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 14 #include <linux/pid.h> 15 #include <linux/sem.h> 16 #include <linux/shm.h> 17 #include <linux/kcov.h> 18 #include <linux/mutex.h> 19 #include <linux/plist.h> 20 #include <linux/hrtimer.h> 21 #include <linux/seccomp.h> 22 #include <linux/nodemask.h> 23 #include <linux/rcupdate.h> 24 #include <linux/resource.h> 25 #include <linux/latencytop.h> 26 #include <linux/sched/prio.h> 27 #include <linux/signal_types.h> 28 #include <linux/mm_types_task.h> 29 #include <linux/task_io_accounting.h> 30 31 /* task_struct member predeclarations (sorted alphabetically): */ 32 struct audit_context; 33 struct backing_dev_info; 34 struct bio_list; 35 struct blk_plug; 36 struct cfs_rq; 37 struct fs_struct; 38 struct futex_pi_state; 39 struct io_context; 40 struct mempolicy; 41 struct nameidata; 42 struct nsproxy; 43 struct perf_event_context; 44 struct pid_namespace; 45 struct pipe_inode_info; 46 struct rcu_node; 47 struct reclaim_state; 48 struct robust_list_head; 49 struct sched_attr; 50 struct sched_param; 51 struct seq_file; 52 struct sighand_struct; 53 struct signal_struct; 54 struct task_delay_info; 55 struct task_group; 56 57 /* 58 * Task state bitmask. NOTE! These bits are also 59 * encoded in fs/proc/array.c: get_task_state(). 60 * 61 * We have two separate sets of flags: task->state 62 * is about runnability, while task->exit_state are 63 * about the task exiting. Confusing, but this way 64 * modifying one set can't modify the other one by 65 * mistake. 66 */ 67 68 /* Used in tsk->state: */ 69 #define TASK_RUNNING 0x0000 70 #define TASK_INTERRUPTIBLE 0x0001 71 #define TASK_UNINTERRUPTIBLE 0x0002 72 #define __TASK_STOPPED 0x0004 73 #define __TASK_TRACED 0x0008 74 /* Used in tsk->exit_state: */ 75 #define EXIT_DEAD 0x0010 76 #define EXIT_ZOMBIE 0x0020 77 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 78 /* Used in tsk->state again: */ 79 #define TASK_PARKED 0x0040 80 #define TASK_DEAD 0x0080 81 #define TASK_WAKEKILL 0x0100 82 #define TASK_WAKING 0x0200 83 #define TASK_NOLOAD 0x0400 84 #define TASK_NEW 0x0800 85 #define TASK_STATE_MAX 0x1000 86 87 /* Convenience macros for the sake of set_current_state: */ 88 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 89 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 90 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) 91 92 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 93 94 /* Convenience macros for the sake of wake_up(): */ 95 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 96 #define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED) 97 98 /* get_task_state(): */ 99 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 100 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 101 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 102 TASK_PARKED) 103 104 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0) 105 106 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0) 107 108 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) 109 110 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \ 111 (task->flags & PF_FROZEN) == 0 && \ 112 (task->state & TASK_NOLOAD) == 0) 113 114 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 115 116 #define __set_current_state(state_value) \ 117 do { \ 118 current->task_state_change = _THIS_IP_; \ 119 current->state = (state_value); \ 120 } while (0) 121 #define set_current_state(state_value) \ 122 do { \ 123 current->task_state_change = _THIS_IP_; \ 124 smp_store_mb(current->state, (state_value)); \ 125 } while (0) 126 127 #else 128 /* 129 * set_current_state() includes a barrier so that the write of current->state 130 * is correctly serialised wrt the caller's subsequent test of whether to 131 * actually sleep: 132 * 133 * for (;;) { 134 * set_current_state(TASK_UNINTERRUPTIBLE); 135 * if (!need_sleep) 136 * break; 137 * 138 * schedule(); 139 * } 140 * __set_current_state(TASK_RUNNING); 141 * 142 * If the caller does not need such serialisation (because, for instance, the 143 * condition test and condition change and wakeup are under the same lock) then 144 * use __set_current_state(). 145 * 146 * The above is typically ordered against the wakeup, which does: 147 * 148 * need_sleep = false; 149 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 150 * 151 * Where wake_up_state() (and all other wakeup primitives) imply enough 152 * barriers to order the store of the variable against wakeup. 153 * 154 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 155 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 156 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 157 * 158 * This is obviously fine, since they both store the exact same value. 159 * 160 * Also see the comments of try_to_wake_up(). 161 */ 162 #define __set_current_state(state_value) do { current->state = (state_value); } while (0) 163 #define set_current_state(state_value) smp_store_mb(current->state, (state_value)) 164 #endif 165 166 /* Task command name length: */ 167 #define TASK_COMM_LEN 16 168 169 extern void scheduler_tick(void); 170 171 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 172 173 extern long schedule_timeout(long timeout); 174 extern long schedule_timeout_interruptible(long timeout); 175 extern long schedule_timeout_killable(long timeout); 176 extern long schedule_timeout_uninterruptible(long timeout); 177 extern long schedule_timeout_idle(long timeout); 178 asmlinkage void schedule(void); 179 extern void schedule_preempt_disabled(void); 180 181 extern int __must_check io_schedule_prepare(void); 182 extern void io_schedule_finish(int token); 183 extern long io_schedule_timeout(long timeout); 184 extern void io_schedule(void); 185 186 /** 187 * struct prev_cputime - snapshot of system and user cputime 188 * @utime: time spent in user mode 189 * @stime: time spent in system mode 190 * @lock: protects the above two fields 191 * 192 * Stores previous user/system time values such that we can guarantee 193 * monotonicity. 194 */ 195 struct prev_cputime { 196 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 197 u64 utime; 198 u64 stime; 199 raw_spinlock_t lock; 200 #endif 201 }; 202 203 /** 204 * struct task_cputime - collected CPU time counts 205 * @utime: time spent in user mode, in nanoseconds 206 * @stime: time spent in kernel mode, in nanoseconds 207 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds 208 * 209 * This structure groups together three kinds of CPU time that are tracked for 210 * threads and thread groups. Most things considering CPU time want to group 211 * these counts together and treat all three of them in parallel. 212 */ 213 struct task_cputime { 214 u64 utime; 215 u64 stime; 216 unsigned long long sum_exec_runtime; 217 }; 218 219 /* Alternate field names when used on cache expirations: */ 220 #define virt_exp utime 221 #define prof_exp stime 222 #define sched_exp sum_exec_runtime 223 224 enum vtime_state { 225 /* Task is sleeping or running in a CPU with VTIME inactive: */ 226 VTIME_INACTIVE = 0, 227 /* Task runs in userspace in a CPU with VTIME active: */ 228 VTIME_USER, 229 /* Task runs in kernelspace in a CPU with VTIME active: */ 230 VTIME_SYS, 231 }; 232 233 struct vtime { 234 seqcount_t seqcount; 235 unsigned long long starttime; 236 enum vtime_state state; 237 u64 utime; 238 u64 stime; 239 u64 gtime; 240 }; 241 242 struct sched_info { 243 #ifdef CONFIG_SCHED_INFO 244 /* Cumulative counters: */ 245 246 /* # of times we have run on this CPU: */ 247 unsigned long pcount; 248 249 /* Time spent waiting on a runqueue: */ 250 unsigned long long run_delay; 251 252 /* Timestamps: */ 253 254 /* When did we last run on a CPU? */ 255 unsigned long long last_arrival; 256 257 /* When were we last queued to run? */ 258 unsigned long long last_queued; 259 260 #endif /* CONFIG_SCHED_INFO */ 261 }; 262 263 /* 264 * Integer metrics need fixed point arithmetic, e.g., sched/fair 265 * has a few: load, load_avg, util_avg, freq, and capacity. 266 * 267 * We define a basic fixed point arithmetic range, and then formalize 268 * all these metrics based on that basic range. 269 */ 270 # define SCHED_FIXEDPOINT_SHIFT 10 271 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 272 273 struct load_weight { 274 unsigned long weight; 275 u32 inv_weight; 276 }; 277 278 /* 279 * The load_avg/util_avg accumulates an infinite geometric series 280 * (see __update_load_avg() in kernel/sched/fair.c). 281 * 282 * [load_avg definition] 283 * 284 * load_avg = runnable% * scale_load_down(load) 285 * 286 * where runnable% is the time ratio that a sched_entity is runnable. 287 * For cfs_rq, it is the aggregated load_avg of all runnable and 288 * blocked sched_entities. 289 * 290 * load_avg may also take frequency scaling into account: 291 * 292 * load_avg = runnable% * scale_load_down(load) * freq% 293 * 294 * where freq% is the CPU frequency normalized to the highest frequency. 295 * 296 * [util_avg definition] 297 * 298 * util_avg = running% * SCHED_CAPACITY_SCALE 299 * 300 * where running% is the time ratio that a sched_entity is running on 301 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable 302 * and blocked sched_entities. 303 * 304 * util_avg may also factor frequency scaling and CPU capacity scaling: 305 * 306 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity% 307 * 308 * where freq% is the same as above, and capacity% is the CPU capacity 309 * normalized to the greatest capacity (due to uarch differences, etc). 310 * 311 * N.B., the above ratios (runnable%, running%, freq%, and capacity%) 312 * themselves are in the range of [0, 1]. To do fixed point arithmetics, 313 * we therefore scale them to as large a range as necessary. This is for 314 * example reflected by util_avg's SCHED_CAPACITY_SCALE. 315 * 316 * [Overflow issue] 317 * 318 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 319 * with the highest load (=88761), always runnable on a single cfs_rq, 320 * and should not overflow as the number already hits PID_MAX_LIMIT. 321 * 322 * For all other cases (including 32-bit kernels), struct load_weight's 323 * weight will overflow first before we do, because: 324 * 325 * Max(load_avg) <= Max(load.weight) 326 * 327 * Then it is the load_weight's responsibility to consider overflow 328 * issues. 329 */ 330 struct sched_avg { 331 u64 last_update_time; 332 u64 load_sum; 333 u64 runnable_load_sum; 334 u32 util_sum; 335 u32 period_contrib; 336 unsigned long load_avg; 337 unsigned long runnable_load_avg; 338 unsigned long util_avg; 339 }; 340 341 struct sched_statistics { 342 #ifdef CONFIG_SCHEDSTATS 343 u64 wait_start; 344 u64 wait_max; 345 u64 wait_count; 346 u64 wait_sum; 347 u64 iowait_count; 348 u64 iowait_sum; 349 350 u64 sleep_start; 351 u64 sleep_max; 352 s64 sum_sleep_runtime; 353 354 u64 block_start; 355 u64 block_max; 356 u64 exec_max; 357 u64 slice_max; 358 359 u64 nr_migrations_cold; 360 u64 nr_failed_migrations_affine; 361 u64 nr_failed_migrations_running; 362 u64 nr_failed_migrations_hot; 363 u64 nr_forced_migrations; 364 365 u64 nr_wakeups; 366 u64 nr_wakeups_sync; 367 u64 nr_wakeups_migrate; 368 u64 nr_wakeups_local; 369 u64 nr_wakeups_remote; 370 u64 nr_wakeups_affine; 371 u64 nr_wakeups_affine_attempts; 372 u64 nr_wakeups_passive; 373 u64 nr_wakeups_idle; 374 #endif 375 }; 376 377 struct sched_entity { 378 /* For load-balancing: */ 379 struct load_weight load; 380 unsigned long runnable_weight; 381 struct rb_node run_node; 382 struct list_head group_node; 383 unsigned int on_rq; 384 385 u64 exec_start; 386 u64 sum_exec_runtime; 387 u64 vruntime; 388 u64 prev_sum_exec_runtime; 389 390 u64 nr_migrations; 391 392 struct sched_statistics statistics; 393 394 #ifdef CONFIG_FAIR_GROUP_SCHED 395 int depth; 396 struct sched_entity *parent; 397 /* rq on which this entity is (to be) queued: */ 398 struct cfs_rq *cfs_rq; 399 /* rq "owned" by this entity/group: */ 400 struct cfs_rq *my_q; 401 #endif 402 403 #ifdef CONFIG_SMP 404 /* 405 * Per entity load average tracking. 406 * 407 * Put into separate cache line so it does not 408 * collide with read-mostly values above. 409 */ 410 struct sched_avg avg ____cacheline_aligned_in_smp; 411 #endif 412 }; 413 414 struct sched_rt_entity { 415 struct list_head run_list; 416 unsigned long timeout; 417 unsigned long watchdog_stamp; 418 unsigned int time_slice; 419 unsigned short on_rq; 420 unsigned short on_list; 421 422 struct sched_rt_entity *back; 423 #ifdef CONFIG_RT_GROUP_SCHED 424 struct sched_rt_entity *parent; 425 /* rq on which this entity is (to be) queued: */ 426 struct rt_rq *rt_rq; 427 /* rq "owned" by this entity/group: */ 428 struct rt_rq *my_q; 429 #endif 430 } __randomize_layout; 431 432 struct sched_dl_entity { 433 struct rb_node rb_node; 434 435 /* 436 * Original scheduling parameters. Copied here from sched_attr 437 * during sched_setattr(), they will remain the same until 438 * the next sched_setattr(). 439 */ 440 u64 dl_runtime; /* Maximum runtime for each instance */ 441 u64 dl_deadline; /* Relative deadline of each instance */ 442 u64 dl_period; /* Separation of two instances (period) */ 443 u64 dl_bw; /* dl_runtime / dl_period */ 444 u64 dl_density; /* dl_runtime / dl_deadline */ 445 446 /* 447 * Actual scheduling parameters. Initialized with the values above, 448 * they are continously updated during task execution. Note that 449 * the remaining runtime could be < 0 in case we are in overrun. 450 */ 451 s64 runtime; /* Remaining runtime for this instance */ 452 u64 deadline; /* Absolute deadline for this instance */ 453 unsigned int flags; /* Specifying the scheduler behaviour */ 454 455 /* 456 * Some bool flags: 457 * 458 * @dl_throttled tells if we exhausted the runtime. If so, the 459 * task has to wait for a replenishment to be performed at the 460 * next firing of dl_timer. 461 * 462 * @dl_boosted tells if we are boosted due to DI. If so we are 463 * outside bandwidth enforcement mechanism (but only until we 464 * exit the critical section); 465 * 466 * @dl_yielded tells if task gave up the CPU before consuming 467 * all its available runtime during the last job. 468 * 469 * @dl_non_contending tells if the task is inactive while still 470 * contributing to the active utilization. In other words, it 471 * indicates if the inactive timer has been armed and its handler 472 * has not been executed yet. This flag is useful to avoid race 473 * conditions between the inactive timer handler and the wakeup 474 * code. 475 */ 476 int dl_throttled : 1; 477 int dl_boosted : 1; 478 int dl_yielded : 1; 479 int dl_non_contending : 1; 480 481 /* 482 * Bandwidth enforcement timer. Each -deadline task has its 483 * own bandwidth to be enforced, thus we need one timer per task. 484 */ 485 struct hrtimer dl_timer; 486 487 /* 488 * Inactive timer, responsible for decreasing the active utilization 489 * at the "0-lag time". When a -deadline task blocks, it contributes 490 * to GRUB's active utilization until the "0-lag time", hence a 491 * timer is needed to decrease the active utilization at the correct 492 * time. 493 */ 494 struct hrtimer inactive_timer; 495 }; 496 497 union rcu_special { 498 struct { 499 u8 blocked; 500 u8 need_qs; 501 u8 exp_need_qs; 502 503 /* Otherwise the compiler can store garbage here: */ 504 u8 pad; 505 } b; /* Bits. */ 506 u32 s; /* Set of bits. */ 507 }; 508 509 enum perf_event_task_context { 510 perf_invalid_context = -1, 511 perf_hw_context = 0, 512 perf_sw_context, 513 perf_nr_task_contexts, 514 }; 515 516 struct wake_q_node { 517 struct wake_q_node *next; 518 }; 519 520 struct task_struct { 521 #ifdef CONFIG_THREAD_INFO_IN_TASK 522 /* 523 * For reasons of header soup (see current_thread_info()), this 524 * must be the first element of task_struct. 525 */ 526 struct thread_info thread_info; 527 #endif 528 /* -1 unrunnable, 0 runnable, >0 stopped: */ 529 volatile long state; 530 531 /* 532 * This begins the randomizable portion of task_struct. Only 533 * scheduling-critical items should be added above here. 534 */ 535 randomized_struct_fields_start 536 537 void *stack; 538 atomic_t usage; 539 /* Per task flags (PF_*), defined further below: */ 540 unsigned int flags; 541 unsigned int ptrace; 542 543 #ifdef CONFIG_SMP 544 struct llist_node wake_entry; 545 int on_cpu; 546 #ifdef CONFIG_THREAD_INFO_IN_TASK 547 /* Current CPU: */ 548 unsigned int cpu; 549 #endif 550 unsigned int wakee_flips; 551 unsigned long wakee_flip_decay_ts; 552 struct task_struct *last_wakee; 553 554 int wake_cpu; 555 #endif 556 int on_rq; 557 558 int prio; 559 int static_prio; 560 int normal_prio; 561 unsigned int rt_priority; 562 563 const struct sched_class *sched_class; 564 struct sched_entity se; 565 struct sched_rt_entity rt; 566 #ifdef CONFIG_CGROUP_SCHED 567 struct task_group *sched_task_group; 568 #endif 569 struct sched_dl_entity dl; 570 571 #ifdef CONFIG_PREEMPT_NOTIFIERS 572 /* List of struct preempt_notifier: */ 573 struct hlist_head preempt_notifiers; 574 #endif 575 576 #ifdef CONFIG_BLK_DEV_IO_TRACE 577 unsigned int btrace_seq; 578 #endif 579 580 unsigned int policy; 581 int nr_cpus_allowed; 582 cpumask_t cpus_allowed; 583 584 #ifdef CONFIG_PREEMPT_RCU 585 int rcu_read_lock_nesting; 586 union rcu_special rcu_read_unlock_special; 587 struct list_head rcu_node_entry; 588 struct rcu_node *rcu_blocked_node; 589 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 590 591 #ifdef CONFIG_TASKS_RCU 592 unsigned long rcu_tasks_nvcsw; 593 u8 rcu_tasks_holdout; 594 u8 rcu_tasks_idx; 595 int rcu_tasks_idle_cpu; 596 struct list_head rcu_tasks_holdout_list; 597 #endif /* #ifdef CONFIG_TASKS_RCU */ 598 599 struct sched_info sched_info; 600 601 struct list_head tasks; 602 #ifdef CONFIG_SMP 603 struct plist_node pushable_tasks; 604 struct rb_node pushable_dl_tasks; 605 #endif 606 607 struct mm_struct *mm; 608 struct mm_struct *active_mm; 609 610 /* Per-thread vma caching: */ 611 struct vmacache vmacache; 612 613 #ifdef SPLIT_RSS_COUNTING 614 struct task_rss_stat rss_stat; 615 #endif 616 int exit_state; 617 int exit_code; 618 int exit_signal; 619 /* The signal sent when the parent dies: */ 620 int pdeath_signal; 621 /* JOBCTL_*, siglock protected: */ 622 unsigned long jobctl; 623 624 /* Used for emulating ABI behavior of previous Linux versions: */ 625 unsigned int personality; 626 627 /* Scheduler bits, serialized by scheduler locks: */ 628 unsigned sched_reset_on_fork:1; 629 unsigned sched_contributes_to_load:1; 630 unsigned sched_migrated:1; 631 unsigned sched_remote_wakeup:1; 632 /* Force alignment to the next boundary: */ 633 unsigned :0; 634 635 /* Unserialized, strictly 'current' */ 636 637 /* Bit to tell LSMs we're in execve(): */ 638 unsigned in_execve:1; 639 unsigned in_iowait:1; 640 #ifndef TIF_RESTORE_SIGMASK 641 unsigned restore_sigmask:1; 642 #endif 643 #ifdef CONFIG_MEMCG 644 unsigned memcg_may_oom:1; 645 #ifndef CONFIG_SLOB 646 unsigned memcg_kmem_skip_account:1; 647 #endif 648 #endif 649 #ifdef CONFIG_COMPAT_BRK 650 unsigned brk_randomized:1; 651 #endif 652 #ifdef CONFIG_CGROUPS 653 /* disallow userland-initiated cgroup migration */ 654 unsigned no_cgroup_migration:1; 655 #endif 656 657 unsigned long atomic_flags; /* Flags requiring atomic access. */ 658 659 struct restart_block restart_block; 660 661 pid_t pid; 662 pid_t tgid; 663 664 #ifdef CONFIG_CC_STACKPROTECTOR 665 /* Canary value for the -fstack-protector GCC feature: */ 666 unsigned long stack_canary; 667 #endif 668 /* 669 * Pointers to the (original) parent process, youngest child, younger sibling, 670 * older sibling, respectively. (p->father can be replaced with 671 * p->real_parent->pid) 672 */ 673 674 /* Real parent process: */ 675 struct task_struct __rcu *real_parent; 676 677 /* Recipient of SIGCHLD, wait4() reports: */ 678 struct task_struct __rcu *parent; 679 680 /* 681 * Children/sibling form the list of natural children: 682 */ 683 struct list_head children; 684 struct list_head sibling; 685 struct task_struct *group_leader; 686 687 /* 688 * 'ptraced' is the list of tasks this task is using ptrace() on. 689 * 690 * This includes both natural children and PTRACE_ATTACH targets. 691 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 692 */ 693 struct list_head ptraced; 694 struct list_head ptrace_entry; 695 696 /* PID/PID hash table linkage. */ 697 struct pid_link pids[PIDTYPE_MAX]; 698 struct list_head thread_group; 699 struct list_head thread_node; 700 701 struct completion *vfork_done; 702 703 /* CLONE_CHILD_SETTID: */ 704 int __user *set_child_tid; 705 706 /* CLONE_CHILD_CLEARTID: */ 707 int __user *clear_child_tid; 708 709 u64 utime; 710 u64 stime; 711 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 712 u64 utimescaled; 713 u64 stimescaled; 714 #endif 715 u64 gtime; 716 struct prev_cputime prev_cputime; 717 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 718 struct vtime vtime; 719 #endif 720 721 #ifdef CONFIG_NO_HZ_FULL 722 atomic_t tick_dep_mask; 723 #endif 724 /* Context switch counts: */ 725 unsigned long nvcsw; 726 unsigned long nivcsw; 727 728 /* Monotonic time in nsecs: */ 729 u64 start_time; 730 731 /* Boot based time in nsecs: */ 732 u64 real_start_time; 733 734 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 735 unsigned long min_flt; 736 unsigned long maj_flt; 737 738 #ifdef CONFIG_POSIX_TIMERS 739 struct task_cputime cputime_expires; 740 struct list_head cpu_timers[3]; 741 #endif 742 743 /* Process credentials: */ 744 745 /* Tracer's credentials at attach: */ 746 const struct cred __rcu *ptracer_cred; 747 748 /* Objective and real subjective task credentials (COW): */ 749 const struct cred __rcu *real_cred; 750 751 /* Effective (overridable) subjective task credentials (COW): */ 752 const struct cred __rcu *cred; 753 754 /* 755 * executable name, excluding path. 756 * 757 * - normally initialized setup_new_exec() 758 * - access it with [gs]et_task_comm() 759 * - lock it with task_lock() 760 */ 761 char comm[TASK_COMM_LEN]; 762 763 struct nameidata *nameidata; 764 765 #ifdef CONFIG_SYSVIPC 766 struct sysv_sem sysvsem; 767 struct sysv_shm sysvshm; 768 #endif 769 #ifdef CONFIG_DETECT_HUNG_TASK 770 unsigned long last_switch_count; 771 #endif 772 /* Filesystem information: */ 773 struct fs_struct *fs; 774 775 /* Open file information: */ 776 struct files_struct *files; 777 778 /* Namespaces: */ 779 struct nsproxy *nsproxy; 780 781 /* Signal handlers: */ 782 struct signal_struct *signal; 783 struct sighand_struct *sighand; 784 sigset_t blocked; 785 sigset_t real_blocked; 786 /* Restored if set_restore_sigmask() was used: */ 787 sigset_t saved_sigmask; 788 struct sigpending pending; 789 unsigned long sas_ss_sp; 790 size_t sas_ss_size; 791 unsigned int sas_ss_flags; 792 793 struct callback_head *task_works; 794 795 struct audit_context *audit_context; 796 #ifdef CONFIG_AUDITSYSCALL 797 kuid_t loginuid; 798 unsigned int sessionid; 799 #endif 800 struct seccomp seccomp; 801 802 /* Thread group tracking: */ 803 u32 parent_exec_id; 804 u32 self_exec_id; 805 806 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 807 spinlock_t alloc_lock; 808 809 /* Protection of the PI data structures: */ 810 raw_spinlock_t pi_lock; 811 812 struct wake_q_node wake_q; 813 814 #ifdef CONFIG_RT_MUTEXES 815 /* PI waiters blocked on a rt_mutex held by this task: */ 816 struct rb_root_cached pi_waiters; 817 /* Updated under owner's pi_lock and rq lock */ 818 struct task_struct *pi_top_task; 819 /* Deadlock detection and priority inheritance handling: */ 820 struct rt_mutex_waiter *pi_blocked_on; 821 #endif 822 823 #ifdef CONFIG_DEBUG_MUTEXES 824 /* Mutex deadlock detection: */ 825 struct mutex_waiter *blocked_on; 826 #endif 827 828 #ifdef CONFIG_TRACE_IRQFLAGS 829 unsigned int irq_events; 830 unsigned long hardirq_enable_ip; 831 unsigned long hardirq_disable_ip; 832 unsigned int hardirq_enable_event; 833 unsigned int hardirq_disable_event; 834 int hardirqs_enabled; 835 int hardirq_context; 836 unsigned long softirq_disable_ip; 837 unsigned long softirq_enable_ip; 838 unsigned int softirq_disable_event; 839 unsigned int softirq_enable_event; 840 int softirqs_enabled; 841 int softirq_context; 842 #endif 843 844 #ifdef CONFIG_LOCKDEP 845 # define MAX_LOCK_DEPTH 48UL 846 u64 curr_chain_key; 847 int lockdep_depth; 848 unsigned int lockdep_recursion; 849 struct held_lock held_locks[MAX_LOCK_DEPTH]; 850 #endif 851 852 #ifdef CONFIG_LOCKDEP_CROSSRELEASE 853 #define MAX_XHLOCKS_NR 64UL 854 struct hist_lock *xhlocks; /* Crossrelease history locks */ 855 unsigned int xhlock_idx; 856 /* For restoring at history boundaries */ 857 unsigned int xhlock_idx_hist[XHLOCK_CTX_NR]; 858 unsigned int hist_id; 859 /* For overwrite check at each context exit */ 860 unsigned int hist_id_save[XHLOCK_CTX_NR]; 861 #endif 862 863 #ifdef CONFIG_UBSAN 864 unsigned int in_ubsan; 865 #endif 866 867 /* Journalling filesystem info: */ 868 void *journal_info; 869 870 /* Stacked block device info: */ 871 struct bio_list *bio_list; 872 873 #ifdef CONFIG_BLOCK 874 /* Stack plugging: */ 875 struct blk_plug *plug; 876 #endif 877 878 /* VM state: */ 879 struct reclaim_state *reclaim_state; 880 881 struct backing_dev_info *backing_dev_info; 882 883 struct io_context *io_context; 884 885 /* Ptrace state: */ 886 unsigned long ptrace_message; 887 siginfo_t *last_siginfo; 888 889 struct task_io_accounting ioac; 890 #ifdef CONFIG_TASK_XACCT 891 /* Accumulated RSS usage: */ 892 u64 acct_rss_mem1; 893 /* Accumulated virtual memory usage: */ 894 u64 acct_vm_mem1; 895 /* stime + utime since last update: */ 896 u64 acct_timexpd; 897 #endif 898 #ifdef CONFIG_CPUSETS 899 /* Protected by ->alloc_lock: */ 900 nodemask_t mems_allowed; 901 /* Seqence number to catch updates: */ 902 seqcount_t mems_allowed_seq; 903 int cpuset_mem_spread_rotor; 904 int cpuset_slab_spread_rotor; 905 #endif 906 #ifdef CONFIG_CGROUPS 907 /* Control Group info protected by css_set_lock: */ 908 struct css_set __rcu *cgroups; 909 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 910 struct list_head cg_list; 911 #endif 912 #ifdef CONFIG_INTEL_RDT 913 u32 closid; 914 u32 rmid; 915 #endif 916 #ifdef CONFIG_FUTEX 917 struct robust_list_head __user *robust_list; 918 #ifdef CONFIG_COMPAT 919 struct compat_robust_list_head __user *compat_robust_list; 920 #endif 921 struct list_head pi_state_list; 922 struct futex_pi_state *pi_state_cache; 923 #endif 924 #ifdef CONFIG_PERF_EVENTS 925 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 926 struct mutex perf_event_mutex; 927 struct list_head perf_event_list; 928 #endif 929 #ifdef CONFIG_DEBUG_PREEMPT 930 unsigned long preempt_disable_ip; 931 #endif 932 #ifdef CONFIG_NUMA 933 /* Protected by alloc_lock: */ 934 struct mempolicy *mempolicy; 935 short il_prev; 936 short pref_node_fork; 937 #endif 938 #ifdef CONFIG_NUMA_BALANCING 939 int numa_scan_seq; 940 unsigned int numa_scan_period; 941 unsigned int numa_scan_period_max; 942 int numa_preferred_nid; 943 unsigned long numa_migrate_retry; 944 /* Migration stamp: */ 945 u64 node_stamp; 946 u64 last_task_numa_placement; 947 u64 last_sum_exec_runtime; 948 struct callback_head numa_work; 949 950 struct list_head numa_entry; 951 struct numa_group *numa_group; 952 953 /* 954 * numa_faults is an array split into four regions: 955 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 956 * in this precise order. 957 * 958 * faults_memory: Exponential decaying average of faults on a per-node 959 * basis. Scheduling placement decisions are made based on these 960 * counts. The values remain static for the duration of a PTE scan. 961 * faults_cpu: Track the nodes the process was running on when a NUMA 962 * hinting fault was incurred. 963 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 964 * during the current scan window. When the scan completes, the counts 965 * in faults_memory and faults_cpu decay and these values are copied. 966 */ 967 unsigned long *numa_faults; 968 unsigned long total_numa_faults; 969 970 /* 971 * numa_faults_locality tracks if faults recorded during the last 972 * scan window were remote/local or failed to migrate. The task scan 973 * period is adapted based on the locality of the faults with different 974 * weights depending on whether they were shared or private faults 975 */ 976 unsigned long numa_faults_locality[3]; 977 978 unsigned long numa_pages_migrated; 979 #endif /* CONFIG_NUMA_BALANCING */ 980 981 struct tlbflush_unmap_batch tlb_ubc; 982 983 struct rcu_head rcu; 984 985 /* Cache last used pipe for splice(): */ 986 struct pipe_inode_info *splice_pipe; 987 988 struct page_frag task_frag; 989 990 #ifdef CONFIG_TASK_DELAY_ACCT 991 struct task_delay_info *delays; 992 #endif 993 994 #ifdef CONFIG_FAULT_INJECTION 995 int make_it_fail; 996 unsigned int fail_nth; 997 #endif 998 /* 999 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1000 * balance_dirty_pages() for a dirty throttling pause: 1001 */ 1002 int nr_dirtied; 1003 int nr_dirtied_pause; 1004 /* Start of a write-and-pause period: */ 1005 unsigned long dirty_paused_when; 1006 1007 #ifdef CONFIG_LATENCYTOP 1008 int latency_record_count; 1009 struct latency_record latency_record[LT_SAVECOUNT]; 1010 #endif 1011 /* 1012 * Time slack values; these are used to round up poll() and 1013 * select() etc timeout values. These are in nanoseconds. 1014 */ 1015 u64 timer_slack_ns; 1016 u64 default_timer_slack_ns; 1017 1018 #ifdef CONFIG_KASAN 1019 unsigned int kasan_depth; 1020 #endif 1021 1022 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1023 /* Index of current stored address in ret_stack: */ 1024 int curr_ret_stack; 1025 1026 /* Stack of return addresses for return function tracing: */ 1027 struct ftrace_ret_stack *ret_stack; 1028 1029 /* Timestamp for last schedule: */ 1030 unsigned long long ftrace_timestamp; 1031 1032 /* 1033 * Number of functions that haven't been traced 1034 * because of depth overrun: 1035 */ 1036 atomic_t trace_overrun; 1037 1038 /* Pause tracing: */ 1039 atomic_t tracing_graph_pause; 1040 #endif 1041 1042 #ifdef CONFIG_TRACING 1043 /* State flags for use by tracers: */ 1044 unsigned long trace; 1045 1046 /* Bitmask and counter of trace recursion: */ 1047 unsigned long trace_recursion; 1048 #endif /* CONFIG_TRACING */ 1049 1050 #ifdef CONFIG_KCOV 1051 /* Coverage collection mode enabled for this task (0 if disabled): */ 1052 enum kcov_mode kcov_mode; 1053 1054 /* Size of the kcov_area: */ 1055 unsigned int kcov_size; 1056 1057 /* Buffer for coverage collection: */ 1058 void *kcov_area; 1059 1060 /* KCOV descriptor wired with this task or NULL: */ 1061 struct kcov *kcov; 1062 #endif 1063 1064 #ifdef CONFIG_MEMCG 1065 struct mem_cgroup *memcg_in_oom; 1066 gfp_t memcg_oom_gfp_mask; 1067 int memcg_oom_order; 1068 1069 /* Number of pages to reclaim on returning to userland: */ 1070 unsigned int memcg_nr_pages_over_high; 1071 #endif 1072 1073 #ifdef CONFIG_UPROBES 1074 struct uprobe_task *utask; 1075 #endif 1076 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1077 unsigned int sequential_io; 1078 unsigned int sequential_io_avg; 1079 #endif 1080 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1081 unsigned long task_state_change; 1082 #endif 1083 int pagefault_disabled; 1084 #ifdef CONFIG_MMU 1085 struct task_struct *oom_reaper_list; 1086 #endif 1087 #ifdef CONFIG_VMAP_STACK 1088 struct vm_struct *stack_vm_area; 1089 #endif 1090 #ifdef CONFIG_THREAD_INFO_IN_TASK 1091 /* A live task holds one reference: */ 1092 atomic_t stack_refcount; 1093 #endif 1094 #ifdef CONFIG_LIVEPATCH 1095 int patch_state; 1096 #endif 1097 #ifdef CONFIG_SECURITY 1098 /* Used by LSM modules for access restriction: */ 1099 void *security; 1100 #endif 1101 1102 /* 1103 * New fields for task_struct should be added above here, so that 1104 * they are included in the randomized portion of task_struct. 1105 */ 1106 randomized_struct_fields_end 1107 1108 /* CPU-specific state of this task: */ 1109 struct thread_struct thread; 1110 1111 /* 1112 * WARNING: on x86, 'thread_struct' contains a variable-sized 1113 * structure. It *MUST* be at the end of 'task_struct'. 1114 * 1115 * Do not put anything below here! 1116 */ 1117 }; 1118 1119 static inline struct pid *task_pid(struct task_struct *task) 1120 { 1121 return task->pids[PIDTYPE_PID].pid; 1122 } 1123 1124 static inline struct pid *task_tgid(struct task_struct *task) 1125 { 1126 return task->group_leader->pids[PIDTYPE_PID].pid; 1127 } 1128 1129 /* 1130 * Without tasklist or RCU lock it is not safe to dereference 1131 * the result of task_pgrp/task_session even if task == current, 1132 * we can race with another thread doing sys_setsid/sys_setpgid. 1133 */ 1134 static inline struct pid *task_pgrp(struct task_struct *task) 1135 { 1136 return task->group_leader->pids[PIDTYPE_PGID].pid; 1137 } 1138 1139 static inline struct pid *task_session(struct task_struct *task) 1140 { 1141 return task->group_leader->pids[PIDTYPE_SID].pid; 1142 } 1143 1144 /* 1145 * the helpers to get the task's different pids as they are seen 1146 * from various namespaces 1147 * 1148 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1149 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1150 * current. 1151 * task_xid_nr_ns() : id seen from the ns specified; 1152 * 1153 * see also pid_nr() etc in include/linux/pid.h 1154 */ 1155 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1156 1157 static inline pid_t task_pid_nr(struct task_struct *tsk) 1158 { 1159 return tsk->pid; 1160 } 1161 1162 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1163 { 1164 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1165 } 1166 1167 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1168 { 1169 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1170 } 1171 1172 1173 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1174 { 1175 return tsk->tgid; 1176 } 1177 1178 /** 1179 * pid_alive - check that a task structure is not stale 1180 * @p: Task structure to be checked. 1181 * 1182 * Test if a process is not yet dead (at most zombie state) 1183 * If pid_alive fails, then pointers within the task structure 1184 * can be stale and must not be dereferenced. 1185 * 1186 * Return: 1 if the process is alive. 0 otherwise. 1187 */ 1188 static inline int pid_alive(const struct task_struct *p) 1189 { 1190 return p->pids[PIDTYPE_PID].pid != NULL; 1191 } 1192 1193 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1194 { 1195 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1196 } 1197 1198 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1199 { 1200 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1201 } 1202 1203 1204 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1205 { 1206 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1207 } 1208 1209 static inline pid_t task_session_vnr(struct task_struct *tsk) 1210 { 1211 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1212 } 1213 1214 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1215 { 1216 return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns); 1217 } 1218 1219 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1220 { 1221 return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL); 1222 } 1223 1224 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1225 { 1226 pid_t pid = 0; 1227 1228 rcu_read_lock(); 1229 if (pid_alive(tsk)) 1230 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1231 rcu_read_unlock(); 1232 1233 return pid; 1234 } 1235 1236 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1237 { 1238 return task_ppid_nr_ns(tsk, &init_pid_ns); 1239 } 1240 1241 /* Obsolete, do not use: */ 1242 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1243 { 1244 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1245 } 1246 1247 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1248 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1249 1250 static inline unsigned int task_state_index(struct task_struct *tsk) 1251 { 1252 unsigned int tsk_state = READ_ONCE(tsk->state); 1253 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT; 1254 1255 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1256 1257 if (tsk_state == TASK_IDLE) 1258 state = TASK_REPORT_IDLE; 1259 1260 return fls(state); 1261 } 1262 1263 static inline char task_index_to_char(unsigned int state) 1264 { 1265 static const char state_char[] = "RSDTtXZPI"; 1266 1267 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1268 1269 return state_char[state]; 1270 } 1271 1272 static inline char task_state_to_char(struct task_struct *tsk) 1273 { 1274 return task_index_to_char(task_state_index(tsk)); 1275 } 1276 1277 /** 1278 * is_global_init - check if a task structure is init. Since init 1279 * is free to have sub-threads we need to check tgid. 1280 * @tsk: Task structure to be checked. 1281 * 1282 * Check if a task structure is the first user space task the kernel created. 1283 * 1284 * Return: 1 if the task structure is init. 0 otherwise. 1285 */ 1286 static inline int is_global_init(struct task_struct *tsk) 1287 { 1288 return task_tgid_nr(tsk) == 1; 1289 } 1290 1291 extern struct pid *cad_pid; 1292 1293 /* 1294 * Per process flags 1295 */ 1296 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1297 #define PF_EXITING 0x00000004 /* Getting shut down */ 1298 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */ 1299 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ 1300 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1301 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1302 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1303 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1304 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1305 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1306 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1307 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1308 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1309 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */ 1310 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1311 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1312 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1313 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1314 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1315 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */ 1316 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1317 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1318 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ 1319 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */ 1320 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1321 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ 1322 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1323 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1324 1325 /* 1326 * Only the _current_ task can read/write to tsk->flags, but other 1327 * tasks can access tsk->flags in readonly mode for example 1328 * with tsk_used_math (like during threaded core dumping). 1329 * There is however an exception to this rule during ptrace 1330 * or during fork: the ptracer task is allowed to write to the 1331 * child->flags of its traced child (same goes for fork, the parent 1332 * can write to the child->flags), because we're guaranteed the 1333 * child is not running and in turn not changing child->flags 1334 * at the same time the parent does it. 1335 */ 1336 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1337 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1338 #define clear_used_math() clear_stopped_child_used_math(current) 1339 #define set_used_math() set_stopped_child_used_math(current) 1340 1341 #define conditional_stopped_child_used_math(condition, child) \ 1342 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1343 1344 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1345 1346 #define copy_to_stopped_child_used_math(child) \ 1347 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1348 1349 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1350 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1351 #define used_math() tsk_used_math(current) 1352 1353 static inline bool is_percpu_thread(void) 1354 { 1355 #ifdef CONFIG_SMP 1356 return (current->flags & PF_NO_SETAFFINITY) && 1357 (current->nr_cpus_allowed == 1); 1358 #else 1359 return true; 1360 #endif 1361 } 1362 1363 /* Per-process atomic flags. */ 1364 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1365 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1366 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1367 1368 1369 #define TASK_PFA_TEST(name, func) \ 1370 static inline bool task_##func(struct task_struct *p) \ 1371 { return test_bit(PFA_##name, &p->atomic_flags); } 1372 1373 #define TASK_PFA_SET(name, func) \ 1374 static inline void task_set_##func(struct task_struct *p) \ 1375 { set_bit(PFA_##name, &p->atomic_flags); } 1376 1377 #define TASK_PFA_CLEAR(name, func) \ 1378 static inline void task_clear_##func(struct task_struct *p) \ 1379 { clear_bit(PFA_##name, &p->atomic_flags); } 1380 1381 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1382 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1383 1384 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1385 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1386 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1387 1388 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1389 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1390 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1391 1392 static inline void 1393 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1394 { 1395 current->flags &= ~flags; 1396 current->flags |= orig_flags & flags; 1397 } 1398 1399 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1400 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); 1401 #ifdef CONFIG_SMP 1402 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1403 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1404 #else 1405 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1406 { 1407 } 1408 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1409 { 1410 if (!cpumask_test_cpu(0, new_mask)) 1411 return -EINVAL; 1412 return 0; 1413 } 1414 #endif 1415 1416 #ifndef cpu_relax_yield 1417 #define cpu_relax_yield() cpu_relax() 1418 #endif 1419 1420 extern int yield_to(struct task_struct *p, bool preempt); 1421 extern void set_user_nice(struct task_struct *p, long nice); 1422 extern int task_prio(const struct task_struct *p); 1423 1424 /** 1425 * task_nice - return the nice value of a given task. 1426 * @p: the task in question. 1427 * 1428 * Return: The nice value [ -20 ... 0 ... 19 ]. 1429 */ 1430 static inline int task_nice(const struct task_struct *p) 1431 { 1432 return PRIO_TO_NICE((p)->static_prio); 1433 } 1434 1435 extern int can_nice(const struct task_struct *p, const int nice); 1436 extern int task_curr(const struct task_struct *p); 1437 extern int idle_cpu(int cpu); 1438 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1439 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1440 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1441 extern struct task_struct *idle_task(int cpu); 1442 1443 /** 1444 * is_idle_task - is the specified task an idle task? 1445 * @p: the task in question. 1446 * 1447 * Return: 1 if @p is an idle task. 0 otherwise. 1448 */ 1449 static inline bool is_idle_task(const struct task_struct *p) 1450 { 1451 return !!(p->flags & PF_IDLE); 1452 } 1453 1454 extern struct task_struct *curr_task(int cpu); 1455 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1456 1457 void yield(void); 1458 1459 union thread_union { 1460 #ifndef CONFIG_THREAD_INFO_IN_TASK 1461 struct thread_info thread_info; 1462 #endif 1463 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1464 }; 1465 1466 #ifdef CONFIG_THREAD_INFO_IN_TASK 1467 static inline struct thread_info *task_thread_info(struct task_struct *task) 1468 { 1469 return &task->thread_info; 1470 } 1471 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1472 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1473 #endif 1474 1475 /* 1476 * find a task by one of its numerical ids 1477 * 1478 * find_task_by_pid_ns(): 1479 * finds a task by its pid in the specified namespace 1480 * find_task_by_vpid(): 1481 * finds a task by its virtual pid 1482 * 1483 * see also find_vpid() etc in include/linux/pid.h 1484 */ 1485 1486 extern struct task_struct *find_task_by_vpid(pid_t nr); 1487 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1488 1489 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1490 extern int wake_up_process(struct task_struct *tsk); 1491 extern void wake_up_new_task(struct task_struct *tsk); 1492 1493 #ifdef CONFIG_SMP 1494 extern void kick_process(struct task_struct *tsk); 1495 #else 1496 static inline void kick_process(struct task_struct *tsk) { } 1497 #endif 1498 1499 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1500 1501 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1502 { 1503 __set_task_comm(tsk, from, false); 1504 } 1505 1506 extern char *get_task_comm(char *to, struct task_struct *tsk); 1507 1508 #ifdef CONFIG_SMP 1509 void scheduler_ipi(void); 1510 extern unsigned long wait_task_inactive(struct task_struct *, long match_state); 1511 #else 1512 static inline void scheduler_ipi(void) { } 1513 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state) 1514 { 1515 return 1; 1516 } 1517 #endif 1518 1519 /* 1520 * Set thread flags in other task's structures. 1521 * See asm/thread_info.h for TIF_xxxx flags available: 1522 */ 1523 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1524 { 1525 set_ti_thread_flag(task_thread_info(tsk), flag); 1526 } 1527 1528 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1529 { 1530 clear_ti_thread_flag(task_thread_info(tsk), flag); 1531 } 1532 1533 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1534 { 1535 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1536 } 1537 1538 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1539 { 1540 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1541 } 1542 1543 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1544 { 1545 return test_ti_thread_flag(task_thread_info(tsk), flag); 1546 } 1547 1548 static inline void set_tsk_need_resched(struct task_struct *tsk) 1549 { 1550 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1551 } 1552 1553 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1554 { 1555 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1556 } 1557 1558 static inline int test_tsk_need_resched(struct task_struct *tsk) 1559 { 1560 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 1561 } 1562 1563 /* 1564 * cond_resched() and cond_resched_lock(): latency reduction via 1565 * explicit rescheduling in places that are safe. The return 1566 * value indicates whether a reschedule was done in fact. 1567 * cond_resched_lock() will drop the spinlock before scheduling, 1568 * cond_resched_softirq() will enable bhs before scheduling. 1569 */ 1570 #ifndef CONFIG_PREEMPT 1571 extern int _cond_resched(void); 1572 #else 1573 static inline int _cond_resched(void) { return 0; } 1574 #endif 1575 1576 #define cond_resched() ({ \ 1577 ___might_sleep(__FILE__, __LINE__, 0); \ 1578 _cond_resched(); \ 1579 }) 1580 1581 extern int __cond_resched_lock(spinlock_t *lock); 1582 1583 #define cond_resched_lock(lock) ({ \ 1584 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\ 1585 __cond_resched_lock(lock); \ 1586 }) 1587 1588 extern int __cond_resched_softirq(void); 1589 1590 #define cond_resched_softirq() ({ \ 1591 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \ 1592 __cond_resched_softirq(); \ 1593 }) 1594 1595 static inline void cond_resched_rcu(void) 1596 { 1597 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 1598 rcu_read_unlock(); 1599 cond_resched(); 1600 rcu_read_lock(); 1601 #endif 1602 } 1603 1604 /* 1605 * Does a critical section need to be broken due to another 1606 * task waiting?: (technically does not depend on CONFIG_PREEMPT, 1607 * but a general need for low latency) 1608 */ 1609 static inline int spin_needbreak(spinlock_t *lock) 1610 { 1611 #ifdef CONFIG_PREEMPT 1612 return spin_is_contended(lock); 1613 #else 1614 return 0; 1615 #endif 1616 } 1617 1618 static __always_inline bool need_resched(void) 1619 { 1620 return unlikely(tif_need_resched()); 1621 } 1622 1623 /* 1624 * Wrappers for p->thread_info->cpu access. No-op on UP. 1625 */ 1626 #ifdef CONFIG_SMP 1627 1628 static inline unsigned int task_cpu(const struct task_struct *p) 1629 { 1630 #ifdef CONFIG_THREAD_INFO_IN_TASK 1631 return p->cpu; 1632 #else 1633 return task_thread_info(p)->cpu; 1634 #endif 1635 } 1636 1637 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 1638 1639 #else 1640 1641 static inline unsigned int task_cpu(const struct task_struct *p) 1642 { 1643 return 0; 1644 } 1645 1646 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 1647 { 1648 } 1649 1650 #endif /* CONFIG_SMP */ 1651 1652 /* 1653 * In order to reduce various lock holder preemption latencies provide an 1654 * interface to see if a vCPU is currently running or not. 1655 * 1656 * This allows us to terminate optimistic spin loops and block, analogous to 1657 * the native optimistic spin heuristic of testing if the lock owner task is 1658 * running or not. 1659 */ 1660 #ifndef vcpu_is_preempted 1661 # define vcpu_is_preempted(cpu) false 1662 #endif 1663 1664 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 1665 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 1666 1667 #ifndef TASK_SIZE_OF 1668 #define TASK_SIZE_OF(tsk) TASK_SIZE 1669 #endif 1670 1671 #endif 1672