4 #include <uapi/linux/sched.h>
6 #include <linux/sched/prio.h>
13 #include <asm/param.h> /* for HZ */
15 #include <linux/capability.h>
16 #include <linux/threads.h>
17 #include <linux/kernel.h>
18 #include <linux/types.h>
19 #include <linux/timex.h>
20 #include <linux/jiffies.h>
21 #include <linux/plist.h>
22 #include <linux/rbtree.h>
23 #include <linux/thread_info.h>
24 #include <linux/cpumask.h>
25 #include <linux/errno.h>
26 #include <linux/nodemask.h>
27 #include <linux/mm_types.h>
28 #include <linux/preempt.h>
31 #include <asm/ptrace.h>
32 #include <linux/cputime.h>
34 #include <linux/smp.h>
35 #include <linux/sem.h>
36 #include <linux/shm.h>
37 #include <linux/signal.h>
38 #include <linux/compiler.h>
39 #include <linux/completion.h>
40 #include <linux/pid.h>
41 #include <linux/percpu.h>
42 #include <linux/topology.h>
43 #include <linux/proportions.h>
44 #include <linux/seccomp.h>
45 #include <linux/rcupdate.h>
46 #include <linux/rculist.h>
47 #include <linux/rtmutex.h>
49 #include <linux/time.h>
50 #include <linux/param.h>
51 #include <linux/resource.h>
52 #include <linux/timer.h>
53 #include <linux/hrtimer.h>
54 #include <linux/task_io_accounting.h>
55 #include <linux/latencytop.h>
56 #include <linux/cred.h>
57 #include <linux/llist.h>
58 #include <linux/uidgid.h>
59 #include <linux/gfp.h>
60 #include <linux/magic.h>
62 #include <asm/processor.h>
64 #define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */
67 * Extended scheduling parameters data structure.
69 * This is needed because the original struct sched_param can not be
70 * altered without introducing ABI issues with legacy applications
71 * (e.g., in sched_getparam()).
73 * However, the possibility of specifying more than just a priority for
74 * the tasks may be useful for a wide variety of application fields, e.g.,
75 * multimedia, streaming, automation and control, and many others.
77 * This variant (sched_attr) is meant at describing a so-called
78 * sporadic time-constrained task. In such model a task is specified by:
79 * - the activation period or minimum instance inter-arrival time;
80 * - the maximum (or average, depending on the actual scheduling
81 * discipline) computation time of all instances, a.k.a. runtime;
82 * - the deadline (relative to the actual activation time) of each
84 * Very briefly, a periodic (sporadic) task asks for the execution of
85 * some specific computation --which is typically called an instance--
86 * (at most) every period. Moreover, each instance typically lasts no more
87 * than the runtime and must be completed by time instant t equal to
88 * the instance activation time + the deadline.
90 * This is reflected by the actual fields of the sched_attr structure:
92 * @size size of the structure, for fwd/bwd compat.
94 * @sched_policy task's scheduling policy
95 * @sched_flags for customizing the scheduler behaviour
96 * @sched_nice task's nice value (SCHED_NORMAL/BATCH)
97 * @sched_priority task's static priority (SCHED_FIFO/RR)
98 * @sched_deadline representative of the task's deadline
99 * @sched_runtime representative of the task's runtime
100 * @sched_period representative of the task's period
102 * Given this task model, there are a multiplicity of scheduling algorithms
103 * and policies, that can be used to ensure all the tasks will make their
104 * timing constraints.
106 * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
107 * only user of this new interface. More information about the algorithm
108 * available in the scheduling class file or in Documentation/.
116 /* SCHED_NORMAL, SCHED_BATCH */
119 /* SCHED_FIFO, SCHED_RR */
128 struct futex_pi_state;
129 struct robust_list_head;
132 struct perf_event_context;
137 #define VMACACHE_BITS 2
138 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
139 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
142 * These are the constant used to fake the fixed-point load-average
143 * counting. Some notes:
144 * - 11 bit fractions expand to 22 bits by the multiplies: this gives
145 * a load-average precision of 10 bits integer + 11 bits fractional
146 * - if you want to count load-averages more often, you need more
147 * precision, or rounding will get you. With 2-second counting freq,
148 * the EXP_n values would be 1981, 2034 and 2043 if still using only
151 extern unsigned long avenrun[]; /* Load averages */
152 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
154 #define FSHIFT 11 /* nr of bits of precision */
155 #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
156 #define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
157 #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
158 #define EXP_5 2014 /* 1/exp(5sec/5min) */
159 #define EXP_15 2037 /* 1/exp(5sec/15min) */
161 #define CALC_LOAD(load,exp,n) \
163 load += n*(FIXED_1-exp); \
166 extern unsigned long total_forks;
167 extern int nr_threads;
168 DECLARE_PER_CPU(unsigned long, process_counts);
169 extern int nr_processes(void);
170 extern unsigned long nr_running(void);
171 extern bool single_task_running(void);
172 extern unsigned long nr_iowait(void);
173 extern unsigned long nr_iowait_cpu(int cpu);
174 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
176 extern void calc_global_load(unsigned long ticks);
178 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
179 extern void update_cpu_load_nohz(void);
181 static inline void update_cpu_load_nohz(void) { }
184 extern unsigned long get_parent_ip(unsigned long addr);
186 extern void dump_cpu_task(int cpu);
191 #ifdef CONFIG_SCHED_DEBUG
192 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
193 extern void proc_sched_set_task(struct task_struct *p);
195 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
199 * Task state bitmask. NOTE! These bits are also
200 * encoded in fs/proc/array.c: get_task_state().
202 * We have two separate sets of flags: task->state
203 * is about runnability, while task->exit_state are
204 * about the task exiting. Confusing, but this way
205 * modifying one set can't modify the other one by
208 #define TASK_RUNNING 0
209 #define TASK_INTERRUPTIBLE 1
210 #define TASK_UNINTERRUPTIBLE 2
211 #define __TASK_STOPPED 4
212 #define __TASK_TRACED 8
213 /* in tsk->exit_state */
215 #define EXIT_ZOMBIE 32
216 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
217 /* in tsk->state again */
219 #define TASK_WAKEKILL 128
220 #define TASK_WAKING 256
221 #define TASK_PARKED 512
222 #define TASK_NOLOAD 1024
223 #define TASK_STATE_MAX 2048
225 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN"
227 extern char ___assert_task_state[1 - 2*!!(
228 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
230 /* Convenience macros for the sake of set_task_state */
231 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
232 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
233 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
235 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
237 /* Convenience macros for the sake of wake_up */
238 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
239 #define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
241 /* get_task_state() */
242 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
243 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
244 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
246 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
247 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
248 #define task_is_stopped_or_traced(task) \
249 ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
250 #define task_contributes_to_load(task) \
251 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
252 (task->flags & PF_FROZEN) == 0 && \
253 (task->state & TASK_NOLOAD) == 0)
255 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
257 #define __set_task_state(tsk, state_value) \
259 (tsk)->task_state_change = _THIS_IP_; \
260 (tsk)->state = (state_value); \
262 #define set_task_state(tsk, state_value) \
264 (tsk)->task_state_change = _THIS_IP_; \
265 smp_store_mb((tsk)->state, (state_value)); \
269 * set_current_state() includes a barrier so that the write of current->state
270 * is correctly serialised wrt the caller's subsequent test of whether to
273 * set_current_state(TASK_UNINTERRUPTIBLE);
274 * if (do_i_need_to_sleep())
277 * If the caller does not need such serialisation then use __set_current_state()
279 #define __set_current_state(state_value) \
281 current->task_state_change = _THIS_IP_; \
282 current->state = (state_value); \
284 #define set_current_state(state_value) \
286 current->task_state_change = _THIS_IP_; \
287 smp_store_mb(current->state, (state_value)); \
292 #define __set_task_state(tsk, state_value) \
293 do { (tsk)->state = (state_value); } while (0)
294 #define set_task_state(tsk, state_value) \
295 smp_store_mb((tsk)->state, (state_value))
298 * set_current_state() includes a barrier so that the write of current->state
299 * is correctly serialised wrt the caller's subsequent test of whether to
302 * set_current_state(TASK_UNINTERRUPTIBLE);
303 * if (do_i_need_to_sleep())
306 * If the caller does not need such serialisation then use __set_current_state()
308 #define __set_current_state(state_value) \
309 do { current->state = (state_value); } while (0)
310 #define set_current_state(state_value) \
311 smp_store_mb(current->state, (state_value))
315 /* Task command name length */
316 #define TASK_COMM_LEN 16
318 #include <linux/spinlock.h>
321 * This serializes "schedule()" and also protects
322 * the run-queue from deletions/modifications (but
323 * _adding_ to the beginning of the run-queue has
326 extern rwlock_t tasklist_lock;
327 extern spinlock_t mmlist_lock;
331 #ifdef CONFIG_PROVE_RCU
332 extern int lockdep_tasklist_lock_is_held(void);
333 #endif /* #ifdef CONFIG_PROVE_RCU */
335 extern void sched_init(void);
336 extern void sched_init_smp(void);
337 extern asmlinkage void schedule_tail(struct task_struct *prev);
338 extern void init_idle(struct task_struct *idle, int cpu);
339 extern void init_idle_bootup_task(struct task_struct *idle);
341 extern cpumask_var_t cpu_isolated_map;
343 extern int runqueue_is_locked(int cpu);
345 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
346 extern void nohz_balance_enter_idle(int cpu);
347 extern void set_cpu_sd_state_idle(void);
348 extern int get_nohz_timer_target(void);
350 static inline void nohz_balance_enter_idle(int cpu) { }
351 static inline void set_cpu_sd_state_idle(void) { }
355 * Only dump TASK_* tasks. (0 for all tasks)
357 extern void show_state_filter(unsigned long state_filter);
359 static inline void show_state(void)
361 show_state_filter(0);
364 extern void show_regs(struct pt_regs *);
367 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
368 * task), SP is the stack pointer of the first frame that should be shown in the back
369 * trace (or NULL if the entire call-chain of the task should be shown).
371 extern void show_stack(struct task_struct *task, unsigned long *sp);
373 extern void cpu_init (void);
374 extern void trap_init(void);
375 extern void update_process_times(int user);
376 extern void scheduler_tick(void);
378 extern void sched_show_task(struct task_struct *p);
380 #ifdef CONFIG_LOCKUP_DETECTOR
381 extern void touch_softlockup_watchdog(void);
382 extern void touch_softlockup_watchdog_sync(void);
383 extern void touch_all_softlockup_watchdogs(void);
384 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
386 size_t *lenp, loff_t *ppos);
387 extern unsigned int softlockup_panic;
388 void lockup_detector_init(void);
390 static inline void touch_softlockup_watchdog(void)
393 static inline void touch_softlockup_watchdog_sync(void)
396 static inline void touch_all_softlockup_watchdogs(void)
399 static inline void lockup_detector_init(void)
404 #ifdef CONFIG_DETECT_HUNG_TASK
405 void reset_hung_task_detector(void);
407 static inline void reset_hung_task_detector(void)
412 /* Attach to any functions which should be ignored in wchan output. */
413 #define __sched __attribute__((__section__(".sched.text")))
415 /* Linker adds these: start and end of __sched functions */
416 extern char __sched_text_start[], __sched_text_end[];
418 /* Is this address in the __sched functions? */
419 extern int in_sched_functions(unsigned long addr);
421 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
422 extern signed long schedule_timeout(signed long timeout);
423 extern signed long schedule_timeout_interruptible(signed long timeout);
424 extern signed long schedule_timeout_killable(signed long timeout);
425 extern signed long schedule_timeout_uninterruptible(signed long timeout);
426 asmlinkage void schedule(void);
427 extern void schedule_preempt_disabled(void);
429 extern long io_schedule_timeout(long timeout);
431 static inline void io_schedule(void)
433 io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
437 struct user_namespace;
440 extern void arch_pick_mmap_layout(struct mm_struct *mm);
442 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
443 unsigned long, unsigned long);
445 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
446 unsigned long len, unsigned long pgoff,
447 unsigned long flags);
449 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
452 #define SUID_DUMP_DISABLE 0 /* No setuid dumping */
453 #define SUID_DUMP_USER 1 /* Dump as user of process */
454 #define SUID_DUMP_ROOT 2 /* Dump as root */
458 /* for SUID_DUMP_* above */
459 #define MMF_DUMPABLE_BITS 2
460 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
462 extern void set_dumpable(struct mm_struct *mm, int value);
464 * This returns the actual value of the suid_dumpable flag. For things
465 * that are using this for checking for privilege transitions, it must
466 * test against SUID_DUMP_USER rather than treating it as a boolean
469 static inline int __get_dumpable(unsigned long mm_flags)
471 return mm_flags & MMF_DUMPABLE_MASK;
474 static inline int get_dumpable(struct mm_struct *mm)
476 return __get_dumpable(mm->flags);
479 /* coredump filter bits */
480 #define MMF_DUMP_ANON_PRIVATE 2
481 #define MMF_DUMP_ANON_SHARED 3
482 #define MMF_DUMP_MAPPED_PRIVATE 4
483 #define MMF_DUMP_MAPPED_SHARED 5
484 #define MMF_DUMP_ELF_HEADERS 6
485 #define MMF_DUMP_HUGETLB_PRIVATE 7
486 #define MMF_DUMP_HUGETLB_SHARED 8
488 #define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS
489 #define MMF_DUMP_FILTER_BITS 7
490 #define MMF_DUMP_FILTER_MASK \
491 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
492 #define MMF_DUMP_FILTER_DEFAULT \
493 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
494 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
496 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
497 # define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS)
499 # define MMF_DUMP_MASK_DEFAULT_ELF 0
501 /* leave room for more dump flags */
502 #define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */
503 #define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
504 #define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
506 #define MMF_HAS_UPROBES 19 /* has uprobes */
507 #define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
509 #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
511 struct sighand_struct {
513 struct k_sigaction action[_NSIG];
515 wait_queue_head_t signalfd_wqh;
518 struct pacct_struct {
521 unsigned long ac_mem;
522 cputime_t ac_utime, ac_stime;
523 unsigned long ac_minflt, ac_majflt;
534 * struct cputime - snaphsot of system and user cputime
535 * @utime: time spent in user mode
536 * @stime: time spent in system mode
538 * Gathers a generic snapshot of user and system time.
546 * struct task_cputime - collected CPU time counts
547 * @utime: time spent in user mode, in &cputime_t units
548 * @stime: time spent in kernel mode, in &cputime_t units
549 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
551 * This is an extension of struct cputime that includes the total runtime
552 * spent by the task from the scheduler point of view.
554 * As a result, this structure groups together three kinds of CPU time
555 * that are tracked for threads and thread groups. Most things considering
556 * CPU time want to group these counts together and treat all three
557 * of them in parallel.
559 struct task_cputime {
562 unsigned long long sum_exec_runtime;
564 /* Alternate field names when used to cache expirations. */
565 #define prof_exp stime
566 #define virt_exp utime
567 #define sched_exp sum_exec_runtime
569 #define INIT_CPUTIME \
570 (struct task_cputime) { \
573 .sum_exec_runtime = 0, \
577 * This is the atomic variant of task_cputime, which can be used for
578 * storing and updating task_cputime statistics without locking.
580 struct task_cputime_atomic {
583 atomic64_t sum_exec_runtime;
586 #define INIT_CPUTIME_ATOMIC \
587 (struct task_cputime_atomic) { \
588 .utime = ATOMIC64_INIT(0), \
589 .stime = ATOMIC64_INIT(0), \
590 .sum_exec_runtime = ATOMIC64_INIT(0), \
593 #ifdef CONFIG_PREEMPT_COUNT
594 #define PREEMPT_DISABLED (1 + PREEMPT_ENABLED)
596 #define PREEMPT_DISABLED PREEMPT_ENABLED
600 * Disable preemption until the scheduler is running.
601 * Reset by start_kernel()->sched_init()->init_idle().
603 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
604 * before the scheduler is active -- see should_resched().
606 #define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE)
609 * struct thread_group_cputimer - thread group interval timer counts
610 * @cputime_atomic: atomic thread group interval timers.
611 * @running: non-zero when there are timers running and
612 * @cputime receives updates.
614 * This structure contains the version of task_cputime, above, that is
615 * used for thread group CPU timer calculations.
617 struct thread_group_cputimer {
618 struct task_cputime_atomic cputime_atomic;
622 #include <linux/rwsem.h>
626 * NOTE! "signal_struct" does not have its own
627 * locking, because a shared signal_struct always
628 * implies a shared sighand_struct, so locking
629 * sighand_struct is always a proper superset of
630 * the locking of signal_struct.
632 struct signal_struct {
636 struct list_head thread_head;
638 wait_queue_head_t wait_chldexit; /* for wait4() */
640 /* current thread group signal load-balancing target: */
641 struct task_struct *curr_target;
643 /* shared signal handling: */
644 struct sigpending shared_pending;
646 /* thread group exit support */
649 * - notify group_exit_task when ->count is equal to notify_count
650 * - everyone except group_exit_task is stopped during signal delivery
651 * of fatal signals, group_exit_task processes the signal.
654 struct task_struct *group_exit_task;
656 /* thread group stop support, overloads group_exit_code too */
657 int group_stop_count;
658 unsigned int flags; /* see SIGNAL_* flags below */
661 * PR_SET_CHILD_SUBREAPER marks a process, like a service
662 * manager, to re-parent orphan (double-forking) child processes
663 * to this process instead of 'init'. The service manager is
664 * able to receive SIGCHLD signals and is able to investigate
665 * the process until it calls wait(). All children of this
666 * process will inherit a flag if they should look for a
667 * child_subreaper process at exit.
669 unsigned int is_child_subreaper:1;
670 unsigned int has_child_subreaper:1;
672 /* POSIX.1b Interval Timers */
674 struct list_head posix_timers;
676 /* ITIMER_REAL timer for the process */
677 struct hrtimer real_timer;
678 struct pid *leader_pid;
679 ktime_t it_real_incr;
682 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
683 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
684 * values are defined to 0 and 1 respectively
686 struct cpu_itimer it[2];
689 * Thread group totals for process CPU timers.
690 * See thread_group_cputimer(), et al, for details.
692 struct thread_group_cputimer cputimer;
694 /* Earliest-expiration cache. */
695 struct task_cputime cputime_expires;
697 struct list_head cpu_timers[3];
699 struct pid *tty_old_pgrp;
701 /* boolean value for session group leader */
704 struct tty_struct *tty; /* NULL if no tty */
706 #ifdef CONFIG_SCHED_AUTOGROUP
707 struct autogroup *autogroup;
710 * Cumulative resource counters for dead threads in the group,
711 * and for reaped dead child processes forked by this group.
712 * Live threads maintain their own counters and add to these
713 * in __exit_signal, except for the group leader.
715 seqlock_t stats_lock;
716 cputime_t utime, stime, cutime, cstime;
719 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
720 struct cputime prev_cputime;
722 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
723 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
724 unsigned long inblock, oublock, cinblock, coublock;
725 unsigned long maxrss, cmaxrss;
726 struct task_io_accounting ioac;
729 * Cumulative ns of schedule CPU time fo dead threads in the
730 * group, not including a zombie group leader, (This only differs
731 * from jiffies_to_ns(utime + stime) if sched_clock uses something
732 * other than jiffies.)
734 unsigned long long sum_sched_runtime;
737 * We don't bother to synchronize most readers of this at all,
738 * because there is no reader checking a limit that actually needs
739 * to get both rlim_cur and rlim_max atomically, and either one
740 * alone is a single word that can safely be read normally.
741 * getrlimit/setrlimit use task_lock(current->group_leader) to
742 * protect this instead of the siglock, because they really
743 * have no need to disable irqs.
745 struct rlimit rlim[RLIM_NLIMITS];
747 #ifdef CONFIG_BSD_PROCESS_ACCT
748 struct pacct_struct pacct; /* per-process accounting information */
750 #ifdef CONFIG_TASKSTATS
751 struct taskstats *stats;
755 unsigned audit_tty_log_passwd;
756 struct tty_audit_buf *tty_audit_buf;
758 #ifdef CONFIG_CGROUPS
760 * group_rwsem prevents new tasks from entering the threadgroup and
761 * member tasks from exiting,a more specifically, setting of
762 * PF_EXITING. fork and exit paths are protected with this rwsem
763 * using threadgroup_change_begin/end(). Users which require
764 * threadgroup to remain stable should use threadgroup_[un]lock()
765 * which also takes care of exec path. Currently, cgroup is the
768 struct rw_semaphore group_rwsem;
771 oom_flags_t oom_flags;
772 short oom_score_adj; /* OOM kill score adjustment */
773 short oom_score_adj_min; /* OOM kill score adjustment min value.
774 * Only settable by CAP_SYS_RESOURCE. */
776 struct mutex cred_guard_mutex; /* guard against foreign influences on
777 * credential calculations
778 * (notably. ptrace) */
782 * Bits in flags field of signal_struct.
784 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
785 #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
786 #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
787 #define SIGNAL_GROUP_COREDUMP 0x00000008 /* coredump in progress */
789 * Pending notifications to parent.
791 #define SIGNAL_CLD_STOPPED 0x00000010
792 #define SIGNAL_CLD_CONTINUED 0x00000020
793 #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
795 #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
797 /* If true, all threads except ->group_exit_task have pending SIGKILL */
798 static inline int signal_group_exit(const struct signal_struct *sig)
800 return (sig->flags & SIGNAL_GROUP_EXIT) ||
801 (sig->group_exit_task != NULL);
805 * Some day this will be a full-fledged user tracking system..
808 atomic_t __count; /* reference count */
809 atomic_t processes; /* How many processes does this user have? */
810 atomic_t sigpending; /* How many pending signals does this user have? */
811 #ifdef CONFIG_INOTIFY_USER
812 atomic_t inotify_watches; /* How many inotify watches does this user have? */
813 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
815 #ifdef CONFIG_FANOTIFY
816 atomic_t fanotify_listeners;
819 atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
821 #ifdef CONFIG_POSIX_MQUEUE
822 /* protected by mq_lock */
823 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
825 unsigned long locked_shm; /* How many pages of mlocked shm ? */
828 struct key *uid_keyring; /* UID specific keyring */
829 struct key *session_keyring; /* UID's default session keyring */
832 /* Hash table maintenance information */
833 struct hlist_node uidhash_node;
836 #ifdef CONFIG_PERF_EVENTS
837 atomic_long_t locked_vm;
841 extern int uids_sysfs_init(void);
843 extern struct user_struct *find_user(kuid_t);
845 extern struct user_struct root_user;
846 #define INIT_USER (&root_user)
849 struct backing_dev_info;
850 struct reclaim_state;
852 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
854 /* cumulative counters */
855 unsigned long pcount; /* # of times run on this cpu */
856 unsigned long long run_delay; /* time spent waiting on a runqueue */
859 unsigned long long last_arrival,/* when we last ran on a cpu */
860 last_queued; /* when we were last queued to run */
862 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
864 #ifdef CONFIG_TASK_DELAY_ACCT
865 struct task_delay_info {
867 unsigned int flags; /* Private per-task flags */
869 /* For each stat XXX, add following, aligned appropriately
871 * struct timespec XXX_start, XXX_end;
875 * Atomicity of updates to XXX_delay, XXX_count protected by
876 * single lock above (split into XXX_lock if contention is an issue).
880 * XXX_count is incremented on every XXX operation, the delay
881 * associated with the operation is added to XXX_delay.
882 * XXX_delay contains the accumulated delay time in nanoseconds.
884 u64 blkio_start; /* Shared by blkio, swapin */
885 u64 blkio_delay; /* wait for sync block io completion */
886 u64 swapin_delay; /* wait for swapin block io completion */
887 u32 blkio_count; /* total count of the number of sync block */
888 /* io operations performed */
889 u32 swapin_count; /* total count of the number of swapin block */
890 /* io operations performed */
893 u64 freepages_delay; /* wait for memory reclaim */
894 u32 freepages_count; /* total count of memory reclaim */
896 #endif /* CONFIG_TASK_DELAY_ACCT */
898 static inline int sched_info_on(void)
900 #ifdef CONFIG_SCHEDSTATS
902 #elif defined(CONFIG_TASK_DELAY_ACCT)
903 extern int delayacct_on;
918 * Increase resolution of cpu_capacity calculations
920 #define SCHED_CAPACITY_SHIFT 10
921 #define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
924 * Wake-queues are lists of tasks with a pending wakeup, whose
925 * callers have already marked the task as woken internally,
926 * and can thus carry on. A common use case is being able to
927 * do the wakeups once the corresponding user lock as been
930 * We hold reference to each task in the list across the wakeup,
931 * thus guaranteeing that the memory is still valid by the time
932 * the actual wakeups are performed in wake_up_q().
934 * One per task suffices, because there's never a need for a task to be
935 * in two wake queues simultaneously; it is forbidden to abandon a task
936 * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
937 * already in a wake queue, the wakeup will happen soon and the second
938 * waker can just skip it.
940 * The WAKE_Q macro declares and initializes the list head.
941 * wake_up_q() does NOT reinitialize the list; it's expected to be
942 * called near the end of a function, where the fact that the queue is
943 * not used again will be easy to see by inspection.
945 * Note that this can cause spurious wakeups. schedule() callers
946 * must ensure the call is done inside a loop, confirming that the
947 * wakeup condition has in fact occurred.
950 struct wake_q_node *next;
954 struct wake_q_node *first;
955 struct wake_q_node **lastp;
958 #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
960 #define WAKE_Q(name) \
961 struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
963 extern void wake_q_add(struct wake_q_head *head,
964 struct task_struct *task);
965 extern void wake_up_q(struct wake_q_head *head);
968 * sched-domains (multiprocessor balancing) declarations:
971 #define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */
972 #define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
973 #define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
974 #define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
975 #define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
976 #define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
977 #define SD_SHARE_CPUCAPACITY 0x0080 /* Domain members share cpu power */
978 #define SD_SHARE_POWERDOMAIN 0x0100 /* Domain members share power domain */
979 #define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
980 #define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
981 #define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */
982 #define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
983 #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */
984 #define SD_NUMA 0x4000 /* cross-node balancing */
986 #ifdef CONFIG_SCHED_SMT
987 static inline int cpu_smt_flags(void)
989 return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
993 #ifdef CONFIG_SCHED_MC
994 static inline int cpu_core_flags(void)
996 return SD_SHARE_PKG_RESOURCES;
1001 static inline int cpu_numa_flags(void)
1007 struct sched_domain_attr {
1008 int relax_domain_level;
1011 #define SD_ATTR_INIT (struct sched_domain_attr) { \
1012 .relax_domain_level = -1, \
1015 extern int sched_domain_level_max;
1019 struct sched_domain {
1020 /* These fields must be setup */
1021 struct sched_domain *parent; /* top domain must be null terminated */
1022 struct sched_domain *child; /* bottom domain must be null terminated */
1023 struct sched_group *groups; /* the balancing groups of the domain */
1024 unsigned long min_interval; /* Minimum balance interval ms */
1025 unsigned long max_interval; /* Maximum balance interval ms */
1026 unsigned int busy_factor; /* less balancing by factor if busy */
1027 unsigned int imbalance_pct; /* No balance until over watermark */
1028 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
1029 unsigned int busy_idx;
1030 unsigned int idle_idx;
1031 unsigned int newidle_idx;
1032 unsigned int wake_idx;
1033 unsigned int forkexec_idx;
1034 unsigned int smt_gain;
1036 int nohz_idle; /* NOHZ IDLE status */
1037 int flags; /* See SD_* */
1040 /* Runtime fields. */
1041 unsigned long last_balance; /* init to jiffies. units in jiffies */
1042 unsigned int balance_interval; /* initialise to 1. units in ms. */
1043 unsigned int nr_balance_failed; /* initialise to 0 */
1045 /* idle_balance() stats */
1046 u64 max_newidle_lb_cost;
1047 unsigned long next_decay_max_lb_cost;
1049 #ifdef CONFIG_SCHEDSTATS
1050 /* load_balance() stats */
1051 unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1052 unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1053 unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1054 unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1055 unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1056 unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1057 unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1058 unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1060 /* Active load balancing */
1061 unsigned int alb_count;
1062 unsigned int alb_failed;
1063 unsigned int alb_pushed;
1065 /* SD_BALANCE_EXEC stats */
1066 unsigned int sbe_count;
1067 unsigned int sbe_balanced;
1068 unsigned int sbe_pushed;
1070 /* SD_BALANCE_FORK stats */
1071 unsigned int sbf_count;
1072 unsigned int sbf_balanced;
1073 unsigned int sbf_pushed;
1075 /* try_to_wake_up() stats */
1076 unsigned int ttwu_wake_remote;
1077 unsigned int ttwu_move_affine;
1078 unsigned int ttwu_move_balance;
1080 #ifdef CONFIG_SCHED_DEBUG
1084 void *private; /* used during construction */
1085 struct rcu_head rcu; /* used during destruction */
1088 unsigned int span_weight;
1090 * Span of all CPUs in this domain.
1092 * NOTE: this field is variable length. (Allocated dynamically
1093 * by attaching extra space to the end of the structure,
1094 * depending on how many CPUs the kernel has booted up with)
1096 unsigned long span[0];
1099 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1101 return to_cpumask(sd->span);
1104 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1105 struct sched_domain_attr *dattr_new);
1107 /* Allocate an array of sched domains, for partition_sched_domains(). */
1108 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1109 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1111 bool cpus_share_cache(int this_cpu, int that_cpu);
1113 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1114 typedef int (*sched_domain_flags_f)(void);
1116 #define SDTL_OVERLAP 0x01
1119 struct sched_domain **__percpu sd;
1120 struct sched_group **__percpu sg;
1121 struct sched_group_capacity **__percpu sgc;
1124 struct sched_domain_topology_level {
1125 sched_domain_mask_f mask;
1126 sched_domain_flags_f sd_flags;
1129 struct sd_data data;
1130 #ifdef CONFIG_SCHED_DEBUG
1135 extern struct sched_domain_topology_level *sched_domain_topology;
1137 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1138 extern void wake_up_if_idle(int cpu);
1140 #ifdef CONFIG_SCHED_DEBUG
1141 # define SD_INIT_NAME(type) .name = #type
1143 # define SD_INIT_NAME(type)
1146 #else /* CONFIG_SMP */
1148 struct sched_domain_attr;
1151 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1152 struct sched_domain_attr *dattr_new)
1156 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1161 #endif /* !CONFIG_SMP */
1164 struct io_context; /* See blkdev.h */
1167 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1168 extern void prefetch_stack(struct task_struct *t);
1170 static inline void prefetch_stack(struct task_struct *t) { }
1173 struct audit_context; /* See audit.c */
1175 struct pipe_inode_info;
1176 struct uts_namespace;
1178 struct load_weight {
1179 unsigned long weight;
1184 u64 last_runnable_update;
1187 * utilization_avg_contrib describes the amount of time that a
1188 * sched_entity is running on a CPU. It is based on running_avg_sum
1189 * and is scaled in the range [0..SCHED_LOAD_SCALE].
1190 * load_avg_contrib described the amount of time that a sched_entity
1191 * is runnable on a rq. It is based on both runnable_avg_sum and the
1192 * weight of the task.
1194 unsigned long load_avg_contrib, utilization_avg_contrib;
1196 * These sums represent an infinite geometric series and so are bound
1197 * above by 1024/(1-y). Thus we only need a u32 to store them for all
1198 * choices of y < 1-2^(-32)*1024.
1199 * running_avg_sum reflects the time that the sched_entity is
1200 * effectively running on the CPU.
1201 * runnable_avg_sum represents the amount of time a sched_entity is on
1202 * a runqueue which includes the running time that is monitored by
1205 u32 runnable_avg_sum, avg_period, running_avg_sum;
1208 #ifdef CONFIG_SCHEDSTATS
1209 struct sched_statistics {
1219 s64 sum_sleep_runtime;
1226 u64 nr_migrations_cold;
1227 u64 nr_failed_migrations_affine;
1228 u64 nr_failed_migrations_running;
1229 u64 nr_failed_migrations_hot;
1230 u64 nr_forced_migrations;
1233 u64 nr_wakeups_sync;
1234 u64 nr_wakeups_migrate;
1235 u64 nr_wakeups_local;
1236 u64 nr_wakeups_remote;
1237 u64 nr_wakeups_affine;
1238 u64 nr_wakeups_affine_attempts;
1239 u64 nr_wakeups_passive;
1240 u64 nr_wakeups_idle;
1244 struct sched_entity {
1245 struct load_weight load; /* for load-balancing */
1246 struct rb_node run_node;
1247 struct list_head group_node;
1251 u64 sum_exec_runtime;
1253 u64 prev_sum_exec_runtime;
1257 #ifdef CONFIG_SCHEDSTATS
1258 struct sched_statistics statistics;
1261 #ifdef CONFIG_FAIR_GROUP_SCHED
1263 struct sched_entity *parent;
1264 /* rq on which this entity is (to be) queued: */
1265 struct cfs_rq *cfs_rq;
1266 /* rq "owned" by this entity/group: */
1267 struct cfs_rq *my_q;
1271 /* Per-entity load-tracking */
1272 struct sched_avg avg;
1276 struct sched_rt_entity {
1277 struct list_head run_list;
1278 unsigned long timeout;
1279 unsigned long watchdog_stamp;
1280 unsigned int time_slice;
1282 struct sched_rt_entity *back;
1283 #ifdef CONFIG_RT_GROUP_SCHED
1284 struct sched_rt_entity *parent;
1285 /* rq on which this entity is (to be) queued: */
1286 struct rt_rq *rt_rq;
1287 /* rq "owned" by this entity/group: */
1292 struct sched_dl_entity {
1293 struct rb_node rb_node;
1296 * Original scheduling parameters. Copied here from sched_attr
1297 * during sched_setattr(), they will remain the same until
1298 * the next sched_setattr().
1300 u64 dl_runtime; /* maximum runtime for each instance */
1301 u64 dl_deadline; /* relative deadline of each instance */
1302 u64 dl_period; /* separation of two instances (period) */
1303 u64 dl_bw; /* dl_runtime / dl_deadline */
1306 * Actual scheduling parameters. Initialized with the values above,
1307 * they are continously updated during task execution. Note that
1308 * the remaining runtime could be < 0 in case we are in overrun.
1310 s64 runtime; /* remaining runtime for this instance */
1311 u64 deadline; /* absolute deadline for this instance */
1312 unsigned int flags; /* specifying the scheduler behaviour */
1317 * @dl_throttled tells if we exhausted the runtime. If so, the
1318 * task has to wait for a replenishment to be performed at the
1319 * next firing of dl_timer.
1321 * @dl_new tells if a new instance arrived. If so we must
1322 * start executing it with full runtime and reset its absolute
1325 * @dl_boosted tells if we are boosted due to DI. If so we are
1326 * outside bandwidth enforcement mechanism (but only until we
1327 * exit the critical section);
1329 * @dl_yielded tells if task gave up the cpu before consuming
1330 * all its available runtime during the last job.
1332 int dl_throttled, dl_new, dl_boosted, dl_yielded;
1335 * Bandwidth enforcement timer. Each -deadline task has its
1336 * own bandwidth to be enforced, thus we need one timer per task.
1338 struct hrtimer dl_timer;
1350 enum perf_event_task_context {
1351 perf_invalid_context = -1,
1352 perf_hw_context = 0,
1354 perf_nr_task_contexts,
1357 struct task_struct {
1358 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
1361 unsigned int flags; /* per process flags, defined below */
1362 unsigned int ptrace;
1365 struct llist_node wake_entry;
1367 struct task_struct *last_wakee;
1368 unsigned long wakee_flips;
1369 unsigned long wakee_flip_decay_ts;
1375 int prio, static_prio, normal_prio;
1376 unsigned int rt_priority;
1377 const struct sched_class *sched_class;
1378 struct sched_entity se;
1379 struct sched_rt_entity rt;
1380 #ifdef CONFIG_CGROUP_SCHED
1381 struct task_group *sched_task_group;
1383 struct sched_dl_entity dl;
1385 #ifdef CONFIG_PREEMPT_NOTIFIERS
1386 /* list of struct preempt_notifier: */
1387 struct hlist_head preempt_notifiers;
1390 #ifdef CONFIG_BLK_DEV_IO_TRACE
1391 unsigned int btrace_seq;
1394 unsigned int policy;
1395 int nr_cpus_allowed;
1396 cpumask_t cpus_allowed;
1398 #ifdef CONFIG_PREEMPT_RCU
1399 int rcu_read_lock_nesting;
1400 union rcu_special rcu_read_unlock_special;
1401 struct list_head rcu_node_entry;
1402 struct rcu_node *rcu_blocked_node;
1403 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1404 #ifdef CONFIG_TASKS_RCU
1405 unsigned long rcu_tasks_nvcsw;
1406 bool rcu_tasks_holdout;
1407 struct list_head rcu_tasks_holdout_list;
1408 int rcu_tasks_idle_cpu;
1409 #endif /* #ifdef CONFIG_TASKS_RCU */
1411 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1412 struct sched_info sched_info;
1415 struct list_head tasks;
1417 struct plist_node pushable_tasks;
1418 struct rb_node pushable_dl_tasks;
1421 struct mm_struct *mm, *active_mm;
1422 /* per-thread vma caching */
1423 u32 vmacache_seqnum;
1424 struct vm_area_struct *vmacache[VMACACHE_SIZE];
1425 #if defined(SPLIT_RSS_COUNTING)
1426 struct task_rss_stat rss_stat;
1430 int exit_code, exit_signal;
1431 int pdeath_signal; /* The signal sent when the parent dies */
1432 unsigned long jobctl; /* JOBCTL_*, siglock protected */
1434 /* Used for emulating ABI behavior of previous Linux versions */
1435 unsigned int personality;
1437 unsigned in_execve:1; /* Tell the LSMs that the process is doing an
1439 unsigned in_iowait:1;
1441 /* Revert to default priority/policy when forking */
1442 unsigned sched_reset_on_fork:1;
1443 unsigned sched_contributes_to_load:1;
1444 unsigned sched_migrated:1;
1446 #ifdef CONFIG_MEMCG_KMEM
1447 unsigned memcg_kmem_skip_account:1;
1449 #ifdef CONFIG_COMPAT_BRK
1450 unsigned brk_randomized:1;
1453 unsigned long atomic_flags; /* Flags needing atomic access. */
1455 struct restart_block restart_block;
1460 #ifdef CONFIG_CC_STACKPROTECTOR
1461 /* Canary value for the -fstack-protector gcc feature */
1462 unsigned long stack_canary;
1465 * pointers to (original) parent process, youngest child, younger sibling,
1466 * older sibling, respectively. (p->father can be replaced with
1467 * p->real_parent->pid)
1469 struct task_struct __rcu *real_parent; /* real parent process */
1470 struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1472 * children/sibling forms the list of my natural children
1474 struct list_head children; /* list of my children */
1475 struct list_head sibling; /* linkage in my parent's children list */
1476 struct task_struct *group_leader; /* threadgroup leader */
1479 * ptraced is the list of tasks this task is using ptrace on.
1480 * This includes both natural children and PTRACE_ATTACH targets.
1481 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1483 struct list_head ptraced;
1484 struct list_head ptrace_entry;
1486 /* PID/PID hash table linkage. */
1487 struct pid_link pids[PIDTYPE_MAX];
1488 struct list_head thread_group;
1489 struct list_head thread_node;
1491 struct completion *vfork_done; /* for vfork() */
1492 int __user *set_child_tid; /* CLONE_CHILD_SETTID */
1493 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
1495 cputime_t utime, stime, utimescaled, stimescaled;
1497 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1498 struct cputime prev_cputime;
1500 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1501 seqlock_t vtime_seqlock;
1502 unsigned long long vtime_snap;
1507 } vtime_snap_whence;
1509 unsigned long nvcsw, nivcsw; /* context switch counts */
1510 u64 start_time; /* monotonic time in nsec */
1511 u64 real_start_time; /* boot based time in nsec */
1512 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1513 unsigned long min_flt, maj_flt;
1515 struct task_cputime cputime_expires;
1516 struct list_head cpu_timers[3];
1518 /* process credentials */
1519 const struct cred __rcu *real_cred; /* objective and real subjective task
1520 * credentials (COW) */
1521 const struct cred __rcu *cred; /* effective (overridable) subjective task
1522 * credentials (COW) */
1523 char comm[TASK_COMM_LEN]; /* executable name excluding path
1524 - access with [gs]et_task_comm (which lock
1525 it with task_lock())
1526 - initialized normally by setup_new_exec */
1527 /* file system info */
1528 struct nameidata *nameidata;
1529 #ifdef CONFIG_SYSVIPC
1531 struct sysv_sem sysvsem;
1532 struct sysv_shm sysvshm;
1534 #ifdef CONFIG_DETECT_HUNG_TASK
1535 /* hung task detection */
1536 unsigned long last_switch_count;
1538 /* CPU-specific state of this task */
1539 struct thread_struct thread;
1540 /* filesystem information */
1541 struct fs_struct *fs;
1542 /* open file information */
1543 struct files_struct *files;
1545 struct nsproxy *nsproxy;
1546 /* signal handlers */
1547 struct signal_struct *signal;
1548 struct sighand_struct *sighand;
1550 sigset_t blocked, real_blocked;
1551 sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1552 struct sigpending pending;
1554 unsigned long sas_ss_sp;
1556 int (*notifier)(void *priv);
1557 void *notifier_data;
1558 sigset_t *notifier_mask;
1559 struct callback_head *task_works;
1561 struct audit_context *audit_context;
1562 #ifdef CONFIG_AUDITSYSCALL
1564 unsigned int sessionid;
1566 struct seccomp seccomp;
1568 /* Thread group tracking */
1571 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1573 spinlock_t alloc_lock;
1575 /* Protection of the PI data structures: */
1576 raw_spinlock_t pi_lock;
1578 struct wake_q_node wake_q;
1580 #ifdef CONFIG_RT_MUTEXES
1581 /* PI waiters blocked on a rt_mutex held by this task */
1582 struct rb_root pi_waiters;
1583 struct rb_node *pi_waiters_leftmost;
1584 /* Deadlock detection and priority inheritance handling */
1585 struct rt_mutex_waiter *pi_blocked_on;
1588 #ifdef CONFIG_DEBUG_MUTEXES
1589 /* mutex deadlock detection */
1590 struct mutex_waiter *blocked_on;
1592 #ifdef CONFIG_TRACE_IRQFLAGS
1593 unsigned int irq_events;
1594 unsigned long hardirq_enable_ip;
1595 unsigned long hardirq_disable_ip;
1596 unsigned int hardirq_enable_event;
1597 unsigned int hardirq_disable_event;
1598 int hardirqs_enabled;
1599 int hardirq_context;
1600 unsigned long softirq_disable_ip;
1601 unsigned long softirq_enable_ip;
1602 unsigned int softirq_disable_event;
1603 unsigned int softirq_enable_event;
1604 int softirqs_enabled;
1605 int softirq_context;
1607 #ifdef CONFIG_LOCKDEP
1608 # define MAX_LOCK_DEPTH 48UL
1611 unsigned int lockdep_recursion;
1612 struct held_lock held_locks[MAX_LOCK_DEPTH];
1613 gfp_t lockdep_reclaim_gfp;
1616 /* journalling filesystem info */
1619 /* stacked block device info */
1620 struct bio_list *bio_list;
1623 /* stack plugging */
1624 struct blk_plug *plug;
1628 struct reclaim_state *reclaim_state;
1630 struct backing_dev_info *backing_dev_info;
1632 struct io_context *io_context;
1634 unsigned long ptrace_message;
1635 siginfo_t *last_siginfo; /* For ptrace use. */
1636 struct task_io_accounting ioac;
1637 #if defined(CONFIG_TASK_XACCT)
1638 u64 acct_rss_mem1; /* accumulated rss usage */
1639 u64 acct_vm_mem1; /* accumulated virtual memory usage */
1640 cputime_t acct_timexpd; /* stime + utime since last update */
1642 #ifdef CONFIG_CPUSETS
1643 nodemask_t mems_allowed; /* Protected by alloc_lock */
1644 seqcount_t mems_allowed_seq; /* Seqence no to catch updates */
1645 int cpuset_mem_spread_rotor;
1646 int cpuset_slab_spread_rotor;
1648 #ifdef CONFIG_CGROUPS
1649 /* Control Group info protected by css_set_lock */
1650 struct css_set __rcu *cgroups;
1651 /* cg_list protected by css_set_lock and tsk->alloc_lock */
1652 struct list_head cg_list;
1655 struct robust_list_head __user *robust_list;
1656 #ifdef CONFIG_COMPAT
1657 struct compat_robust_list_head __user *compat_robust_list;
1659 struct list_head pi_state_list;
1660 struct futex_pi_state *pi_state_cache;
1662 #ifdef CONFIG_PERF_EVENTS
1663 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1664 struct mutex perf_event_mutex;
1665 struct list_head perf_event_list;
1667 #ifdef CONFIG_DEBUG_PREEMPT
1668 unsigned long preempt_disable_ip;
1671 struct mempolicy *mempolicy; /* Protected by alloc_lock */
1673 short pref_node_fork;
1675 #ifdef CONFIG_NUMA_BALANCING
1677 unsigned int numa_scan_period;
1678 unsigned int numa_scan_period_max;
1679 int numa_preferred_nid;
1680 unsigned long numa_migrate_retry;
1681 u64 node_stamp; /* migration stamp */
1682 u64 last_task_numa_placement;
1683 u64 last_sum_exec_runtime;
1684 struct callback_head numa_work;
1686 struct list_head numa_entry;
1687 struct numa_group *numa_group;
1690 * numa_faults is an array split into four regions:
1691 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1692 * in this precise order.
1694 * faults_memory: Exponential decaying average of faults on a per-node
1695 * basis. Scheduling placement decisions are made based on these
1696 * counts. The values remain static for the duration of a PTE scan.
1697 * faults_cpu: Track the nodes the process was running on when a NUMA
1698 * hinting fault was incurred.
1699 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1700 * during the current scan window. When the scan completes, the counts
1701 * in faults_memory and faults_cpu decay and these values are copied.
1703 unsigned long *numa_faults;
1704 unsigned long total_numa_faults;
1707 * numa_faults_locality tracks if faults recorded during the last
1708 * scan window were remote/local or failed to migrate. The task scan
1709 * period is adapted based on the locality of the faults with different
1710 * weights depending on whether they were shared or private faults
1712 unsigned long numa_faults_locality[3];
1714 unsigned long numa_pages_migrated;
1715 #endif /* CONFIG_NUMA_BALANCING */
1717 struct rcu_head rcu;
1720 * cache last used pipe for splice
1722 struct pipe_inode_info *splice_pipe;
1724 struct page_frag task_frag;
1726 #ifdef CONFIG_TASK_DELAY_ACCT
1727 struct task_delay_info *delays;
1729 #ifdef CONFIG_FAULT_INJECTION
1733 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1734 * balance_dirty_pages() for some dirty throttling pause
1737 int nr_dirtied_pause;
1738 unsigned long dirty_paused_when; /* start of a write-and-pause period */
1740 #ifdef CONFIG_LATENCYTOP
1741 int latency_record_count;
1742 struct latency_record latency_record[LT_SAVECOUNT];
1745 * time slack values; these are used to round up poll() and
1746 * select() etc timeout values. These are in nanoseconds.
1748 unsigned long timer_slack_ns;
1749 unsigned long default_timer_slack_ns;
1752 unsigned int kasan_depth;
1754 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1755 /* Index of current stored address in ret_stack */
1757 /* Stack of return addresses for return function tracing */
1758 struct ftrace_ret_stack *ret_stack;
1759 /* time stamp for last schedule */
1760 unsigned long long ftrace_timestamp;
1762 * Number of functions that haven't been traced
1763 * because of depth overrun.
1765 atomic_t trace_overrun;
1766 /* Pause for the tracing */
1767 atomic_t tracing_graph_pause;
1769 #ifdef CONFIG_TRACING
1770 /* state flags for use by tracers */
1771 unsigned long trace;
1772 /* bitmask and counter of trace recursion */
1773 unsigned long trace_recursion;
1774 #endif /* CONFIG_TRACING */
1776 struct memcg_oom_info {
1777 struct mem_cgroup *memcg;
1780 unsigned int may_oom:1;
1783 #ifdef CONFIG_UPROBES
1784 struct uprobe_task *utask;
1786 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1787 unsigned int sequential_io;
1788 unsigned int sequential_io_avg;
1790 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1791 unsigned long task_state_change;
1793 int pagefault_disabled;
1796 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1797 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1799 #define TNF_MIGRATED 0x01
1800 #define TNF_NO_GROUP 0x02
1801 #define TNF_SHARED 0x04
1802 #define TNF_FAULT_LOCAL 0x08
1803 #define TNF_MIGRATE_FAIL 0x10
1805 #ifdef CONFIG_NUMA_BALANCING
1806 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1807 extern pid_t task_numa_group_id(struct task_struct *p);
1808 extern void set_numabalancing_state(bool enabled);
1809 extern void task_numa_free(struct task_struct *p);
1810 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1811 int src_nid, int dst_cpu);
1813 static inline void task_numa_fault(int last_node, int node, int pages,
1817 static inline pid_t task_numa_group_id(struct task_struct *p)
1821 static inline void set_numabalancing_state(bool enabled)
1824 static inline void task_numa_free(struct task_struct *p)
1827 static inline bool should_numa_migrate_memory(struct task_struct *p,
1828 struct page *page, int src_nid, int dst_cpu)
1834 static inline struct pid *task_pid(struct task_struct *task)
1836 return task->pids[PIDTYPE_PID].pid;
1839 static inline struct pid *task_tgid(struct task_struct *task)
1841 return task->group_leader->pids[PIDTYPE_PID].pid;
1845 * Without tasklist or rcu lock it is not safe to dereference
1846 * the result of task_pgrp/task_session even if task == current,
1847 * we can race with another thread doing sys_setsid/sys_setpgid.
1849 static inline struct pid *task_pgrp(struct task_struct *task)
1851 return task->group_leader->pids[PIDTYPE_PGID].pid;
1854 static inline struct pid *task_session(struct task_struct *task)
1856 return task->group_leader->pids[PIDTYPE_SID].pid;
1859 struct pid_namespace;
1862 * the helpers to get the task's different pids as they are seen
1863 * from various namespaces
1865 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1866 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1868 * task_xid_nr_ns() : id seen from the ns specified;
1870 * set_task_vxid() : assigns a virtual id to a task;
1872 * see also pid_nr() etc in include/linux/pid.h
1874 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1875 struct pid_namespace *ns);
1877 static inline pid_t task_pid_nr(struct task_struct *tsk)
1882 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1883 struct pid_namespace *ns)
1885 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1888 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1890 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1894 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1899 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1901 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1903 return pid_vnr(task_tgid(tsk));
1907 static inline int pid_alive(const struct task_struct *p);
1908 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1914 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1920 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1922 return task_ppid_nr_ns(tsk, &init_pid_ns);
1925 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1926 struct pid_namespace *ns)
1928 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1931 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1933 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1937 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1938 struct pid_namespace *ns)
1940 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1943 static inline pid_t task_session_vnr(struct task_struct *tsk)
1945 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1948 /* obsolete, do not use */
1949 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1951 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1955 * pid_alive - check that a task structure is not stale
1956 * @p: Task structure to be checked.
1958 * Test if a process is not yet dead (at most zombie state)
1959 * If pid_alive fails, then pointers within the task structure
1960 * can be stale and must not be dereferenced.
1962 * Return: 1 if the process is alive. 0 otherwise.
1964 static inline int pid_alive(const struct task_struct *p)
1966 return p->pids[PIDTYPE_PID].pid != NULL;
1970 * is_global_init - check if a task structure is init
1971 * @tsk: Task structure to be checked.
1973 * Check if a task structure is the first user space task the kernel created.
1975 * Return: 1 if the task structure is init. 0 otherwise.
1977 static inline int is_global_init(struct task_struct *tsk)
1979 return tsk->pid == 1;
1982 extern struct pid *cad_pid;
1984 extern void free_task(struct task_struct *tsk);
1985 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1987 extern void __put_task_struct(struct task_struct *t);
1989 static inline void put_task_struct(struct task_struct *t)
1991 if (atomic_dec_and_test(&t->usage))
1992 __put_task_struct(t);
1995 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1996 extern void task_cputime(struct task_struct *t,
1997 cputime_t *utime, cputime_t *stime);
1998 extern void task_cputime_scaled(struct task_struct *t,
1999 cputime_t *utimescaled, cputime_t *stimescaled);
2000 extern cputime_t task_gtime(struct task_struct *t);
2002 static inline void task_cputime(struct task_struct *t,
2003 cputime_t *utime, cputime_t *stime)
2011 static inline void task_cputime_scaled(struct task_struct *t,
2012 cputime_t *utimescaled,
2013 cputime_t *stimescaled)
2016 *utimescaled = t->utimescaled;
2018 *stimescaled = t->stimescaled;
2021 static inline cputime_t task_gtime(struct task_struct *t)
2026 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2027 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2032 #define PF_EXITING 0x00000004 /* getting shut down */
2033 #define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
2034 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
2035 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
2036 #define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
2037 #define PF_MCE_PROCESS 0x00000080 /* process policy on mce errors */
2038 #define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
2039 #define PF_DUMPCORE 0x00000200 /* dumped core */
2040 #define PF_SIGNALED 0x00000400 /* killed by a signal */
2041 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
2042 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user noticed that RLIMIT_NPROC was exceeded */
2043 #define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
2044 #define PF_USED_ASYNC 0x00004000 /* used async_schedule*(), used by module init */
2045 #define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
2046 #define PF_FROZEN 0x00010000 /* frozen for system suspend */
2047 #define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
2048 #define PF_KSWAPD 0x00040000 /* I am kswapd */
2049 #define PF_MEMALLOC_NOIO 0x00080000 /* Allocating memory without IO involved */
2050 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
2051 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
2052 #define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
2053 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
2054 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
2055 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
2056 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
2057 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
2058 #define PF_SUSPEND_TASK 0x80000000 /* this thread called freeze_processes and should not be frozen */
2061 * Only the _current_ task can read/write to tsk->flags, but other
2062 * tasks can access tsk->flags in readonly mode for example
2063 * with tsk_used_math (like during threaded core dumping).
2064 * There is however an exception to this rule during ptrace
2065 * or during fork: the ptracer task is allowed to write to the
2066 * child->flags of its traced child (same goes for fork, the parent
2067 * can write to the child->flags), because we're guaranteed the
2068 * child is not running and in turn not changing child->flags
2069 * at the same time the parent does it.
2071 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2072 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2073 #define clear_used_math() clear_stopped_child_used_math(current)
2074 #define set_used_math() set_stopped_child_used_math(current)
2075 #define conditional_stopped_child_used_math(condition, child) \
2076 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2077 #define conditional_used_math(condition) \
2078 conditional_stopped_child_used_math(condition, current)
2079 #define copy_to_stopped_child_used_math(child) \
2080 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2081 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2082 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2083 #define used_math() tsk_used_math(current)
2085 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2086 * __GFP_FS is also cleared as it implies __GFP_IO.
2088 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2090 if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2091 flags &= ~(__GFP_IO | __GFP_FS);
2095 static inline unsigned int memalloc_noio_save(void)
2097 unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2098 current->flags |= PF_MEMALLOC_NOIO;
2102 static inline void memalloc_noio_restore(unsigned int flags)
2104 current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2107 /* Per-process atomic flags. */
2108 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
2109 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
2110 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
2113 #define TASK_PFA_TEST(name, func) \
2114 static inline bool task_##func(struct task_struct *p) \
2115 { return test_bit(PFA_##name, &p->atomic_flags); }
2116 #define TASK_PFA_SET(name, func) \
2117 static inline void task_set_##func(struct task_struct *p) \
2118 { set_bit(PFA_##name, &p->atomic_flags); }
2119 #define TASK_PFA_CLEAR(name, func) \
2120 static inline void task_clear_##func(struct task_struct *p) \
2121 { clear_bit(PFA_##name, &p->atomic_flags); }
2123 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2124 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2126 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2127 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2128 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2130 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2131 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2132 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2135 * task->jobctl flags
2137 #define JOBCTL_STOP_SIGMASK 0xffff /* signr of the last group stop */
2139 #define JOBCTL_STOP_DEQUEUED_BIT 16 /* stop signal dequeued */
2140 #define JOBCTL_STOP_PENDING_BIT 17 /* task should stop for group stop */
2141 #define JOBCTL_STOP_CONSUME_BIT 18 /* consume group stop count */
2142 #define JOBCTL_TRAP_STOP_BIT 19 /* trap for STOP */
2143 #define JOBCTL_TRAP_NOTIFY_BIT 20 /* trap for NOTIFY */
2144 #define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
2145 #define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
2147 #define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2148 #define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT)
2149 #define JOBCTL_STOP_CONSUME (1UL << JOBCTL_STOP_CONSUME_BIT)
2150 #define JOBCTL_TRAP_STOP (1UL << JOBCTL_TRAP_STOP_BIT)
2151 #define JOBCTL_TRAP_NOTIFY (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2152 #define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT)
2153 #define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT)
2155 #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2156 #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2158 extern bool task_set_jobctl_pending(struct task_struct *task,
2159 unsigned long mask);
2160 extern void task_clear_jobctl_trapping(struct task_struct *task);
2161 extern void task_clear_jobctl_pending(struct task_struct *task,
2162 unsigned long mask);
2164 static inline void rcu_copy_process(struct task_struct *p)
2166 #ifdef CONFIG_PREEMPT_RCU
2167 p->rcu_read_lock_nesting = 0;
2168 p->rcu_read_unlock_special.s = 0;
2169 p->rcu_blocked_node = NULL;
2170 INIT_LIST_HEAD(&p->rcu_node_entry);
2171 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2172 #ifdef CONFIG_TASKS_RCU
2173 p->rcu_tasks_holdout = false;
2174 INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2175 p->rcu_tasks_idle_cpu = -1;
2176 #endif /* #ifdef CONFIG_TASKS_RCU */
2179 static inline void tsk_restore_flags(struct task_struct *task,
2180 unsigned long orig_flags, unsigned long flags)
2182 task->flags &= ~flags;
2183 task->flags |= orig_flags & flags;
2186 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2187 const struct cpumask *trial);
2188 extern int task_can_attach(struct task_struct *p,
2189 const struct cpumask *cs_cpus_allowed);
2191 extern void do_set_cpus_allowed(struct task_struct *p,
2192 const struct cpumask *new_mask);
2194 extern int set_cpus_allowed_ptr(struct task_struct *p,
2195 const struct cpumask *new_mask);
2197 static inline void do_set_cpus_allowed(struct task_struct *p,
2198 const struct cpumask *new_mask)
2201 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2202 const struct cpumask *new_mask)
2204 if (!cpumask_test_cpu(0, new_mask))
2210 #ifdef CONFIG_NO_HZ_COMMON
2211 void calc_load_enter_idle(void);
2212 void calc_load_exit_idle(void);
2214 static inline void calc_load_enter_idle(void) { }
2215 static inline void calc_load_exit_idle(void) { }
2216 #endif /* CONFIG_NO_HZ_COMMON */
2218 #ifndef CONFIG_CPUMASK_OFFSTACK
2219 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2221 return set_cpus_allowed_ptr(p, &new_mask);
2226 * Do not use outside of architecture code which knows its limitations.
2228 * sched_clock() has no promise of monotonicity or bounded drift between
2229 * CPUs, use (which you should not) requires disabling IRQs.
2231 * Please use one of the three interfaces below.
2233 extern unsigned long long notrace sched_clock(void);
2235 * See the comment in kernel/sched/clock.c
2237 extern u64 cpu_clock(int cpu);
2238 extern u64 local_clock(void);
2239 extern u64 running_clock(void);
2240 extern u64 sched_clock_cpu(int cpu);
2243 extern void sched_clock_init(void);
2245 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2246 static inline void sched_clock_tick(void)
2250 static inline void sched_clock_idle_sleep_event(void)
2254 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2259 * Architectures can set this to 1 if they have specified
2260 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2261 * but then during bootup it turns out that sched_clock()
2262 * is reliable after all:
2264 extern int sched_clock_stable(void);
2265 extern void set_sched_clock_stable(void);
2266 extern void clear_sched_clock_stable(void);
2268 extern void sched_clock_tick(void);
2269 extern void sched_clock_idle_sleep_event(void);
2270 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2273 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2275 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2276 * The reason for this explicit opt-in is not to have perf penalty with
2277 * slow sched_clocks.
2279 extern void enable_sched_clock_irqtime(void);
2280 extern void disable_sched_clock_irqtime(void);
2282 static inline void enable_sched_clock_irqtime(void) {}
2283 static inline void disable_sched_clock_irqtime(void) {}
2286 extern unsigned long long
2287 task_sched_runtime(struct task_struct *task);
2289 /* sched_exec is called by processes performing an exec */
2291 extern void sched_exec(void);
2293 #define sched_exec() {}
2296 extern void sched_clock_idle_sleep_event(void);
2297 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2299 #ifdef CONFIG_HOTPLUG_CPU
2300 extern void idle_task_exit(void);
2302 static inline void idle_task_exit(void) {}
2305 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2306 extern void wake_up_nohz_cpu(int cpu);
2308 static inline void wake_up_nohz_cpu(int cpu) { }
2311 #ifdef CONFIG_NO_HZ_FULL
2312 extern bool sched_can_stop_tick(void);
2313 extern u64 scheduler_tick_max_deferment(void);
2315 static inline bool sched_can_stop_tick(void) { return false; }
2318 #ifdef CONFIG_SCHED_AUTOGROUP
2319 extern void sched_autogroup_create_attach(struct task_struct *p);
2320 extern void sched_autogroup_detach(struct task_struct *p);
2321 extern void sched_autogroup_fork(struct signal_struct *sig);
2322 extern void sched_autogroup_exit(struct signal_struct *sig);
2323 #ifdef CONFIG_PROC_FS
2324 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2325 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2328 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2329 static inline void sched_autogroup_detach(struct task_struct *p) { }
2330 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2331 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2334 extern int yield_to(struct task_struct *p, bool preempt);
2335 extern void set_user_nice(struct task_struct *p, long nice);
2336 extern int task_prio(const struct task_struct *p);
2338 * task_nice - return the nice value of a given task.
2339 * @p: the task in question.
2341 * Return: The nice value [ -20 ... 0 ... 19 ].
2343 static inline int task_nice(const struct task_struct *p)
2345 return PRIO_TO_NICE((p)->static_prio);
2347 extern int can_nice(const struct task_struct *p, const int nice);
2348 extern int task_curr(const struct task_struct *p);
2349 extern int idle_cpu(int cpu);
2350 extern int sched_setscheduler(struct task_struct *, int,
2351 const struct sched_param *);
2352 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2353 const struct sched_param *);
2354 extern int sched_setattr(struct task_struct *,
2355 const struct sched_attr *);
2356 extern struct task_struct *idle_task(int cpu);
2358 * is_idle_task - is the specified task an idle task?
2359 * @p: the task in question.
2361 * Return: 1 if @p is an idle task. 0 otherwise.
2363 static inline bool is_idle_task(const struct task_struct *p)
2367 extern struct task_struct *curr_task(int cpu);
2368 extern void set_curr_task(int cpu, struct task_struct *p);
2372 union thread_union {
2373 struct thread_info thread_info;
2374 unsigned long stack[THREAD_SIZE/sizeof(long)];
2377 #ifndef __HAVE_ARCH_KSTACK_END
2378 static inline int kstack_end(void *addr)
2380 /* Reliable end of stack detection:
2381 * Some APM bios versions misalign the stack
2383 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2387 extern union thread_union init_thread_union;
2388 extern struct task_struct init_task;
2390 extern struct mm_struct init_mm;
2392 extern struct pid_namespace init_pid_ns;
2395 * find a task by one of its numerical ids
2397 * find_task_by_pid_ns():
2398 * finds a task by its pid in the specified namespace
2399 * find_task_by_vpid():
2400 * finds a task by its virtual pid
2402 * see also find_vpid() etc in include/linux/pid.h
2405 extern struct task_struct *find_task_by_vpid(pid_t nr);
2406 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2407 struct pid_namespace *ns);
2409 /* per-UID process charging. */
2410 extern struct user_struct * alloc_uid(kuid_t);
2411 static inline struct user_struct *get_uid(struct user_struct *u)
2413 atomic_inc(&u->__count);
2416 extern void free_uid(struct user_struct *);
2418 #include <asm/current.h>
2420 extern void xtime_update(unsigned long ticks);
2422 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2423 extern int wake_up_process(struct task_struct *tsk);
2424 extern void wake_up_new_task(struct task_struct *tsk);
2426 extern void kick_process(struct task_struct *tsk);
2428 static inline void kick_process(struct task_struct *tsk) { }
2430 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2431 extern void sched_dead(struct task_struct *p);
2433 extern void proc_caches_init(void);
2434 extern void flush_signals(struct task_struct *);
2435 extern void __flush_signals(struct task_struct *);
2436 extern void ignore_signals(struct task_struct *);
2437 extern void flush_signal_handlers(struct task_struct *, int force_default);
2438 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2440 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2442 unsigned long flags;
2445 spin_lock_irqsave(&tsk->sighand->siglock, flags);
2446 ret = dequeue_signal(tsk, mask, info);
2447 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2452 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2454 extern void unblock_all_signals(void);
2455 extern void release_task(struct task_struct * p);
2456 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2457 extern int force_sigsegv(int, struct task_struct *);
2458 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2459 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2460 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2461 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2462 const struct cred *, u32);
2463 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2464 extern int kill_pid(struct pid *pid, int sig, int priv);
2465 extern int kill_proc_info(int, struct siginfo *, pid_t);
2466 extern __must_check bool do_notify_parent(struct task_struct *, int);
2467 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2468 extern void force_sig(int, struct task_struct *);
2469 extern int send_sig(int, struct task_struct *, int);
2470 extern int zap_other_threads(struct task_struct *p);
2471 extern struct sigqueue *sigqueue_alloc(void);
2472 extern void sigqueue_free(struct sigqueue *);
2473 extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group);
2474 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2476 static inline void restore_saved_sigmask(void)
2478 if (test_and_clear_restore_sigmask())
2479 __set_current_blocked(¤t->saved_sigmask);
2482 static inline sigset_t *sigmask_to_save(void)
2484 sigset_t *res = ¤t->blocked;
2485 if (unlikely(test_restore_sigmask()))
2486 res = ¤t->saved_sigmask;
2490 static inline int kill_cad_pid(int sig, int priv)
2492 return kill_pid(cad_pid, sig, priv);
2495 /* These can be the second arg to send_sig_info/send_group_sig_info. */
2496 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2497 #define SEND_SIG_PRIV ((struct siginfo *) 1)
2498 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2501 * True if we are on the alternate signal stack.
2503 static inline int on_sig_stack(unsigned long sp)
2505 #ifdef CONFIG_STACK_GROWSUP
2506 return sp >= current->sas_ss_sp &&
2507 sp - current->sas_ss_sp < current->sas_ss_size;
2509 return sp > current->sas_ss_sp &&
2510 sp - current->sas_ss_sp <= current->sas_ss_size;
2514 static inline int sas_ss_flags(unsigned long sp)
2516 if (!current->sas_ss_size)
2519 return on_sig_stack(sp) ? SS_ONSTACK : 0;
2522 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2524 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2525 #ifdef CONFIG_STACK_GROWSUP
2526 return current->sas_ss_sp;
2528 return current->sas_ss_sp + current->sas_ss_size;
2534 * Routines for handling mm_structs
2536 extern struct mm_struct * mm_alloc(void);
2538 /* mmdrop drops the mm and the page tables */
2539 extern void __mmdrop(struct mm_struct *);
2540 static inline void mmdrop(struct mm_struct * mm)
2542 if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2546 /* mmput gets rid of the mappings and all user-space */
2547 extern void mmput(struct mm_struct *);
2548 /* Grab a reference to a task's mm, if it is not already going away */
2549 extern struct mm_struct *get_task_mm(struct task_struct *task);
2551 * Grab a reference to a task's mm, if it is not already going away
2552 * and ptrace_may_access with the mode parameter passed to it
2555 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2556 /* Remove the current tasks stale references to the old mm_struct */
2557 extern void mm_release(struct task_struct *, struct mm_struct *);
2559 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2560 struct task_struct *);
2561 extern void flush_thread(void);
2562 extern void exit_thread(void);
2564 extern void exit_files(struct task_struct *);
2565 extern void __cleanup_sighand(struct sighand_struct *);
2567 extern void exit_itimers(struct signal_struct *);
2568 extern void flush_itimer_signals(void);
2570 extern void do_group_exit(int);
2572 extern int do_execve(struct filename *,
2573 const char __user * const __user *,
2574 const char __user * const __user *);
2575 extern int do_execveat(int, struct filename *,
2576 const char __user * const __user *,
2577 const char __user * const __user *,
2579 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2580 struct task_struct *fork_idle(int);
2581 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2583 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2584 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2586 __set_task_comm(tsk, from, false);
2588 extern char *get_task_comm(char *to, struct task_struct *tsk);
2591 void scheduler_ipi(void);
2592 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2594 static inline void scheduler_ipi(void) { }
2595 static inline unsigned long wait_task_inactive(struct task_struct *p,
2602 #define tasklist_empty() \
2603 list_empty(&init_task.tasks)
2605 #define next_task(p) \
2606 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2608 #define for_each_process(p) \
2609 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2611 extern bool current_is_single_threaded(void);
2614 * Careful: do_each_thread/while_each_thread is a double loop so
2615 * 'break' will not work as expected - use goto instead.
2617 #define do_each_thread(g, t) \
2618 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2620 #define while_each_thread(g, t) \
2621 while ((t = next_thread(t)) != g)
2623 #define __for_each_thread(signal, t) \
2624 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2626 #define for_each_thread(p, t) \
2627 __for_each_thread((p)->signal, t)
2629 /* Careful: this is a double loop, 'break' won't work as expected. */
2630 #define for_each_process_thread(p, t) \
2631 for_each_process(p) for_each_thread(p, t)
2633 static inline int get_nr_threads(struct task_struct *tsk)
2635 return tsk->signal->nr_threads;
2638 static inline bool thread_group_leader(struct task_struct *p)
2640 return p->exit_signal >= 0;
2643 /* Do to the insanities of de_thread it is possible for a process
2644 * to have the pid of the thread group leader without actually being
2645 * the thread group leader. For iteration through the pids in proc
2646 * all we care about is that we have a task with the appropriate
2647 * pid, we don't actually care if we have the right task.
2649 static inline bool has_group_leader_pid(struct task_struct *p)
2651 return task_pid(p) == p->signal->leader_pid;
2655 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2657 return p1->signal == p2->signal;
2660 static inline struct task_struct *next_thread(const struct task_struct *p)
2662 return list_entry_rcu(p->thread_group.next,
2663 struct task_struct, thread_group);
2666 static inline int thread_group_empty(struct task_struct *p)
2668 return list_empty(&p->thread_group);
2671 #define delay_group_leader(p) \
2672 (thread_group_leader(p) && !thread_group_empty(p))
2675 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2676 * subscriptions and synchronises with wait4(). Also used in procfs. Also
2677 * pins the final release of task.io_context. Also protects ->cpuset and
2678 * ->cgroup.subsys[]. And ->vfork_done.
2680 * Nests both inside and outside of read_lock(&tasklist_lock).
2681 * It must not be nested with write_lock_irq(&tasklist_lock),
2682 * neither inside nor outside.
2684 static inline void task_lock(struct task_struct *p)
2686 spin_lock(&p->alloc_lock);
2689 static inline void task_unlock(struct task_struct *p)
2691 spin_unlock(&p->alloc_lock);
2694 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2695 unsigned long *flags);
2697 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2698 unsigned long *flags)
2700 struct sighand_struct *ret;
2702 ret = __lock_task_sighand(tsk, flags);
2703 (void)__cond_lock(&tsk->sighand->siglock, ret);
2707 static inline void unlock_task_sighand(struct task_struct *tsk,
2708 unsigned long *flags)
2710 spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2713 #ifdef CONFIG_CGROUPS
2714 static inline void threadgroup_change_begin(struct task_struct *tsk)
2716 down_read(&tsk->signal->group_rwsem);
2718 static inline void threadgroup_change_end(struct task_struct *tsk)
2720 up_read(&tsk->signal->group_rwsem);
2724 * threadgroup_lock - lock threadgroup
2725 * @tsk: member task of the threadgroup to lock
2727 * Lock the threadgroup @tsk belongs to. No new task is allowed to enter
2728 * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2729 * change ->group_leader/pid. This is useful for cases where the threadgroup
2730 * needs to stay stable across blockable operations.
2732 * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2733 * synchronization. While held, no new task will be added to threadgroup
2734 * and no existing live task will have its PF_EXITING set.
2736 * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2737 * sub-thread becomes a new leader.
2739 static inline void threadgroup_lock(struct task_struct *tsk)
2741 down_write(&tsk->signal->group_rwsem);
2745 * threadgroup_unlock - unlock threadgroup
2746 * @tsk: member task of the threadgroup to unlock
2748 * Reverse threadgroup_lock().
2750 static inline void threadgroup_unlock(struct task_struct *tsk)
2752 up_write(&tsk->signal->group_rwsem);
2755 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2756 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2757 static inline void threadgroup_lock(struct task_struct *tsk) {}
2758 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2761 #ifndef __HAVE_THREAD_FUNCTIONS
2763 #define task_thread_info(task) ((struct thread_info *)(task)->stack)
2764 #define task_stack_page(task) ((task)->stack)
2766 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2768 *task_thread_info(p) = *task_thread_info(org);
2769 task_thread_info(p)->task = p;
2773 * Return the address of the last usable long on the stack.
2775 * When the stack grows down, this is just above the thread
2776 * info struct. Going any lower will corrupt the threadinfo.
2778 * When the stack grows up, this is the highest address.
2779 * Beyond that position, we corrupt data on the next page.
2781 static inline unsigned long *end_of_stack(struct task_struct *p)
2783 #ifdef CONFIG_STACK_GROWSUP
2784 return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2786 return (unsigned long *)(task_thread_info(p) + 1);
2791 #define task_stack_end_corrupted(task) \
2792 (*(end_of_stack(task)) != STACK_END_MAGIC)
2794 static inline int object_is_on_stack(void *obj)
2796 void *stack = task_stack_page(current);
2798 return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2801 extern void thread_info_cache_init(void);
2803 #ifdef CONFIG_DEBUG_STACK_USAGE
2804 static inline unsigned long stack_not_used(struct task_struct *p)
2806 unsigned long *n = end_of_stack(p);
2808 do { /* Skip over canary */
2812 return (unsigned long)n - (unsigned long)end_of_stack(p);
2815 extern void set_task_stack_end_magic(struct task_struct *tsk);
2817 /* set thread flags in other task's structures
2818 * - see asm/thread_info.h for TIF_xxxx flags available
2820 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2822 set_ti_thread_flag(task_thread_info(tsk), flag);
2825 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2827 clear_ti_thread_flag(task_thread_info(tsk), flag);
2830 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2832 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2835 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2837 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2840 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2842 return test_ti_thread_flag(task_thread_info(tsk), flag);
2845 static inline void set_tsk_need_resched(struct task_struct *tsk)
2847 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2850 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2852 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2855 static inline int test_tsk_need_resched(struct task_struct *tsk)
2857 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2860 static inline int restart_syscall(void)
2862 set_tsk_thread_flag(current, TIF_SIGPENDING);
2863 return -ERESTARTNOINTR;
2866 static inline int signal_pending(struct task_struct *p)
2868 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2871 static inline int __fatal_signal_pending(struct task_struct *p)
2873 return unlikely(sigismember(&p->pending.signal, SIGKILL));
2876 static inline int fatal_signal_pending(struct task_struct *p)
2878 return signal_pending(p) && __fatal_signal_pending(p);
2881 static inline int signal_pending_state(long state, struct task_struct *p)
2883 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2885 if (!signal_pending(p))
2888 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2892 * cond_resched() and cond_resched_lock(): latency reduction via
2893 * explicit rescheduling in places that are safe. The return
2894 * value indicates whether a reschedule was done in fact.
2895 * cond_resched_lock() will drop the spinlock before scheduling,
2896 * cond_resched_softirq() will enable bhs before scheduling.
2898 extern int _cond_resched(void);
2900 #define cond_resched() ({ \
2901 ___might_sleep(__FILE__, __LINE__, 0); \
2905 extern int __cond_resched_lock(spinlock_t *lock);
2907 #ifdef CONFIG_PREEMPT_COUNT
2908 #define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET
2910 #define PREEMPT_LOCK_OFFSET 0
2913 #define cond_resched_lock(lock) ({ \
2914 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2915 __cond_resched_lock(lock); \
2918 extern int __cond_resched_softirq(void);
2920 #define cond_resched_softirq() ({ \
2921 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
2922 __cond_resched_softirq(); \
2925 static inline void cond_resched_rcu(void)
2927 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2935 * Does a critical section need to be broken due to another
2936 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2937 * but a general need for low latency)
2939 static inline int spin_needbreak(spinlock_t *lock)
2941 #ifdef CONFIG_PREEMPT
2942 return spin_is_contended(lock);
2949 * Idle thread specific functions to determine the need_resched
2952 #ifdef TIF_POLLING_NRFLAG
2953 static inline int tsk_is_polling(struct task_struct *p)
2955 return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2958 static inline void __current_set_polling(void)
2960 set_thread_flag(TIF_POLLING_NRFLAG);
2963 static inline bool __must_check current_set_polling_and_test(void)
2965 __current_set_polling();
2968 * Polling state must be visible before we test NEED_RESCHED,
2969 * paired by resched_curr()
2971 smp_mb__after_atomic();
2973 return unlikely(tif_need_resched());
2976 static inline void __current_clr_polling(void)
2978 clear_thread_flag(TIF_POLLING_NRFLAG);
2981 static inline bool __must_check current_clr_polling_and_test(void)
2983 __current_clr_polling();
2986 * Polling state must be visible before we test NEED_RESCHED,
2987 * paired by resched_curr()
2989 smp_mb__after_atomic();
2991 return unlikely(tif_need_resched());
2995 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2996 static inline void __current_set_polling(void) { }
2997 static inline void __current_clr_polling(void) { }
2999 static inline bool __must_check current_set_polling_and_test(void)
3001 return unlikely(tif_need_resched());
3003 static inline bool __must_check current_clr_polling_and_test(void)
3005 return unlikely(tif_need_resched());
3009 static inline void current_clr_polling(void)
3011 __current_clr_polling();
3014 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3015 * Once the bit is cleared, we'll get IPIs with every new
3016 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3019 smp_mb(); /* paired with resched_curr() */
3021 preempt_fold_need_resched();
3024 static __always_inline bool need_resched(void)
3026 return unlikely(tif_need_resched());
3030 * Thread group CPU time accounting.
3032 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3033 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3036 * Reevaluate whether the task has signals pending delivery.
3037 * Wake the task if so.
3038 * This is required every time the blocked sigset_t changes.
3039 * callers must hold sighand->siglock.
3041 extern void recalc_sigpending_and_wake(struct task_struct *t);
3042 extern void recalc_sigpending(void);
3044 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3046 static inline void signal_wake_up(struct task_struct *t, bool resume)
3048 signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3050 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3052 signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3056 * Wrappers for p->thread_info->cpu access. No-op on UP.
3060 static inline unsigned int task_cpu(const struct task_struct *p)
3062 return task_thread_info(p)->cpu;
3065 static inline int task_node(const struct task_struct *p)
3067 return cpu_to_node(task_cpu(p));
3070 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3074 static inline unsigned int task_cpu(const struct task_struct *p)
3079 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3083 #endif /* CONFIG_SMP */
3085 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3086 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3088 #ifdef CONFIG_CGROUP_SCHED
3089 extern struct task_group root_task_group;
3090 #endif /* CONFIG_CGROUP_SCHED */
3092 extern int task_can_switch_user(struct user_struct *up,
3093 struct task_struct *tsk);
3095 #ifdef CONFIG_TASK_XACCT
3096 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3098 tsk->ioac.rchar += amt;
3101 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3103 tsk->ioac.wchar += amt;
3106 static inline void inc_syscr(struct task_struct *tsk)
3111 static inline void inc_syscw(struct task_struct *tsk)
3116 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3120 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3124 static inline void inc_syscr(struct task_struct *tsk)
3128 static inline void inc_syscw(struct task_struct *tsk)
3133 #ifndef TASK_SIZE_OF
3134 #define TASK_SIZE_OF(tsk) TASK_SIZE
3138 extern void mm_update_next_owner(struct mm_struct *mm);
3140 static inline void mm_update_next_owner(struct mm_struct *mm)
3143 #endif /* CONFIG_MEMCG */
3145 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3148 return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3151 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3154 return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3157 static inline unsigned long rlimit(unsigned int limit)
3159 return task_rlimit(current, limit);
3162 static inline unsigned long rlimit_max(unsigned int limit)
3164 return task_rlimit_max(current, limit);