xref: /linux-6.15/include/linux/sched.h (revision 1f330c32)
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/proportions.h>
44 #include <linux/seccomp.h>
45 #include <linux/rcupdate.h>
46 #include <linux/rculist.h>
47 #include <linux/rtmutex.h>
48 
49 #include <linux/time.h>
50 #include <linux/param.h>
51 #include <linux/resource.h>
52 #include <linux/timer.h>
53 #include <linux/hrtimer.h>
54 #include <linux/task_io_accounting.h>
55 #include <linux/latencytop.h>
56 #include <linux/cred.h>
57 #include <linux/llist.h>
58 #include <linux/uidgid.h>
59 #include <linux/gfp.h>
60 #include <linux/magic.h>
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 update_cpu_load_nohz(int active);
181 #else
182 static inline void update_cpu_load_nohz(int active) { }
183 #endif
184 
185 extern unsigned long get_parent_ip(unsigned long addr);
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_STATE_MAX		2048
223 
224 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN"
225 
226 extern char ___assert_task_state[1 - 2*!!(
227 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
228 
229 /* Convenience macros for the sake of set_task_state */
230 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
231 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
232 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
233 
234 #define TASK_IDLE		(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
235 
236 /* Convenience macros for the sake of wake_up */
237 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
238 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
239 
240 /* get_task_state() */
241 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
242 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
243 				 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
244 
245 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
246 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
247 #define task_is_stopped_or_traced(task)	\
248 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
249 #define task_contributes_to_load(task)	\
250 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
251 				 (task->flags & PF_FROZEN) == 0 && \
252 				 (task->state & TASK_NOLOAD) == 0)
253 
254 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
255 
256 #define __set_task_state(tsk, state_value)			\
257 	do {							\
258 		(tsk)->task_state_change = _THIS_IP_;		\
259 		(tsk)->state = (state_value);			\
260 	} while (0)
261 #define set_task_state(tsk, state_value)			\
262 	do {							\
263 		(tsk)->task_state_change = _THIS_IP_;		\
264 		smp_store_mb((tsk)->state, (state_value));		\
265 	} while (0)
266 
267 /*
268  * set_current_state() includes a barrier so that the write of current->state
269  * is correctly serialised wrt the caller's subsequent test of whether to
270  * actually sleep:
271  *
272  *	set_current_state(TASK_UNINTERRUPTIBLE);
273  *	if (do_i_need_to_sleep())
274  *		schedule();
275  *
276  * If the caller does not need such serialisation then use __set_current_state()
277  */
278 #define __set_current_state(state_value)			\
279 	do {							\
280 		current->task_state_change = _THIS_IP_;		\
281 		current->state = (state_value);			\
282 	} while (0)
283 #define set_current_state(state_value)				\
284 	do {							\
285 		current->task_state_change = _THIS_IP_;		\
286 		smp_store_mb(current->state, (state_value));		\
287 	} while (0)
288 
289 #else
290 
291 #define __set_task_state(tsk, state_value)		\
292 	do { (tsk)->state = (state_value); } while (0)
293 #define set_task_state(tsk, state_value)		\
294 	smp_store_mb((tsk)->state, (state_value))
295 
296 /*
297  * set_current_state() includes a barrier so that the write of current->state
298  * is correctly serialised wrt the caller's subsequent test of whether to
299  * actually sleep:
300  *
301  *	set_current_state(TASK_UNINTERRUPTIBLE);
302  *	if (do_i_need_to_sleep())
303  *		schedule();
304  *
305  * If the caller does not need such serialisation then use __set_current_state()
306  */
307 #define __set_current_state(state_value)		\
308 	do { current->state = (state_value); } while (0)
309 #define set_current_state(state_value)			\
310 	smp_store_mb(current->state, (state_value))
311 
312 #endif
313 
314 /* Task command name length */
315 #define TASK_COMM_LEN 16
316 
317 #include <linux/spinlock.h>
318 
319 /*
320  * This serializes "schedule()" and also protects
321  * the run-queue from deletions/modifications (but
322  * _adding_ to the beginning of the run-queue has
323  * a separate lock).
324  */
325 extern rwlock_t tasklist_lock;
326 extern spinlock_t mmlist_lock;
327 
328 struct task_struct;
329 
330 #ifdef CONFIG_PROVE_RCU
331 extern int lockdep_tasklist_lock_is_held(void);
332 #endif /* #ifdef CONFIG_PROVE_RCU */
333 
334 extern void sched_init(void);
335 extern void sched_init_smp(void);
336 extern asmlinkage void schedule_tail(struct task_struct *prev);
337 extern void init_idle(struct task_struct *idle, int cpu);
338 extern void init_idle_bootup_task(struct task_struct *idle);
339 
340 extern cpumask_var_t cpu_isolated_map;
341 
342 extern int runqueue_is_locked(int cpu);
343 
344 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
345 extern void nohz_balance_enter_idle(int cpu);
346 extern void set_cpu_sd_state_idle(void);
347 extern int get_nohz_timer_target(void);
348 #else
349 static inline void nohz_balance_enter_idle(int cpu) { }
350 static inline void set_cpu_sd_state_idle(void) { }
351 #endif
352 
353 /*
354  * Only dump TASK_* tasks. (0 for all tasks)
355  */
356 extern void show_state_filter(unsigned long state_filter);
357 
358 static inline void show_state(void)
359 {
360 	show_state_filter(0);
361 }
362 
363 extern void show_regs(struct pt_regs *);
364 
365 /*
366  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
367  * task), SP is the stack pointer of the first frame that should be shown in the back
368  * trace (or NULL if the entire call-chain of the task should be shown).
369  */
370 extern void show_stack(struct task_struct *task, unsigned long *sp);
371 
372 extern void cpu_init (void);
373 extern void trap_init(void);
374 extern void update_process_times(int user);
375 extern void scheduler_tick(void);
376 
377 extern void sched_show_task(struct task_struct *p);
378 
379 #ifdef CONFIG_LOCKUP_DETECTOR
380 extern void touch_softlockup_watchdog_sched(void);
381 extern void touch_softlockup_watchdog(void);
382 extern void touch_softlockup_watchdog_sync(void);
383 extern void touch_all_softlockup_watchdogs(void);
384 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
385 				  void __user *buffer,
386 				  size_t *lenp, loff_t *ppos);
387 extern unsigned int  softlockup_panic;
388 extern unsigned int  hardlockup_panic;
389 void lockup_detector_init(void);
390 #else
391 static inline void touch_softlockup_watchdog_sched(void)
392 {
393 }
394 static inline void touch_softlockup_watchdog(void)
395 {
396 }
397 static inline void touch_softlockup_watchdog_sync(void)
398 {
399 }
400 static inline void touch_all_softlockup_watchdogs(void)
401 {
402 }
403 static inline void lockup_detector_init(void)
404 {
405 }
406 #endif
407 
408 #ifdef CONFIG_DETECT_HUNG_TASK
409 void reset_hung_task_detector(void);
410 #else
411 static inline void reset_hung_task_detector(void)
412 {
413 }
414 #endif
415 
416 /* Attach to any functions which should be ignored in wchan output. */
417 #define __sched		__attribute__((__section__(".sched.text")))
418 
419 /* Linker adds these: start and end of __sched functions */
420 extern char __sched_text_start[], __sched_text_end[];
421 
422 /* Is this address in the __sched functions? */
423 extern int in_sched_functions(unsigned long addr);
424 
425 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
426 extern signed long schedule_timeout(signed long timeout);
427 extern signed long schedule_timeout_interruptible(signed long timeout);
428 extern signed long schedule_timeout_killable(signed long timeout);
429 extern signed long schedule_timeout_uninterruptible(signed long timeout);
430 asmlinkage void schedule(void);
431 extern void schedule_preempt_disabled(void);
432 
433 extern long io_schedule_timeout(long timeout);
434 
435 static inline void io_schedule(void)
436 {
437 	io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
438 }
439 
440 struct nsproxy;
441 struct user_namespace;
442 
443 #ifdef CONFIG_MMU
444 extern void arch_pick_mmap_layout(struct mm_struct *mm);
445 extern unsigned long
446 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
447 		       unsigned long, unsigned long);
448 extern unsigned long
449 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
450 			  unsigned long len, unsigned long pgoff,
451 			  unsigned long flags);
452 #else
453 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
454 #endif
455 
456 #define SUID_DUMP_DISABLE	0	/* No setuid dumping */
457 #define SUID_DUMP_USER		1	/* Dump as user of process */
458 #define SUID_DUMP_ROOT		2	/* Dump as root */
459 
460 /* mm flags */
461 
462 /* for SUID_DUMP_* above */
463 #define MMF_DUMPABLE_BITS 2
464 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
465 
466 extern void set_dumpable(struct mm_struct *mm, int value);
467 /*
468  * This returns the actual value of the suid_dumpable flag. For things
469  * that are using this for checking for privilege transitions, it must
470  * test against SUID_DUMP_USER rather than treating it as a boolean
471  * value.
472  */
473 static inline int __get_dumpable(unsigned long mm_flags)
474 {
475 	return mm_flags & MMF_DUMPABLE_MASK;
476 }
477 
478 static inline int get_dumpable(struct mm_struct *mm)
479 {
480 	return __get_dumpable(mm->flags);
481 }
482 
483 /* coredump filter bits */
484 #define MMF_DUMP_ANON_PRIVATE	2
485 #define MMF_DUMP_ANON_SHARED	3
486 #define MMF_DUMP_MAPPED_PRIVATE	4
487 #define MMF_DUMP_MAPPED_SHARED	5
488 #define MMF_DUMP_ELF_HEADERS	6
489 #define MMF_DUMP_HUGETLB_PRIVATE 7
490 #define MMF_DUMP_HUGETLB_SHARED  8
491 #define MMF_DUMP_DAX_PRIVATE	9
492 #define MMF_DUMP_DAX_SHARED	10
493 
494 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
495 #define MMF_DUMP_FILTER_BITS	9
496 #define MMF_DUMP_FILTER_MASK \
497 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
498 #define MMF_DUMP_FILTER_DEFAULT \
499 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
500 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
501 
502 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
503 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
504 #else
505 # define MMF_DUMP_MASK_DEFAULT_ELF	0
506 #endif
507 					/* leave room for more dump flags */
508 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
509 #define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
510 #define MMF_EXE_FILE_CHANGED	18	/* see prctl_set_mm_exe_file() */
511 
512 #define MMF_HAS_UPROBES		19	/* has uprobes */
513 #define MMF_RECALC_UPROBES	20	/* MMF_HAS_UPROBES can be wrong */
514 
515 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
516 
517 struct sighand_struct {
518 	atomic_t		count;
519 	struct k_sigaction	action[_NSIG];
520 	spinlock_t		siglock;
521 	wait_queue_head_t	signalfd_wqh;
522 };
523 
524 struct pacct_struct {
525 	int			ac_flag;
526 	long			ac_exitcode;
527 	unsigned long		ac_mem;
528 	cputime_t		ac_utime, ac_stime;
529 	unsigned long		ac_minflt, ac_majflt;
530 };
531 
532 struct cpu_itimer {
533 	cputime_t expires;
534 	cputime_t incr;
535 	u32 error;
536 	u32 incr_error;
537 };
538 
539 /**
540  * struct prev_cputime - snaphsot of system and user cputime
541  * @utime: time spent in user mode
542  * @stime: time spent in system mode
543  * @lock: protects the above two fields
544  *
545  * Stores previous user/system time values such that we can guarantee
546  * monotonicity.
547  */
548 struct prev_cputime {
549 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
550 	cputime_t utime;
551 	cputime_t stime;
552 	raw_spinlock_t lock;
553 #endif
554 };
555 
556 static inline void prev_cputime_init(struct prev_cputime *prev)
557 {
558 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
559 	prev->utime = prev->stime = 0;
560 	raw_spin_lock_init(&prev->lock);
561 #endif
562 }
563 
564 /**
565  * struct task_cputime - collected CPU time counts
566  * @utime:		time spent in user mode, in &cputime_t units
567  * @stime:		time spent in kernel mode, in &cputime_t units
568  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
569  *
570  * This structure groups together three kinds of CPU time that are tracked for
571  * threads and thread groups.  Most things considering CPU time want to group
572  * these counts together and treat all three of them in parallel.
573  */
574 struct task_cputime {
575 	cputime_t utime;
576 	cputime_t stime;
577 	unsigned long long sum_exec_runtime;
578 };
579 
580 /* Alternate field names when used to cache expirations. */
581 #define virt_exp	utime
582 #define prof_exp	stime
583 #define sched_exp	sum_exec_runtime
584 
585 #define INIT_CPUTIME	\
586 	(struct task_cputime) {					\
587 		.utime = 0,					\
588 		.stime = 0,					\
589 		.sum_exec_runtime = 0,				\
590 	}
591 
592 /*
593  * This is the atomic variant of task_cputime, which can be used for
594  * storing and updating task_cputime statistics without locking.
595  */
596 struct task_cputime_atomic {
597 	atomic64_t utime;
598 	atomic64_t stime;
599 	atomic64_t sum_exec_runtime;
600 };
601 
602 #define INIT_CPUTIME_ATOMIC \
603 	(struct task_cputime_atomic) {				\
604 		.utime = ATOMIC64_INIT(0),			\
605 		.stime = ATOMIC64_INIT(0),			\
606 		.sum_exec_runtime = ATOMIC64_INIT(0),		\
607 	}
608 
609 #define PREEMPT_DISABLED	(PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
610 
611 /*
612  * Disable preemption until the scheduler is running -- use an unconditional
613  * value so that it also works on !PREEMPT_COUNT kernels.
614  *
615  * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
616  */
617 #define INIT_PREEMPT_COUNT	PREEMPT_OFFSET
618 
619 /*
620  * Initial preempt_count value; reflects the preempt_count schedule invariant
621  * which states that during context switches:
622  *
623  *    preempt_count() == 2*PREEMPT_DISABLE_OFFSET
624  *
625  * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
626  * Note: See finish_task_switch().
627  */
628 #define FORK_PREEMPT_COUNT	(2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
629 
630 /**
631  * struct thread_group_cputimer - thread group interval timer counts
632  * @cputime_atomic:	atomic thread group interval timers.
633  * @running:		true when there are timers running and
634  *			@cputime_atomic receives updates.
635  * @checking_timer:	true when a thread in the group is in the
636  *			process of checking for thread group timers.
637  *
638  * This structure contains the version of task_cputime, above, that is
639  * used for thread group CPU timer calculations.
640  */
641 struct thread_group_cputimer {
642 	struct task_cputime_atomic cputime_atomic;
643 	bool running;
644 	bool checking_timer;
645 };
646 
647 #include <linux/rwsem.h>
648 struct autogroup;
649 
650 /*
651  * NOTE! "signal_struct" does not have its own
652  * locking, because a shared signal_struct always
653  * implies a shared sighand_struct, so locking
654  * sighand_struct is always a proper superset of
655  * the locking of signal_struct.
656  */
657 struct signal_struct {
658 	atomic_t		sigcnt;
659 	atomic_t		live;
660 	int			nr_threads;
661 	struct list_head	thread_head;
662 
663 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
664 
665 	/* current thread group signal load-balancing target: */
666 	struct task_struct	*curr_target;
667 
668 	/* shared signal handling: */
669 	struct sigpending	shared_pending;
670 
671 	/* thread group exit support */
672 	int			group_exit_code;
673 	/* overloaded:
674 	 * - notify group_exit_task when ->count is equal to notify_count
675 	 * - everyone except group_exit_task is stopped during signal delivery
676 	 *   of fatal signals, group_exit_task processes the signal.
677 	 */
678 	int			notify_count;
679 	struct task_struct	*group_exit_task;
680 
681 	/* thread group stop support, overloads group_exit_code too */
682 	int			group_stop_count;
683 	unsigned int		flags; /* see SIGNAL_* flags below */
684 
685 	/*
686 	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
687 	 * manager, to re-parent orphan (double-forking) child processes
688 	 * to this process instead of 'init'. The service manager is
689 	 * able to receive SIGCHLD signals and is able to investigate
690 	 * the process until it calls wait(). All children of this
691 	 * process will inherit a flag if they should look for a
692 	 * child_subreaper process at exit.
693 	 */
694 	unsigned int		is_child_subreaper:1;
695 	unsigned int		has_child_subreaper:1;
696 
697 	/* POSIX.1b Interval Timers */
698 	int			posix_timer_id;
699 	struct list_head	posix_timers;
700 
701 	/* ITIMER_REAL timer for the process */
702 	struct hrtimer real_timer;
703 	struct pid *leader_pid;
704 	ktime_t it_real_incr;
705 
706 	/*
707 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
708 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
709 	 * values are defined to 0 and 1 respectively
710 	 */
711 	struct cpu_itimer it[2];
712 
713 	/*
714 	 * Thread group totals for process CPU timers.
715 	 * See thread_group_cputimer(), et al, for details.
716 	 */
717 	struct thread_group_cputimer cputimer;
718 
719 	/* Earliest-expiration cache. */
720 	struct task_cputime cputime_expires;
721 
722 	struct list_head cpu_timers[3];
723 
724 	struct pid *tty_old_pgrp;
725 
726 	/* boolean value for session group leader */
727 	int leader;
728 
729 	struct tty_struct *tty; /* NULL if no tty */
730 
731 #ifdef CONFIG_SCHED_AUTOGROUP
732 	struct autogroup *autogroup;
733 #endif
734 	/*
735 	 * Cumulative resource counters for dead threads in the group,
736 	 * and for reaped dead child processes forked by this group.
737 	 * Live threads maintain their own counters and add to these
738 	 * in __exit_signal, except for the group leader.
739 	 */
740 	seqlock_t stats_lock;
741 	cputime_t utime, stime, cutime, cstime;
742 	cputime_t gtime;
743 	cputime_t cgtime;
744 	struct prev_cputime prev_cputime;
745 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
746 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
747 	unsigned long inblock, oublock, cinblock, coublock;
748 	unsigned long maxrss, cmaxrss;
749 	struct task_io_accounting ioac;
750 
751 	/*
752 	 * Cumulative ns of schedule CPU time fo dead threads in the
753 	 * group, not including a zombie group leader, (This only differs
754 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
755 	 * other than jiffies.)
756 	 */
757 	unsigned long long sum_sched_runtime;
758 
759 	/*
760 	 * We don't bother to synchronize most readers of this at all,
761 	 * because there is no reader checking a limit that actually needs
762 	 * to get both rlim_cur and rlim_max atomically, and either one
763 	 * alone is a single word that can safely be read normally.
764 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
765 	 * protect this instead of the siglock, because they really
766 	 * have no need to disable irqs.
767 	 */
768 	struct rlimit rlim[RLIM_NLIMITS];
769 
770 #ifdef CONFIG_BSD_PROCESS_ACCT
771 	struct pacct_struct pacct;	/* per-process accounting information */
772 #endif
773 #ifdef CONFIG_TASKSTATS
774 	struct taskstats *stats;
775 #endif
776 #ifdef CONFIG_AUDIT
777 	unsigned audit_tty;
778 	unsigned audit_tty_log_passwd;
779 	struct tty_audit_buf *tty_audit_buf;
780 #endif
781 
782 	oom_flags_t oom_flags;
783 	short oom_score_adj;		/* OOM kill score adjustment */
784 	short oom_score_adj_min;	/* OOM kill score adjustment min value.
785 					 * Only settable by CAP_SYS_RESOURCE. */
786 
787 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
788 					 * credential calculations
789 					 * (notably. ptrace) */
790 };
791 
792 /*
793  * Bits in flags field of signal_struct.
794  */
795 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
796 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
797 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
798 #define SIGNAL_GROUP_COREDUMP	0x00000008 /* coredump in progress */
799 /*
800  * Pending notifications to parent.
801  */
802 #define SIGNAL_CLD_STOPPED	0x00000010
803 #define SIGNAL_CLD_CONTINUED	0x00000020
804 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
805 
806 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
807 
808 /* If true, all threads except ->group_exit_task have pending SIGKILL */
809 static inline int signal_group_exit(const struct signal_struct *sig)
810 {
811 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
812 		(sig->group_exit_task != NULL);
813 }
814 
815 /*
816  * Some day this will be a full-fledged user tracking system..
817  */
818 struct user_struct {
819 	atomic_t __count;	/* reference count */
820 	atomic_t processes;	/* How many processes does this user have? */
821 	atomic_t sigpending;	/* How many pending signals does this user have? */
822 #ifdef CONFIG_INOTIFY_USER
823 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
824 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
825 #endif
826 #ifdef CONFIG_FANOTIFY
827 	atomic_t fanotify_listeners;
828 #endif
829 #ifdef CONFIG_EPOLL
830 	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
831 #endif
832 #ifdef CONFIG_POSIX_MQUEUE
833 	/* protected by mq_lock	*/
834 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
835 #endif
836 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
837 	unsigned long unix_inflight;	/* How many files in flight in unix sockets */
838 
839 #ifdef CONFIG_KEYS
840 	struct key *uid_keyring;	/* UID specific keyring */
841 	struct key *session_keyring;	/* UID's default session keyring */
842 #endif
843 
844 	/* Hash table maintenance information */
845 	struct hlist_node uidhash_node;
846 	kuid_t uid;
847 
848 #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL)
849 	atomic_long_t locked_vm;
850 #endif
851 };
852 
853 extern int uids_sysfs_init(void);
854 
855 extern struct user_struct *find_user(kuid_t);
856 
857 extern struct user_struct root_user;
858 #define INIT_USER (&root_user)
859 
860 
861 struct backing_dev_info;
862 struct reclaim_state;
863 
864 #ifdef CONFIG_SCHED_INFO
865 struct sched_info {
866 	/* cumulative counters */
867 	unsigned long pcount;	      /* # of times run on this cpu */
868 	unsigned long long run_delay; /* time spent waiting on a runqueue */
869 
870 	/* timestamps */
871 	unsigned long long last_arrival,/* when we last ran on a cpu */
872 			   last_queued;	/* when we were last queued to run */
873 };
874 #endif /* CONFIG_SCHED_INFO */
875 
876 #ifdef CONFIG_TASK_DELAY_ACCT
877 struct task_delay_info {
878 	spinlock_t	lock;
879 	unsigned int	flags;	/* Private per-task flags */
880 
881 	/* For each stat XXX, add following, aligned appropriately
882 	 *
883 	 * struct timespec XXX_start, XXX_end;
884 	 * u64 XXX_delay;
885 	 * u32 XXX_count;
886 	 *
887 	 * Atomicity of updates to XXX_delay, XXX_count protected by
888 	 * single lock above (split into XXX_lock if contention is an issue).
889 	 */
890 
891 	/*
892 	 * XXX_count is incremented on every XXX operation, the delay
893 	 * associated with the operation is added to XXX_delay.
894 	 * XXX_delay contains the accumulated delay time in nanoseconds.
895 	 */
896 	u64 blkio_start;	/* Shared by blkio, swapin */
897 	u64 blkio_delay;	/* wait for sync block io completion */
898 	u64 swapin_delay;	/* wait for swapin block io completion */
899 	u32 blkio_count;	/* total count of the number of sync block */
900 				/* io operations performed */
901 	u32 swapin_count;	/* total count of the number of swapin block */
902 				/* io operations performed */
903 
904 	u64 freepages_start;
905 	u64 freepages_delay;	/* wait for memory reclaim */
906 	u32 freepages_count;	/* total count of memory reclaim */
907 };
908 #endif	/* CONFIG_TASK_DELAY_ACCT */
909 
910 static inline int sched_info_on(void)
911 {
912 #ifdef CONFIG_SCHEDSTATS
913 	return 1;
914 #elif defined(CONFIG_TASK_DELAY_ACCT)
915 	extern int delayacct_on;
916 	return delayacct_on;
917 #else
918 	return 0;
919 #endif
920 }
921 
922 enum cpu_idle_type {
923 	CPU_IDLE,
924 	CPU_NOT_IDLE,
925 	CPU_NEWLY_IDLE,
926 	CPU_MAX_IDLE_TYPES
927 };
928 
929 /*
930  * Increase resolution of cpu_capacity calculations
931  */
932 #define SCHED_CAPACITY_SHIFT	10
933 #define SCHED_CAPACITY_SCALE	(1L << SCHED_CAPACITY_SHIFT)
934 
935 /*
936  * Wake-queues are lists of tasks with a pending wakeup, whose
937  * callers have already marked the task as woken internally,
938  * and can thus carry on. A common use case is being able to
939  * do the wakeups once the corresponding user lock as been
940  * released.
941  *
942  * We hold reference to each task in the list across the wakeup,
943  * thus guaranteeing that the memory is still valid by the time
944  * the actual wakeups are performed in wake_up_q().
945  *
946  * One per task suffices, because there's never a need for a task to be
947  * in two wake queues simultaneously; it is forbidden to abandon a task
948  * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
949  * already in a wake queue, the wakeup will happen soon and the second
950  * waker can just skip it.
951  *
952  * The WAKE_Q macro declares and initializes the list head.
953  * wake_up_q() does NOT reinitialize the list; it's expected to be
954  * called near the end of a function, where the fact that the queue is
955  * not used again will be easy to see by inspection.
956  *
957  * Note that this can cause spurious wakeups. schedule() callers
958  * must ensure the call is done inside a loop, confirming that the
959  * wakeup condition has in fact occurred.
960  */
961 struct wake_q_node {
962 	struct wake_q_node *next;
963 };
964 
965 struct wake_q_head {
966 	struct wake_q_node *first;
967 	struct wake_q_node **lastp;
968 };
969 
970 #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
971 
972 #define WAKE_Q(name)					\
973 	struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
974 
975 extern void wake_q_add(struct wake_q_head *head,
976 		       struct task_struct *task);
977 extern void wake_up_q(struct wake_q_head *head);
978 
979 /*
980  * sched-domains (multiprocessor balancing) declarations:
981  */
982 #ifdef CONFIG_SMP
983 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
984 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
985 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
986 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
987 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
988 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
989 #define SD_SHARE_CPUCAPACITY	0x0080	/* Domain members share cpu power */
990 #define SD_SHARE_POWERDOMAIN	0x0100	/* Domain members share power domain */
991 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
992 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
993 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
994 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
995 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
996 #define SD_NUMA			0x4000	/* cross-node balancing */
997 
998 #ifdef CONFIG_SCHED_SMT
999 static inline int cpu_smt_flags(void)
1000 {
1001 	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
1002 }
1003 #endif
1004 
1005 #ifdef CONFIG_SCHED_MC
1006 static inline int cpu_core_flags(void)
1007 {
1008 	return SD_SHARE_PKG_RESOURCES;
1009 }
1010 #endif
1011 
1012 #ifdef CONFIG_NUMA
1013 static inline int cpu_numa_flags(void)
1014 {
1015 	return SD_NUMA;
1016 }
1017 #endif
1018 
1019 struct sched_domain_attr {
1020 	int relax_domain_level;
1021 };
1022 
1023 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
1024 	.relax_domain_level = -1,			\
1025 }
1026 
1027 extern int sched_domain_level_max;
1028 
1029 struct sched_group;
1030 
1031 struct sched_domain {
1032 	/* These fields must be setup */
1033 	struct sched_domain *parent;	/* top domain must be null terminated */
1034 	struct sched_domain *child;	/* bottom domain must be null terminated */
1035 	struct sched_group *groups;	/* the balancing groups of the domain */
1036 	unsigned long min_interval;	/* Minimum balance interval ms */
1037 	unsigned long max_interval;	/* Maximum balance interval ms */
1038 	unsigned int busy_factor;	/* less balancing by factor if busy */
1039 	unsigned int imbalance_pct;	/* No balance until over watermark */
1040 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
1041 	unsigned int busy_idx;
1042 	unsigned int idle_idx;
1043 	unsigned int newidle_idx;
1044 	unsigned int wake_idx;
1045 	unsigned int forkexec_idx;
1046 	unsigned int smt_gain;
1047 
1048 	int nohz_idle;			/* NOHZ IDLE status */
1049 	int flags;			/* See SD_* */
1050 	int level;
1051 
1052 	/* Runtime fields. */
1053 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
1054 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
1055 	unsigned int nr_balance_failed; /* initialise to 0 */
1056 
1057 	/* idle_balance() stats */
1058 	u64 max_newidle_lb_cost;
1059 	unsigned long next_decay_max_lb_cost;
1060 
1061 #ifdef CONFIG_SCHEDSTATS
1062 	/* load_balance() stats */
1063 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1064 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1065 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1066 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1067 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1068 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1069 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1070 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1071 
1072 	/* Active load balancing */
1073 	unsigned int alb_count;
1074 	unsigned int alb_failed;
1075 	unsigned int alb_pushed;
1076 
1077 	/* SD_BALANCE_EXEC stats */
1078 	unsigned int sbe_count;
1079 	unsigned int sbe_balanced;
1080 	unsigned int sbe_pushed;
1081 
1082 	/* SD_BALANCE_FORK stats */
1083 	unsigned int sbf_count;
1084 	unsigned int sbf_balanced;
1085 	unsigned int sbf_pushed;
1086 
1087 	/* try_to_wake_up() stats */
1088 	unsigned int ttwu_wake_remote;
1089 	unsigned int ttwu_move_affine;
1090 	unsigned int ttwu_move_balance;
1091 #endif
1092 #ifdef CONFIG_SCHED_DEBUG
1093 	char *name;
1094 #endif
1095 	union {
1096 		void *private;		/* used during construction */
1097 		struct rcu_head rcu;	/* used during destruction */
1098 	};
1099 
1100 	unsigned int span_weight;
1101 	/*
1102 	 * Span of all CPUs in this domain.
1103 	 *
1104 	 * NOTE: this field is variable length. (Allocated dynamically
1105 	 * by attaching extra space to the end of the structure,
1106 	 * depending on how many CPUs the kernel has booted up with)
1107 	 */
1108 	unsigned long span[0];
1109 };
1110 
1111 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1112 {
1113 	return to_cpumask(sd->span);
1114 }
1115 
1116 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1117 				    struct sched_domain_attr *dattr_new);
1118 
1119 /* Allocate an array of sched domains, for partition_sched_domains(). */
1120 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1121 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1122 
1123 bool cpus_share_cache(int this_cpu, int that_cpu);
1124 
1125 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1126 typedef int (*sched_domain_flags_f)(void);
1127 
1128 #define SDTL_OVERLAP	0x01
1129 
1130 struct sd_data {
1131 	struct sched_domain **__percpu sd;
1132 	struct sched_group **__percpu sg;
1133 	struct sched_group_capacity **__percpu sgc;
1134 };
1135 
1136 struct sched_domain_topology_level {
1137 	sched_domain_mask_f mask;
1138 	sched_domain_flags_f sd_flags;
1139 	int		    flags;
1140 	int		    numa_level;
1141 	struct sd_data      data;
1142 #ifdef CONFIG_SCHED_DEBUG
1143 	char                *name;
1144 #endif
1145 };
1146 
1147 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1148 extern void wake_up_if_idle(int cpu);
1149 
1150 #ifdef CONFIG_SCHED_DEBUG
1151 # define SD_INIT_NAME(type)		.name = #type
1152 #else
1153 # define SD_INIT_NAME(type)
1154 #endif
1155 
1156 #else /* CONFIG_SMP */
1157 
1158 struct sched_domain_attr;
1159 
1160 static inline void
1161 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1162 			struct sched_domain_attr *dattr_new)
1163 {
1164 }
1165 
1166 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1167 {
1168 	return true;
1169 }
1170 
1171 #endif	/* !CONFIG_SMP */
1172 
1173 
1174 struct io_context;			/* See blkdev.h */
1175 
1176 
1177 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1178 extern void prefetch_stack(struct task_struct *t);
1179 #else
1180 static inline void prefetch_stack(struct task_struct *t) { }
1181 #endif
1182 
1183 struct audit_context;		/* See audit.c */
1184 struct mempolicy;
1185 struct pipe_inode_info;
1186 struct uts_namespace;
1187 
1188 struct load_weight {
1189 	unsigned long weight;
1190 	u32 inv_weight;
1191 };
1192 
1193 /*
1194  * The load_avg/util_avg accumulates an infinite geometric series.
1195  * 1) load_avg factors frequency scaling into the amount of time that a
1196  * sched_entity is runnable on a rq into its weight. For cfs_rq, it is the
1197  * aggregated such weights of all runnable and blocked sched_entities.
1198  * 2) util_avg factors frequency and cpu scaling into the amount of time
1199  * that a sched_entity is running on a CPU, in the range [0..SCHED_LOAD_SCALE].
1200  * For cfs_rq, it is the aggregated such times of all runnable and
1201  * blocked sched_entities.
1202  * The 64 bit load_sum can:
1203  * 1) for cfs_rq, afford 4353082796 (=2^64/47742/88761) entities with
1204  * the highest weight (=88761) always runnable, we should not overflow
1205  * 2) for entity, support any load.weight always runnable
1206  */
1207 struct sched_avg {
1208 	u64 last_update_time, load_sum;
1209 	u32 util_sum, period_contrib;
1210 	unsigned long load_avg, util_avg;
1211 };
1212 
1213 #ifdef CONFIG_SCHEDSTATS
1214 struct sched_statistics {
1215 	u64			wait_start;
1216 	u64			wait_max;
1217 	u64			wait_count;
1218 	u64			wait_sum;
1219 	u64			iowait_count;
1220 	u64			iowait_sum;
1221 
1222 	u64			sleep_start;
1223 	u64			sleep_max;
1224 	s64			sum_sleep_runtime;
1225 
1226 	u64			block_start;
1227 	u64			block_max;
1228 	u64			exec_max;
1229 	u64			slice_max;
1230 
1231 	u64			nr_migrations_cold;
1232 	u64			nr_failed_migrations_affine;
1233 	u64			nr_failed_migrations_running;
1234 	u64			nr_failed_migrations_hot;
1235 	u64			nr_forced_migrations;
1236 
1237 	u64			nr_wakeups;
1238 	u64			nr_wakeups_sync;
1239 	u64			nr_wakeups_migrate;
1240 	u64			nr_wakeups_local;
1241 	u64			nr_wakeups_remote;
1242 	u64			nr_wakeups_affine;
1243 	u64			nr_wakeups_affine_attempts;
1244 	u64			nr_wakeups_passive;
1245 	u64			nr_wakeups_idle;
1246 };
1247 #endif
1248 
1249 struct sched_entity {
1250 	struct load_weight	load;		/* for load-balancing */
1251 	struct rb_node		run_node;
1252 	struct list_head	group_node;
1253 	unsigned int		on_rq;
1254 
1255 	u64			exec_start;
1256 	u64			sum_exec_runtime;
1257 	u64			vruntime;
1258 	u64			prev_sum_exec_runtime;
1259 
1260 	u64			nr_migrations;
1261 
1262 #ifdef CONFIG_SCHEDSTATS
1263 	struct sched_statistics statistics;
1264 #endif
1265 
1266 #ifdef CONFIG_FAIR_GROUP_SCHED
1267 	int			depth;
1268 	struct sched_entity	*parent;
1269 	/* rq on which this entity is (to be) queued: */
1270 	struct cfs_rq		*cfs_rq;
1271 	/* rq "owned" by this entity/group: */
1272 	struct cfs_rq		*my_q;
1273 #endif
1274 
1275 #ifdef CONFIG_SMP
1276 	/*
1277 	 * Per entity load average tracking.
1278 	 *
1279 	 * Put into separate cache line so it does not
1280 	 * collide with read-mostly values above.
1281 	 */
1282 	struct sched_avg	avg ____cacheline_aligned_in_smp;
1283 #endif
1284 };
1285 
1286 struct sched_rt_entity {
1287 	struct list_head run_list;
1288 	unsigned long timeout;
1289 	unsigned long watchdog_stamp;
1290 	unsigned int time_slice;
1291 
1292 	struct sched_rt_entity *back;
1293 #ifdef CONFIG_RT_GROUP_SCHED
1294 	struct sched_rt_entity	*parent;
1295 	/* rq on which this entity is (to be) queued: */
1296 	struct rt_rq		*rt_rq;
1297 	/* rq "owned" by this entity/group: */
1298 	struct rt_rq		*my_q;
1299 #endif
1300 };
1301 
1302 struct sched_dl_entity {
1303 	struct rb_node	rb_node;
1304 
1305 	/*
1306 	 * Original scheduling parameters. Copied here from sched_attr
1307 	 * during sched_setattr(), they will remain the same until
1308 	 * the next sched_setattr().
1309 	 */
1310 	u64 dl_runtime;		/* maximum runtime for each instance	*/
1311 	u64 dl_deadline;	/* relative deadline of each instance	*/
1312 	u64 dl_period;		/* separation of two instances (period) */
1313 	u64 dl_bw;		/* dl_runtime / dl_deadline		*/
1314 
1315 	/*
1316 	 * Actual scheduling parameters. Initialized with the values above,
1317 	 * they are continously updated during task execution. Note that
1318 	 * the remaining runtime could be < 0 in case we are in overrun.
1319 	 */
1320 	s64 runtime;		/* remaining runtime for this instance	*/
1321 	u64 deadline;		/* absolute deadline for this instance	*/
1322 	unsigned int flags;	/* specifying the scheduler behaviour	*/
1323 
1324 	/*
1325 	 * Some bool flags:
1326 	 *
1327 	 * @dl_throttled tells if we exhausted the runtime. If so, the
1328 	 * task has to wait for a replenishment to be performed at the
1329 	 * next firing of dl_timer.
1330 	 *
1331 	 * @dl_new tells if a new instance arrived. If so we must
1332 	 * start executing it with full runtime and reset its absolute
1333 	 * deadline;
1334 	 *
1335 	 * @dl_boosted tells if we are boosted due to DI. If so we are
1336 	 * outside bandwidth enforcement mechanism (but only until we
1337 	 * exit the critical section);
1338 	 *
1339 	 * @dl_yielded tells if task gave up the cpu before consuming
1340 	 * all its available runtime during the last job.
1341 	 */
1342 	int dl_throttled, dl_new, dl_boosted, dl_yielded;
1343 
1344 	/*
1345 	 * Bandwidth enforcement timer. Each -deadline task has its
1346 	 * own bandwidth to be enforced, thus we need one timer per task.
1347 	 */
1348 	struct hrtimer dl_timer;
1349 };
1350 
1351 union rcu_special {
1352 	struct {
1353 		u8 blocked;
1354 		u8 need_qs;
1355 		u8 exp_need_qs;
1356 		u8 pad;	/* Otherwise the compiler can store garbage here. */
1357 	} b; /* Bits. */
1358 	u32 s; /* Set of bits. */
1359 };
1360 struct rcu_node;
1361 
1362 enum perf_event_task_context {
1363 	perf_invalid_context = -1,
1364 	perf_hw_context = 0,
1365 	perf_sw_context,
1366 	perf_nr_task_contexts,
1367 };
1368 
1369 /* Track pages that require TLB flushes */
1370 struct tlbflush_unmap_batch {
1371 	/*
1372 	 * Each bit set is a CPU that potentially has a TLB entry for one of
1373 	 * the PFNs being flushed. See set_tlb_ubc_flush_pending().
1374 	 */
1375 	struct cpumask cpumask;
1376 
1377 	/* True if any bit in cpumask is set */
1378 	bool flush_required;
1379 
1380 	/*
1381 	 * If true then the PTE was dirty when unmapped. The entry must be
1382 	 * flushed before IO is initiated or a stale TLB entry potentially
1383 	 * allows an update without redirtying the page.
1384 	 */
1385 	bool writable;
1386 };
1387 
1388 struct task_struct {
1389 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1390 	void *stack;
1391 	atomic_t usage;
1392 	unsigned int flags;	/* per process flags, defined below */
1393 	unsigned int ptrace;
1394 
1395 #ifdef CONFIG_SMP
1396 	struct llist_node wake_entry;
1397 	int on_cpu;
1398 	unsigned int wakee_flips;
1399 	unsigned long wakee_flip_decay_ts;
1400 	struct task_struct *last_wakee;
1401 
1402 	int wake_cpu;
1403 #endif
1404 	int on_rq;
1405 
1406 	int prio, static_prio, normal_prio;
1407 	unsigned int rt_priority;
1408 	const struct sched_class *sched_class;
1409 	struct sched_entity se;
1410 	struct sched_rt_entity rt;
1411 #ifdef CONFIG_CGROUP_SCHED
1412 	struct task_group *sched_task_group;
1413 #endif
1414 	struct sched_dl_entity dl;
1415 
1416 #ifdef CONFIG_PREEMPT_NOTIFIERS
1417 	/* list of struct preempt_notifier: */
1418 	struct hlist_head preempt_notifiers;
1419 #endif
1420 
1421 #ifdef CONFIG_BLK_DEV_IO_TRACE
1422 	unsigned int btrace_seq;
1423 #endif
1424 
1425 	unsigned int policy;
1426 	int nr_cpus_allowed;
1427 	cpumask_t cpus_allowed;
1428 
1429 #ifdef CONFIG_PREEMPT_RCU
1430 	int rcu_read_lock_nesting;
1431 	union rcu_special rcu_read_unlock_special;
1432 	struct list_head rcu_node_entry;
1433 	struct rcu_node *rcu_blocked_node;
1434 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1435 #ifdef CONFIG_TASKS_RCU
1436 	unsigned long rcu_tasks_nvcsw;
1437 	bool rcu_tasks_holdout;
1438 	struct list_head rcu_tasks_holdout_list;
1439 	int rcu_tasks_idle_cpu;
1440 #endif /* #ifdef CONFIG_TASKS_RCU */
1441 
1442 #ifdef CONFIG_SCHED_INFO
1443 	struct sched_info sched_info;
1444 #endif
1445 
1446 	struct list_head tasks;
1447 #ifdef CONFIG_SMP
1448 	struct plist_node pushable_tasks;
1449 	struct rb_node pushable_dl_tasks;
1450 #endif
1451 
1452 	struct mm_struct *mm, *active_mm;
1453 	/* per-thread vma caching */
1454 	u32 vmacache_seqnum;
1455 	struct vm_area_struct *vmacache[VMACACHE_SIZE];
1456 #if defined(SPLIT_RSS_COUNTING)
1457 	struct task_rss_stat	rss_stat;
1458 #endif
1459 /* task state */
1460 	int exit_state;
1461 	int exit_code, exit_signal;
1462 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1463 	unsigned long jobctl;	/* JOBCTL_*, siglock protected */
1464 
1465 	/* Used for emulating ABI behavior of previous Linux versions */
1466 	unsigned int personality;
1467 
1468 	/* scheduler bits, serialized by scheduler locks */
1469 	unsigned sched_reset_on_fork:1;
1470 	unsigned sched_contributes_to_load:1;
1471 	unsigned sched_migrated:1;
1472 	unsigned :0; /* force alignment to the next boundary */
1473 
1474 	/* unserialized, strictly 'current' */
1475 	unsigned in_execve:1; /* bit to tell LSMs we're in execve */
1476 	unsigned in_iowait:1;
1477 #ifdef CONFIG_MEMCG
1478 	unsigned memcg_may_oom:1;
1479 #endif
1480 #ifdef CONFIG_MEMCG_KMEM
1481 	unsigned memcg_kmem_skip_account:1;
1482 #endif
1483 #ifdef CONFIG_COMPAT_BRK
1484 	unsigned brk_randomized:1;
1485 #endif
1486 
1487 	unsigned long atomic_flags; /* Flags needing atomic access. */
1488 
1489 	struct restart_block restart_block;
1490 
1491 	pid_t pid;
1492 	pid_t tgid;
1493 
1494 #ifdef CONFIG_CC_STACKPROTECTOR
1495 	/* Canary value for the -fstack-protector gcc feature */
1496 	unsigned long stack_canary;
1497 #endif
1498 	/*
1499 	 * pointers to (original) parent process, youngest child, younger sibling,
1500 	 * older sibling, respectively.  (p->father can be replaced with
1501 	 * p->real_parent->pid)
1502 	 */
1503 	struct task_struct __rcu *real_parent; /* real parent process */
1504 	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1505 	/*
1506 	 * children/sibling forms the list of my natural children
1507 	 */
1508 	struct list_head children;	/* list of my children */
1509 	struct list_head sibling;	/* linkage in my parent's children list */
1510 	struct task_struct *group_leader;	/* threadgroup leader */
1511 
1512 	/*
1513 	 * ptraced is the list of tasks this task is using ptrace on.
1514 	 * This includes both natural children and PTRACE_ATTACH targets.
1515 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1516 	 */
1517 	struct list_head ptraced;
1518 	struct list_head ptrace_entry;
1519 
1520 	/* PID/PID hash table linkage. */
1521 	struct pid_link pids[PIDTYPE_MAX];
1522 	struct list_head thread_group;
1523 	struct list_head thread_node;
1524 
1525 	struct completion *vfork_done;		/* for vfork() */
1526 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1527 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1528 
1529 	cputime_t utime, stime, utimescaled, stimescaled;
1530 	cputime_t gtime;
1531 	struct prev_cputime prev_cputime;
1532 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1533 	seqcount_t vtime_seqcount;
1534 	unsigned long long vtime_snap;
1535 	enum {
1536 		/* Task is sleeping or running in a CPU with VTIME inactive */
1537 		VTIME_INACTIVE = 0,
1538 		/* Task runs in userspace in a CPU with VTIME active */
1539 		VTIME_USER,
1540 		/* Task runs in kernelspace in a CPU with VTIME active */
1541 		VTIME_SYS,
1542 	} vtime_snap_whence;
1543 #endif
1544 	unsigned long nvcsw, nivcsw; /* context switch counts */
1545 	u64 start_time;		/* monotonic time in nsec */
1546 	u64 real_start_time;	/* boot based time in nsec */
1547 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1548 	unsigned long min_flt, maj_flt;
1549 
1550 	struct task_cputime cputime_expires;
1551 	struct list_head cpu_timers[3];
1552 
1553 /* process credentials */
1554 	const struct cred __rcu *real_cred; /* objective and real subjective task
1555 					 * credentials (COW) */
1556 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1557 					 * credentials (COW) */
1558 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1559 				     - access with [gs]et_task_comm (which lock
1560 				       it with task_lock())
1561 				     - initialized normally by setup_new_exec */
1562 /* file system info */
1563 	struct nameidata *nameidata;
1564 #ifdef CONFIG_SYSVIPC
1565 /* ipc stuff */
1566 	struct sysv_sem sysvsem;
1567 	struct sysv_shm sysvshm;
1568 #endif
1569 #ifdef CONFIG_DETECT_HUNG_TASK
1570 /* hung task detection */
1571 	unsigned long last_switch_count;
1572 #endif
1573 /* filesystem information */
1574 	struct fs_struct *fs;
1575 /* open file information */
1576 	struct files_struct *files;
1577 /* namespaces */
1578 	struct nsproxy *nsproxy;
1579 /* signal handlers */
1580 	struct signal_struct *signal;
1581 	struct sighand_struct *sighand;
1582 
1583 	sigset_t blocked, real_blocked;
1584 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1585 	struct sigpending pending;
1586 
1587 	unsigned long sas_ss_sp;
1588 	size_t sas_ss_size;
1589 
1590 	struct callback_head *task_works;
1591 
1592 	struct audit_context *audit_context;
1593 #ifdef CONFIG_AUDITSYSCALL
1594 	kuid_t loginuid;
1595 	unsigned int sessionid;
1596 #endif
1597 	struct seccomp seccomp;
1598 
1599 /* Thread group tracking */
1600    	u32 parent_exec_id;
1601    	u32 self_exec_id;
1602 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1603  * mempolicy */
1604 	spinlock_t alloc_lock;
1605 
1606 	/* Protection of the PI data structures: */
1607 	raw_spinlock_t pi_lock;
1608 
1609 	struct wake_q_node wake_q;
1610 
1611 #ifdef CONFIG_RT_MUTEXES
1612 	/* PI waiters blocked on a rt_mutex held by this task */
1613 	struct rb_root pi_waiters;
1614 	struct rb_node *pi_waiters_leftmost;
1615 	/* Deadlock detection and priority inheritance handling */
1616 	struct rt_mutex_waiter *pi_blocked_on;
1617 #endif
1618 
1619 #ifdef CONFIG_DEBUG_MUTEXES
1620 	/* mutex deadlock detection */
1621 	struct mutex_waiter *blocked_on;
1622 #endif
1623 #ifdef CONFIG_TRACE_IRQFLAGS
1624 	unsigned int irq_events;
1625 	unsigned long hardirq_enable_ip;
1626 	unsigned long hardirq_disable_ip;
1627 	unsigned int hardirq_enable_event;
1628 	unsigned int hardirq_disable_event;
1629 	int hardirqs_enabled;
1630 	int hardirq_context;
1631 	unsigned long softirq_disable_ip;
1632 	unsigned long softirq_enable_ip;
1633 	unsigned int softirq_disable_event;
1634 	unsigned int softirq_enable_event;
1635 	int softirqs_enabled;
1636 	int softirq_context;
1637 #endif
1638 #ifdef CONFIG_LOCKDEP
1639 # define MAX_LOCK_DEPTH 48UL
1640 	u64 curr_chain_key;
1641 	int lockdep_depth;
1642 	unsigned int lockdep_recursion;
1643 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1644 	gfp_t lockdep_reclaim_gfp;
1645 #endif
1646 
1647 /* journalling filesystem info */
1648 	void *journal_info;
1649 
1650 /* stacked block device info */
1651 	struct bio_list *bio_list;
1652 
1653 #ifdef CONFIG_BLOCK
1654 /* stack plugging */
1655 	struct blk_plug *plug;
1656 #endif
1657 
1658 /* VM state */
1659 	struct reclaim_state *reclaim_state;
1660 
1661 	struct backing_dev_info *backing_dev_info;
1662 
1663 	struct io_context *io_context;
1664 
1665 	unsigned long ptrace_message;
1666 	siginfo_t *last_siginfo; /* For ptrace use.  */
1667 	struct task_io_accounting ioac;
1668 #if defined(CONFIG_TASK_XACCT)
1669 	u64 acct_rss_mem1;	/* accumulated rss usage */
1670 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1671 	cputime_t acct_timexpd;	/* stime + utime since last update */
1672 #endif
1673 #ifdef CONFIG_CPUSETS
1674 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1675 	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1676 	int cpuset_mem_spread_rotor;
1677 	int cpuset_slab_spread_rotor;
1678 #endif
1679 #ifdef CONFIG_CGROUPS
1680 	/* Control Group info protected by css_set_lock */
1681 	struct css_set __rcu *cgroups;
1682 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1683 	struct list_head cg_list;
1684 #endif
1685 #ifdef CONFIG_FUTEX
1686 	struct robust_list_head __user *robust_list;
1687 #ifdef CONFIG_COMPAT
1688 	struct compat_robust_list_head __user *compat_robust_list;
1689 #endif
1690 	struct list_head pi_state_list;
1691 	struct futex_pi_state *pi_state_cache;
1692 #endif
1693 #ifdef CONFIG_PERF_EVENTS
1694 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1695 	struct mutex perf_event_mutex;
1696 	struct list_head perf_event_list;
1697 #endif
1698 #ifdef CONFIG_DEBUG_PREEMPT
1699 	unsigned long preempt_disable_ip;
1700 #endif
1701 #ifdef CONFIG_NUMA
1702 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1703 	short il_next;
1704 	short pref_node_fork;
1705 #endif
1706 #ifdef CONFIG_NUMA_BALANCING
1707 	int numa_scan_seq;
1708 	unsigned int numa_scan_period;
1709 	unsigned int numa_scan_period_max;
1710 	int numa_preferred_nid;
1711 	unsigned long numa_migrate_retry;
1712 	u64 node_stamp;			/* migration stamp  */
1713 	u64 last_task_numa_placement;
1714 	u64 last_sum_exec_runtime;
1715 	struct callback_head numa_work;
1716 
1717 	struct list_head numa_entry;
1718 	struct numa_group *numa_group;
1719 
1720 	/*
1721 	 * numa_faults is an array split into four regions:
1722 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1723 	 * in this precise order.
1724 	 *
1725 	 * faults_memory: Exponential decaying average of faults on a per-node
1726 	 * basis. Scheduling placement decisions are made based on these
1727 	 * counts. The values remain static for the duration of a PTE scan.
1728 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1729 	 * hinting fault was incurred.
1730 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1731 	 * during the current scan window. When the scan completes, the counts
1732 	 * in faults_memory and faults_cpu decay and these values are copied.
1733 	 */
1734 	unsigned long *numa_faults;
1735 	unsigned long total_numa_faults;
1736 
1737 	/*
1738 	 * numa_faults_locality tracks if faults recorded during the last
1739 	 * scan window were remote/local or failed to migrate. The task scan
1740 	 * period is adapted based on the locality of the faults with different
1741 	 * weights depending on whether they were shared or private faults
1742 	 */
1743 	unsigned long numa_faults_locality[3];
1744 
1745 	unsigned long numa_pages_migrated;
1746 #endif /* CONFIG_NUMA_BALANCING */
1747 
1748 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1749 	struct tlbflush_unmap_batch tlb_ubc;
1750 #endif
1751 
1752 	struct rcu_head rcu;
1753 
1754 	/*
1755 	 * cache last used pipe for splice
1756 	 */
1757 	struct pipe_inode_info *splice_pipe;
1758 
1759 	struct page_frag task_frag;
1760 
1761 #ifdef	CONFIG_TASK_DELAY_ACCT
1762 	struct task_delay_info *delays;
1763 #endif
1764 #ifdef CONFIG_FAULT_INJECTION
1765 	int make_it_fail;
1766 #endif
1767 	/*
1768 	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1769 	 * balance_dirty_pages() for some dirty throttling pause
1770 	 */
1771 	int nr_dirtied;
1772 	int nr_dirtied_pause;
1773 	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1774 
1775 #ifdef CONFIG_LATENCYTOP
1776 	int latency_record_count;
1777 	struct latency_record latency_record[LT_SAVECOUNT];
1778 #endif
1779 	/*
1780 	 * time slack values; these are used to round up poll() and
1781 	 * select() etc timeout values. These are in nanoseconds.
1782 	 */
1783 	unsigned long timer_slack_ns;
1784 	unsigned long default_timer_slack_ns;
1785 
1786 #ifdef CONFIG_KASAN
1787 	unsigned int kasan_depth;
1788 #endif
1789 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1790 	/* Index of current stored address in ret_stack */
1791 	int curr_ret_stack;
1792 	/* Stack of return addresses for return function tracing */
1793 	struct ftrace_ret_stack	*ret_stack;
1794 	/* time stamp for last schedule */
1795 	unsigned long long ftrace_timestamp;
1796 	/*
1797 	 * Number of functions that haven't been traced
1798 	 * because of depth overrun.
1799 	 */
1800 	atomic_t trace_overrun;
1801 	/* Pause for the tracing */
1802 	atomic_t tracing_graph_pause;
1803 #endif
1804 #ifdef CONFIG_TRACING
1805 	/* state flags for use by tracers */
1806 	unsigned long trace;
1807 	/* bitmask and counter of trace recursion */
1808 	unsigned long trace_recursion;
1809 #endif /* CONFIG_TRACING */
1810 #ifdef CONFIG_MEMCG
1811 	struct mem_cgroup *memcg_in_oom;
1812 	gfp_t memcg_oom_gfp_mask;
1813 	int memcg_oom_order;
1814 
1815 	/* number of pages to reclaim on returning to userland */
1816 	unsigned int memcg_nr_pages_over_high;
1817 #endif
1818 #ifdef CONFIG_UPROBES
1819 	struct uprobe_task *utask;
1820 #endif
1821 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1822 	unsigned int	sequential_io;
1823 	unsigned int	sequential_io_avg;
1824 #endif
1825 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1826 	unsigned long	task_state_change;
1827 #endif
1828 	int pagefault_disabled;
1829 /* CPU-specific state of this task */
1830 	struct thread_struct thread;
1831 /*
1832  * WARNING: on x86, 'thread_struct' contains a variable-sized
1833  * structure.  It *MUST* be at the end of 'task_struct'.
1834  *
1835  * Do not put anything below here!
1836  */
1837 };
1838 
1839 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
1840 extern int arch_task_struct_size __read_mostly;
1841 #else
1842 # define arch_task_struct_size (sizeof(struct task_struct))
1843 #endif
1844 
1845 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1846 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1847 
1848 #define TNF_MIGRATED	0x01
1849 #define TNF_NO_GROUP	0x02
1850 #define TNF_SHARED	0x04
1851 #define TNF_FAULT_LOCAL	0x08
1852 #define TNF_MIGRATE_FAIL 0x10
1853 
1854 #ifdef CONFIG_NUMA_BALANCING
1855 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1856 extern pid_t task_numa_group_id(struct task_struct *p);
1857 extern void set_numabalancing_state(bool enabled);
1858 extern void task_numa_free(struct task_struct *p);
1859 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1860 					int src_nid, int dst_cpu);
1861 #else
1862 static inline void task_numa_fault(int last_node, int node, int pages,
1863 				   int flags)
1864 {
1865 }
1866 static inline pid_t task_numa_group_id(struct task_struct *p)
1867 {
1868 	return 0;
1869 }
1870 static inline void set_numabalancing_state(bool enabled)
1871 {
1872 }
1873 static inline void task_numa_free(struct task_struct *p)
1874 {
1875 }
1876 static inline bool should_numa_migrate_memory(struct task_struct *p,
1877 				struct page *page, int src_nid, int dst_cpu)
1878 {
1879 	return true;
1880 }
1881 #endif
1882 
1883 static inline struct pid *task_pid(struct task_struct *task)
1884 {
1885 	return task->pids[PIDTYPE_PID].pid;
1886 }
1887 
1888 static inline struct pid *task_tgid(struct task_struct *task)
1889 {
1890 	return task->group_leader->pids[PIDTYPE_PID].pid;
1891 }
1892 
1893 /*
1894  * Without tasklist or rcu lock it is not safe to dereference
1895  * the result of task_pgrp/task_session even if task == current,
1896  * we can race with another thread doing sys_setsid/sys_setpgid.
1897  */
1898 static inline struct pid *task_pgrp(struct task_struct *task)
1899 {
1900 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1901 }
1902 
1903 static inline struct pid *task_session(struct task_struct *task)
1904 {
1905 	return task->group_leader->pids[PIDTYPE_SID].pid;
1906 }
1907 
1908 struct pid_namespace;
1909 
1910 /*
1911  * the helpers to get the task's different pids as they are seen
1912  * from various namespaces
1913  *
1914  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1915  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1916  *                     current.
1917  * task_xid_nr_ns()  : id seen from the ns specified;
1918  *
1919  * set_task_vxid()   : assigns a virtual id to a task;
1920  *
1921  * see also pid_nr() etc in include/linux/pid.h
1922  */
1923 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1924 			struct pid_namespace *ns);
1925 
1926 static inline pid_t task_pid_nr(struct task_struct *tsk)
1927 {
1928 	return tsk->pid;
1929 }
1930 
1931 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1932 					struct pid_namespace *ns)
1933 {
1934 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1935 }
1936 
1937 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1938 {
1939 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1940 }
1941 
1942 
1943 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1944 {
1945 	return tsk->tgid;
1946 }
1947 
1948 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1949 
1950 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1951 {
1952 	return pid_vnr(task_tgid(tsk));
1953 }
1954 
1955 
1956 static inline int pid_alive(const struct task_struct *p);
1957 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1958 {
1959 	pid_t pid = 0;
1960 
1961 	rcu_read_lock();
1962 	if (pid_alive(tsk))
1963 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1964 	rcu_read_unlock();
1965 
1966 	return pid;
1967 }
1968 
1969 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1970 {
1971 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1972 }
1973 
1974 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1975 					struct pid_namespace *ns)
1976 {
1977 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1978 }
1979 
1980 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1981 {
1982 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1983 }
1984 
1985 
1986 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1987 					struct pid_namespace *ns)
1988 {
1989 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1990 }
1991 
1992 static inline pid_t task_session_vnr(struct task_struct *tsk)
1993 {
1994 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1995 }
1996 
1997 /* obsolete, do not use */
1998 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1999 {
2000 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
2001 }
2002 
2003 /**
2004  * pid_alive - check that a task structure is not stale
2005  * @p: Task structure to be checked.
2006  *
2007  * Test if a process is not yet dead (at most zombie state)
2008  * If pid_alive fails, then pointers within the task structure
2009  * can be stale and must not be dereferenced.
2010  *
2011  * Return: 1 if the process is alive. 0 otherwise.
2012  */
2013 static inline int pid_alive(const struct task_struct *p)
2014 {
2015 	return p->pids[PIDTYPE_PID].pid != NULL;
2016 }
2017 
2018 /**
2019  * is_global_init - check if a task structure is init. Since init
2020  * is free to have sub-threads we need to check tgid.
2021  * @tsk: Task structure to be checked.
2022  *
2023  * Check if a task structure is the first user space task the kernel created.
2024  *
2025  * Return: 1 if the task structure is init. 0 otherwise.
2026  */
2027 static inline int is_global_init(struct task_struct *tsk)
2028 {
2029 	return task_tgid_nr(tsk) == 1;
2030 }
2031 
2032 extern struct pid *cad_pid;
2033 
2034 extern void free_task(struct task_struct *tsk);
2035 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
2036 
2037 extern void __put_task_struct(struct task_struct *t);
2038 
2039 static inline void put_task_struct(struct task_struct *t)
2040 {
2041 	if (atomic_dec_and_test(&t->usage))
2042 		__put_task_struct(t);
2043 }
2044 
2045 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
2046 extern void task_cputime(struct task_struct *t,
2047 			 cputime_t *utime, cputime_t *stime);
2048 extern void task_cputime_scaled(struct task_struct *t,
2049 				cputime_t *utimescaled, cputime_t *stimescaled);
2050 extern cputime_t task_gtime(struct task_struct *t);
2051 #else
2052 static inline void task_cputime(struct task_struct *t,
2053 				cputime_t *utime, cputime_t *stime)
2054 {
2055 	if (utime)
2056 		*utime = t->utime;
2057 	if (stime)
2058 		*stime = t->stime;
2059 }
2060 
2061 static inline void task_cputime_scaled(struct task_struct *t,
2062 				       cputime_t *utimescaled,
2063 				       cputime_t *stimescaled)
2064 {
2065 	if (utimescaled)
2066 		*utimescaled = t->utimescaled;
2067 	if (stimescaled)
2068 		*stimescaled = t->stimescaled;
2069 }
2070 
2071 static inline cputime_t task_gtime(struct task_struct *t)
2072 {
2073 	return t->gtime;
2074 }
2075 #endif
2076 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2077 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2078 
2079 /*
2080  * Per process flags
2081  */
2082 #define PF_EXITING	0x00000004	/* getting shut down */
2083 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
2084 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
2085 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
2086 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
2087 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
2088 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
2089 #define PF_DUMPCORE	0x00000200	/* dumped core */
2090 #define PF_SIGNALED	0x00000400	/* killed by a signal */
2091 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
2092 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
2093 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
2094 #define PF_USED_ASYNC	0x00004000	/* used async_schedule*(), used by module init */
2095 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
2096 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
2097 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
2098 #define PF_KSWAPD	0x00040000	/* I am kswapd */
2099 #define PF_MEMALLOC_NOIO 0x00080000	/* Allocating memory without IO involved */
2100 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
2101 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
2102 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
2103 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
2104 #define PF_NO_SETAFFINITY 0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
2105 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
2106 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
2107 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
2108 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
2109 
2110 /*
2111  * Only the _current_ task can read/write to tsk->flags, but other
2112  * tasks can access tsk->flags in readonly mode for example
2113  * with tsk_used_math (like during threaded core dumping).
2114  * There is however an exception to this rule during ptrace
2115  * or during fork: the ptracer task is allowed to write to the
2116  * child->flags of its traced child (same goes for fork, the parent
2117  * can write to the child->flags), because we're guaranteed the
2118  * child is not running and in turn not changing child->flags
2119  * at the same time the parent does it.
2120  */
2121 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2122 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2123 #define clear_used_math() clear_stopped_child_used_math(current)
2124 #define set_used_math() set_stopped_child_used_math(current)
2125 #define conditional_stopped_child_used_math(condition, child) \
2126 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2127 #define conditional_used_math(condition) \
2128 	conditional_stopped_child_used_math(condition, current)
2129 #define copy_to_stopped_child_used_math(child) \
2130 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2131 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2132 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2133 #define used_math() tsk_used_math(current)
2134 
2135 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2136  * __GFP_FS is also cleared as it implies __GFP_IO.
2137  */
2138 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2139 {
2140 	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2141 		flags &= ~(__GFP_IO | __GFP_FS);
2142 	return flags;
2143 }
2144 
2145 static inline unsigned int memalloc_noio_save(void)
2146 {
2147 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2148 	current->flags |= PF_MEMALLOC_NOIO;
2149 	return flags;
2150 }
2151 
2152 static inline void memalloc_noio_restore(unsigned int flags)
2153 {
2154 	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2155 }
2156 
2157 /* Per-process atomic flags. */
2158 #define PFA_NO_NEW_PRIVS 0	/* May not gain new privileges. */
2159 #define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2160 #define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2161 
2162 
2163 #define TASK_PFA_TEST(name, func)					\
2164 	static inline bool task_##func(struct task_struct *p)		\
2165 	{ return test_bit(PFA_##name, &p->atomic_flags); }
2166 #define TASK_PFA_SET(name, func)					\
2167 	static inline void task_set_##func(struct task_struct *p)	\
2168 	{ set_bit(PFA_##name, &p->atomic_flags); }
2169 #define TASK_PFA_CLEAR(name, func)					\
2170 	static inline void task_clear_##func(struct task_struct *p)	\
2171 	{ clear_bit(PFA_##name, &p->atomic_flags); }
2172 
2173 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2174 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2175 
2176 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2177 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2178 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2179 
2180 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2181 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2182 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2183 
2184 /*
2185  * task->jobctl flags
2186  */
2187 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
2188 
2189 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
2190 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
2191 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
2192 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
2193 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
2194 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
2195 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
2196 
2197 #define JOBCTL_STOP_DEQUEUED	(1UL << JOBCTL_STOP_DEQUEUED_BIT)
2198 #define JOBCTL_STOP_PENDING	(1UL << JOBCTL_STOP_PENDING_BIT)
2199 #define JOBCTL_STOP_CONSUME	(1UL << JOBCTL_STOP_CONSUME_BIT)
2200 #define JOBCTL_TRAP_STOP	(1UL << JOBCTL_TRAP_STOP_BIT)
2201 #define JOBCTL_TRAP_NOTIFY	(1UL << JOBCTL_TRAP_NOTIFY_BIT)
2202 #define JOBCTL_TRAPPING		(1UL << JOBCTL_TRAPPING_BIT)
2203 #define JOBCTL_LISTENING	(1UL << JOBCTL_LISTENING_BIT)
2204 
2205 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2206 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2207 
2208 extern bool task_set_jobctl_pending(struct task_struct *task,
2209 				    unsigned long mask);
2210 extern void task_clear_jobctl_trapping(struct task_struct *task);
2211 extern void task_clear_jobctl_pending(struct task_struct *task,
2212 				      unsigned long mask);
2213 
2214 static inline void rcu_copy_process(struct task_struct *p)
2215 {
2216 #ifdef CONFIG_PREEMPT_RCU
2217 	p->rcu_read_lock_nesting = 0;
2218 	p->rcu_read_unlock_special.s = 0;
2219 	p->rcu_blocked_node = NULL;
2220 	INIT_LIST_HEAD(&p->rcu_node_entry);
2221 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2222 #ifdef CONFIG_TASKS_RCU
2223 	p->rcu_tasks_holdout = false;
2224 	INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2225 	p->rcu_tasks_idle_cpu = -1;
2226 #endif /* #ifdef CONFIG_TASKS_RCU */
2227 }
2228 
2229 static inline void tsk_restore_flags(struct task_struct *task,
2230 				unsigned long orig_flags, unsigned long flags)
2231 {
2232 	task->flags &= ~flags;
2233 	task->flags |= orig_flags & flags;
2234 }
2235 
2236 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2237 				     const struct cpumask *trial);
2238 extern int task_can_attach(struct task_struct *p,
2239 			   const struct cpumask *cs_cpus_allowed);
2240 #ifdef CONFIG_SMP
2241 extern void do_set_cpus_allowed(struct task_struct *p,
2242 			       const struct cpumask *new_mask);
2243 
2244 extern int set_cpus_allowed_ptr(struct task_struct *p,
2245 				const struct cpumask *new_mask);
2246 #else
2247 static inline void do_set_cpus_allowed(struct task_struct *p,
2248 				      const struct cpumask *new_mask)
2249 {
2250 }
2251 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2252 				       const struct cpumask *new_mask)
2253 {
2254 	if (!cpumask_test_cpu(0, new_mask))
2255 		return -EINVAL;
2256 	return 0;
2257 }
2258 #endif
2259 
2260 #ifdef CONFIG_NO_HZ_COMMON
2261 void calc_load_enter_idle(void);
2262 void calc_load_exit_idle(void);
2263 #else
2264 static inline void calc_load_enter_idle(void) { }
2265 static inline void calc_load_exit_idle(void) { }
2266 #endif /* CONFIG_NO_HZ_COMMON */
2267 
2268 /*
2269  * Do not use outside of architecture code which knows its limitations.
2270  *
2271  * sched_clock() has no promise of monotonicity or bounded drift between
2272  * CPUs, use (which you should not) requires disabling IRQs.
2273  *
2274  * Please use one of the three interfaces below.
2275  */
2276 extern unsigned long long notrace sched_clock(void);
2277 /*
2278  * See the comment in kernel/sched/clock.c
2279  */
2280 extern u64 cpu_clock(int cpu);
2281 extern u64 local_clock(void);
2282 extern u64 running_clock(void);
2283 extern u64 sched_clock_cpu(int cpu);
2284 
2285 
2286 extern void sched_clock_init(void);
2287 
2288 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2289 static inline void sched_clock_tick(void)
2290 {
2291 }
2292 
2293 static inline void sched_clock_idle_sleep_event(void)
2294 {
2295 }
2296 
2297 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2298 {
2299 }
2300 #else
2301 /*
2302  * Architectures can set this to 1 if they have specified
2303  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2304  * but then during bootup it turns out that sched_clock()
2305  * is reliable after all:
2306  */
2307 extern int sched_clock_stable(void);
2308 extern void set_sched_clock_stable(void);
2309 extern void clear_sched_clock_stable(void);
2310 
2311 extern void sched_clock_tick(void);
2312 extern void sched_clock_idle_sleep_event(void);
2313 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2314 #endif
2315 
2316 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2317 /*
2318  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2319  * The reason for this explicit opt-in is not to have perf penalty with
2320  * slow sched_clocks.
2321  */
2322 extern void enable_sched_clock_irqtime(void);
2323 extern void disable_sched_clock_irqtime(void);
2324 #else
2325 static inline void enable_sched_clock_irqtime(void) {}
2326 static inline void disable_sched_clock_irqtime(void) {}
2327 #endif
2328 
2329 extern unsigned long long
2330 task_sched_runtime(struct task_struct *task);
2331 
2332 /* sched_exec is called by processes performing an exec */
2333 #ifdef CONFIG_SMP
2334 extern void sched_exec(void);
2335 #else
2336 #define sched_exec()   {}
2337 #endif
2338 
2339 extern void sched_clock_idle_sleep_event(void);
2340 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2341 
2342 #ifdef CONFIG_HOTPLUG_CPU
2343 extern void idle_task_exit(void);
2344 #else
2345 static inline void idle_task_exit(void) {}
2346 #endif
2347 
2348 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2349 extern void wake_up_nohz_cpu(int cpu);
2350 #else
2351 static inline void wake_up_nohz_cpu(int cpu) { }
2352 #endif
2353 
2354 #ifdef CONFIG_NO_HZ_FULL
2355 extern bool sched_can_stop_tick(void);
2356 extern u64 scheduler_tick_max_deferment(void);
2357 #else
2358 static inline bool sched_can_stop_tick(void) { return false; }
2359 #endif
2360 
2361 #ifdef CONFIG_SCHED_AUTOGROUP
2362 extern void sched_autogroup_create_attach(struct task_struct *p);
2363 extern void sched_autogroup_detach(struct task_struct *p);
2364 extern void sched_autogroup_fork(struct signal_struct *sig);
2365 extern void sched_autogroup_exit(struct signal_struct *sig);
2366 #ifdef CONFIG_PROC_FS
2367 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2368 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2369 #endif
2370 #else
2371 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2372 static inline void sched_autogroup_detach(struct task_struct *p) { }
2373 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2374 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2375 #endif
2376 
2377 extern int yield_to(struct task_struct *p, bool preempt);
2378 extern void set_user_nice(struct task_struct *p, long nice);
2379 extern int task_prio(const struct task_struct *p);
2380 /**
2381  * task_nice - return the nice value of a given task.
2382  * @p: the task in question.
2383  *
2384  * Return: The nice value [ -20 ... 0 ... 19 ].
2385  */
2386 static inline int task_nice(const struct task_struct *p)
2387 {
2388 	return PRIO_TO_NICE((p)->static_prio);
2389 }
2390 extern int can_nice(const struct task_struct *p, const int nice);
2391 extern int task_curr(const struct task_struct *p);
2392 extern int idle_cpu(int cpu);
2393 extern int sched_setscheduler(struct task_struct *, int,
2394 			      const struct sched_param *);
2395 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2396 				      const struct sched_param *);
2397 extern int sched_setattr(struct task_struct *,
2398 			 const struct sched_attr *);
2399 extern struct task_struct *idle_task(int cpu);
2400 /**
2401  * is_idle_task - is the specified task an idle task?
2402  * @p: the task in question.
2403  *
2404  * Return: 1 if @p is an idle task. 0 otherwise.
2405  */
2406 static inline bool is_idle_task(const struct task_struct *p)
2407 {
2408 	return p->pid == 0;
2409 }
2410 extern struct task_struct *curr_task(int cpu);
2411 extern void set_curr_task(int cpu, struct task_struct *p);
2412 
2413 void yield(void);
2414 
2415 union thread_union {
2416 	struct thread_info thread_info;
2417 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2418 };
2419 
2420 #ifndef __HAVE_ARCH_KSTACK_END
2421 static inline int kstack_end(void *addr)
2422 {
2423 	/* Reliable end of stack detection:
2424 	 * Some APM bios versions misalign the stack
2425 	 */
2426 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2427 }
2428 #endif
2429 
2430 extern union thread_union init_thread_union;
2431 extern struct task_struct init_task;
2432 
2433 extern struct   mm_struct init_mm;
2434 
2435 extern struct pid_namespace init_pid_ns;
2436 
2437 /*
2438  * find a task by one of its numerical ids
2439  *
2440  * find_task_by_pid_ns():
2441  *      finds a task by its pid in the specified namespace
2442  * find_task_by_vpid():
2443  *      finds a task by its virtual pid
2444  *
2445  * see also find_vpid() etc in include/linux/pid.h
2446  */
2447 
2448 extern struct task_struct *find_task_by_vpid(pid_t nr);
2449 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2450 		struct pid_namespace *ns);
2451 
2452 /* per-UID process charging. */
2453 extern struct user_struct * alloc_uid(kuid_t);
2454 static inline struct user_struct *get_uid(struct user_struct *u)
2455 {
2456 	atomic_inc(&u->__count);
2457 	return u;
2458 }
2459 extern void free_uid(struct user_struct *);
2460 
2461 #include <asm/current.h>
2462 
2463 extern void xtime_update(unsigned long ticks);
2464 
2465 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2466 extern int wake_up_process(struct task_struct *tsk);
2467 extern void wake_up_new_task(struct task_struct *tsk);
2468 #ifdef CONFIG_SMP
2469  extern void kick_process(struct task_struct *tsk);
2470 #else
2471  static inline void kick_process(struct task_struct *tsk) { }
2472 #endif
2473 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2474 extern void sched_dead(struct task_struct *p);
2475 
2476 extern void proc_caches_init(void);
2477 extern void flush_signals(struct task_struct *);
2478 extern void ignore_signals(struct task_struct *);
2479 extern void flush_signal_handlers(struct task_struct *, int force_default);
2480 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2481 
2482 static inline int kernel_dequeue_signal(siginfo_t *info)
2483 {
2484 	struct task_struct *tsk = current;
2485 	siginfo_t __info;
2486 	int ret;
2487 
2488 	spin_lock_irq(&tsk->sighand->siglock);
2489 	ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
2490 	spin_unlock_irq(&tsk->sighand->siglock);
2491 
2492 	return ret;
2493 }
2494 
2495 static inline void kernel_signal_stop(void)
2496 {
2497 	spin_lock_irq(&current->sighand->siglock);
2498 	if (current->jobctl & JOBCTL_STOP_DEQUEUED)
2499 		__set_current_state(TASK_STOPPED);
2500 	spin_unlock_irq(&current->sighand->siglock);
2501 
2502 	schedule();
2503 }
2504 
2505 extern void release_task(struct task_struct * p);
2506 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2507 extern int force_sigsegv(int, struct task_struct *);
2508 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2509 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2510 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2511 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2512 				const struct cred *, u32);
2513 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2514 extern int kill_pid(struct pid *pid, int sig, int priv);
2515 extern int kill_proc_info(int, struct siginfo *, pid_t);
2516 extern __must_check bool do_notify_parent(struct task_struct *, int);
2517 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2518 extern void force_sig(int, struct task_struct *);
2519 extern int send_sig(int, struct task_struct *, int);
2520 extern int zap_other_threads(struct task_struct *p);
2521 extern struct sigqueue *sigqueue_alloc(void);
2522 extern void sigqueue_free(struct sigqueue *);
2523 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2524 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2525 
2526 static inline void restore_saved_sigmask(void)
2527 {
2528 	if (test_and_clear_restore_sigmask())
2529 		__set_current_blocked(&current->saved_sigmask);
2530 }
2531 
2532 static inline sigset_t *sigmask_to_save(void)
2533 {
2534 	sigset_t *res = &current->blocked;
2535 	if (unlikely(test_restore_sigmask()))
2536 		res = &current->saved_sigmask;
2537 	return res;
2538 }
2539 
2540 static inline int kill_cad_pid(int sig, int priv)
2541 {
2542 	return kill_pid(cad_pid, sig, priv);
2543 }
2544 
2545 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2546 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2547 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2548 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2549 
2550 /*
2551  * True if we are on the alternate signal stack.
2552  */
2553 static inline int on_sig_stack(unsigned long sp)
2554 {
2555 #ifdef CONFIG_STACK_GROWSUP
2556 	return sp >= current->sas_ss_sp &&
2557 		sp - current->sas_ss_sp < current->sas_ss_size;
2558 #else
2559 	return sp > current->sas_ss_sp &&
2560 		sp - current->sas_ss_sp <= current->sas_ss_size;
2561 #endif
2562 }
2563 
2564 static inline int sas_ss_flags(unsigned long sp)
2565 {
2566 	if (!current->sas_ss_size)
2567 		return SS_DISABLE;
2568 
2569 	return on_sig_stack(sp) ? SS_ONSTACK : 0;
2570 }
2571 
2572 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2573 {
2574 	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2575 #ifdef CONFIG_STACK_GROWSUP
2576 		return current->sas_ss_sp;
2577 #else
2578 		return current->sas_ss_sp + current->sas_ss_size;
2579 #endif
2580 	return sp;
2581 }
2582 
2583 /*
2584  * Routines for handling mm_structs
2585  */
2586 extern struct mm_struct * mm_alloc(void);
2587 
2588 /* mmdrop drops the mm and the page tables */
2589 extern void __mmdrop(struct mm_struct *);
2590 static inline void mmdrop(struct mm_struct * mm)
2591 {
2592 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2593 		__mmdrop(mm);
2594 }
2595 
2596 /* mmput gets rid of the mappings and all user-space */
2597 extern void mmput(struct mm_struct *);
2598 /* Grab a reference to a task's mm, if it is not already going away */
2599 extern struct mm_struct *get_task_mm(struct task_struct *task);
2600 /*
2601  * Grab a reference to a task's mm, if it is not already going away
2602  * and ptrace_may_access with the mode parameter passed to it
2603  * succeeds.
2604  */
2605 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2606 /* Remove the current tasks stale references to the old mm_struct */
2607 extern void mm_release(struct task_struct *, struct mm_struct *);
2608 
2609 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
2610 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2611 			struct task_struct *, unsigned long);
2612 #else
2613 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2614 			struct task_struct *);
2615 
2616 /* Architectures that haven't opted into copy_thread_tls get the tls argument
2617  * via pt_regs, so ignore the tls argument passed via C. */
2618 static inline int copy_thread_tls(
2619 		unsigned long clone_flags, unsigned long sp, unsigned long arg,
2620 		struct task_struct *p, unsigned long tls)
2621 {
2622 	return copy_thread(clone_flags, sp, arg, p);
2623 }
2624 #endif
2625 extern void flush_thread(void);
2626 extern void exit_thread(void);
2627 
2628 extern void exit_files(struct task_struct *);
2629 extern void __cleanup_sighand(struct sighand_struct *);
2630 
2631 extern void exit_itimers(struct signal_struct *);
2632 extern void flush_itimer_signals(void);
2633 
2634 extern void do_group_exit(int);
2635 
2636 extern int do_execve(struct filename *,
2637 		     const char __user * const __user *,
2638 		     const char __user * const __user *);
2639 extern int do_execveat(int, struct filename *,
2640 		       const char __user * const __user *,
2641 		       const char __user * const __user *,
2642 		       int);
2643 extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
2644 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2645 struct task_struct *fork_idle(int);
2646 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2647 
2648 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2649 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2650 {
2651 	__set_task_comm(tsk, from, false);
2652 }
2653 extern char *get_task_comm(char *to, struct task_struct *tsk);
2654 
2655 #ifdef CONFIG_SMP
2656 void scheduler_ipi(void);
2657 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2658 #else
2659 static inline void scheduler_ipi(void) { }
2660 static inline unsigned long wait_task_inactive(struct task_struct *p,
2661 					       long match_state)
2662 {
2663 	return 1;
2664 }
2665 #endif
2666 
2667 #define tasklist_empty() \
2668 	list_empty(&init_task.tasks)
2669 
2670 #define next_task(p) \
2671 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2672 
2673 #define for_each_process(p) \
2674 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2675 
2676 extern bool current_is_single_threaded(void);
2677 
2678 /*
2679  * Careful: do_each_thread/while_each_thread is a double loop so
2680  *          'break' will not work as expected - use goto instead.
2681  */
2682 #define do_each_thread(g, t) \
2683 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2684 
2685 #define while_each_thread(g, t) \
2686 	while ((t = next_thread(t)) != g)
2687 
2688 #define __for_each_thread(signal, t)	\
2689 	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2690 
2691 #define for_each_thread(p, t)		\
2692 	__for_each_thread((p)->signal, t)
2693 
2694 /* Careful: this is a double loop, 'break' won't work as expected. */
2695 #define for_each_process_thread(p, t)	\
2696 	for_each_process(p) for_each_thread(p, t)
2697 
2698 static inline int get_nr_threads(struct task_struct *tsk)
2699 {
2700 	return tsk->signal->nr_threads;
2701 }
2702 
2703 static inline bool thread_group_leader(struct task_struct *p)
2704 {
2705 	return p->exit_signal >= 0;
2706 }
2707 
2708 /* Do to the insanities of de_thread it is possible for a process
2709  * to have the pid of the thread group leader without actually being
2710  * the thread group leader.  For iteration through the pids in proc
2711  * all we care about is that we have a task with the appropriate
2712  * pid, we don't actually care if we have the right task.
2713  */
2714 static inline bool has_group_leader_pid(struct task_struct *p)
2715 {
2716 	return task_pid(p) == p->signal->leader_pid;
2717 }
2718 
2719 static inline
2720 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2721 {
2722 	return p1->signal == p2->signal;
2723 }
2724 
2725 static inline struct task_struct *next_thread(const struct task_struct *p)
2726 {
2727 	return list_entry_rcu(p->thread_group.next,
2728 			      struct task_struct, thread_group);
2729 }
2730 
2731 static inline int thread_group_empty(struct task_struct *p)
2732 {
2733 	return list_empty(&p->thread_group);
2734 }
2735 
2736 #define delay_group_leader(p) \
2737 		(thread_group_leader(p) && !thread_group_empty(p))
2738 
2739 /*
2740  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2741  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2742  * pins the final release of task.io_context.  Also protects ->cpuset and
2743  * ->cgroup.subsys[]. And ->vfork_done.
2744  *
2745  * Nests both inside and outside of read_lock(&tasklist_lock).
2746  * It must not be nested with write_lock_irq(&tasklist_lock),
2747  * neither inside nor outside.
2748  */
2749 static inline void task_lock(struct task_struct *p)
2750 {
2751 	spin_lock(&p->alloc_lock);
2752 }
2753 
2754 static inline void task_unlock(struct task_struct *p)
2755 {
2756 	spin_unlock(&p->alloc_lock);
2757 }
2758 
2759 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2760 							unsigned long *flags);
2761 
2762 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2763 						       unsigned long *flags)
2764 {
2765 	struct sighand_struct *ret;
2766 
2767 	ret = __lock_task_sighand(tsk, flags);
2768 	(void)__cond_lock(&tsk->sighand->siglock, ret);
2769 	return ret;
2770 }
2771 
2772 static inline void unlock_task_sighand(struct task_struct *tsk,
2773 						unsigned long *flags)
2774 {
2775 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2776 }
2777 
2778 /**
2779  * threadgroup_change_begin - mark the beginning of changes to a threadgroup
2780  * @tsk: task causing the changes
2781  *
2782  * All operations which modify a threadgroup - a new thread joining the
2783  * group, death of a member thread (the assertion of PF_EXITING) and
2784  * exec(2) dethreading the process and replacing the leader - are wrapped
2785  * by threadgroup_change_{begin|end}().  This is to provide a place which
2786  * subsystems needing threadgroup stability can hook into for
2787  * synchronization.
2788  */
2789 static inline void threadgroup_change_begin(struct task_struct *tsk)
2790 {
2791 	might_sleep();
2792 	cgroup_threadgroup_change_begin(tsk);
2793 }
2794 
2795 /**
2796  * threadgroup_change_end - mark the end of changes to a threadgroup
2797  * @tsk: task causing the changes
2798  *
2799  * See threadgroup_change_begin().
2800  */
2801 static inline void threadgroup_change_end(struct task_struct *tsk)
2802 {
2803 	cgroup_threadgroup_change_end(tsk);
2804 }
2805 
2806 #ifndef __HAVE_THREAD_FUNCTIONS
2807 
2808 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2809 #define task_stack_page(task)	((task)->stack)
2810 
2811 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2812 {
2813 	*task_thread_info(p) = *task_thread_info(org);
2814 	task_thread_info(p)->task = p;
2815 }
2816 
2817 /*
2818  * Return the address of the last usable long on the stack.
2819  *
2820  * When the stack grows down, this is just above the thread
2821  * info struct. Going any lower will corrupt the threadinfo.
2822  *
2823  * When the stack grows up, this is the highest address.
2824  * Beyond that position, we corrupt data on the next page.
2825  */
2826 static inline unsigned long *end_of_stack(struct task_struct *p)
2827 {
2828 #ifdef CONFIG_STACK_GROWSUP
2829 	return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2830 #else
2831 	return (unsigned long *)(task_thread_info(p) + 1);
2832 #endif
2833 }
2834 
2835 #endif
2836 #define task_stack_end_corrupted(task) \
2837 		(*(end_of_stack(task)) != STACK_END_MAGIC)
2838 
2839 static inline int object_is_on_stack(void *obj)
2840 {
2841 	void *stack = task_stack_page(current);
2842 
2843 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2844 }
2845 
2846 extern void thread_info_cache_init(void);
2847 
2848 #ifdef CONFIG_DEBUG_STACK_USAGE
2849 static inline unsigned long stack_not_used(struct task_struct *p)
2850 {
2851 	unsigned long *n = end_of_stack(p);
2852 
2853 	do { 	/* Skip over canary */
2854 		n++;
2855 	} while (!*n);
2856 
2857 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2858 }
2859 #endif
2860 extern void set_task_stack_end_magic(struct task_struct *tsk);
2861 
2862 /* set thread flags in other task's structures
2863  * - see asm/thread_info.h for TIF_xxxx flags available
2864  */
2865 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2866 {
2867 	set_ti_thread_flag(task_thread_info(tsk), flag);
2868 }
2869 
2870 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2871 {
2872 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2873 }
2874 
2875 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2876 {
2877 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2878 }
2879 
2880 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2881 {
2882 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2883 }
2884 
2885 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2886 {
2887 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2888 }
2889 
2890 static inline void set_tsk_need_resched(struct task_struct *tsk)
2891 {
2892 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2893 }
2894 
2895 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2896 {
2897 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2898 }
2899 
2900 static inline int test_tsk_need_resched(struct task_struct *tsk)
2901 {
2902 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2903 }
2904 
2905 static inline int restart_syscall(void)
2906 {
2907 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2908 	return -ERESTARTNOINTR;
2909 }
2910 
2911 static inline int signal_pending(struct task_struct *p)
2912 {
2913 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2914 }
2915 
2916 static inline int __fatal_signal_pending(struct task_struct *p)
2917 {
2918 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2919 }
2920 
2921 static inline int fatal_signal_pending(struct task_struct *p)
2922 {
2923 	return signal_pending(p) && __fatal_signal_pending(p);
2924 }
2925 
2926 static inline int signal_pending_state(long state, struct task_struct *p)
2927 {
2928 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2929 		return 0;
2930 	if (!signal_pending(p))
2931 		return 0;
2932 
2933 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2934 }
2935 
2936 /*
2937  * cond_resched() and cond_resched_lock(): latency reduction via
2938  * explicit rescheduling in places that are safe. The return
2939  * value indicates whether a reschedule was done in fact.
2940  * cond_resched_lock() will drop the spinlock before scheduling,
2941  * cond_resched_softirq() will enable bhs before scheduling.
2942  */
2943 extern int _cond_resched(void);
2944 
2945 #define cond_resched() ({			\
2946 	___might_sleep(__FILE__, __LINE__, 0);	\
2947 	_cond_resched();			\
2948 })
2949 
2950 extern int __cond_resched_lock(spinlock_t *lock);
2951 
2952 #define cond_resched_lock(lock) ({				\
2953 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2954 	__cond_resched_lock(lock);				\
2955 })
2956 
2957 extern int __cond_resched_softirq(void);
2958 
2959 #define cond_resched_softirq() ({					\
2960 	___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2961 	__cond_resched_softirq();					\
2962 })
2963 
2964 static inline void cond_resched_rcu(void)
2965 {
2966 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2967 	rcu_read_unlock();
2968 	cond_resched();
2969 	rcu_read_lock();
2970 #endif
2971 }
2972 
2973 /*
2974  * Does a critical section need to be broken due to another
2975  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2976  * but a general need for low latency)
2977  */
2978 static inline int spin_needbreak(spinlock_t *lock)
2979 {
2980 #ifdef CONFIG_PREEMPT
2981 	return spin_is_contended(lock);
2982 #else
2983 	return 0;
2984 #endif
2985 }
2986 
2987 /*
2988  * Idle thread specific functions to determine the need_resched
2989  * polling state.
2990  */
2991 #ifdef TIF_POLLING_NRFLAG
2992 static inline int tsk_is_polling(struct task_struct *p)
2993 {
2994 	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2995 }
2996 
2997 static inline void __current_set_polling(void)
2998 {
2999 	set_thread_flag(TIF_POLLING_NRFLAG);
3000 }
3001 
3002 static inline bool __must_check current_set_polling_and_test(void)
3003 {
3004 	__current_set_polling();
3005 
3006 	/*
3007 	 * Polling state must be visible before we test NEED_RESCHED,
3008 	 * paired by resched_curr()
3009 	 */
3010 	smp_mb__after_atomic();
3011 
3012 	return unlikely(tif_need_resched());
3013 }
3014 
3015 static inline void __current_clr_polling(void)
3016 {
3017 	clear_thread_flag(TIF_POLLING_NRFLAG);
3018 }
3019 
3020 static inline bool __must_check current_clr_polling_and_test(void)
3021 {
3022 	__current_clr_polling();
3023 
3024 	/*
3025 	 * Polling state must be visible before we test NEED_RESCHED,
3026 	 * paired by resched_curr()
3027 	 */
3028 	smp_mb__after_atomic();
3029 
3030 	return unlikely(tif_need_resched());
3031 }
3032 
3033 #else
3034 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
3035 static inline void __current_set_polling(void) { }
3036 static inline void __current_clr_polling(void) { }
3037 
3038 static inline bool __must_check current_set_polling_and_test(void)
3039 {
3040 	return unlikely(tif_need_resched());
3041 }
3042 static inline bool __must_check current_clr_polling_and_test(void)
3043 {
3044 	return unlikely(tif_need_resched());
3045 }
3046 #endif
3047 
3048 static inline void current_clr_polling(void)
3049 {
3050 	__current_clr_polling();
3051 
3052 	/*
3053 	 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3054 	 * Once the bit is cleared, we'll get IPIs with every new
3055 	 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3056 	 * fold.
3057 	 */
3058 	smp_mb(); /* paired with resched_curr() */
3059 
3060 	preempt_fold_need_resched();
3061 }
3062 
3063 static __always_inline bool need_resched(void)
3064 {
3065 	return unlikely(tif_need_resched());
3066 }
3067 
3068 /*
3069  * Thread group CPU time accounting.
3070  */
3071 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3072 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3073 
3074 /*
3075  * Reevaluate whether the task has signals pending delivery.
3076  * Wake the task if so.
3077  * This is required every time the blocked sigset_t changes.
3078  * callers must hold sighand->siglock.
3079  */
3080 extern void recalc_sigpending_and_wake(struct task_struct *t);
3081 extern void recalc_sigpending(void);
3082 
3083 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3084 
3085 static inline void signal_wake_up(struct task_struct *t, bool resume)
3086 {
3087 	signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3088 }
3089 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3090 {
3091 	signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3092 }
3093 
3094 /*
3095  * Wrappers for p->thread_info->cpu access. No-op on UP.
3096  */
3097 #ifdef CONFIG_SMP
3098 
3099 static inline unsigned int task_cpu(const struct task_struct *p)
3100 {
3101 	return task_thread_info(p)->cpu;
3102 }
3103 
3104 static inline int task_node(const struct task_struct *p)
3105 {
3106 	return cpu_to_node(task_cpu(p));
3107 }
3108 
3109 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3110 
3111 #else
3112 
3113 static inline unsigned int task_cpu(const struct task_struct *p)
3114 {
3115 	return 0;
3116 }
3117 
3118 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3119 {
3120 }
3121 
3122 #endif /* CONFIG_SMP */
3123 
3124 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3125 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3126 
3127 #ifdef CONFIG_CGROUP_SCHED
3128 extern struct task_group root_task_group;
3129 #endif /* CONFIG_CGROUP_SCHED */
3130 
3131 extern int task_can_switch_user(struct user_struct *up,
3132 					struct task_struct *tsk);
3133 
3134 #ifdef CONFIG_TASK_XACCT
3135 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3136 {
3137 	tsk->ioac.rchar += amt;
3138 }
3139 
3140 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3141 {
3142 	tsk->ioac.wchar += amt;
3143 }
3144 
3145 static inline void inc_syscr(struct task_struct *tsk)
3146 {
3147 	tsk->ioac.syscr++;
3148 }
3149 
3150 static inline void inc_syscw(struct task_struct *tsk)
3151 {
3152 	tsk->ioac.syscw++;
3153 }
3154 #else
3155 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3156 {
3157 }
3158 
3159 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3160 {
3161 }
3162 
3163 static inline void inc_syscr(struct task_struct *tsk)
3164 {
3165 }
3166 
3167 static inline void inc_syscw(struct task_struct *tsk)
3168 {
3169 }
3170 #endif
3171 
3172 #ifndef TASK_SIZE_OF
3173 #define TASK_SIZE_OF(tsk)	TASK_SIZE
3174 #endif
3175 
3176 #ifdef CONFIG_MEMCG
3177 extern void mm_update_next_owner(struct mm_struct *mm);
3178 #else
3179 static inline void mm_update_next_owner(struct mm_struct *mm)
3180 {
3181 }
3182 #endif /* CONFIG_MEMCG */
3183 
3184 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3185 		unsigned int limit)
3186 {
3187 	return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3188 }
3189 
3190 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3191 		unsigned int limit)
3192 {
3193 	return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3194 }
3195 
3196 static inline unsigned long rlimit(unsigned int limit)
3197 {
3198 	return task_rlimit(current, limit);
3199 }
3200 
3201 static inline unsigned long rlimit_max(unsigned int limit)
3202 {
3203 	return task_rlimit_max(current, limit);
3204 }
3205 
3206 #endif
3207