigned int kasan_depth; 1473 #endif 1474 1475 #ifdef CONFIG_KCSAN 1476 struct kcsan_ctx kcsan_ctx; 1477 #ifdef CONFIG_TRACE_IRQFLAGS 1478 struct irqtrace_events kcsan_save_irqtrace; 1479 #endif 1480 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1481 int kcsan_stack_depth; 1482 #endif 1483 #endif 1484 1485 #ifdef CONFIG_KMSAN 1486 struct kmsan_ctx kmsan_ctx; 1487 #endif 1488 1489 #if IS_ENABLED(CONFIG_KUNIT) 1490 struct kunit *kunit_test; 1491 #endif 1492 1493 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1494 /* Index of current stored address in ret_stack: */ 1495 int curr_ret_stack; 1496 int curr_ret_depth; 1497 1498 /* Stack of return addresses for return function tracing: */ 1499 unsigned long *ret_stack; 1500 1501 /* Timestamp for last schedule: */ 1502 unsigned long long ftrace_timestamp; 1503 unsigned long long ftrace_sleeptime; 1504 1505 /* 1506 * Number of functions that haven't been traced 1507 * because of depth overrun: 1508 */ 1509 atomic_t trace_overrun; 1510 1511 /* Pause tracing: */ 1512 atomic_t tracing_graph_pause; 1513 #endif 1514 1515 #ifdef CONFIG_TRACING 1516 /* Bitmask and counter of trace recursion: */ 1517 unsigned long trace_recursion; 1518 #endif /* CONFIG_TRACING */ 1519 1520 #ifdef CONFIG_KCOV 1521 /* See kernel/kcov.c for more details. */ 1522 1523 /* Coverage collection mode enabled for this task (0 if disabled): */ 1524 unsigned int kcov_mode; 1525 1526 /* Size of the kcov_area: */ 1527 unsigned int kcov_size; 1528 1529 /* Buffer for coverage collection: */ 1530 void *kcov_area; 1531 1532 /* KCOV descriptor wired with this task or NULL: */ 1533 struct kcov *kcov; 1534 1535 /* KCOV common handle for remote coverage collection: */ 1536 u64 kcov_handle; 1537 1538 /* KCOV sequence number: */ 1539 int kcov_sequence; 1540 1541 /* Collect coverage from softirq context: */ 1542 unsigned int kcov_softirq; 1543 #endif 1544 1545 #ifdef CONFIG_MEMCG_V1 1546 struct mem_cgroup *memcg_in_oom; 1547 #endif 1548 1549 #ifdef CONFIG_MEMCG 1550 /* Number of pages to reclaim on returning to userland: */ 1551 unsigned int memcg_nr_pages_over_high; 1552 1553 /* Used by memcontrol for targeted memcg charge: */ 1554 struct mem_cgroup *active_memcg; 1555 1556 /* Cache for current->cgroups->memcg->nodeinfo[nid]->objcg lookups: */ 1557 struct obj_cgroup *objcg; 1558 #endif 1559 1560 #ifdef CONFIG_BLK_CGROUP 1561 struct gendisk *throttle_disk; 1562 #endif 1563 1564 #ifdef CONFIG_UPROBES 1565 struct uprobe_task *utask; 1566 #endif 1567 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1568 unsigned int sequential_io; 1569 unsigned int sequential_io_avg; 1570 #endif 1571 struct kmap_ctrl kmap_ctrl; 1572 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1573 unsigned long task_state_change; 1574 # ifdef CONFIG_PREEMPT_RT 1575 unsigned long saved_state_change; 1576 # endif 1577 #endif 1578 struct rcu_head rcu; 1579 refcount_t rcu_users; 1580 int pagefault_disabled; 1581 #ifdef CONFIG_MMU 1582 struct task_struct *oom_reaper_list; 1583 struct timer_list oom_reaper_timer; 1584 #endif 1585 #ifdef CONFIG_VMAP_STACK 1586 struct vm_struct *stack_vm_area; 1587 #endif 1588 #ifdef CONFIG_THREAD_INFO_IN_TASK 1589 /* A live task holds one reference: */ 1590 refcount_t stack_refcount; 1591 #endif 1592 #ifdef CONFIG_LIVEPATCH 1593 int patch_state; 1594 #endif 1595 #ifdef CONFIG_SECURITY 1596 /* Used by LSM modules for access restriction: */ 1597 void *security; 1598 #endif 1599 #ifdef CONFIG_BPF_SYSCALL 1600 /* Used by BPF task local storage */ 1601 struct bpf_local_storage __rcu *bpf_storage; 1602 /* Used for BPF run context */ 1603 struct bpf_run_ctx *bpf_ctx; 1604 #endif 1605 /* Used by BPF for per-TASK xdp storage */ 1606 struct bpf_net_context *bpf_net_context; 1607 1608 #ifdef CONFIG_KSTACK_ERASE 1609 unsigned long lowest_stack; 1610 #endif 1611 #ifdef CONFIG_KSTACK_ERASE_METRICS 1612 unsigned long prev_lowest_stack; 1613 #endif 1614 1615 #ifdef CONFIG_X86_MCE 1616 void __user *mce_vaddr; 1617 __u64 mce_kflags; 1618 u64 mce_addr; 1619 __u64 mce_ripv : 1, 1620 mce_whole_page : 1, 1621 __mce_reserved : 62; 1622 struct callback_head mce_kill_me; 1623 int mce_count; 1624 #endif 1625 1626 #ifdef CONFIG_KRETPROBES 1627 struct llist_head kretprobe_instances; 1628 #endif 1629 #ifdef CONFIG_RETHOOK 1630 struct llist_head rethooks; 1631 #endif 1632 1633 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1634 /* 1635 * If L1D flush is supported on mm context switch 1636 * then we use this callback head to queue kill work 1637 * to kill tasks that are not running on SMT disabled 1638 * cores 1639 */ 1640 struct callback_head l1d_flush_kill; 1641 #endif 1642 1643 #ifdef CONFIG_RV 1644 /* 1645 * Per-task RV monitor, fixed in CONFIG_RV_PER_TASK_MONITORS. 1646 * If memory becomes a concern, we can think about a dynamic method. 1647 */ 1648 union rv_task_monitor rv[CONFIG_RV_PER_TASK_MONITORS]; 1649 #endif 1650 1651 #ifdef CONFIG_USER_EVENTS 1652 struct user_event_mm *user_event_mm; 1653 #endif 1654 1655 #ifdef CONFIG_UNWIND_USER 1656 struct unwind_task_info unwind_info; 1657 #endif 1658 1659 /* CPU-specific state of this task: */ 1660 struct thread_struct thread; 1661 1662 /* 1663 * New fields for task_struct should be added above here, so that 1664 * they are included in the randomized portion of task_struct. 1665 */ 1666 randomized_struct_fields_end 1667 } __attribute__ ((aligned (64))); 1668 1669 #ifdef CONFIG_SCHED_PROXY_EXEC 1670 DECLARE_STATIC_KEY_TRUE(__sched_proxy_exec); 1671 static inline bool sched_proxy_exec(void) 1672 { 1673 return static_branch_likely(&__sched_proxy_exec); 1674 } 1675 #else 1676 static inline bool sched_proxy_exec(void) 1677 { 1678 return false; 1679 } 1680 #endif 1681 1682 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1683 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1684 1685 static inline unsigned int __task_state_index(unsigned int tsk_state, 1686 unsigned int tsk_exit_state) 1687 { 1688 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1689 1690 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1691 1692 if ((tsk_state & TASK_IDLE) == TASK_IDLE) 1693 state = TASK_REPORT_IDLE; 1694 1695 /* 1696 * We're lying here, but rather than expose a completely new task state 1697 * to userspace, we can make this appear as if the task has gone through 1698 * a regular rt_mutex_lock() call. 1699 * Report frozen tasks as uninterruptible. 1700 */ 1701 if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN)) 1702 state = TASK_UNINTERRUPTIBLE; 1703 1704 return fls(state); 1705 } 1706 1707 static inline unsigned int task_state_index(struct task_struct *tsk) 1708 { 1709 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1710 } 1711 1712 static inline char task_index_to_char(unsigned int state) 1713 { 1714 static const char state_char[] = "RSDTtXZPI"; 1715 1716 BUILD_BUG_ON(TASK_REPORT_MAX * 2 != 1 << (sizeof(state_char) - 1)); 1717 1718 return state_char[state]; 1719 } 1720 1721 static inline char task_state_to_char(struct task_struct *tsk) 1722 { 1723 return task_index_to_char(task_state_index(tsk)); 1724 } 1725 1726 #ifdef CONFIG_ARCH_HAS_LAZY_MMU_MODE 1727 /** 1728 * __task_lazy_mmu_mode_active() - Test the lazy MMU mode state for a task. 1729 * @tsk: The task to check. 1730 * 1731 * Test whether @tsk has its lazy MMU mode state set to active (i.e. enabled 1732 * and not paused). 1733 * 1734 * This function only considers the state saved in task_struct; to test whether 1735 * current actually is in lazy MMU mode, is_lazy_mmu_mode_active() should be 1736 * used instead. 1737 * 1738 * This function is intended for architectures that implement the lazy MMU 1739 * mode; it must not be called from generic code. 1740 */ 1741 static inline bool __task_lazy_mmu_mode_active(struct task_struct *tsk) 1742 { 1743 struct lazy_mmu_state *state = &tsk->lazy_mmu_state; 1744 1745 return state->enable_count > 0 && state->pause_count == 0; 1746 } 1747 1748 /** 1749 * is_lazy_mmu_mode_active() - Test whether we are currently in lazy MMU mode. 1750 * 1751 * Test whether the current context is in lazy MMU mode. This is true if both: 1752 * 1. We are not in interrupt context 1753 * 2. Lazy MMU mode is active for the current task 1754 * 1755 * This function is intended for architectures that implement the lazy MMU 1756 * mode; it must not be called from generic code. 1757 */ 1758 static inline bool is_lazy_mmu_mode_active(void) 1759 { 1760 if (in_interrupt()) 1761 return false; 1762 1763 return __task_lazy_mmu_mode_active(current); 1764 } 1765 #endif 1766 1767 extern struct pid *cad_pid; 1768 1769 /* 1770 * Per process flags 1771 */ 1772 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1773 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1774 #define PF_EXITING 0x00000004 /* Getting shut down */ 1775 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1776 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1777 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1778 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1779 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1780 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1781 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1782 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1783 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */ 1784 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1785 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1786 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1787 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1788 #define PF_KCOMPACTD 0x00010000 /* I am kcompactd */ 1789 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1790 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */ 1791 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */ 1792 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1793 * I am cleaning dirty pages from some other bdi. */ 1794 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1795 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1796 #define PF__HOLE__00800000 0x00800000 1797 #define PF__HOLE__01000000 0x01000000 1798 #define PF__HOLE__02000000 0x02000000 1799 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1800 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1801 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning. 1802 * See memalloc_pin_save() */ 1803 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */ 1804 #define PF__HOLE__40000000 0x40000000 1805 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1806 1807 /* 1808 * Only the _current_ task can read/write to tsk->flags, but other 1809 * tasks can access tsk->flags in readonly mode for example 1810 * with tsk_used_math (like during threaded core dumping). 1811 * There is however an exception to this rule during ptrace 1812 * or during fork: the ptracer task is allowed to write to the 1813 * child->flags of its traced child (same goes for fork, the parent 1814 * can write to the child->flags), because we're guaranteed the 1815 * child is not running and in turn not changing child->flags 1816 * at the same time the parent does it. 1817 */ 1818 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1819 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1820 #define clear_used_math() clear_stopped_child_used_math(current) 1821 #define set_used_math() set_stopped_child_used_math(current) 1822 1823 #define conditional_stopped_child_used_math(condition, child) \ 1824 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1825 1826 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1827 1828 #define copy_to_stopped_child_used_math(child) \ 1829 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1830 1831 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1832 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1833 #define used_math() tsk_used_math(current) 1834 1835 static __always_inline bool is_percpu_thread(void) 1836 { 1837 return (current->flags & PF_NO_SETAFFINITY) && 1838 (current->nr_cpus_allowed == 1); 1839 } 1840 1841 static __always_inline bool is_user_task(struct task_struct *task) 1842 { 1843 return task->mm && !(task->flags & (PF_KTHREAD | PF_USER_WORKER)); 1844 } 1845 1846 /* Per-process atomic flags. */ 1847 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1848 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1849 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1850 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1851 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1852 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1853 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1854 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1855 1856 #define TASK_PFA_TEST(name, func) \ 1857 static inline bool task_##func(struct task_struct *p) \ 1858 { return test_bit(PFA_##name, &p->atomic_flags); } 1859 1860 #define TASK_PFA_SET(name, func) \ 1861 static inline void task_set_##func(struct task_struct *p) \ 1862 { set_bit(PFA_##name, &p->atomic_flags); } 1863 1864 #define TASK_PFA_CLEAR(name, func) \ 1865 static inline void task_clear_##func(struct task_struct *p) \ 1866 { clear_bit(PFA_##name, &p->atomic_flags); } 1867 1868 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1869 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1870 1871 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1872 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1873 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1874 1875 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1876 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1877 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1878 1879 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1880 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1881 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1882 1883 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1884 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1885 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1886 1887 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1888 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1889 1890 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1891 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1892 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1893 1894 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1895 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1896 1897 static inline void 1898 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1899 { 1900 current->flags &= ~flags; 1901 current->flags |= orig_flags & flags; 1902 } 1903 1904 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1905 extern int task_can_attach(struct task_struct *p); 1906 extern int dl_bw_alloc(int cpu, u64 dl_bw); 1907 extern void dl_bw_free(int cpu, u64 dl_bw); 1908 1909 /* set_cpus_allowed_force() - consider using set_cpus_allowed_ptr() instead */ 1910 extern void set_cpus_allowed_force(struct task_struct *p, const struct cpumask *new_mask); 1911 1912 /** 1913 * set_cpus_allowed_ptr - set CPU affinity mask of a task 1914 * @p: the task 1915 * @new_mask: CPU affinity mask 1916 * 1917 * Return: zero if successful, or a negative error code 1918 */ 1919 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1920 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1921 extern void release_user_cpus_ptr(struct task_struct *p); 1922 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1923 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1924 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1925 1926 extern int yield_to(struct task_struct *p, bool preempt); 1927 extern void set_user_nice(struct task_struct *p, long nice); 1928 extern int task_prio(const struct task_struct *p); 1929 1930 /** 1931 * task_nice - return the nice value of a given task. 1932 * @p: the task in question. 1933 * 1934 * Return: The nice value [ -20 ... 0 ... 19 ]. 1935 */ 1936 static inline int task_nice(const struct task_struct *p) 1937 { 1938 return PRIO_TO_NICE((p)->static_prio); 1939 } 1940 1941 extern int can_nice(const struct task_struct *p, const int nice); 1942 extern int task_curr(const struct task_struct *p); 1943 extern int idle_cpu(int cpu); 1944 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1945 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1946 extern void sched_set_fifo(struct task_struct *p); 1947 extern void sched_set_fifo_low(struct task_struct *p); 1948 extern void sched_set_fifo_secondary(struct task_struct *p); 1949 extern void sched_set_normal(struct task_struct *p, int nice); 1950 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1951 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1952 extern struct task_struct *idle_task(int cpu); 1953 1954 /** 1955 * is_idle_task - is the specified task an idle task? 1956 * @p: the task in question. 1957 * 1958 * Return: 1 if @p is an idle task. 0 otherwise. 1959 */ 1960 static __always_inline bool is_idle_task(const struct task_struct *p) 1961 { 1962 return !!(p->flags & PF_IDLE); 1963 } 1964 1965 extern struct task_struct *curr_task(int cpu); 1966 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1967 1968 void yield(void); 1969 1970 union thread_union { 1971 struct task_struct task; 1972 #ifndef CONFIG_THREAD_INFO_IN_TASK 1973 struct thread_info thread_info; 1974 #endif 1975 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1976 }; 1977 1978 #ifndef CONFIG_THREAD_INFO_IN_TASK 1979 extern struct thread_info init_thread_info; 1980 #endif 1981 1982 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1983 1984 #ifdef CONFIG_THREAD_INFO_IN_TASK 1985 # define task_thread_info(task) (&(task)->thread_info) 1986 #else 1987 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1988 #endif 1989 1990 /* 1991 * find a task by one of its numerical ids 1992 * 1993 * find_task_by_pid_ns(): 1994 * finds a task by its pid in the specified namespace 1995 * find_task_by_vpid(): 1996 * finds a task by its virtual pid 1997 * 1998 * see also find_vpid() etc in include/linux/pid.h 1999 */ 2000 2001 extern struct task_struct *find_task_by_vpid(pid_t nr); 2002 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 2003 2004 /* 2005 * find a task by its virtual pid and get the task struct 2006 */ 2007 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 2008 2009 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 2010 extern int wake_up_process(struct task_struct *tsk); 2011 extern void wake_up_new_task(struct task_struct *tsk); 2012 2013 extern void kick_process(struct task_struct *tsk); 2014 2015 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 2016 #define set_task_comm(tsk, from) ({ \ 2017 BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \ 2018 __set_task_comm(tsk, from, false); \ 2019 }) 2020 2021 /* 2022 * - Why not use task_lock()? 2023 * User space can randomly change their names anyway, so locking for readers 2024 * doesn't make sense. For writers, locking is probably necessary, as a race 2025 * condition could lead to long-term mixed results. 2026 * The strscpy_pad() in __set_task_comm() can ensure that the task comm is 2027 * always NUL-terminated and zero-padded. Therefore the race condition between 2028 * reader and writer is not an issue. 2029 * 2030 * - BUILD_BUG_ON() can help prevent the buf from being truncated. 2031 * Since the callers don't perform any return value checks, this safeguard is 2032 * necessary. 2033 */ 2034 #define get_task_comm(buf, tsk) ({ \ 2035 BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \ 2036 strscpy_pad(buf, (tsk)->comm); \ 2037 buf; \ 2038 }) 2039 2040 static __always_inline void scheduler_ipi(void) 2041 { 2042 /* 2043 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 2044 * TIF_NEED_RESCHED remotely (for the first time) will also send 2045 * this IPI. 2046 */ 2047 preempt_fold_need_resched(); 2048 } 2049 2050 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 2051 2052 /* 2053 * Set thread flags in other task's structures. 2054 * See asm/thread_info.h for TIF_xxxx flags available: 2055 */ 2056 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2057 { 2058 set_ti_thread_flag(task_thread_info(tsk), flag); 2059 } 2060 2061 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2062 { 2063 clear_ti_thread_flag(task_thread_info(tsk), flag); 2064 } 2065 2066 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2067 bool value) 2068 { 2069 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2070 } 2071 2072 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2073 { 2074 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2075 } 2076 2077 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2078 { 2079 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2080 } 2081 2082 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2083 { 2084 return test_ti_thread_flag(task_thread_info(tsk), flag); 2085 } 2086 2087 static inline void set_tsk_need_resched(struct task_struct *tsk) 2088 { 2089 if (tracepoint_enabled(sched_set_need_resched_tp) && 2090 !test_tsk_thread_flag(tsk, TIF_NEED_RESCHED)) 2091 __trace_set_need_resched(tsk, TIF_NEED_RESCHED); 2092 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2093 } 2094 2095 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2096 { 2097 atomic_long_andnot(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY, 2098 (atomic_long_t *)&task_thread_info(tsk)->flags); 2099 } 2100 2101 static inline int test_tsk_need_resched(struct task_struct *tsk) 2102 { 2103 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2104 } 2105 2106 static inline void set_need_resched_current(void) 2107 { 2108 lockdep_assert_irqs_disabled(); 2109 set_tsk_need_resched(current); 2110 set_preempt_need_resched(); 2111 } 2112 2113 /* 2114 * cond_resched() and cond_resched_lock(): latency reduction via 2115 * explicit rescheduling in places that are safe. The return 2116 * value indicates whether a reschedule was done in fact. 2117 * cond_resched_lock() will drop the spinlock before scheduling, 2118 */ 2119 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2120 extern int __cond_resched(void); 2121 2122 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2123 2124 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2125 2126 static __always_inline int _cond_resched(void) 2127 { 2128 return static_call_mod(cond_resched)(); 2129 } 2130 2131 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2132 2133 extern int dynamic_cond_resched(void); 2134 2135 static __always_inline int _cond_resched(void) 2136 { 2137 return dynamic_cond_resched(); 2138 } 2139 2140 #else /* !CONFIG_PREEMPTION */ 2141 2142 static inline int _cond_resched(void) 2143 { 2144 return __cond_resched(); 2145 } 2146 2147 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2148 2149 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2150 2151 static inline int _cond_resched(void) 2152 { 2153 return 0; 2154 } 2155 2156 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2157 2158 #define cond_resched() ({ \ 2159 __might_resched(__FILE__, __LINE__, 0); \ 2160 _cond_resched(); \ 2161 }) 2162 2163 extern int __cond_resched_lock(spinlock_t *lock) __must_hold(lock); 2164 extern int __cond_resched_rwlock_read(rwlock_t *lock) __must_hold_shared(lock); 2165 extern int __cond_resched_rwlock_write(rwlock_t *lock) __must_hold(lock); 2166 2167 #define MIGHT_RESCHED_RCU_SHIFT 8 2168 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2169 2170 #ifndef CONFIG_PREEMPT_RT 2171 /* 2172 * Non RT kernels have an elevated preempt count due to the held lock, 2173 * but are not allowed to be inside a RCU read side critical section 2174 */ 2175 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2176 #else 2177 /* 2178 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2179 * cond_resched*lock() has to take that into account because it checks for 2180 * preempt_count() and rcu_preempt_depth(). 2181 */ 2182 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2183 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2184 #endif 2185 2186 #define cond_resched_lock(lock) ({ \ 2187 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2188 __cond_resched_lock(lock); \ 2189 }) 2190 2191 #define cond_resched_rwlock_read(lock) ({ \ 2192 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2193 __cond_resched_rwlock_read(lock); \ 2194 }) 2195 2196 #define cond_resched_rwlock_write(lock) ({ \ 2197 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2198 __cond_resched_rwlock_write(lock); \ 2199 }) 2200 2201 #ifndef CONFIG_PREEMPT_RT 2202 2203 static inline struct mutex *__get_task_blocked_on(struct task_struct *p) 2204 { 2205 lockdep_assert_held_once(&p->blocked_lock); 2206 return p->blocked_on; 2207 } 2208 2209 static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m) 2210 { 2211 WARN_ON_ONCE(!m); 2212 /* The task should only be setting itself as blocked */ 2213 WARN_ON_ONCE(p != current); 2214 /* Currently we serialize blocked_on under the task::blocked_lock */ 2215 lockdep_assert_held_once(&p->blocked_lock); 2216 /* 2217 * Check ensure we don't overwrite existing mutex value 2218 * with a different mutex. Note, setting it to the same 2219 * lock repeatedly is ok. 2220 */ 2221 WARN_ON_ONCE(p->blocked_on && p->blocked_on != m); 2222 p->blocked_on = m; 2223 } 2224 2225 static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m) 2226 { 2227 /* Currently we serialize blocked_on under the task::blocked_lock */ 2228 lockdep_assert_held_once(&p->blocked_lock); 2229 /* 2230 * There may be cases where we re-clear already cleared 2231 * blocked_on relationships, but make sure we are not 2232 * clearing the relationship with a different lock. 2233 */ 2234 WARN_ON_ONCE(m && p->blocked_on && p->blocked_on != m); 2235 p->blocked_on = NULL; 2236 } 2237 2238 static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m) 2239 { 2240 guard(raw_spinlock_irqsave)(&p->blocked_lock); 2241 __clear_task_blocked_on(p, m); 2242 } 2243 #else 2244 static inline void __clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m) 2245 { 2246 } 2247 2248 static inline void clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m) 2249 { 2250 } 2251 #endif /* !CONFIG_PREEMPT_RT */ 2252 2253 static __always_inline bool need_resched(void) 2254 { 2255 return unlikely(tif_need_resched()); 2256 } 2257 2258 /* 2259 * Wrappers for p->thread_info->cpu access. No-op on UP. 2260 */ 2261 #ifdef CONFIG_SMP 2262 2263 static inline unsigned int task_cpu(const struct task_struct *p) 2264 { 2265 return READ_ONCE(task_thread_info(p)->cpu); 2266 } 2267 2268 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2269 2270 #else 2271 2272 static inline unsigned int task_cpu(const struct task_struct *p) 2273 { 2274 return 0; 2275 } 2276 2277 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2278 { 2279 } 2280 2281 #endif /* CONFIG_SMP */ 2282 2283 static inline bool task_is_runnable(struct task_struct *p) 2284 { 2285 return p->on_rq && !p->se.sched_delayed; 2286 } 2287 2288 extern bool sched_task_on_rq(struct task_struct *p); 2289 extern unsigned long get_wchan(struct task_struct *p); 2290 extern struct task_struct *cpu_curr_snapshot(int cpu); 2291 2292 /* 2293 * In order to reduce various lock holder preemption latencies provide an 2294 * interface to see if a vCPU is currently running or not. 2295 * 2296 * This allows us to terminate optimistic spin loops and block, analogous to 2297 * the native optimistic spin heuristic of testing if the lock owner task is 2298 * running or not. 2299 */ 2300 #ifndef vcpu_is_preempted 2301 static inline bool vcpu_is_preempted(int cpu) 2302 { 2303 return false; 2304 } 2305 #endif 2306 2307 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2308 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2309 2310 #ifndef TASK_SIZE_OF 2311 #define TASK_SIZE_OF(tsk) TASK_SIZE 2312 #endif 2313 2314 static inline bool owner_on_cpu(struct task_struct *owner) 2315 { 2316 /* 2317 * As lock holder preemption issue, we both skip spinning if 2318 * task is not on cpu or its cpu is preempted 2319 */ 2320 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2321 } 2322 2323 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2324 unsigned long sched_cpu_util(int cpu); 2325 2326 #ifdef CONFIG_SCHED_CORE 2327 extern void sched_core_free(struct task_struct *tsk); 2328 extern void sched_core_fork(struct task_struct *p); 2329 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2330 unsigned long uaddr); 2331 extern int sched_core_idle_cpu(int cpu); 2332 #else 2333 static inline void sched_core_free(struct task_struct *tsk) { } 2334 static inline void sched_core_fork(struct task_struct *p) { } 2335 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); } 2336 #endif 2337 2338 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2339 2340 #ifdef CONFIG_MEM_ALLOC_PROFILING 2341 static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag) 2342 { 2343 swap(current->alloc_tag, tag); 2344 return tag; 2345 } 2346 2347 static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old) 2348 { 2349 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG 2350 WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n"); 2351 #endif 2352 current->alloc_tag = old; 2353 } 2354 #else 2355 #define alloc_tag_save(_tag) NULL 2356 #define alloc_tag_restore(_tag, _old) do {} while (0) 2357 #endif 2358 2359 /* Avoids recursive inclusion hell */ 2360 #ifdef CONFIG_SCHED_MM_CID 2361 void sched_mm_cid_before_execve(struct task_struct *t); 2362 void sched_mm_cid_after_execve(struct task_struct *t); 2363 void sched_mm_cid_exit(struct task_struct *t); 2364 static __always_inline int task_mm_cid(struct task_struct *t) 2365 { 2366 return t->mm_cid.cid & ~(MM_CID_ONCPU | MM_CID_TRANSIT); 2367 } 2368 #else 2369 static inline void sched_mm_cid_before_execve(struct task_struct *t) { } 2370 static inline void sched_mm_cid_after_execve(struct task_struct *t) { } 2371 static inline void sched_mm_cid_exit(struct task_struct *t) { } 2372 static __always_inline int task_mm_cid(struct task_struct *t) 2373 { 2374 /* 2375 * Use the processor id as a fall-back when the mm cid feature is 2376 * disabled. This provides functional per-cpu data structure accesses 2377 * in user-space, althrough it won't provide the memory usage benefits. 2378 */ 2379 return task_cpu(t); 2380 } 2381 #endif 2382 2383 #ifdef CONFIG_SCHED_CACHE 2384 2385 struct sched_cache_time { 2386 u64 runtime; 2387 unsigned long epoch; 2388 }; 2389 2390 struct sched_cache_stat { 2391 struct sched_cache_time __percpu *pcpu_sched; 2392 raw_spinlock_t lock; 2393 unsigned long epoch; 2394 u64 nr_running_avg; 2395 unsigned long next_scan; 2396 unsigned long footprint; 2397 int cpu; 2398 } ____cacheline_aligned_in_smp; 2399 2400 #else 2401 2402 struct sched_cache_stat { }; 2403 2404 #endif 2405 2406 #ifndef MODULE 2407 #ifndef COMPILE_OFFSETS 2408 2409 extern void ___migrate_enable(void); 2410 2411 struct rq; 2412 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 2413 2414 /* 2415 * The "struct rq" is not available here, so we can't access the 2416 * "runqueues" with this_cpu_ptr(), as the compilation will fail in 2417 * this_cpu_ptr() -> raw_cpu_ptr() -> __verify_pcpu_ptr(): 2418 * typeof((ptr) + 0) 2419 * 2420 * So use arch_raw_cpu_ptr()/PERCPU_PTR() directly here. 2421 */ 2422 #ifdef CONFIG_SMP 2423 #define this_rq_raw() arch_raw_cpu_ptr(&runqueues) 2424 #else 2425 #define this_rq_raw() PERCPU_PTR(&runqueues) 2426 #endif 2427 #define this_rq_pinned() (*(unsigned int *)((void *)this_rq_raw() + RQ_nr_pinned)) 2428 2429 static inline void __migrate_enable(void) 2430 { 2431 struct task_struct *p = current; 2432 2433 #ifdef CONFIG_DEBUG_PREEMPT 2434 /* 2435 * Check both overflow from migrate_disable() and superfluous 2436 * migrate_enable(). 2437 */ 2438 if (WARN_ON_ONCE((s16)p->migration_disabled <= 0)) 2439 return; 2440 #endif 2441 2442 if (p->migration_disabled > 1) { 2443 p->migration_disabled--; 2444 return; 2445 } 2446 2447 /* 2448 * Ensure stop_task runs either before or after this, and that 2449 * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule(). 2450 */ 2451 guard(preempt)(); 2452 if (unlikely(p->cpus_ptr != &p->cpus_mask)) 2453 ___migrate_enable(); 2454 /* 2455 * Mustn't clear migration_disabled() until cpus_ptr points back at the 2456 * regular cpus_mask, otherwise things that race (eg. 2457 * select_fallback_rq) get confused. 2458 */ 2459 barrier(); 2460 p->migration_disabled = 0; 2461 this_rq_pinned()--; 2462 } 2463 2464 static inline void __migrate_disable(void) 2465 { 2466 struct task_struct *p = current; 2467 2468 if (p->migration_disabled) { 2469 #ifdef CONFIG_DEBUG_PREEMPT 2470 /* 2471 *Warn about overflow half-way through the range. 2472 */ 2473 WARN_ON_ONCE((s16)p->migration_disabled < 0); 2474 #endif 2475 p->migration_disabled++; 2476 return; 2477 } 2478 2479 guard(preempt)(); 2480 this_rq_pinned()++; 2481 p->migration_disabled = 1; 2482 } 2483 #else /* !COMPILE_OFFSETS */ 2484 static inline void __migrate_disable(void) { } 2485 static inline void __migrate_enable(void) { } 2486 #endif /* !COMPILE_OFFSETS */ 2487 2488 /* 2489 * So that it is possible to not export the runqueues variable, define and 2490 * export migrate_enable/migrate_disable in kernel/sched/core.c too, and use 2491 * them for the modules. The macro "INSTANTIATE_EXPORTED_MIGRATE_DISABLE" will 2492 * be defined in kernel/sched/core.c. 2493 */ 2494 #ifndef INSTANTIATE_EXPORTED_MIGRATE_DISABLE 2495 static __always_inline void migrate_disable(void) 2496 { 2497 __migrate_disable(); 2498 } 2499 2500 static __always_inline void migrate_enable(void) 2501 { 2502 __migrate_enable(); 2503 } 2504 #else /* INSTANTIATE_EXPORTED_MIGRATE_DISABLE */ 2505 extern void migrate_disable(void); 2506 extern void migrate_enable(void); 2507 #endif /* INSTANTIATE_EXPORTED_MIGRATE_DISABLE */ 2508 2509 #else /* MODULE */ 2510 extern void migrate_disable(void); 2511 extern void migrate_enable(void); 2512 #endif /* MODULE */ 2513 2514 DEFINE_LOCK_GUARD_0(migrate, migrate_disable(), migrate_enable()) 2515 2516 #endif 2517