1 /* SPDX-License-Identifier: GPL-2.0 */
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
10 #include <uapi/linux/sched.h>
12 #include <asm/current.h>
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kcov.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/seccomp.h>
22 #include <linux/nodemask.h>
23 #include <linux/rcupdate.h>
24 #include <linux/resource.h>
25 #include <linux/latencytop.h>
26 #include <linux/sched/prio.h>
27 #include <linux/signal_types.h>
28 #include <linux/mm_types_task.h>
29 #include <linux/task_io_accounting.h>
31 /* task_struct member predeclarations (sorted alphabetically): */
33 struct backing_dev_info;
38 struct futex_pi_state;
43 struct perf_event_context;
45 struct pipe_inode_info;
48 struct robust_list_head;
52 struct sighand_struct;
54 struct task_delay_info;
58 * Task state bitmask. NOTE! These bits are also
59 * encoded in fs/proc/array.c: get_task_state().
61 * We have two separate sets of flags: task->state
62 * is about runnability, while task->exit_state are
63 * about the task exiting. Confusing, but this way
64 * modifying one set can't modify the other one by
68 /* Used in tsk->state: */
69 #define TASK_RUNNING 0x0000
70 #define TASK_INTERRUPTIBLE 0x0001
71 #define TASK_UNINTERRUPTIBLE 0x0002
72 #define __TASK_STOPPED 0x0004
73 #define __TASK_TRACED 0x0008
74 /* Used in tsk->exit_state: */
75 #define EXIT_DEAD 0x0010
76 #define EXIT_ZOMBIE 0x0020
77 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
78 /* Used in tsk->state again: */
79 #define TASK_PARKED 0x0040
80 #define TASK_DEAD 0x0080
81 #define TASK_WAKEKILL 0x0100
82 #define TASK_WAKING 0x0200
83 #define TASK_NOLOAD 0x0400
84 #define TASK_NEW 0x0800
85 #define TASK_STATE_MAX 0x1000
87 /* Convenience macros for the sake of set_current_state: */
88 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
89 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
90 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
92 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
94 /* Convenience macros for the sake of wake_up(): */
95 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
97 /* get_task_state(): */
98 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
99 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
100 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
103 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
105 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
107 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
109 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
110 (task->flags & PF_FROZEN) == 0 && \
111 (task->state & TASK_NOLOAD) == 0)
113 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
115 #define __set_current_state(state_value) \
117 current->task_state_change = _THIS_IP_; \
118 current->state = (state_value); \
120 #define set_current_state(state_value) \
122 current->task_state_change = _THIS_IP_; \
123 smp_store_mb(current->state, (state_value)); \
128 * set_current_state() includes a barrier so that the write of current->state
129 * is correctly serialised wrt the caller's subsequent test of whether to
133 * set_current_state(TASK_UNINTERRUPTIBLE);
139 * __set_current_state(TASK_RUNNING);
141 * If the caller does not need such serialisation (because, for instance, the
142 * condition test and condition change and wakeup are under the same lock) then
143 * use __set_current_state().
145 * The above is typically ordered against the wakeup, which does:
147 * need_sleep = false;
148 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
150 * Where wake_up_state() (and all other wakeup primitives) imply enough
151 * barriers to order the store of the variable against wakeup.
153 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
154 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
155 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
157 * This is obviously fine, since they both store the exact same value.
159 * Also see the comments of try_to_wake_up().
161 #define __set_current_state(state_value) do { current->state = (state_value); } while (0)
162 #define set_current_state(state_value) smp_store_mb(current->state, (state_value))
165 /* Task command name length: */
166 #define TASK_COMM_LEN 16
168 extern void scheduler_tick(void);
170 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
172 extern long schedule_timeout(long timeout);
173 extern long schedule_timeout_interruptible(long timeout);
174 extern long schedule_timeout_killable(long timeout);
175 extern long schedule_timeout_uninterruptible(long timeout);
176 extern long schedule_timeout_idle(long timeout);
177 asmlinkage void schedule(void);
178 extern void schedule_preempt_disabled(void);
180 extern int __must_check io_schedule_prepare(void);
181 extern void io_schedule_finish(int token);
182 extern long io_schedule_timeout(long timeout);
183 extern void io_schedule(void);
186 * struct prev_cputime - snapshot of system and user cputime
187 * @utime: time spent in user mode
188 * @stime: time spent in system mode
189 * @lock: protects the above two fields
191 * Stores previous user/system time values such that we can guarantee
194 struct prev_cputime {
195 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
203 * struct task_cputime - collected CPU time counts
204 * @utime: time spent in user mode, in nanoseconds
205 * @stime: time spent in kernel mode, in nanoseconds
206 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
208 * This structure groups together three kinds of CPU time that are tracked for
209 * threads and thread groups. Most things considering CPU time want to group
210 * these counts together and treat all three of them in parallel.
212 struct task_cputime {
215 unsigned long long sum_exec_runtime;
218 /* Alternate field names when used on cache expirations: */
219 #define virt_exp utime
220 #define prof_exp stime
221 #define sched_exp sum_exec_runtime
224 /* Task is sleeping or running in a CPU with VTIME inactive: */
226 /* Task runs in userspace in a CPU with VTIME active: */
228 /* Task runs in kernelspace in a CPU with VTIME active: */
234 unsigned long long starttime;
235 enum vtime_state state;
242 #ifdef CONFIG_SCHED_INFO
243 /* Cumulative counters: */
245 /* # of times we have run on this CPU: */
246 unsigned long pcount;
248 /* Time spent waiting on a runqueue: */
249 unsigned long long run_delay;
253 /* When did we last run on a CPU? */
254 unsigned long long last_arrival;
256 /* When were we last queued to run? */
257 unsigned long long last_queued;
259 #endif /* CONFIG_SCHED_INFO */
263 * Integer metrics need fixed point arithmetic, e.g., sched/fair
264 * has a few: load, load_avg, util_avg, freq, and capacity.
266 * We define a basic fixed point arithmetic range, and then formalize
267 * all these metrics based on that basic range.
269 # define SCHED_FIXEDPOINT_SHIFT 10
270 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
273 unsigned long weight;
278 * struct util_est - Estimation utilization of FAIR tasks
279 * @enqueued: instantaneous estimated utilization of a task/cpu
280 * @ewma: the Exponential Weighted Moving Average (EWMA)
281 * utilization of a task
283 * Support data structure to track an Exponential Weighted Moving Average
284 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
285 * average each time a task completes an activation. Sample's weight is chosen
286 * so that the EWMA will be relatively insensitive to transient changes to the
289 * The enqueued attribute has a slightly different meaning for tasks and cpus:
290 * - task: the task's util_avg at last task dequeue time
291 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
292 * Thus, the util_est.enqueued of a task represents the contribution on the
293 * estimated utilization of the CPU where that task is currently enqueued.
295 * Only for tasks we track a moving average of the past instantaneous
296 * estimated utilization. This allows to absorb sporadic drops in utilization
297 * of an otherwise almost periodic task.
300 unsigned int enqueued;
302 #define UTIL_EST_WEIGHT_SHIFT 2
306 * The load_avg/util_avg accumulates an infinite geometric series
307 * (see __update_load_avg() in kernel/sched/fair.c).
309 * [load_avg definition]
311 * load_avg = runnable% * scale_load_down(load)
313 * where runnable% is the time ratio that a sched_entity is runnable.
314 * For cfs_rq, it is the aggregated load_avg of all runnable and
315 * blocked sched_entities.
317 * load_avg may also take frequency scaling into account:
319 * load_avg = runnable% * scale_load_down(load) * freq%
321 * where freq% is the CPU frequency normalized to the highest frequency.
323 * [util_avg definition]
325 * util_avg = running% * SCHED_CAPACITY_SCALE
327 * where running% is the time ratio that a sched_entity is running on
328 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
329 * and blocked sched_entities.
331 * util_avg may also factor frequency scaling and CPU capacity scaling:
333 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
335 * where freq% is the same as above, and capacity% is the CPU capacity
336 * normalized to the greatest capacity (due to uarch differences, etc).
338 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
339 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
340 * we therefore scale them to as large a range as necessary. This is for
341 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
345 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
346 * with the highest load (=88761), always runnable on a single cfs_rq,
347 * and should not overflow as the number already hits PID_MAX_LIMIT.
349 * For all other cases (including 32-bit kernels), struct load_weight's
350 * weight will overflow first before we do, because:
352 * Max(load_avg) <= Max(load.weight)
354 * Then it is the load_weight's responsibility to consider overflow
358 u64 last_update_time;
360 u64 runnable_load_sum;
363 unsigned long load_avg;
364 unsigned long runnable_load_avg;
365 unsigned long util_avg;
366 struct util_est util_est;
369 struct sched_statistics {
370 #ifdef CONFIG_SCHEDSTATS
380 s64 sum_sleep_runtime;
387 u64 nr_migrations_cold;
388 u64 nr_failed_migrations_affine;
389 u64 nr_failed_migrations_running;
390 u64 nr_failed_migrations_hot;
391 u64 nr_forced_migrations;
395 u64 nr_wakeups_migrate;
396 u64 nr_wakeups_local;
397 u64 nr_wakeups_remote;
398 u64 nr_wakeups_affine;
399 u64 nr_wakeups_affine_attempts;
400 u64 nr_wakeups_passive;
405 struct sched_entity {
406 /* For load-balancing: */
407 struct load_weight load;
408 unsigned long runnable_weight;
409 struct rb_node run_node;
410 struct list_head group_node;
414 u64 sum_exec_runtime;
416 u64 prev_sum_exec_runtime;
420 struct sched_statistics statistics;
422 #ifdef CONFIG_FAIR_GROUP_SCHED
424 struct sched_entity *parent;
425 /* rq on which this entity is (to be) queued: */
426 struct cfs_rq *cfs_rq;
427 /* rq "owned" by this entity/group: */
433 * Per entity load average tracking.
435 * Put into separate cache line so it does not
436 * collide with read-mostly values above.
438 struct sched_avg avg ____cacheline_aligned_in_smp;
442 struct sched_rt_entity {
443 struct list_head run_list;
444 unsigned long timeout;
445 unsigned long watchdog_stamp;
446 unsigned int time_slice;
447 unsigned short on_rq;
448 unsigned short on_list;
450 struct sched_rt_entity *back;
451 #ifdef CONFIG_RT_GROUP_SCHED
452 struct sched_rt_entity *parent;
453 /* rq on which this entity is (to be) queued: */
455 /* rq "owned" by this entity/group: */
458 } __randomize_layout;
460 struct sched_dl_entity {
461 struct rb_node rb_node;
464 * Original scheduling parameters. Copied here from sched_attr
465 * during sched_setattr(), they will remain the same until
466 * the next sched_setattr().
468 u64 dl_runtime; /* Maximum runtime for each instance */
469 u64 dl_deadline; /* Relative deadline of each instance */
470 u64 dl_period; /* Separation of two instances (period) */
471 u64 dl_bw; /* dl_runtime / dl_period */
472 u64 dl_density; /* dl_runtime / dl_deadline */
475 * Actual scheduling parameters. Initialized with the values above,
476 * they are continously updated during task execution. Note that
477 * the remaining runtime could be < 0 in case we are in overrun.
479 s64 runtime; /* Remaining runtime for this instance */
480 u64 deadline; /* Absolute deadline for this instance */
481 unsigned int flags; /* Specifying the scheduler behaviour */
486 * @dl_throttled tells if we exhausted the runtime. If so, the
487 * task has to wait for a replenishment to be performed at the
488 * next firing of dl_timer.
490 * @dl_boosted tells if we are boosted due to DI. If so we are
491 * outside bandwidth enforcement mechanism (but only until we
492 * exit the critical section);
494 * @dl_yielded tells if task gave up the CPU before consuming
495 * all its available runtime during the last job.
497 * @dl_non_contending tells if the task is inactive while still
498 * contributing to the active utilization. In other words, it
499 * indicates if the inactive timer has been armed and its handler
500 * has not been executed yet. This flag is useful to avoid race
501 * conditions between the inactive timer handler and the wakeup
504 * @dl_overrun tells if the task asked to be informed about runtime
507 unsigned int dl_throttled : 1;
508 unsigned int dl_boosted : 1;
509 unsigned int dl_yielded : 1;
510 unsigned int dl_non_contending : 1;
511 unsigned int dl_overrun : 1;
514 * Bandwidth enforcement timer. Each -deadline task has its
515 * own bandwidth to be enforced, thus we need one timer per task.
517 struct hrtimer dl_timer;
520 * Inactive timer, responsible for decreasing the active utilization
521 * at the "0-lag time". When a -deadline task blocks, it contributes
522 * to GRUB's active utilization until the "0-lag time", hence a
523 * timer is needed to decrease the active utilization at the correct
526 struct hrtimer inactive_timer;
535 /* Otherwise the compiler can store garbage here: */
538 u32 s; /* Set of bits. */
541 enum perf_event_task_context {
542 perf_invalid_context = -1,
545 perf_nr_task_contexts,
549 struct wake_q_node *next;
553 #ifdef CONFIG_THREAD_INFO_IN_TASK
555 * For reasons of header soup (see current_thread_info()), this
556 * must be the first element of task_struct.
558 struct thread_info thread_info;
560 /* -1 unrunnable, 0 runnable, >0 stopped: */
564 * This begins the randomizable portion of task_struct. Only
565 * scheduling-critical items should be added above here.
567 randomized_struct_fields_start
571 /* Per task flags (PF_*), defined further below: */
576 struct llist_node wake_entry;
578 #ifdef CONFIG_THREAD_INFO_IN_TASK
582 unsigned int wakee_flips;
583 unsigned long wakee_flip_decay_ts;
584 struct task_struct *last_wakee;
587 * recent_used_cpu is initially set as the last CPU used by a task
588 * that wakes affine another task. Waker/wakee relationships can
589 * push tasks around a CPU where each wakeup moves to the next one.
590 * Tracking a recently used CPU allows a quick search for a recently
591 * used CPU that may be idle.
601 unsigned int rt_priority;
603 const struct sched_class *sched_class;
604 struct sched_entity se;
605 struct sched_rt_entity rt;
606 #ifdef CONFIG_CGROUP_SCHED
607 struct task_group *sched_task_group;
609 struct sched_dl_entity dl;
611 #ifdef CONFIG_PREEMPT_NOTIFIERS
612 /* List of struct preempt_notifier: */
613 struct hlist_head preempt_notifiers;
616 #ifdef CONFIG_BLK_DEV_IO_TRACE
617 unsigned int btrace_seq;
622 cpumask_t cpus_allowed;
624 #ifdef CONFIG_PREEMPT_RCU
625 int rcu_read_lock_nesting;
626 union rcu_special rcu_read_unlock_special;
627 struct list_head rcu_node_entry;
628 struct rcu_node *rcu_blocked_node;
629 #endif /* #ifdef CONFIG_PREEMPT_RCU */
631 #ifdef CONFIG_TASKS_RCU
632 unsigned long rcu_tasks_nvcsw;
633 u8 rcu_tasks_holdout;
635 int rcu_tasks_idle_cpu;
636 struct list_head rcu_tasks_holdout_list;
637 #endif /* #ifdef CONFIG_TASKS_RCU */
639 struct sched_info sched_info;
641 struct list_head tasks;
643 struct plist_node pushable_tasks;
644 struct rb_node pushable_dl_tasks;
647 struct mm_struct *mm;
648 struct mm_struct *active_mm;
650 /* Per-thread vma caching: */
651 struct vmacache vmacache;
653 #ifdef SPLIT_RSS_COUNTING
654 struct task_rss_stat rss_stat;
659 /* The signal sent when the parent dies: */
661 /* JOBCTL_*, siglock protected: */
662 unsigned long jobctl;
664 /* Used for emulating ABI behavior of previous Linux versions: */
665 unsigned int personality;
667 /* Scheduler bits, serialized by scheduler locks: */
668 unsigned sched_reset_on_fork:1;
669 unsigned sched_contributes_to_load:1;
670 unsigned sched_migrated:1;
671 unsigned sched_remote_wakeup:1;
672 /* Force alignment to the next boundary: */
675 /* Unserialized, strictly 'current' */
677 /* Bit to tell LSMs we're in execve(): */
678 unsigned in_execve:1;
679 unsigned in_iowait:1;
680 #ifndef TIF_RESTORE_SIGMASK
681 unsigned restore_sigmask:1;
684 unsigned memcg_may_oom:1;
686 unsigned memcg_kmem_skip_account:1;
689 #ifdef CONFIG_COMPAT_BRK
690 unsigned brk_randomized:1;
692 #ifdef CONFIG_CGROUPS
693 /* disallow userland-initiated cgroup migration */
694 unsigned no_cgroup_migration:1;
697 unsigned long atomic_flags; /* Flags requiring atomic access. */
699 struct restart_block restart_block;
704 #ifdef CONFIG_CC_STACKPROTECTOR
705 /* Canary value for the -fstack-protector GCC feature: */
706 unsigned long stack_canary;
709 * Pointers to the (original) parent process, youngest child, younger sibling,
710 * older sibling, respectively. (p->father can be replaced with
711 * p->real_parent->pid)
714 /* Real parent process: */
715 struct task_struct __rcu *real_parent;
717 /* Recipient of SIGCHLD, wait4() reports: */
718 struct task_struct __rcu *parent;
721 * Children/sibling form the list of natural children:
723 struct list_head children;
724 struct list_head sibling;
725 struct task_struct *group_leader;
728 * 'ptraced' is the list of tasks this task is using ptrace() on.
730 * This includes both natural children and PTRACE_ATTACH targets.
731 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
733 struct list_head ptraced;
734 struct list_head ptrace_entry;
736 /* PID/PID hash table linkage. */
737 struct pid_link pids[PIDTYPE_MAX];
738 struct list_head thread_group;
739 struct list_head thread_node;
741 struct completion *vfork_done;
743 /* CLONE_CHILD_SETTID: */
744 int __user *set_child_tid;
746 /* CLONE_CHILD_CLEARTID: */
747 int __user *clear_child_tid;
751 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
756 struct prev_cputime prev_cputime;
757 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
761 #ifdef CONFIG_NO_HZ_FULL
762 atomic_t tick_dep_mask;
764 /* Context switch counts: */
766 unsigned long nivcsw;
768 /* Monotonic time in nsecs: */
771 /* Boot based time in nsecs: */
774 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
775 unsigned long min_flt;
776 unsigned long maj_flt;
778 #ifdef CONFIG_POSIX_TIMERS
779 struct task_cputime cputime_expires;
780 struct list_head cpu_timers[3];
783 /* Process credentials: */
785 /* Tracer's credentials at attach: */
786 const struct cred __rcu *ptracer_cred;
788 /* Objective and real subjective task credentials (COW): */
789 const struct cred __rcu *real_cred;
791 /* Effective (overridable) subjective task credentials (COW): */
792 const struct cred __rcu *cred;
795 * executable name, excluding path.
797 * - normally initialized setup_new_exec()
798 * - access it with [gs]et_task_comm()
799 * - lock it with task_lock()
801 char comm[TASK_COMM_LEN];
803 struct nameidata *nameidata;
805 #ifdef CONFIG_SYSVIPC
806 struct sysv_sem sysvsem;
807 struct sysv_shm sysvshm;
809 #ifdef CONFIG_DETECT_HUNG_TASK
810 unsigned long last_switch_count;
812 /* Filesystem information: */
813 struct fs_struct *fs;
815 /* Open file information: */
816 struct files_struct *files;
819 struct nsproxy *nsproxy;
821 /* Signal handlers: */
822 struct signal_struct *signal;
823 struct sighand_struct *sighand;
825 sigset_t real_blocked;
826 /* Restored if set_restore_sigmask() was used: */
827 sigset_t saved_sigmask;
828 struct sigpending pending;
829 unsigned long sas_ss_sp;
831 unsigned int sas_ss_flags;
833 struct callback_head *task_works;
835 struct audit_context *audit_context;
836 #ifdef CONFIG_AUDITSYSCALL
838 unsigned int sessionid;
840 struct seccomp seccomp;
842 /* Thread group tracking: */
846 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
847 spinlock_t alloc_lock;
849 /* Protection of the PI data structures: */
850 raw_spinlock_t pi_lock;
852 struct wake_q_node wake_q;
854 #ifdef CONFIG_RT_MUTEXES
855 /* PI waiters blocked on a rt_mutex held by this task: */
856 struct rb_root_cached pi_waiters;
857 /* Updated under owner's pi_lock and rq lock */
858 struct task_struct *pi_top_task;
859 /* Deadlock detection and priority inheritance handling: */
860 struct rt_mutex_waiter *pi_blocked_on;
863 #ifdef CONFIG_DEBUG_MUTEXES
864 /* Mutex deadlock detection: */
865 struct mutex_waiter *blocked_on;
868 #ifdef CONFIG_TRACE_IRQFLAGS
869 unsigned int irq_events;
870 unsigned long hardirq_enable_ip;
871 unsigned long hardirq_disable_ip;
872 unsigned int hardirq_enable_event;
873 unsigned int hardirq_disable_event;
874 int hardirqs_enabled;
876 unsigned long softirq_disable_ip;
877 unsigned long softirq_enable_ip;
878 unsigned int softirq_disable_event;
879 unsigned int softirq_enable_event;
880 int softirqs_enabled;
884 #ifdef CONFIG_LOCKDEP
885 # define MAX_LOCK_DEPTH 48UL
888 unsigned int lockdep_recursion;
889 struct held_lock held_locks[MAX_LOCK_DEPTH];
893 unsigned int in_ubsan;
896 /* Journalling filesystem info: */
899 /* Stacked block device info: */
900 struct bio_list *bio_list;
903 /* Stack plugging: */
904 struct blk_plug *plug;
908 struct reclaim_state *reclaim_state;
910 struct backing_dev_info *backing_dev_info;
912 struct io_context *io_context;
915 unsigned long ptrace_message;
916 siginfo_t *last_siginfo;
918 struct task_io_accounting ioac;
919 #ifdef CONFIG_TASK_XACCT
920 /* Accumulated RSS usage: */
922 /* Accumulated virtual memory usage: */
924 /* stime + utime since last update: */
927 #ifdef CONFIG_CPUSETS
928 /* Protected by ->alloc_lock: */
929 nodemask_t mems_allowed;
930 /* Seqence number to catch updates: */
931 seqcount_t mems_allowed_seq;
932 int cpuset_mem_spread_rotor;
933 int cpuset_slab_spread_rotor;
935 #ifdef CONFIG_CGROUPS
936 /* Control Group info protected by css_set_lock: */
937 struct css_set __rcu *cgroups;
938 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
939 struct list_head cg_list;
941 #ifdef CONFIG_INTEL_RDT
946 struct robust_list_head __user *robust_list;
948 struct compat_robust_list_head __user *compat_robust_list;
950 struct list_head pi_state_list;
951 struct futex_pi_state *pi_state_cache;
953 #ifdef CONFIG_PERF_EVENTS
954 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
955 struct mutex perf_event_mutex;
956 struct list_head perf_event_list;
958 #ifdef CONFIG_DEBUG_PREEMPT
959 unsigned long preempt_disable_ip;
962 /* Protected by alloc_lock: */
963 struct mempolicy *mempolicy;
965 short pref_node_fork;
967 #ifdef CONFIG_NUMA_BALANCING
969 unsigned int numa_scan_period;
970 unsigned int numa_scan_period_max;
971 int numa_preferred_nid;
972 unsigned long numa_migrate_retry;
973 /* Migration stamp: */
975 u64 last_task_numa_placement;
976 u64 last_sum_exec_runtime;
977 struct callback_head numa_work;
979 struct list_head numa_entry;
980 struct numa_group *numa_group;
983 * numa_faults is an array split into four regions:
984 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
985 * in this precise order.
987 * faults_memory: Exponential decaying average of faults on a per-node
988 * basis. Scheduling placement decisions are made based on these
989 * counts. The values remain static for the duration of a PTE scan.
990 * faults_cpu: Track the nodes the process was running on when a NUMA
991 * hinting fault was incurred.
992 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
993 * during the current scan window. When the scan completes, the counts
994 * in faults_memory and faults_cpu decay and these values are copied.
996 unsigned long *numa_faults;
997 unsigned long total_numa_faults;
1000 * numa_faults_locality tracks if faults recorded during the last
1001 * scan window were remote/local or failed to migrate. The task scan
1002 * period is adapted based on the locality of the faults with different
1003 * weights depending on whether they were shared or private faults
1005 unsigned long numa_faults_locality[3];
1007 unsigned long numa_pages_migrated;
1008 #endif /* CONFIG_NUMA_BALANCING */
1010 struct tlbflush_unmap_batch tlb_ubc;
1012 struct rcu_head rcu;
1014 /* Cache last used pipe for splice(): */
1015 struct pipe_inode_info *splice_pipe;
1017 struct page_frag task_frag;
1019 #ifdef CONFIG_TASK_DELAY_ACCT
1020 struct task_delay_info *delays;
1023 #ifdef CONFIG_FAULT_INJECTION
1025 unsigned int fail_nth;
1028 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1029 * balance_dirty_pages() for a dirty throttling pause:
1032 int nr_dirtied_pause;
1033 /* Start of a write-and-pause period: */
1034 unsigned long dirty_paused_when;
1036 #ifdef CONFIG_LATENCYTOP
1037 int latency_record_count;
1038 struct latency_record latency_record[LT_SAVECOUNT];
1041 * Time slack values; these are used to round up poll() and
1042 * select() etc timeout values. These are in nanoseconds.
1045 u64 default_timer_slack_ns;
1048 unsigned int kasan_depth;
1051 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1052 /* Index of current stored address in ret_stack: */
1055 /* Stack of return addresses for return function tracing: */
1056 struct ftrace_ret_stack *ret_stack;
1058 /* Timestamp for last schedule: */
1059 unsigned long long ftrace_timestamp;
1062 * Number of functions that haven't been traced
1063 * because of depth overrun:
1065 atomic_t trace_overrun;
1067 /* Pause tracing: */
1068 atomic_t tracing_graph_pause;
1071 #ifdef CONFIG_TRACING
1072 /* State flags for use by tracers: */
1073 unsigned long trace;
1075 /* Bitmask and counter of trace recursion: */
1076 unsigned long trace_recursion;
1077 #endif /* CONFIG_TRACING */
1080 /* Coverage collection mode enabled for this task (0 if disabled): */
1081 enum kcov_mode kcov_mode;
1083 /* Size of the kcov_area: */
1084 unsigned int kcov_size;
1086 /* Buffer for coverage collection: */
1089 /* KCOV descriptor wired with this task or NULL: */
1094 struct mem_cgroup *memcg_in_oom;
1095 gfp_t memcg_oom_gfp_mask;
1096 int memcg_oom_order;
1098 /* Number of pages to reclaim on returning to userland: */
1099 unsigned int memcg_nr_pages_over_high;
1102 #ifdef CONFIG_UPROBES
1103 struct uprobe_task *utask;
1105 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1106 unsigned int sequential_io;
1107 unsigned int sequential_io_avg;
1109 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1110 unsigned long task_state_change;
1112 int pagefault_disabled;
1114 struct task_struct *oom_reaper_list;
1116 #ifdef CONFIG_VMAP_STACK
1117 struct vm_struct *stack_vm_area;
1119 #ifdef CONFIG_THREAD_INFO_IN_TASK
1120 /* A live task holds one reference: */
1121 atomic_t stack_refcount;
1123 #ifdef CONFIG_LIVEPATCH
1126 #ifdef CONFIG_SECURITY
1127 /* Used by LSM modules for access restriction: */
1132 * New fields for task_struct should be added above here, so that
1133 * they are included in the randomized portion of task_struct.
1135 randomized_struct_fields_end
1137 /* CPU-specific state of this task: */
1138 struct thread_struct thread;
1141 * WARNING: on x86, 'thread_struct' contains a variable-sized
1142 * structure. It *MUST* be at the end of 'task_struct'.
1144 * Do not put anything below here!
1148 static inline struct pid *task_pid(struct task_struct *task)
1150 return task->pids[PIDTYPE_PID].pid;
1153 static inline struct pid *task_tgid(struct task_struct *task)
1155 return task->group_leader->pids[PIDTYPE_PID].pid;
1159 * Without tasklist or RCU lock it is not safe to dereference
1160 * the result of task_pgrp/task_session even if task == current,
1161 * we can race with another thread doing sys_setsid/sys_setpgid.
1163 static inline struct pid *task_pgrp(struct task_struct *task)
1165 return task->group_leader->pids[PIDTYPE_PGID].pid;
1168 static inline struct pid *task_session(struct task_struct *task)
1170 return task->group_leader->pids[PIDTYPE_SID].pid;
1174 * the helpers to get the task's different pids as they are seen
1175 * from various namespaces
1177 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1178 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1180 * task_xid_nr_ns() : id seen from the ns specified;
1182 * see also pid_nr() etc in include/linux/pid.h
1184 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1186 static inline pid_t task_pid_nr(struct task_struct *tsk)
1191 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1193 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1196 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1198 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1202 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1208 * pid_alive - check that a task structure is not stale
1209 * @p: Task structure to be checked.
1211 * Test if a process is not yet dead (at most zombie state)
1212 * If pid_alive fails, then pointers within the task structure
1213 * can be stale and must not be dereferenced.
1215 * Return: 1 if the process is alive. 0 otherwise.
1217 static inline int pid_alive(const struct task_struct *p)
1219 return p->pids[PIDTYPE_PID].pid != NULL;
1222 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1224 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1227 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1229 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1233 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1235 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1238 static inline pid_t task_session_vnr(struct task_struct *tsk)
1240 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1243 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1245 return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns);
1248 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1250 return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL);
1253 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1259 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1265 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1267 return task_ppid_nr_ns(tsk, &init_pid_ns);
1270 /* Obsolete, do not use: */
1271 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1273 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1276 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1277 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1279 static inline unsigned int task_state_index(struct task_struct *tsk)
1281 unsigned int tsk_state = READ_ONCE(tsk->state);
1282 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1284 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1286 if (tsk_state == TASK_IDLE)
1287 state = TASK_REPORT_IDLE;
1292 static inline char task_index_to_char(unsigned int state)
1294 static const char state_char[] = "RSDTtXZPI";
1296 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1298 return state_char[state];
1301 static inline char task_state_to_char(struct task_struct *tsk)
1303 return task_index_to_char(task_state_index(tsk));
1307 * is_global_init - check if a task structure is init. Since init
1308 * is free to have sub-threads we need to check tgid.
1309 * @tsk: Task structure to be checked.
1311 * Check if a task structure is the first user space task the kernel created.
1313 * Return: 1 if the task structure is init. 0 otherwise.
1315 static inline int is_global_init(struct task_struct *tsk)
1317 return task_tgid_nr(tsk) == 1;
1320 extern struct pid *cad_pid;
1325 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1326 #define PF_EXITING 0x00000004 /* Getting shut down */
1327 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1328 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1329 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1330 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1331 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1332 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1333 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1334 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1335 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1336 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1337 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1338 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1339 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1340 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1341 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1342 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1343 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1344 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1345 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1346 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1347 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1348 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
1349 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1350 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1351 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1352 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1355 * Only the _current_ task can read/write to tsk->flags, but other
1356 * tasks can access tsk->flags in readonly mode for example
1357 * with tsk_used_math (like during threaded core dumping).
1358 * There is however an exception to this rule during ptrace
1359 * or during fork: the ptracer task is allowed to write to the
1360 * child->flags of its traced child (same goes for fork, the parent
1361 * can write to the child->flags), because we're guaranteed the
1362 * child is not running and in turn not changing child->flags
1363 * at the same time the parent does it.
1365 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1366 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1367 #define clear_used_math() clear_stopped_child_used_math(current)
1368 #define set_used_math() set_stopped_child_used_math(current)
1370 #define conditional_stopped_child_used_math(condition, child) \
1371 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1373 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1375 #define copy_to_stopped_child_used_math(child) \
1376 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1378 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1379 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1380 #define used_math() tsk_used_math(current)
1382 static inline bool is_percpu_thread(void)
1385 return (current->flags & PF_NO_SETAFFINITY) &&
1386 (current->nr_cpus_allowed == 1);
1392 /* Per-process atomic flags. */
1393 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1394 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1395 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1398 #define TASK_PFA_TEST(name, func) \
1399 static inline bool task_##func(struct task_struct *p) \
1400 { return test_bit(PFA_##name, &p->atomic_flags); }
1402 #define TASK_PFA_SET(name, func) \
1403 static inline void task_set_##func(struct task_struct *p) \
1404 { set_bit(PFA_##name, &p->atomic_flags); }
1406 #define TASK_PFA_CLEAR(name, func) \
1407 static inline void task_clear_##func(struct task_struct *p) \
1408 { clear_bit(PFA_##name, &p->atomic_flags); }
1410 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1411 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1413 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1414 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1415 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1417 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1418 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1419 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1422 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1424 current->flags &= ~flags;
1425 current->flags |= orig_flags & flags;
1428 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1429 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1431 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1432 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1434 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1437 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1439 if (!cpumask_test_cpu(0, new_mask))
1445 #ifndef cpu_relax_yield
1446 #define cpu_relax_yield() cpu_relax()
1449 extern int yield_to(struct task_struct *p, bool preempt);
1450 extern void set_user_nice(struct task_struct *p, long nice);
1451 extern int task_prio(const struct task_struct *p);
1454 * task_nice - return the nice value of a given task.
1455 * @p: the task in question.
1457 * Return: The nice value [ -20 ... 0 ... 19 ].
1459 static inline int task_nice(const struct task_struct *p)
1461 return PRIO_TO_NICE((p)->static_prio);
1464 extern int can_nice(const struct task_struct *p, const int nice);
1465 extern int task_curr(const struct task_struct *p);
1466 extern int idle_cpu(int cpu);
1467 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1468 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1469 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1470 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1471 extern struct task_struct *idle_task(int cpu);
1474 * is_idle_task - is the specified task an idle task?
1475 * @p: the task in question.
1477 * Return: 1 if @p is an idle task. 0 otherwise.
1479 static inline bool is_idle_task(const struct task_struct *p)
1481 return !!(p->flags & PF_IDLE);
1484 extern struct task_struct *curr_task(int cpu);
1485 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1489 union thread_union {
1490 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1491 struct task_struct task;
1493 #ifndef CONFIG_THREAD_INFO_IN_TASK
1494 struct thread_info thread_info;
1496 unsigned long stack[THREAD_SIZE/sizeof(long)];
1499 #ifndef CONFIG_THREAD_INFO_IN_TASK
1500 extern struct thread_info init_thread_info;
1503 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1505 #ifdef CONFIG_THREAD_INFO_IN_TASK
1506 static inline struct thread_info *task_thread_info(struct task_struct *task)
1508 return &task->thread_info;
1510 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1511 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1515 * find a task by one of its numerical ids
1517 * find_task_by_pid_ns():
1518 * finds a task by its pid in the specified namespace
1519 * find_task_by_vpid():
1520 * finds a task by its virtual pid
1522 * see also find_vpid() etc in include/linux/pid.h
1525 extern struct task_struct *find_task_by_vpid(pid_t nr);
1526 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1529 * find a task by its virtual pid and get the task struct
1531 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1533 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1534 extern int wake_up_process(struct task_struct *tsk);
1535 extern void wake_up_new_task(struct task_struct *tsk);
1538 extern void kick_process(struct task_struct *tsk);
1540 static inline void kick_process(struct task_struct *tsk) { }
1543 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1545 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1547 __set_task_comm(tsk, from, false);
1550 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1551 #define get_task_comm(buf, tsk) ({ \
1552 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1553 __get_task_comm(buf, sizeof(buf), tsk); \
1557 void scheduler_ipi(void);
1558 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1560 static inline void scheduler_ipi(void) { }
1561 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1568 * Set thread flags in other task's structures.
1569 * See asm/thread_info.h for TIF_xxxx flags available:
1571 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1573 set_ti_thread_flag(task_thread_info(tsk), flag);
1576 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1578 clear_ti_thread_flag(task_thread_info(tsk), flag);
1581 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1583 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1586 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1588 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1591 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1593 return test_ti_thread_flag(task_thread_info(tsk), flag);
1596 static inline void set_tsk_need_resched(struct task_struct *tsk)
1598 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1601 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1603 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1606 static inline int test_tsk_need_resched(struct task_struct *tsk)
1608 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1612 * cond_resched() and cond_resched_lock(): latency reduction via
1613 * explicit rescheduling in places that are safe. The return
1614 * value indicates whether a reschedule was done in fact.
1615 * cond_resched_lock() will drop the spinlock before scheduling,
1616 * cond_resched_softirq() will enable bhs before scheduling.
1618 #ifndef CONFIG_PREEMPT
1619 extern int _cond_resched(void);
1621 static inline int _cond_resched(void) { return 0; }
1624 #define cond_resched() ({ \
1625 ___might_sleep(__FILE__, __LINE__, 0); \
1629 extern int __cond_resched_lock(spinlock_t *lock);
1631 #define cond_resched_lock(lock) ({ \
1632 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1633 __cond_resched_lock(lock); \
1636 extern int __cond_resched_softirq(void);
1638 #define cond_resched_softirq() ({ \
1639 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
1640 __cond_resched_softirq(); \
1643 static inline void cond_resched_rcu(void)
1645 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1653 * Does a critical section need to be broken due to another
1654 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1655 * but a general need for low latency)
1657 static inline int spin_needbreak(spinlock_t *lock)
1659 #ifdef CONFIG_PREEMPT
1660 return spin_is_contended(lock);
1666 static __always_inline bool need_resched(void)
1668 return unlikely(tif_need_resched());
1672 * Wrappers for p->thread_info->cpu access. No-op on UP.
1676 static inline unsigned int task_cpu(const struct task_struct *p)
1678 #ifdef CONFIG_THREAD_INFO_IN_TASK
1681 return task_thread_info(p)->cpu;
1685 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1689 static inline unsigned int task_cpu(const struct task_struct *p)
1694 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1698 #endif /* CONFIG_SMP */
1701 * In order to reduce various lock holder preemption latencies provide an
1702 * interface to see if a vCPU is currently running or not.
1704 * This allows us to terminate optimistic spin loops and block, analogous to
1705 * the native optimistic spin heuristic of testing if the lock owner task is
1708 #ifndef vcpu_is_preempted
1709 # define vcpu_is_preempted(cpu) false
1712 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1713 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1715 #ifndef TASK_SIZE_OF
1716 #define TASK_SIZE_OF(tsk) TASK_SIZE