xref: /linux/include/linux/sched.h (revision 9429ec96c2718c0d1e3317cf60a87a0405223814)
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 /* 0x02000000 was previously the unused CLONE_STOPPED (Start in stopped state)
25    and is now available for re-use. */
26 #define CLONE_NEWUTS		0x04000000	/* New utsname group? */
27 #define CLONE_NEWIPC		0x08000000	/* New ipcs */
28 #define CLONE_NEWUSER		0x10000000	/* New user namespace */
29 #define CLONE_NEWPID		0x20000000	/* New pid namespace */
30 #define CLONE_NEWNET		0x40000000	/* New network namespace */
31 #define CLONE_IO		0x80000000	/* Clone io context */
32 
33 /*
34  * Scheduling policies
35  */
36 #define SCHED_NORMAL		0
37 #define SCHED_FIFO		1
38 #define SCHED_RR		2
39 #define SCHED_BATCH		3
40 /* SCHED_ISO: reserved but not implemented yet */
41 #define SCHED_IDLE		5
42 /* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
43 #define SCHED_RESET_ON_FORK     0x40000000
44 
45 #ifdef __KERNEL__
46 
47 struct sched_param {
48 	int sched_priority;
49 };
50 
51 #include <asm/param.h>	/* for HZ */
52 
53 #include <linux/capability.h>
54 #include <linux/threads.h>
55 #include <linux/kernel.h>
56 #include <linux/types.h>
57 #include <linux/timex.h>
58 #include <linux/jiffies.h>
59 #include <linux/rbtree.h>
60 #include <linux/thread_info.h>
61 #include <linux/cpumask.h>
62 #include <linux/errno.h>
63 #include <linux/nodemask.h>
64 #include <linux/mm_types.h>
65 
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/compiler.h>
74 #include <linux/completion.h>
75 #include <linux/pid.h>
76 #include <linux/percpu.h>
77 #include <linux/topology.h>
78 #include <linux/proportions.h>
79 #include <linux/seccomp.h>
80 #include <linux/rcupdate.h>
81 #include <linux/rculist.h>
82 #include <linux/rtmutex.h>
83 
84 #include <linux/time.h>
85 #include <linux/param.h>
86 #include <linux/resource.h>
87 #include <linux/timer.h>
88 #include <linux/hrtimer.h>
89 #include <linux/task_io_accounting.h>
90 #include <linux/latencytop.h>
91 #include <linux/cred.h>
92 #include <linux/llist.h>
93 #include <linux/uidgid.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 struct blk_plug;
104 
105 /*
106  * List of flags we want to share for kernel threads,
107  * if only because they are not used by them anyway.
108  */
109 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
110 
111 /*
112  * These are the constant used to fake the fixed-point load-average
113  * counting. Some notes:
114  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
115  *    a load-average precision of 10 bits integer + 11 bits fractional
116  *  - if you want to count load-averages more often, you need more
117  *    precision, or rounding will get you. With 2-second counting freq,
118  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
119  *    11 bit fractions.
120  */
121 extern unsigned long avenrun[];		/* Load averages */
122 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
123 
124 #define FSHIFT		11		/* nr of bits of precision */
125 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
126 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
127 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
128 #define EXP_5		2014		/* 1/exp(5sec/5min) */
129 #define EXP_15		2037		/* 1/exp(5sec/15min) */
130 
131 #define CALC_LOAD(load,exp,n) \
132 	load *= exp; \
133 	load += n*(FIXED_1-exp); \
134 	load >>= FSHIFT;
135 
136 extern unsigned long total_forks;
137 extern int nr_threads;
138 DECLARE_PER_CPU(unsigned long, process_counts);
139 extern int nr_processes(void);
140 extern unsigned long nr_running(void);
141 extern unsigned long nr_uninterruptible(void);
142 extern unsigned long nr_iowait(void);
143 extern unsigned long nr_iowait_cpu(int cpu);
144 extern unsigned long this_cpu_load(void);
145 
146 
147 extern void calc_global_load(unsigned long ticks);
148 extern void update_cpu_load_nohz(void);
149 
150 extern unsigned long get_parent_ip(unsigned long addr);
151 
152 struct seq_file;
153 struct cfs_rq;
154 struct task_group;
155 #ifdef CONFIG_SCHED_DEBUG
156 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
157 extern void proc_sched_set_task(struct task_struct *p);
158 extern void
159 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
160 #else
161 static inline void
162 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
163 {
164 }
165 static inline void proc_sched_set_task(struct task_struct *p)
166 {
167 }
168 static inline void
169 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
170 {
171 }
172 #endif
173 
174 /*
175  * Task state bitmask. NOTE! These bits are also
176  * encoded in fs/proc/array.c: get_task_state().
177  *
178  * We have two separate sets of flags: task->state
179  * is about runnability, while task->exit_state are
180  * about the task exiting. Confusing, but this way
181  * modifying one set can't modify the other one by
182  * mistake.
183  */
184 #define TASK_RUNNING		0
185 #define TASK_INTERRUPTIBLE	1
186 #define TASK_UNINTERRUPTIBLE	2
187 #define __TASK_STOPPED		4
188 #define __TASK_TRACED		8
189 /* in tsk->exit_state */
190 #define EXIT_ZOMBIE		16
191 #define EXIT_DEAD		32
192 /* in tsk->state again */
193 #define TASK_DEAD		64
194 #define TASK_WAKEKILL		128
195 #define TASK_WAKING		256
196 #define TASK_STATE_MAX		512
197 
198 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
199 
200 extern char ___assert_task_state[1 - 2*!!(
201 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
202 
203 /* Convenience macros for the sake of set_task_state */
204 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
205 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
206 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
207 
208 /* Convenience macros for the sake of wake_up */
209 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
210 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
211 
212 /* get_task_state() */
213 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
214 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
215 				 __TASK_TRACED)
216 
217 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
218 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
219 #define task_is_dead(task)	((task)->exit_state != 0)
220 #define task_is_stopped_or_traced(task)	\
221 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
222 #define task_contributes_to_load(task)	\
223 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
224 				 (task->flags & PF_FROZEN) == 0)
225 
226 #define __set_task_state(tsk, state_value)		\
227 	do { (tsk)->state = (state_value); } while (0)
228 #define set_task_state(tsk, state_value)		\
229 	set_mb((tsk)->state, (state_value))
230 
231 /*
232  * set_current_state() includes a barrier so that the write of current->state
233  * is correctly serialised wrt the caller's subsequent test of whether to
234  * actually sleep:
235  *
236  *	set_current_state(TASK_UNINTERRUPTIBLE);
237  *	if (do_i_need_to_sleep())
238  *		schedule();
239  *
240  * If the caller does not need such serialisation then use __set_current_state()
241  */
242 #define __set_current_state(state_value)			\
243 	do { current->state = (state_value); } while (0)
244 #define set_current_state(state_value)		\
245 	set_mb(current->state, (state_value))
246 
247 /* Task command name length */
248 #define TASK_COMM_LEN 16
249 
250 #include <linux/spinlock.h>
251 
252 /*
253  * This serializes "schedule()" and also protects
254  * the run-queue from deletions/modifications (but
255  * _adding_ to the beginning of the run-queue has
256  * a separate lock).
257  */
258 extern rwlock_t tasklist_lock;
259 extern spinlock_t mmlist_lock;
260 
261 struct task_struct;
262 
263 #ifdef CONFIG_PROVE_RCU
264 extern int lockdep_tasklist_lock_is_held(void);
265 #endif /* #ifdef CONFIG_PROVE_RCU */
266 
267 extern void sched_init(void);
268 extern void sched_init_smp(void);
269 extern asmlinkage void schedule_tail(struct task_struct *prev);
270 extern void init_idle(struct task_struct *idle, int cpu);
271 extern void init_idle_bootup_task(struct task_struct *idle);
272 
273 extern int runqueue_is_locked(int cpu);
274 
275 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
276 extern void select_nohz_load_balancer(int stop_tick);
277 extern void set_cpu_sd_state_idle(void);
278 extern int get_nohz_timer_target(void);
279 #else
280 static inline void select_nohz_load_balancer(int stop_tick) { }
281 static inline void set_cpu_sd_state_idle(void) { }
282 #endif
283 
284 /*
285  * Only dump TASK_* tasks. (0 for all tasks)
286  */
287 extern void show_state_filter(unsigned long state_filter);
288 
289 static inline void show_state(void)
290 {
291 	show_state_filter(0);
292 }
293 
294 extern void show_regs(struct pt_regs *);
295 
296 /*
297  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
298  * task), SP is the stack pointer of the first frame that should be shown in the back
299  * trace (or NULL if the entire call-chain of the task should be shown).
300  */
301 extern void show_stack(struct task_struct *task, unsigned long *sp);
302 
303 void io_schedule(void);
304 long io_schedule_timeout(long timeout);
305 
306 extern void cpu_init (void);
307 extern void trap_init(void);
308 extern void update_process_times(int user);
309 extern void scheduler_tick(void);
310 
311 extern void sched_show_task(struct task_struct *p);
312 
313 #ifdef CONFIG_LOCKUP_DETECTOR
314 extern void touch_softlockup_watchdog(void);
315 extern void touch_softlockup_watchdog_sync(void);
316 extern void touch_all_softlockup_watchdogs(void);
317 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
318 				  void __user *buffer,
319 				  size_t *lenp, loff_t *ppos);
320 extern unsigned int  softlockup_panic;
321 void lockup_detector_init(void);
322 #else
323 static inline void touch_softlockup_watchdog(void)
324 {
325 }
326 static inline void touch_softlockup_watchdog_sync(void)
327 {
328 }
329 static inline void touch_all_softlockup_watchdogs(void)
330 {
331 }
332 static inline void lockup_detector_init(void)
333 {
334 }
335 #endif
336 
337 #ifdef CONFIG_DETECT_HUNG_TASK
338 extern unsigned int  sysctl_hung_task_panic;
339 extern unsigned long sysctl_hung_task_check_count;
340 extern unsigned long sysctl_hung_task_timeout_secs;
341 extern unsigned long sysctl_hung_task_warnings;
342 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
343 					 void __user *buffer,
344 					 size_t *lenp, loff_t *ppos);
345 #else
346 /* Avoid need for ifdefs elsewhere in the code */
347 enum { sysctl_hung_task_timeout_secs = 0 };
348 #endif
349 
350 /* Attach to any functions which should be ignored in wchan output. */
351 #define __sched		__attribute__((__section__(".sched.text")))
352 
353 /* Linker adds these: start and end of __sched functions */
354 extern char __sched_text_start[], __sched_text_end[];
355 
356 /* Is this address in the __sched functions? */
357 extern int in_sched_functions(unsigned long addr);
358 
359 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
360 extern signed long schedule_timeout(signed long timeout);
361 extern signed long schedule_timeout_interruptible(signed long timeout);
362 extern signed long schedule_timeout_killable(signed long timeout);
363 extern signed long schedule_timeout_uninterruptible(signed long timeout);
364 asmlinkage void schedule(void);
365 extern void schedule_preempt_disabled(void);
366 extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
367 
368 struct nsproxy;
369 struct user_namespace;
370 
371 /*
372  * Default maximum number of active map areas, this limits the number of vmas
373  * per mm struct. Users can overwrite this number by sysctl but there is a
374  * problem.
375  *
376  * When a program's coredump is generated as ELF format, a section is created
377  * per a vma. In ELF, the number of sections is represented in unsigned short.
378  * This means the number of sections should be smaller than 65535 at coredump.
379  * Because the kernel adds some informative sections to a image of program at
380  * generating coredump, we need some margin. The number of extra sections is
381  * 1-3 now and depends on arch. We use "5" as safe margin, here.
382  */
383 #define MAPCOUNT_ELF_CORE_MARGIN	(5)
384 #define DEFAULT_MAX_MAP_COUNT	(USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
385 
386 extern int sysctl_max_map_count;
387 
388 #include <linux/aio.h>
389 
390 #ifdef CONFIG_MMU
391 extern void arch_pick_mmap_layout(struct mm_struct *mm);
392 extern unsigned long
393 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
394 		       unsigned long, unsigned long);
395 extern unsigned long
396 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
397 			  unsigned long len, unsigned long pgoff,
398 			  unsigned long flags);
399 extern void arch_unmap_area(struct mm_struct *, unsigned long);
400 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
401 #else
402 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
403 #endif
404 
405 
406 extern void set_dumpable(struct mm_struct *mm, int value);
407 extern int get_dumpable(struct mm_struct *mm);
408 
409 /* get/set_dumpable() values */
410 #define SUID_DUMPABLE_DISABLED	0
411 #define SUID_DUMPABLE_ENABLED	1
412 #define SUID_DUMPABLE_SAFE	2
413 
414 /* mm flags */
415 /* dumpable bits */
416 #define MMF_DUMPABLE      0  /* core dump is permitted */
417 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
418 
419 #define MMF_DUMPABLE_BITS 2
420 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
421 
422 /* coredump filter bits */
423 #define MMF_DUMP_ANON_PRIVATE	2
424 #define MMF_DUMP_ANON_SHARED	3
425 #define MMF_DUMP_MAPPED_PRIVATE	4
426 #define MMF_DUMP_MAPPED_SHARED	5
427 #define MMF_DUMP_ELF_HEADERS	6
428 #define MMF_DUMP_HUGETLB_PRIVATE 7
429 #define MMF_DUMP_HUGETLB_SHARED  8
430 
431 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
432 #define MMF_DUMP_FILTER_BITS	7
433 #define MMF_DUMP_FILTER_MASK \
434 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
435 #define MMF_DUMP_FILTER_DEFAULT \
436 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
437 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
438 
439 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
440 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
441 #else
442 # define MMF_DUMP_MASK_DEFAULT_ELF	0
443 #endif
444 					/* leave room for more dump flags */
445 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
446 #define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
447 #define MMF_EXE_FILE_CHANGED	18	/* see prctl_set_mm_exe_file() */
448 
449 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
450 
451 struct sighand_struct {
452 	atomic_t		count;
453 	struct k_sigaction	action[_NSIG];
454 	spinlock_t		siglock;
455 	wait_queue_head_t	signalfd_wqh;
456 };
457 
458 struct pacct_struct {
459 	int			ac_flag;
460 	long			ac_exitcode;
461 	unsigned long		ac_mem;
462 	cputime_t		ac_utime, ac_stime;
463 	unsigned long		ac_minflt, ac_majflt;
464 };
465 
466 struct cpu_itimer {
467 	cputime_t expires;
468 	cputime_t incr;
469 	u32 error;
470 	u32 incr_error;
471 };
472 
473 /**
474  * struct task_cputime - collected CPU time counts
475  * @utime:		time spent in user mode, in &cputime_t units
476  * @stime:		time spent in kernel mode, in &cputime_t units
477  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
478  *
479  * This structure groups together three kinds of CPU time that are
480  * tracked for threads and thread groups.  Most things considering
481  * CPU time want to group these counts together and treat all three
482  * of them in parallel.
483  */
484 struct task_cputime {
485 	cputime_t utime;
486 	cputime_t stime;
487 	unsigned long long sum_exec_runtime;
488 };
489 /* Alternate field names when used to cache expirations. */
490 #define prof_exp	stime
491 #define virt_exp	utime
492 #define sched_exp	sum_exec_runtime
493 
494 #define INIT_CPUTIME	\
495 	(struct task_cputime) {					\
496 		.utime = 0,					\
497 		.stime = 0,					\
498 		.sum_exec_runtime = 0,				\
499 	}
500 
501 /*
502  * Disable preemption until the scheduler is running.
503  * Reset by start_kernel()->sched_init()->init_idle().
504  *
505  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
506  * before the scheduler is active -- see should_resched().
507  */
508 #define INIT_PREEMPT_COUNT	(1 + PREEMPT_ACTIVE)
509 
510 /**
511  * struct thread_group_cputimer - thread group interval timer counts
512  * @cputime:		thread group interval timers.
513  * @running:		non-zero when there are timers running and
514  * 			@cputime receives updates.
515  * @lock:		lock for fields in this struct.
516  *
517  * This structure contains the version of task_cputime, above, that is
518  * used for thread group CPU timer calculations.
519  */
520 struct thread_group_cputimer {
521 	struct task_cputime cputime;
522 	int running;
523 	raw_spinlock_t lock;
524 };
525 
526 #include <linux/rwsem.h>
527 struct autogroup;
528 
529 /*
530  * NOTE! "signal_struct" does not have its own
531  * locking, because a shared signal_struct always
532  * implies a shared sighand_struct, so locking
533  * sighand_struct is always a proper superset of
534  * the locking of signal_struct.
535  */
536 struct signal_struct {
537 	atomic_t		sigcnt;
538 	atomic_t		live;
539 	int			nr_threads;
540 
541 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
542 
543 	/* current thread group signal load-balancing target: */
544 	struct task_struct	*curr_target;
545 
546 	/* shared signal handling: */
547 	struct sigpending	shared_pending;
548 
549 	/* thread group exit support */
550 	int			group_exit_code;
551 	/* overloaded:
552 	 * - notify group_exit_task when ->count is equal to notify_count
553 	 * - everyone except group_exit_task is stopped during signal delivery
554 	 *   of fatal signals, group_exit_task processes the signal.
555 	 */
556 	int			notify_count;
557 	struct task_struct	*group_exit_task;
558 
559 	/* thread group stop support, overloads group_exit_code too */
560 	int			group_stop_count;
561 	unsigned int		flags; /* see SIGNAL_* flags below */
562 
563 	/*
564 	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
565 	 * manager, to re-parent orphan (double-forking) child processes
566 	 * to this process instead of 'init'. The service manager is
567 	 * able to receive SIGCHLD signals and is able to investigate
568 	 * the process until it calls wait(). All children of this
569 	 * process will inherit a flag if they should look for a
570 	 * child_subreaper process at exit.
571 	 */
572 	unsigned int		is_child_subreaper:1;
573 	unsigned int		has_child_subreaper:1;
574 
575 	/* POSIX.1b Interval Timers */
576 	struct list_head posix_timers;
577 
578 	/* ITIMER_REAL timer for the process */
579 	struct hrtimer real_timer;
580 	struct pid *leader_pid;
581 	ktime_t it_real_incr;
582 
583 	/*
584 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
585 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
586 	 * values are defined to 0 and 1 respectively
587 	 */
588 	struct cpu_itimer it[2];
589 
590 	/*
591 	 * Thread group totals for process CPU timers.
592 	 * See thread_group_cputimer(), et al, for details.
593 	 */
594 	struct thread_group_cputimer cputimer;
595 
596 	/* Earliest-expiration cache. */
597 	struct task_cputime cputime_expires;
598 
599 	struct list_head cpu_timers[3];
600 
601 	struct pid *tty_old_pgrp;
602 
603 	/* boolean value for session group leader */
604 	int leader;
605 
606 	struct tty_struct *tty; /* NULL if no tty */
607 
608 #ifdef CONFIG_SCHED_AUTOGROUP
609 	struct autogroup *autogroup;
610 #endif
611 	/*
612 	 * Cumulative resource counters for dead threads in the group,
613 	 * and for reaped dead child processes forked by this group.
614 	 * Live threads maintain their own counters and add to these
615 	 * in __exit_signal, except for the group leader.
616 	 */
617 	cputime_t utime, stime, cutime, cstime;
618 	cputime_t gtime;
619 	cputime_t cgtime;
620 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
621 	cputime_t prev_utime, prev_stime;
622 #endif
623 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
624 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
625 	unsigned long inblock, oublock, cinblock, coublock;
626 	unsigned long maxrss, cmaxrss;
627 	struct task_io_accounting ioac;
628 
629 	/*
630 	 * Cumulative ns of schedule CPU time fo dead threads in the
631 	 * group, not including a zombie group leader, (This only differs
632 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
633 	 * other than jiffies.)
634 	 */
635 	unsigned long long sum_sched_runtime;
636 
637 	/*
638 	 * We don't bother to synchronize most readers of this at all,
639 	 * because there is no reader checking a limit that actually needs
640 	 * to get both rlim_cur and rlim_max atomically, and either one
641 	 * alone is a single word that can safely be read normally.
642 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
643 	 * protect this instead of the siglock, because they really
644 	 * have no need to disable irqs.
645 	 */
646 	struct rlimit rlim[RLIM_NLIMITS];
647 
648 #ifdef CONFIG_BSD_PROCESS_ACCT
649 	struct pacct_struct pacct;	/* per-process accounting information */
650 #endif
651 #ifdef CONFIG_TASKSTATS
652 	struct taskstats *stats;
653 #endif
654 #ifdef CONFIG_AUDIT
655 	unsigned audit_tty;
656 	struct tty_audit_buf *tty_audit_buf;
657 #endif
658 #ifdef CONFIG_CGROUPS
659 	/*
660 	 * group_rwsem prevents new tasks from entering the threadgroup and
661 	 * member tasks from exiting,a more specifically, setting of
662 	 * PF_EXITING.  fork and exit paths are protected with this rwsem
663 	 * using threadgroup_change_begin/end().  Users which require
664 	 * threadgroup to remain stable should use threadgroup_[un]lock()
665 	 * which also takes care of exec path.  Currently, cgroup is the
666 	 * only user.
667 	 */
668 	struct rw_semaphore group_rwsem;
669 #endif
670 
671 	int oom_adj;		/* OOM kill score adjustment (bit shift) */
672 	int oom_score_adj;	/* OOM kill score adjustment */
673 	int oom_score_adj_min;	/* OOM kill score adjustment minimum value.
674 				 * Only settable by CAP_SYS_RESOURCE. */
675 
676 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
677 					 * credential calculations
678 					 * (notably. ptrace) */
679 };
680 
681 /* Context switch must be unlocked if interrupts are to be enabled */
682 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
683 # define __ARCH_WANT_UNLOCKED_CTXSW
684 #endif
685 
686 /*
687  * Bits in flags field of signal_struct.
688  */
689 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
690 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
691 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
692 /*
693  * Pending notifications to parent.
694  */
695 #define SIGNAL_CLD_STOPPED	0x00000010
696 #define SIGNAL_CLD_CONTINUED	0x00000020
697 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
698 
699 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
700 
701 /* If true, all threads except ->group_exit_task have pending SIGKILL */
702 static inline int signal_group_exit(const struct signal_struct *sig)
703 {
704 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
705 		(sig->group_exit_task != NULL);
706 }
707 
708 /*
709  * Some day this will be a full-fledged user tracking system..
710  */
711 struct user_struct {
712 	atomic_t __count;	/* reference count */
713 	atomic_t processes;	/* How many processes does this user have? */
714 	atomic_t files;		/* How many open files does this user have? */
715 	atomic_t sigpending;	/* How many pending signals does this user have? */
716 #ifdef CONFIG_INOTIFY_USER
717 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
718 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
719 #endif
720 #ifdef CONFIG_FANOTIFY
721 	atomic_t fanotify_listeners;
722 #endif
723 #ifdef CONFIG_EPOLL
724 	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
725 #endif
726 #ifdef CONFIG_POSIX_MQUEUE
727 	/* protected by mq_lock	*/
728 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
729 #endif
730 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
731 
732 #ifdef CONFIG_KEYS
733 	struct key *uid_keyring;	/* UID specific keyring */
734 	struct key *session_keyring;	/* UID's default session keyring */
735 #endif
736 
737 	/* Hash table maintenance information */
738 	struct hlist_node uidhash_node;
739 	kuid_t uid;
740 
741 #ifdef CONFIG_PERF_EVENTS
742 	atomic_long_t locked_vm;
743 #endif
744 };
745 
746 extern int uids_sysfs_init(void);
747 
748 extern struct user_struct *find_user(kuid_t);
749 
750 extern struct user_struct root_user;
751 #define INIT_USER (&root_user)
752 
753 
754 struct backing_dev_info;
755 struct reclaim_state;
756 
757 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
758 struct sched_info {
759 	/* cumulative counters */
760 	unsigned long pcount;	      /* # of times run on this cpu */
761 	unsigned long long run_delay; /* time spent waiting on a runqueue */
762 
763 	/* timestamps */
764 	unsigned long long last_arrival,/* when we last ran on a cpu */
765 			   last_queued;	/* when we were last queued to run */
766 };
767 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
768 
769 #ifdef CONFIG_TASK_DELAY_ACCT
770 struct task_delay_info {
771 	spinlock_t	lock;
772 	unsigned int	flags;	/* Private per-task flags */
773 
774 	/* For each stat XXX, add following, aligned appropriately
775 	 *
776 	 * struct timespec XXX_start, XXX_end;
777 	 * u64 XXX_delay;
778 	 * u32 XXX_count;
779 	 *
780 	 * Atomicity of updates to XXX_delay, XXX_count protected by
781 	 * single lock above (split into XXX_lock if contention is an issue).
782 	 */
783 
784 	/*
785 	 * XXX_count is incremented on every XXX operation, the delay
786 	 * associated with the operation is added to XXX_delay.
787 	 * XXX_delay contains the accumulated delay time in nanoseconds.
788 	 */
789 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
790 	u64 blkio_delay;	/* wait for sync block io completion */
791 	u64 swapin_delay;	/* wait for swapin block io completion */
792 	u32 blkio_count;	/* total count of the number of sync block */
793 				/* io operations performed */
794 	u32 swapin_count;	/* total count of the number of swapin block */
795 				/* io operations performed */
796 
797 	struct timespec freepages_start, freepages_end;
798 	u64 freepages_delay;	/* wait for memory reclaim */
799 	u32 freepages_count;	/* total count of memory reclaim */
800 };
801 #endif	/* CONFIG_TASK_DELAY_ACCT */
802 
803 static inline int sched_info_on(void)
804 {
805 #ifdef CONFIG_SCHEDSTATS
806 	return 1;
807 #elif defined(CONFIG_TASK_DELAY_ACCT)
808 	extern int delayacct_on;
809 	return delayacct_on;
810 #else
811 	return 0;
812 #endif
813 }
814 
815 enum cpu_idle_type {
816 	CPU_IDLE,
817 	CPU_NOT_IDLE,
818 	CPU_NEWLY_IDLE,
819 	CPU_MAX_IDLE_TYPES
820 };
821 
822 /*
823  * Increase resolution of nice-level calculations for 64-bit architectures.
824  * The extra resolution improves shares distribution and load balancing of
825  * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
826  * hierarchies, especially on larger systems. This is not a user-visible change
827  * and does not change the user-interface for setting shares/weights.
828  *
829  * We increase resolution only if we have enough bits to allow this increased
830  * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
831  * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
832  * increased costs.
833  */
834 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
835 # define SCHED_LOAD_RESOLUTION	10
836 # define scale_load(w)		((w) << SCHED_LOAD_RESOLUTION)
837 # define scale_load_down(w)	((w) >> SCHED_LOAD_RESOLUTION)
838 #else
839 # define SCHED_LOAD_RESOLUTION	0
840 # define scale_load(w)		(w)
841 # define scale_load_down(w)	(w)
842 #endif
843 
844 #define SCHED_LOAD_SHIFT	(10 + SCHED_LOAD_RESOLUTION)
845 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
846 
847 /*
848  * Increase resolution of cpu_power calculations
849  */
850 #define SCHED_POWER_SHIFT	10
851 #define SCHED_POWER_SCALE	(1L << SCHED_POWER_SHIFT)
852 
853 /*
854  * sched-domains (multiprocessor balancing) declarations:
855  */
856 #ifdef CONFIG_SMP
857 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
858 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
859 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
860 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
861 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
862 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
863 #define SD_PREFER_LOCAL		0x0040  /* Prefer to keep tasks local to this domain */
864 #define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
865 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
866 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
867 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
868 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
869 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
870 
871 extern int __weak arch_sd_sibiling_asym_packing(void);
872 
873 struct sched_group_power {
874 	atomic_t ref;
875 	/*
876 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
877 	 * single CPU.
878 	 */
879 	unsigned int power, power_orig;
880 	unsigned long next_update;
881 	/*
882 	 * Number of busy cpus in this group.
883 	 */
884 	atomic_t nr_busy_cpus;
885 
886 	unsigned long cpumask[0]; /* iteration mask */
887 };
888 
889 struct sched_group {
890 	struct sched_group *next;	/* Must be a circular list */
891 	atomic_t ref;
892 
893 	unsigned int group_weight;
894 	struct sched_group_power *sgp;
895 
896 	/*
897 	 * The CPUs this group covers.
898 	 *
899 	 * NOTE: this field is variable length. (Allocated dynamically
900 	 * by attaching extra space to the end of the structure,
901 	 * depending on how many CPUs the kernel has booted up with)
902 	 */
903 	unsigned long cpumask[0];
904 };
905 
906 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
907 {
908 	return to_cpumask(sg->cpumask);
909 }
910 
911 /*
912  * cpumask masking which cpus in the group are allowed to iterate up the domain
913  * tree.
914  */
915 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
916 {
917 	return to_cpumask(sg->sgp->cpumask);
918 }
919 
920 /**
921  * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
922  * @group: The group whose first cpu is to be returned.
923  */
924 static inline unsigned int group_first_cpu(struct sched_group *group)
925 {
926 	return cpumask_first(sched_group_cpus(group));
927 }
928 
929 struct sched_domain_attr {
930 	int relax_domain_level;
931 };
932 
933 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
934 	.relax_domain_level = -1,			\
935 }
936 
937 extern int sched_domain_level_max;
938 
939 struct sched_domain {
940 	/* These fields must be setup */
941 	struct sched_domain *parent;	/* top domain must be null terminated */
942 	struct sched_domain *child;	/* bottom domain must be null terminated */
943 	struct sched_group *groups;	/* the balancing groups of the domain */
944 	unsigned long min_interval;	/* Minimum balance interval ms */
945 	unsigned long max_interval;	/* Maximum balance interval ms */
946 	unsigned int busy_factor;	/* less balancing by factor if busy */
947 	unsigned int imbalance_pct;	/* No balance until over watermark */
948 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
949 	unsigned int busy_idx;
950 	unsigned int idle_idx;
951 	unsigned int newidle_idx;
952 	unsigned int wake_idx;
953 	unsigned int forkexec_idx;
954 	unsigned int smt_gain;
955 	int flags;			/* See SD_* */
956 	int level;
957 
958 	/* Runtime fields. */
959 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
960 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
961 	unsigned int nr_balance_failed; /* initialise to 0 */
962 
963 	u64 last_update;
964 
965 #ifdef CONFIG_SCHEDSTATS
966 	/* load_balance() stats */
967 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
968 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
969 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
970 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
971 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
972 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
973 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
974 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
975 
976 	/* Active load balancing */
977 	unsigned int alb_count;
978 	unsigned int alb_failed;
979 	unsigned int alb_pushed;
980 
981 	/* SD_BALANCE_EXEC stats */
982 	unsigned int sbe_count;
983 	unsigned int sbe_balanced;
984 	unsigned int sbe_pushed;
985 
986 	/* SD_BALANCE_FORK stats */
987 	unsigned int sbf_count;
988 	unsigned int sbf_balanced;
989 	unsigned int sbf_pushed;
990 
991 	/* try_to_wake_up() stats */
992 	unsigned int ttwu_wake_remote;
993 	unsigned int ttwu_move_affine;
994 	unsigned int ttwu_move_balance;
995 #endif
996 #ifdef CONFIG_SCHED_DEBUG
997 	char *name;
998 #endif
999 	union {
1000 		void *private;		/* used during construction */
1001 		struct rcu_head rcu;	/* used during destruction */
1002 	};
1003 
1004 	unsigned int span_weight;
1005 	/*
1006 	 * Span of all CPUs in this domain.
1007 	 *
1008 	 * NOTE: this field is variable length. (Allocated dynamically
1009 	 * by attaching extra space to the end of the structure,
1010 	 * depending on how many CPUs the kernel has booted up with)
1011 	 */
1012 	unsigned long span[0];
1013 };
1014 
1015 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1016 {
1017 	return to_cpumask(sd->span);
1018 }
1019 
1020 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1021 				    struct sched_domain_attr *dattr_new);
1022 
1023 /* Allocate an array of sched domains, for partition_sched_domains(). */
1024 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1025 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1026 
1027 /* Test a flag in parent sched domain */
1028 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1029 {
1030 	if (sd->parent && (sd->parent->flags & flag))
1031 		return 1;
1032 
1033 	return 0;
1034 }
1035 
1036 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1037 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1038 
1039 bool cpus_share_cache(int this_cpu, int that_cpu);
1040 
1041 #else /* CONFIG_SMP */
1042 
1043 struct sched_domain_attr;
1044 
1045 static inline void
1046 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1047 			struct sched_domain_attr *dattr_new)
1048 {
1049 }
1050 
1051 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1052 {
1053 	return true;
1054 }
1055 
1056 #endif	/* !CONFIG_SMP */
1057 
1058 
1059 struct io_context;			/* See blkdev.h */
1060 
1061 
1062 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1063 extern void prefetch_stack(struct task_struct *t);
1064 #else
1065 static inline void prefetch_stack(struct task_struct *t) { }
1066 #endif
1067 
1068 struct audit_context;		/* See audit.c */
1069 struct mempolicy;
1070 struct pipe_inode_info;
1071 struct uts_namespace;
1072 
1073 struct rq;
1074 struct sched_domain;
1075 
1076 /*
1077  * wake flags
1078  */
1079 #define WF_SYNC		0x01		/* waker goes to sleep after wakup */
1080 #define WF_FORK		0x02		/* child wakeup after fork */
1081 #define WF_MIGRATED	0x04		/* internal use, task got migrated */
1082 
1083 #define ENQUEUE_WAKEUP		1
1084 #define ENQUEUE_HEAD		2
1085 #ifdef CONFIG_SMP
1086 #define ENQUEUE_WAKING		4	/* sched_class::task_waking was called */
1087 #else
1088 #define ENQUEUE_WAKING		0
1089 #endif
1090 
1091 #define DEQUEUE_SLEEP		1
1092 
1093 struct sched_class {
1094 	const struct sched_class *next;
1095 
1096 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1097 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1098 	void (*yield_task) (struct rq *rq);
1099 	bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1100 
1101 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1102 
1103 	struct task_struct * (*pick_next_task) (struct rq *rq);
1104 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1105 
1106 #ifdef CONFIG_SMP
1107 	int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1108 
1109 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1110 	void (*post_schedule) (struct rq *this_rq);
1111 	void (*task_waking) (struct task_struct *task);
1112 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1113 
1114 	void (*set_cpus_allowed)(struct task_struct *p,
1115 				 const struct cpumask *newmask);
1116 
1117 	void (*rq_online)(struct rq *rq);
1118 	void (*rq_offline)(struct rq *rq);
1119 #endif
1120 
1121 	void (*set_curr_task) (struct rq *rq);
1122 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1123 	void (*task_fork) (struct task_struct *p);
1124 
1125 	void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1126 	void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1127 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1128 			     int oldprio);
1129 
1130 	unsigned int (*get_rr_interval) (struct rq *rq,
1131 					 struct task_struct *task);
1132 
1133 #ifdef CONFIG_FAIR_GROUP_SCHED
1134 	void (*task_move_group) (struct task_struct *p, int on_rq);
1135 #endif
1136 };
1137 
1138 struct load_weight {
1139 	unsigned long weight, inv_weight;
1140 };
1141 
1142 #ifdef CONFIG_SCHEDSTATS
1143 struct sched_statistics {
1144 	u64			wait_start;
1145 	u64			wait_max;
1146 	u64			wait_count;
1147 	u64			wait_sum;
1148 	u64			iowait_count;
1149 	u64			iowait_sum;
1150 
1151 	u64			sleep_start;
1152 	u64			sleep_max;
1153 	s64			sum_sleep_runtime;
1154 
1155 	u64			block_start;
1156 	u64			block_max;
1157 	u64			exec_max;
1158 	u64			slice_max;
1159 
1160 	u64			nr_migrations_cold;
1161 	u64			nr_failed_migrations_affine;
1162 	u64			nr_failed_migrations_running;
1163 	u64			nr_failed_migrations_hot;
1164 	u64			nr_forced_migrations;
1165 
1166 	u64			nr_wakeups;
1167 	u64			nr_wakeups_sync;
1168 	u64			nr_wakeups_migrate;
1169 	u64			nr_wakeups_local;
1170 	u64			nr_wakeups_remote;
1171 	u64			nr_wakeups_affine;
1172 	u64			nr_wakeups_affine_attempts;
1173 	u64			nr_wakeups_passive;
1174 	u64			nr_wakeups_idle;
1175 };
1176 #endif
1177 
1178 struct sched_entity {
1179 	struct load_weight	load;		/* for load-balancing */
1180 	struct rb_node		run_node;
1181 	struct list_head	group_node;
1182 	unsigned int		on_rq;
1183 
1184 	u64			exec_start;
1185 	u64			sum_exec_runtime;
1186 	u64			vruntime;
1187 	u64			prev_sum_exec_runtime;
1188 
1189 	u64			nr_migrations;
1190 
1191 #ifdef CONFIG_SCHEDSTATS
1192 	struct sched_statistics statistics;
1193 #endif
1194 
1195 #ifdef CONFIG_FAIR_GROUP_SCHED
1196 	struct sched_entity	*parent;
1197 	/* rq on which this entity is (to be) queued: */
1198 	struct cfs_rq		*cfs_rq;
1199 	/* rq "owned" by this entity/group: */
1200 	struct cfs_rq		*my_q;
1201 #endif
1202 };
1203 
1204 struct sched_rt_entity {
1205 	struct list_head run_list;
1206 	unsigned long timeout;
1207 	unsigned int time_slice;
1208 
1209 	struct sched_rt_entity *back;
1210 #ifdef CONFIG_RT_GROUP_SCHED
1211 	struct sched_rt_entity	*parent;
1212 	/* rq on which this entity is (to be) queued: */
1213 	struct rt_rq		*rt_rq;
1214 	/* rq "owned" by this entity/group: */
1215 	struct rt_rq		*my_q;
1216 #endif
1217 };
1218 
1219 /*
1220  * default timeslice is 100 msecs (used only for SCHED_RR tasks).
1221  * Timeslices get refilled after they expire.
1222  */
1223 #define RR_TIMESLICE		(100 * HZ / 1000)
1224 
1225 struct rcu_node;
1226 
1227 enum perf_event_task_context {
1228 	perf_invalid_context = -1,
1229 	perf_hw_context = 0,
1230 	perf_sw_context,
1231 	perf_nr_task_contexts,
1232 };
1233 
1234 struct task_struct {
1235 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1236 	void *stack;
1237 	atomic_t usage;
1238 	unsigned int flags;	/* per process flags, defined below */
1239 	unsigned int ptrace;
1240 
1241 #ifdef CONFIG_SMP
1242 	struct llist_node wake_entry;
1243 	int on_cpu;
1244 #endif
1245 	int on_rq;
1246 
1247 	int prio, static_prio, normal_prio;
1248 	unsigned int rt_priority;
1249 	const struct sched_class *sched_class;
1250 	struct sched_entity se;
1251 	struct sched_rt_entity rt;
1252 #ifdef CONFIG_CGROUP_SCHED
1253 	struct task_group *sched_task_group;
1254 #endif
1255 
1256 #ifdef CONFIG_PREEMPT_NOTIFIERS
1257 	/* list of struct preempt_notifier: */
1258 	struct hlist_head preempt_notifiers;
1259 #endif
1260 
1261 	/*
1262 	 * fpu_counter contains the number of consecutive context switches
1263 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1264 	 * saving becomes unlazy to save the trap. This is an unsigned char
1265 	 * so that after 256 times the counter wraps and the behavior turns
1266 	 * lazy again; this to deal with bursty apps that only use FPU for
1267 	 * a short time
1268 	 */
1269 	unsigned char fpu_counter;
1270 #ifdef CONFIG_BLK_DEV_IO_TRACE
1271 	unsigned int btrace_seq;
1272 #endif
1273 
1274 	unsigned int policy;
1275 	int nr_cpus_allowed;
1276 	cpumask_t cpus_allowed;
1277 
1278 #ifdef CONFIG_PREEMPT_RCU
1279 	int rcu_read_lock_nesting;
1280 	char rcu_read_unlock_special;
1281 	struct list_head rcu_node_entry;
1282 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1283 #ifdef CONFIG_TREE_PREEMPT_RCU
1284 	struct rcu_node *rcu_blocked_node;
1285 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1286 #ifdef CONFIG_RCU_BOOST
1287 	struct rt_mutex *rcu_boost_mutex;
1288 #endif /* #ifdef CONFIG_RCU_BOOST */
1289 
1290 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1291 	struct sched_info sched_info;
1292 #endif
1293 
1294 	struct list_head tasks;
1295 #ifdef CONFIG_SMP
1296 	struct plist_node pushable_tasks;
1297 #endif
1298 
1299 	struct mm_struct *mm, *active_mm;
1300 #ifdef CONFIG_COMPAT_BRK
1301 	unsigned brk_randomized:1;
1302 #endif
1303 #if defined(SPLIT_RSS_COUNTING)
1304 	struct task_rss_stat	rss_stat;
1305 #endif
1306 /* task state */
1307 	int exit_state;
1308 	int exit_code, exit_signal;
1309 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1310 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
1311 	/* ??? */
1312 	unsigned int personality;
1313 	unsigned did_exec:1;
1314 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1315 				 * execve */
1316 	unsigned in_iowait:1;
1317 
1318 	/* task may not gain privileges */
1319 	unsigned no_new_privs:1;
1320 
1321 	/* Revert to default priority/policy when forking */
1322 	unsigned sched_reset_on_fork:1;
1323 	unsigned sched_contributes_to_load:1;
1324 
1325 	pid_t pid;
1326 	pid_t tgid;
1327 
1328 #ifdef CONFIG_CC_STACKPROTECTOR
1329 	/* Canary value for the -fstack-protector gcc feature */
1330 	unsigned long stack_canary;
1331 #endif
1332 	/*
1333 	 * pointers to (original) parent process, youngest child, younger sibling,
1334 	 * older sibling, respectively.  (p->father can be replaced with
1335 	 * p->real_parent->pid)
1336 	 */
1337 	struct task_struct __rcu *real_parent; /* real parent process */
1338 	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1339 	/*
1340 	 * children/sibling forms the list of my natural children
1341 	 */
1342 	struct list_head children;	/* list of my children */
1343 	struct list_head sibling;	/* linkage in my parent's children list */
1344 	struct task_struct *group_leader;	/* threadgroup leader */
1345 
1346 	/*
1347 	 * ptraced is the list of tasks this task is using ptrace on.
1348 	 * This includes both natural children and PTRACE_ATTACH targets.
1349 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1350 	 */
1351 	struct list_head ptraced;
1352 	struct list_head ptrace_entry;
1353 
1354 	/* PID/PID hash table linkage. */
1355 	struct pid_link pids[PIDTYPE_MAX];
1356 	struct list_head thread_group;
1357 
1358 	struct completion *vfork_done;		/* for vfork() */
1359 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1360 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1361 
1362 	cputime_t utime, stime, utimescaled, stimescaled;
1363 	cputime_t gtime;
1364 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1365 	cputime_t prev_utime, prev_stime;
1366 #endif
1367 	unsigned long nvcsw, nivcsw; /* context switch counts */
1368 	struct timespec start_time; 		/* monotonic time */
1369 	struct timespec real_start_time;	/* boot based time */
1370 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1371 	unsigned long min_flt, maj_flt;
1372 
1373 	struct task_cputime cputime_expires;
1374 	struct list_head cpu_timers[3];
1375 
1376 /* process credentials */
1377 	const struct cred __rcu *real_cred; /* objective and real subjective task
1378 					 * credentials (COW) */
1379 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1380 					 * credentials (COW) */
1381 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1382 				     - access with [gs]et_task_comm (which lock
1383 				       it with task_lock())
1384 				     - initialized normally by setup_new_exec */
1385 /* file system info */
1386 	int link_count, total_link_count;
1387 #ifdef CONFIG_SYSVIPC
1388 /* ipc stuff */
1389 	struct sysv_sem sysvsem;
1390 #endif
1391 #ifdef CONFIG_DETECT_HUNG_TASK
1392 /* hung task detection */
1393 	unsigned long last_switch_count;
1394 #endif
1395 /* CPU-specific state of this task */
1396 	struct thread_struct thread;
1397 /* filesystem information */
1398 	struct fs_struct *fs;
1399 /* open file information */
1400 	struct files_struct *files;
1401 /* namespaces */
1402 	struct nsproxy *nsproxy;
1403 /* signal handlers */
1404 	struct signal_struct *signal;
1405 	struct sighand_struct *sighand;
1406 
1407 	sigset_t blocked, real_blocked;
1408 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1409 	struct sigpending pending;
1410 
1411 	unsigned long sas_ss_sp;
1412 	size_t sas_ss_size;
1413 	int (*notifier)(void *priv);
1414 	void *notifier_data;
1415 	sigset_t *notifier_mask;
1416 	struct callback_head *task_works;
1417 
1418 	struct audit_context *audit_context;
1419 #ifdef CONFIG_AUDITSYSCALL
1420 	uid_t loginuid;
1421 	unsigned int sessionid;
1422 #endif
1423 	struct seccomp seccomp;
1424 
1425 /* Thread group tracking */
1426    	u32 parent_exec_id;
1427    	u32 self_exec_id;
1428 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1429  * mempolicy */
1430 	spinlock_t alloc_lock;
1431 
1432 	/* Protection of the PI data structures: */
1433 	raw_spinlock_t pi_lock;
1434 
1435 #ifdef CONFIG_RT_MUTEXES
1436 	/* PI waiters blocked on a rt_mutex held by this task */
1437 	struct plist_head pi_waiters;
1438 	/* Deadlock detection and priority inheritance handling */
1439 	struct rt_mutex_waiter *pi_blocked_on;
1440 #endif
1441 
1442 #ifdef CONFIG_DEBUG_MUTEXES
1443 	/* mutex deadlock detection */
1444 	struct mutex_waiter *blocked_on;
1445 #endif
1446 #ifdef CONFIG_TRACE_IRQFLAGS
1447 	unsigned int irq_events;
1448 	unsigned long hardirq_enable_ip;
1449 	unsigned long hardirq_disable_ip;
1450 	unsigned int hardirq_enable_event;
1451 	unsigned int hardirq_disable_event;
1452 	int hardirqs_enabled;
1453 	int hardirq_context;
1454 	unsigned long softirq_disable_ip;
1455 	unsigned long softirq_enable_ip;
1456 	unsigned int softirq_disable_event;
1457 	unsigned int softirq_enable_event;
1458 	int softirqs_enabled;
1459 	int softirq_context;
1460 #endif
1461 #ifdef CONFIG_LOCKDEP
1462 # define MAX_LOCK_DEPTH 48UL
1463 	u64 curr_chain_key;
1464 	int lockdep_depth;
1465 	unsigned int lockdep_recursion;
1466 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1467 	gfp_t lockdep_reclaim_gfp;
1468 #endif
1469 
1470 /* journalling filesystem info */
1471 	void *journal_info;
1472 
1473 /* stacked block device info */
1474 	struct bio_list *bio_list;
1475 
1476 #ifdef CONFIG_BLOCK
1477 /* stack plugging */
1478 	struct blk_plug *plug;
1479 #endif
1480 
1481 /* VM state */
1482 	struct reclaim_state *reclaim_state;
1483 
1484 	struct backing_dev_info *backing_dev_info;
1485 
1486 	struct io_context *io_context;
1487 
1488 	unsigned long ptrace_message;
1489 	siginfo_t *last_siginfo; /* For ptrace use.  */
1490 	struct task_io_accounting ioac;
1491 #if defined(CONFIG_TASK_XACCT)
1492 	u64 acct_rss_mem1;	/* accumulated rss usage */
1493 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1494 	cputime_t acct_timexpd;	/* stime + utime since last update */
1495 #endif
1496 #ifdef CONFIG_CPUSETS
1497 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1498 	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1499 	int cpuset_mem_spread_rotor;
1500 	int cpuset_slab_spread_rotor;
1501 #endif
1502 #ifdef CONFIG_CGROUPS
1503 	/* Control Group info protected by css_set_lock */
1504 	struct css_set __rcu *cgroups;
1505 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1506 	struct list_head cg_list;
1507 #endif
1508 #ifdef CONFIG_FUTEX
1509 	struct robust_list_head __user *robust_list;
1510 #ifdef CONFIG_COMPAT
1511 	struct compat_robust_list_head __user *compat_robust_list;
1512 #endif
1513 	struct list_head pi_state_list;
1514 	struct futex_pi_state *pi_state_cache;
1515 #endif
1516 #ifdef CONFIG_PERF_EVENTS
1517 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1518 	struct mutex perf_event_mutex;
1519 	struct list_head perf_event_list;
1520 #endif
1521 #ifdef CONFIG_NUMA
1522 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1523 	short il_next;
1524 	short pref_node_fork;
1525 #endif
1526 	struct rcu_head rcu;
1527 
1528 	/*
1529 	 * cache last used pipe for splice
1530 	 */
1531 	struct pipe_inode_info *splice_pipe;
1532 #ifdef	CONFIG_TASK_DELAY_ACCT
1533 	struct task_delay_info *delays;
1534 #endif
1535 #ifdef CONFIG_FAULT_INJECTION
1536 	int make_it_fail;
1537 #endif
1538 	/*
1539 	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1540 	 * balance_dirty_pages() for some dirty throttling pause
1541 	 */
1542 	int nr_dirtied;
1543 	int nr_dirtied_pause;
1544 	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1545 
1546 #ifdef CONFIG_LATENCYTOP
1547 	int latency_record_count;
1548 	struct latency_record latency_record[LT_SAVECOUNT];
1549 #endif
1550 	/*
1551 	 * time slack values; these are used to round up poll() and
1552 	 * select() etc timeout values. These are in nanoseconds.
1553 	 */
1554 	unsigned long timer_slack_ns;
1555 	unsigned long default_timer_slack_ns;
1556 
1557 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1558 	/* Index of current stored address in ret_stack */
1559 	int curr_ret_stack;
1560 	/* Stack of return addresses for return function tracing */
1561 	struct ftrace_ret_stack	*ret_stack;
1562 	/* time stamp for last schedule */
1563 	unsigned long long ftrace_timestamp;
1564 	/*
1565 	 * Number of functions that haven't been traced
1566 	 * because of depth overrun.
1567 	 */
1568 	atomic_t trace_overrun;
1569 	/* Pause for the tracing */
1570 	atomic_t tracing_graph_pause;
1571 #endif
1572 #ifdef CONFIG_TRACING
1573 	/* state flags for use by tracers */
1574 	unsigned long trace;
1575 	/* bitmask and counter of trace recursion */
1576 	unsigned long trace_recursion;
1577 #endif /* CONFIG_TRACING */
1578 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1579 	struct memcg_batch_info {
1580 		int do_batch;	/* incremented when batch uncharge started */
1581 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1582 		unsigned long nr_pages;	/* uncharged usage */
1583 		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1584 	} memcg_batch;
1585 #endif
1586 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1587 	atomic_t ptrace_bp_refcnt;
1588 #endif
1589 #ifdef CONFIG_UPROBES
1590 	struct uprobe_task *utask;
1591 #endif
1592 };
1593 
1594 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1595 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1596 
1597 /*
1598  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1599  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1600  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1601  * values are inverted: lower p->prio value means higher priority.
1602  *
1603  * The MAX_USER_RT_PRIO value allows the actual maximum
1604  * RT priority to be separate from the value exported to
1605  * user-space.  This allows kernel threads to set their
1606  * priority to a value higher than any user task. Note:
1607  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1608  */
1609 
1610 #define MAX_USER_RT_PRIO	100
1611 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1612 
1613 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1614 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1615 
1616 static inline int rt_prio(int prio)
1617 {
1618 	if (unlikely(prio < MAX_RT_PRIO))
1619 		return 1;
1620 	return 0;
1621 }
1622 
1623 static inline int rt_task(struct task_struct *p)
1624 {
1625 	return rt_prio(p->prio);
1626 }
1627 
1628 static inline struct pid *task_pid(struct task_struct *task)
1629 {
1630 	return task->pids[PIDTYPE_PID].pid;
1631 }
1632 
1633 static inline struct pid *task_tgid(struct task_struct *task)
1634 {
1635 	return task->group_leader->pids[PIDTYPE_PID].pid;
1636 }
1637 
1638 /*
1639  * Without tasklist or rcu lock it is not safe to dereference
1640  * the result of task_pgrp/task_session even if task == current,
1641  * we can race with another thread doing sys_setsid/sys_setpgid.
1642  */
1643 static inline struct pid *task_pgrp(struct task_struct *task)
1644 {
1645 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1646 }
1647 
1648 static inline struct pid *task_session(struct task_struct *task)
1649 {
1650 	return task->group_leader->pids[PIDTYPE_SID].pid;
1651 }
1652 
1653 struct pid_namespace;
1654 
1655 /*
1656  * the helpers to get the task's different pids as they are seen
1657  * from various namespaces
1658  *
1659  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1660  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1661  *                     current.
1662  * task_xid_nr_ns()  : id seen from the ns specified;
1663  *
1664  * set_task_vxid()   : assigns a virtual id to a task;
1665  *
1666  * see also pid_nr() etc in include/linux/pid.h
1667  */
1668 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1669 			struct pid_namespace *ns);
1670 
1671 static inline pid_t task_pid_nr(struct task_struct *tsk)
1672 {
1673 	return tsk->pid;
1674 }
1675 
1676 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1677 					struct pid_namespace *ns)
1678 {
1679 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1680 }
1681 
1682 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1683 {
1684 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1685 }
1686 
1687 
1688 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1689 {
1690 	return tsk->tgid;
1691 }
1692 
1693 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1694 
1695 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1696 {
1697 	return pid_vnr(task_tgid(tsk));
1698 }
1699 
1700 
1701 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1702 					struct pid_namespace *ns)
1703 {
1704 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1705 }
1706 
1707 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1708 {
1709 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1710 }
1711 
1712 
1713 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1714 					struct pid_namespace *ns)
1715 {
1716 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1717 }
1718 
1719 static inline pid_t task_session_vnr(struct task_struct *tsk)
1720 {
1721 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1722 }
1723 
1724 /* obsolete, do not use */
1725 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1726 {
1727 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1728 }
1729 
1730 /**
1731  * pid_alive - check that a task structure is not stale
1732  * @p: Task structure to be checked.
1733  *
1734  * Test if a process is not yet dead (at most zombie state)
1735  * If pid_alive fails, then pointers within the task structure
1736  * can be stale and must not be dereferenced.
1737  */
1738 static inline int pid_alive(struct task_struct *p)
1739 {
1740 	return p->pids[PIDTYPE_PID].pid != NULL;
1741 }
1742 
1743 /**
1744  * is_global_init - check if a task structure is init
1745  * @tsk: Task structure to be checked.
1746  *
1747  * Check if a task structure is the first user space task the kernel created.
1748  */
1749 static inline int is_global_init(struct task_struct *tsk)
1750 {
1751 	return tsk->pid == 1;
1752 }
1753 
1754 /*
1755  * is_container_init:
1756  * check whether in the task is init in its own pid namespace.
1757  */
1758 extern int is_container_init(struct task_struct *tsk);
1759 
1760 extern struct pid *cad_pid;
1761 
1762 extern void free_task(struct task_struct *tsk);
1763 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1764 
1765 extern void __put_task_struct(struct task_struct *t);
1766 
1767 static inline void put_task_struct(struct task_struct *t)
1768 {
1769 	if (atomic_dec_and_test(&t->usage))
1770 		__put_task_struct(t);
1771 }
1772 
1773 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1774 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1775 
1776 /*
1777  * Per process flags
1778  */
1779 #define PF_EXITING	0x00000004	/* getting shut down */
1780 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1781 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1782 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1783 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1784 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1785 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1786 #define PF_DUMPCORE	0x00000200	/* dumped core */
1787 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1788 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1789 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
1790 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1791 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1792 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1793 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1794 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1795 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1796 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1797 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1798 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1799 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1800 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1801 #define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1802 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1803 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1804 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1805 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1806 
1807 /*
1808  * Only the _current_ task can read/write to tsk->flags, but other
1809  * tasks can access tsk->flags in readonly mode for example
1810  * with tsk_used_math (like during threaded core dumping).
1811  * There is however an exception to this rule during ptrace
1812  * or during fork: the ptracer task is allowed to write to the
1813  * child->flags of its traced child (same goes for fork, the parent
1814  * can write to the child->flags), because we're guaranteed the
1815  * child is not running and in turn not changing child->flags
1816  * at the same time the parent does it.
1817  */
1818 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1819 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1820 #define clear_used_math() clear_stopped_child_used_math(current)
1821 #define set_used_math() set_stopped_child_used_math(current)
1822 #define conditional_stopped_child_used_math(condition, child) \
1823 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1824 #define conditional_used_math(condition) \
1825 	conditional_stopped_child_used_math(condition, current)
1826 #define copy_to_stopped_child_used_math(child) \
1827 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1828 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1829 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1830 #define used_math() tsk_used_math(current)
1831 
1832 /*
1833  * task->jobctl flags
1834  */
1835 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
1836 
1837 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
1838 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
1839 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
1840 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
1841 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
1842 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
1843 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
1844 
1845 #define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
1846 #define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
1847 #define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
1848 #define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
1849 #define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
1850 #define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
1851 #define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
1852 
1853 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1854 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1855 
1856 extern bool task_set_jobctl_pending(struct task_struct *task,
1857 				    unsigned int mask);
1858 extern void task_clear_jobctl_trapping(struct task_struct *task);
1859 extern void task_clear_jobctl_pending(struct task_struct *task,
1860 				      unsigned int mask);
1861 
1862 #ifdef CONFIG_PREEMPT_RCU
1863 
1864 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1865 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1866 
1867 static inline void rcu_copy_process(struct task_struct *p)
1868 {
1869 	p->rcu_read_lock_nesting = 0;
1870 	p->rcu_read_unlock_special = 0;
1871 #ifdef CONFIG_TREE_PREEMPT_RCU
1872 	p->rcu_blocked_node = NULL;
1873 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1874 #ifdef CONFIG_RCU_BOOST
1875 	p->rcu_boost_mutex = NULL;
1876 #endif /* #ifdef CONFIG_RCU_BOOST */
1877 	INIT_LIST_HEAD(&p->rcu_node_entry);
1878 }
1879 
1880 #else
1881 
1882 static inline void rcu_copy_process(struct task_struct *p)
1883 {
1884 }
1885 
1886 #endif
1887 
1888 static inline void tsk_restore_flags(struct task_struct *task,
1889 				unsigned long orig_flags, unsigned long flags)
1890 {
1891 	task->flags &= ~flags;
1892 	task->flags |= orig_flags & flags;
1893 }
1894 
1895 #ifdef CONFIG_SMP
1896 extern void do_set_cpus_allowed(struct task_struct *p,
1897 			       const struct cpumask *new_mask);
1898 
1899 extern int set_cpus_allowed_ptr(struct task_struct *p,
1900 				const struct cpumask *new_mask);
1901 #else
1902 static inline void do_set_cpus_allowed(struct task_struct *p,
1903 				      const struct cpumask *new_mask)
1904 {
1905 }
1906 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1907 				       const struct cpumask *new_mask)
1908 {
1909 	if (!cpumask_test_cpu(0, new_mask))
1910 		return -EINVAL;
1911 	return 0;
1912 }
1913 #endif
1914 
1915 #ifdef CONFIG_NO_HZ
1916 void calc_load_enter_idle(void);
1917 void calc_load_exit_idle(void);
1918 #else
1919 static inline void calc_load_enter_idle(void) { }
1920 static inline void calc_load_exit_idle(void) { }
1921 #endif /* CONFIG_NO_HZ */
1922 
1923 #ifndef CONFIG_CPUMASK_OFFSTACK
1924 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1925 {
1926 	return set_cpus_allowed_ptr(p, &new_mask);
1927 }
1928 #endif
1929 
1930 /*
1931  * Do not use outside of architecture code which knows its limitations.
1932  *
1933  * sched_clock() has no promise of monotonicity or bounded drift between
1934  * CPUs, use (which you should not) requires disabling IRQs.
1935  *
1936  * Please use one of the three interfaces below.
1937  */
1938 extern unsigned long long notrace sched_clock(void);
1939 /*
1940  * See the comment in kernel/sched/clock.c
1941  */
1942 extern u64 cpu_clock(int cpu);
1943 extern u64 local_clock(void);
1944 extern u64 sched_clock_cpu(int cpu);
1945 
1946 
1947 extern void sched_clock_init(void);
1948 
1949 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1950 static inline void sched_clock_tick(void)
1951 {
1952 }
1953 
1954 static inline void sched_clock_idle_sleep_event(void)
1955 {
1956 }
1957 
1958 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1959 {
1960 }
1961 #else
1962 /*
1963  * Architectures can set this to 1 if they have specified
1964  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1965  * but then during bootup it turns out that sched_clock()
1966  * is reliable after all:
1967  */
1968 extern int sched_clock_stable;
1969 
1970 extern void sched_clock_tick(void);
1971 extern void sched_clock_idle_sleep_event(void);
1972 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1973 #endif
1974 
1975 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1976 /*
1977  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1978  * The reason for this explicit opt-in is not to have perf penalty with
1979  * slow sched_clocks.
1980  */
1981 extern void enable_sched_clock_irqtime(void);
1982 extern void disable_sched_clock_irqtime(void);
1983 #else
1984 static inline void enable_sched_clock_irqtime(void) {}
1985 static inline void disable_sched_clock_irqtime(void) {}
1986 #endif
1987 
1988 extern unsigned long long
1989 task_sched_runtime(struct task_struct *task);
1990 
1991 /* sched_exec is called by processes performing an exec */
1992 #ifdef CONFIG_SMP
1993 extern void sched_exec(void);
1994 #else
1995 #define sched_exec()   {}
1996 #endif
1997 
1998 extern void sched_clock_idle_sleep_event(void);
1999 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2000 
2001 #ifdef CONFIG_HOTPLUG_CPU
2002 extern void idle_task_exit(void);
2003 #else
2004 static inline void idle_task_exit(void) {}
2005 #endif
2006 
2007 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
2008 extern void wake_up_idle_cpu(int cpu);
2009 #else
2010 static inline void wake_up_idle_cpu(int cpu) { }
2011 #endif
2012 
2013 extern unsigned int sysctl_sched_latency;
2014 extern unsigned int sysctl_sched_min_granularity;
2015 extern unsigned int sysctl_sched_wakeup_granularity;
2016 extern unsigned int sysctl_sched_child_runs_first;
2017 
2018 enum sched_tunable_scaling {
2019 	SCHED_TUNABLESCALING_NONE,
2020 	SCHED_TUNABLESCALING_LOG,
2021 	SCHED_TUNABLESCALING_LINEAR,
2022 	SCHED_TUNABLESCALING_END,
2023 };
2024 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
2025 
2026 #ifdef CONFIG_SCHED_DEBUG
2027 extern unsigned int sysctl_sched_migration_cost;
2028 extern unsigned int sysctl_sched_nr_migrate;
2029 extern unsigned int sysctl_sched_time_avg;
2030 extern unsigned int sysctl_timer_migration;
2031 extern unsigned int sysctl_sched_shares_window;
2032 
2033 int sched_proc_update_handler(struct ctl_table *table, int write,
2034 		void __user *buffer, size_t *length,
2035 		loff_t *ppos);
2036 #endif
2037 #ifdef CONFIG_SCHED_DEBUG
2038 static inline unsigned int get_sysctl_timer_migration(void)
2039 {
2040 	return sysctl_timer_migration;
2041 }
2042 #else
2043 static inline unsigned int get_sysctl_timer_migration(void)
2044 {
2045 	return 1;
2046 }
2047 #endif
2048 extern unsigned int sysctl_sched_rt_period;
2049 extern int sysctl_sched_rt_runtime;
2050 
2051 int sched_rt_handler(struct ctl_table *table, int write,
2052 		void __user *buffer, size_t *lenp,
2053 		loff_t *ppos);
2054 
2055 #ifdef CONFIG_SCHED_AUTOGROUP
2056 extern unsigned int sysctl_sched_autogroup_enabled;
2057 
2058 extern void sched_autogroup_create_attach(struct task_struct *p);
2059 extern void sched_autogroup_detach(struct task_struct *p);
2060 extern void sched_autogroup_fork(struct signal_struct *sig);
2061 extern void sched_autogroup_exit(struct signal_struct *sig);
2062 #ifdef CONFIG_PROC_FS
2063 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2064 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2065 #endif
2066 #else
2067 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2068 static inline void sched_autogroup_detach(struct task_struct *p) { }
2069 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2070 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2071 #endif
2072 
2073 #ifdef CONFIG_CFS_BANDWIDTH
2074 extern unsigned int sysctl_sched_cfs_bandwidth_slice;
2075 #endif
2076 
2077 #ifdef CONFIG_RT_MUTEXES
2078 extern int rt_mutex_getprio(struct task_struct *p);
2079 extern void rt_mutex_setprio(struct task_struct *p, int prio);
2080 extern void rt_mutex_adjust_pi(struct task_struct *p);
2081 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2082 {
2083 	return tsk->pi_blocked_on != NULL;
2084 }
2085 #else
2086 static inline int rt_mutex_getprio(struct task_struct *p)
2087 {
2088 	return p->normal_prio;
2089 }
2090 # define rt_mutex_adjust_pi(p)		do { } while (0)
2091 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2092 {
2093 	return false;
2094 }
2095 #endif
2096 
2097 extern bool yield_to(struct task_struct *p, bool preempt);
2098 extern void set_user_nice(struct task_struct *p, long nice);
2099 extern int task_prio(const struct task_struct *p);
2100 extern int task_nice(const struct task_struct *p);
2101 extern int can_nice(const struct task_struct *p, const int nice);
2102 extern int task_curr(const struct task_struct *p);
2103 extern int idle_cpu(int cpu);
2104 extern int sched_setscheduler(struct task_struct *, int,
2105 			      const struct sched_param *);
2106 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2107 				      const struct sched_param *);
2108 extern struct task_struct *idle_task(int cpu);
2109 /**
2110  * is_idle_task - is the specified task an idle task?
2111  * @p: the task in question.
2112  */
2113 static inline bool is_idle_task(const struct task_struct *p)
2114 {
2115 	return p->pid == 0;
2116 }
2117 extern struct task_struct *curr_task(int cpu);
2118 extern void set_curr_task(int cpu, struct task_struct *p);
2119 
2120 void yield(void);
2121 
2122 /*
2123  * The default (Linux) execution domain.
2124  */
2125 extern struct exec_domain	default_exec_domain;
2126 
2127 union thread_union {
2128 	struct thread_info thread_info;
2129 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2130 };
2131 
2132 #ifndef __HAVE_ARCH_KSTACK_END
2133 static inline int kstack_end(void *addr)
2134 {
2135 	/* Reliable end of stack detection:
2136 	 * Some APM bios versions misalign the stack
2137 	 */
2138 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2139 }
2140 #endif
2141 
2142 extern union thread_union init_thread_union;
2143 extern struct task_struct init_task;
2144 
2145 extern struct   mm_struct init_mm;
2146 
2147 extern struct pid_namespace init_pid_ns;
2148 
2149 /*
2150  * find a task by one of its numerical ids
2151  *
2152  * find_task_by_pid_ns():
2153  *      finds a task by its pid in the specified namespace
2154  * find_task_by_vpid():
2155  *      finds a task by its virtual pid
2156  *
2157  * see also find_vpid() etc in include/linux/pid.h
2158  */
2159 
2160 extern struct task_struct *find_task_by_vpid(pid_t nr);
2161 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2162 		struct pid_namespace *ns);
2163 
2164 extern void __set_special_pids(struct pid *pid);
2165 
2166 /* per-UID process charging. */
2167 extern struct user_struct * alloc_uid(kuid_t);
2168 static inline struct user_struct *get_uid(struct user_struct *u)
2169 {
2170 	atomic_inc(&u->__count);
2171 	return u;
2172 }
2173 extern void free_uid(struct user_struct *);
2174 
2175 #include <asm/current.h>
2176 
2177 extern void xtime_update(unsigned long ticks);
2178 
2179 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2180 extern int wake_up_process(struct task_struct *tsk);
2181 extern void wake_up_new_task(struct task_struct *tsk);
2182 #ifdef CONFIG_SMP
2183  extern void kick_process(struct task_struct *tsk);
2184 #else
2185  static inline void kick_process(struct task_struct *tsk) { }
2186 #endif
2187 extern void sched_fork(struct task_struct *p);
2188 extern void sched_dead(struct task_struct *p);
2189 
2190 extern void proc_caches_init(void);
2191 extern void flush_signals(struct task_struct *);
2192 extern void __flush_signals(struct task_struct *);
2193 extern void ignore_signals(struct task_struct *);
2194 extern void flush_signal_handlers(struct task_struct *, int force_default);
2195 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2196 
2197 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2198 {
2199 	unsigned long flags;
2200 	int ret;
2201 
2202 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2203 	ret = dequeue_signal(tsk, mask, info);
2204 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2205 
2206 	return ret;
2207 }
2208 
2209 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2210 			      sigset_t *mask);
2211 extern void unblock_all_signals(void);
2212 extern void release_task(struct task_struct * p);
2213 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2214 extern int force_sigsegv(int, struct task_struct *);
2215 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2216 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2217 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2218 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2219 				const struct cred *, u32);
2220 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2221 extern int kill_pid(struct pid *pid, int sig, int priv);
2222 extern int kill_proc_info(int, struct siginfo *, pid_t);
2223 extern __must_check bool do_notify_parent(struct task_struct *, int);
2224 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2225 extern void force_sig(int, struct task_struct *);
2226 extern int send_sig(int, struct task_struct *, int);
2227 extern int zap_other_threads(struct task_struct *p);
2228 extern struct sigqueue *sigqueue_alloc(void);
2229 extern void sigqueue_free(struct sigqueue *);
2230 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2231 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2232 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2233 
2234 static inline void restore_saved_sigmask(void)
2235 {
2236 	if (test_and_clear_restore_sigmask())
2237 		__set_current_blocked(&current->saved_sigmask);
2238 }
2239 
2240 static inline sigset_t *sigmask_to_save(void)
2241 {
2242 	sigset_t *res = &current->blocked;
2243 	if (unlikely(test_restore_sigmask()))
2244 		res = &current->saved_sigmask;
2245 	return res;
2246 }
2247 
2248 static inline int kill_cad_pid(int sig, int priv)
2249 {
2250 	return kill_pid(cad_pid, sig, priv);
2251 }
2252 
2253 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2254 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2255 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2256 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2257 
2258 /*
2259  * True if we are on the alternate signal stack.
2260  */
2261 static inline int on_sig_stack(unsigned long sp)
2262 {
2263 #ifdef CONFIG_STACK_GROWSUP
2264 	return sp >= current->sas_ss_sp &&
2265 		sp - current->sas_ss_sp < current->sas_ss_size;
2266 #else
2267 	return sp > current->sas_ss_sp &&
2268 		sp - current->sas_ss_sp <= current->sas_ss_size;
2269 #endif
2270 }
2271 
2272 static inline int sas_ss_flags(unsigned long sp)
2273 {
2274 	return (current->sas_ss_size == 0 ? SS_DISABLE
2275 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2276 }
2277 
2278 /*
2279  * Routines for handling mm_structs
2280  */
2281 extern struct mm_struct * mm_alloc(void);
2282 
2283 /* mmdrop drops the mm and the page tables */
2284 extern void __mmdrop(struct mm_struct *);
2285 static inline void mmdrop(struct mm_struct * mm)
2286 {
2287 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2288 		__mmdrop(mm);
2289 }
2290 
2291 /* mmput gets rid of the mappings and all user-space */
2292 extern void mmput(struct mm_struct *);
2293 /* Grab a reference to a task's mm, if it is not already going away */
2294 extern struct mm_struct *get_task_mm(struct task_struct *task);
2295 /*
2296  * Grab a reference to a task's mm, if it is not already going away
2297  * and ptrace_may_access with the mode parameter passed to it
2298  * succeeds.
2299  */
2300 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2301 /* Remove the current tasks stale references to the old mm_struct */
2302 extern void mm_release(struct task_struct *, struct mm_struct *);
2303 /* Allocate a new mm structure and copy contents from tsk->mm */
2304 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2305 
2306 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2307 			struct task_struct *, struct pt_regs *);
2308 extern void flush_thread(void);
2309 extern void exit_thread(void);
2310 
2311 extern void exit_files(struct task_struct *);
2312 extern void __cleanup_sighand(struct sighand_struct *);
2313 
2314 extern void exit_itimers(struct signal_struct *);
2315 extern void flush_itimer_signals(void);
2316 
2317 extern void do_group_exit(int);
2318 
2319 extern void daemonize(const char *, ...);
2320 extern int allow_signal(int);
2321 extern int disallow_signal(int);
2322 
2323 extern int do_execve(const char *,
2324 		     const char __user * const __user *,
2325 		     const char __user * const __user *, struct pt_regs *);
2326 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2327 struct task_struct *fork_idle(int);
2328 
2329 extern void set_task_comm(struct task_struct *tsk, char *from);
2330 extern char *get_task_comm(char *to, struct task_struct *tsk);
2331 
2332 #ifdef CONFIG_SMP
2333 void scheduler_ipi(void);
2334 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2335 #else
2336 static inline void scheduler_ipi(void) { }
2337 static inline unsigned long wait_task_inactive(struct task_struct *p,
2338 					       long match_state)
2339 {
2340 	return 1;
2341 }
2342 #endif
2343 
2344 #define next_task(p) \
2345 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2346 
2347 #define for_each_process(p) \
2348 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2349 
2350 extern bool current_is_single_threaded(void);
2351 
2352 /*
2353  * Careful: do_each_thread/while_each_thread is a double loop so
2354  *          'break' will not work as expected - use goto instead.
2355  */
2356 #define do_each_thread(g, t) \
2357 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2358 
2359 #define while_each_thread(g, t) \
2360 	while ((t = next_thread(t)) != g)
2361 
2362 static inline int get_nr_threads(struct task_struct *tsk)
2363 {
2364 	return tsk->signal->nr_threads;
2365 }
2366 
2367 static inline bool thread_group_leader(struct task_struct *p)
2368 {
2369 	return p->exit_signal >= 0;
2370 }
2371 
2372 /* Do to the insanities of de_thread it is possible for a process
2373  * to have the pid of the thread group leader without actually being
2374  * the thread group leader.  For iteration through the pids in proc
2375  * all we care about is that we have a task with the appropriate
2376  * pid, we don't actually care if we have the right task.
2377  */
2378 static inline int has_group_leader_pid(struct task_struct *p)
2379 {
2380 	return p->pid == p->tgid;
2381 }
2382 
2383 static inline
2384 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2385 {
2386 	return p1->tgid == p2->tgid;
2387 }
2388 
2389 static inline struct task_struct *next_thread(const struct task_struct *p)
2390 {
2391 	return list_entry_rcu(p->thread_group.next,
2392 			      struct task_struct, thread_group);
2393 }
2394 
2395 static inline int thread_group_empty(struct task_struct *p)
2396 {
2397 	return list_empty(&p->thread_group);
2398 }
2399 
2400 #define delay_group_leader(p) \
2401 		(thread_group_leader(p) && !thread_group_empty(p))
2402 
2403 /*
2404  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2405  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2406  * pins the final release of task.io_context.  Also protects ->cpuset and
2407  * ->cgroup.subsys[]. And ->vfork_done.
2408  *
2409  * Nests both inside and outside of read_lock(&tasklist_lock).
2410  * It must not be nested with write_lock_irq(&tasklist_lock),
2411  * neither inside nor outside.
2412  */
2413 static inline void task_lock(struct task_struct *p)
2414 {
2415 	spin_lock(&p->alloc_lock);
2416 }
2417 
2418 static inline void task_unlock(struct task_struct *p)
2419 {
2420 	spin_unlock(&p->alloc_lock);
2421 }
2422 
2423 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2424 							unsigned long *flags);
2425 
2426 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2427 						       unsigned long *flags)
2428 {
2429 	struct sighand_struct *ret;
2430 
2431 	ret = __lock_task_sighand(tsk, flags);
2432 	(void)__cond_lock(&tsk->sighand->siglock, ret);
2433 	return ret;
2434 }
2435 
2436 static inline void unlock_task_sighand(struct task_struct *tsk,
2437 						unsigned long *flags)
2438 {
2439 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2440 }
2441 
2442 #ifdef CONFIG_CGROUPS
2443 static inline void threadgroup_change_begin(struct task_struct *tsk)
2444 {
2445 	down_read(&tsk->signal->group_rwsem);
2446 }
2447 static inline void threadgroup_change_end(struct task_struct *tsk)
2448 {
2449 	up_read(&tsk->signal->group_rwsem);
2450 }
2451 
2452 /**
2453  * threadgroup_lock - lock threadgroup
2454  * @tsk: member task of the threadgroup to lock
2455  *
2456  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2457  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2458  * perform exec.  This is useful for cases where the threadgroup needs to
2459  * stay stable across blockable operations.
2460  *
2461  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2462  * synchronization.  While held, no new task will be added to threadgroup
2463  * and no existing live task will have its PF_EXITING set.
2464  *
2465  * During exec, a task goes and puts its thread group through unusual
2466  * changes.  After de-threading, exclusive access is assumed to resources
2467  * which are usually shared by tasks in the same group - e.g. sighand may
2468  * be replaced with a new one.  Also, the exec'ing task takes over group
2469  * leader role including its pid.  Exclude these changes while locked by
2470  * grabbing cred_guard_mutex which is used to synchronize exec path.
2471  */
2472 static inline void threadgroup_lock(struct task_struct *tsk)
2473 {
2474 	/*
2475 	 * exec uses exit for de-threading nesting group_rwsem inside
2476 	 * cred_guard_mutex. Grab cred_guard_mutex first.
2477 	 */
2478 	mutex_lock(&tsk->signal->cred_guard_mutex);
2479 	down_write(&tsk->signal->group_rwsem);
2480 }
2481 
2482 /**
2483  * threadgroup_unlock - unlock threadgroup
2484  * @tsk: member task of the threadgroup to unlock
2485  *
2486  * Reverse threadgroup_lock().
2487  */
2488 static inline void threadgroup_unlock(struct task_struct *tsk)
2489 {
2490 	up_write(&tsk->signal->group_rwsem);
2491 	mutex_unlock(&tsk->signal->cred_guard_mutex);
2492 }
2493 #else
2494 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2495 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2496 static inline void threadgroup_lock(struct task_struct *tsk) {}
2497 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2498 #endif
2499 
2500 #ifndef __HAVE_THREAD_FUNCTIONS
2501 
2502 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2503 #define task_stack_page(task)	((task)->stack)
2504 
2505 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2506 {
2507 	*task_thread_info(p) = *task_thread_info(org);
2508 	task_thread_info(p)->task = p;
2509 }
2510 
2511 static inline unsigned long *end_of_stack(struct task_struct *p)
2512 {
2513 	return (unsigned long *)(task_thread_info(p) + 1);
2514 }
2515 
2516 #endif
2517 
2518 static inline int object_is_on_stack(void *obj)
2519 {
2520 	void *stack = task_stack_page(current);
2521 
2522 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2523 }
2524 
2525 extern void thread_info_cache_init(void);
2526 
2527 #ifdef CONFIG_DEBUG_STACK_USAGE
2528 static inline unsigned long stack_not_used(struct task_struct *p)
2529 {
2530 	unsigned long *n = end_of_stack(p);
2531 
2532 	do { 	/* Skip over canary */
2533 		n++;
2534 	} while (!*n);
2535 
2536 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2537 }
2538 #endif
2539 
2540 /* set thread flags in other task's structures
2541  * - see asm/thread_info.h for TIF_xxxx flags available
2542  */
2543 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2544 {
2545 	set_ti_thread_flag(task_thread_info(tsk), flag);
2546 }
2547 
2548 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2549 {
2550 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2551 }
2552 
2553 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2554 {
2555 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2556 }
2557 
2558 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2559 {
2560 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2561 }
2562 
2563 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2564 {
2565 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2566 }
2567 
2568 static inline void set_tsk_need_resched(struct task_struct *tsk)
2569 {
2570 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2571 }
2572 
2573 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2574 {
2575 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2576 }
2577 
2578 static inline int test_tsk_need_resched(struct task_struct *tsk)
2579 {
2580 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2581 }
2582 
2583 static inline int restart_syscall(void)
2584 {
2585 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2586 	return -ERESTARTNOINTR;
2587 }
2588 
2589 static inline int signal_pending(struct task_struct *p)
2590 {
2591 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2592 }
2593 
2594 static inline int __fatal_signal_pending(struct task_struct *p)
2595 {
2596 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2597 }
2598 
2599 static inline int fatal_signal_pending(struct task_struct *p)
2600 {
2601 	return signal_pending(p) && __fatal_signal_pending(p);
2602 }
2603 
2604 static inline int signal_pending_state(long state, struct task_struct *p)
2605 {
2606 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2607 		return 0;
2608 	if (!signal_pending(p))
2609 		return 0;
2610 
2611 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2612 }
2613 
2614 static inline int need_resched(void)
2615 {
2616 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2617 }
2618 
2619 /*
2620  * cond_resched() and cond_resched_lock(): latency reduction via
2621  * explicit rescheduling in places that are safe. The return
2622  * value indicates whether a reschedule was done in fact.
2623  * cond_resched_lock() will drop the spinlock before scheduling,
2624  * cond_resched_softirq() will enable bhs before scheduling.
2625  */
2626 extern int _cond_resched(void);
2627 
2628 #define cond_resched() ({			\
2629 	__might_sleep(__FILE__, __LINE__, 0);	\
2630 	_cond_resched();			\
2631 })
2632 
2633 extern int __cond_resched_lock(spinlock_t *lock);
2634 
2635 #ifdef CONFIG_PREEMPT_COUNT
2636 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2637 #else
2638 #define PREEMPT_LOCK_OFFSET	0
2639 #endif
2640 
2641 #define cond_resched_lock(lock) ({				\
2642 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2643 	__cond_resched_lock(lock);				\
2644 })
2645 
2646 extern int __cond_resched_softirq(void);
2647 
2648 #define cond_resched_softirq() ({					\
2649 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2650 	__cond_resched_softirq();					\
2651 })
2652 
2653 /*
2654  * Does a critical section need to be broken due to another
2655  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2656  * but a general need for low latency)
2657  */
2658 static inline int spin_needbreak(spinlock_t *lock)
2659 {
2660 #ifdef CONFIG_PREEMPT
2661 	return spin_is_contended(lock);
2662 #else
2663 	return 0;
2664 #endif
2665 }
2666 
2667 /*
2668  * Thread group CPU time accounting.
2669  */
2670 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2671 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2672 
2673 static inline void thread_group_cputime_init(struct signal_struct *sig)
2674 {
2675 	raw_spin_lock_init(&sig->cputimer.lock);
2676 }
2677 
2678 /*
2679  * Reevaluate whether the task has signals pending delivery.
2680  * Wake the task if so.
2681  * This is required every time the blocked sigset_t changes.
2682  * callers must hold sighand->siglock.
2683  */
2684 extern void recalc_sigpending_and_wake(struct task_struct *t);
2685 extern void recalc_sigpending(void);
2686 
2687 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2688 
2689 /*
2690  * Wrappers for p->thread_info->cpu access. No-op on UP.
2691  */
2692 #ifdef CONFIG_SMP
2693 
2694 static inline unsigned int task_cpu(const struct task_struct *p)
2695 {
2696 	return task_thread_info(p)->cpu;
2697 }
2698 
2699 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2700 
2701 #else
2702 
2703 static inline unsigned int task_cpu(const struct task_struct *p)
2704 {
2705 	return 0;
2706 }
2707 
2708 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2709 {
2710 }
2711 
2712 #endif /* CONFIG_SMP */
2713 
2714 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2715 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2716 
2717 extern void normalize_rt_tasks(void);
2718 
2719 #ifdef CONFIG_CGROUP_SCHED
2720 
2721 extern struct task_group root_task_group;
2722 
2723 extern struct task_group *sched_create_group(struct task_group *parent);
2724 extern void sched_destroy_group(struct task_group *tg);
2725 extern void sched_move_task(struct task_struct *tsk);
2726 #ifdef CONFIG_FAIR_GROUP_SCHED
2727 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2728 extern unsigned long sched_group_shares(struct task_group *tg);
2729 #endif
2730 #ifdef CONFIG_RT_GROUP_SCHED
2731 extern int sched_group_set_rt_runtime(struct task_group *tg,
2732 				      long rt_runtime_us);
2733 extern long sched_group_rt_runtime(struct task_group *tg);
2734 extern int sched_group_set_rt_period(struct task_group *tg,
2735 				      long rt_period_us);
2736 extern long sched_group_rt_period(struct task_group *tg);
2737 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2738 #endif
2739 #endif /* CONFIG_CGROUP_SCHED */
2740 
2741 extern int task_can_switch_user(struct user_struct *up,
2742 					struct task_struct *tsk);
2743 
2744 #ifdef CONFIG_TASK_XACCT
2745 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2746 {
2747 	tsk->ioac.rchar += amt;
2748 }
2749 
2750 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2751 {
2752 	tsk->ioac.wchar += amt;
2753 }
2754 
2755 static inline void inc_syscr(struct task_struct *tsk)
2756 {
2757 	tsk->ioac.syscr++;
2758 }
2759 
2760 static inline void inc_syscw(struct task_struct *tsk)
2761 {
2762 	tsk->ioac.syscw++;
2763 }
2764 #else
2765 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2766 {
2767 }
2768 
2769 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2770 {
2771 }
2772 
2773 static inline void inc_syscr(struct task_struct *tsk)
2774 {
2775 }
2776 
2777 static inline void inc_syscw(struct task_struct *tsk)
2778 {
2779 }
2780 #endif
2781 
2782 #ifndef TASK_SIZE_OF
2783 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2784 #endif
2785 
2786 #ifdef CONFIG_MM_OWNER
2787 extern void mm_update_next_owner(struct mm_struct *mm);
2788 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2789 #else
2790 static inline void mm_update_next_owner(struct mm_struct *mm)
2791 {
2792 }
2793 
2794 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2795 {
2796 }
2797 #endif /* CONFIG_MM_OWNER */
2798 
2799 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2800 		unsigned int limit)
2801 {
2802 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2803 }
2804 
2805 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2806 		unsigned int limit)
2807 {
2808 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2809 }
2810 
2811 static inline unsigned long rlimit(unsigned int limit)
2812 {
2813 	return task_rlimit(current, limit);
2814 }
2815 
2816 static inline unsigned long rlimit_max(unsigned int limit)
2817 {
2818 	return task_rlimit_max(current, limit);
2819 }
2820 
2821 #endif /* __KERNEL__ */
2822 
2823 #endif
2824