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