xref: /linux-6.15/include/linux/sched.h (revision 077248fc)
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3 
4 /*
5  * cloning flags:
6  */
7 #define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
8 #define CLONE_VM	0x00000100	/* set if VM shared between processes */
9 #define CLONE_FS	0x00000200	/* set if fs info shared between processes */
10 #define CLONE_FILES	0x00000400	/* set if open files shared between processes */
11 #define CLONE_SIGHAND	0x00000800	/* set if signal handlers and blocked signals shared */
12 #define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
13 #define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */
14 #define CLONE_PARENT	0x00008000	/* set if we want to have the same parent as the cloner */
15 #define CLONE_THREAD	0x00010000	/* Same thread group? */
16 #define CLONE_NEWNS	0x00020000	/* New namespace group? */
17 #define CLONE_SYSVSEM	0x00040000	/* share system V SEM_UNDO semantics */
18 #define CLONE_SETTLS	0x00080000	/* create a new TLS for the child */
19 #define CLONE_PARENT_SETTID	0x00100000	/* set the TID in the parent */
20 #define CLONE_CHILD_CLEARTID	0x00200000	/* clear the TID in the child */
21 #define CLONE_DETACHED		0x00400000	/* Unused, ignored */
22 #define CLONE_UNTRACED		0x00800000	/* set if the tracing process can't force CLONE_PTRACE on this clone */
23 #define CLONE_CHILD_SETTID	0x01000000	/* set the TID in the child */
24 #define CLONE_STOPPED		0x02000000	/* Start in stopped state */
25 #define CLONE_NEWUTS		0x04000000	/* New utsname group? */
26 #define CLONE_NEWIPC		0x08000000	/* New ipcs */
27 #define CLONE_NEWUSER		0x10000000	/* New user namespace */
28 #define CLONE_NEWPID		0x20000000	/* New pid namespace */
29 #define CLONE_NEWNET		0x40000000	/* New network namespace */
30 #define CLONE_IO		0x80000000	/* Clone io context */
31 
32 /*
33  * Scheduling policies
34  */
35 #define SCHED_NORMAL		0
36 #define SCHED_FIFO		1
37 #define SCHED_RR		2
38 #define SCHED_BATCH		3
39 /* SCHED_ISO: reserved but not implemented yet */
40 #define SCHED_IDLE		5
41 /* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
42 #define SCHED_RESET_ON_FORK     0x40000000
43 
44 #ifdef __KERNEL__
45 
46 struct sched_param {
47 	int sched_priority;
48 };
49 
50 #include <asm/param.h>	/* for HZ */
51 
52 #include <linux/capability.h>
53 #include <linux/threads.h>
54 #include <linux/kernel.h>
55 #include <linux/types.h>
56 #include <linux/timex.h>
57 #include <linux/jiffies.h>
58 #include <linux/rbtree.h>
59 #include <linux/thread_info.h>
60 #include <linux/cpumask.h>
61 #include <linux/errno.h>
62 #include <linux/nodemask.h>
63 #include <linux/mm_types.h>
64 
65 #include <asm/system.h>
66 #include <asm/page.h>
67 #include <asm/ptrace.h>
68 #include <asm/cputime.h>
69 
70 #include <linux/smp.h>
71 #include <linux/sem.h>
72 #include <linux/signal.h>
73 #include <linux/path.h>
74 #include <linux/compiler.h>
75 #include <linux/completion.h>
76 #include <linux/pid.h>
77 #include <linux/percpu.h>
78 #include <linux/topology.h>
79 #include <linux/proportions.h>
80 #include <linux/seccomp.h>
81 #include <linux/rcupdate.h>
82 #include <linux/rculist.h>
83 #include <linux/rtmutex.h>
84 
85 #include <linux/time.h>
86 #include <linux/param.h>
87 #include <linux/resource.h>
88 #include <linux/timer.h>
89 #include <linux/hrtimer.h>
90 #include <linux/task_io_accounting.h>
91 #include <linux/kobject.h>
92 #include <linux/latencytop.h>
93 #include <linux/cred.h>
94 
95 #include <asm/processor.h>
96 
97 struct exec_domain;
98 struct futex_pi_state;
99 struct robust_list_head;
100 struct bio_list;
101 struct fs_struct;
102 struct perf_event_context;
103 
104 /*
105  * List of flags we want to share for kernel threads,
106  * if only because they are not used by them anyway.
107  */
108 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
109 
110 /*
111  * These are the constant used to fake the fixed-point load-average
112  * counting. Some notes:
113  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
114  *    a load-average precision of 10 bits integer + 11 bits fractional
115  *  - if you want to count load-averages more often, you need more
116  *    precision, or rounding will get you. With 2-second counting freq,
117  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
118  *    11 bit fractions.
119  */
120 extern unsigned long avenrun[];		/* Load averages */
121 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
122 
123 #define FSHIFT		11		/* nr of bits of precision */
124 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
125 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
126 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
127 #define EXP_5		2014		/* 1/exp(5sec/5min) */
128 #define EXP_15		2037		/* 1/exp(5sec/15min) */
129 
130 #define CALC_LOAD(load,exp,n) \
131 	load *= exp; \
132 	load += n*(FIXED_1-exp); \
133 	load >>= FSHIFT;
134 
135 extern unsigned long total_forks;
136 extern int nr_threads;
137 DECLARE_PER_CPU(unsigned long, process_counts);
138 extern int nr_processes(void);
139 extern unsigned long nr_running(void);
140 extern unsigned long nr_uninterruptible(void);
141 extern unsigned long nr_iowait(void);
142 extern unsigned long nr_iowait_cpu(int cpu);
143 extern unsigned long this_cpu_load(void);
144 
145 
146 extern void calc_global_load(void);
147 
148 extern unsigned long get_parent_ip(unsigned long addr);
149 
150 struct seq_file;
151 struct cfs_rq;
152 struct task_group;
153 #ifdef CONFIG_SCHED_DEBUG
154 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
155 extern void proc_sched_set_task(struct task_struct *p);
156 extern void
157 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
158 #else
159 static inline void
160 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
161 {
162 }
163 static inline void proc_sched_set_task(struct task_struct *p)
164 {
165 }
166 static inline void
167 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
168 {
169 }
170 #endif
171 
172 /*
173  * Task state bitmask. NOTE! These bits are also
174  * encoded in fs/proc/array.c: get_task_state().
175  *
176  * We have two separate sets of flags: task->state
177  * is about runnability, while task->exit_state are
178  * about the task exiting. Confusing, but this way
179  * modifying one set can't modify the other one by
180  * mistake.
181  */
182 #define TASK_RUNNING		0
183 #define TASK_INTERRUPTIBLE	1
184 #define TASK_UNINTERRUPTIBLE	2
185 #define __TASK_STOPPED		4
186 #define __TASK_TRACED		8
187 /* in tsk->exit_state */
188 #define EXIT_ZOMBIE		16
189 #define EXIT_DEAD		32
190 /* in tsk->state again */
191 #define TASK_DEAD		64
192 #define TASK_WAKEKILL		128
193 #define TASK_WAKING		256
194 #define TASK_STATE_MAX		512
195 
196 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
197 
198 extern char ___assert_task_state[1 - 2*!!(
199 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
200 
201 /* Convenience macros for the sake of set_task_state */
202 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
203 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
204 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
205 
206 /* Convenience macros for the sake of wake_up */
207 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
208 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
209 
210 /* get_task_state() */
211 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
212 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
213 				 __TASK_TRACED)
214 
215 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
216 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
217 #define task_is_dead(task)	((task)->exit_state != 0)
218 #define task_is_stopped_or_traced(task)	\
219 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
220 #define task_contributes_to_load(task)	\
221 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
222 				 (task->flags & PF_FREEZING) == 0)
223 
224 #define __set_task_state(tsk, state_value)		\
225 	do { (tsk)->state = (state_value); } while (0)
226 #define set_task_state(tsk, state_value)		\
227 	set_mb((tsk)->state, (state_value))
228 
229 /*
230  * set_current_state() includes a barrier so that the write of current->state
231  * is correctly serialised wrt the caller's subsequent test of whether to
232  * actually sleep:
233  *
234  *	set_current_state(TASK_UNINTERRUPTIBLE);
235  *	if (do_i_need_to_sleep())
236  *		schedule();
237  *
238  * If the caller does not need such serialisation then use __set_current_state()
239  */
240 #define __set_current_state(state_value)			\
241 	do { current->state = (state_value); } while (0)
242 #define set_current_state(state_value)		\
243 	set_mb(current->state, (state_value))
244 
245 /* Task command name length */
246 #define TASK_COMM_LEN 16
247 
248 #include <linux/spinlock.h>
249 
250 /*
251  * This serializes "schedule()" and also protects
252  * the run-queue from deletions/modifications (but
253  * _adding_ to the beginning of the run-queue has
254  * a separate lock).
255  */
256 extern rwlock_t tasklist_lock;
257 extern spinlock_t mmlist_lock;
258 
259 struct task_struct;
260 
261 #ifdef CONFIG_PROVE_RCU
262 extern int lockdep_tasklist_lock_is_held(void);
263 #endif /* #ifdef CONFIG_PROVE_RCU */
264 
265 extern void sched_init(void);
266 extern void sched_init_smp(void);
267 extern asmlinkage void schedule_tail(struct task_struct *prev);
268 extern void init_idle(struct task_struct *idle, int cpu);
269 extern void init_idle_bootup_task(struct task_struct *idle);
270 
271 extern int runqueue_is_locked(int cpu);
272 
273 extern cpumask_var_t nohz_cpu_mask;
274 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
275 extern void select_nohz_load_balancer(int stop_tick);
276 extern int get_nohz_timer_target(void);
277 #else
278 static inline void select_nohz_load_balancer(int stop_tick) { }
279 #endif
280 
281 /*
282  * Only dump TASK_* tasks. (0 for all tasks)
283  */
284 extern void show_state_filter(unsigned long state_filter);
285 
286 static inline void show_state(void)
287 {
288 	show_state_filter(0);
289 }
290 
291 extern void show_regs(struct pt_regs *);
292 
293 /*
294  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
295  * task), SP is the stack pointer of the first frame that should be shown in the back
296  * trace (or NULL if the entire call-chain of the task should be shown).
297  */
298 extern void show_stack(struct task_struct *task, unsigned long *sp);
299 
300 void io_schedule(void);
301 long io_schedule_timeout(long timeout);
302 
303 extern void cpu_init (void);
304 extern void trap_init(void);
305 extern void update_process_times(int user);
306 extern void scheduler_tick(void);
307 
308 extern void sched_show_task(struct task_struct *p);
309 
310 #ifdef CONFIG_LOCKUP_DETECTOR
311 extern void touch_softlockup_watchdog(void);
312 extern void touch_softlockup_watchdog_sync(void);
313 extern void touch_all_softlockup_watchdogs(void);
314 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
315 				  void __user *buffer,
316 				  size_t *lenp, loff_t *ppos);
317 extern unsigned int  softlockup_panic;
318 extern int softlockup_thresh;
319 #else
320 static inline void touch_softlockup_watchdog(void)
321 {
322 }
323 static inline void touch_softlockup_watchdog_sync(void)
324 {
325 }
326 static inline void touch_all_softlockup_watchdogs(void)
327 {
328 }
329 #endif
330 
331 #ifdef CONFIG_DETECT_HUNG_TASK
332 extern unsigned int  sysctl_hung_task_panic;
333 extern unsigned long sysctl_hung_task_check_count;
334 extern unsigned long sysctl_hung_task_timeout_secs;
335 extern unsigned long sysctl_hung_task_warnings;
336 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
337 					 void __user *buffer,
338 					 size_t *lenp, loff_t *ppos);
339 #else
340 /* Avoid need for ifdefs elsewhere in the code */
341 enum { sysctl_hung_task_timeout_secs = 0 };
342 #endif
343 
344 /* Attach to any functions which should be ignored in wchan output. */
345 #define __sched		__attribute__((__section__(".sched.text")))
346 
347 /* Linker adds these: start and end of __sched functions */
348 extern char __sched_text_start[], __sched_text_end[];
349 
350 /* Is this address in the __sched functions? */
351 extern int in_sched_functions(unsigned long addr);
352 
353 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
354 extern signed long schedule_timeout(signed long timeout);
355 extern signed long schedule_timeout_interruptible(signed long timeout);
356 extern signed long schedule_timeout_killable(signed long timeout);
357 extern signed long schedule_timeout_uninterruptible(signed long timeout);
358 asmlinkage void schedule(void);
359 extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
360 
361 struct nsproxy;
362 struct user_namespace;
363 
364 /*
365  * Default maximum number of active map areas, this limits the number of vmas
366  * per mm struct. Users can overwrite this number by sysctl but there is a
367  * problem.
368  *
369  * When a program's coredump is generated as ELF format, a section is created
370  * per a vma. In ELF, the number of sections is represented in unsigned short.
371  * This means the number of sections should be smaller than 65535 at coredump.
372  * Because the kernel adds some informative sections to a image of program at
373  * generating coredump, we need some margin. The number of extra sections is
374  * 1-3 now and depends on arch. We use "5" as safe margin, here.
375  */
376 #define MAPCOUNT_ELF_CORE_MARGIN	(5)
377 #define DEFAULT_MAX_MAP_COUNT	(USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
378 
379 extern int sysctl_max_map_count;
380 
381 #include <linux/aio.h>
382 
383 #ifdef CONFIG_MMU
384 extern void arch_pick_mmap_layout(struct mm_struct *mm);
385 extern unsigned long
386 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
387 		       unsigned long, unsigned long);
388 extern unsigned long
389 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
390 			  unsigned long len, unsigned long pgoff,
391 			  unsigned long flags);
392 extern void arch_unmap_area(struct mm_struct *, unsigned long);
393 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
394 #else
395 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
396 #endif
397 
398 
399 extern void set_dumpable(struct mm_struct *mm, int value);
400 extern int get_dumpable(struct mm_struct *mm);
401 
402 /* mm flags */
403 /* dumpable bits */
404 #define MMF_DUMPABLE      0  /* core dump is permitted */
405 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
406 
407 #define MMF_DUMPABLE_BITS 2
408 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
409 
410 /* coredump filter bits */
411 #define MMF_DUMP_ANON_PRIVATE	2
412 #define MMF_DUMP_ANON_SHARED	3
413 #define MMF_DUMP_MAPPED_PRIVATE	4
414 #define MMF_DUMP_MAPPED_SHARED	5
415 #define MMF_DUMP_ELF_HEADERS	6
416 #define MMF_DUMP_HUGETLB_PRIVATE 7
417 #define MMF_DUMP_HUGETLB_SHARED  8
418 
419 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
420 #define MMF_DUMP_FILTER_BITS	7
421 #define MMF_DUMP_FILTER_MASK \
422 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
423 #define MMF_DUMP_FILTER_DEFAULT \
424 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
425 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
426 
427 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
428 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
429 #else
430 # define MMF_DUMP_MASK_DEFAULT_ELF	0
431 #endif
432 					/* leave room for more dump flags */
433 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
434 
435 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
436 
437 struct sighand_struct {
438 	atomic_t		count;
439 	struct k_sigaction	action[_NSIG];
440 	spinlock_t		siglock;
441 	wait_queue_head_t	signalfd_wqh;
442 };
443 
444 struct pacct_struct {
445 	int			ac_flag;
446 	long			ac_exitcode;
447 	unsigned long		ac_mem;
448 	cputime_t		ac_utime, ac_stime;
449 	unsigned long		ac_minflt, ac_majflt;
450 };
451 
452 struct cpu_itimer {
453 	cputime_t expires;
454 	cputime_t incr;
455 	u32 error;
456 	u32 incr_error;
457 };
458 
459 /**
460  * struct task_cputime - collected CPU time counts
461  * @utime:		time spent in user mode, in &cputime_t units
462  * @stime:		time spent in kernel mode, in &cputime_t units
463  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
464  *
465  * This structure groups together three kinds of CPU time that are
466  * tracked for threads and thread groups.  Most things considering
467  * CPU time want to group these counts together and treat all three
468  * of them in parallel.
469  */
470 struct task_cputime {
471 	cputime_t utime;
472 	cputime_t stime;
473 	unsigned long long sum_exec_runtime;
474 };
475 /* Alternate field names when used to cache expirations. */
476 #define prof_exp	stime
477 #define virt_exp	utime
478 #define sched_exp	sum_exec_runtime
479 
480 #define INIT_CPUTIME	\
481 	(struct task_cputime) {					\
482 		.utime = cputime_zero,				\
483 		.stime = cputime_zero,				\
484 		.sum_exec_runtime = 0,				\
485 	}
486 
487 /*
488  * Disable preemption until the scheduler is running.
489  * Reset by start_kernel()->sched_init()->init_idle().
490  *
491  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
492  * before the scheduler is active -- see should_resched().
493  */
494 #define INIT_PREEMPT_COUNT	(1 + PREEMPT_ACTIVE)
495 
496 /**
497  * struct thread_group_cputimer - thread group interval timer counts
498  * @cputime:		thread group interval timers.
499  * @running:		non-zero when there are timers running and
500  * 			@cputime receives updates.
501  * @lock:		lock for fields in this struct.
502  *
503  * This structure contains the version of task_cputime, above, that is
504  * used for thread group CPU timer calculations.
505  */
506 struct thread_group_cputimer {
507 	struct task_cputime cputime;
508 	int running;
509 	spinlock_t lock;
510 };
511 
512 /*
513  * NOTE! "signal_struct" does not have it's own
514  * locking, because a shared signal_struct always
515  * implies a shared sighand_struct, so locking
516  * sighand_struct is always a proper superset of
517  * the locking of signal_struct.
518  */
519 struct signal_struct {
520 	atomic_t		sigcnt;
521 	atomic_t		live;
522 	int			nr_threads;
523 
524 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
525 
526 	/* current thread group signal load-balancing target: */
527 	struct task_struct	*curr_target;
528 
529 	/* shared signal handling: */
530 	struct sigpending	shared_pending;
531 
532 	/* thread group exit support */
533 	int			group_exit_code;
534 	/* overloaded:
535 	 * - notify group_exit_task when ->count is equal to notify_count
536 	 * - everyone except group_exit_task is stopped during signal delivery
537 	 *   of fatal signals, group_exit_task processes the signal.
538 	 */
539 	int			notify_count;
540 	struct task_struct	*group_exit_task;
541 
542 	/* thread group stop support, overloads group_exit_code too */
543 	int			group_stop_count;
544 	unsigned int		flags; /* see SIGNAL_* flags below */
545 
546 	/* POSIX.1b Interval Timers */
547 	struct list_head posix_timers;
548 
549 	/* ITIMER_REAL timer for the process */
550 	struct hrtimer real_timer;
551 	struct pid *leader_pid;
552 	ktime_t it_real_incr;
553 
554 	/*
555 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
556 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
557 	 * values are defined to 0 and 1 respectively
558 	 */
559 	struct cpu_itimer it[2];
560 
561 	/*
562 	 * Thread group totals for process CPU timers.
563 	 * See thread_group_cputimer(), et al, for details.
564 	 */
565 	struct thread_group_cputimer cputimer;
566 
567 	/* Earliest-expiration cache. */
568 	struct task_cputime cputime_expires;
569 
570 	struct list_head cpu_timers[3];
571 
572 	struct pid *tty_old_pgrp;
573 
574 	/* boolean value for session group leader */
575 	int leader;
576 
577 	struct tty_struct *tty; /* NULL if no tty */
578 
579 	/*
580 	 * Cumulative resource counters for dead threads in the group,
581 	 * and for reaped dead child processes forked by this group.
582 	 * Live threads maintain their own counters and add to these
583 	 * in __exit_signal, except for the group leader.
584 	 */
585 	cputime_t utime, stime, cutime, cstime;
586 	cputime_t gtime;
587 	cputime_t cgtime;
588 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
589 	cputime_t prev_utime, prev_stime;
590 #endif
591 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
592 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
593 	unsigned long inblock, oublock, cinblock, coublock;
594 	unsigned long maxrss, cmaxrss;
595 	struct task_io_accounting ioac;
596 
597 	/*
598 	 * Cumulative ns of schedule CPU time fo dead threads in the
599 	 * group, not including a zombie group leader, (This only differs
600 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
601 	 * other than jiffies.)
602 	 */
603 	unsigned long long sum_sched_runtime;
604 
605 	/*
606 	 * We don't bother to synchronize most readers of this at all,
607 	 * because there is no reader checking a limit that actually needs
608 	 * to get both rlim_cur and rlim_max atomically, and either one
609 	 * alone is a single word that can safely be read normally.
610 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
611 	 * protect this instead of the siglock, because they really
612 	 * have no need to disable irqs.
613 	 */
614 	struct rlimit rlim[RLIM_NLIMITS];
615 
616 #ifdef CONFIG_BSD_PROCESS_ACCT
617 	struct pacct_struct pacct;	/* per-process accounting information */
618 #endif
619 #ifdef CONFIG_TASKSTATS
620 	struct taskstats *stats;
621 #endif
622 #ifdef CONFIG_AUDIT
623 	unsigned audit_tty;
624 	struct tty_audit_buf *tty_audit_buf;
625 #endif
626 
627 	int oom_adj;		/* OOM kill score adjustment (bit shift) */
628 	int oom_score_adj;	/* OOM kill score adjustment */
629 
630 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
631 					 * credential calculations
632 					 * (notably. ptrace) */
633 };
634 
635 /* Context switch must be unlocked if interrupts are to be enabled */
636 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
637 # define __ARCH_WANT_UNLOCKED_CTXSW
638 #endif
639 
640 /*
641  * Bits in flags field of signal_struct.
642  */
643 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
644 #define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
645 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
646 #define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
647 /*
648  * Pending notifications to parent.
649  */
650 #define SIGNAL_CLD_STOPPED	0x00000010
651 #define SIGNAL_CLD_CONTINUED	0x00000020
652 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
653 
654 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
655 
656 /* If true, all threads except ->group_exit_task have pending SIGKILL */
657 static inline int signal_group_exit(const struct signal_struct *sig)
658 {
659 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
660 		(sig->group_exit_task != NULL);
661 }
662 
663 /*
664  * Some day this will be a full-fledged user tracking system..
665  */
666 struct user_struct {
667 	atomic_t __count;	/* reference count */
668 	atomic_t processes;	/* How many processes does this user have? */
669 	atomic_t files;		/* How many open files does this user have? */
670 	atomic_t sigpending;	/* How many pending signals does this user have? */
671 #ifdef CONFIG_INOTIFY_USER
672 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
673 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
674 #endif
675 #ifdef CONFIG_FANOTIFY
676 	atomic_t fanotify_listeners;
677 #endif
678 #ifdef CONFIG_EPOLL
679 	atomic_t epoll_watches;	/* The number of file descriptors currently watched */
680 #endif
681 #ifdef CONFIG_POSIX_MQUEUE
682 	/* protected by mq_lock	*/
683 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
684 #endif
685 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
686 
687 #ifdef CONFIG_KEYS
688 	struct key *uid_keyring;	/* UID specific keyring */
689 	struct key *session_keyring;	/* UID's default session keyring */
690 #endif
691 
692 	/* Hash table maintenance information */
693 	struct hlist_node uidhash_node;
694 	uid_t uid;
695 	struct user_namespace *user_ns;
696 
697 #ifdef CONFIG_PERF_EVENTS
698 	atomic_long_t locked_vm;
699 #endif
700 };
701 
702 extern int uids_sysfs_init(void);
703 
704 extern struct user_struct *find_user(uid_t);
705 
706 extern struct user_struct root_user;
707 #define INIT_USER (&root_user)
708 
709 
710 struct backing_dev_info;
711 struct reclaim_state;
712 
713 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
714 struct sched_info {
715 	/* cumulative counters */
716 	unsigned long pcount;	      /* # of times run on this cpu */
717 	unsigned long long run_delay; /* time spent waiting on a runqueue */
718 
719 	/* timestamps */
720 	unsigned long long last_arrival,/* when we last ran on a cpu */
721 			   last_queued;	/* when we were last queued to run */
722 #ifdef CONFIG_SCHEDSTATS
723 	/* BKL stats */
724 	unsigned int bkl_count;
725 #endif
726 };
727 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
728 
729 #ifdef CONFIG_TASK_DELAY_ACCT
730 struct task_delay_info {
731 	spinlock_t	lock;
732 	unsigned int	flags;	/* Private per-task flags */
733 
734 	/* For each stat XXX, add following, aligned appropriately
735 	 *
736 	 * struct timespec XXX_start, XXX_end;
737 	 * u64 XXX_delay;
738 	 * u32 XXX_count;
739 	 *
740 	 * Atomicity of updates to XXX_delay, XXX_count protected by
741 	 * single lock above (split into XXX_lock if contention is an issue).
742 	 */
743 
744 	/*
745 	 * XXX_count is incremented on every XXX operation, the delay
746 	 * associated with the operation is added to XXX_delay.
747 	 * XXX_delay contains the accumulated delay time in nanoseconds.
748 	 */
749 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
750 	u64 blkio_delay;	/* wait for sync block io completion */
751 	u64 swapin_delay;	/* wait for swapin block io completion */
752 	u32 blkio_count;	/* total count of the number of sync block */
753 				/* io operations performed */
754 	u32 swapin_count;	/* total count of the number of swapin block */
755 				/* io operations performed */
756 
757 	struct timespec freepages_start, freepages_end;
758 	u64 freepages_delay;	/* wait for memory reclaim */
759 	u32 freepages_count;	/* total count of memory reclaim */
760 };
761 #endif	/* CONFIG_TASK_DELAY_ACCT */
762 
763 static inline int sched_info_on(void)
764 {
765 #ifdef CONFIG_SCHEDSTATS
766 	return 1;
767 #elif defined(CONFIG_TASK_DELAY_ACCT)
768 	extern int delayacct_on;
769 	return delayacct_on;
770 #else
771 	return 0;
772 #endif
773 }
774 
775 enum cpu_idle_type {
776 	CPU_IDLE,
777 	CPU_NOT_IDLE,
778 	CPU_NEWLY_IDLE,
779 	CPU_MAX_IDLE_TYPES
780 };
781 
782 /*
783  * sched-domains (multiprocessor balancing) declarations:
784  */
785 
786 /*
787  * Increase resolution of nice-level calculations:
788  */
789 #define SCHED_LOAD_SHIFT	10
790 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
791 
792 #define SCHED_LOAD_SCALE_FUZZ	SCHED_LOAD_SCALE
793 
794 #ifdef CONFIG_SMP
795 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
796 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
797 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
798 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
799 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
800 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
801 #define SD_PREFER_LOCAL		0x0040  /* Prefer to keep tasks local to this domain */
802 #define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
803 #define SD_POWERSAVINGS_BALANCE	0x0100	/* Balance for power savings */
804 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
805 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
806 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
807 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
808 
809 enum powersavings_balance_level {
810 	POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
811 	POWERSAVINGS_BALANCE_BASIC,	/* Fill one thread/core/package
812 					 * first for long running threads
813 					 */
814 	POWERSAVINGS_BALANCE_WAKEUP,	/* Also bias task wakeups to semi-idle
815 					 * cpu package for power savings
816 					 */
817 	MAX_POWERSAVINGS_BALANCE_LEVELS
818 };
819 
820 extern int sched_mc_power_savings, sched_smt_power_savings;
821 
822 static inline int sd_balance_for_mc_power(void)
823 {
824 	if (sched_smt_power_savings)
825 		return SD_POWERSAVINGS_BALANCE;
826 
827 	if (!sched_mc_power_savings)
828 		return SD_PREFER_SIBLING;
829 
830 	return 0;
831 }
832 
833 static inline int sd_balance_for_package_power(void)
834 {
835 	if (sched_mc_power_savings | sched_smt_power_savings)
836 		return SD_POWERSAVINGS_BALANCE;
837 
838 	return SD_PREFER_SIBLING;
839 }
840 
841 extern int __weak arch_sd_sibiling_asym_packing(void);
842 
843 /*
844  * Optimise SD flags for power savings:
845  * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings.
846  * Keep default SD flags if sched_{smt,mc}_power_saving=0
847  */
848 
849 static inline int sd_power_saving_flags(void)
850 {
851 	if (sched_mc_power_savings | sched_smt_power_savings)
852 		return SD_BALANCE_NEWIDLE;
853 
854 	return 0;
855 }
856 
857 struct sched_group {
858 	struct sched_group *next;	/* Must be a circular list */
859 
860 	/*
861 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
862 	 * single CPU.
863 	 */
864 	unsigned int cpu_power, cpu_power_orig;
865 	unsigned int group_weight;
866 
867 	/*
868 	 * The CPUs this group covers.
869 	 *
870 	 * NOTE: this field is variable length. (Allocated dynamically
871 	 * by attaching extra space to the end of the structure,
872 	 * depending on how many CPUs the kernel has booted up with)
873 	 *
874 	 * It is also be embedded into static data structures at build
875 	 * time. (See 'struct static_sched_group' in kernel/sched.c)
876 	 */
877 	unsigned long cpumask[0];
878 };
879 
880 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
881 {
882 	return to_cpumask(sg->cpumask);
883 }
884 
885 enum sched_domain_level {
886 	SD_LV_NONE = 0,
887 	SD_LV_SIBLING,
888 	SD_LV_MC,
889 	SD_LV_BOOK,
890 	SD_LV_CPU,
891 	SD_LV_NODE,
892 	SD_LV_ALLNODES,
893 	SD_LV_MAX
894 };
895 
896 struct sched_domain_attr {
897 	int relax_domain_level;
898 };
899 
900 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
901 	.relax_domain_level = -1,			\
902 }
903 
904 struct sched_domain {
905 	/* These fields must be setup */
906 	struct sched_domain *parent;	/* top domain must be null terminated */
907 	struct sched_domain *child;	/* bottom domain must be null terminated */
908 	struct sched_group *groups;	/* the balancing groups of the domain */
909 	unsigned long min_interval;	/* Minimum balance interval ms */
910 	unsigned long max_interval;	/* Maximum balance interval ms */
911 	unsigned int busy_factor;	/* less balancing by factor if busy */
912 	unsigned int imbalance_pct;	/* No balance until over watermark */
913 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
914 	unsigned int busy_idx;
915 	unsigned int idle_idx;
916 	unsigned int newidle_idx;
917 	unsigned int wake_idx;
918 	unsigned int forkexec_idx;
919 	unsigned int smt_gain;
920 	int flags;			/* See SD_* */
921 	enum sched_domain_level level;
922 
923 	/* Runtime fields. */
924 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
925 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
926 	unsigned int nr_balance_failed; /* initialise to 0 */
927 
928 	u64 last_update;
929 
930 #ifdef CONFIG_SCHEDSTATS
931 	/* load_balance() stats */
932 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
933 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
934 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
935 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
936 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
937 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
938 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
939 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
940 
941 	/* Active load balancing */
942 	unsigned int alb_count;
943 	unsigned int alb_failed;
944 	unsigned int alb_pushed;
945 
946 	/* SD_BALANCE_EXEC stats */
947 	unsigned int sbe_count;
948 	unsigned int sbe_balanced;
949 	unsigned int sbe_pushed;
950 
951 	/* SD_BALANCE_FORK stats */
952 	unsigned int sbf_count;
953 	unsigned int sbf_balanced;
954 	unsigned int sbf_pushed;
955 
956 	/* try_to_wake_up() stats */
957 	unsigned int ttwu_wake_remote;
958 	unsigned int ttwu_move_affine;
959 	unsigned int ttwu_move_balance;
960 #endif
961 #ifdef CONFIG_SCHED_DEBUG
962 	char *name;
963 #endif
964 
965 	unsigned int span_weight;
966 	/*
967 	 * Span of all CPUs in this domain.
968 	 *
969 	 * NOTE: this field is variable length. (Allocated dynamically
970 	 * by attaching extra space to the end of the structure,
971 	 * depending on how many CPUs the kernel has booted up with)
972 	 *
973 	 * It is also be embedded into static data structures at build
974 	 * time. (See 'struct static_sched_domain' in kernel/sched.c)
975 	 */
976 	unsigned long span[0];
977 };
978 
979 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
980 {
981 	return to_cpumask(sd->span);
982 }
983 
984 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
985 				    struct sched_domain_attr *dattr_new);
986 
987 /* Allocate an array of sched domains, for partition_sched_domains(). */
988 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
989 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
990 
991 /* Test a flag in parent sched domain */
992 static inline int test_sd_parent(struct sched_domain *sd, int flag)
993 {
994 	if (sd->parent && (sd->parent->flags & flag))
995 		return 1;
996 
997 	return 0;
998 }
999 
1000 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1001 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1002 
1003 #else /* CONFIG_SMP */
1004 
1005 struct sched_domain_attr;
1006 
1007 static inline void
1008 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1009 			struct sched_domain_attr *dattr_new)
1010 {
1011 }
1012 #endif	/* !CONFIG_SMP */
1013 
1014 
1015 struct io_context;			/* See blkdev.h */
1016 
1017 
1018 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1019 extern void prefetch_stack(struct task_struct *t);
1020 #else
1021 static inline void prefetch_stack(struct task_struct *t) { }
1022 #endif
1023 
1024 struct audit_context;		/* See audit.c */
1025 struct mempolicy;
1026 struct pipe_inode_info;
1027 struct uts_namespace;
1028 
1029 struct rq;
1030 struct sched_domain;
1031 
1032 /*
1033  * wake flags
1034  */
1035 #define WF_SYNC		0x01		/* waker goes to sleep after wakup */
1036 #define WF_FORK		0x02		/* child wakeup after fork */
1037 
1038 #define ENQUEUE_WAKEUP		1
1039 #define ENQUEUE_WAKING		2
1040 #define ENQUEUE_HEAD		4
1041 
1042 #define DEQUEUE_SLEEP		1
1043 
1044 struct sched_class {
1045 	const struct sched_class *next;
1046 
1047 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1048 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1049 	void (*yield_task) (struct rq *rq);
1050 
1051 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1052 
1053 	struct task_struct * (*pick_next_task) (struct rq *rq);
1054 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1055 
1056 #ifdef CONFIG_SMP
1057 	int  (*select_task_rq)(struct rq *rq, struct task_struct *p,
1058 			       int sd_flag, int flags);
1059 
1060 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1061 	void (*post_schedule) (struct rq *this_rq);
1062 	void (*task_waking) (struct rq *this_rq, struct task_struct *task);
1063 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1064 
1065 	void (*set_cpus_allowed)(struct task_struct *p,
1066 				 const struct cpumask *newmask);
1067 
1068 	void (*rq_online)(struct rq *rq);
1069 	void (*rq_offline)(struct rq *rq);
1070 #endif
1071 
1072 	void (*set_curr_task) (struct rq *rq);
1073 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1074 	void (*task_fork) (struct task_struct *p);
1075 
1076 	void (*switched_from) (struct rq *this_rq, struct task_struct *task,
1077 			       int running);
1078 	void (*switched_to) (struct rq *this_rq, struct task_struct *task,
1079 			     int running);
1080 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1081 			     int oldprio, int running);
1082 
1083 	unsigned int (*get_rr_interval) (struct rq *rq,
1084 					 struct task_struct *task);
1085 
1086 #ifdef CONFIG_FAIR_GROUP_SCHED
1087 	void (*task_move_group) (struct task_struct *p, int on_rq);
1088 #endif
1089 };
1090 
1091 struct load_weight {
1092 	unsigned long weight, inv_weight;
1093 };
1094 
1095 #ifdef CONFIG_SCHEDSTATS
1096 struct sched_statistics {
1097 	u64			wait_start;
1098 	u64			wait_max;
1099 	u64			wait_count;
1100 	u64			wait_sum;
1101 	u64			iowait_count;
1102 	u64			iowait_sum;
1103 
1104 	u64			sleep_start;
1105 	u64			sleep_max;
1106 	s64			sum_sleep_runtime;
1107 
1108 	u64			block_start;
1109 	u64			block_max;
1110 	u64			exec_max;
1111 	u64			slice_max;
1112 
1113 	u64			nr_migrations_cold;
1114 	u64			nr_failed_migrations_affine;
1115 	u64			nr_failed_migrations_running;
1116 	u64			nr_failed_migrations_hot;
1117 	u64			nr_forced_migrations;
1118 
1119 	u64			nr_wakeups;
1120 	u64			nr_wakeups_sync;
1121 	u64			nr_wakeups_migrate;
1122 	u64			nr_wakeups_local;
1123 	u64			nr_wakeups_remote;
1124 	u64			nr_wakeups_affine;
1125 	u64			nr_wakeups_affine_attempts;
1126 	u64			nr_wakeups_passive;
1127 	u64			nr_wakeups_idle;
1128 };
1129 #endif
1130 
1131 struct sched_entity {
1132 	struct load_weight	load;		/* for load-balancing */
1133 	struct rb_node		run_node;
1134 	struct list_head	group_node;
1135 	unsigned int		on_rq;
1136 
1137 	u64			exec_start;
1138 	u64			sum_exec_runtime;
1139 	u64			vruntime;
1140 	u64			prev_sum_exec_runtime;
1141 
1142 	u64			nr_migrations;
1143 
1144 #ifdef CONFIG_SCHEDSTATS
1145 	struct sched_statistics statistics;
1146 #endif
1147 
1148 #ifdef CONFIG_FAIR_GROUP_SCHED
1149 	struct sched_entity	*parent;
1150 	/* rq on which this entity is (to be) queued: */
1151 	struct cfs_rq		*cfs_rq;
1152 	/* rq "owned" by this entity/group: */
1153 	struct cfs_rq		*my_q;
1154 #endif
1155 };
1156 
1157 struct sched_rt_entity {
1158 	struct list_head run_list;
1159 	unsigned long timeout;
1160 	unsigned int time_slice;
1161 	int nr_cpus_allowed;
1162 
1163 	struct sched_rt_entity *back;
1164 #ifdef CONFIG_RT_GROUP_SCHED
1165 	struct sched_rt_entity	*parent;
1166 	/* rq on which this entity is (to be) queued: */
1167 	struct rt_rq		*rt_rq;
1168 	/* rq "owned" by this entity/group: */
1169 	struct rt_rq		*my_q;
1170 #endif
1171 };
1172 
1173 struct rcu_node;
1174 
1175 enum perf_event_task_context {
1176 	perf_invalid_context = -1,
1177 	perf_hw_context = 0,
1178 	perf_sw_context,
1179 	perf_nr_task_contexts,
1180 };
1181 
1182 struct task_struct {
1183 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1184 	void *stack;
1185 	atomic_t usage;
1186 	unsigned int flags;	/* per process flags, defined below */
1187 	unsigned int ptrace;
1188 
1189 	int lock_depth;		/* BKL lock depth */
1190 
1191 #ifdef CONFIG_SMP
1192 #ifdef __ARCH_WANT_UNLOCKED_CTXSW
1193 	int oncpu;
1194 #endif
1195 #endif
1196 
1197 	int prio, static_prio, normal_prio;
1198 	unsigned int rt_priority;
1199 	const struct sched_class *sched_class;
1200 	struct sched_entity se;
1201 	struct sched_rt_entity rt;
1202 
1203 #ifdef CONFIG_PREEMPT_NOTIFIERS
1204 	/* list of struct preempt_notifier: */
1205 	struct hlist_head preempt_notifiers;
1206 #endif
1207 
1208 	/*
1209 	 * fpu_counter contains the number of consecutive context switches
1210 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1211 	 * saving becomes unlazy to save the trap. This is an unsigned char
1212 	 * so that after 256 times the counter wraps and the behavior turns
1213 	 * lazy again; this to deal with bursty apps that only use FPU for
1214 	 * a short time
1215 	 */
1216 	unsigned char fpu_counter;
1217 #ifdef CONFIG_BLK_DEV_IO_TRACE
1218 	unsigned int btrace_seq;
1219 #endif
1220 
1221 	unsigned int policy;
1222 	cpumask_t cpus_allowed;
1223 
1224 #ifdef CONFIG_PREEMPT_RCU
1225 	int rcu_read_lock_nesting;
1226 	char rcu_read_unlock_special;
1227 	struct list_head rcu_node_entry;
1228 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1229 #ifdef CONFIG_TREE_PREEMPT_RCU
1230 	struct rcu_node *rcu_blocked_node;
1231 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1232 
1233 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1234 	struct sched_info sched_info;
1235 #endif
1236 
1237 	struct list_head tasks;
1238 	struct plist_node pushable_tasks;
1239 
1240 	struct mm_struct *mm, *active_mm;
1241 #if defined(SPLIT_RSS_COUNTING)
1242 	struct task_rss_stat	rss_stat;
1243 #endif
1244 /* task state */
1245 	int exit_state;
1246 	int exit_code, exit_signal;
1247 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1248 	/* ??? */
1249 	unsigned int personality;
1250 	unsigned did_exec:1;
1251 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1252 				 * execve */
1253 	unsigned in_iowait:1;
1254 
1255 
1256 	/* Revert to default priority/policy when forking */
1257 	unsigned sched_reset_on_fork:1;
1258 
1259 	pid_t pid;
1260 	pid_t tgid;
1261 
1262 #ifdef CONFIG_CC_STACKPROTECTOR
1263 	/* Canary value for the -fstack-protector gcc feature */
1264 	unsigned long stack_canary;
1265 #endif
1266 
1267 	/*
1268 	 * pointers to (original) parent process, youngest child, younger sibling,
1269 	 * older sibling, respectively.  (p->father can be replaced with
1270 	 * p->real_parent->pid)
1271 	 */
1272 	struct task_struct *real_parent; /* real parent process */
1273 	struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1274 	/*
1275 	 * children/sibling forms the list of my natural children
1276 	 */
1277 	struct list_head children;	/* list of my children */
1278 	struct list_head sibling;	/* linkage in my parent's children list */
1279 	struct task_struct *group_leader;	/* threadgroup leader */
1280 
1281 	/*
1282 	 * ptraced is the list of tasks this task is using ptrace on.
1283 	 * This includes both natural children and PTRACE_ATTACH targets.
1284 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1285 	 */
1286 	struct list_head ptraced;
1287 	struct list_head ptrace_entry;
1288 
1289 	/* PID/PID hash table linkage. */
1290 	struct pid_link pids[PIDTYPE_MAX];
1291 	struct list_head thread_group;
1292 
1293 	struct completion *vfork_done;		/* for vfork() */
1294 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1295 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1296 
1297 	cputime_t utime, stime, utimescaled, stimescaled;
1298 	cputime_t gtime;
1299 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1300 	cputime_t prev_utime, prev_stime;
1301 #endif
1302 	unsigned long nvcsw, nivcsw; /* context switch counts */
1303 	struct timespec start_time; 		/* monotonic time */
1304 	struct timespec real_start_time;	/* boot based time */
1305 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1306 	unsigned long min_flt, maj_flt;
1307 
1308 	struct task_cputime cputime_expires;
1309 	struct list_head cpu_timers[3];
1310 
1311 /* process credentials */
1312 	const struct cred __rcu *real_cred; /* objective and real subjective task
1313 					 * credentials (COW) */
1314 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1315 					 * credentials (COW) */
1316 	struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
1317 
1318 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1319 				     - access with [gs]et_task_comm (which lock
1320 				       it with task_lock())
1321 				     - initialized normally by setup_new_exec */
1322 /* file system info */
1323 	int link_count, total_link_count;
1324 #ifdef CONFIG_SYSVIPC
1325 /* ipc stuff */
1326 	struct sysv_sem sysvsem;
1327 #endif
1328 #ifdef CONFIG_DETECT_HUNG_TASK
1329 /* hung task detection */
1330 	unsigned long last_switch_count;
1331 #endif
1332 /* CPU-specific state of this task */
1333 	struct thread_struct thread;
1334 /* filesystem information */
1335 	struct fs_struct *fs;
1336 /* open file information */
1337 	struct files_struct *files;
1338 /* namespaces */
1339 	struct nsproxy *nsproxy;
1340 /* signal handlers */
1341 	struct signal_struct *signal;
1342 	struct sighand_struct *sighand;
1343 
1344 	sigset_t blocked, real_blocked;
1345 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1346 	struct sigpending pending;
1347 
1348 	unsigned long sas_ss_sp;
1349 	size_t sas_ss_size;
1350 	int (*notifier)(void *priv);
1351 	void *notifier_data;
1352 	sigset_t *notifier_mask;
1353 	struct audit_context *audit_context;
1354 #ifdef CONFIG_AUDITSYSCALL
1355 	uid_t loginuid;
1356 	unsigned int sessionid;
1357 #endif
1358 	seccomp_t seccomp;
1359 
1360 /* Thread group tracking */
1361    	u32 parent_exec_id;
1362    	u32 self_exec_id;
1363 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1364  * mempolicy */
1365 	spinlock_t alloc_lock;
1366 
1367 #ifdef CONFIG_GENERIC_HARDIRQS
1368 	/* IRQ handler threads */
1369 	struct irqaction *irqaction;
1370 #endif
1371 
1372 	/* Protection of the PI data structures: */
1373 	raw_spinlock_t pi_lock;
1374 
1375 #ifdef CONFIG_RT_MUTEXES
1376 	/* PI waiters blocked on a rt_mutex held by this task */
1377 	struct plist_head pi_waiters;
1378 	/* Deadlock detection and priority inheritance handling */
1379 	struct rt_mutex_waiter *pi_blocked_on;
1380 #endif
1381 
1382 #ifdef CONFIG_DEBUG_MUTEXES
1383 	/* mutex deadlock detection */
1384 	struct mutex_waiter *blocked_on;
1385 #endif
1386 #ifdef CONFIG_TRACE_IRQFLAGS
1387 	unsigned int irq_events;
1388 	unsigned long hardirq_enable_ip;
1389 	unsigned long hardirq_disable_ip;
1390 	unsigned int hardirq_enable_event;
1391 	unsigned int hardirq_disable_event;
1392 	int hardirqs_enabled;
1393 	int hardirq_context;
1394 	unsigned long softirq_disable_ip;
1395 	unsigned long softirq_enable_ip;
1396 	unsigned int softirq_disable_event;
1397 	unsigned int softirq_enable_event;
1398 	int softirqs_enabled;
1399 	int softirq_context;
1400 #endif
1401 #ifdef CONFIG_LOCKDEP
1402 # define MAX_LOCK_DEPTH 48UL
1403 	u64 curr_chain_key;
1404 	int lockdep_depth;
1405 	unsigned int lockdep_recursion;
1406 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1407 	gfp_t lockdep_reclaim_gfp;
1408 #endif
1409 
1410 /* journalling filesystem info */
1411 	void *journal_info;
1412 
1413 /* stacked block device info */
1414 	struct bio_list *bio_list;
1415 
1416 /* VM state */
1417 	struct reclaim_state *reclaim_state;
1418 
1419 	struct backing_dev_info *backing_dev_info;
1420 
1421 	struct io_context *io_context;
1422 
1423 	unsigned long ptrace_message;
1424 	siginfo_t *last_siginfo; /* For ptrace use.  */
1425 	struct task_io_accounting ioac;
1426 #if defined(CONFIG_TASK_XACCT)
1427 	u64 acct_rss_mem1;	/* accumulated rss usage */
1428 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1429 	cputime_t acct_timexpd;	/* stime + utime since last update */
1430 #endif
1431 #ifdef CONFIG_CPUSETS
1432 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1433 	int mems_allowed_change_disable;
1434 	int cpuset_mem_spread_rotor;
1435 	int cpuset_slab_spread_rotor;
1436 #endif
1437 #ifdef CONFIG_CGROUPS
1438 	/* Control Group info protected by css_set_lock */
1439 	struct css_set __rcu *cgroups;
1440 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1441 	struct list_head cg_list;
1442 #endif
1443 #ifdef CONFIG_FUTEX
1444 	struct robust_list_head __user *robust_list;
1445 #ifdef CONFIG_COMPAT
1446 	struct compat_robust_list_head __user *compat_robust_list;
1447 #endif
1448 	struct list_head pi_state_list;
1449 	struct futex_pi_state *pi_state_cache;
1450 #endif
1451 #ifdef CONFIG_PERF_EVENTS
1452 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1453 	struct mutex perf_event_mutex;
1454 	struct list_head perf_event_list;
1455 #endif
1456 #ifdef CONFIG_NUMA
1457 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1458 	short il_next;
1459 #endif
1460 	atomic_t fs_excl;	/* holding fs exclusive resources */
1461 	struct rcu_head rcu;
1462 
1463 	/*
1464 	 * cache last used pipe for splice
1465 	 */
1466 	struct pipe_inode_info *splice_pipe;
1467 #ifdef	CONFIG_TASK_DELAY_ACCT
1468 	struct task_delay_info *delays;
1469 #endif
1470 #ifdef CONFIG_FAULT_INJECTION
1471 	int make_it_fail;
1472 #endif
1473 	struct prop_local_single dirties;
1474 #ifdef CONFIG_LATENCYTOP
1475 	int latency_record_count;
1476 	struct latency_record latency_record[LT_SAVECOUNT];
1477 #endif
1478 	/*
1479 	 * time slack values; these are used to round up poll() and
1480 	 * select() etc timeout values. These are in nanoseconds.
1481 	 */
1482 	unsigned long timer_slack_ns;
1483 	unsigned long default_timer_slack_ns;
1484 
1485 	struct list_head	*scm_work_list;
1486 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1487 	/* Index of current stored address in ret_stack */
1488 	int curr_ret_stack;
1489 	/* Stack of return addresses for return function tracing */
1490 	struct ftrace_ret_stack	*ret_stack;
1491 	/* time stamp for last schedule */
1492 	unsigned long long ftrace_timestamp;
1493 	/*
1494 	 * Number of functions that haven't been traced
1495 	 * because of depth overrun.
1496 	 */
1497 	atomic_t trace_overrun;
1498 	/* Pause for the tracing */
1499 	atomic_t tracing_graph_pause;
1500 #endif
1501 #ifdef CONFIG_TRACING
1502 	/* state flags for use by tracers */
1503 	unsigned long trace;
1504 	/* bitmask of trace recursion */
1505 	unsigned long trace_recursion;
1506 #endif /* CONFIG_TRACING */
1507 #ifdef CONFIG_CGROUP_MEM_RES_CTLR /* memcg uses this to do batch job */
1508 	struct memcg_batch_info {
1509 		int do_batch;	/* incremented when batch uncharge started */
1510 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1511 		unsigned long bytes; 		/* uncharged usage */
1512 		unsigned long memsw_bytes; /* uncharged mem+swap usage */
1513 	} memcg_batch;
1514 #endif
1515 };
1516 
1517 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1518 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1519 
1520 /*
1521  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1522  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1523  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1524  * values are inverted: lower p->prio value means higher priority.
1525  *
1526  * The MAX_USER_RT_PRIO value allows the actual maximum
1527  * RT priority to be separate from the value exported to
1528  * user-space.  This allows kernel threads to set their
1529  * priority to a value higher than any user task. Note:
1530  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1531  */
1532 
1533 #define MAX_USER_RT_PRIO	100
1534 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1535 
1536 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1537 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1538 
1539 static inline int rt_prio(int prio)
1540 {
1541 	if (unlikely(prio < MAX_RT_PRIO))
1542 		return 1;
1543 	return 0;
1544 }
1545 
1546 static inline int rt_task(struct task_struct *p)
1547 {
1548 	return rt_prio(p->prio);
1549 }
1550 
1551 static inline struct pid *task_pid(struct task_struct *task)
1552 {
1553 	return task->pids[PIDTYPE_PID].pid;
1554 }
1555 
1556 static inline struct pid *task_tgid(struct task_struct *task)
1557 {
1558 	return task->group_leader->pids[PIDTYPE_PID].pid;
1559 }
1560 
1561 /*
1562  * Without tasklist or rcu lock it is not safe to dereference
1563  * the result of task_pgrp/task_session even if task == current,
1564  * we can race with another thread doing sys_setsid/sys_setpgid.
1565  */
1566 static inline struct pid *task_pgrp(struct task_struct *task)
1567 {
1568 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1569 }
1570 
1571 static inline struct pid *task_session(struct task_struct *task)
1572 {
1573 	return task->group_leader->pids[PIDTYPE_SID].pid;
1574 }
1575 
1576 struct pid_namespace;
1577 
1578 /*
1579  * the helpers to get the task's different pids as they are seen
1580  * from various namespaces
1581  *
1582  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1583  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1584  *                     current.
1585  * task_xid_nr_ns()  : id seen from the ns specified;
1586  *
1587  * set_task_vxid()   : assigns a virtual id to a task;
1588  *
1589  * see also pid_nr() etc in include/linux/pid.h
1590  */
1591 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1592 			struct pid_namespace *ns);
1593 
1594 static inline pid_t task_pid_nr(struct task_struct *tsk)
1595 {
1596 	return tsk->pid;
1597 }
1598 
1599 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1600 					struct pid_namespace *ns)
1601 {
1602 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1603 }
1604 
1605 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1606 {
1607 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1608 }
1609 
1610 
1611 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1612 {
1613 	return tsk->tgid;
1614 }
1615 
1616 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1617 
1618 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1619 {
1620 	return pid_vnr(task_tgid(tsk));
1621 }
1622 
1623 
1624 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1625 					struct pid_namespace *ns)
1626 {
1627 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1628 }
1629 
1630 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1631 {
1632 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1633 }
1634 
1635 
1636 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1637 					struct pid_namespace *ns)
1638 {
1639 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1640 }
1641 
1642 static inline pid_t task_session_vnr(struct task_struct *tsk)
1643 {
1644 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1645 }
1646 
1647 /* obsolete, do not use */
1648 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1649 {
1650 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1651 }
1652 
1653 /**
1654  * pid_alive - check that a task structure is not stale
1655  * @p: Task structure to be checked.
1656  *
1657  * Test if a process is not yet dead (at most zombie state)
1658  * If pid_alive fails, then pointers within the task structure
1659  * can be stale and must not be dereferenced.
1660  */
1661 static inline int pid_alive(struct task_struct *p)
1662 {
1663 	return p->pids[PIDTYPE_PID].pid != NULL;
1664 }
1665 
1666 /**
1667  * is_global_init - check if a task structure is init
1668  * @tsk: Task structure to be checked.
1669  *
1670  * Check if a task structure is the first user space task the kernel created.
1671  */
1672 static inline int is_global_init(struct task_struct *tsk)
1673 {
1674 	return tsk->pid == 1;
1675 }
1676 
1677 /*
1678  * is_container_init:
1679  * check whether in the task is init in its own pid namespace.
1680  */
1681 extern int is_container_init(struct task_struct *tsk);
1682 
1683 extern struct pid *cad_pid;
1684 
1685 extern void free_task(struct task_struct *tsk);
1686 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1687 
1688 extern void __put_task_struct(struct task_struct *t);
1689 
1690 static inline void put_task_struct(struct task_struct *t)
1691 {
1692 	if (atomic_dec_and_test(&t->usage))
1693 		__put_task_struct(t);
1694 }
1695 
1696 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1697 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1698 
1699 /*
1700  * Per process flags
1701  */
1702 #define PF_KSOFTIRQD	0x00000001	/* I am ksoftirqd */
1703 #define PF_STARTING	0x00000002	/* being created */
1704 #define PF_EXITING	0x00000004	/* getting shut down */
1705 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1706 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1707 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1708 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1709 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1710 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1711 #define PF_DUMPCORE	0x00000200	/* dumped core */
1712 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1713 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1714 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1715 #define PF_FREEZING	0x00004000	/* freeze in progress. do not account to load */
1716 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1717 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1718 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1719 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1720 #define PF_OOM_ORIGIN	0x00080000	/* Allocating much memory to others */
1721 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1722 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1723 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1724 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1725 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1726 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1727 #define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1728 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1729 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1730 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1731 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezeable */
1732 #define PF_FREEZER_NOSIG 0x80000000	/* Freezer won't send signals to it */
1733 
1734 /*
1735  * Only the _current_ task can read/write to tsk->flags, but other
1736  * tasks can access tsk->flags in readonly mode for example
1737  * with tsk_used_math (like during threaded core dumping).
1738  * There is however an exception to this rule during ptrace
1739  * or during fork: the ptracer task is allowed to write to the
1740  * child->flags of its traced child (same goes for fork, the parent
1741  * can write to the child->flags), because we're guaranteed the
1742  * child is not running and in turn not changing child->flags
1743  * at the same time the parent does it.
1744  */
1745 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1746 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1747 #define clear_used_math() clear_stopped_child_used_math(current)
1748 #define set_used_math() set_stopped_child_used_math(current)
1749 #define conditional_stopped_child_used_math(condition, child) \
1750 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1751 #define conditional_used_math(condition) \
1752 	conditional_stopped_child_used_math(condition, current)
1753 #define copy_to_stopped_child_used_math(child) \
1754 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1755 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1756 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1757 #define used_math() tsk_used_math(current)
1758 
1759 #ifdef CONFIG_PREEMPT_RCU
1760 
1761 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1762 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1763 
1764 static inline void rcu_copy_process(struct task_struct *p)
1765 {
1766 	p->rcu_read_lock_nesting = 0;
1767 	p->rcu_read_unlock_special = 0;
1768 #ifdef CONFIG_TREE_PREEMPT_RCU
1769 	p->rcu_blocked_node = NULL;
1770 #endif
1771 	INIT_LIST_HEAD(&p->rcu_node_entry);
1772 }
1773 
1774 #else
1775 
1776 static inline void rcu_copy_process(struct task_struct *p)
1777 {
1778 }
1779 
1780 #endif
1781 
1782 #ifdef CONFIG_SMP
1783 extern int set_cpus_allowed_ptr(struct task_struct *p,
1784 				const struct cpumask *new_mask);
1785 #else
1786 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1787 				       const struct cpumask *new_mask)
1788 {
1789 	if (!cpumask_test_cpu(0, new_mask))
1790 		return -EINVAL;
1791 	return 0;
1792 }
1793 #endif
1794 
1795 #ifndef CONFIG_CPUMASK_OFFSTACK
1796 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1797 {
1798 	return set_cpus_allowed_ptr(p, &new_mask);
1799 }
1800 #endif
1801 
1802 /*
1803  * Do not use outside of architecture code which knows its limitations.
1804  *
1805  * sched_clock() has no promise of monotonicity or bounded drift between
1806  * CPUs, use (which you should not) requires disabling IRQs.
1807  *
1808  * Please use one of the three interfaces below.
1809  */
1810 extern unsigned long long notrace sched_clock(void);
1811 /*
1812  * See the comment in kernel/sched_clock.c
1813  */
1814 extern u64 cpu_clock(int cpu);
1815 extern u64 local_clock(void);
1816 extern u64 sched_clock_cpu(int cpu);
1817 
1818 
1819 extern void sched_clock_init(void);
1820 
1821 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1822 static inline void sched_clock_tick(void)
1823 {
1824 }
1825 
1826 static inline void sched_clock_idle_sleep_event(void)
1827 {
1828 }
1829 
1830 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1831 {
1832 }
1833 #else
1834 /*
1835  * Architectures can set this to 1 if they have specified
1836  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1837  * but then during bootup it turns out that sched_clock()
1838  * is reliable after all:
1839  */
1840 extern int sched_clock_stable;
1841 
1842 extern void sched_clock_tick(void);
1843 extern void sched_clock_idle_sleep_event(void);
1844 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1845 #endif
1846 
1847 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1848 /*
1849  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1850  * The reason for this explicit opt-in is not to have perf penalty with
1851  * slow sched_clocks.
1852  */
1853 extern void enable_sched_clock_irqtime(void);
1854 extern void disable_sched_clock_irqtime(void);
1855 #else
1856 static inline void enable_sched_clock_irqtime(void) {}
1857 static inline void disable_sched_clock_irqtime(void) {}
1858 #endif
1859 
1860 extern unsigned long long
1861 task_sched_runtime(struct task_struct *task);
1862 extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
1863 
1864 /* sched_exec is called by processes performing an exec */
1865 #ifdef CONFIG_SMP
1866 extern void sched_exec(void);
1867 #else
1868 #define sched_exec()   {}
1869 #endif
1870 
1871 extern void sched_clock_idle_sleep_event(void);
1872 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1873 
1874 #ifdef CONFIG_HOTPLUG_CPU
1875 extern void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p);
1876 extern void idle_task_exit(void);
1877 #else
1878 static inline void idle_task_exit(void) {}
1879 #endif
1880 
1881 extern void sched_idle_next(void);
1882 
1883 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1884 extern void wake_up_idle_cpu(int cpu);
1885 #else
1886 static inline void wake_up_idle_cpu(int cpu) { }
1887 #endif
1888 
1889 extern unsigned int sysctl_sched_latency;
1890 extern unsigned int sysctl_sched_min_granularity;
1891 extern unsigned int sysctl_sched_wakeup_granularity;
1892 extern unsigned int sysctl_sched_shares_ratelimit;
1893 extern unsigned int sysctl_sched_shares_thresh;
1894 extern unsigned int sysctl_sched_child_runs_first;
1895 
1896 enum sched_tunable_scaling {
1897 	SCHED_TUNABLESCALING_NONE,
1898 	SCHED_TUNABLESCALING_LOG,
1899 	SCHED_TUNABLESCALING_LINEAR,
1900 	SCHED_TUNABLESCALING_END,
1901 };
1902 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
1903 
1904 #ifdef CONFIG_SCHED_DEBUG
1905 extern unsigned int sysctl_sched_migration_cost;
1906 extern unsigned int sysctl_sched_nr_migrate;
1907 extern unsigned int sysctl_sched_time_avg;
1908 extern unsigned int sysctl_timer_migration;
1909 
1910 int sched_proc_update_handler(struct ctl_table *table, int write,
1911 		void __user *buffer, size_t *length,
1912 		loff_t *ppos);
1913 #endif
1914 #ifdef CONFIG_SCHED_DEBUG
1915 static inline unsigned int get_sysctl_timer_migration(void)
1916 {
1917 	return sysctl_timer_migration;
1918 }
1919 #else
1920 static inline unsigned int get_sysctl_timer_migration(void)
1921 {
1922 	return 1;
1923 }
1924 #endif
1925 extern unsigned int sysctl_sched_rt_period;
1926 extern int sysctl_sched_rt_runtime;
1927 
1928 int sched_rt_handler(struct ctl_table *table, int write,
1929 		void __user *buffer, size_t *lenp,
1930 		loff_t *ppos);
1931 
1932 extern unsigned int sysctl_sched_compat_yield;
1933 
1934 #ifdef CONFIG_RT_MUTEXES
1935 extern int rt_mutex_getprio(struct task_struct *p);
1936 extern void rt_mutex_setprio(struct task_struct *p, int prio);
1937 extern void rt_mutex_adjust_pi(struct task_struct *p);
1938 #else
1939 static inline int rt_mutex_getprio(struct task_struct *p)
1940 {
1941 	return p->normal_prio;
1942 }
1943 # define rt_mutex_adjust_pi(p)		do { } while (0)
1944 #endif
1945 
1946 extern void set_user_nice(struct task_struct *p, long nice);
1947 extern int task_prio(const struct task_struct *p);
1948 extern int task_nice(const struct task_struct *p);
1949 extern int can_nice(const struct task_struct *p, const int nice);
1950 extern int task_curr(const struct task_struct *p);
1951 extern int idle_cpu(int cpu);
1952 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1953 extern int sched_setscheduler_nocheck(struct task_struct *, int,
1954 				      struct sched_param *);
1955 extern struct task_struct *idle_task(int cpu);
1956 extern struct task_struct *curr_task(int cpu);
1957 extern void set_curr_task(int cpu, struct task_struct *p);
1958 
1959 void yield(void);
1960 
1961 /*
1962  * The default (Linux) execution domain.
1963  */
1964 extern struct exec_domain	default_exec_domain;
1965 
1966 union thread_union {
1967 	struct thread_info thread_info;
1968 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1969 };
1970 
1971 #ifndef __HAVE_ARCH_KSTACK_END
1972 static inline int kstack_end(void *addr)
1973 {
1974 	/* Reliable end of stack detection:
1975 	 * Some APM bios versions misalign the stack
1976 	 */
1977 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1978 }
1979 #endif
1980 
1981 extern union thread_union init_thread_union;
1982 extern struct task_struct init_task;
1983 
1984 extern struct   mm_struct init_mm;
1985 
1986 extern struct pid_namespace init_pid_ns;
1987 
1988 /*
1989  * find a task by one of its numerical ids
1990  *
1991  * find_task_by_pid_ns():
1992  *      finds a task by its pid in the specified namespace
1993  * find_task_by_vpid():
1994  *      finds a task by its virtual pid
1995  *
1996  * see also find_vpid() etc in include/linux/pid.h
1997  */
1998 
1999 extern struct task_struct *find_task_by_vpid(pid_t nr);
2000 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2001 		struct pid_namespace *ns);
2002 
2003 extern void __set_special_pids(struct pid *pid);
2004 
2005 /* per-UID process charging. */
2006 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
2007 static inline struct user_struct *get_uid(struct user_struct *u)
2008 {
2009 	atomic_inc(&u->__count);
2010 	return u;
2011 }
2012 extern void free_uid(struct user_struct *);
2013 extern void release_uids(struct user_namespace *ns);
2014 
2015 #include <asm/current.h>
2016 
2017 extern void do_timer(unsigned long ticks);
2018 
2019 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2020 extern int wake_up_process(struct task_struct *tsk);
2021 extern void wake_up_new_task(struct task_struct *tsk,
2022 				unsigned long clone_flags);
2023 #ifdef CONFIG_SMP
2024  extern void kick_process(struct task_struct *tsk);
2025 #else
2026  static inline void kick_process(struct task_struct *tsk) { }
2027 #endif
2028 extern void sched_fork(struct task_struct *p, int clone_flags);
2029 extern void sched_dead(struct task_struct *p);
2030 
2031 extern void proc_caches_init(void);
2032 extern void flush_signals(struct task_struct *);
2033 extern void __flush_signals(struct task_struct *);
2034 extern void ignore_signals(struct task_struct *);
2035 extern void flush_signal_handlers(struct task_struct *, int force_default);
2036 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2037 
2038 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2039 {
2040 	unsigned long flags;
2041 	int ret;
2042 
2043 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2044 	ret = dequeue_signal(tsk, mask, info);
2045 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2046 
2047 	return ret;
2048 }
2049 
2050 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2051 			      sigset_t *mask);
2052 extern void unblock_all_signals(void);
2053 extern void release_task(struct task_struct * p);
2054 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2055 extern int force_sigsegv(int, struct task_struct *);
2056 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2057 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2058 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2059 extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
2060 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2061 extern int kill_pid(struct pid *pid, int sig, int priv);
2062 extern int kill_proc_info(int, struct siginfo *, pid_t);
2063 extern int do_notify_parent(struct task_struct *, int);
2064 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2065 extern void force_sig(int, struct task_struct *);
2066 extern int send_sig(int, struct task_struct *, int);
2067 extern int zap_other_threads(struct task_struct *p);
2068 extern struct sigqueue *sigqueue_alloc(void);
2069 extern void sigqueue_free(struct sigqueue *);
2070 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2071 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2072 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2073 
2074 static inline int kill_cad_pid(int sig, int priv)
2075 {
2076 	return kill_pid(cad_pid, sig, priv);
2077 }
2078 
2079 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2080 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2081 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2082 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2083 
2084 /*
2085  * True if we are on the alternate signal stack.
2086  */
2087 static inline int on_sig_stack(unsigned long sp)
2088 {
2089 #ifdef CONFIG_STACK_GROWSUP
2090 	return sp >= current->sas_ss_sp &&
2091 		sp - current->sas_ss_sp < current->sas_ss_size;
2092 #else
2093 	return sp > current->sas_ss_sp &&
2094 		sp - current->sas_ss_sp <= current->sas_ss_size;
2095 #endif
2096 }
2097 
2098 static inline int sas_ss_flags(unsigned long sp)
2099 {
2100 	return (current->sas_ss_size == 0 ? SS_DISABLE
2101 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2102 }
2103 
2104 /*
2105  * Routines for handling mm_structs
2106  */
2107 extern struct mm_struct * mm_alloc(void);
2108 
2109 /* mmdrop drops the mm and the page tables */
2110 extern void __mmdrop(struct mm_struct *);
2111 static inline void mmdrop(struct mm_struct * mm)
2112 {
2113 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2114 		__mmdrop(mm);
2115 }
2116 
2117 /* mmput gets rid of the mappings and all user-space */
2118 extern void mmput(struct mm_struct *);
2119 /* Grab a reference to a task's mm, if it is not already going away */
2120 extern struct mm_struct *get_task_mm(struct task_struct *task);
2121 /* Remove the current tasks stale references to the old mm_struct */
2122 extern void mm_release(struct task_struct *, struct mm_struct *);
2123 /* Allocate a new mm structure and copy contents from tsk->mm */
2124 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2125 
2126 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2127 			struct task_struct *, struct pt_regs *);
2128 extern void flush_thread(void);
2129 extern void exit_thread(void);
2130 
2131 extern void exit_files(struct task_struct *);
2132 extern void __cleanup_sighand(struct sighand_struct *);
2133 
2134 extern void exit_itimers(struct signal_struct *);
2135 extern void flush_itimer_signals(void);
2136 
2137 extern NORET_TYPE void do_group_exit(int);
2138 
2139 extern void daemonize(const char *, ...);
2140 extern int allow_signal(int);
2141 extern int disallow_signal(int);
2142 
2143 extern int do_execve(const char *,
2144 		     const char __user * const __user *,
2145 		     const char __user * const __user *, struct pt_regs *);
2146 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2147 struct task_struct *fork_idle(int);
2148 
2149 extern void set_task_comm(struct task_struct *tsk, char *from);
2150 extern char *get_task_comm(char *to, struct task_struct *tsk);
2151 
2152 #ifdef CONFIG_SMP
2153 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2154 #else
2155 static inline unsigned long wait_task_inactive(struct task_struct *p,
2156 					       long match_state)
2157 {
2158 	return 1;
2159 }
2160 #endif
2161 
2162 #define next_task(p) \
2163 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2164 
2165 #define for_each_process(p) \
2166 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2167 
2168 extern bool current_is_single_threaded(void);
2169 
2170 /*
2171  * Careful: do_each_thread/while_each_thread is a double loop so
2172  *          'break' will not work as expected - use goto instead.
2173  */
2174 #define do_each_thread(g, t) \
2175 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2176 
2177 #define while_each_thread(g, t) \
2178 	while ((t = next_thread(t)) != g)
2179 
2180 static inline int get_nr_threads(struct task_struct *tsk)
2181 {
2182 	return tsk->signal->nr_threads;
2183 }
2184 
2185 /* de_thread depends on thread_group_leader not being a pid based check */
2186 #define thread_group_leader(p)	(p == p->group_leader)
2187 
2188 /* Do to the insanities of de_thread it is possible for a process
2189  * to have the pid of the thread group leader without actually being
2190  * the thread group leader.  For iteration through the pids in proc
2191  * all we care about is that we have a task with the appropriate
2192  * pid, we don't actually care if we have the right task.
2193  */
2194 static inline int has_group_leader_pid(struct task_struct *p)
2195 {
2196 	return p->pid == p->tgid;
2197 }
2198 
2199 static inline
2200 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2201 {
2202 	return p1->tgid == p2->tgid;
2203 }
2204 
2205 static inline struct task_struct *next_thread(const struct task_struct *p)
2206 {
2207 	return list_entry_rcu(p->thread_group.next,
2208 			      struct task_struct, thread_group);
2209 }
2210 
2211 static inline int thread_group_empty(struct task_struct *p)
2212 {
2213 	return list_empty(&p->thread_group);
2214 }
2215 
2216 #define delay_group_leader(p) \
2217 		(thread_group_leader(p) && !thread_group_empty(p))
2218 
2219 static inline int task_detached(struct task_struct *p)
2220 {
2221 	return p->exit_signal == -1;
2222 }
2223 
2224 /*
2225  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2226  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2227  * pins the final release of task.io_context.  Also protects ->cpuset and
2228  * ->cgroup.subsys[].
2229  *
2230  * Nests both inside and outside of read_lock(&tasklist_lock).
2231  * It must not be nested with write_lock_irq(&tasklist_lock),
2232  * neither inside nor outside.
2233  */
2234 static inline void task_lock(struct task_struct *p)
2235 {
2236 	spin_lock(&p->alloc_lock);
2237 }
2238 
2239 static inline void task_unlock(struct task_struct *p)
2240 {
2241 	spin_unlock(&p->alloc_lock);
2242 }
2243 
2244 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2245 							unsigned long *flags);
2246 
2247 #define lock_task_sighand(tsk, flags)					\
2248 ({	struct sighand_struct *__ss;					\
2249 	__cond_lock(&(tsk)->sighand->siglock,				\
2250 		    (__ss = __lock_task_sighand(tsk, flags)));		\
2251 	__ss;								\
2252 })									\
2253 
2254 static inline void unlock_task_sighand(struct task_struct *tsk,
2255 						unsigned long *flags)
2256 {
2257 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2258 }
2259 
2260 #ifndef __HAVE_THREAD_FUNCTIONS
2261 
2262 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2263 #define task_stack_page(task)	((task)->stack)
2264 
2265 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2266 {
2267 	*task_thread_info(p) = *task_thread_info(org);
2268 	task_thread_info(p)->task = p;
2269 }
2270 
2271 static inline unsigned long *end_of_stack(struct task_struct *p)
2272 {
2273 	return (unsigned long *)(task_thread_info(p) + 1);
2274 }
2275 
2276 #endif
2277 
2278 static inline int object_is_on_stack(void *obj)
2279 {
2280 	void *stack = task_stack_page(current);
2281 
2282 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2283 }
2284 
2285 extern void thread_info_cache_init(void);
2286 
2287 #ifdef CONFIG_DEBUG_STACK_USAGE
2288 static inline unsigned long stack_not_used(struct task_struct *p)
2289 {
2290 	unsigned long *n = end_of_stack(p);
2291 
2292 	do { 	/* Skip over canary */
2293 		n++;
2294 	} while (!*n);
2295 
2296 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2297 }
2298 #endif
2299 
2300 /* set thread flags in other task's structures
2301  * - see asm/thread_info.h for TIF_xxxx flags available
2302  */
2303 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2304 {
2305 	set_ti_thread_flag(task_thread_info(tsk), flag);
2306 }
2307 
2308 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2309 {
2310 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2311 }
2312 
2313 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2314 {
2315 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2316 }
2317 
2318 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2319 {
2320 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2321 }
2322 
2323 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2324 {
2325 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2326 }
2327 
2328 static inline void set_tsk_need_resched(struct task_struct *tsk)
2329 {
2330 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2331 }
2332 
2333 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2334 {
2335 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2336 }
2337 
2338 static inline int test_tsk_need_resched(struct task_struct *tsk)
2339 {
2340 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2341 }
2342 
2343 static inline int restart_syscall(void)
2344 {
2345 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2346 	return -ERESTARTNOINTR;
2347 }
2348 
2349 static inline int signal_pending(struct task_struct *p)
2350 {
2351 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2352 }
2353 
2354 static inline int __fatal_signal_pending(struct task_struct *p)
2355 {
2356 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2357 }
2358 
2359 static inline int fatal_signal_pending(struct task_struct *p)
2360 {
2361 	return signal_pending(p) && __fatal_signal_pending(p);
2362 }
2363 
2364 static inline int signal_pending_state(long state, struct task_struct *p)
2365 {
2366 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2367 		return 0;
2368 	if (!signal_pending(p))
2369 		return 0;
2370 
2371 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2372 }
2373 
2374 static inline int need_resched(void)
2375 {
2376 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2377 }
2378 
2379 /*
2380  * cond_resched() and cond_resched_lock(): latency reduction via
2381  * explicit rescheduling in places that are safe. The return
2382  * value indicates whether a reschedule was done in fact.
2383  * cond_resched_lock() will drop the spinlock before scheduling,
2384  * cond_resched_softirq() will enable bhs before scheduling.
2385  */
2386 extern int _cond_resched(void);
2387 
2388 #define cond_resched() ({			\
2389 	__might_sleep(__FILE__, __LINE__, 0);	\
2390 	_cond_resched();			\
2391 })
2392 
2393 extern int __cond_resched_lock(spinlock_t *lock);
2394 
2395 #ifdef CONFIG_PREEMPT
2396 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2397 #else
2398 #define PREEMPT_LOCK_OFFSET	0
2399 #endif
2400 
2401 #define cond_resched_lock(lock) ({				\
2402 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2403 	__cond_resched_lock(lock);				\
2404 })
2405 
2406 extern int __cond_resched_softirq(void);
2407 
2408 #define cond_resched_softirq() ({					\
2409 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2410 	__cond_resched_softirq();					\
2411 })
2412 
2413 /*
2414  * Does a critical section need to be broken due to another
2415  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2416  * but a general need for low latency)
2417  */
2418 static inline int spin_needbreak(spinlock_t *lock)
2419 {
2420 #ifdef CONFIG_PREEMPT
2421 	return spin_is_contended(lock);
2422 #else
2423 	return 0;
2424 #endif
2425 }
2426 
2427 /*
2428  * Thread group CPU time accounting.
2429  */
2430 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2431 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2432 
2433 static inline void thread_group_cputime_init(struct signal_struct *sig)
2434 {
2435 	spin_lock_init(&sig->cputimer.lock);
2436 }
2437 
2438 /*
2439  * Reevaluate whether the task has signals pending delivery.
2440  * Wake the task if so.
2441  * This is required every time the blocked sigset_t changes.
2442  * callers must hold sighand->siglock.
2443  */
2444 extern void recalc_sigpending_and_wake(struct task_struct *t);
2445 extern void recalc_sigpending(void);
2446 
2447 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2448 
2449 /*
2450  * Wrappers for p->thread_info->cpu access. No-op on UP.
2451  */
2452 #ifdef CONFIG_SMP
2453 
2454 static inline unsigned int task_cpu(const struct task_struct *p)
2455 {
2456 	return task_thread_info(p)->cpu;
2457 }
2458 
2459 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2460 
2461 #else
2462 
2463 static inline unsigned int task_cpu(const struct task_struct *p)
2464 {
2465 	return 0;
2466 }
2467 
2468 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2469 {
2470 }
2471 
2472 #endif /* CONFIG_SMP */
2473 
2474 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2475 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2476 
2477 extern void normalize_rt_tasks(void);
2478 
2479 #ifdef CONFIG_CGROUP_SCHED
2480 
2481 extern struct task_group init_task_group;
2482 
2483 extern struct task_group *sched_create_group(struct task_group *parent);
2484 extern void sched_destroy_group(struct task_group *tg);
2485 extern void sched_move_task(struct task_struct *tsk);
2486 #ifdef CONFIG_FAIR_GROUP_SCHED
2487 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2488 extern unsigned long sched_group_shares(struct task_group *tg);
2489 #endif
2490 #ifdef CONFIG_RT_GROUP_SCHED
2491 extern int sched_group_set_rt_runtime(struct task_group *tg,
2492 				      long rt_runtime_us);
2493 extern long sched_group_rt_runtime(struct task_group *tg);
2494 extern int sched_group_set_rt_period(struct task_group *tg,
2495 				      long rt_period_us);
2496 extern long sched_group_rt_period(struct task_group *tg);
2497 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2498 #endif
2499 #endif
2500 
2501 extern int task_can_switch_user(struct user_struct *up,
2502 					struct task_struct *tsk);
2503 
2504 #ifdef CONFIG_TASK_XACCT
2505 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2506 {
2507 	tsk->ioac.rchar += amt;
2508 }
2509 
2510 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2511 {
2512 	tsk->ioac.wchar += amt;
2513 }
2514 
2515 static inline void inc_syscr(struct task_struct *tsk)
2516 {
2517 	tsk->ioac.syscr++;
2518 }
2519 
2520 static inline void inc_syscw(struct task_struct *tsk)
2521 {
2522 	tsk->ioac.syscw++;
2523 }
2524 #else
2525 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2526 {
2527 }
2528 
2529 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2530 {
2531 }
2532 
2533 static inline void inc_syscr(struct task_struct *tsk)
2534 {
2535 }
2536 
2537 static inline void inc_syscw(struct task_struct *tsk)
2538 {
2539 }
2540 #endif
2541 
2542 #ifndef TASK_SIZE_OF
2543 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2544 #endif
2545 
2546 /*
2547  * Call the function if the target task is executing on a CPU right now:
2548  */
2549 extern void task_oncpu_function_call(struct task_struct *p,
2550 				     void (*func) (void *info), void *info);
2551 
2552 
2553 #ifdef CONFIG_MM_OWNER
2554 extern void mm_update_next_owner(struct mm_struct *mm);
2555 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2556 #else
2557 static inline void mm_update_next_owner(struct mm_struct *mm)
2558 {
2559 }
2560 
2561 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2562 {
2563 }
2564 #endif /* CONFIG_MM_OWNER */
2565 
2566 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2567 		unsigned int limit)
2568 {
2569 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2570 }
2571 
2572 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2573 		unsigned int limit)
2574 {
2575 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2576 }
2577 
2578 static inline unsigned long rlimit(unsigned int limit)
2579 {
2580 	return task_rlimit(current, limit);
2581 }
2582 
2583 static inline unsigned long rlimit_max(unsigned int limit)
2584 {
2585 	return task_rlimit_max(current, limit);
2586 }
2587 
2588 #endif /* __KERNEL__ */
2589 
2590 #endif
2591