1 #ifndef _LINUX_SCHED_H 2 #define _LINUX_SCHED_H 3 4 /* 5 * Define 'struct task_struct' and provide the main scheduler 6 * APIs (schedule(), wakeup variants, etc.) 7 */ 8 9 #include <uapi/linux/sched.h> 10 11 #include <asm/current.h> 12 13 #include <linux/pid.h> 14 #include <linux/sem.h> 15 #include <linux/shm.h> 16 #include <linux/kcov.h> 17 #include <linux/mutex.h> 18 #include <linux/plist.h> 19 #include <linux/hrtimer.h> 20 #include <linux/seccomp.h> 21 #include <linux/nodemask.h> 22 #include <linux/rcupdate.h> 23 #include <linux/resource.h> 24 #include <linux/latencytop.h> 25 #include <linux/sched/prio.h> 26 #include <linux/signal_types.h> 27 #include <linux/mm_types_task.h> 28 #include <linux/task_io_accounting.h> 29 30 /* task_struct member predeclarations (sorted alphabetically): */ 31 struct audit_context; 32 struct backing_dev_info; 33 struct bio_list; 34 struct blk_plug; 35 struct cfs_rq; 36 struct fs_struct; 37 struct futex_pi_state; 38 struct io_context; 39 struct mempolicy; 40 struct nameidata; 41 struct nsproxy; 42 struct perf_event_context; 43 struct pid_namespace; 44 struct pipe_inode_info; 45 struct rcu_node; 46 struct reclaim_state; 47 struct robust_list_head; 48 struct sched_attr; 49 struct sched_param; 50 struct seq_file; 51 struct sighand_struct; 52 struct signal_struct; 53 struct task_delay_info; 54 struct task_group; 55 56 /* 57 * Task state bitmask. NOTE! These bits are also 58 * encoded in fs/proc/array.c: get_task_state(). 59 * 60 * We have two separate sets of flags: task->state 61 * is about runnability, while task->exit_state are 62 * about the task exiting. Confusing, but this way 63 * modifying one set can't modify the other one by 64 * mistake. 65 */ 66 67 /* Used in tsk->state: */ 68 #define TASK_RUNNING 0 69 #define TASK_INTERRUPTIBLE 1 70 #define TASK_UNINTERRUPTIBLE 2 71 #define __TASK_STOPPED 4 72 #define __TASK_TRACED 8 73 /* Used in tsk->exit_state: */ 74 #define EXIT_DEAD 16 75 #define EXIT_ZOMBIE 32 76 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 77 /* Used in tsk->state again: */ 78 #define TASK_DEAD 64 79 #define TASK_WAKEKILL 128 80 #define TASK_WAKING 256 81 #define TASK_PARKED 512 82 #define TASK_NOLOAD 1024 83 #define TASK_NEW 2048 84 #define TASK_STATE_MAX 4096 85 86 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn" 87 88 /* Convenience macros for the sake of set_current_state: */ 89 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 90 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 91 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) 92 93 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 94 95 /* Convenience macros for the sake of wake_up(): */ 96 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 97 #define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED) 98 99 /* get_task_state(): */ 100 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 101 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 102 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD) 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 cpumask_var_t cpu_isolated_map; 170 171 extern void scheduler_tick(void); 172 173 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 174 175 extern long schedule_timeout(long timeout); 176 extern long schedule_timeout_interruptible(long timeout); 177 extern long schedule_timeout_killable(long timeout); 178 extern long schedule_timeout_uninterruptible(long timeout); 179 extern long schedule_timeout_idle(long timeout); 180 asmlinkage void schedule(void); 181 extern void schedule_preempt_disabled(void); 182 183 extern int __must_check io_schedule_prepare(void); 184 extern void io_schedule_finish(int token); 185 extern long io_schedule_timeout(long timeout); 186 extern void io_schedule(void); 187 188 /** 189 * struct prev_cputime - snapshot of system and user cputime 190 * @utime: time spent in user mode 191 * @stime: time spent in system mode 192 * @lock: protects the above two fields 193 * 194 * Stores previous user/system time values such that we can guarantee 195 * monotonicity. 196 */ 197 struct prev_cputime { 198 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 199 u64 utime; 200 u64 stime; 201 raw_spinlock_t lock; 202 #endif 203 }; 204 205 /** 206 * struct task_cputime - collected CPU time counts 207 * @utime: time spent in user mode, in nanoseconds 208 * @stime: time spent in kernel mode, in nanoseconds 209 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds 210 * 211 * This structure groups together three kinds of CPU time that are tracked for 212 * threads and thread groups. Most things considering CPU time want to group 213 * these counts together and treat all three of them in parallel. 214 */ 215 struct task_cputime { 216 u64 utime; 217 u64 stime; 218 unsigned long long sum_exec_runtime; 219 }; 220 221 /* Alternate field names when used on cache expirations: */ 222 #define virt_exp utime 223 #define prof_exp stime 224 #define sched_exp sum_exec_runtime 225 226 struct sched_info { 227 #ifdef CONFIG_SCHED_INFO 228 /* Cumulative counters: */ 229 230 /* # of times we have run on this CPU: */ 231 unsigned long pcount; 232 233 /* Time spent waiting on a runqueue: */ 234 unsigned long long run_delay; 235 236 /* Timestamps: */ 237 238 /* When did we last run on a CPU? */ 239 unsigned long long last_arrival; 240 241 /* When were we last queued to run? */ 242 unsigned long long last_queued; 243 244 #endif /* CONFIG_SCHED_INFO */ 245 }; 246 247 /* 248 * Integer metrics need fixed point arithmetic, e.g., sched/fair 249 * has a few: load, load_avg, util_avg, freq, and capacity. 250 * 251 * We define a basic fixed point arithmetic range, and then formalize 252 * all these metrics based on that basic range. 253 */ 254 # define SCHED_FIXEDPOINT_SHIFT 10 255 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 256 257 struct load_weight { 258 unsigned long weight; 259 u32 inv_weight; 260 }; 261 262 /* 263 * The load_avg/util_avg accumulates an infinite geometric series 264 * (see __update_load_avg() in kernel/sched/fair.c). 265 * 266 * [load_avg definition] 267 * 268 * load_avg = runnable% * scale_load_down(load) 269 * 270 * where runnable% is the time ratio that a sched_entity is runnable. 271 * For cfs_rq, it is the aggregated load_avg of all runnable and 272 * blocked sched_entities. 273 * 274 * load_avg may also take frequency scaling into account: 275 * 276 * load_avg = runnable% * scale_load_down(load) * freq% 277 * 278 * where freq% is the CPU frequency normalized to the highest frequency. 279 * 280 * [util_avg definition] 281 * 282 * util_avg = running% * SCHED_CAPACITY_SCALE 283 * 284 * where running% is the time ratio that a sched_entity is running on 285 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable 286 * and blocked sched_entities. 287 * 288 * util_avg may also factor frequency scaling and CPU capacity scaling: 289 * 290 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity% 291 * 292 * where freq% is the same as above, and capacity% is the CPU capacity 293 * normalized to the greatest capacity (due to uarch differences, etc). 294 * 295 * N.B., the above ratios (runnable%, running%, freq%, and capacity%) 296 * themselves are in the range of [0, 1]. To do fixed point arithmetics, 297 * we therefore scale them to as large a range as necessary. This is for 298 * example reflected by util_avg's SCHED_CAPACITY_SCALE. 299 * 300 * [Overflow issue] 301 * 302 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 303 * with the highest load (=88761), always runnable on a single cfs_rq, 304 * and should not overflow as the number already hits PID_MAX_LIMIT. 305 * 306 * For all other cases (including 32-bit kernels), struct load_weight's 307 * weight will overflow first before we do, because: 308 * 309 * Max(load_avg) <= Max(load.weight) 310 * 311 * Then it is the load_weight's responsibility to consider overflow 312 * issues. 313 */ 314 struct sched_avg { 315 u64 last_update_time; 316 u64 load_sum; 317 u32 util_sum; 318 u32 period_contrib; 319 unsigned long load_avg; 320 unsigned long util_avg; 321 }; 322 323 struct sched_statistics { 324 #ifdef CONFIG_SCHEDSTATS 325 u64 wait_start; 326 u64 wait_max; 327 u64 wait_count; 328 u64 wait_sum; 329 u64 iowait_count; 330 u64 iowait_sum; 331 332 u64 sleep_start; 333 u64 sleep_max; 334 s64 sum_sleep_runtime; 335 336 u64 block_start; 337 u64 block_max; 338 u64 exec_max; 339 u64 slice_max; 340 341 u64 nr_migrations_cold; 342 u64 nr_failed_migrations_affine; 343 u64 nr_failed_migrations_running; 344 u64 nr_failed_migrations_hot; 345 u64 nr_forced_migrations; 346 347 u64 nr_wakeups; 348 u64 nr_wakeups_sync; 349 u64 nr_wakeups_migrate; 350 u64 nr_wakeups_local; 351 u64 nr_wakeups_remote; 352 u64 nr_wakeups_affine; 353 u64 nr_wakeups_affine_attempts; 354 u64 nr_wakeups_passive; 355 u64 nr_wakeups_idle; 356 #endif 357 }; 358 359 struct sched_entity { 360 /* For load-balancing: */ 361 struct load_weight load; 362 struct rb_node run_node; 363 struct list_head group_node; 364 unsigned int on_rq; 365 366 u64 exec_start; 367 u64 sum_exec_runtime; 368 u64 vruntime; 369 u64 prev_sum_exec_runtime; 370 371 u64 nr_migrations; 372 373 struct sched_statistics statistics; 374 375 #ifdef CONFIG_FAIR_GROUP_SCHED 376 int depth; 377 struct sched_entity *parent; 378 /* rq on which this entity is (to be) queued: */ 379 struct cfs_rq *cfs_rq; 380 /* rq "owned" by this entity/group: */ 381 struct cfs_rq *my_q; 382 #endif 383 384 #ifdef CONFIG_SMP 385 /* 386 * Per entity load average tracking. 387 * 388 * Put into separate cache line so it does not 389 * collide with read-mostly values above. 390 */ 391 struct sched_avg avg ____cacheline_aligned_in_smp; 392 #endif 393 }; 394 395 struct sched_rt_entity { 396 struct list_head run_list; 397 unsigned long timeout; 398 unsigned long watchdog_stamp; 399 unsigned int time_slice; 400 unsigned short on_rq; 401 unsigned short on_list; 402 403 struct sched_rt_entity *back; 404 #ifdef CONFIG_RT_GROUP_SCHED 405 struct sched_rt_entity *parent; 406 /* rq on which this entity is (to be) queued: */ 407 struct rt_rq *rt_rq; 408 /* rq "owned" by this entity/group: */ 409 struct rt_rq *my_q; 410 #endif 411 }; 412 413 struct sched_dl_entity { 414 struct rb_node rb_node; 415 416 /* 417 * Original scheduling parameters. Copied here from sched_attr 418 * during sched_setattr(), they will remain the same until 419 * the next sched_setattr(). 420 */ 421 u64 dl_runtime; /* Maximum runtime for each instance */ 422 u64 dl_deadline; /* Relative deadline of each instance */ 423 u64 dl_period; /* Separation of two instances (period) */ 424 u64 dl_bw; /* dl_runtime / dl_deadline */ 425 426 /* 427 * Actual scheduling parameters. Initialized with the values above, 428 * they are continously updated during task execution. Note that 429 * the remaining runtime could be < 0 in case we are in overrun. 430 */ 431 s64 runtime; /* Remaining runtime for this instance */ 432 u64 deadline; /* Absolute deadline for this instance */ 433 unsigned int flags; /* Specifying the scheduler behaviour */ 434 435 /* 436 * Some bool flags: 437 * 438 * @dl_throttled tells if we exhausted the runtime. If so, the 439 * task has to wait for a replenishment to be performed at the 440 * next firing of dl_timer. 441 * 442 * @dl_boosted tells if we are boosted due to DI. If so we are 443 * outside bandwidth enforcement mechanism (but only until we 444 * exit the critical section); 445 * 446 * @dl_yielded tells if task gave up the CPU before consuming 447 * all its available runtime during the last job. 448 */ 449 int dl_throttled; 450 int dl_boosted; 451 int dl_yielded; 452 453 /* 454 * Bandwidth enforcement timer. Each -deadline task has its 455 * own bandwidth to be enforced, thus we need one timer per task. 456 */ 457 struct hrtimer dl_timer; 458 }; 459 460 union rcu_special { 461 struct { 462 u8 blocked; 463 u8 need_qs; 464 u8 exp_need_qs; 465 466 /* Otherwise the compiler can store garbage here: */ 467 u8 pad; 468 } b; /* Bits. */ 469 u32 s; /* Set of bits. */ 470 }; 471 472 enum perf_event_task_context { 473 perf_invalid_context = -1, 474 perf_hw_context = 0, 475 perf_sw_context, 476 perf_nr_task_contexts, 477 }; 478 479 struct wake_q_node { 480 struct wake_q_node *next; 481 }; 482 483 struct task_struct { 484 #ifdef CONFIG_THREAD_INFO_IN_TASK 485 /* 486 * For reasons of header soup (see current_thread_info()), this 487 * must be the first element of task_struct. 488 */ 489 struct thread_info thread_info; 490 #endif 491 /* -1 unrunnable, 0 runnable, >0 stopped: */ 492 volatile long state; 493 void *stack; 494 atomic_t usage; 495 /* Per task flags (PF_*), defined further below: */ 496 unsigned int flags; 497 unsigned int ptrace; 498 499 #ifdef CONFIG_SMP 500 struct llist_node wake_entry; 501 int on_cpu; 502 #ifdef CONFIG_THREAD_INFO_IN_TASK 503 /* Current CPU: */ 504 unsigned int cpu; 505 #endif 506 unsigned int wakee_flips; 507 unsigned long wakee_flip_decay_ts; 508 struct task_struct *last_wakee; 509 510 int wake_cpu; 511 #endif 512 int on_rq; 513 514 int prio; 515 int static_prio; 516 int normal_prio; 517 unsigned int rt_priority; 518 519 const struct sched_class *sched_class; 520 struct sched_entity se; 521 struct sched_rt_entity rt; 522 #ifdef CONFIG_CGROUP_SCHED 523 struct task_group *sched_task_group; 524 #endif 525 struct sched_dl_entity dl; 526 527 #ifdef CONFIG_PREEMPT_NOTIFIERS 528 /* List of struct preempt_notifier: */ 529 struct hlist_head preempt_notifiers; 530 #endif 531 532 #ifdef CONFIG_BLK_DEV_IO_TRACE 533 unsigned int btrace_seq; 534 #endif 535 536 unsigned int policy; 537 int nr_cpus_allowed; 538 cpumask_t cpus_allowed; 539 540 #ifdef CONFIG_PREEMPT_RCU 541 int rcu_read_lock_nesting; 542 union rcu_special rcu_read_unlock_special; 543 struct list_head rcu_node_entry; 544 struct rcu_node *rcu_blocked_node; 545 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 546 547 #ifdef CONFIG_TASKS_RCU 548 unsigned long rcu_tasks_nvcsw; 549 bool rcu_tasks_holdout; 550 struct list_head rcu_tasks_holdout_list; 551 int rcu_tasks_idle_cpu; 552 #endif /* #ifdef CONFIG_TASKS_RCU */ 553 554 struct sched_info sched_info; 555 556 struct list_head tasks; 557 #ifdef CONFIG_SMP 558 struct plist_node pushable_tasks; 559 struct rb_node pushable_dl_tasks; 560 #endif 561 562 struct mm_struct *mm; 563 struct mm_struct *active_mm; 564 565 /* Per-thread vma caching: */ 566 struct vmacache vmacache; 567 568 #ifdef SPLIT_RSS_COUNTING 569 struct task_rss_stat rss_stat; 570 #endif 571 int exit_state; 572 int exit_code; 573 int exit_signal; 574 /* The signal sent when the parent dies: */ 575 int pdeath_signal; 576 /* JOBCTL_*, siglock protected: */ 577 unsigned long jobctl; 578 579 /* Used for emulating ABI behavior of previous Linux versions: */ 580 unsigned int personality; 581 582 /* Scheduler bits, serialized by scheduler locks: */ 583 unsigned sched_reset_on_fork:1; 584 unsigned sched_contributes_to_load:1; 585 unsigned sched_migrated:1; 586 unsigned sched_remote_wakeup:1; 587 /* Force alignment to the next boundary: */ 588 unsigned :0; 589 590 /* Unserialized, strictly 'current' */ 591 592 /* Bit to tell LSMs we're in execve(): */ 593 unsigned in_execve:1; 594 unsigned in_iowait:1; 595 #ifndef TIF_RESTORE_SIGMASK 596 unsigned restore_sigmask:1; 597 #endif 598 #ifdef CONFIG_MEMCG 599 unsigned memcg_may_oom:1; 600 #ifndef CONFIG_SLOB 601 unsigned memcg_kmem_skip_account:1; 602 #endif 603 #endif 604 #ifdef CONFIG_COMPAT_BRK 605 unsigned brk_randomized:1; 606 #endif 607 #ifdef CONFIG_CGROUPS 608 /* disallow userland-initiated cgroup migration */ 609 unsigned no_cgroup_migration:1; 610 #endif 611 612 unsigned long atomic_flags; /* Flags requiring atomic access. */ 613 614 struct restart_block restart_block; 615 616 pid_t pid; 617 pid_t tgid; 618 619 #ifdef CONFIG_CC_STACKPROTECTOR 620 /* Canary value for the -fstack-protector GCC feature: */ 621 unsigned long stack_canary; 622 #endif 623 /* 624 * Pointers to the (original) parent process, youngest child, younger sibling, 625 * older sibling, respectively. (p->father can be replaced with 626 * p->real_parent->pid) 627 */ 628 629 /* Real parent process: */ 630 struct task_struct __rcu *real_parent; 631 632 /* Recipient of SIGCHLD, wait4() reports: */ 633 struct task_struct __rcu *parent; 634 635 /* 636 * Children/sibling form the list of natural children: 637 */ 638 struct list_head children; 639 struct list_head sibling; 640 struct task_struct *group_leader; 641 642 /* 643 * 'ptraced' is the list of tasks this task is using ptrace() on. 644 * 645 * This includes both natural children and PTRACE_ATTACH targets. 646 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 647 */ 648 struct list_head ptraced; 649 struct list_head ptrace_entry; 650 651 /* PID/PID hash table linkage. */ 652 struct pid_link pids[PIDTYPE_MAX]; 653 struct list_head thread_group; 654 struct list_head thread_node; 655 656 struct completion *vfork_done; 657 658 /* CLONE_CHILD_SETTID: */ 659 int __user *set_child_tid; 660 661 /* CLONE_CHILD_CLEARTID: */ 662 int __user *clear_child_tid; 663 664 u64 utime; 665 u64 stime; 666 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 667 u64 utimescaled; 668 u64 stimescaled; 669 #endif 670 u64 gtime; 671 struct prev_cputime prev_cputime; 672 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 673 seqcount_t vtime_seqcount; 674 unsigned long long vtime_snap; 675 enum { 676 /* Task is sleeping or running in a CPU with VTIME inactive: */ 677 VTIME_INACTIVE = 0, 678 /* Task runs in userspace in a CPU with VTIME active: */ 679 VTIME_USER, 680 /* Task runs in kernelspace in a CPU with VTIME active: */ 681 VTIME_SYS, 682 } vtime_snap_whence; 683 #endif 684 685 #ifdef CONFIG_NO_HZ_FULL 686 atomic_t tick_dep_mask; 687 #endif 688 /* Context switch counts: */ 689 unsigned long nvcsw; 690 unsigned long nivcsw; 691 692 /* Monotonic time in nsecs: */ 693 u64 start_time; 694 695 /* Boot based time in nsecs: */ 696 u64 real_start_time; 697 698 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 699 unsigned long min_flt; 700 unsigned long maj_flt; 701 702 #ifdef CONFIG_POSIX_TIMERS 703 struct task_cputime cputime_expires; 704 struct list_head cpu_timers[3]; 705 #endif 706 707 /* Process credentials: */ 708 709 /* Tracer's credentials at attach: */ 710 const struct cred __rcu *ptracer_cred; 711 712 /* Objective and real subjective task credentials (COW): */ 713 const struct cred __rcu *real_cred; 714 715 /* Effective (overridable) subjective task credentials (COW): */ 716 const struct cred __rcu *cred; 717 718 /* 719 * executable name, excluding path. 720 * 721 * - normally initialized setup_new_exec() 722 * - access it with [gs]et_task_comm() 723 * - lock it with task_lock() 724 */ 725 char comm[TASK_COMM_LEN]; 726 727 struct nameidata *nameidata; 728 729 #ifdef CONFIG_SYSVIPC 730 struct sysv_sem sysvsem; 731 struct sysv_shm sysvshm; 732 #endif 733 #ifdef CONFIG_DETECT_HUNG_TASK 734 unsigned long last_switch_count; 735 #endif 736 /* Filesystem information: */ 737 struct fs_struct *fs; 738 739 /* Open file information: */ 740 struct files_struct *files; 741 742 /* Namespaces: */ 743 struct nsproxy *nsproxy; 744 745 /* Signal handlers: */ 746 struct signal_struct *signal; 747 struct sighand_struct *sighand; 748 sigset_t blocked; 749 sigset_t real_blocked; 750 /* Restored if set_restore_sigmask() was used: */ 751 sigset_t saved_sigmask; 752 struct sigpending pending; 753 unsigned long sas_ss_sp; 754 size_t sas_ss_size; 755 unsigned int sas_ss_flags; 756 757 struct callback_head *task_works; 758 759 struct audit_context *audit_context; 760 #ifdef CONFIG_AUDITSYSCALL 761 kuid_t loginuid; 762 unsigned int sessionid; 763 #endif 764 struct seccomp seccomp; 765 766 /* Thread group tracking: */ 767 u32 parent_exec_id; 768 u32 self_exec_id; 769 770 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 771 spinlock_t alloc_lock; 772 773 /* Protection of the PI data structures: */ 774 raw_spinlock_t pi_lock; 775 776 struct wake_q_node wake_q; 777 778 #ifdef CONFIG_RT_MUTEXES 779 /* PI waiters blocked on a rt_mutex held by this task: */ 780 struct rb_root pi_waiters; 781 struct rb_node *pi_waiters_leftmost; 782 /* Updated under owner's pi_lock and rq lock */ 783 struct task_struct *pi_top_task; 784 /* Deadlock detection and priority inheritance handling: */ 785 struct rt_mutex_waiter *pi_blocked_on; 786 #endif 787 788 #ifdef CONFIG_DEBUG_MUTEXES 789 /* Mutex deadlock detection: */ 790 struct mutex_waiter *blocked_on; 791 #endif 792 793 #ifdef CONFIG_TRACE_IRQFLAGS 794 unsigned int irq_events; 795 unsigned long hardirq_enable_ip; 796 unsigned long hardirq_disable_ip; 797 unsigned int hardirq_enable_event; 798 unsigned int hardirq_disable_event; 799 int hardirqs_enabled; 800 int hardirq_context; 801 unsigned long softirq_disable_ip; 802 unsigned long softirq_enable_ip; 803 unsigned int softirq_disable_event; 804 unsigned int softirq_enable_event; 805 int softirqs_enabled; 806 int softirq_context; 807 #endif 808 809 #ifdef CONFIG_LOCKDEP 810 # define MAX_LOCK_DEPTH 48UL 811 u64 curr_chain_key; 812 int lockdep_depth; 813 unsigned int lockdep_recursion; 814 struct held_lock held_locks[MAX_LOCK_DEPTH]; 815 gfp_t lockdep_reclaim_gfp; 816 #endif 817 818 #ifdef CONFIG_UBSAN 819 unsigned int in_ubsan; 820 #endif 821 822 /* Journalling filesystem info: */ 823 void *journal_info; 824 825 /* Stacked block device info: */ 826 struct bio_list *bio_list; 827 828 #ifdef CONFIG_BLOCK 829 /* Stack plugging: */ 830 struct blk_plug *plug; 831 #endif 832 833 /* VM state: */ 834 struct reclaim_state *reclaim_state; 835 836 struct backing_dev_info *backing_dev_info; 837 838 struct io_context *io_context; 839 840 /* Ptrace state: */ 841 unsigned long ptrace_message; 842 siginfo_t *last_siginfo; 843 844 struct task_io_accounting ioac; 845 #ifdef CONFIG_TASK_XACCT 846 /* Accumulated RSS usage: */ 847 u64 acct_rss_mem1; 848 /* Accumulated virtual memory usage: */ 849 u64 acct_vm_mem1; 850 /* stime + utime since last update: */ 851 u64 acct_timexpd; 852 #endif 853 #ifdef CONFIG_CPUSETS 854 /* Protected by ->alloc_lock: */ 855 nodemask_t mems_allowed; 856 /* Seqence number to catch updates: */ 857 seqcount_t mems_allowed_seq; 858 int cpuset_mem_spread_rotor; 859 int cpuset_slab_spread_rotor; 860 #endif 861 #ifdef CONFIG_CGROUPS 862 /* Control Group info protected by css_set_lock: */ 863 struct css_set __rcu *cgroups; 864 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 865 struct list_head cg_list; 866 #endif 867 #ifdef CONFIG_INTEL_RDT_A 868 int closid; 869 #endif 870 #ifdef CONFIG_FUTEX 871 struct robust_list_head __user *robust_list; 872 #ifdef CONFIG_COMPAT 873 struct compat_robust_list_head __user *compat_robust_list; 874 #endif 875 struct list_head pi_state_list; 876 struct futex_pi_state *pi_state_cache; 877 #endif 878 #ifdef CONFIG_PERF_EVENTS 879 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 880 struct mutex perf_event_mutex; 881 struct list_head perf_event_list; 882 #endif 883 #ifdef CONFIG_DEBUG_PREEMPT 884 unsigned long preempt_disable_ip; 885 #endif 886 #ifdef CONFIG_NUMA 887 /* Protected by alloc_lock: */ 888 struct mempolicy *mempolicy; 889 short il_next; 890 short pref_node_fork; 891 #endif 892 #ifdef CONFIG_NUMA_BALANCING 893 int numa_scan_seq; 894 unsigned int numa_scan_period; 895 unsigned int numa_scan_period_max; 896 int numa_preferred_nid; 897 unsigned long numa_migrate_retry; 898 /* Migration stamp: */ 899 u64 node_stamp; 900 u64 last_task_numa_placement; 901 u64 last_sum_exec_runtime; 902 struct callback_head numa_work; 903 904 struct list_head numa_entry; 905 struct numa_group *numa_group; 906 907 /* 908 * numa_faults is an array split into four regions: 909 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 910 * in this precise order. 911 * 912 * faults_memory: Exponential decaying average of faults on a per-node 913 * basis. Scheduling placement decisions are made based on these 914 * counts. The values remain static for the duration of a PTE scan. 915 * faults_cpu: Track the nodes the process was running on when a NUMA 916 * hinting fault was incurred. 917 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 918 * during the current scan window. When the scan completes, the counts 919 * in faults_memory and faults_cpu decay and these values are copied. 920 */ 921 unsigned long *numa_faults; 922 unsigned long total_numa_faults; 923 924 /* 925 * numa_faults_locality tracks if faults recorded during the last 926 * scan window were remote/local or failed to migrate. The task scan 927 * period is adapted based on the locality of the faults with different 928 * weights depending on whether they were shared or private faults 929 */ 930 unsigned long numa_faults_locality[3]; 931 932 unsigned long numa_pages_migrated; 933 #endif /* CONFIG_NUMA_BALANCING */ 934 935 struct tlbflush_unmap_batch tlb_ubc; 936 937 struct rcu_head rcu; 938 939 /* Cache last used pipe for splice(): */ 940 struct pipe_inode_info *splice_pipe; 941 942 struct page_frag task_frag; 943 944 #ifdef CONFIG_TASK_DELAY_ACCT 945 struct task_delay_info *delays; 946 #endif 947 948 #ifdef CONFIG_FAULT_INJECTION 949 int make_it_fail; 950 #endif 951 /* 952 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 953 * balance_dirty_pages() for a dirty throttling pause: 954 */ 955 int nr_dirtied; 956 int nr_dirtied_pause; 957 /* Start of a write-and-pause period: */ 958 unsigned long dirty_paused_when; 959 960 #ifdef CONFIG_LATENCYTOP 961 int latency_record_count; 962 struct latency_record latency_record[LT_SAVECOUNT]; 963 #endif 964 /* 965 * Time slack values; these are used to round up poll() and 966 * select() etc timeout values. These are in nanoseconds. 967 */ 968 u64 timer_slack_ns; 969 u64 default_timer_slack_ns; 970 971 #ifdef CONFIG_KASAN 972 unsigned int kasan_depth; 973 #endif 974 975 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 976 /* Index of current stored address in ret_stack: */ 977 int curr_ret_stack; 978 979 /* Stack of return addresses for return function tracing: */ 980 struct ftrace_ret_stack *ret_stack; 981 982 /* Timestamp for last schedule: */ 983 unsigned long long ftrace_timestamp; 984 985 /* 986 * Number of functions that haven't been traced 987 * because of depth overrun: 988 */ 989 atomic_t trace_overrun; 990 991 /* Pause tracing: */ 992 atomic_t tracing_graph_pause; 993 #endif 994 995 #ifdef CONFIG_TRACING 996 /* State flags for use by tracers: */ 997 unsigned long trace; 998 999 /* Bitmask and counter of trace recursion: */ 1000 unsigned long trace_recursion; 1001 #endif /* CONFIG_TRACING */ 1002 1003 #ifdef CONFIG_KCOV 1004 /* Coverage collection mode enabled for this task (0 if disabled): */ 1005 enum kcov_mode kcov_mode; 1006 1007 /* Size of the kcov_area: */ 1008 unsigned int kcov_size; 1009 1010 /* Buffer for coverage collection: */ 1011 void *kcov_area; 1012 1013 /* KCOV descriptor wired with this task or NULL: */ 1014 struct kcov *kcov; 1015 #endif 1016 1017 #ifdef CONFIG_MEMCG 1018 struct mem_cgroup *memcg_in_oom; 1019 gfp_t memcg_oom_gfp_mask; 1020 int memcg_oom_order; 1021 1022 /* Number of pages to reclaim on returning to userland: */ 1023 unsigned int memcg_nr_pages_over_high; 1024 #endif 1025 1026 #ifdef CONFIG_UPROBES 1027 struct uprobe_task *utask; 1028 #endif 1029 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1030 unsigned int sequential_io; 1031 unsigned int sequential_io_avg; 1032 #endif 1033 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1034 unsigned long task_state_change; 1035 #endif 1036 int pagefault_disabled; 1037 #ifdef CONFIG_MMU 1038 struct task_struct *oom_reaper_list; 1039 #endif 1040 #ifdef CONFIG_VMAP_STACK 1041 struct vm_struct *stack_vm_area; 1042 #endif 1043 #ifdef CONFIG_THREAD_INFO_IN_TASK 1044 /* A live task holds one reference: */ 1045 atomic_t stack_refcount; 1046 #endif 1047 #ifdef CONFIG_LIVEPATCH 1048 int patch_state; 1049 #endif 1050 #ifdef CONFIG_SECURITY 1051 /* Used by LSM modules for access restriction: */ 1052 void *security; 1053 #endif 1054 /* CPU-specific state of this task: */ 1055 struct thread_struct thread; 1056 1057 /* 1058 * WARNING: on x86, 'thread_struct' contains a variable-sized 1059 * structure. It *MUST* be at the end of 'task_struct'. 1060 * 1061 * Do not put anything below here! 1062 */ 1063 }; 1064 1065 static inline struct pid *task_pid(struct task_struct *task) 1066 { 1067 return task->pids[PIDTYPE_PID].pid; 1068 } 1069 1070 static inline struct pid *task_tgid(struct task_struct *task) 1071 { 1072 return task->group_leader->pids[PIDTYPE_PID].pid; 1073 } 1074 1075 /* 1076 * Without tasklist or RCU lock it is not safe to dereference 1077 * the result of task_pgrp/task_session even if task == current, 1078 * we can race with another thread doing sys_setsid/sys_setpgid. 1079 */ 1080 static inline struct pid *task_pgrp(struct task_struct *task) 1081 { 1082 return task->group_leader->pids[PIDTYPE_PGID].pid; 1083 } 1084 1085 static inline struct pid *task_session(struct task_struct *task) 1086 { 1087 return task->group_leader->pids[PIDTYPE_SID].pid; 1088 } 1089 1090 /* 1091 * the helpers to get the task's different pids as they are seen 1092 * from various namespaces 1093 * 1094 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1095 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1096 * current. 1097 * task_xid_nr_ns() : id seen from the ns specified; 1098 * 1099 * set_task_vxid() : assigns a virtual id to a task; 1100 * 1101 * see also pid_nr() etc in include/linux/pid.h 1102 */ 1103 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1104 1105 static inline pid_t task_pid_nr(struct task_struct *tsk) 1106 { 1107 return tsk->pid; 1108 } 1109 1110 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1111 { 1112 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1113 } 1114 1115 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1116 { 1117 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1118 } 1119 1120 1121 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1122 { 1123 return tsk->tgid; 1124 } 1125 1126 extern pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns); 1127 1128 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1129 { 1130 return pid_vnr(task_tgid(tsk)); 1131 } 1132 1133 /** 1134 * pid_alive - check that a task structure is not stale 1135 * @p: Task structure to be checked. 1136 * 1137 * Test if a process is not yet dead (at most zombie state) 1138 * If pid_alive fails, then pointers within the task structure 1139 * can be stale and must not be dereferenced. 1140 * 1141 * Return: 1 if the process is alive. 0 otherwise. 1142 */ 1143 static inline int pid_alive(const struct task_struct *p) 1144 { 1145 return p->pids[PIDTYPE_PID].pid != NULL; 1146 } 1147 1148 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1149 { 1150 pid_t pid = 0; 1151 1152 rcu_read_lock(); 1153 if (pid_alive(tsk)) 1154 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1155 rcu_read_unlock(); 1156 1157 return pid; 1158 } 1159 1160 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1161 { 1162 return task_ppid_nr_ns(tsk, &init_pid_ns); 1163 } 1164 1165 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1166 { 1167 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1168 } 1169 1170 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1171 { 1172 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1173 } 1174 1175 1176 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1177 { 1178 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1179 } 1180 1181 static inline pid_t task_session_vnr(struct task_struct *tsk) 1182 { 1183 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1184 } 1185 1186 /* Obsolete, do not use: */ 1187 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1188 { 1189 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1190 } 1191 1192 /** 1193 * is_global_init - check if a task structure is init. Since init 1194 * is free to have sub-threads we need to check tgid. 1195 * @tsk: Task structure to be checked. 1196 * 1197 * Check if a task structure is the first user space task the kernel created. 1198 * 1199 * Return: 1 if the task structure is init. 0 otherwise. 1200 */ 1201 static inline int is_global_init(struct task_struct *tsk) 1202 { 1203 return task_tgid_nr(tsk) == 1; 1204 } 1205 1206 extern struct pid *cad_pid; 1207 1208 /* 1209 * Per process flags 1210 */ 1211 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1212 #define PF_EXITING 0x00000004 /* Getting shut down */ 1213 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */ 1214 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ 1215 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1216 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1217 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1218 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1219 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1220 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1221 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1222 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1223 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1224 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */ 1225 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1226 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1227 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1228 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1229 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1230 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */ 1231 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1232 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1233 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ 1234 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */ 1235 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1236 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ 1237 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1238 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1239 1240 /* 1241 * Only the _current_ task can read/write to tsk->flags, but other 1242 * tasks can access tsk->flags in readonly mode for example 1243 * with tsk_used_math (like during threaded core dumping). 1244 * There is however an exception to this rule during ptrace 1245 * or during fork: the ptracer task is allowed to write to the 1246 * child->flags of its traced child (same goes for fork, the parent 1247 * can write to the child->flags), because we're guaranteed the 1248 * child is not running and in turn not changing child->flags 1249 * at the same time the parent does it. 1250 */ 1251 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1252 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1253 #define clear_used_math() clear_stopped_child_used_math(current) 1254 #define set_used_math() set_stopped_child_used_math(current) 1255 1256 #define conditional_stopped_child_used_math(condition, child) \ 1257 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1258 1259 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1260 1261 #define copy_to_stopped_child_used_math(child) \ 1262 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1263 1264 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1265 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1266 #define used_math() tsk_used_math(current) 1267 1268 /* Per-process atomic flags. */ 1269 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1270 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1271 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1272 1273 1274 #define TASK_PFA_TEST(name, func) \ 1275 static inline bool task_##func(struct task_struct *p) \ 1276 { return test_bit(PFA_##name, &p->atomic_flags); } 1277 1278 #define TASK_PFA_SET(name, func) \ 1279 static inline void task_set_##func(struct task_struct *p) \ 1280 { set_bit(PFA_##name, &p->atomic_flags); } 1281 1282 #define TASK_PFA_CLEAR(name, func) \ 1283 static inline void task_clear_##func(struct task_struct *p) \ 1284 { clear_bit(PFA_##name, &p->atomic_flags); } 1285 1286 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1287 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1288 1289 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1290 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1291 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1292 1293 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1294 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1295 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1296 1297 static inline void 1298 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1299 { 1300 current->flags &= ~flags; 1301 current->flags |= orig_flags & flags; 1302 } 1303 1304 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1305 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); 1306 #ifdef CONFIG_SMP 1307 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1308 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1309 #else 1310 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1311 { 1312 } 1313 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1314 { 1315 if (!cpumask_test_cpu(0, new_mask)) 1316 return -EINVAL; 1317 return 0; 1318 } 1319 #endif 1320 1321 #ifndef cpu_relax_yield 1322 #define cpu_relax_yield() cpu_relax() 1323 #endif 1324 1325 extern int yield_to(struct task_struct *p, bool preempt); 1326 extern void set_user_nice(struct task_struct *p, long nice); 1327 extern int task_prio(const struct task_struct *p); 1328 1329 /** 1330 * task_nice - return the nice value of a given task. 1331 * @p: the task in question. 1332 * 1333 * Return: The nice value [ -20 ... 0 ... 19 ]. 1334 */ 1335 static inline int task_nice(const struct task_struct *p) 1336 { 1337 return PRIO_TO_NICE((p)->static_prio); 1338 } 1339 1340 extern int can_nice(const struct task_struct *p, const int nice); 1341 extern int task_curr(const struct task_struct *p); 1342 extern int idle_cpu(int cpu); 1343 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1344 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1345 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1346 extern struct task_struct *idle_task(int cpu); 1347 1348 /** 1349 * is_idle_task - is the specified task an idle task? 1350 * @p: the task in question. 1351 * 1352 * Return: 1 if @p is an idle task. 0 otherwise. 1353 */ 1354 static inline bool is_idle_task(const struct task_struct *p) 1355 { 1356 return !!(p->flags & PF_IDLE); 1357 } 1358 1359 extern struct task_struct *curr_task(int cpu); 1360 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1361 1362 void yield(void); 1363 1364 union thread_union { 1365 #ifndef CONFIG_THREAD_INFO_IN_TASK 1366 struct thread_info thread_info; 1367 #endif 1368 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1369 }; 1370 1371 #ifdef CONFIG_THREAD_INFO_IN_TASK 1372 static inline struct thread_info *task_thread_info(struct task_struct *task) 1373 { 1374 return &task->thread_info; 1375 } 1376 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1377 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1378 #endif 1379 1380 /* 1381 * find a task by one of its numerical ids 1382 * 1383 * find_task_by_pid_ns(): 1384 * finds a task by its pid in the specified namespace 1385 * find_task_by_vpid(): 1386 * finds a task by its virtual pid 1387 * 1388 * see also find_vpid() etc in include/linux/pid.h 1389 */ 1390 1391 extern struct task_struct *find_task_by_vpid(pid_t nr); 1392 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1393 1394 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1395 extern int wake_up_process(struct task_struct *tsk); 1396 extern void wake_up_new_task(struct task_struct *tsk); 1397 1398 #ifdef CONFIG_SMP 1399 extern void kick_process(struct task_struct *tsk); 1400 #else 1401 static inline void kick_process(struct task_struct *tsk) { } 1402 #endif 1403 1404 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1405 1406 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1407 { 1408 __set_task_comm(tsk, from, false); 1409 } 1410 1411 extern char *get_task_comm(char *to, struct task_struct *tsk); 1412 1413 #ifdef CONFIG_SMP 1414 void scheduler_ipi(void); 1415 extern unsigned long wait_task_inactive(struct task_struct *, long match_state); 1416 #else 1417 static inline void scheduler_ipi(void) { } 1418 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state) 1419 { 1420 return 1; 1421 } 1422 #endif 1423 1424 /* 1425 * Set thread flags in other task's structures. 1426 * See asm/thread_info.h for TIF_xxxx flags available: 1427 */ 1428 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1429 { 1430 set_ti_thread_flag(task_thread_info(tsk), flag); 1431 } 1432 1433 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1434 { 1435 clear_ti_thread_flag(task_thread_info(tsk), flag); 1436 } 1437 1438 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1439 { 1440 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1441 } 1442 1443 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1444 { 1445 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1446 } 1447 1448 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1449 { 1450 return test_ti_thread_flag(task_thread_info(tsk), flag); 1451 } 1452 1453 static inline void set_tsk_need_resched(struct task_struct *tsk) 1454 { 1455 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1456 } 1457 1458 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1459 { 1460 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1461 } 1462 1463 static inline int test_tsk_need_resched(struct task_struct *tsk) 1464 { 1465 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 1466 } 1467 1468 /* 1469 * cond_resched() and cond_resched_lock(): latency reduction via 1470 * explicit rescheduling in places that are safe. The return 1471 * value indicates whether a reschedule was done in fact. 1472 * cond_resched_lock() will drop the spinlock before scheduling, 1473 * cond_resched_softirq() will enable bhs before scheduling. 1474 */ 1475 #ifndef CONFIG_PREEMPT 1476 extern int _cond_resched(void); 1477 #else 1478 static inline int _cond_resched(void) { return 0; } 1479 #endif 1480 1481 #define cond_resched() ({ \ 1482 ___might_sleep(__FILE__, __LINE__, 0); \ 1483 _cond_resched(); \ 1484 }) 1485 1486 extern int __cond_resched_lock(spinlock_t *lock); 1487 1488 #define cond_resched_lock(lock) ({ \ 1489 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\ 1490 __cond_resched_lock(lock); \ 1491 }) 1492 1493 extern int __cond_resched_softirq(void); 1494 1495 #define cond_resched_softirq() ({ \ 1496 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \ 1497 __cond_resched_softirq(); \ 1498 }) 1499 1500 static inline void cond_resched_rcu(void) 1501 { 1502 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 1503 rcu_read_unlock(); 1504 cond_resched(); 1505 rcu_read_lock(); 1506 #endif 1507 } 1508 1509 /* 1510 * Does a critical section need to be broken due to another 1511 * task waiting?: (technically does not depend on CONFIG_PREEMPT, 1512 * but a general need for low latency) 1513 */ 1514 static inline int spin_needbreak(spinlock_t *lock) 1515 { 1516 #ifdef CONFIG_PREEMPT 1517 return spin_is_contended(lock); 1518 #else 1519 return 0; 1520 #endif 1521 } 1522 1523 static __always_inline bool need_resched(void) 1524 { 1525 return unlikely(tif_need_resched()); 1526 } 1527 1528 /* 1529 * Wrappers for p->thread_info->cpu access. No-op on UP. 1530 */ 1531 #ifdef CONFIG_SMP 1532 1533 static inline unsigned int task_cpu(const struct task_struct *p) 1534 { 1535 #ifdef CONFIG_THREAD_INFO_IN_TASK 1536 return p->cpu; 1537 #else 1538 return task_thread_info(p)->cpu; 1539 #endif 1540 } 1541 1542 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 1543 1544 #else 1545 1546 static inline unsigned int task_cpu(const struct task_struct *p) 1547 { 1548 return 0; 1549 } 1550 1551 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 1552 { 1553 } 1554 1555 #endif /* CONFIG_SMP */ 1556 1557 /* 1558 * In order to reduce various lock holder preemption latencies provide an 1559 * interface to see if a vCPU is currently running or not. 1560 * 1561 * This allows us to terminate optimistic spin loops and block, analogous to 1562 * the native optimistic spin heuristic of testing if the lock owner task is 1563 * running or not. 1564 */ 1565 #ifndef vcpu_is_preempted 1566 # define vcpu_is_preempted(cpu) false 1567 #endif 1568 1569 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 1570 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 1571 1572 #ifndef TASK_SIZE_OF 1573 #define TASK_SIZE_OF(tsk) TASK_SIZE 1574 #endif 1575 1576 #endif 1577