Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/include/linux/sched.h

  1 #ifndef _LINUX_SCHED_H
  2 #define _LINUX_SCHED_H
  3 
  4 #include <uapi/linux/sched.h>
  5 
  6 #include <linux/sched/prio.h>
  7 
  8 
  9 struct sched_param {
 10         int sched_priority;
 11 };
 12 
 13 #include <asm/param.h>  /* for HZ */
 14 
 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>
 29 
 30 #include <asm/page.h>
 31 #include <asm/ptrace.h>
 32 #include <linux/cputime.h>
 33 
 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/seccomp.h>
 44 #include <linux/rcupdate.h>
 45 #include <linux/rculist.h>
 46 #include <linux/rtmutex.h>
 47 
 48 #include <linux/time.h>
 49 #include <linux/param.h>
 50 #include <linux/resource.h>
 51 #include <linux/timer.h>
 52 #include <linux/hrtimer.h>
 53 #include <linux/kcov.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>
 61 #include <linux/cgroup-defs.h>
 62 
 63 #include <asm/processor.h>
 64 
 65 #define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
 66 
 67 /*
 68  * Extended scheduling parameters data structure.
 69  *
 70  * This is needed because the original struct sched_param can not be
 71  * altered without introducing ABI issues with legacy applications
 72  * (e.g., in sched_getparam()).
 73  *
 74  * However, the possibility of specifying more than just a priority for
 75  * the tasks may be useful for a wide variety of application fields, e.g.,
 76  * multimedia, streaming, automation and control, and many others.
 77  *
 78  * This variant (sched_attr) is meant at describing a so-called
 79  * sporadic time-constrained task. In such model a task is specified by:
 80  *  - the activation period or minimum instance inter-arrival time;
 81  *  - the maximum (or average, depending on the actual scheduling
 82  *    discipline) computation time of all instances, a.k.a. runtime;
 83  *  - the deadline (relative to the actual activation time) of each
 84  *    instance.
 85  * Very briefly, a periodic (sporadic) task asks for the execution of
 86  * some specific computation --which is typically called an instance--
 87  * (at most) every period. Moreover, each instance typically lasts no more
 88  * than the runtime and must be completed by time instant t equal to
 89  * the instance activation time + the deadline.
 90  *
 91  * This is reflected by the actual fields of the sched_attr structure:
 92  *
 93  *  @size               size of the structure, for fwd/bwd compat.
 94  *
 95  *  @sched_policy       task's scheduling policy
 96  *  @sched_flags        for customizing the scheduler behaviour
 97  *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
 98  *  @sched_priority     task's static priority (SCHED_FIFO/RR)
 99  *  @sched_deadline     representative of the task's deadline
100  *  @sched_runtime      representative of the task's runtime
101  *  @sched_period       representative of the task's period
102  *
103  * Given this task model, there are a multiplicity of scheduling algorithms
104  * and policies, that can be used to ensure all the tasks will make their
105  * timing constraints.
106  *
107  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
108  * only user of this new interface. More information about the algorithm
109  * available in the scheduling class file or in Documentation/.
110  */
111 struct sched_attr {
112         u32 size;
113 
114         u32 sched_policy;
115         u64 sched_flags;
116 
117         /* SCHED_NORMAL, SCHED_BATCH */
118         s32 sched_nice;
119 
120         /* SCHED_FIFO, SCHED_RR */
121         u32 sched_priority;
122 
123         /* SCHED_DEADLINE */
124         u64 sched_runtime;
125         u64 sched_deadline;
126         u64 sched_period;
127 };
128 
129 struct futex_pi_state;
130 struct robust_list_head;
131 struct bio_list;
132 struct fs_struct;
133 struct perf_event_context;
134 struct blk_plug;
135 struct filename;
136 struct nameidata;
137 
138 #define VMACACHE_BITS 2
139 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
140 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
141 
142 /*
143  * These are the constant used to fake the fixed-point load-average
144  * counting. Some notes:
145  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
146  *    a load-average precision of 10 bits integer + 11 bits fractional
147  *  - if you want to count load-averages more often, you need more
148  *    precision, or rounding will get you. With 2-second counting freq,
149  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
150  *    11 bit fractions.
151  */
152 extern unsigned long avenrun[];         /* Load averages */
153 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
154 
155 #define FSHIFT          11              /* nr of bits of precision */
156 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
157 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
158 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
159 #define EXP_5           2014            /* 1/exp(5sec/5min) */
160 #define EXP_15          2037            /* 1/exp(5sec/15min) */
161 
162 #define CALC_LOAD(load,exp,n) \
163         load *= exp; \
164         load += n*(FIXED_1-exp); \
165         load >>= FSHIFT;
166 
167 extern unsigned long total_forks;
168 extern int nr_threads;
169 DECLARE_PER_CPU(unsigned long, process_counts);
170 extern int nr_processes(void);
171 extern unsigned long nr_running(void);
172 extern bool single_task_running(void);
173 extern unsigned long nr_iowait(void);
174 extern unsigned long nr_iowait_cpu(int cpu);
175 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
176 
177 extern void calc_global_load(unsigned long ticks);
178 
179 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
180 extern void cpu_load_update_nohz_start(void);
181 extern void cpu_load_update_nohz_stop(void);
182 #else
183 static inline void cpu_load_update_nohz_start(void) { }
184 static inline void cpu_load_update_nohz_stop(void) { }
185 #endif
186 
187 extern void dump_cpu_task(int cpu);
188 
189 struct seq_file;
190 struct cfs_rq;
191 struct task_group;
192 #ifdef CONFIG_SCHED_DEBUG
193 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
194 extern void proc_sched_set_task(struct task_struct *p);
195 #endif
196 
197 /*
198  * Task state bitmask. NOTE! These bits are also
199  * encoded in fs/proc/array.c: get_task_state().
200  *
201  * We have two separate sets of flags: task->state
202  * is about runnability, while task->exit_state are
203  * about the task exiting. Confusing, but this way
204  * modifying one set can't modify the other one by
205  * mistake.
206  */
207 #define TASK_RUNNING            0
208 #define TASK_INTERRUPTIBLE      1
209 #define TASK_UNINTERRUPTIBLE    2
210 #define __TASK_STOPPED          4
211 #define __TASK_TRACED           8
212 /* in tsk->exit_state */
213 #define EXIT_DEAD               16
214 #define EXIT_ZOMBIE             32
215 #define EXIT_TRACE              (EXIT_ZOMBIE | EXIT_DEAD)
216 /* in tsk->state again */
217 #define TASK_DEAD               64
218 #define TASK_WAKEKILL           128
219 #define TASK_WAKING             256
220 #define TASK_PARKED             512
221 #define TASK_NOLOAD             1024
222 #define TASK_NEW                2048
223 #define TASK_STATE_MAX          4096
224 
225 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
226 
227 extern char ___assert_task_state[1 - 2*!!(
228                 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
229 
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)
234 
235 #define TASK_IDLE               (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
236 
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)
240 
241 /* get_task_state() */
242 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
243                                  TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
244                                  __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
245 
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)
254 
255 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
256 
257 #define __set_task_state(tsk, state_value)                      \
258         do {                                                    \
259                 (tsk)->task_state_change = _THIS_IP_;           \
260                 (tsk)->state = (state_value);                   \
261         } while (0)
262 #define set_task_state(tsk, state_value)                        \
263         do {                                                    \
264                 (tsk)->task_state_change = _THIS_IP_;           \
265                 smp_store_mb((tsk)->state, (state_value));      \
266         } while (0)
267 
268 #define __set_current_state(state_value)                        \
269         do {                                                    \
270                 current->task_state_change = _THIS_IP_;         \
271                 current->state = (state_value);                 \
272         } while (0)
273 #define set_current_state(state_value)                          \
274         do {                                                    \
275                 current->task_state_change = _THIS_IP_;         \
276                 smp_store_mb(current->state, (state_value));    \
277         } while (0)
278 
279 #else
280 
281 /*
282  * @tsk had better be current, or you get to keep the pieces.
283  *
284  * The only reason is that computing current can be more expensive than
285  * using a pointer that's already available.
286  *
287  * Therefore, see set_current_state().
288  */
289 #define __set_task_state(tsk, state_value)              \
290         do { (tsk)->state = (state_value); } while (0)
291 #define set_task_state(tsk, state_value)                \
292         smp_store_mb((tsk)->state, (state_value))
293 
294 /*
295  * set_current_state() includes a barrier so that the write of current->state
296  * is correctly serialised wrt the caller's subsequent test of whether to
297  * actually sleep:
298  *
299  *   for (;;) {
300  *      set_current_state(TASK_UNINTERRUPTIBLE);
301  *      if (!need_sleep)
302  *              break;
303  *
304  *      schedule();
305  *   }
306  *   __set_current_state(TASK_RUNNING);
307  *
308  * If the caller does not need such serialisation (because, for instance, the
309  * condition test and condition change and wakeup are under the same lock) then
310  * use __set_current_state().
311  *
312  * The above is typically ordered against the wakeup, which does:
313  *
314  *      need_sleep = false;
315  *      wake_up_state(p, TASK_UNINTERRUPTIBLE);
316  *
317  * Where wake_up_state() (and all other wakeup primitives) imply enough
318  * barriers to order the store of the variable against wakeup.
319  *
320  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
321  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
322  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
323  *
324  * This is obviously fine, since they both store the exact same value.
325  *
326  * Also see the comments of try_to_wake_up().
327  */
328 #define __set_current_state(state_value)                \
329         do { current->state = (state_value); } while (0)
330 #define set_current_state(state_value)                  \
331         smp_store_mb(current->state, (state_value))
332 
333 #endif
334 
335 /* Task command name length */
336 #define TASK_COMM_LEN 16
337 
338 #include <linux/spinlock.h>
339 
340 /*
341  * This serializes "schedule()" and also protects
342  * the run-queue from deletions/modifications (but
343  * _adding_ to the beginning of the run-queue has
344  * a separate lock).
345  */
346 extern rwlock_t tasklist_lock;
347 extern spinlock_t mmlist_lock;
348 
349 struct task_struct;
350 
351 #ifdef CONFIG_PROVE_RCU
352 extern int lockdep_tasklist_lock_is_held(void);
353 #endif /* #ifdef CONFIG_PROVE_RCU */
354 
355 extern void sched_init(void);
356 extern void sched_init_smp(void);
357 extern asmlinkage void schedule_tail(struct task_struct *prev);
358 extern void init_idle(struct task_struct *idle, int cpu);
359 extern void init_idle_bootup_task(struct task_struct *idle);
360 
361 extern cpumask_var_t cpu_isolated_map;
362 
363 extern int runqueue_is_locked(int cpu);
364 
365 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
366 extern void nohz_balance_enter_idle(int cpu);
367 extern void set_cpu_sd_state_idle(void);
368 extern int get_nohz_timer_target(void);
369 #else
370 static inline void nohz_balance_enter_idle(int cpu) { }
371 static inline void set_cpu_sd_state_idle(void) { }
372 #endif
373 
374 /*
375  * Only dump TASK_* tasks. (0 for all tasks)
376  */
377 extern void show_state_filter(unsigned long state_filter);
378 
379 static inline void show_state(void)
380 {
381         show_state_filter(0);
382 }
383 
384 extern void show_regs(struct pt_regs *);
385 
386 /*
387  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
388  * task), SP is the stack pointer of the first frame that should be shown in the back
389  * trace (or NULL if the entire call-chain of the task should be shown).
390  */
391 extern void show_stack(struct task_struct *task, unsigned long *sp);
392 
393 extern void cpu_init (void);
394 extern void trap_init(void);
395 extern void update_process_times(int user);
396 extern void scheduler_tick(void);
397 extern int sched_cpu_starting(unsigned int cpu);
398 extern int sched_cpu_activate(unsigned int cpu);
399 extern int sched_cpu_deactivate(unsigned int cpu);
400 
401 #ifdef CONFIG_HOTPLUG_CPU
402 extern int sched_cpu_dying(unsigned int cpu);
403 #else
404 # define sched_cpu_dying        NULL
405 #endif
406 
407 extern void sched_show_task(struct task_struct *p);
408 
409 #ifdef CONFIG_LOCKUP_DETECTOR
410 extern void touch_softlockup_watchdog_sched(void);
411 extern void touch_softlockup_watchdog(void);
412 extern void touch_softlockup_watchdog_sync(void);
413 extern void touch_all_softlockup_watchdogs(void);
414 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
415                                   void __user *buffer,
416                                   size_t *lenp, loff_t *ppos);
417 extern unsigned int  softlockup_panic;
418 extern unsigned int  hardlockup_panic;
419 void lockup_detector_init(void);
420 #else
421 static inline void touch_softlockup_watchdog_sched(void)
422 {
423 }
424 static inline void touch_softlockup_watchdog(void)
425 {
426 }
427 static inline void touch_softlockup_watchdog_sync(void)
428 {
429 }
430 static inline void touch_all_softlockup_watchdogs(void)
431 {
432 }
433 static inline void lockup_detector_init(void)
434 {
435 }
436 #endif
437 
438 #ifdef CONFIG_DETECT_HUNG_TASK
439 void reset_hung_task_detector(void);
440 #else
441 static inline void reset_hung_task_detector(void)
442 {
443 }
444 #endif
445 
446 /* Attach to any functions which should be ignored in wchan output. */
447 #define __sched         __attribute__((__section__(".sched.text")))
448 
449 /* Linker adds these: start and end of __sched functions */
450 extern char __sched_text_start[], __sched_text_end[];
451 
452 /* Is this address in the __sched functions? */
453 extern int in_sched_functions(unsigned long addr);
454 
455 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
456 extern signed long schedule_timeout(signed long timeout);
457 extern signed long schedule_timeout_interruptible(signed long timeout);
458 extern signed long schedule_timeout_killable(signed long timeout);
459 extern signed long schedule_timeout_uninterruptible(signed long timeout);
460 extern signed long schedule_timeout_idle(signed long timeout);
461 asmlinkage void schedule(void);
462 extern void schedule_preempt_disabled(void);
463 
464 extern long io_schedule_timeout(long timeout);
465 
466 static inline void io_schedule(void)
467 {
468         io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
469 }
470 
471 void __noreturn do_task_dead(void);
472 
473 struct nsproxy;
474 struct user_namespace;
475 
476 #ifdef CONFIG_MMU
477 extern void arch_pick_mmap_layout(struct mm_struct *mm);
478 extern unsigned long
479 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
480                        unsigned long, unsigned long);
481 extern unsigned long
482 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
483                           unsigned long len, unsigned long pgoff,
484                           unsigned long flags);
485 #else
486 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
487 #endif
488 
489 #define SUID_DUMP_DISABLE       0       /* No setuid dumping */
490 #define SUID_DUMP_USER          1       /* Dump as user of process */
491 #define SUID_DUMP_ROOT          2       /* Dump as root */
492 
493 /* mm flags */
494 
495 /* for SUID_DUMP_* above */
496 #define MMF_DUMPABLE_BITS 2
497 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
498 
499 extern void set_dumpable(struct mm_struct *mm, int value);
500 /*
501  * This returns the actual value of the suid_dumpable flag. For things
502  * that are using this for checking for privilege transitions, it must
503  * test against SUID_DUMP_USER rather than treating it as a boolean
504  * value.
505  */
506 static inline int __get_dumpable(unsigned long mm_flags)
507 {
508         return mm_flags & MMF_DUMPABLE_MASK;
509 }
510 
511 static inline int get_dumpable(struct mm_struct *mm)
512 {
513         return __get_dumpable(mm->flags);
514 }
515 
516 /* coredump filter bits */
517 #define MMF_DUMP_ANON_PRIVATE   2
518 #define MMF_DUMP_ANON_SHARED    3
519 #define MMF_DUMP_MAPPED_PRIVATE 4
520 #define MMF_DUMP_MAPPED_SHARED  5
521 #define MMF_DUMP_ELF_HEADERS    6
522 #define MMF_DUMP_HUGETLB_PRIVATE 7
523 #define MMF_DUMP_HUGETLB_SHARED  8
524 #define MMF_DUMP_DAX_PRIVATE    9
525 #define MMF_DUMP_DAX_SHARED     10
526 
527 #define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
528 #define MMF_DUMP_FILTER_BITS    9
529 #define MMF_DUMP_FILTER_MASK \
530         (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
531 #define MMF_DUMP_FILTER_DEFAULT \
532         ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
533          (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
534 
535 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
536 # define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
537 #else
538 # define MMF_DUMP_MASK_DEFAULT_ELF      0
539 #endif
540                                         /* leave room for more dump flags */
541 #define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
542 #define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
543 /*
544  * This one-shot flag is dropped due to necessity of changing exe once again
545  * on NFS restore
546  */
547 //#define MMF_EXE_FILE_CHANGED  18      /* see prctl_set_mm_exe_file() */
548 
549 #define MMF_HAS_UPROBES         19      /* has uprobes */
550 #define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
551 #define MMF_OOM_SKIP            21      /* mm is of no interest for the OOM killer */
552 #define MMF_UNSTABLE            22      /* mm is unstable for copy_from_user */
553 #define MMF_HUGE_ZERO_PAGE      23      /* mm has ever used the global huge zero page */
554 
555 #define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
556 
557 struct sighand_struct {
558         atomic_t                count;
559         struct k_sigaction      action[_NSIG];
560         spinlock_t              siglock;
561         wait_queue_head_t       signalfd_wqh;
562 };
563 
564 struct pacct_struct {
565         int                     ac_flag;
566         long                    ac_exitcode;
567         unsigned long           ac_mem;
568         cputime_t               ac_utime, ac_stime;
569         unsigned long           ac_minflt, ac_majflt;
570 };
571 
572 struct cpu_itimer {
573         cputime_t expires;
574         cputime_t incr;
575         u32 error;
576         u32 incr_error;
577 };
578 
579 /**
580  * struct prev_cputime - snaphsot of system and user cputime
581  * @utime: time spent in user mode
582  * @stime: time spent in system mode
583  * @lock: protects the above two fields
584  *
585  * Stores previous user/system time values such that we can guarantee
586  * monotonicity.
587  */
588 struct prev_cputime {
589 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
590         cputime_t utime;
591         cputime_t stime;
592         raw_spinlock_t lock;
593 #endif
594 };
595 
596 static inline void prev_cputime_init(struct prev_cputime *prev)
597 {
598 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
599         prev->utime = prev->stime = 0;
600         raw_spin_lock_init(&prev->lock);
601 #endif
602 }
603 
604 /**
605  * struct task_cputime - collected CPU time counts
606  * @utime:              time spent in user mode, in &cputime_t units
607  * @stime:              time spent in kernel mode, in &cputime_t units
608  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
609  *
610  * This structure groups together three kinds of CPU time that are tracked for
611  * threads and thread groups.  Most things considering CPU time want to group
612  * these counts together and treat all three of them in parallel.
613  */
614 struct task_cputime {
615         cputime_t utime;
616         cputime_t stime;
617         unsigned long long sum_exec_runtime;
618 };
619 
620 /* Alternate field names when used to cache expirations. */
621 #define virt_exp        utime
622 #define prof_exp        stime
623 #define sched_exp       sum_exec_runtime
624 
625 #define INIT_CPUTIME    \
626         (struct task_cputime) {                                 \
627                 .utime = 0,                                     \
628                 .stime = 0,                                     \
629                 .sum_exec_runtime = 0,                          \
630         }
631 
632 /*
633  * This is the atomic variant of task_cputime, which can be used for
634  * storing and updating task_cputime statistics without locking.
635  */
636 struct task_cputime_atomic {
637         atomic64_t utime;
638         atomic64_t stime;
639         atomic64_t sum_exec_runtime;
640 };
641 
642 #define INIT_CPUTIME_ATOMIC \
643         (struct task_cputime_atomic) {                          \
644                 .utime = ATOMIC64_INIT(0),                      \
645                 .stime = ATOMIC64_INIT(0),                      \
646                 .sum_exec_runtime = ATOMIC64_INIT(0),           \
647         }
648 
649 #define PREEMPT_DISABLED        (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
650 
651 /*
652  * Disable preemption until the scheduler is running -- use an unconditional
653  * value so that it also works on !PREEMPT_COUNT kernels.
654  *
655  * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
656  */
657 #define INIT_PREEMPT_COUNT      PREEMPT_OFFSET
658 
659 /*
660  * Initial preempt_count value; reflects the preempt_count schedule invariant
661  * which states that during context switches:
662  *
663  *    preempt_count() == 2*PREEMPT_DISABLE_OFFSET
664  *
665  * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
666  * Note: See finish_task_switch().
667  */
668 #define FORK_PREEMPT_COUNT      (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
669 
670 /**
671  * struct thread_group_cputimer - thread group interval timer counts
672  * @cputime_atomic:     atomic thread group interval timers.
673  * @running:            true when there are timers running and
674  *                      @cputime_atomic receives updates.
675  * @checking_timer:     true when a thread in the group is in the
676  *                      process of checking for thread group timers.
677  *
678  * This structure contains the version of task_cputime, above, that is
679  * used for thread group CPU timer calculations.
680  */
681 struct thread_group_cputimer {
682         struct task_cputime_atomic cputime_atomic;
683         bool running;
684         bool checking_timer;
685 };
686 
687 #include <linux/rwsem.h>
688 struct autogroup;
689 
690 /*
691  * NOTE! "signal_struct" does not have its own
692  * locking, because a shared signal_struct always
693  * implies a shared sighand_struct, so locking
694  * sighand_struct is always a proper superset of
695  * the locking of signal_struct.
696  */
697 struct signal_struct {
698         atomic_t                sigcnt;
699         atomic_t                live;
700         int                     nr_threads;
701         struct list_head        thread_head;
702 
703         wait_queue_head_t       wait_chldexit;  /* for wait4() */
704 
705         /* current thread group signal load-balancing target: */
706         struct task_struct      *curr_target;
707 
708         /* shared signal handling: */
709         struct sigpending       shared_pending;
710 
711         /* thread group exit support */
712         int                     group_exit_code;
713         /* overloaded:
714          * - notify group_exit_task when ->count is equal to notify_count
715          * - everyone except group_exit_task is stopped during signal delivery
716          *   of fatal signals, group_exit_task processes the signal.
717          */
718         int                     notify_count;
719         struct task_struct      *group_exit_task;
720 
721         /* thread group stop support, overloads group_exit_code too */
722         int                     group_stop_count;
723         unsigned int            flags; /* see SIGNAL_* flags below */
724 
725         /*
726          * PR_SET_CHILD_SUBREAPER marks a process, like a service
727          * manager, to re-parent orphan (double-forking) child processes
728          * to this process instead of 'init'. The service manager is
729          * able to receive SIGCHLD signals and is able to investigate
730          * the process until it calls wait(). All children of this
731          * process will inherit a flag if they should look for a
732          * child_subreaper process at exit.
733          */
734         unsigned int            is_child_subreaper:1;
735         unsigned int            has_child_subreaper:1;
736 
737         /* POSIX.1b Interval Timers */
738         int                     posix_timer_id;
739         struct list_head        posix_timers;
740 
741         /* ITIMER_REAL timer for the process */
742         struct hrtimer real_timer;
743         struct pid *leader_pid;
744         ktime_t it_real_incr;
745 
746         /*
747          * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
748          * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
749          * values are defined to 0 and 1 respectively
750          */
751         struct cpu_itimer it[2];
752 
753         /*
754          * Thread group totals for process CPU timers.
755          * See thread_group_cputimer(), et al, for details.
756          */
757         struct thread_group_cputimer cputimer;
758 
759         /* Earliest-expiration cache. */
760         struct task_cputime cputime_expires;
761 
762 #ifdef CONFIG_NO_HZ_FULL
763         atomic_t tick_dep_mask;
764 #endif
765 
766         struct list_head cpu_timers[3];
767 
768         struct pid *tty_old_pgrp;
769 
770         /* boolean value for session group leader */
771         int leader;
772 
773         struct tty_struct *tty; /* NULL if no tty */
774 
775 #ifdef CONFIG_SCHED_AUTOGROUP
776         struct autogroup *autogroup;
777 #endif
778         /*
779          * Cumulative resource counters for dead threads in the group,
780          * and for reaped dead child processes forked by this group.
781          * Live threads maintain their own counters and add to these
782          * in __exit_signal, except for the group leader.
783          */
784         seqlock_t stats_lock;
785         cputime_t utime, stime, cutime, cstime;
786         cputime_t gtime;
787         cputime_t cgtime;
788         struct prev_cputime prev_cputime;
789         unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
790         unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
791         unsigned long inblock, oublock, cinblock, coublock;
792         unsigned long maxrss, cmaxrss;
793         struct task_io_accounting ioac;
794 
795         /*
796          * Cumulative ns of schedule CPU time fo dead threads in the
797          * group, not including a zombie group leader, (This only differs
798          * from jiffies_to_ns(utime + stime) if sched_clock uses something
799          * other than jiffies.)
800          */
801         unsigned long long sum_sched_runtime;
802 
803         /*
804          * We don't bother to synchronize most readers of this at all,
805          * because there is no reader checking a limit that actually needs
806          * to get both rlim_cur and rlim_max atomically, and either one
807          * alone is a single word that can safely be read normally.
808          * getrlimit/setrlimit use task_lock(current->group_leader) to
809          * protect this instead of the siglock, because they really
810          * have no need to disable irqs.
811          */
812         struct rlimit rlim[RLIM_NLIMITS];
813 
814 #ifdef CONFIG_BSD_PROCESS_ACCT
815         struct pacct_struct pacct;      /* per-process accounting information */
816 #endif
817 #ifdef CONFIG_TASKSTATS
818         struct taskstats *stats;
819 #endif
820 #ifdef CONFIG_AUDIT
821         unsigned audit_tty;
822         struct tty_audit_buf *tty_audit_buf;
823 #endif
824 
825         /*
826          * Thread is the potential origin of an oom condition; kill first on
827          * oom
828          */
829         bool oom_flag_origin;
830         short oom_score_adj;            /* OOM kill score adjustment */
831         short oom_score_adj_min;        /* OOM kill score adjustment min value.
832                                          * Only settable by CAP_SYS_RESOURCE. */
833         struct mm_struct *oom_mm;       /* recorded mm when the thread group got
834                                          * killed by the oom killer */
835 
836         struct mutex cred_guard_mutex;  /* guard against foreign influences on
837                                          * credential calculations
838                                          * (notably. ptrace) */
839 };
840 
841 /*
842  * Bits in flags field of signal_struct.
843  */
844 #define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
845 #define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
846 #define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
847 #define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
848 /*
849  * Pending notifications to parent.
850  */
851 #define SIGNAL_CLD_STOPPED      0x00000010
852 #define SIGNAL_CLD_CONTINUED    0x00000020
853 #define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
854 
855 #define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
856 
857 #define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
858                           SIGNAL_STOP_CONTINUED)
859 
860 static inline void signal_set_stop_flags(struct signal_struct *sig,
861                                          unsigned int flags)
862 {
863         WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP));
864         sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
865 }
866 
867 /* If true, all threads except ->group_exit_task have pending SIGKILL */
868 static inline int signal_group_exit(const struct signal_struct *sig)
869 {
870         return  (sig->flags & SIGNAL_GROUP_EXIT) ||
871                 (sig->group_exit_task != NULL);
872 }
873 
874 /*
875  * Some day this will be a full-fledged user tracking system..
876  */
877 struct user_struct {
878         atomic_t __count;       /* reference count */
879         atomic_t processes;     /* How many processes does this user have? */
880         atomic_t sigpending;    /* How many pending signals does this user have? */
881 #ifdef CONFIG_INOTIFY_USER
882         atomic_t inotify_watches; /* How many inotify watches does this user have? */
883         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
884 #endif
885 #ifdef CONFIG_FANOTIFY
886         atomic_t fanotify_listeners;
887 #endif
888 #ifdef CONFIG_EPOLL
889         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
890 #endif
891 #ifdef CONFIG_POSIX_MQUEUE
892         /* protected by mq_lock */
893         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
894 #endif
895         unsigned long locked_shm; /* How many pages of mlocked shm ? */
896         unsigned long unix_inflight;    /* How many files in flight in unix sockets */
897         atomic_long_t pipe_bufs;  /* how many pages are allocated in pipe buffers */
898 
899 #ifdef CONFIG_KEYS
900         struct key *uid_keyring;        /* UID specific keyring */
901         struct key *session_keyring;    /* UID's default session keyring */
902 #endif
903 
904         /* Hash table maintenance information */
905         struct hlist_node uidhash_node;
906         kuid_t uid;
907 
908 #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL)
909         atomic_long_t locked_vm;
910 #endif
911 };
912 
913 extern int uids_sysfs_init(void);
914 
915 extern struct user_struct *find_user(kuid_t);
916 
917 extern struct user_struct root_user;
918 #define INIT_USER (&root_user)
919 
920 
921 struct backing_dev_info;
922 struct reclaim_state;
923 
924 #ifdef CONFIG_SCHED_INFO
925 struct sched_info {
926         /* cumulative counters */
927         unsigned long pcount;         /* # of times run on this cpu */
928         unsigned long long run_delay; /* time spent waiting on a runqueue */
929 
930         /* timestamps */
931         unsigned long long last_arrival,/* when we last ran on a cpu */
932                            last_queued; /* when we were last queued to run */
933 };
934 #endif /* CONFIG_SCHED_INFO */
935 
936 #ifdef CONFIG_TASK_DELAY_ACCT
937 struct task_delay_info {
938         spinlock_t      lock;
939         unsigned int    flags;  /* Private per-task flags */
940 
941         /* For each stat XXX, add following, aligned appropriately
942          *
943          * struct timespec XXX_start, XXX_end;
944          * u64 XXX_delay;
945          * u32 XXX_count;
946          *
947          * Atomicity of updates to XXX_delay, XXX_count protected by
948          * single lock above (split into XXX_lock if contention is an issue).
949          */
950 
951         /*
952          * XXX_count is incremented on every XXX operation, the delay
953          * associated with the operation is added to XXX_delay.
954          * XXX_delay contains the accumulated delay time in nanoseconds.
955          */
956         u64 blkio_start;        /* Shared by blkio, swapin */
957         u64 blkio_delay;        /* wait for sync block io completion */
958         u64 swapin_delay;       /* wait for swapin block io completion */
959         u32 blkio_count;        /* total count of the number of sync block */
960                                 /* io operations performed */
961         u32 swapin_count;       /* total count of the number of swapin block */
962                                 /* io operations performed */
963 
964         u64 freepages_start;
965         u64 freepages_delay;    /* wait for memory reclaim */
966         u32 freepages_count;    /* total count of memory reclaim */
967 };
968 #endif  /* CONFIG_TASK_DELAY_ACCT */
969 
970 static inline int sched_info_on(void)
971 {
972 #ifdef CONFIG_SCHEDSTATS
973         return 1;
974 #elif defined(CONFIG_TASK_DELAY_ACCT)
975         extern int delayacct_on;
976         return delayacct_on;
977 #else
978         return 0;
979 #endif
980 }
981 
982 #ifdef CONFIG_SCHEDSTATS
983 void force_schedstat_enabled(void);
984 #endif
985 
986 enum cpu_idle_type {
987         CPU_IDLE,
988         CPU_NOT_IDLE,
989         CPU_NEWLY_IDLE,
990         CPU_MAX_IDLE_TYPES
991 };
992 
993 /*
994  * Integer metrics need fixed point arithmetic, e.g., sched/fair
995  * has a few: load, load_avg, util_avg, freq, and capacity.
996  *
997  * We define a basic fixed point arithmetic range, and then formalize
998  * all these metrics based on that basic range.
999  */
1000 # define SCHED_FIXEDPOINT_SHIFT 10
1001 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
1002 
1003 /*
1004  * Increase resolution of cpu_capacity calculations
1005  */
1006 #define SCHED_CAPACITY_SHIFT    SCHED_FIXEDPOINT_SHIFT
1007 #define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
1008 
1009 /*
1010  * Wake-queues are lists of tasks with a pending wakeup, whose
1011  * callers have already marked the task as woken internally,
1012  * and can thus carry on. A common use case is being able to
1013  * do the wakeups once the corresponding user lock as been
1014  * released.
1015  *
1016  * We hold reference to each task in the list across the wakeup,
1017  * thus guaranteeing that the memory is still valid by the time
1018  * the actual wakeups are performed in wake_up_q().
1019  *
1020  * One per task suffices, because there's never a need for a task to be
1021  * in two wake queues simultaneously; it is forbidden to abandon a task
1022  * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
1023  * already in a wake queue, the wakeup will happen soon and the second
1024  * waker can just skip it.
1025  *
1026  * The DEFINE_WAKE_Q macro declares and initializes the list head.
1027  * wake_up_q() does NOT reinitialize the list; it's expected to be
1028  * called near the end of a function, where the fact that the queue is
1029  * not used again will be easy to see by inspection.
1030  *
1031  * Note that this can cause spurious wakeups. schedule() callers
1032  * must ensure the call is done inside a loop, confirming that the
1033  * wakeup condition has in fact occurred.
1034  */
1035 struct wake_q_node {
1036         struct wake_q_node *next;
1037 };
1038 
1039 struct wake_q_head {
1040         struct wake_q_node *first;
1041         struct wake_q_node **lastp;
1042 };
1043 
1044 #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
1045 
1046 #define DEFINE_WAKE_Q(name)                             \
1047         struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
1048 
1049 extern void wake_q_add(struct wake_q_head *head,
1050                        struct task_struct *task);
1051 extern void wake_up_q(struct wake_q_head *head);
1052 
1053 /*
1054  * sched-domains (multiprocessor balancing) declarations:
1055  */
1056 #ifdef CONFIG_SMP
1057 #define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
1058 #define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
1059 #define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
1060 #define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
1061 #define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
1062 #define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
1063 #define SD_ASYM_CPUCAPACITY     0x0040  /* Groups have different max cpu capacities */
1064 #define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu capacity */
1065 #define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
1066 #define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
1067 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
1068 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
1069 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
1070 #define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
1071 #define SD_NUMA                 0x4000  /* cross-node balancing */
1072 
1073 #ifdef CONFIG_SCHED_SMT
1074 static inline int cpu_smt_flags(void)
1075 {
1076         return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
1077 }
1078 #endif
1079 
1080 #ifdef CONFIG_SCHED_MC
1081 static inline int cpu_core_flags(void)
1082 {
1083         return SD_SHARE_PKG_RESOURCES;
1084 }
1085 #endif
1086 
1087 #ifdef CONFIG_NUMA
1088 static inline int cpu_numa_flags(void)
1089 {
1090         return SD_NUMA;
1091 }
1092 #endif
1093 
1094 extern int arch_asym_cpu_priority(int cpu);
1095 
1096 struct sched_domain_attr {
1097         int relax_domain_level;
1098 };
1099 
1100 #define SD_ATTR_INIT    (struct sched_domain_attr) {    \
1101         .relax_domain_level = -1,                       \
1102 }
1103 
1104 extern int sched_domain_level_max;
1105 
1106 struct sched_group;
1107 
1108 struct sched_domain_shared {
1109         atomic_t        ref;
1110         atomic_t        nr_busy_cpus;
1111         int             has_idle_cores;
1112 };
1113 
1114 struct sched_domain {
1115         /* These fields must be setup */
1116         struct sched_domain *parent;    /* top domain must be null terminated */
1117         struct sched_domain *child;     /* bottom domain must be null terminated */
1118         struct sched_group *groups;     /* the balancing groups of the domain */
1119         unsigned long min_interval;     /* Minimum balance interval ms */
1120         unsigned long max_interval;     /* Maximum balance interval ms */
1121         unsigned int busy_factor;       /* less balancing by factor if busy */
1122         unsigned int imbalance_pct;     /* No balance until over watermark */
1123         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
1124         unsigned int busy_idx;
1125         unsigned int idle_idx;
1126         unsigned int newidle_idx;
1127         unsigned int wake_idx;
1128         unsigned int forkexec_idx;
1129         unsigned int smt_gain;
1130 
1131         int nohz_idle;                  /* NOHZ IDLE status */
1132         int flags;                      /* See SD_* */
1133         int level;
1134 
1135         /* Runtime fields. */
1136         unsigned long last_balance;     /* init to jiffies. units in jiffies */
1137         unsigned int balance_interval;  /* initialise to 1. units in ms. */
1138         unsigned int nr_balance_failed; /* initialise to 0 */
1139 
1140         /* idle_balance() stats */
1141         u64 max_newidle_lb_cost;
1142         unsigned long next_decay_max_lb_cost;
1143 
1144         u64 avg_scan_cost;              /* select_idle_sibling */
1145 
1146 #ifdef CONFIG_SCHEDSTATS
1147         /* load_balance() stats */
1148         unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1149         unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1150         unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1151         unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1152         unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1153         unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1154         unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1155         unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1156 
1157         /* Active load balancing */
1158         unsigned int alb_count;
1159         unsigned int alb_failed;
1160         unsigned int alb_pushed;
1161 
1162         /* SD_BALANCE_EXEC stats */
1163         unsigned int sbe_count;
1164         unsigned int sbe_balanced;
1165         unsigned int sbe_pushed;
1166 
1167         /* SD_BALANCE_FORK stats */
1168         unsigned int sbf_count;
1169         unsigned int sbf_balanced;
1170         unsigned int sbf_pushed;
1171 
1172         /* try_to_wake_up() stats */
1173         unsigned int ttwu_wake_remote;
1174         unsigned int ttwu_move_affine;
1175         unsigned int ttwu_move_balance;
1176 #endif
1177 #ifdef CONFIG_SCHED_DEBUG
1178         char *name;
1179 #endif
1180         union {
1181                 void *private;          /* used during construction */
1182                 struct rcu_head rcu;    /* used during destruction */
1183         };
1184         struct sched_domain_shared *shared;
1185 
1186         unsigned int span_weight;
1187         /*
1188          * Span of all CPUs in this domain.
1189          *
1190          * NOTE: this field is variable length. (Allocated dynamically
1191          * by attaching extra space to the end of the structure,
1192          * depending on how many CPUs the kernel has booted up with)
1193          */
1194         unsigned long span[0];
1195 };
1196 
1197 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1198 {
1199         return to_cpumask(sd->span);
1200 }
1201 
1202 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1203                                     struct sched_domain_attr *dattr_new);
1204 
1205 /* Allocate an array of sched domains, for partition_sched_domains(). */
1206 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1207 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1208 
1209 bool cpus_share_cache(int this_cpu, int that_cpu);
1210 
1211 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1212 typedef int (*sched_domain_flags_f)(void);
1213 
1214 #define SDTL_OVERLAP    0x01
1215 
1216 struct sd_data {
1217         struct sched_domain **__percpu sd;
1218         struct sched_domain_shared **__percpu sds;
1219         struct sched_group **__percpu sg;
1220         struct sched_group_capacity **__percpu sgc;
1221 };
1222 
1223 struct sched_domain_topology_level {
1224         sched_domain_mask_f mask;
1225         sched_domain_flags_f sd_flags;
1226         int                 flags;
1227         int                 numa_level;
1228         struct sd_data      data;
1229 #ifdef CONFIG_SCHED_DEBUG
1230         char                *name;
1231 #endif
1232 };
1233 
1234 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1235 extern void wake_up_if_idle(int cpu);
1236 
1237 #ifdef CONFIG_SCHED_DEBUG
1238 # define SD_INIT_NAME(type)             .name = #type
1239 #else
1240 # define SD_INIT_NAME(type)
1241 #endif
1242 
1243 #else /* CONFIG_SMP */
1244 
1245 struct sched_domain_attr;
1246 
1247 static inline void
1248 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1249                         struct sched_domain_attr *dattr_new)
1250 {
1251 }
1252 
1253 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1254 {
1255         return true;
1256 }
1257 
1258 #endif  /* !CONFIG_SMP */
1259 
1260 
1261 struct io_context;                      /* See blkdev.h */
1262 
1263 
1264 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1265 extern void prefetch_stack(struct task_struct *t);
1266 #else
1267 static inline void prefetch_stack(struct task_struct *t) { }
1268 #endif
1269 
1270 struct audit_context;           /* See audit.c */
1271 struct mempolicy;
1272 struct pipe_inode_info;
1273 struct uts_namespace;
1274 
1275 struct load_weight {
1276         unsigned long weight;
1277         u32 inv_weight;
1278 };
1279 
1280 /*
1281  * The load_avg/util_avg accumulates an infinite geometric series
1282  * (see __update_load_avg() in kernel/sched/fair.c).
1283  *
1284  * [load_avg definition]
1285  *
1286  *   load_avg = runnable% * scale_load_down(load)
1287  *
1288  * where runnable% is the time ratio that a sched_entity is runnable.
1289  * For cfs_rq, it is the aggregated load_avg of all runnable and
1290  * blocked sched_entities.
1291  *
1292  * load_avg may also take frequency scaling into account:
1293  *
1294  *   load_avg = runnable% * scale_load_down(load) * freq%
1295  *
1296  * where freq% is the CPU frequency normalized to the highest frequency.
1297  *
1298  * [util_avg definition]
1299  *
1300  *   util_avg = running% * SCHED_CAPACITY_SCALE
1301  *
1302  * where running% is the time ratio that a sched_entity is running on
1303  * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
1304  * and blocked sched_entities.
1305  *
1306  * util_avg may also factor frequency scaling and CPU capacity scaling:
1307  *
1308  *   util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
1309  *
1310  * where freq% is the same as above, and capacity% is the CPU capacity
1311  * normalized to the greatest capacity (due to uarch differences, etc).
1312  *
1313  * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
1314  * themselves are in the range of [0, 1]. To do fixed point arithmetics,
1315  * we therefore scale them to as large a range as necessary. This is for
1316  * example reflected by util_avg's SCHED_CAPACITY_SCALE.
1317  *
1318  * [Overflow issue]
1319  *
1320  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
1321  * with the highest load (=88761), always runnable on a single cfs_rq,
1322  * and should not overflow as the number already hits PID_MAX_LIMIT.
1323  *
1324  * For all other cases (including 32-bit kernels), struct load_weight's
1325  * weight will overflow first before we do, because:
1326  *
1327  *    Max(load_avg) <= Max(load.weight)
1328  *
1329  * Then it is the load_weight's responsibility to consider overflow
1330  * issues.
1331  */
1332 struct sched_avg {
1333         u64 last_update_time, load_sum;
1334         u32 util_sum, period_contrib;
1335         unsigned long load_avg, util_avg;
1336 };
1337 
1338 #ifdef CONFIG_SCHEDSTATS
1339 struct sched_statistics {
1340         u64                     wait_start;
1341         u64                     wait_max;
1342         u64                     wait_count;
1343         u64                     wait_sum;
1344         u64                     iowait_count;
1345         u64                     iowait_sum;
1346 
1347         u64                     sleep_start;
1348         u64                     sleep_max;
1349         s64                     sum_sleep_runtime;
1350 
1351         u64                     block_start;
1352         u64                     block_max;
1353         u64                     exec_max;
1354         u64                     slice_max;
1355 
1356         u64                     nr_migrations_cold;
1357         u64                     nr_failed_migrations_affine;
1358         u64                     nr_failed_migrations_running;
1359         u64                     nr_failed_migrations_hot;
1360         u64                     nr_forced_migrations;
1361 
1362         u64                     nr_wakeups;
1363         u64                     nr_wakeups_sync;
1364         u64                     nr_wakeups_migrate;
1365         u64                     nr_wakeups_local;
1366         u64                     nr_wakeups_remote;
1367         u64                     nr_wakeups_affine;
1368         u64                     nr_wakeups_affine_attempts;
1369         u64                     nr_wakeups_passive;
1370         u64                     nr_wakeups_idle;
1371 };
1372 #endif
1373 
1374 struct sched_entity {
1375         struct load_weight      load;           /* for load-balancing */
1376         struct rb_node          run_node;
1377         struct list_head        group_node;
1378         unsigned int            on_rq;
1379 
1380         u64                     exec_start;
1381         u64                     sum_exec_runtime;
1382         u64                     vruntime;
1383         u64                     prev_sum_exec_runtime;
1384 
1385         u64                     nr_migrations;
1386 
1387 #ifdef CONFIG_SCHEDSTATS
1388         struct sched_statistics statistics;
1389 #endif
1390 
1391 #ifdef CONFIG_FAIR_GROUP_SCHED
1392         int                     depth;
1393         struct sched_entity     *parent;
1394         /* rq on which this entity is (to be) queued: */
1395         struct cfs_rq           *cfs_rq;
1396         /* rq "owned" by this entity/group: */
1397         struct cfs_rq           *my_q;
1398 #endif
1399 
1400 #ifdef CONFIG_SMP
1401         /*
1402          * Per entity load average tracking.
1403          *
1404          * Put into separate cache line so it does not
1405          * collide with read-mostly values above.
1406          */
1407         struct sched_avg        avg ____cacheline_aligned_in_smp;
1408 #endif
1409 };
1410 
1411 struct sched_rt_entity {
1412         struct list_head run_list;
1413         unsigned long timeout;
1414         unsigned long watchdog_stamp;
1415         unsigned int time_slice;
1416         unsigned short on_rq;
1417         unsigned short on_list;
1418 
1419         struct sched_rt_entity *back;
1420 #ifdef CONFIG_RT_GROUP_SCHED
1421         struct sched_rt_entity  *parent;
1422         /* rq on which this entity is (to be) queued: */
1423         struct rt_rq            *rt_rq;
1424         /* rq "owned" by this entity/group: */
1425         struct rt_rq            *my_q;
1426 #endif
1427 };
1428 
1429 struct sched_dl_entity {
1430         struct rb_node  rb_node;
1431 
1432         /*
1433          * Original scheduling parameters. Copied here from sched_attr
1434          * during sched_setattr(), they will remain the same until
1435          * the next sched_setattr().
1436          */
1437         u64 dl_runtime;         /* maximum runtime for each instance    */
1438         u64 dl_deadline;        /* relative deadline of each instance   */
1439         u64 dl_period;          /* separation of two instances (period) */
1440         u64 dl_bw;              /* dl_runtime / dl_deadline             */
1441 
1442         /*
1443          * Actual scheduling parameters. Initialized with the values above,
1444          * they are continously updated during task execution. Note that
1445          * the remaining runtime could be < 0 in case we are in overrun.
1446          */
1447         s64 runtime;            /* remaining runtime for this instance  */
1448         u64 deadline;           /* absolute deadline for this instance  */
1449         unsigned int flags;     /* specifying the scheduler behaviour   */
1450 
1451         /*
1452          * Some bool flags:
1453          *
1454          * @dl_throttled tells if we exhausted the runtime. If so, the
1455          * task has to wait for a replenishment to be performed at the
1456          * next firing of dl_timer.
1457          *
1458          * @dl_boosted tells if we are boosted due to DI. If so we are
1459          * outside bandwidth enforcement mechanism (but only until we
1460          * exit the critical section);
1461          *
1462          * @dl_yielded tells if task gave up the cpu before consuming
1463          * all its available runtime during the last job.
1464          */
1465         int dl_throttled, dl_boosted, dl_yielded;
1466 
1467         /*
1468          * Bandwidth enforcement timer. Each -deadline task has its
1469          * own bandwidth to be enforced, thus we need one timer per task.
1470          */
1471         struct hrtimer dl_timer;
1472 };
1473 
1474 union rcu_special {
1475         struct {
1476                 u8 blocked;
1477                 u8 need_qs;
1478                 u8 exp_need_qs;
1479                 u8 pad; /* Otherwise the compiler can store garbage here. */
1480         } b; /* Bits. */
1481         u32 s; /* Set of bits. */
1482 };
1483 struct rcu_node;
1484 
1485 enum perf_event_task_context {
1486         perf_invalid_context = -1,
1487         perf_hw_context = 0,
1488         perf_sw_context,
1489         perf_nr_task_contexts,
1490 };
1491 
1492 /* Track pages that require TLB flushes */
1493 struct tlbflush_unmap_batch {
1494         /*
1495          * Each bit set is a CPU that potentially has a TLB entry for one of
1496          * the PFNs being flushed. See set_tlb_ubc_flush_pending().
1497          */
1498         struct cpumask cpumask;
1499 
1500         /* True if any bit in cpumask is set */
1501         bool flush_required;
1502 
1503         /*
1504          * If true then the PTE was dirty when unmapped. The entry must be
1505          * flushed before IO is initiated or a stale TLB entry potentially
1506          * allows an update without redirtying the page.
1507          */
1508         bool writable;
1509 };
1510 
1511 struct task_struct {
1512 #ifdef CONFIG_THREAD_INFO_IN_TASK
1513         /*
1514          * For reasons of header soup (see current_thread_info()), this
1515          * must be the first element of task_struct.
1516          */
1517         struct thread_info thread_info;
1518 #endif
1519         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1520         void *stack;
1521         atomic_t usage;
1522         unsigned int flags;     /* per process flags, defined below */
1523         unsigned int ptrace;
1524 
1525 #ifdef CONFIG_SMP
1526         struct llist_node wake_entry;
1527         int on_cpu;
1528 #ifdef CONFIG_THREAD_INFO_IN_TASK
1529         unsigned int cpu;       /* current CPU */
1530 #endif
1531         unsigned int wakee_flips;
1532         unsigned long wakee_flip_decay_ts;
1533         struct task_struct *last_wakee;
1534 
1535         int wake_cpu;
1536 #endif
1537         int on_rq;
1538 
1539         int prio, static_prio, normal_prio;
1540         unsigned int rt_priority;
1541         const struct sched_class *sched_class;
1542         struct sched_entity se;
1543         struct sched_rt_entity rt;
1544 #ifdef CONFIG_CGROUP_SCHED
1545         struct task_group *sched_task_group;
1546 #endif
1547         struct sched_dl_entity dl;
1548 
1549 #ifdef CONFIG_PREEMPT_NOTIFIERS
1550         /* list of struct preempt_notifier: */
1551         struct hlist_head preempt_notifiers;
1552 #endif
1553 
1554 #ifdef CONFIG_BLK_DEV_IO_TRACE
1555         unsigned int btrace_seq;
1556 #endif
1557 
1558         unsigned int policy;
1559         int nr_cpus_allowed;
1560         cpumask_t cpus_allowed;
1561 
1562 #ifdef CONFIG_PREEMPT_RCU
1563         int rcu_read_lock_nesting;
1564         union rcu_special rcu_read_unlock_special;
1565         struct list_head rcu_node_entry;
1566         struct rcu_node *rcu_blocked_node;
1567 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1568 #ifdef CONFIG_TASKS_RCU
1569         unsigned long rcu_tasks_nvcsw;
1570         bool rcu_tasks_holdout;
1571         struct list_head rcu_tasks_holdout_list;
1572         int rcu_tasks_idle_cpu;
1573 #endif /* #ifdef CONFIG_TASKS_RCU */
1574 
1575 #ifdef CONFIG_SCHED_INFO
1576         struct sched_info sched_info;
1577 #endif
1578 
1579         struct list_head tasks;
1580 #ifdef CONFIG_SMP
1581         struct plist_node pushable_tasks;
1582         struct rb_node pushable_dl_tasks;
1583 #endif
1584 
1585         struct mm_struct *mm, *active_mm;
1586         /* per-thread vma caching */
1587         u32 vmacache_seqnum;
1588         struct vm_area_struct *vmacache[VMACACHE_SIZE];
1589 #if defined(SPLIT_RSS_COUNTING)
1590         struct task_rss_stat    rss_stat;
1591 #endif
1592 /* task state */
1593         int exit_state;
1594         int exit_code, exit_signal;
1595         int pdeath_signal;  /*  The signal sent when the parent dies  */
1596         unsigned long jobctl;   /* JOBCTL_*, siglock protected */
1597 
1598         /* Used for emulating ABI behavior of previous Linux versions */
1599         unsigned int personality;
1600 
1601         /* scheduler bits, serialized by scheduler locks */
1602         unsigned sched_reset_on_fork:1;
1603         unsigned sched_contributes_to_load:1;
1604         unsigned sched_migrated:1;
1605         unsigned sched_remote_wakeup:1;
1606         unsigned :0; /* force alignment to the next boundary */
1607 
1608         /* unserialized, strictly 'current' */
1609         unsigned in_execve:1; /* bit to tell LSMs we're in execve */
1610         unsigned in_iowait:1;
1611 #if !defined(TIF_RESTORE_SIGMASK)
1612         unsigned restore_sigmask:1;
1613 #endif
1614 #ifdef CONFIG_MEMCG
1615         unsigned memcg_may_oom:1;
1616 #ifndef CONFIG_SLOB
1617         unsigned memcg_kmem_skip_account:1;
1618 #endif
1619 #endif
1620 #ifdef CONFIG_COMPAT_BRK
1621         unsigned brk_randomized:1;
1622 #endif
1623 
1624         unsigned long atomic_flags; /* Flags needing atomic access. */
1625 
1626         struct restart_block restart_block;
1627 
1628         pid_t pid;
1629         pid_t tgid;
1630 
1631 #ifdef CONFIG_CC_STACKPROTECTOR
1632         /* Canary value for the -fstack-protector gcc feature */
1633         unsigned long stack_canary;
1634 #endif
1635         /*
1636          * pointers to (original) parent process, youngest child, younger sibling,
1637          * older sibling, respectively.  (p->father can be replaced with
1638          * p->real_parent->pid)
1639          */
1640         struct task_struct __rcu *real_parent; /* real parent process */
1641         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1642         /*
1643          * children/sibling forms the list of my natural children
1644          */
1645         struct list_head children;      /* list of my children */
1646         struct list_head sibling;       /* linkage in my parent's children list */
1647         struct task_struct *group_leader;       /* threadgroup leader */
1648 
1649         /*
1650          * ptraced is the list of tasks this task is using ptrace on.
1651          * This includes both natural children and PTRACE_ATTACH targets.
1652          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1653          */
1654         struct list_head ptraced;
1655         struct list_head ptrace_entry;
1656 
1657         /* PID/PID hash table linkage. */
1658         struct pid_link pids[PIDTYPE_MAX];
1659         struct list_head thread_group;
1660         struct list_head thread_node;
1661 
1662         struct completion *vfork_done;          /* for vfork() */
1663         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1664         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1665 
1666         cputime_t utime, stime;
1667 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1668         cputime_t utimescaled, stimescaled;
1669 #endif
1670         cputime_t gtime;
1671         struct prev_cputime prev_cputime;
1672 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1673         seqcount_t vtime_seqcount;
1674         unsigned long long vtime_snap;
1675         enum {
1676                 /* Task is sleeping or running in a CPU with VTIME inactive */
1677                 VTIME_INACTIVE = 0,
1678                 /* Task runs in userspace in a CPU with VTIME active */
1679                 VTIME_USER,
1680                 /* Task runs in kernelspace in a CPU with VTIME active */
1681                 VTIME_SYS,
1682         } vtime_snap_whence;
1683 #endif
1684 
1685 #ifdef CONFIG_NO_HZ_FULL
1686         atomic_t tick_dep_mask;
1687 #endif
1688         unsigned long nvcsw, nivcsw; /* context switch counts */
1689         u64 start_time;         /* monotonic time in nsec */
1690         u64 real_start_time;    /* boot based time in nsec */
1691 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1692         unsigned long min_flt, maj_flt;
1693 
1694         struct task_cputime cputime_expires;
1695         struct list_head cpu_timers[3];
1696 
1697 /* process credentials */
1698         const struct cred __rcu *ptracer_cred; /* Tracer's credentials at attach */
1699         const struct cred __rcu *real_cred; /* objective and real subjective task
1700                                          * credentials (COW) */
1701         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1702                                          * credentials (COW) */
1703         char comm[TASK_COMM_LEN]; /* executable name excluding path
1704                                      - access with [gs]et_task_comm (which lock
1705                                        it with task_lock())
1706                                      - initialized normally by setup_new_exec */
1707 /* file system info */
1708         struct nameidata *nameidata;
1709 #ifdef CONFIG_SYSVIPC
1710 /* ipc stuff */
1711         struct sysv_sem sysvsem;
1712         struct sysv_shm sysvshm;
1713 #endif
1714 #ifdef CONFIG_DETECT_HUNG_TASK
1715 /* hung task detection */
1716         unsigned long last_switch_count;
1717 #endif
1718 /* filesystem information */
1719         struct fs_struct *fs;
1720 /* open file information */
1721         struct files_struct *files;
1722 /* namespaces */
1723         struct nsproxy *nsproxy;
1724 /* signal handlers */
1725         struct signal_struct *signal;
1726         struct sighand_struct *sighand;
1727 
1728         sigset_t blocked, real_blocked;
1729         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1730         struct sigpending pending;
1731 
1732         unsigned long sas_ss_sp;
1733         size_t sas_ss_size;
1734         unsigned sas_ss_flags;
1735 
1736         struct callback_head *task_works;
1737 
1738         struct audit_context *audit_context;
1739 #ifdef CONFIG_AUDITSYSCALL
1740         kuid_t loginuid;
1741         unsigned int sessionid;
1742 #endif
1743         struct seccomp seccomp;
1744 
1745 /* Thread group tracking */
1746         u32 parent_exec_id;
1747         u32 self_exec_id;
1748 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1749  * mempolicy */
1750         spinlock_t alloc_lock;
1751 
1752         /* Protection of the PI data structures: */
1753         raw_spinlock_t pi_lock;
1754 
1755         struct wake_q_node wake_q;
1756 
1757 #ifdef CONFIG_RT_MUTEXES
1758         /* PI waiters blocked on a rt_mutex held by this task */
1759         struct rb_root pi_waiters;
1760         struct rb_node *pi_waiters_leftmost;
1761         /* Deadlock detection and priority inheritance handling */
1762         struct rt_mutex_waiter *pi_blocked_on;
1763 #endif
1764 
1765 #ifdef CONFIG_DEBUG_MUTEXES
1766         /* mutex deadlock detection */
1767         struct mutex_waiter *blocked_on;
1768 #endif
1769 #ifdef CONFIG_TRACE_IRQFLAGS
1770         unsigned int irq_events;
1771         unsigned long hardirq_enable_ip;
1772         unsigned long hardirq_disable_ip;
1773         unsigned int hardirq_enable_event;
1774         unsigned int hardirq_disable_event;
1775         int hardirqs_enabled;
1776         int hardirq_context;
1777         unsigned long softirq_disable_ip;
1778         unsigned long softirq_enable_ip;
1779         unsigned int softirq_disable_event;
1780         unsigned int softirq_enable_event;
1781         int softirqs_enabled;
1782         int softirq_context;
1783 #endif
1784 #ifdef CONFIG_LOCKDEP
1785 # define MAX_LOCK_DEPTH 48UL
1786         u64 curr_chain_key;
1787         int lockdep_depth;
1788         unsigned int lockdep_recursion;
1789         struct held_lock held_locks[MAX_LOCK_DEPTH];
1790         gfp_t lockdep_reclaim_gfp;
1791 #endif
1792 #ifdef CONFIG_UBSAN
1793         unsigned int in_ubsan;
1794 #endif
1795 
1796 /* journalling filesystem info */
1797         void *journal_info;
1798 
1799 /* stacked block device info */
1800         struct bio_list *bio_list;
1801 
1802 #ifdef CONFIG_BLOCK
1803 /* stack plugging */
1804         struct blk_plug *plug;
1805 #endif
1806 
1807 /* VM state */
1808         struct reclaim_state *reclaim_state;
1809 
1810         struct backing_dev_info *backing_dev_info;
1811 
1812         struct io_context *io_context;
1813 
1814         unsigned long ptrace_message;
1815         siginfo_t *last_siginfo; /* For ptrace use.  */
1816         struct task_io_accounting ioac;
1817 #if defined(CONFIG_TASK_XACCT)
1818         u64 acct_rss_mem1;      /* accumulated rss usage */
1819         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1820         cputime_t acct_timexpd; /* stime + utime since last update */
1821 #endif
1822 #ifdef CONFIG_CPUSETS
1823         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1824         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1825         int cpuset_mem_spread_rotor;
1826         int cpuset_slab_spread_rotor;
1827 #endif
1828 #ifdef CONFIG_CGROUPS
1829         /* Control Group info protected by css_set_lock */
1830         struct css_set __rcu *cgroups;
1831         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1832         struct list_head cg_list;
1833 #endif
1834 #ifdef CONFIG_INTEL_RDT_A
1835         int closid;
1836 #endif
1837 #ifdef CONFIG_FUTEX
1838         struct robust_list_head __user *robust_list;
1839 #ifdef CONFIG_COMPAT
1840         struct compat_robust_list_head __user *compat_robust_list;
1841 #endif
1842         struct list_head pi_state_list;
1843         struct futex_pi_state *pi_state_cache;
1844 #endif
1845 #ifdef CONFIG_PERF_EVENTS
1846         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1847         struct mutex perf_event_mutex;
1848         struct list_head perf_event_list;
1849 #endif
1850 #ifdef CONFIG_DEBUG_PREEMPT
1851         unsigned long preempt_disable_ip;
1852 #endif
1853 #ifdef CONFIG_NUMA
1854         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1855         short il_next;
1856         short pref_node_fork;
1857 #endif
1858 #ifdef CONFIG_NUMA_BALANCING
1859         int numa_scan_seq;
1860         unsigned int numa_scan_period;
1861         unsigned int numa_scan_period_max;
1862         int numa_preferred_nid;
1863         unsigned long numa_migrate_retry;
1864         u64 node_stamp;                 /* migration stamp  */
1865         u64 last_task_numa_placement;
1866         u64 last_sum_exec_runtime;
1867         struct callback_head numa_work;
1868 
1869         struct list_head numa_entry;
1870         struct numa_group *numa_group;
1871 
1872         /*
1873          * numa_faults is an array split into four regions:
1874          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1875          * in this precise order.
1876          *
1877          * faults_memory: Exponential decaying average of faults on a per-node
1878          * basis. Scheduling placement decisions are made based on these
1879          * counts. The values remain static for the duration of a PTE scan.
1880          * faults_cpu: Track the nodes the process was running on when a NUMA
1881          * hinting fault was incurred.
1882          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1883          * during the current scan window. When the scan completes, the counts
1884          * in faults_memory and faults_cpu decay and these values are copied.
1885          */
1886         unsigned long *numa_faults;
1887         unsigned long total_numa_faults;
1888 
1889         /*
1890          * numa_faults_locality tracks if faults recorded during the last
1891          * scan window were remote/local or failed to migrate. The task scan
1892          * period is adapted based on the locality of the faults with different
1893          * weights depending on whether they were shared or private faults
1894          */
1895         unsigned long numa_faults_locality[3];
1896 
1897         unsigned long numa_pages_migrated;
1898 #endif /* CONFIG_NUMA_BALANCING */
1899 
1900 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1901         struct tlbflush_unmap_batch tlb_ubc;
1902 #endif
1903 
1904         struct rcu_head rcu;
1905 
1906         /*
1907          * cache last used pipe for splice
1908          */
1909         struct pipe_inode_info *splice_pipe;
1910 
1911         struct page_frag task_frag;
1912 
1913 #ifdef  CONFIG_TASK_DELAY_ACCT
1914         struct task_delay_info *delays;
1915 #endif
1916 #ifdef CONFIG_FAULT_INJECTION
1917         int make_it_fail;
1918 #endif
1919         /*
1920          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1921          * balance_dirty_pages() for some dirty throttling pause
1922          */
1923         int nr_dirtied;
1924         int nr_dirtied_pause;
1925         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1926 
1927 #ifdef CONFIG_LATENCYTOP
1928         int latency_record_count;
1929         struct latency_record latency_record[LT_SAVECOUNT];
1930 #endif
1931         /*
1932          * time slack values; these are used to round up poll() and
1933          * select() etc timeout values. These are in nanoseconds.
1934          */
1935         u64 timer_slack_ns;
1936         u64 default_timer_slack_ns;
1937 
1938 #ifdef CONFIG_KASAN
1939         unsigned int kasan_depth;
1940 #endif
1941 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1942         /* Index of current stored address in ret_stack */
1943         int curr_ret_stack;
1944         /* Stack of return addresses for return function tracing */
1945         struct ftrace_ret_stack *ret_stack;
1946         /* time stamp for last schedule */
1947         unsigned long long ftrace_timestamp;
1948         /*
1949          * Number of functions that haven't been traced
1950          * because of depth overrun.
1951          */
1952         atomic_t trace_overrun;
1953         /* Pause for the tracing */
1954         atomic_t tracing_graph_pause;
1955 #endif
1956 #ifdef CONFIG_TRACING
1957         /* state flags for use by tracers */
1958         unsigned long trace;
1959         /* bitmask and counter of trace recursion */
1960         unsigned long trace_recursion;
1961 #endif /* CONFIG_TRACING */
1962 #ifdef CONFIG_KCOV
1963         /* Coverage collection mode enabled for this task (0 if disabled). */
1964         enum kcov_mode kcov_mode;
1965         /* Size of the kcov_area. */
1966         unsigned        kcov_size;
1967         /* Buffer for coverage collection. */
1968         void            *kcov_area;
1969         /* kcov desciptor wired with this task or NULL. */
1970         struct kcov     *kcov;
1971 #endif
1972 #ifdef CONFIG_MEMCG
1973         struct mem_cgroup *memcg_in_oom;
1974         gfp_t memcg_oom_gfp_mask;
1975         int memcg_oom_order;
1976 
1977         /* number of pages to reclaim on returning to userland */
1978         unsigned int memcg_nr_pages_over_high;
1979 #endif
1980 #ifdef CONFIG_UPROBES
1981         struct uprobe_task *utask;
1982 #endif
1983 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1984         unsigned int    sequential_io;
1985         unsigned int    sequential_io_avg;
1986 #endif
1987 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1988         unsigned long   task_state_change;
1989 #endif
1990         int pagefault_disabled;
1991 #ifdef CONFIG_MMU
1992         struct task_struct *oom_reaper_list;
1993 #endif
1994 #ifdef CONFIG_VMAP_STACK
1995         struct vm_struct *stack_vm_area;
1996 #endif
1997 #ifdef CONFIG_THREAD_INFO_IN_TASK
1998         /* A live task holds one reference. */
1999         atomic_t stack_refcount;
2000 #endif
2001 /* CPU-specific state of this task */
2002         struct thread_struct thread;
2003 /*
2004  * WARNING: on x86, 'thread_struct' contains a variable-sized
2005  * structure.  It *MUST* be at the end of 'task_struct'.
2006  *
2007  * Do not put anything below here!
2008  */
2009 };
2010 
2011 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
2012 extern int arch_task_struct_size __read_mostly;
2013 #else
2014 # define arch_task_struct_size (sizeof(struct task_struct))
2015 #endif
2016 
2017 #ifdef CONFIG_VMAP_STACK
2018 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
2019 {
2020         return t->stack_vm_area;
2021 }
2022 #else
2023 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
2024 {
2025         return NULL;
2026 }
2027 #endif
2028 
2029 /* Future-safe accessor for struct task_struct's cpus_allowed. */
2030 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
2031 
2032 static inline int tsk_nr_cpus_allowed(struct task_struct *p)
2033 {
2034         return p->nr_cpus_allowed;
2035 }
2036 
2037 #define TNF_MIGRATED    0x01
2038 #define TNF_NO_GROUP    0x02
2039 #define TNF_SHARED      0x04
2040 #define TNF_FAULT_LOCAL 0x08
2041 #define TNF_MIGRATE_FAIL 0x10
2042 
2043 static inline bool in_vfork(struct task_struct *tsk)
2044 {
2045         bool ret;
2046 
2047         /*
2048          * need RCU to access ->real_parent if CLONE_VM was used along with
2049          * CLONE_PARENT.
2050          *
2051          * We check real_parent->mm == tsk->mm because CLONE_VFORK does not
2052          * imply CLONE_VM
2053          *
2054          * CLONE_VFORK can be used with CLONE_PARENT/CLONE_THREAD and thus
2055          * ->real_parent is not necessarily the task doing vfork(), so in
2056          * theory we can't rely on task_lock() if we want to dereference it.
2057          *
2058          * And in this case we can't trust the real_parent->mm == tsk->mm
2059          * check, it can be false negative. But we do not care, if init or
2060          * another oom-unkillable task does this it should blame itself.
2061          */
2062         rcu_read_lock();
2063         ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
2064         rcu_read_unlock();
2065 
2066         return ret;
2067 }
2068 
2069 #ifdef CONFIG_NUMA_BALANCING
2070 extern void task_numa_fault(int last_node, int node, int pages, int flags);
2071 extern pid_t task_numa_group_id(struct task_struct *p);
2072 extern void set_numabalancing_state(bool enabled);
2073 extern void task_numa_free(struct task_struct *p);
2074 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
2075                                         int src_nid, int dst_cpu);
2076 #else
2077 static inline void task_numa_fault(int last_node, int node, int pages,
2078                                    int flags)
2079 {
2080 }
2081 static inline pid_t task_numa_group_id(struct task_struct *p)
2082 {
2083         return 0;
2084 }
2085 static inline void set_numabalancing_state(bool enabled)
2086 {
2087 }
2088 static inline void task_numa_free(struct task_struct *p)
2089 {
2090 }
2091 static inline bool should_numa_migrate_memory(struct task_struct *p,
2092                                 struct page *page, int src_nid, int dst_cpu)
2093 {
2094         return true;
2095 }
2096 #endif
2097 
2098 static inline struct pid *task_pid(struct task_struct *task)
2099 {
2100         return task->pids[PIDTYPE_PID].pid;
2101 }
2102 
2103 static inline struct pid *task_tgid(struct task_struct *task)
2104 {
2105         return task->group_leader->pids[PIDTYPE_PID].pid;
2106 }
2107 
2108 /*
2109  * Without tasklist or rcu lock it is not safe to dereference
2110  * the result of task_pgrp/task_session even if task == current,
2111  * we can race with another thread doing sys_setsid/sys_setpgid.
2112  */
2113 static inline struct pid *task_pgrp(struct task_struct *task)
2114 {
2115         return task->group_leader->pids[PIDTYPE_PGID].pid;
2116 }
2117 
2118 static inline struct pid *task_session(struct task_struct *task)
2119 {
2120         return task->group_leader->pids[PIDTYPE_SID].pid;
2121 }
2122 
2123 struct pid_namespace;
2124 
2125 /*
2126  * the helpers to get the task's different pids as they are seen
2127  * from various namespaces
2128  *
2129  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
2130  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
2131  *                     current.
2132  * task_xid_nr_ns()  : id seen from the ns specified;
2133  *
2134  * set_task_vxid()   : assigns a virtual id to a task;
2135  *
2136  * see also pid_nr() etc in include/linux/pid.h
2137  */
2138 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
2139                         struct pid_namespace *ns);
2140 
2141 static inline pid_t task_pid_nr(struct task_struct *tsk)
2142 {
2143         return tsk->pid;
2144 }
2145 
2146 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
2147                                         struct pid_namespace *ns)
2148 {
2149         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
2150 }
2151 
2152 static inline pid_t task_pid_vnr(struct task_struct *tsk)
2153 {
2154         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
2155 }
2156 
2157 
2158 static inline pid_t task_tgid_nr(struct task_struct *tsk)
2159 {
2160         return tsk->tgid;
2161 }
2162 
2163 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
2164 
2165 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
2166 {
2167         return pid_vnr(task_tgid(tsk));
2168 }
2169 
2170 
2171 static inline int pid_alive(const struct task_struct *p);
2172 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
2173 {
2174         pid_t pid = 0;
2175 
2176         rcu_read_lock();
2177         if (pid_alive(tsk))
2178                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
2179         rcu_read_unlock();
2180 
2181         return pid;
2182 }
2183 
2184 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
2185 {
2186         return task_ppid_nr_ns(tsk, &init_pid_ns);
2187 }
2188 
2189 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
2190                                         struct pid_namespace *ns)
2191 {
2192         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
2193 }
2194 
2195 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
2196 {
2197         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
2198 }
2199 
2200 
2201 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
2202                                         struct pid_namespace *ns)
2203 {
2204         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
2205 }
2206 
2207 static inline pid_t task_session_vnr(struct task_struct *tsk)
2208 {
2209         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
2210 }
2211 
2212 /* obsolete, do not use */
2213 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
2214 {
2215         return task_pgrp_nr_ns(tsk, &init_pid_ns);
2216 }
2217 
2218 /**
2219  * pid_alive - check that a task structure is not stale
2220  * @p: Task structure to be checked.
2221  *
2222  * Test if a process is not yet dead (at most zombie state)
2223  * If pid_alive fails, then pointers within the task structure
2224  * can be stale and must not be dereferenced.
2225  *
2226  * Return: 1 if the process is alive. 0 otherwise.
2227  */
2228 static inline int pid_alive(const struct task_struct *p)
2229 {
2230         return p->pids[PIDTYPE_PID].pid != NULL;
2231 }
2232 
2233 /**
2234  * is_global_init - check if a task structure is init. Since init
2235  * is free to have sub-threads we need to check tgid.
2236  * @tsk: Task structure to be checked.
2237  *
2238  * Check if a task structure is the first user space task the kernel created.
2239  *
2240  * Return: 1 if the task structure is init. 0 otherwise.
2241  */
2242 static inline int is_global_init(struct task_struct *tsk)
2243 {
2244         return task_tgid_nr(tsk) == 1;
2245 }
2246 
2247 extern struct pid *cad_pid;
2248 
2249 extern void free_task(struct task_struct *tsk);
2250 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
2251 
2252 extern void __put_task_struct(struct task_struct *t);
2253 
2254 static inline void put_task_struct(struct task_struct *t)
2255 {
2256         if (atomic_dec_and_test(&t->usage))
2257                 __put_task_struct(t);
2258 }
2259 
2260 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
2261 struct task_struct *try_get_task_struct(struct task_struct **ptask);
2262 
2263 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
2264 extern void task_cputime(struct task_struct *t,
2265                          cputime_t *utime, cputime_t *stime);
2266 extern cputime_t task_gtime(struct task_struct *t);
2267 #else
2268 static inline void task_cputime(struct task_struct *t,
2269                                 cputime_t *utime, cputime_t *stime)
2270 {
2271         *utime = t->utime;
2272         *stime = t->stime;
2273 }
2274 
2275 static inline cputime_t task_gtime(struct task_struct *t)
2276 {
2277         return t->gtime;
2278 }
2279 #endif
2280 
2281 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
2282 static inline void task_cputime_scaled(struct task_struct *t,
2283                                        cputime_t *utimescaled,
2284                                        cputime_t *stimescaled)
2285 {
2286         *utimescaled = t->utimescaled;
2287         *stimescaled = t->stimescaled;
2288 }
2289 #else
2290 static inline void task_cputime_scaled(struct task_struct *t,
2291                                        cputime_t *utimescaled,
2292                                        cputime_t *stimescaled)
2293 {
2294         task_cputime(t, utimescaled, stimescaled);
2295 }
2296 #endif
2297 
2298 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2299 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2300 
2301 /*
2302  * Per process flags
2303  */
2304 #define PF_IDLE         0x00000002      /* I am an IDLE thread */
2305 #define PF_EXITING      0x00000004      /* getting shut down */
2306 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
2307 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
2308 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
2309 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
2310 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
2311 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
2312 #define PF_DUMPCORE     0x00000200      /* dumped core */
2313 #define PF_SIGNALED     0x00000400      /* killed by a signal */
2314 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
2315 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
2316 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
2317 #define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
2318 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
2319 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
2320 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
2321 #define PF_KSWAPD       0x00040000      /* I am kswapd */
2322 #define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
2323 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
2324 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
2325 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
2326 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
2327 #define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
2328 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
2329 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
2330 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
2331 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
2332 
2333 /*
2334  * Only the _current_ task can read/write to tsk->flags, but other
2335  * tasks can access tsk->flags in readonly mode for example
2336  * with tsk_used_math (like during threaded core dumping).
2337  * There is however an exception to this rule during ptrace
2338  * or during fork: the ptracer task is allowed to write to the
2339  * child->flags of its traced child (same goes for fork, the parent
2340  * can write to the child->flags), because we're guaranteed the
2341  * child is not running and in turn not changing child->flags
2342  * at the same time the parent does it.
2343  */
2344 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2345 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2346 #define clear_used_math() clear_stopped_child_used_math(current)
2347 #define set_used_math() set_stopped_child_used_math(current)
2348 #define conditional_stopped_child_used_math(condition, child) \
2349         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2350 #define conditional_used_math(condition) \
2351         conditional_stopped_child_used_math(condition, current)
2352 #define copy_to_stopped_child_used_math(child) \
2353         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2354 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2355 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2356 #define used_math() tsk_used_math(current)
2357 
2358 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2359  * __GFP_FS is also cleared as it implies __GFP_IO.
2360  */
2361 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2362 {
2363         if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2364                 flags &= ~(__GFP_IO | __GFP_FS);
2365         return flags;
2366 }
2367 
2368 static inline unsigned int memalloc_noio_save(void)
2369 {
2370         unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2371         current->flags |= PF_MEMALLOC_NOIO;
2372         return flags;
2373 }
2374 
2375 static inline void memalloc_noio_restore(unsigned int flags)
2376 {
2377         current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2378 }
2379 
2380 /* Per-process atomic flags. */
2381 #define PFA_NO_NEW_PRIVS 0      /* May not gain new privileges. */
2382 #define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2383 #define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2384 #define PFA_LMK_WAITING  3      /* Lowmemorykiller is waiting */
2385 
2386 
2387 #define TASK_PFA_TEST(name, func)                                       \
2388         static inline bool task_##func(struct task_struct *p)           \
2389         { return test_bit(PFA_##name, &p->atomic_flags); }
2390 #define TASK_PFA_SET(name, func)                                        \
2391         static inline void task_set_##func(struct task_struct *p)       \
2392         { set_bit(PFA_##name, &p->atomic_flags); }
2393 #define TASK_PFA_CLEAR(name, func)                                      \
2394         static inline void task_clear_##func(struct task_struct *p)     \
2395         { clear_bit(PFA_##name, &p->atomic_flags); }
2396 
2397 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2398 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2399 
2400 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2401 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2402 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2403 
2404 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2405 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2406 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2407 
2408 TASK_PFA_TEST(LMK_WAITING, lmk_waiting)
2409 TASK_PFA_SET(LMK_WAITING, lmk_waiting)
2410 
2411 /*
2412  * task->jobctl flags
2413  */
2414 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
2415 
2416 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
2417 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
2418 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
2419 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
2420 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
2421 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
2422 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
2423 
2424 #define JOBCTL_STOP_DEQUEUED    (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2425 #define JOBCTL_STOP_PENDING     (1UL << JOBCTL_STOP_PENDING_BIT)
2426 #define JOBCTL_STOP_CONSUME     (1UL << JOBCTL_STOP_CONSUME_BIT)
2427 #define JOBCTL_TRAP_STOP        (1UL << JOBCTL_TRAP_STOP_BIT)
2428 #define JOBCTL_TRAP_NOTIFY      (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2429 #define JOBCTL_TRAPPING         (1UL << JOBCTL_TRAPPING_BIT)
2430 #define JOBCTL_LISTENING        (1UL << JOBCTL_LISTENING_BIT)
2431 
2432 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2433 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2434 
2435 extern bool task_set_jobctl_pending(struct task_struct *task,
2436                                     unsigned long mask);
2437 extern void task_clear_jobctl_trapping(struct task_struct *task);
2438 extern void task_clear_jobctl_pending(struct task_struct *task,
2439                                       unsigned long mask);
2440 
2441 static inline void rcu_copy_process(struct task_struct *p)
2442 {
2443 #ifdef CONFIG_PREEMPT_RCU
2444         p->rcu_read_lock_nesting = 0;
2445         p->rcu_read_unlock_special.s = 0;
2446         p->rcu_blocked_node = NULL;
2447         INIT_LIST_HEAD(&p->rcu_node_entry);
2448 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2449 #ifdef CONFIG_TASKS_RCU
2450         p->rcu_tasks_holdout = false;
2451         INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2452         p->rcu_tasks_idle_cpu = -1;
2453 #endif /* #ifdef CONFIG_TASKS_RCU */
2454 }
2455 
2456 static inline void tsk_restore_flags(struct task_struct *task,
2457                                 unsigned long orig_flags, unsigned long flags)
2458 {
2459         task->flags &= ~flags;
2460         task->flags |= orig_flags & flags;
2461 }
2462 
2463 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2464                                      const struct cpumask *trial);
2465 extern int task_can_attach(struct task_struct *p,
2466                            const struct cpumask *cs_cpus_allowed);
2467 #ifdef CONFIG_SMP
2468 extern void do_set_cpus_allowed(struct task_struct *p,
2469                                const struct cpumask *new_mask);
2470 
2471 extern int set_cpus_allowed_ptr(struct task_struct *p,
2472                                 const struct cpumask *new_mask);
2473 #else
2474 static inline void do_set_cpus_allowed(struct task_struct *p,
2475                                       const struct cpumask *new_mask)
2476 {
2477 }
2478 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2479                                        const struct cpumask *new_mask)
2480 {
2481         if (!cpumask_test_cpu(0, new_mask))
2482                 return -EINVAL;
2483         return 0;
2484 }
2485 #endif
2486 
2487 #ifdef CONFIG_NO_HZ_COMMON
2488 void calc_load_enter_idle(void);
2489 void calc_load_exit_idle(void);
2490 #else
2491 static inline void calc_load_enter_idle(void) { }
2492 static inline void calc_load_exit_idle(void) { }
2493 #endif /* CONFIG_NO_HZ_COMMON */
2494 
2495 #ifndef cpu_relax_yield
2496 #define cpu_relax_yield() cpu_relax()
2497 #endif
2498 
2499 /*
2500  * Do not use outside of architecture code which knows its limitations.
2501  *
2502  * sched_clock() has no promise of monotonicity or bounded drift between
2503  * CPUs, use (which you should not) requires disabling IRQs.
2504  *
2505  * Please use one of the three interfaces below.
2506  */
2507 extern unsigned long long notrace sched_clock(void);
2508 /*
2509  * See the comment in kernel/sched/clock.c
2510  */
2511 extern u64 running_clock(void);
2512 extern u64 sched_clock_cpu(int cpu);
2513 
2514 
2515 extern void sched_clock_init(void);
2516 
2517 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2518 static inline void sched_clock_tick(void)
2519 {
2520 }
2521 
2522 static inline void sched_clock_idle_sleep_event(void)
2523 {
2524 }
2525 
2526 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2527 {
2528 }
2529 
2530 static inline u64 cpu_clock(int cpu)
2531 {
2532         return sched_clock();
2533 }
2534 
2535 static inline u64 local_clock(void)
2536 {
2537         return sched_clock();
2538 }
2539 #else
2540 /*
2541  * Architectures can set this to 1 if they have specified
2542  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2543  * but then during bootup it turns out that sched_clock()
2544  * is reliable after all:
2545  */
2546 extern int sched_clock_stable(void);
2547 extern void set_sched_clock_stable(void);
2548 extern void clear_sched_clock_stable(void);
2549 
2550 extern void sched_clock_tick(void);
2551 extern void sched_clock_idle_sleep_event(void);
2552 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2553 
2554 /*
2555  * As outlined in clock.c, provides a fast, high resolution, nanosecond
2556  * time source that is monotonic per cpu argument and has bounded drift
2557  * between cpus.
2558  *
2559  * ######################### BIG FAT WARNING ##########################
2560  * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
2561  * # go backwards !!                                                  #
2562  * ####################################################################
2563  */
2564 static inline u64 cpu_clock(int cpu)
2565 {
2566         return sched_clock_cpu(cpu);
2567 }
2568 
2569 static inline u64 local_clock(void)
2570 {
2571         return sched_clock_cpu(raw_smp_processor_id());
2572 }
2573 #endif
2574 
2575 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2576 /*
2577  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2578  * The reason for this explicit opt-in is not to have perf penalty with
2579  * slow sched_clocks.
2580  */
2581 extern void enable_sched_clock_irqtime(void);
2582 extern void disable_sched_clock_irqtime(void);
2583 #else
2584 static inline void enable_sched_clock_irqtime(void) {}
2585 static inline void disable_sched_clock_irqtime(void) {}
2586 #endif
2587 
2588 extern unsigned long long
2589 task_sched_runtime(struct task_struct *task);
2590 
2591 /* sched_exec is called by processes performing an exec */
2592 #ifdef CONFIG_SMP
2593 extern void sched_exec(void);
2594 #else
2595 #define sched_exec()   {}
2596 #endif
2597 
2598 extern void sched_clock_idle_sleep_event(void);
2599 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2600 
2601 #ifdef CONFIG_HOTPLUG_CPU
2602 extern void idle_task_exit(void);
2603 #else
2604 static inline void idle_task_exit(void) {}
2605 #endif
2606 
2607 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2608 extern void wake_up_nohz_cpu(int cpu);
2609 #else
2610 static inline void wake_up_nohz_cpu(int cpu) { }
2611 #endif
2612 
2613 #ifdef CONFIG_NO_HZ_FULL
2614 extern u64 scheduler_tick_max_deferment(void);
2615 #endif
2616 
2617 #ifdef CONFIG_SCHED_AUTOGROUP
2618 extern void sched_autogroup_create_attach(struct task_struct *p);
2619 extern void sched_autogroup_detach(struct task_struct *p);
2620 extern void sched_autogroup_fork(struct signal_struct *sig);
2621 extern void sched_autogroup_exit(struct signal_struct *sig);
2622 extern void sched_autogroup_exit_task(struct task_struct *p);
2623 #ifdef CONFIG_PROC_FS
2624 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2625 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2626 #endif
2627 #else
2628 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2629 static inline void sched_autogroup_detach(struct task_struct *p) { }
2630 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2631 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2632 static inline void sched_autogroup_exit_task(struct task_struct *p) { }
2633 #endif
2634 
2635 extern int yield_to(struct task_struct *p, bool preempt);
2636 extern void set_user_nice(struct task_struct *p, long nice);
2637 extern int task_prio(const struct task_struct *p);
2638 /**
2639  * task_nice - return the nice value of a given task.
2640  * @p: the task in question.
2641  *
2642  * Return: The nice value [ -20 ... 0 ... 19 ].
2643  */
2644 static inline int task_nice(const struct task_struct *p)
2645 {
2646         return PRIO_TO_NICE((p)->static_prio);
2647 }
2648 extern int can_nice(const struct task_struct *p, const int nice);
2649 extern int task_curr(const struct task_struct *p);
2650 extern int idle_cpu(int cpu);
2651 extern int sched_setscheduler(struct task_struct *, int,
2652                               const struct sched_param *);
2653 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2654                                       const struct sched_param *);
2655 extern int sched_setattr(struct task_struct *,
2656                          const struct sched_attr *);
2657 extern struct task_struct *idle_task(int cpu);
2658 /**
2659  * is_idle_task - is the specified task an idle task?
2660  * @p: the task in question.
2661  *
2662  * Return: 1 if @p is an idle task. 0 otherwise.
2663  */
2664 static inline bool is_idle_task(const struct task_struct *p)
2665 {
2666         return !!(p->flags & PF_IDLE);
2667 }
2668 extern struct task_struct *curr_task(int cpu);
2669 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
2670 
2671 void yield(void);
2672 
2673 union thread_union {
2674 #ifndef CONFIG_THREAD_INFO_IN_TASK
2675         struct thread_info thread_info;
2676 #endif
2677         unsigned long stack[THREAD_SIZE/sizeof(long)];
2678 };
2679 
2680 #ifndef __HAVE_ARCH_KSTACK_END
2681 static inline int kstack_end(void *addr)
2682 {
2683         /* Reliable end of stack detection:
2684          * Some APM bios versions misalign the stack
2685          */
2686         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2687 }
2688 #endif
2689 
2690 extern union thread_union init_thread_union;
2691 extern struct task_struct init_task;
2692 
2693 extern struct   mm_struct init_mm;
2694 
2695 extern struct pid_namespace init_pid_ns;
2696 
2697 /*
2698  * find a task by one of its numerical ids
2699  *
2700  * find_task_by_pid_ns():
2701  *      finds a task by its pid in the specified namespace
2702  * find_task_by_vpid():
2703  *      finds a task by its virtual pid
2704  *
2705  * see also find_vpid() etc in include/linux/pid.h
2706  */
2707 
2708 extern struct task_struct *find_task_by_vpid(pid_t nr);
2709 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2710                 struct pid_namespace *ns);
2711 
2712 /* per-UID process charging. */
2713 extern struct user_struct * alloc_uid(kuid_t);
2714 static inline struct user_struct *get_uid(struct user_struct *u)
2715 {
2716         atomic_inc(&u->__count);
2717         return u;
2718 }
2719 extern void free_uid(struct user_struct *);
2720 
2721 #include <asm/current.h>
2722 
2723 extern void xtime_update(unsigned long ticks);
2724 
2725 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2726 extern int wake_up_process(struct task_struct *tsk);
2727 extern void wake_up_new_task(struct task_struct *tsk);
2728 #ifdef CONFIG_SMP
2729  extern void kick_process(struct task_struct *tsk);
2730 #else
2731  static inline void kick_process(struct task_struct *tsk) { }
2732 #endif
2733 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2734 extern void sched_dead(struct task_struct *p);
2735 
2736 extern void proc_caches_init(void);
2737 extern void flush_signals(struct task_struct *);
2738 extern void ignore_signals(struct task_struct *);
2739 extern void flush_signal_handlers(struct task_struct *, int force_default);
2740 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2741 
2742 static inline int kernel_dequeue_signal(siginfo_t *info)
2743 {
2744         struct task_struct *tsk = current;
2745         siginfo_t __info;
2746         int ret;
2747 
2748         spin_lock_irq(&tsk->sighand->siglock);
2749         ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
2750         spin_unlock_irq(&tsk->sighand->siglock);
2751 
2752         return ret;
2753 }
2754 
2755 static inline void kernel_signal_stop(void)
2756 {
2757         spin_lock_irq(&current->sighand->siglock);
2758         if (current->jobctl & JOBCTL_STOP_DEQUEUED)
2759                 __set_current_state(TASK_STOPPED);
2760         spin_unlock_irq(&current->sighand->siglock);
2761 
2762         schedule();
2763 }
2764 
2765 extern void release_task(struct task_struct * p);
2766 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2767 extern int force_sigsegv(int, struct task_struct *);
2768 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2769 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2770 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2771 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2772                                 const struct cred *, u32);
2773 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2774 extern int kill_pid(struct pid *pid, int sig, int priv);
2775 extern int kill_proc_info(int, struct siginfo *, pid_t);
2776 extern __must_check bool do_notify_parent(struct task_struct *, int);
2777 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2778 extern void force_sig(int, struct task_struct *);
2779 extern int send_sig(int, struct task_struct *, int);
2780 extern int zap_other_threads(struct task_struct *p);
2781 extern struct sigqueue *sigqueue_alloc(void);
2782 extern void sigqueue_free(struct sigqueue *);
2783 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2784 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2785 
2786 #ifdef TIF_RESTORE_SIGMASK
2787 /*
2788  * Legacy restore_sigmask accessors.  These are inefficient on
2789  * SMP architectures because they require atomic operations.
2790  */
2791 
2792 /**
2793  * set_restore_sigmask() - make sure saved_sigmask processing gets done
2794  *
2795  * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
2796  * will run before returning to user mode, to process the flag.  For
2797  * all callers, TIF_SIGPENDING is already set or it's no harm to set
2798  * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
2799  * arch code will notice on return to user mode, in case those bits
2800  * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
2801  * signal code always gets run when TIF_RESTORE_SIGMASK is set.
2802  */
2803 static inline void set_restore_sigmask(void)
2804 {
2805         set_thread_flag(TIF_RESTORE_SIGMASK);
2806         WARN_ON(!test_thread_flag(TIF_SIGPENDING));
2807 }
2808 static inline void clear_restore_sigmask(void)
2809 {
2810         clear_thread_flag(TIF_RESTORE_SIGMASK);
2811 }
2812 static inline bool test_restore_sigmask(void)
2813 {
2814         return test_thread_flag(TIF_RESTORE_SIGMASK);
2815 }
2816 static inline bool test_and_clear_restore_sigmask(void)
2817 {
2818         return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
2819 }
2820 
2821 #else   /* TIF_RESTORE_SIGMASK */
2822 
2823 /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
2824 static inline void set_restore_sigmask(void)
2825 {
2826         current->restore_sigmask = true;
2827         WARN_ON(!test_thread_flag(TIF_SIGPENDING));
2828 }
2829 static inline void clear_restore_sigmask(void)
2830 {
2831         current->restore_sigmask = false;
2832 }
2833 static inline bool test_restore_sigmask(void)
2834 {
2835         return current->restore_sigmask;
2836 }
2837 static inline bool test_and_clear_restore_sigmask(void)
2838 {
2839         if (!current->restore_sigmask)
2840                 return false;
2841         current->restore_sigmask = false;
2842         return true;
2843 }
2844 #endif
2845 
2846 static inline void restore_saved_sigmask(void)
2847 {
2848         if (test_and_clear_restore_sigmask())
2849                 __set_current_blocked(&current->saved_sigmask);
2850 }
2851 
2852 static inline sigset_t *sigmask_to_save(void)
2853 {
2854         sigset_t *res = &current->blocked;
2855         if (unlikely(test_restore_sigmask()))
2856                 res = &current->saved_sigmask;
2857         return res;
2858 }
2859 
2860 static inline int kill_cad_pid(int sig, int priv)
2861 {
2862         return kill_pid(cad_pid, sig, priv);
2863 }
2864 
2865 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2866 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2867 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2868 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2869 
2870 /*
2871  * True if we are on the alternate signal stack.
2872  */
2873 static inline int on_sig_stack(unsigned long sp)
2874 {
2875         /*
2876          * If the signal stack is SS_AUTODISARM then, by construction, we
2877          * can't be on the signal stack unless user code deliberately set
2878          * SS_AUTODISARM when we were already on it.
2879          *
2880          * This improves reliability: if user state gets corrupted such that
2881          * the stack pointer points very close to the end of the signal stack,
2882          * then this check will enable the signal to be handled anyway.
2883          */
2884         if (current->sas_ss_flags & SS_AUTODISARM)
2885                 return 0;
2886 
2887 #ifdef CONFIG_STACK_GROWSUP
2888         return sp >= current->sas_ss_sp &&
2889                 sp - current->sas_ss_sp < current->sas_ss_size;
2890 #else
2891         return sp > current->sas_ss_sp &&
2892                 sp - current->sas_ss_sp <= current->sas_ss_size;
2893 #endif
2894 }
2895 
2896 static inline int sas_ss_flags(unsigned long sp)
2897 {
2898         if (!current->sas_ss_size)
2899                 return SS_DISABLE;
2900 
2901         return on_sig_stack(sp) ? SS_ONSTACK : 0;
2902 }
2903 
2904 static inline void sas_ss_reset(struct task_struct *p)
2905 {
2906         p->sas_ss_sp = 0;
2907         p->sas_ss_size = 0;
2908         p->sas_ss_flags = SS_DISABLE;
2909 }
2910 
2911 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2912 {
2913         if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2914 #ifdef CONFIG_STACK_GROWSUP
2915                 return current->sas_ss_sp;
2916 #else
2917                 return current->sas_ss_sp + current->sas_ss_size;
2918 #endif
2919         return sp;
2920 }
2921 
2922 /*
2923  * Routines for handling mm_structs
2924  */
2925 extern struct mm_struct * mm_alloc(void);
2926 
2927 /* mmdrop drops the mm and the page tables */
2928 extern void __mmdrop(struct mm_struct *);
2929 static inline void mmdrop(struct mm_struct *mm)
2930 {
2931         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2932                 __mmdrop(mm);
2933 }
2934 
2935 static inline void mmdrop_async_fn(struct work_struct *work)
2936 {
2937         struct mm_struct *mm = container_of(work, struct mm_struct, async_put_work);
2938         __mmdrop(mm);
2939 }
2940 
2941 static inline void mmdrop_async(struct mm_struct *mm)
2942 {
2943         if (unlikely(atomic_dec_and_test(&mm->mm_count))) {
2944                 INIT_WORK(&mm->async_put_work, mmdrop_async_fn);
2945                 schedule_work(&mm->async_put_work);
2946         }
2947 }
2948 
2949 static inline bool mmget_not_zero(struct mm_struct *mm)
2950 {
2951         return atomic_inc_not_zero(&mm->mm_users);
2952 }
2953 
2954 /* mmput gets rid of the mappings and all user-space */
2955 extern void mmput(struct mm_struct *);
2956 #ifdef CONFIG_MMU
2957 /* same as above but performs the slow path from the async context. Can
2958  * be called from the atomic context as well
2959  */
2960 extern void mmput_async(struct mm_struct *);
2961 #endif
2962 
2963 /* Grab a reference to a task's mm, if it is not already going away */
2964 extern struct mm_struct *get_task_mm(struct task_struct *task);
2965 /*
2966  * Grab a reference to a task's mm, if it is not already going away
2967  * and ptrace_may_access with the mode parameter passed to it
2968  * succeeds.
2969  */
2970 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2971 /* Remove the current tasks stale references to the old mm_struct */
2972 extern void mm_release(struct task_struct *, struct mm_struct *);
2973 
2974 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
2975 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2976                         struct task_struct *, unsigned long);
2977 #else
2978 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2979                         struct task_struct *);
2980 
2981 /* Architectures that haven't opted into copy_thread_tls get the tls argument
2982  * via pt_regs, so ignore the tls argument passed via C. */
2983 static inline int copy_thread_tls(
2984                 unsigned long clone_flags, unsigned long sp, unsigned long arg,
2985                 struct task_struct *p, unsigned long tls)
2986 {
2987         return copy_thread(clone_flags, sp, arg, p);
2988 }
2989 #endif
2990 extern void flush_thread(void);
2991 
2992 #ifdef CONFIG_HAVE_EXIT_THREAD
2993 extern void exit_thread(struct task_struct *tsk);
2994 #else
2995 static inline void exit_thread(struct task_struct *tsk)
2996 {
2997 }
2998 #endif
2999 
3000 extern void exit_files(struct task_struct *);
3001 extern void __cleanup_sighand(struct sighand_struct *);
3002 
3003 extern void exit_itimers(struct signal_struct *);
3004 extern void flush_itimer_signals(void);
3005 
3006 extern void do_group_exit(int);
3007 
3008 extern int do_execve(struct filename *,
3009                      const char __user * const __user *,
3010                      const char __user * const __user *);
3011 extern int do_execveat(int, struct filename *,
3012                        const char __user * const __user *,
3013                        const char __user * const __user *,
3014                        int);
3015 extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
3016 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
3017 struct task_struct *fork_idle(int);
3018 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
3019 
3020 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
3021 static inline void set_task_comm(struct task_struct *tsk, const char *from)
3022 {
3023         __set_task_comm(tsk, from, false);
3024 }
3025 extern char *get_task_comm(char *to, struct task_struct *tsk);
3026 
3027 #ifdef CONFIG_SMP
3028 void scheduler_ipi(void);
3029 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
3030 #else
3031 static inline void scheduler_ipi(void) { }
3032 static inline unsigned long wait_task_inactive(struct task_struct *p,
3033                                                long match_state)
3034 {
3035         return 1;
3036 }
3037 #endif
3038 
3039 #define tasklist_empty() \
3040         list_empty(&init_task.tasks)
3041 
3042 #define next_task(p) \
3043         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
3044 
3045 #define for_each_process(p) \
3046         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
3047 
3048 extern bool current_is_single_threaded(void);
3049 
3050 /*
3051  * Careful: do_each_thread/while_each_thread is a double loop so
3052  *          'break' will not work as expected - use goto instead.
3053  */
3054 #define do_each_thread(g, t) \
3055         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
3056 
3057 #define while_each_thread(g, t) \
3058         while ((t = next_thread(t)) != g)
3059 
3060 #define __for_each_thread(signal, t)    \
3061         list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
3062 
3063 #define for_each_thread(p, t)           \
3064         __for_each_thread((p)->signal, t)
3065 
3066 /* Careful: this is a double loop, 'break' won't work as expected. */
3067 #define for_each_process_thread(p, t)   \
3068         for_each_process(p) for_each_thread(p, t)
3069 
3070 static inline int get_nr_threads(struct task_struct *tsk)
3071 {
3072         return tsk->signal->nr_threads;
3073 }
3074 
3075 static inline bool thread_group_leader(struct task_struct *p)
3076 {
3077         return p->exit_signal >= 0;
3078 }
3079 
3080 /* Do to the insanities of de_thread it is possible for a process
3081  * to have the pid of the thread group leader without actually being
3082  * the thread group leader.  For iteration through the pids in proc
3083  * all we care about is that we have a task with the appropriate
3084  * pid, we don't actually care if we have the right task.
3085  */
3086 static inline bool has_group_leader_pid(struct task_struct *p)
3087 {
3088         return task_pid(p) == p->signal->leader_pid;
3089 }
3090 
3091 static inline
3092 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
3093 {
3094         return p1->signal == p2->signal;
3095 }
3096 
3097 static inline struct task_struct *next_thread(const struct task_struct *p)
3098 {
3099         return list_entry_rcu(p->thread_group.next,
3100                               struct task_struct, thread_group);
3101 }
3102 
3103 static inline int thread_group_empty(struct task_struct *p)
3104 {
3105         return list_empty(&p->thread_group);
3106 }
3107 
3108 #define delay_group_leader(p) \
3109                 (thread_group_leader(p) && !thread_group_empty(p))
3110 
3111 /*
3112  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
3113  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
3114  * pins the final release of task.io_context.  Also protects ->cpuset and
3115  * ->cgroup.subsys[]. And ->vfork_done.
3116  *
3117  * Nests both inside and outside of read_lock(&tasklist_lock).
3118  * It must not be nested with write_lock_irq(&tasklist_lock),
3119  * neither inside nor outside.
3120  */
3121 static inline void task_lock(struct task_struct *p)
3122 {
3123         spin_lock(&p->alloc_lock);
3124 }
3125 
3126 static inline void task_unlock(struct task_struct *p)
3127 {
3128         spin_unlock(&p->alloc_lock);
3129 }
3130 
3131 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
3132                                                         unsigned long *flags);
3133 
3134 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
3135                                                        unsigned long *flags)
3136 {
3137         struct sighand_struct *ret;
3138 
3139         ret = __lock_task_sighand(tsk, flags);
3140         (void)__cond_lock(&tsk->sighand->siglock, ret);
3141         return ret;
3142 }
3143 
3144 static inline void unlock_task_sighand(struct task_struct *tsk,
3145                                                 unsigned long *flags)
3146 {
3147         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
3148 }
3149 
3150 /**
3151  * threadgroup_change_begin - mark the beginning of changes to a threadgroup
3152  * @tsk: task causing the changes
3153  *
3154  * All operations which modify a threadgroup - a new thread joining the
3155  * group, death of a member thread (the assertion of PF_EXITING) and
3156  * exec(2) dethreading the process and replacing the leader - are wrapped
3157  * by threadgroup_change_{begin|end}().  This is to provide a place which
3158  * subsystems needing threadgroup stability can hook into for
3159  * synchronization.
3160  */
3161 static inline void threadgroup_change_begin(struct task_struct *tsk)
3162 {
3163         might_sleep();
3164         cgroup_threadgroup_change_begin(tsk);
3165 }
3166 
3167 /**
3168  * threadgroup_change_end - mark the end of changes to a threadgroup
3169  * @tsk: task causing the changes
3170  *
3171  * See threadgroup_change_begin().
3172  */
3173 static inline void threadgroup_change_end(struct task_struct *tsk)
3174 {
3175         cgroup_threadgroup_change_end(tsk);
3176 }
3177 
3178 #ifdef CONFIG_THREAD_INFO_IN_TASK
3179 
3180 static inline struct thread_info *task_thread_info(struct task_struct *task)
3181 {
3182         return &task->thread_info;
3183 }
3184 
3185 /*
3186  * When accessing the stack of a non-current task that might exit, use
3187  * try_get_task_stack() instead.  task_stack_page will return a pointer
3188  * that could get freed out from under you.
3189  */
3190 static inline void *task_stack_page(const struct task_struct *task)
3191 {
3192         return task->stack;
3193 }
3194 
3195 #define setup_thread_stack(new,old)     do { } while(0)
3196 
3197 static inline unsigned long *end_of_stack(const struct task_struct *task)
3198 {
3199         return task->stack;
3200 }
3201 
3202 #elif !defined(__HAVE_THREAD_FUNCTIONS)
3203 
3204 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
3205 #define task_stack_page(task)   ((void *)(task)->stack)
3206 
3207 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
3208 {
3209         *task_thread_info(p) = *task_thread_info(org);
3210         task_thread_info(p)->task = p;
3211 }
3212 
3213 /*
3214  * Return the address of the last usable long on the stack.
3215  *
3216  * When the stack grows down, this is just above the thread
3217  * info struct. Going any lower will corrupt the threadinfo.
3218  *
3219  * When the stack grows up, this is the highest address.
3220  * Beyond that position, we corrupt data on the next page.
3221  */
3222 static inline unsigned long *end_of_stack(struct task_struct *p)
3223 {
3224 #ifdef CONFIG_STACK_GROWSUP
3225         return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
3226 #else
3227         return (unsigned long *)(task_thread_info(p) + 1);
3228 #endif
3229 }
3230 
3231 #endif
3232 
3233 #ifdef CONFIG_THREAD_INFO_IN_TASK
3234 static inline void *try_get_task_stack(struct task_struct *tsk)
3235 {
3236         return atomic_inc_not_zero(&tsk->stack_refcount) ?
3237                 task_stack_page(tsk) : NULL;
3238 }
3239 
3240 extern void put_task_stack(struct task_struct *tsk);
3241 #else
3242 static inline void *try_get_task_stack(struct task_struct *tsk)
3243 {
3244         return task_stack_page(tsk);
3245 }
3246 
3247 static inline void put_task_stack(struct task_struct *tsk) {}
3248 #endif
3249 
3250 #define task_stack_end_corrupted(task) \
3251                 (*(end_of_stack(task)) != STACK_END_MAGIC)
3252 
3253 static inline int object_is_on_stack(void *obj)
3254 {
3255         void *stack = task_stack_page(current);
3256 
3257         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
3258 }
3259 
3260 extern void thread_stack_cache_init(void);
3261 
3262 #ifdef CONFIG_DEBUG_STACK_USAGE
3263 static inline unsigned long stack_not_used(struct task_struct *p)
3264 {
3265         unsigned long *n = end_of_stack(p);
3266 
3267         do {    /* Skip over canary */
3268 # ifdef CONFIG_STACK_GROWSUP
3269                 n--;
3270 # else
3271                 n++;
3272 # endif
3273         } while (!*n);
3274 
3275 # ifdef CONFIG_STACK_GROWSUP
3276         return (unsigned long)end_of_stack(p) - (unsigned long)n;
3277 # else
3278         return (unsigned long)n - (unsigned long)end_of_stack(p);
3279 # endif
3280 }
3281 #endif
3282 extern void set_task_stack_end_magic(struct task_struct *tsk);
3283 
3284 /* set thread flags in other task's structures
3285  * - see asm/thread_info.h for TIF_xxxx flags available
3286  */
3287 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
3288 {
3289         set_ti_thread_flag(task_thread_info(tsk), flag);
3290 }
3291 
3292 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3293 {
3294         clear_ti_thread_flag(task_thread_info(tsk), flag);
3295 }
3296 
3297 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
3298 {
3299         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
3300 }
3301 
3302 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3303 {
3304         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
3305 }
3306 
3307 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
3308 {
3309         return test_ti_thread_flag(task_thread_info(tsk), flag);
3310 }
3311 
3312 static inline void set_tsk_need_resched(struct task_struct *tsk)
3313 {
3314         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3315 }
3316 
3317 static inline void clear_tsk_need_resched(struct task_struct *tsk)
3318 {
3319         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3320 }
3321 
3322 static inline int test_tsk_need_resched(struct task_struct *tsk)
3323 {
3324         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
3325 }
3326 
3327 static inline int restart_syscall(void)
3328 {
3329         set_tsk_thread_flag(current, TIF_SIGPENDING);
3330         return -ERESTARTNOINTR;
3331 }
3332 
3333 static inline int signal_pending(struct task_struct *p)
3334 {
3335         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
3336 }
3337 
3338 static inline int __fatal_signal_pending(struct task_struct *p)
3339 {
3340         return unlikely(sigismember(&p->pending.signal, SIGKILL));
3341 }
3342 
3343 static inline int fatal_signal_pending(struct task_struct *p)
3344 {
3345         return signal_pending(p) && __fatal_signal_pending(p);
3346 }
3347 
3348 static inline int signal_pending_state(long state, struct task_struct *p)
3349 {
3350         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
3351                 return 0;
3352         if (!signal_pending(p))
3353                 return 0;
3354 
3355         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
3356 }
3357 
3358 /*
3359  * cond_resched() and cond_resched_lock(): latency reduction via
3360  * explicit rescheduling in places that are safe. The return
3361  * value indicates whether a reschedule was done in fact.
3362  * cond_resched_lock() will drop the spinlock before scheduling,
3363  * cond_resched_softirq() will enable bhs before scheduling.
3364  */
3365 #ifndef CONFIG_PREEMPT
3366 extern int _cond_resched(void);
3367 #else
3368 static inline int _cond_resched(void) { return 0; }
3369 #endif
3370 
3371 #define cond_resched() ({                       \
3372         ___might_sleep(__FILE__, __LINE__, 0);  \
3373         _cond_resched();                        \
3374 })
3375 
3376 extern int __cond_resched_lock(spinlock_t *lock);
3377 
3378 #define cond_resched_lock(lock) ({                              \
3379         ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
3380         __cond_resched_lock(lock);                              \
3381 })
3382 
3383 extern int __cond_resched_softirq(void);
3384 
3385 #define cond_resched_softirq() ({                                       \
3386         ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
3387         __cond_resched_softirq();                                       \
3388 })
3389 
3390 static inline void cond_resched_rcu(void)
3391 {
3392 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
3393         rcu_read_unlock();
3394         cond_resched();
3395         rcu_read_lock();
3396 #endif
3397 }
3398 
3399 static inline unsigned long get_preempt_disable_ip(struct task_struct *p)
3400 {
3401 #ifdef CONFIG_DEBUG_PREEMPT
3402         return p->preempt_disable_ip;
3403 #else
3404         return 0;
3405 #endif
3406 }
3407 
3408 /*
3409  * Does a critical section need to be broken due to another
3410  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
3411  * but a general need for low latency)
3412  */
3413 static inline int spin_needbreak(spinlock_t *lock)
3414 {
3415 #ifdef CONFIG_PREEMPT
3416         return spin_is_contended(lock);
3417 #else
3418         return 0;
3419 #endif
3420 }
3421 
3422 /*
3423  * Idle thread specific functions to determine the need_resched
3424  * polling state.
3425  */
3426 #ifdef TIF_POLLING_NRFLAG
3427 static inline int tsk_is_polling(struct task_struct *p)
3428 {
3429         return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
3430 }
3431 
3432 static inline void __current_set_polling(void)
3433 {
3434         set_thread_flag(TIF_POLLING_NRFLAG);
3435 }
3436 
3437 static inline bool __must_check current_set_polling_and_test(void)
3438 {
3439         __current_set_polling();
3440 
3441         /*
3442          * Polling state must be visible before we test NEED_RESCHED,
3443          * paired by resched_curr()
3444          */
3445         smp_mb__after_atomic();
3446 
3447         return unlikely(tif_need_resched());
3448 }
3449 
3450 static inline void __current_clr_polling(void)
3451 {
3452         clear_thread_flag(TIF_POLLING_NRFLAG);
3453 }
3454 
3455 static inline bool __must_check current_clr_polling_and_test(void)
3456 {
3457         __current_clr_polling();
3458 
3459         /*
3460          * Polling state must be visible before we test NEED_RESCHED,
3461          * paired by resched_curr()
3462          */
3463         smp_mb__after_atomic();
3464 
3465         return unlikely(tif_need_resched());
3466 }
3467 
3468 #else
3469 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
3470 static inline void __current_set_polling(void) { }
3471 static inline void __current_clr_polling(void) { }
3472 
3473 static inline bool __must_check current_set_polling_and_test(void)
3474 {
3475         return unlikely(tif_need_resched());
3476 }
3477 static inline bool __must_check current_clr_polling_and_test(void)
3478 {
3479         return unlikely(tif_need_resched());
3480 }
3481 #endif
3482 
3483 static inline void current_clr_polling(void)
3484 {
3485         __current_clr_polling();
3486 
3487         /*
3488          * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3489          * Once the bit is cleared, we'll get IPIs with every new
3490          * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3491          * fold.
3492          */
3493         smp_mb(); /* paired with resched_curr() */
3494 
3495         preempt_fold_need_resched();
3496 }
3497 
3498 static __always_inline bool need_resched(void)
3499 {
3500         return unlikely(tif_need_resched());
3501 }
3502 
3503 /*
3504  * Thread group CPU time accounting.
3505  */
3506 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3507 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3508 
3509 /*
3510  * Reevaluate whether the task has signals pending delivery.
3511  * Wake the task if so.
3512  * This is required every time the blocked sigset_t changes.
3513  * callers must hold sighand->siglock.
3514  */
3515 extern void recalc_sigpending_and_wake(struct task_struct *t);
3516 extern void recalc_sigpending(void);
3517 
3518 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3519 
3520 static inline void signal_wake_up(struct task_struct *t, bool resume)
3521 {
3522         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3523 }
3524 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3525 {
3526         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3527 }
3528 
3529 /*
3530  * Wrappers for p->thread_info->cpu access. No-op on UP.
3531  */
3532 #ifdef CONFIG_SMP
3533 
3534 static inline unsigned int task_cpu(const struct task_struct *p)
3535 {
3536 #ifdef CONFIG_THREAD_INFO_IN_TASK
3537         return p->cpu;
3538 #else
3539         return task_thread_info(p)->cpu;
3540 #endif
3541 }
3542 
3543 static inline int task_node(const struct task_struct *p)
3544 {
3545         return cpu_to_node(task_cpu(p));
3546 }
3547 
3548 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3549 
3550 #else
3551 
3552 static inline unsigned int task_cpu(const struct task_struct *p)
3553 {
3554         return 0;
3555 }
3556 
3557 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3558 {
3559 }
3560 
3561 #endif /* CONFIG_SMP */
3562 
3563 /*
3564  * In order to reduce various lock holder preemption latencies provide an
3565  * interface to see if a vCPU is currently running or not.
3566  *
3567  * This allows us to terminate optimistic spin loops and block, analogous to
3568  * the native optimistic spin heuristic of testing if the lock owner task is
3569  * running or not.
3570  */
3571 #ifndef vcpu_is_preempted
3572 # define vcpu_is_preempted(cpu) false
3573 #endif
3574 
3575 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3576 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3577 
3578 #ifdef CONFIG_CGROUP_SCHED
3579 extern struct task_group root_task_group;
3580 #endif /* CONFIG_CGROUP_SCHED */
3581 
3582 extern int task_can_switch_user(struct user_struct *up,
3583                                         struct task_struct *tsk);
3584 
3585 #ifdef CONFIG_TASK_XACCT
3586 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3587 {
3588         tsk->ioac.rchar += amt;
3589 }
3590 
3591 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3592 {
3593         tsk->ioac.wchar += amt;
3594 }
3595 
3596 static inline void inc_syscr(struct task_struct *tsk)
3597 {
3598         tsk->ioac.syscr++;
3599 }
3600 
3601 static inline void inc_syscw(struct task_struct *tsk)
3602 {
3603         tsk->ioac.syscw++;
3604 }
3605 #else
3606 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3607 {
3608 }
3609 
3610 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3611 {
3612 }
3613 
3614 static inline void inc_syscr(struct task_struct *tsk)
3615 {
3616 }
3617 
3618 static inline void inc_syscw(struct task_struct *tsk)
3619 {
3620 }
3621 #endif
3622 
3623 #ifndef TASK_SIZE_OF
3624 #define TASK_SIZE_OF(tsk)       TASK_SIZE
3625 #endif
3626 
3627 #ifdef CONFIG_MEMCG
3628 extern void mm_update_next_owner(struct mm_struct *mm);
3629 #else
3630 static inline void mm_update_next_owner(struct mm_struct *mm)
3631 {
3632 }
3633 #endif /* CONFIG_MEMCG */
3634 
3635 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3636                 unsigned int limit)
3637 {
3638         return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3639 }
3640 
3641 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3642                 unsigned int limit)
3643 {
3644         return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3645 }
3646 
3647 static inline unsigned long rlimit(unsigned int limit)
3648 {
3649         return task_rlimit(current, limit);
3650 }
3651 
3652 static inline unsigned long rlimit_max(unsigned int limit)
3653 {
3654         return task_rlimit_max(current, limit);
3655 }
3656 
3657 #define SCHED_CPUFREQ_RT        (1U << 0)
3658 #define SCHED_CPUFREQ_DL        (1U << 1)
3659 #define SCHED_CPUFREQ_IOWAIT    (1U << 2)
3660 
3661 #define SCHED_CPUFREQ_RT_DL     (SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL)
3662 
3663 #ifdef CONFIG_CPU_FREQ
3664 struct update_util_data {
3665        void (*func)(struct update_util_data *data, u64 time, unsigned int flags);
3666 };
3667 
3668 void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
3669                        void (*func)(struct update_util_data *data, u64 time,
3670                                     unsigned int flags));
3671 void cpufreq_remove_update_util_hook(int cpu);
3672 #endif /* CONFIG_CPU_FREQ */
3673 
3674 #endif
3675 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us