xref: /linux/include/linux/sched.h (revision e26207a3819684e9b4450a2d30bdd065fa92d9c7)
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3 
4 /*
5  * cloning flags:
6  */
7 #define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
8 #define CLONE_VM	0x00000100	/* set if VM shared between processes */
9 #define CLONE_FS	0x00000200	/* set if fs info shared between processes */
10 #define CLONE_FILES	0x00000400	/* set if open files shared between processes */
11 #define CLONE_SIGHAND	0x00000800	/* set if signal handlers and blocked signals shared */
12 #define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
13 #define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */
14 #define CLONE_PARENT	0x00008000	/* set if we want to have the same parent as the cloner */
15 #define CLONE_THREAD	0x00010000	/* Same thread group? */
16 #define CLONE_NEWNS	0x00020000	/* New namespace group? */
17 #define CLONE_SYSVSEM	0x00040000	/* share system V SEM_UNDO semantics */
18 #define CLONE_SETTLS	0x00080000	/* create a new TLS for the child */
19 #define CLONE_PARENT_SETTID	0x00100000	/* set the TID in the parent */
20 #define CLONE_CHILD_CLEARTID	0x00200000	/* clear the TID in the child */
21 #define CLONE_DETACHED		0x00400000	/* Unused, ignored */
22 #define CLONE_UNTRACED		0x00800000	/* set if the tracing process can't force CLONE_PTRACE on this clone */
23 #define CLONE_CHILD_SETTID	0x01000000	/* set the TID in the child */
24 #define CLONE_STOPPED		0x02000000	/* Start in stopped state */
25 #define CLONE_NEWUTS		0x04000000	/* New utsname group? */
26 #define CLONE_NEWIPC		0x08000000	/* New ipcs */
27 #define CLONE_NEWUSER		0x10000000	/* New user namespace */
28 #define CLONE_NEWPID		0x20000000	/* New pid namespace */
29 #define CLONE_NEWNET		0x40000000	/* New network namespace */
30 #define CLONE_IO		0x80000000	/* Clone io context */
31 
32 /*
33  * Scheduling policies
34  */
35 #define SCHED_NORMAL		0
36 #define SCHED_FIFO		1
37 #define SCHED_RR		2
38 #define SCHED_BATCH		3
39 /* SCHED_ISO: reserved but not implemented yet */
40 #define SCHED_IDLE		5
41 /* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
42 #define SCHED_RESET_ON_FORK     0x40000000
43 
44 #ifdef __KERNEL__
45 
46 struct sched_param {
47 	int sched_priority;
48 };
49 
50 #include <asm/param.h>	/* for HZ */
51 
52 #include <linux/capability.h>
53 #include <linux/threads.h>
54 #include <linux/kernel.h>
55 #include <linux/types.h>
56 #include <linux/timex.h>
57 #include <linux/jiffies.h>
58 #include <linux/rbtree.h>
59 #include <linux/thread_info.h>
60 #include <linux/cpumask.h>
61 #include <linux/errno.h>
62 #include <linux/nodemask.h>
63 #include <linux/mm_types.h>
64 
65 #include <asm/system.h>
66 #include <asm/page.h>
67 #include <asm/ptrace.h>
68 #include <asm/cputime.h>
69 
70 #include <linux/smp.h>
71 #include <linux/sem.h>
72 #include <linux/signal.h>
73 #include <linux/path.h>
74 #include <linux/compiler.h>
75 #include <linux/completion.h>
76 #include <linux/pid.h>
77 #include <linux/percpu.h>
78 #include <linux/topology.h>
79 #include <linux/proportions.h>
80 #include <linux/seccomp.h>
81 #include <linux/rcupdate.h>
82 #include <linux/rculist.h>
83 #include <linux/rtmutex.h>
84 
85 #include <linux/time.h>
86 #include <linux/param.h>
87 #include <linux/resource.h>
88 #include <linux/timer.h>
89 #include <linux/hrtimer.h>
90 #include <linux/task_io_accounting.h>
91 #include <linux/kobject.h>
92 #include <linux/latencytop.h>
93 #include <linux/cred.h>
94 
95 #include <asm/processor.h>
96 
97 struct exec_domain;
98 struct futex_pi_state;
99 struct robust_list_head;
100 struct bio;
101 struct fs_struct;
102 struct bts_context;
103 struct perf_event_context;
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(void);
144 extern unsigned long this_cpu_load(void);
145 
146 
147 extern void calc_global_load(void);
148 
149 extern unsigned long get_parent_ip(unsigned long addr);
150 
151 struct seq_file;
152 struct cfs_rq;
153 struct task_group;
154 #ifdef CONFIG_SCHED_DEBUG
155 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
156 extern void proc_sched_set_task(struct task_struct *p);
157 extern void
158 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
159 #else
160 static inline void
161 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
162 {
163 }
164 static inline void proc_sched_set_task(struct task_struct *p)
165 {
166 }
167 static inline void
168 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
169 {
170 }
171 #endif
172 
173 /*
174  * Task state bitmask. NOTE! These bits are also
175  * encoded in fs/proc/array.c: get_task_state().
176  *
177  * We have two separate sets of flags: task->state
178  * is about runnability, while task->exit_state are
179  * about the task exiting. Confusing, but this way
180  * modifying one set can't modify the other one by
181  * mistake.
182  */
183 #define TASK_RUNNING		0
184 #define TASK_INTERRUPTIBLE	1
185 #define TASK_UNINTERRUPTIBLE	2
186 #define __TASK_STOPPED		4
187 #define __TASK_TRACED		8
188 /* in tsk->exit_state */
189 #define EXIT_ZOMBIE		16
190 #define EXIT_DEAD		32
191 /* in tsk->state again */
192 #define TASK_DEAD		64
193 #define TASK_WAKEKILL		128
194 #define TASK_WAKING		256
195 #define TASK_STATE_MAX		512
196 
197 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
198 
199 extern char ___assert_task_state[1 - 2*!!(
200 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
201 
202 /* Convenience macros for the sake of set_task_state */
203 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
204 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
205 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
206 
207 /* Convenience macros for the sake of wake_up */
208 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
209 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
210 
211 /* get_task_state() */
212 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
213 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
214 				 __TASK_TRACED)
215 
216 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
217 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
218 #define task_is_stopped_or_traced(task)	\
219 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
220 #define task_contributes_to_load(task)	\
221 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
222 				 (task->flags & PF_FREEZING) == 0)
223 
224 #define __set_task_state(tsk, state_value)		\
225 	do { (tsk)->state = (state_value); } while (0)
226 #define set_task_state(tsk, state_value)		\
227 	set_mb((tsk)->state, (state_value))
228 
229 /*
230  * set_current_state() includes a barrier so that the write of current->state
231  * is correctly serialised wrt the caller's subsequent test of whether to
232  * actually sleep:
233  *
234  *	set_current_state(TASK_UNINTERRUPTIBLE);
235  *	if (do_i_need_to_sleep())
236  *		schedule();
237  *
238  * If the caller does not need such serialisation then use __set_current_state()
239  */
240 #define __set_current_state(state_value)			\
241 	do { current->state = (state_value); } while (0)
242 #define set_current_state(state_value)		\
243 	set_mb(current->state, (state_value))
244 
245 /* Task command name length */
246 #define TASK_COMM_LEN 16
247 
248 #include <linux/spinlock.h>
249 
250 /*
251  * This serializes "schedule()" and also protects
252  * the run-queue from deletions/modifications (but
253  * _adding_ to the beginning of the run-queue has
254  * a separate lock).
255  */
256 extern rwlock_t tasklist_lock;
257 extern spinlock_t mmlist_lock;
258 
259 struct task_struct;
260 
261 extern void sched_init(void);
262 extern void sched_init_smp(void);
263 extern asmlinkage void schedule_tail(struct task_struct *prev);
264 extern void init_idle(struct task_struct *idle, int cpu);
265 extern void init_idle_bootup_task(struct task_struct *idle);
266 
267 extern int runqueue_is_locked(int cpu);
268 extern void task_rq_unlock_wait(struct task_struct *p);
269 
270 extern cpumask_var_t nohz_cpu_mask;
271 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
272 extern int select_nohz_load_balancer(int cpu);
273 extern int get_nohz_load_balancer(void);
274 #else
275 static inline int select_nohz_load_balancer(int cpu)
276 {
277 	return 0;
278 }
279 #endif
280 
281 /*
282  * Only dump TASK_* tasks. (0 for all tasks)
283  */
284 extern void show_state_filter(unsigned long state_filter);
285 
286 static inline void show_state(void)
287 {
288 	show_state_filter(0);
289 }
290 
291 extern void show_regs(struct pt_regs *);
292 
293 /*
294  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
295  * task), SP is the stack pointer of the first frame that should be shown in the back
296  * trace (or NULL if the entire call-chain of the task should be shown).
297  */
298 extern void show_stack(struct task_struct *task, unsigned long *sp);
299 
300 void io_schedule(void);
301 long io_schedule_timeout(long timeout);
302 
303 extern void cpu_init (void);
304 extern void trap_init(void);
305 extern void update_process_times(int user);
306 extern void scheduler_tick(void);
307 
308 extern void sched_show_task(struct task_struct *p);
309 
310 #ifdef CONFIG_DETECT_SOFTLOCKUP
311 extern void softlockup_tick(void);
312 extern void touch_softlockup_watchdog(void);
313 extern void touch_all_softlockup_watchdogs(void);
314 extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
315 				    void __user *buffer,
316 				    size_t *lenp, loff_t *ppos);
317 extern unsigned int  softlockup_panic;
318 extern int softlockup_thresh;
319 #else
320 static inline void softlockup_tick(void)
321 {
322 }
323 static inline void touch_softlockup_watchdog(void)
324 {
325 }
326 static inline void touch_all_softlockup_watchdogs(void)
327 {
328 }
329 #endif
330 
331 #ifdef CONFIG_DETECT_HUNG_TASK
332 extern unsigned int  sysctl_hung_task_panic;
333 extern unsigned long sysctl_hung_task_check_count;
334 extern unsigned long sysctl_hung_task_timeout_secs;
335 extern unsigned long sysctl_hung_task_warnings;
336 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
337 					 void __user *buffer,
338 					 size_t *lenp, loff_t *ppos);
339 #endif
340 
341 /* Attach to any functions which should be ignored in wchan output. */
342 #define __sched		__attribute__((__section__(".sched.text")))
343 
344 /* Linker adds these: start and end of __sched functions */
345 extern char __sched_text_start[], __sched_text_end[];
346 
347 /* Is this address in the __sched functions? */
348 extern int in_sched_functions(unsigned long addr);
349 
350 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
351 extern signed long schedule_timeout(signed long timeout);
352 extern signed long schedule_timeout_interruptible(signed long timeout);
353 extern signed long schedule_timeout_killable(signed long timeout);
354 extern signed long schedule_timeout_uninterruptible(signed long timeout);
355 asmlinkage void schedule(void);
356 extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
357 
358 struct nsproxy;
359 struct user_namespace;
360 
361 /*
362  * Default maximum number of active map areas, this limits the number of vmas
363  * per mm struct. Users can overwrite this number by sysctl but there is a
364  * problem.
365  *
366  * When a program's coredump is generated as ELF format, a section is created
367  * per a vma. In ELF, the number of sections is represented in unsigned short.
368  * This means the number of sections should be smaller than 65535 at coredump.
369  * Because the kernel adds some informative sections to a image of program at
370  * generating coredump, we need some margin. The number of extra sections is
371  * 1-3 now and depends on arch. We use "5" as safe margin, here.
372  */
373 #define MAPCOUNT_ELF_CORE_MARGIN	(5)
374 #define DEFAULT_MAX_MAP_COUNT	(USHORT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
375 
376 extern int sysctl_max_map_count;
377 
378 #include <linux/aio.h>
379 
380 #ifdef CONFIG_MMU
381 extern void arch_pick_mmap_layout(struct mm_struct *mm);
382 extern unsigned long
383 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
384 		       unsigned long, unsigned long);
385 extern unsigned long
386 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
387 			  unsigned long len, unsigned long pgoff,
388 			  unsigned long flags);
389 extern void arch_unmap_area(struct mm_struct *, unsigned long);
390 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
391 #else
392 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
393 #endif
394 
395 #if USE_SPLIT_PTLOCKS
396 /*
397  * The mm counters are not protected by its page_table_lock,
398  * so must be incremented atomically.
399  */
400 #define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
401 #define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
402 #define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
403 #define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
404 #define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
405 
406 #else  /* !USE_SPLIT_PTLOCKS */
407 /*
408  * The mm counters are protected by its page_table_lock,
409  * so can be incremented directly.
410  */
411 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
412 #define get_mm_counter(mm, member) ((mm)->_##member)
413 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
414 #define inc_mm_counter(mm, member) (mm)->_##member++
415 #define dec_mm_counter(mm, member) (mm)->_##member--
416 
417 #endif /* !USE_SPLIT_PTLOCKS */
418 
419 #define get_mm_rss(mm)					\
420 	(get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
421 #define update_hiwater_rss(mm)	do {			\
422 	unsigned long _rss = get_mm_rss(mm);		\
423 	if ((mm)->hiwater_rss < _rss)			\
424 		(mm)->hiwater_rss = _rss;		\
425 } while (0)
426 #define update_hiwater_vm(mm)	do {			\
427 	if ((mm)->hiwater_vm < (mm)->total_vm)		\
428 		(mm)->hiwater_vm = (mm)->total_vm;	\
429 } while (0)
430 
431 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
432 {
433 	return max(mm->hiwater_rss, get_mm_rss(mm));
434 }
435 
436 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
437 					 struct mm_struct *mm)
438 {
439 	unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
440 
441 	if (*maxrss < hiwater_rss)
442 		*maxrss = hiwater_rss;
443 }
444 
445 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
446 {
447 	return max(mm->hiwater_vm, mm->total_vm);
448 }
449 
450 extern void set_dumpable(struct mm_struct *mm, int value);
451 extern int get_dumpable(struct mm_struct *mm);
452 
453 /* mm flags */
454 /* dumpable bits */
455 #define MMF_DUMPABLE      0  /* core dump is permitted */
456 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
457 
458 #define MMF_DUMPABLE_BITS 2
459 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
460 
461 /* coredump filter bits */
462 #define MMF_DUMP_ANON_PRIVATE	2
463 #define MMF_DUMP_ANON_SHARED	3
464 #define MMF_DUMP_MAPPED_PRIVATE	4
465 #define MMF_DUMP_MAPPED_SHARED	5
466 #define MMF_DUMP_ELF_HEADERS	6
467 #define MMF_DUMP_HUGETLB_PRIVATE 7
468 #define MMF_DUMP_HUGETLB_SHARED  8
469 
470 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
471 #define MMF_DUMP_FILTER_BITS	7
472 #define MMF_DUMP_FILTER_MASK \
473 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
474 #define MMF_DUMP_FILTER_DEFAULT \
475 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
476 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
477 
478 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
479 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
480 #else
481 # define MMF_DUMP_MASK_DEFAULT_ELF	0
482 #endif
483 					/* leave room for more dump flags */
484 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
485 
486 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
487 
488 struct sighand_struct {
489 	atomic_t		count;
490 	struct k_sigaction	action[_NSIG];
491 	spinlock_t		siglock;
492 	wait_queue_head_t	signalfd_wqh;
493 };
494 
495 struct pacct_struct {
496 	int			ac_flag;
497 	long			ac_exitcode;
498 	unsigned long		ac_mem;
499 	cputime_t		ac_utime, ac_stime;
500 	unsigned long		ac_minflt, ac_majflt;
501 };
502 
503 struct cpu_itimer {
504 	cputime_t expires;
505 	cputime_t incr;
506 	u32 error;
507 	u32 incr_error;
508 };
509 
510 /**
511  * struct task_cputime - collected CPU time counts
512  * @utime:		time spent in user mode, in &cputime_t units
513  * @stime:		time spent in kernel mode, in &cputime_t units
514  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
515  *
516  * This structure groups together three kinds of CPU time that are
517  * tracked for threads and thread groups.  Most things considering
518  * CPU time want to group these counts together and treat all three
519  * of them in parallel.
520  */
521 struct task_cputime {
522 	cputime_t utime;
523 	cputime_t stime;
524 	unsigned long long sum_exec_runtime;
525 };
526 /* Alternate field names when used to cache expirations. */
527 #define prof_exp	stime
528 #define virt_exp	utime
529 #define sched_exp	sum_exec_runtime
530 
531 #define INIT_CPUTIME	\
532 	(struct task_cputime) {					\
533 		.utime = cputime_zero,				\
534 		.stime = cputime_zero,				\
535 		.sum_exec_runtime = 0,				\
536 	}
537 
538 /*
539  * Disable preemption until the scheduler is running.
540  * Reset by start_kernel()->sched_init()->init_idle().
541  *
542  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
543  * before the scheduler is active -- see should_resched().
544  */
545 #define INIT_PREEMPT_COUNT	(1 + PREEMPT_ACTIVE)
546 
547 /**
548  * struct thread_group_cputimer - thread group interval timer counts
549  * @cputime:		thread group interval timers.
550  * @running:		non-zero when there are timers running and
551  * 			@cputime receives updates.
552  * @lock:		lock for fields in this struct.
553  *
554  * This structure contains the version of task_cputime, above, that is
555  * used for thread group CPU timer calculations.
556  */
557 struct thread_group_cputimer {
558 	struct task_cputime cputime;
559 	int running;
560 	spinlock_t lock;
561 };
562 
563 /*
564  * NOTE! "signal_struct" does not have it's own
565  * locking, because a shared signal_struct always
566  * implies a shared sighand_struct, so locking
567  * sighand_struct is always a proper superset of
568  * the locking of signal_struct.
569  */
570 struct signal_struct {
571 	atomic_t		count;
572 	atomic_t		live;
573 
574 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
575 
576 	/* current thread group signal load-balancing target: */
577 	struct task_struct	*curr_target;
578 
579 	/* shared signal handling: */
580 	struct sigpending	shared_pending;
581 
582 	/* thread group exit support */
583 	int			group_exit_code;
584 	/* overloaded:
585 	 * - notify group_exit_task when ->count is equal to notify_count
586 	 * - everyone except group_exit_task is stopped during signal delivery
587 	 *   of fatal signals, group_exit_task processes the signal.
588 	 */
589 	int			notify_count;
590 	struct task_struct	*group_exit_task;
591 
592 	/* thread group stop support, overloads group_exit_code too */
593 	int			group_stop_count;
594 	unsigned int		flags; /* see SIGNAL_* flags below */
595 
596 	/* POSIX.1b Interval Timers */
597 	struct list_head posix_timers;
598 
599 	/* ITIMER_REAL timer for the process */
600 	struct hrtimer real_timer;
601 	struct pid *leader_pid;
602 	ktime_t it_real_incr;
603 
604 	/*
605 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
606 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
607 	 * values are defined to 0 and 1 respectively
608 	 */
609 	struct cpu_itimer it[2];
610 
611 	/*
612 	 * Thread group totals for process CPU timers.
613 	 * See thread_group_cputimer(), et al, for details.
614 	 */
615 	struct thread_group_cputimer cputimer;
616 
617 	/* Earliest-expiration cache. */
618 	struct task_cputime cputime_expires;
619 
620 	struct list_head cpu_timers[3];
621 
622 	struct pid *tty_old_pgrp;
623 
624 	/* boolean value for session group leader */
625 	int leader;
626 
627 	struct tty_struct *tty; /* NULL if no tty */
628 
629 	/*
630 	 * Cumulative resource counters for dead threads in the group,
631 	 * and for reaped dead child processes forked by this group.
632 	 * Live threads maintain their own counters and add to these
633 	 * in __exit_signal, except for the group leader.
634 	 */
635 	cputime_t utime, stime, cutime, cstime;
636 	cputime_t gtime;
637 	cputime_t cgtime;
638 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
639 	cputime_t prev_utime, prev_stime;
640 #endif
641 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
642 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
643 	unsigned long inblock, oublock, cinblock, coublock;
644 	unsigned long maxrss, cmaxrss;
645 	struct task_io_accounting ioac;
646 
647 	/*
648 	 * Cumulative ns of schedule CPU time fo dead threads in the
649 	 * group, not including a zombie group leader, (This only differs
650 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
651 	 * other than jiffies.)
652 	 */
653 	unsigned long long sum_sched_runtime;
654 
655 	/*
656 	 * We don't bother to synchronize most readers of this at all,
657 	 * because there is no reader checking a limit that actually needs
658 	 * to get both rlim_cur and rlim_max atomically, and either one
659 	 * alone is a single word that can safely be read normally.
660 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
661 	 * protect this instead of the siglock, because they really
662 	 * have no need to disable irqs.
663 	 */
664 	struct rlimit rlim[RLIM_NLIMITS];
665 
666 #ifdef CONFIG_BSD_PROCESS_ACCT
667 	struct pacct_struct pacct;	/* per-process accounting information */
668 #endif
669 #ifdef CONFIG_TASKSTATS
670 	struct taskstats *stats;
671 #endif
672 #ifdef CONFIG_AUDIT
673 	unsigned audit_tty;
674 	struct tty_audit_buf *tty_audit_buf;
675 #endif
676 
677 	int oom_adj;	/* OOM kill score adjustment (bit shift) */
678 };
679 
680 /* Context switch must be unlocked if interrupts are to be enabled */
681 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
682 # define __ARCH_WANT_UNLOCKED_CTXSW
683 #endif
684 
685 /*
686  * Bits in flags field of signal_struct.
687  */
688 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
689 #define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
690 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
691 #define SIGNAL_GROUP_EXIT	0x00000008 /* 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_EPOLL
721 	atomic_t epoll_watches;	/* The number of file descriptors currently watched */
722 #endif
723 #ifdef CONFIG_POSIX_MQUEUE
724 	/* protected by mq_lock	*/
725 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
726 #endif
727 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
728 
729 #ifdef CONFIG_KEYS
730 	struct key *uid_keyring;	/* UID specific keyring */
731 	struct key *session_keyring;	/* UID's default session keyring */
732 #endif
733 
734 	/* Hash table maintenance information */
735 	struct hlist_node uidhash_node;
736 	uid_t uid;
737 	struct user_namespace *user_ns;
738 
739 #ifdef CONFIG_USER_SCHED
740 	struct task_group *tg;
741 #ifdef CONFIG_SYSFS
742 	struct kobject kobj;
743 	struct delayed_work work;
744 #endif
745 #endif
746 
747 #ifdef CONFIG_PERF_EVENTS
748 	atomic_long_t locked_vm;
749 #endif
750 };
751 
752 extern int uids_sysfs_init(void);
753 
754 extern struct user_struct *find_user(uid_t);
755 
756 extern struct user_struct root_user;
757 #define INIT_USER (&root_user)
758 
759 
760 struct backing_dev_info;
761 struct reclaim_state;
762 
763 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
764 struct sched_info {
765 	/* cumulative counters */
766 	unsigned long pcount;	      /* # of times run on this cpu */
767 	unsigned long long run_delay; /* time spent waiting on a runqueue */
768 
769 	/* timestamps */
770 	unsigned long long last_arrival,/* when we last ran on a cpu */
771 			   last_queued;	/* when we were last queued to run */
772 #ifdef CONFIG_SCHEDSTATS
773 	/* BKL stats */
774 	unsigned int bkl_count;
775 #endif
776 };
777 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
778 
779 #ifdef CONFIG_TASK_DELAY_ACCT
780 struct task_delay_info {
781 	spinlock_t	lock;
782 	unsigned int	flags;	/* Private per-task flags */
783 
784 	/* For each stat XXX, add following, aligned appropriately
785 	 *
786 	 * struct timespec XXX_start, XXX_end;
787 	 * u64 XXX_delay;
788 	 * u32 XXX_count;
789 	 *
790 	 * Atomicity of updates to XXX_delay, XXX_count protected by
791 	 * single lock above (split into XXX_lock if contention is an issue).
792 	 */
793 
794 	/*
795 	 * XXX_count is incremented on every XXX operation, the delay
796 	 * associated with the operation is added to XXX_delay.
797 	 * XXX_delay contains the accumulated delay time in nanoseconds.
798 	 */
799 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
800 	u64 blkio_delay;	/* wait for sync block io completion */
801 	u64 swapin_delay;	/* wait for swapin block io completion */
802 	u32 blkio_count;	/* total count of the number of sync block */
803 				/* io operations performed */
804 	u32 swapin_count;	/* total count of the number of swapin block */
805 				/* io operations performed */
806 
807 	struct timespec freepages_start, freepages_end;
808 	u64 freepages_delay;	/* wait for memory reclaim */
809 	u32 freepages_count;	/* total count of memory reclaim */
810 };
811 #endif	/* CONFIG_TASK_DELAY_ACCT */
812 
813 static inline int sched_info_on(void)
814 {
815 #ifdef CONFIG_SCHEDSTATS
816 	return 1;
817 #elif defined(CONFIG_TASK_DELAY_ACCT)
818 	extern int delayacct_on;
819 	return delayacct_on;
820 #else
821 	return 0;
822 #endif
823 }
824 
825 enum cpu_idle_type {
826 	CPU_IDLE,
827 	CPU_NOT_IDLE,
828 	CPU_NEWLY_IDLE,
829 	CPU_MAX_IDLE_TYPES
830 };
831 
832 /*
833  * sched-domains (multiprocessor balancing) declarations:
834  */
835 
836 /*
837  * Increase resolution of nice-level calculations:
838  */
839 #define SCHED_LOAD_SHIFT	10
840 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
841 
842 #define SCHED_LOAD_SCALE_FUZZ	SCHED_LOAD_SCALE
843 
844 #ifdef CONFIG_SMP
845 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
846 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
847 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
848 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
849 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
850 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
851 #define SD_PREFER_LOCAL		0x0040  /* Prefer to keep tasks local to this domain */
852 #define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
853 #define SD_POWERSAVINGS_BALANCE	0x0100	/* Balance for power savings */
854 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
855 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
856 
857 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
858 
859 enum powersavings_balance_level {
860 	POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
861 	POWERSAVINGS_BALANCE_BASIC,	/* Fill one thread/core/package
862 					 * first for long running threads
863 					 */
864 	POWERSAVINGS_BALANCE_WAKEUP,	/* Also bias task wakeups to semi-idle
865 					 * cpu package for power savings
866 					 */
867 	MAX_POWERSAVINGS_BALANCE_LEVELS
868 };
869 
870 extern int sched_mc_power_savings, sched_smt_power_savings;
871 
872 static inline int sd_balance_for_mc_power(void)
873 {
874 	if (sched_smt_power_savings)
875 		return SD_POWERSAVINGS_BALANCE;
876 
877 	return SD_PREFER_SIBLING;
878 }
879 
880 static inline int sd_balance_for_package_power(void)
881 {
882 	if (sched_mc_power_savings | sched_smt_power_savings)
883 		return SD_POWERSAVINGS_BALANCE;
884 
885 	return SD_PREFER_SIBLING;
886 }
887 
888 /*
889  * Optimise SD flags for power savings:
890  * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings.
891  * Keep default SD flags if sched_{smt,mc}_power_saving=0
892  */
893 
894 static inline int sd_power_saving_flags(void)
895 {
896 	if (sched_mc_power_savings | sched_smt_power_savings)
897 		return SD_BALANCE_NEWIDLE;
898 
899 	return 0;
900 }
901 
902 struct sched_group {
903 	struct sched_group *next;	/* Must be a circular list */
904 
905 	/*
906 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
907 	 * single CPU.
908 	 */
909 	unsigned int cpu_power;
910 
911 	/*
912 	 * The CPUs this group covers.
913 	 *
914 	 * NOTE: this field is variable length. (Allocated dynamically
915 	 * by attaching extra space to the end of the structure,
916 	 * depending on how many CPUs the kernel has booted up with)
917 	 *
918 	 * It is also be embedded into static data structures at build
919 	 * time. (See 'struct static_sched_group' in kernel/sched.c)
920 	 */
921 	unsigned long cpumask[0];
922 };
923 
924 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
925 {
926 	return to_cpumask(sg->cpumask);
927 }
928 
929 enum sched_domain_level {
930 	SD_LV_NONE = 0,
931 	SD_LV_SIBLING,
932 	SD_LV_MC,
933 	SD_LV_CPU,
934 	SD_LV_NODE,
935 	SD_LV_ALLNODES,
936 	SD_LV_MAX
937 };
938 
939 struct sched_domain_attr {
940 	int relax_domain_level;
941 };
942 
943 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
944 	.relax_domain_level = -1,			\
945 }
946 
947 struct sched_domain {
948 	/* These fields must be setup */
949 	struct sched_domain *parent;	/* top domain must be null terminated */
950 	struct sched_domain *child;	/* bottom domain must be null terminated */
951 	struct sched_group *groups;	/* the balancing groups of the domain */
952 	unsigned long min_interval;	/* Minimum balance interval ms */
953 	unsigned long max_interval;	/* Maximum balance interval ms */
954 	unsigned int busy_factor;	/* less balancing by factor if busy */
955 	unsigned int imbalance_pct;	/* No balance until over watermark */
956 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
957 	unsigned int busy_idx;
958 	unsigned int idle_idx;
959 	unsigned int newidle_idx;
960 	unsigned int wake_idx;
961 	unsigned int forkexec_idx;
962 	unsigned int smt_gain;
963 	int flags;			/* See SD_* */
964 	enum sched_domain_level level;
965 
966 	/* Runtime fields. */
967 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
968 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
969 	unsigned int nr_balance_failed; /* initialise to 0 */
970 
971 	u64 last_update;
972 
973 #ifdef CONFIG_SCHEDSTATS
974 	/* load_balance() stats */
975 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
976 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
977 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
978 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
979 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
980 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
981 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
982 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
983 
984 	/* Active load balancing */
985 	unsigned int alb_count;
986 	unsigned int alb_failed;
987 	unsigned int alb_pushed;
988 
989 	/* SD_BALANCE_EXEC stats */
990 	unsigned int sbe_count;
991 	unsigned int sbe_balanced;
992 	unsigned int sbe_pushed;
993 
994 	/* SD_BALANCE_FORK stats */
995 	unsigned int sbf_count;
996 	unsigned int sbf_balanced;
997 	unsigned int sbf_pushed;
998 
999 	/* try_to_wake_up() stats */
1000 	unsigned int ttwu_wake_remote;
1001 	unsigned int ttwu_move_affine;
1002 	unsigned int ttwu_move_balance;
1003 #endif
1004 #ifdef CONFIG_SCHED_DEBUG
1005 	char *name;
1006 #endif
1007 
1008 	/*
1009 	 * Span of all CPUs in this domain.
1010 	 *
1011 	 * NOTE: this field is variable length. (Allocated dynamically
1012 	 * by attaching extra space to the end of the structure,
1013 	 * depending on how many CPUs the kernel has booted up with)
1014 	 *
1015 	 * It is also be embedded into static data structures at build
1016 	 * time. (See 'struct static_sched_domain' in kernel/sched.c)
1017 	 */
1018 	unsigned long span[0];
1019 };
1020 
1021 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1022 {
1023 	return to_cpumask(sd->span);
1024 }
1025 
1026 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1027 				    struct sched_domain_attr *dattr_new);
1028 
1029 /* Allocate an array of sched domains, for partition_sched_domains(). */
1030 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1031 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1032 
1033 /* Test a flag in parent sched domain */
1034 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1035 {
1036 	if (sd->parent && (sd->parent->flags & flag))
1037 		return 1;
1038 
1039 	return 0;
1040 }
1041 
1042 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1043 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1044 
1045 #else /* CONFIG_SMP */
1046 
1047 struct sched_domain_attr;
1048 
1049 static inline void
1050 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1051 			struct sched_domain_attr *dattr_new)
1052 {
1053 }
1054 #endif	/* !CONFIG_SMP */
1055 
1056 
1057 struct io_context;			/* See blkdev.h */
1058 
1059 
1060 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1061 extern void prefetch_stack(struct task_struct *t);
1062 #else
1063 static inline void prefetch_stack(struct task_struct *t) { }
1064 #endif
1065 
1066 struct audit_context;		/* See audit.c */
1067 struct mempolicy;
1068 struct pipe_inode_info;
1069 struct uts_namespace;
1070 
1071 struct rq;
1072 struct sched_domain;
1073 
1074 /*
1075  * wake flags
1076  */
1077 #define WF_SYNC		0x01		/* waker goes to sleep after wakup */
1078 #define WF_FORK		0x02		/* child wakeup after fork */
1079 
1080 struct sched_class {
1081 	const struct sched_class *next;
1082 
1083 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
1084 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
1085 	void (*yield_task) (struct rq *rq);
1086 
1087 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1088 
1089 	struct task_struct * (*pick_next_task) (struct rq *rq);
1090 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1091 
1092 #ifdef CONFIG_SMP
1093 	int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1094 
1095 	unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
1096 			struct rq *busiest, unsigned long max_load_move,
1097 			struct sched_domain *sd, enum cpu_idle_type idle,
1098 			int *all_pinned, int *this_best_prio);
1099 
1100 	int (*move_one_task) (struct rq *this_rq, int this_cpu,
1101 			      struct rq *busiest, struct sched_domain *sd,
1102 			      enum cpu_idle_type idle);
1103 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1104 	void (*post_schedule) (struct rq *this_rq);
1105 	void (*task_waking) (struct rq *this_rq, struct task_struct *task);
1106 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1107 
1108 	void (*set_cpus_allowed)(struct task_struct *p,
1109 				 const struct cpumask *newmask);
1110 
1111 	void (*rq_online)(struct rq *rq);
1112 	void (*rq_offline)(struct rq *rq);
1113 #endif
1114 
1115 	void (*set_curr_task) (struct rq *rq);
1116 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1117 	void (*task_fork) (struct task_struct *p);
1118 
1119 	void (*switched_from) (struct rq *this_rq, struct task_struct *task,
1120 			       int running);
1121 	void (*switched_to) (struct rq *this_rq, struct task_struct *task,
1122 			     int running);
1123 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1124 			     int oldprio, int running);
1125 
1126 	unsigned int (*get_rr_interval) (struct rq *rq,
1127 					 struct task_struct *task);
1128 
1129 #ifdef CONFIG_FAIR_GROUP_SCHED
1130 	void (*moved_group) (struct task_struct *p, int on_rq);
1131 #endif
1132 };
1133 
1134 struct load_weight {
1135 	unsigned long weight, inv_weight;
1136 };
1137 
1138 /*
1139  * CFS stats for a schedulable entity (task, task-group etc)
1140  *
1141  * Current field usage histogram:
1142  *
1143  *     4 se->block_start
1144  *     4 se->run_node
1145  *     4 se->sleep_start
1146  *     6 se->load.weight
1147  */
1148 struct sched_entity {
1149 	struct load_weight	load;		/* for load-balancing */
1150 	struct rb_node		run_node;
1151 	struct list_head	group_node;
1152 	unsigned int		on_rq;
1153 
1154 	u64			exec_start;
1155 	u64			sum_exec_runtime;
1156 	u64			vruntime;
1157 	u64			prev_sum_exec_runtime;
1158 
1159 	u64			last_wakeup;
1160 	u64			avg_overlap;
1161 
1162 	u64			nr_migrations;
1163 
1164 	u64			start_runtime;
1165 	u64			avg_wakeup;
1166 
1167 #ifdef CONFIG_SCHEDSTATS
1168 	u64			wait_start;
1169 	u64			wait_max;
1170 	u64			wait_count;
1171 	u64			wait_sum;
1172 	u64			iowait_count;
1173 	u64			iowait_sum;
1174 
1175 	u64			sleep_start;
1176 	u64			sleep_max;
1177 	s64			sum_sleep_runtime;
1178 
1179 	u64			block_start;
1180 	u64			block_max;
1181 	u64			exec_max;
1182 	u64			slice_max;
1183 
1184 	u64			nr_migrations_cold;
1185 	u64			nr_failed_migrations_affine;
1186 	u64			nr_failed_migrations_running;
1187 	u64			nr_failed_migrations_hot;
1188 	u64			nr_forced_migrations;
1189 
1190 	u64			nr_wakeups;
1191 	u64			nr_wakeups_sync;
1192 	u64			nr_wakeups_migrate;
1193 	u64			nr_wakeups_local;
1194 	u64			nr_wakeups_remote;
1195 	u64			nr_wakeups_affine;
1196 	u64			nr_wakeups_affine_attempts;
1197 	u64			nr_wakeups_passive;
1198 	u64			nr_wakeups_idle;
1199 #endif
1200 
1201 #ifdef CONFIG_FAIR_GROUP_SCHED
1202 	struct sched_entity	*parent;
1203 	/* rq on which this entity is (to be) queued: */
1204 	struct cfs_rq		*cfs_rq;
1205 	/* rq "owned" by this entity/group: */
1206 	struct cfs_rq		*my_q;
1207 #endif
1208 };
1209 
1210 struct sched_rt_entity {
1211 	struct list_head run_list;
1212 	unsigned long timeout;
1213 	unsigned int time_slice;
1214 	int nr_cpus_allowed;
1215 
1216 	struct sched_rt_entity *back;
1217 #ifdef CONFIG_RT_GROUP_SCHED
1218 	struct sched_rt_entity	*parent;
1219 	/* rq on which this entity is (to be) queued: */
1220 	struct rt_rq		*rt_rq;
1221 	/* rq "owned" by this entity/group: */
1222 	struct rt_rq		*my_q;
1223 #endif
1224 };
1225 
1226 struct rcu_node;
1227 
1228 struct task_struct {
1229 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1230 	void *stack;
1231 	atomic_t usage;
1232 	unsigned int flags;	/* per process flags, defined below */
1233 	unsigned int ptrace;
1234 
1235 	int lock_depth;		/* BKL lock depth */
1236 
1237 #ifdef CONFIG_SMP
1238 #ifdef __ARCH_WANT_UNLOCKED_CTXSW
1239 	int oncpu;
1240 #endif
1241 #endif
1242 
1243 	int prio, static_prio, normal_prio;
1244 	unsigned int rt_priority;
1245 	const struct sched_class *sched_class;
1246 	struct sched_entity se;
1247 	struct sched_rt_entity rt;
1248 
1249 #ifdef CONFIG_PREEMPT_NOTIFIERS
1250 	/* list of struct preempt_notifier: */
1251 	struct hlist_head preempt_notifiers;
1252 #endif
1253 
1254 	/*
1255 	 * fpu_counter contains the number of consecutive context switches
1256 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1257 	 * saving becomes unlazy to save the trap. This is an unsigned char
1258 	 * so that after 256 times the counter wraps and the behavior turns
1259 	 * lazy again; this to deal with bursty apps that only use FPU for
1260 	 * a short time
1261 	 */
1262 	unsigned char fpu_counter;
1263 #ifdef CONFIG_BLK_DEV_IO_TRACE
1264 	unsigned int btrace_seq;
1265 #endif
1266 
1267 	unsigned int policy;
1268 	cpumask_t cpus_allowed;
1269 
1270 #ifdef CONFIG_TREE_PREEMPT_RCU
1271 	int rcu_read_lock_nesting;
1272 	char rcu_read_unlock_special;
1273 	struct rcu_node *rcu_blocked_node;
1274 	struct list_head rcu_node_entry;
1275 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1276 
1277 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1278 	struct sched_info sched_info;
1279 #endif
1280 
1281 	struct list_head tasks;
1282 	struct plist_node pushable_tasks;
1283 
1284 	struct mm_struct *mm, *active_mm;
1285 
1286 /* task state */
1287 	int exit_state;
1288 	int exit_code, exit_signal;
1289 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1290 	/* ??? */
1291 	unsigned int personality;
1292 	unsigned did_exec:1;
1293 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1294 				 * execve */
1295 	unsigned in_iowait:1;
1296 
1297 
1298 	/* Revert to default priority/policy when forking */
1299 	unsigned sched_reset_on_fork:1;
1300 
1301 	pid_t pid;
1302 	pid_t tgid;
1303 
1304 #ifdef CONFIG_CC_STACKPROTECTOR
1305 	/* Canary value for the -fstack-protector gcc feature */
1306 	unsigned long stack_canary;
1307 #endif
1308 
1309 	/*
1310 	 * pointers to (original) parent process, youngest child, younger sibling,
1311 	 * older sibling, respectively.  (p->father can be replaced with
1312 	 * p->real_parent->pid)
1313 	 */
1314 	struct task_struct *real_parent; /* real parent process */
1315 	struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1316 	/*
1317 	 * children/sibling forms the list of my natural children
1318 	 */
1319 	struct list_head children;	/* list of my children */
1320 	struct list_head sibling;	/* linkage in my parent's children list */
1321 	struct task_struct *group_leader;	/* threadgroup leader */
1322 
1323 	/*
1324 	 * ptraced is the list of tasks this task is using ptrace on.
1325 	 * This includes both natural children and PTRACE_ATTACH targets.
1326 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1327 	 */
1328 	struct list_head ptraced;
1329 	struct list_head ptrace_entry;
1330 
1331 	/*
1332 	 * This is the tracer handle for the ptrace BTS extension.
1333 	 * This field actually belongs to the ptracer task.
1334 	 */
1335 	struct bts_context *bts;
1336 
1337 	/* PID/PID hash table linkage. */
1338 	struct pid_link pids[PIDTYPE_MAX];
1339 	struct list_head thread_group;
1340 
1341 	struct completion *vfork_done;		/* for vfork() */
1342 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1343 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1344 
1345 	cputime_t utime, stime, utimescaled, stimescaled;
1346 	cputime_t gtime;
1347 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1348 	cputime_t prev_utime, prev_stime;
1349 #endif
1350 	unsigned long nvcsw, nivcsw; /* context switch counts */
1351 	struct timespec start_time; 		/* monotonic time */
1352 	struct timespec real_start_time;	/* boot based time */
1353 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1354 	unsigned long min_flt, maj_flt;
1355 
1356 	struct task_cputime cputime_expires;
1357 	struct list_head cpu_timers[3];
1358 
1359 /* process credentials */
1360 	const struct cred *real_cred;	/* objective and real subjective task
1361 					 * credentials (COW) */
1362 	const struct cred *cred;	/* effective (overridable) subjective task
1363 					 * credentials (COW) */
1364 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
1365 					 * credential calculations
1366 					 * (notably. ptrace) */
1367 	struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
1368 
1369 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1370 				     - access with [gs]et_task_comm (which lock
1371 				       it with task_lock())
1372 				     - initialized normally by flush_old_exec */
1373 /* file system info */
1374 	int link_count, total_link_count;
1375 #ifdef CONFIG_SYSVIPC
1376 /* ipc stuff */
1377 	struct sysv_sem sysvsem;
1378 #endif
1379 #ifdef CONFIG_DETECT_HUNG_TASK
1380 /* hung task detection */
1381 	unsigned long last_switch_count;
1382 #endif
1383 /* CPU-specific state of this task */
1384 	struct thread_struct thread;
1385 /* filesystem information */
1386 	struct fs_struct *fs;
1387 /* open file information */
1388 	struct files_struct *files;
1389 /* namespaces */
1390 	struct nsproxy *nsproxy;
1391 /* signal handlers */
1392 	struct signal_struct *signal;
1393 	struct sighand_struct *sighand;
1394 
1395 	sigset_t blocked, real_blocked;
1396 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1397 	struct sigpending pending;
1398 
1399 	unsigned long sas_ss_sp;
1400 	size_t sas_ss_size;
1401 	int (*notifier)(void *priv);
1402 	void *notifier_data;
1403 	sigset_t *notifier_mask;
1404 	struct audit_context *audit_context;
1405 #ifdef CONFIG_AUDITSYSCALL
1406 	uid_t loginuid;
1407 	unsigned int sessionid;
1408 #endif
1409 	seccomp_t seccomp;
1410 
1411 /* Thread group tracking */
1412    	u32 parent_exec_id;
1413    	u32 self_exec_id;
1414 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1415  * mempolicy */
1416 	spinlock_t alloc_lock;
1417 
1418 #ifdef CONFIG_GENERIC_HARDIRQS
1419 	/* IRQ handler threads */
1420 	struct irqaction *irqaction;
1421 #endif
1422 
1423 	/* Protection of the PI data structures: */
1424 	raw_spinlock_t pi_lock;
1425 
1426 #ifdef CONFIG_RT_MUTEXES
1427 	/* PI waiters blocked on a rt_mutex held by this task */
1428 	struct plist_head pi_waiters;
1429 	/* Deadlock detection and priority inheritance handling */
1430 	struct rt_mutex_waiter *pi_blocked_on;
1431 #endif
1432 
1433 #ifdef CONFIG_DEBUG_MUTEXES
1434 	/* mutex deadlock detection */
1435 	struct mutex_waiter *blocked_on;
1436 #endif
1437 #ifdef CONFIG_TRACE_IRQFLAGS
1438 	unsigned int irq_events;
1439 	unsigned long hardirq_enable_ip;
1440 	unsigned long hardirq_disable_ip;
1441 	unsigned int hardirq_enable_event;
1442 	unsigned int hardirq_disable_event;
1443 	int hardirqs_enabled;
1444 	int hardirq_context;
1445 	unsigned long softirq_disable_ip;
1446 	unsigned long softirq_enable_ip;
1447 	unsigned int softirq_disable_event;
1448 	unsigned int softirq_enable_event;
1449 	int softirqs_enabled;
1450 	int softirq_context;
1451 #endif
1452 #ifdef CONFIG_LOCKDEP
1453 # define MAX_LOCK_DEPTH 48UL
1454 	u64 curr_chain_key;
1455 	int lockdep_depth;
1456 	unsigned int lockdep_recursion;
1457 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1458 	gfp_t lockdep_reclaim_gfp;
1459 #endif
1460 
1461 /* journalling filesystem info */
1462 	void *journal_info;
1463 
1464 /* stacked block device info */
1465 	struct bio *bio_list, **bio_tail;
1466 
1467 /* VM state */
1468 	struct reclaim_state *reclaim_state;
1469 
1470 	struct backing_dev_info *backing_dev_info;
1471 
1472 	struct io_context *io_context;
1473 
1474 	unsigned long ptrace_message;
1475 	siginfo_t *last_siginfo; /* For ptrace use.  */
1476 	struct task_io_accounting ioac;
1477 #if defined(CONFIG_TASK_XACCT)
1478 	u64 acct_rss_mem1;	/* accumulated rss usage */
1479 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1480 	cputime_t acct_timexpd;	/* stime + utime since last update */
1481 #endif
1482 #ifdef CONFIG_CPUSETS
1483 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1484 	int cpuset_mem_spread_rotor;
1485 #endif
1486 #ifdef CONFIG_CGROUPS
1487 	/* Control Group info protected by css_set_lock */
1488 	struct css_set *cgroups;
1489 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1490 	struct list_head cg_list;
1491 #endif
1492 #ifdef CONFIG_FUTEX
1493 	struct robust_list_head __user *robust_list;
1494 #ifdef CONFIG_COMPAT
1495 	struct compat_robust_list_head __user *compat_robust_list;
1496 #endif
1497 	struct list_head pi_state_list;
1498 	struct futex_pi_state *pi_state_cache;
1499 #endif
1500 #ifdef CONFIG_PERF_EVENTS
1501 	struct perf_event_context *perf_event_ctxp;
1502 	struct mutex perf_event_mutex;
1503 	struct list_head perf_event_list;
1504 #endif
1505 #ifdef CONFIG_NUMA
1506 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1507 	short il_next;
1508 #endif
1509 	atomic_t fs_excl;	/* holding fs exclusive resources */
1510 	struct rcu_head rcu;
1511 
1512 	/*
1513 	 * cache last used pipe for splice
1514 	 */
1515 	struct pipe_inode_info *splice_pipe;
1516 #ifdef	CONFIG_TASK_DELAY_ACCT
1517 	struct task_delay_info *delays;
1518 #endif
1519 #ifdef CONFIG_FAULT_INJECTION
1520 	int make_it_fail;
1521 #endif
1522 	struct prop_local_single dirties;
1523 #ifdef CONFIG_LATENCYTOP
1524 	int latency_record_count;
1525 	struct latency_record latency_record[LT_SAVECOUNT];
1526 #endif
1527 	/*
1528 	 * time slack values; these are used to round up poll() and
1529 	 * select() etc timeout values. These are in nanoseconds.
1530 	 */
1531 	unsigned long timer_slack_ns;
1532 	unsigned long default_timer_slack_ns;
1533 
1534 	struct list_head	*scm_work_list;
1535 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1536 	/* Index of current stored adress in ret_stack */
1537 	int curr_ret_stack;
1538 	/* Stack of return addresses for return function tracing */
1539 	struct ftrace_ret_stack	*ret_stack;
1540 	/* time stamp for last schedule */
1541 	unsigned long long ftrace_timestamp;
1542 	/*
1543 	 * Number of functions that haven't been traced
1544 	 * because of depth overrun.
1545 	 */
1546 	atomic_t trace_overrun;
1547 	/* Pause for the tracing */
1548 	atomic_t tracing_graph_pause;
1549 #endif
1550 #ifdef CONFIG_TRACING
1551 	/* state flags for use by tracers */
1552 	unsigned long trace;
1553 	/* bitmask of trace recursion */
1554 	unsigned long trace_recursion;
1555 #endif /* CONFIG_TRACING */
1556 	unsigned long stack_start;
1557 #ifdef CONFIG_CGROUP_MEM_RES_CTLR /* memcg uses this to do batch job */
1558 	struct memcg_batch_info {
1559 		int do_batch;	/* incremented when batch uncharge started */
1560 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1561 		unsigned long bytes; 		/* uncharged usage */
1562 		unsigned long memsw_bytes; /* uncharged mem+swap usage */
1563 	} memcg_batch;
1564 #endif
1565 };
1566 
1567 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1568 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1569 
1570 /*
1571  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1572  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1573  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1574  * values are inverted: lower p->prio value means higher priority.
1575  *
1576  * The MAX_USER_RT_PRIO value allows the actual maximum
1577  * RT priority to be separate from the value exported to
1578  * user-space.  This allows kernel threads to set their
1579  * priority to a value higher than any user task. Note:
1580  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1581  */
1582 
1583 #define MAX_USER_RT_PRIO	100
1584 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1585 
1586 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1587 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1588 
1589 static inline int rt_prio(int prio)
1590 {
1591 	if (unlikely(prio < MAX_RT_PRIO))
1592 		return 1;
1593 	return 0;
1594 }
1595 
1596 static inline int rt_task(struct task_struct *p)
1597 {
1598 	return rt_prio(p->prio);
1599 }
1600 
1601 static inline struct pid *task_pid(struct task_struct *task)
1602 {
1603 	return task->pids[PIDTYPE_PID].pid;
1604 }
1605 
1606 static inline struct pid *task_tgid(struct task_struct *task)
1607 {
1608 	return task->group_leader->pids[PIDTYPE_PID].pid;
1609 }
1610 
1611 /*
1612  * Without tasklist or rcu lock it is not safe to dereference
1613  * the result of task_pgrp/task_session even if task == current,
1614  * we can race with another thread doing sys_setsid/sys_setpgid.
1615  */
1616 static inline struct pid *task_pgrp(struct task_struct *task)
1617 {
1618 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1619 }
1620 
1621 static inline struct pid *task_session(struct task_struct *task)
1622 {
1623 	return task->group_leader->pids[PIDTYPE_SID].pid;
1624 }
1625 
1626 struct pid_namespace;
1627 
1628 /*
1629  * the helpers to get the task's different pids as they are seen
1630  * from various namespaces
1631  *
1632  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1633  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1634  *                     current.
1635  * task_xid_nr_ns()  : id seen from the ns specified;
1636  *
1637  * set_task_vxid()   : assigns a virtual id to a task;
1638  *
1639  * see also pid_nr() etc in include/linux/pid.h
1640  */
1641 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1642 			struct pid_namespace *ns);
1643 
1644 static inline pid_t task_pid_nr(struct task_struct *tsk)
1645 {
1646 	return tsk->pid;
1647 }
1648 
1649 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1650 					struct pid_namespace *ns)
1651 {
1652 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1653 }
1654 
1655 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1656 {
1657 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1658 }
1659 
1660 
1661 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1662 {
1663 	return tsk->tgid;
1664 }
1665 
1666 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1667 
1668 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1669 {
1670 	return pid_vnr(task_tgid(tsk));
1671 }
1672 
1673 
1674 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1675 					struct pid_namespace *ns)
1676 {
1677 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1678 }
1679 
1680 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1681 {
1682 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1683 }
1684 
1685 
1686 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1687 					struct pid_namespace *ns)
1688 {
1689 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1690 }
1691 
1692 static inline pid_t task_session_vnr(struct task_struct *tsk)
1693 {
1694 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1695 }
1696 
1697 /* obsolete, do not use */
1698 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1699 {
1700 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1701 }
1702 
1703 /**
1704  * pid_alive - check that a task structure is not stale
1705  * @p: Task structure to be checked.
1706  *
1707  * Test if a process is not yet dead (at most zombie state)
1708  * If pid_alive fails, then pointers within the task structure
1709  * can be stale and must not be dereferenced.
1710  */
1711 static inline int pid_alive(struct task_struct *p)
1712 {
1713 	return p->pids[PIDTYPE_PID].pid != NULL;
1714 }
1715 
1716 /**
1717  * is_global_init - check if a task structure is init
1718  * @tsk: Task structure to be checked.
1719  *
1720  * Check if a task structure is the first user space task the kernel created.
1721  */
1722 static inline int is_global_init(struct task_struct *tsk)
1723 {
1724 	return tsk->pid == 1;
1725 }
1726 
1727 /*
1728  * is_container_init:
1729  * check whether in the task is init in its own pid namespace.
1730  */
1731 extern int is_container_init(struct task_struct *tsk);
1732 
1733 extern struct pid *cad_pid;
1734 
1735 extern void free_task(struct task_struct *tsk);
1736 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1737 
1738 extern void __put_task_struct(struct task_struct *t);
1739 
1740 static inline void put_task_struct(struct task_struct *t)
1741 {
1742 	if (atomic_dec_and_test(&t->usage))
1743 		__put_task_struct(t);
1744 }
1745 
1746 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1747 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1748 
1749 /*
1750  * Per process flags
1751  */
1752 #define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
1753 					/* Not implemented yet, only for 486*/
1754 #define PF_STARTING	0x00000002	/* being created */
1755 #define PF_EXITING	0x00000004	/* getting shut down */
1756 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1757 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1758 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1759 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1760 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1761 #define PF_DUMPCORE	0x00000200	/* dumped core */
1762 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1763 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1764 #define PF_FLUSHER	0x00001000	/* responsible for disk writeback */
1765 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1766 #define PF_FREEZING	0x00004000	/* freeze in progress. do not account to load */
1767 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1768 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1769 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1770 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1771 #define PF_OOM_ORIGIN	0x00080000	/* Allocating much memory to others */
1772 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1773 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1774 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1775 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1776 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1777 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1778 #define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1779 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1780 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1781 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1782 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezeable */
1783 #define PF_FREEZER_NOSIG 0x80000000	/* Freezer won't send signals to it */
1784 
1785 /*
1786  * Only the _current_ task can read/write to tsk->flags, but other
1787  * tasks can access tsk->flags in readonly mode for example
1788  * with tsk_used_math (like during threaded core dumping).
1789  * There is however an exception to this rule during ptrace
1790  * or during fork: the ptracer task is allowed to write to the
1791  * child->flags of its traced child (same goes for fork, the parent
1792  * can write to the child->flags), because we're guaranteed the
1793  * child is not running and in turn not changing child->flags
1794  * at the same time the parent does it.
1795  */
1796 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1797 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1798 #define clear_used_math() clear_stopped_child_used_math(current)
1799 #define set_used_math() set_stopped_child_used_math(current)
1800 #define conditional_stopped_child_used_math(condition, child) \
1801 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1802 #define conditional_used_math(condition) \
1803 	conditional_stopped_child_used_math(condition, current)
1804 #define copy_to_stopped_child_used_math(child) \
1805 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1806 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1807 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1808 #define used_math() tsk_used_math(current)
1809 
1810 #ifdef CONFIG_TREE_PREEMPT_RCU
1811 
1812 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1813 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1814 
1815 static inline void rcu_copy_process(struct task_struct *p)
1816 {
1817 	p->rcu_read_lock_nesting = 0;
1818 	p->rcu_read_unlock_special = 0;
1819 	p->rcu_blocked_node = NULL;
1820 	INIT_LIST_HEAD(&p->rcu_node_entry);
1821 }
1822 
1823 #else
1824 
1825 static inline void rcu_copy_process(struct task_struct *p)
1826 {
1827 }
1828 
1829 #endif
1830 
1831 #ifdef CONFIG_SMP
1832 extern int set_cpus_allowed_ptr(struct task_struct *p,
1833 				const struct cpumask *new_mask);
1834 #else
1835 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1836 				       const struct cpumask *new_mask)
1837 {
1838 	if (!cpumask_test_cpu(0, new_mask))
1839 		return -EINVAL;
1840 	return 0;
1841 }
1842 #endif
1843 
1844 #ifndef CONFIG_CPUMASK_OFFSTACK
1845 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1846 {
1847 	return set_cpus_allowed_ptr(p, &new_mask);
1848 }
1849 #endif
1850 
1851 /*
1852  * Architectures can set this to 1 if they have specified
1853  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1854  * but then during bootup it turns out that sched_clock()
1855  * is reliable after all:
1856  */
1857 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1858 extern int sched_clock_stable;
1859 #endif
1860 
1861 /* ftrace calls sched_clock() directly */
1862 extern unsigned long long notrace sched_clock(void);
1863 
1864 extern void sched_clock_init(void);
1865 extern u64 sched_clock_cpu(int cpu);
1866 
1867 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1868 static inline void sched_clock_tick(void)
1869 {
1870 }
1871 
1872 static inline void sched_clock_idle_sleep_event(void)
1873 {
1874 }
1875 
1876 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1877 {
1878 }
1879 #else
1880 extern void sched_clock_tick(void);
1881 extern void sched_clock_idle_sleep_event(void);
1882 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1883 #endif
1884 
1885 /*
1886  * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
1887  * clock constructed from sched_clock():
1888  */
1889 extern unsigned long long cpu_clock(int cpu);
1890 
1891 extern unsigned long long
1892 task_sched_runtime(struct task_struct *task);
1893 extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
1894 
1895 /* sched_exec is called by processes performing an exec */
1896 #ifdef CONFIG_SMP
1897 extern void sched_exec(void);
1898 #else
1899 #define sched_exec()   {}
1900 #endif
1901 
1902 extern void sched_clock_idle_sleep_event(void);
1903 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1904 
1905 #ifdef CONFIG_HOTPLUG_CPU
1906 extern void idle_task_exit(void);
1907 #else
1908 static inline void idle_task_exit(void) {}
1909 #endif
1910 
1911 extern void sched_idle_next(void);
1912 
1913 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1914 extern void wake_up_idle_cpu(int cpu);
1915 #else
1916 static inline void wake_up_idle_cpu(int cpu) { }
1917 #endif
1918 
1919 extern unsigned int sysctl_sched_latency;
1920 extern unsigned int sysctl_sched_min_granularity;
1921 extern unsigned int sysctl_sched_wakeup_granularity;
1922 extern unsigned int sysctl_sched_shares_ratelimit;
1923 extern unsigned int sysctl_sched_shares_thresh;
1924 extern unsigned int sysctl_sched_child_runs_first;
1925 
1926 enum sched_tunable_scaling {
1927 	SCHED_TUNABLESCALING_NONE,
1928 	SCHED_TUNABLESCALING_LOG,
1929 	SCHED_TUNABLESCALING_LINEAR,
1930 	SCHED_TUNABLESCALING_END,
1931 };
1932 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
1933 
1934 #ifdef CONFIG_SCHED_DEBUG
1935 extern unsigned int sysctl_sched_migration_cost;
1936 extern unsigned int sysctl_sched_nr_migrate;
1937 extern unsigned int sysctl_sched_time_avg;
1938 extern unsigned int sysctl_timer_migration;
1939 
1940 int sched_proc_update_handler(struct ctl_table *table, int write,
1941 		void __user *buffer, size_t *length,
1942 		loff_t *ppos);
1943 #endif
1944 #ifdef CONFIG_SCHED_DEBUG
1945 static inline unsigned int get_sysctl_timer_migration(void)
1946 {
1947 	return sysctl_timer_migration;
1948 }
1949 #else
1950 static inline unsigned int get_sysctl_timer_migration(void)
1951 {
1952 	return 1;
1953 }
1954 #endif
1955 extern unsigned int sysctl_sched_rt_period;
1956 extern int sysctl_sched_rt_runtime;
1957 
1958 int sched_rt_handler(struct ctl_table *table, int write,
1959 		void __user *buffer, size_t *lenp,
1960 		loff_t *ppos);
1961 
1962 extern unsigned int sysctl_sched_compat_yield;
1963 
1964 #ifdef CONFIG_RT_MUTEXES
1965 extern int rt_mutex_getprio(struct task_struct *p);
1966 extern void rt_mutex_setprio(struct task_struct *p, int prio);
1967 extern void rt_mutex_adjust_pi(struct task_struct *p);
1968 #else
1969 static inline int rt_mutex_getprio(struct task_struct *p)
1970 {
1971 	return p->normal_prio;
1972 }
1973 # define rt_mutex_adjust_pi(p)		do { } while (0)
1974 #endif
1975 
1976 extern void set_user_nice(struct task_struct *p, long nice);
1977 extern int task_prio(const struct task_struct *p);
1978 extern int task_nice(const struct task_struct *p);
1979 extern int can_nice(const struct task_struct *p, const int nice);
1980 extern int task_curr(const struct task_struct *p);
1981 extern int idle_cpu(int cpu);
1982 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1983 extern int sched_setscheduler_nocheck(struct task_struct *, int,
1984 				      struct sched_param *);
1985 extern struct task_struct *idle_task(int cpu);
1986 extern struct task_struct *curr_task(int cpu);
1987 extern void set_curr_task(int cpu, struct task_struct *p);
1988 
1989 void yield(void);
1990 
1991 /*
1992  * The default (Linux) execution domain.
1993  */
1994 extern struct exec_domain	default_exec_domain;
1995 
1996 union thread_union {
1997 	struct thread_info thread_info;
1998 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1999 };
2000 
2001 #ifndef __HAVE_ARCH_KSTACK_END
2002 static inline int kstack_end(void *addr)
2003 {
2004 	/* Reliable end of stack detection:
2005 	 * Some APM bios versions misalign the stack
2006 	 */
2007 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2008 }
2009 #endif
2010 
2011 extern union thread_union init_thread_union;
2012 extern struct task_struct init_task;
2013 
2014 extern struct   mm_struct init_mm;
2015 
2016 extern struct pid_namespace init_pid_ns;
2017 
2018 /*
2019  * find a task by one of its numerical ids
2020  *
2021  * find_task_by_pid_ns():
2022  *      finds a task by its pid in the specified namespace
2023  * find_task_by_vpid():
2024  *      finds a task by its virtual pid
2025  *
2026  * see also find_vpid() etc in include/linux/pid.h
2027  */
2028 
2029 extern struct task_struct *find_task_by_vpid(pid_t nr);
2030 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2031 		struct pid_namespace *ns);
2032 
2033 extern void __set_special_pids(struct pid *pid);
2034 
2035 /* per-UID process charging. */
2036 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
2037 static inline struct user_struct *get_uid(struct user_struct *u)
2038 {
2039 	atomic_inc(&u->__count);
2040 	return u;
2041 }
2042 extern void free_uid(struct user_struct *);
2043 extern void release_uids(struct user_namespace *ns);
2044 
2045 #include <asm/current.h>
2046 
2047 extern void do_timer(unsigned long ticks);
2048 
2049 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2050 extern int wake_up_process(struct task_struct *tsk);
2051 extern void wake_up_new_task(struct task_struct *tsk,
2052 				unsigned long clone_flags);
2053 #ifdef CONFIG_SMP
2054  extern void kick_process(struct task_struct *tsk);
2055 #else
2056  static inline void kick_process(struct task_struct *tsk) { }
2057 #endif
2058 extern void sched_fork(struct task_struct *p, int clone_flags);
2059 extern void sched_dead(struct task_struct *p);
2060 
2061 extern void proc_caches_init(void);
2062 extern void flush_signals(struct task_struct *);
2063 extern void __flush_signals(struct task_struct *);
2064 extern void ignore_signals(struct task_struct *);
2065 extern void flush_signal_handlers(struct task_struct *, int force_default);
2066 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2067 
2068 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2069 {
2070 	unsigned long flags;
2071 	int ret;
2072 
2073 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2074 	ret = dequeue_signal(tsk, mask, info);
2075 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2076 
2077 	return ret;
2078 }
2079 
2080 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2081 			      sigset_t *mask);
2082 extern void unblock_all_signals(void);
2083 extern void release_task(struct task_struct * p);
2084 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2085 extern int force_sigsegv(int, struct task_struct *);
2086 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2087 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2088 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2089 extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
2090 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2091 extern int kill_pid(struct pid *pid, int sig, int priv);
2092 extern int kill_proc_info(int, struct siginfo *, pid_t);
2093 extern int do_notify_parent(struct task_struct *, int);
2094 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2095 extern void force_sig(int, struct task_struct *);
2096 extern int send_sig(int, struct task_struct *, int);
2097 extern void zap_other_threads(struct task_struct *p);
2098 extern struct sigqueue *sigqueue_alloc(void);
2099 extern void sigqueue_free(struct sigqueue *);
2100 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2101 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2102 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2103 
2104 static inline int kill_cad_pid(int sig, int priv)
2105 {
2106 	return kill_pid(cad_pid, sig, priv);
2107 }
2108 
2109 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2110 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2111 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2112 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2113 
2114 /*
2115  * True if we are on the alternate signal stack.
2116  */
2117 static inline int on_sig_stack(unsigned long sp)
2118 {
2119 #ifdef CONFIG_STACK_GROWSUP
2120 	return sp >= current->sas_ss_sp &&
2121 		sp - current->sas_ss_sp < current->sas_ss_size;
2122 #else
2123 	return sp > current->sas_ss_sp &&
2124 		sp - current->sas_ss_sp <= current->sas_ss_size;
2125 #endif
2126 }
2127 
2128 static inline int sas_ss_flags(unsigned long sp)
2129 {
2130 	return (current->sas_ss_size == 0 ? SS_DISABLE
2131 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2132 }
2133 
2134 /*
2135  * Routines for handling mm_structs
2136  */
2137 extern struct mm_struct * mm_alloc(void);
2138 
2139 /* mmdrop drops the mm and the page tables */
2140 extern void __mmdrop(struct mm_struct *);
2141 static inline void mmdrop(struct mm_struct * mm)
2142 {
2143 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2144 		__mmdrop(mm);
2145 }
2146 
2147 /* mmput gets rid of the mappings and all user-space */
2148 extern void mmput(struct mm_struct *);
2149 /* Grab a reference to a task's mm, if it is not already going away */
2150 extern struct mm_struct *get_task_mm(struct task_struct *task);
2151 /* Remove the current tasks stale references to the old mm_struct */
2152 extern void mm_release(struct task_struct *, struct mm_struct *);
2153 /* Allocate a new mm structure and copy contents from tsk->mm */
2154 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2155 
2156 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2157 			struct task_struct *, struct pt_regs *);
2158 extern void flush_thread(void);
2159 extern void exit_thread(void);
2160 
2161 extern void exit_files(struct task_struct *);
2162 extern void __cleanup_signal(struct signal_struct *);
2163 extern void __cleanup_sighand(struct sighand_struct *);
2164 
2165 extern void exit_itimers(struct signal_struct *);
2166 extern void flush_itimer_signals(void);
2167 
2168 extern NORET_TYPE void do_group_exit(int);
2169 
2170 extern void daemonize(const char *, ...);
2171 extern int allow_signal(int);
2172 extern int disallow_signal(int);
2173 
2174 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
2175 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2176 struct task_struct *fork_idle(int);
2177 
2178 extern void set_task_comm(struct task_struct *tsk, char *from);
2179 extern char *get_task_comm(char *to, struct task_struct *tsk);
2180 
2181 #ifdef CONFIG_SMP
2182 extern void wait_task_context_switch(struct task_struct *p);
2183 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2184 #else
2185 static inline void wait_task_context_switch(struct task_struct *p) {}
2186 static inline unsigned long wait_task_inactive(struct task_struct *p,
2187 					       long match_state)
2188 {
2189 	return 1;
2190 }
2191 #endif
2192 
2193 #define next_task(p) \
2194 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2195 
2196 #define for_each_process(p) \
2197 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2198 
2199 extern bool current_is_single_threaded(void);
2200 
2201 /*
2202  * Careful: do_each_thread/while_each_thread is a double loop so
2203  *          'break' will not work as expected - use goto instead.
2204  */
2205 #define do_each_thread(g, t) \
2206 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2207 
2208 #define while_each_thread(g, t) \
2209 	while ((t = next_thread(t)) != g)
2210 
2211 /* de_thread depends on thread_group_leader not being a pid based check */
2212 #define thread_group_leader(p)	(p == p->group_leader)
2213 
2214 /* Do to the insanities of de_thread it is possible for a process
2215  * to have the pid of the thread group leader without actually being
2216  * the thread group leader.  For iteration through the pids in proc
2217  * all we care about is that we have a task with the appropriate
2218  * pid, we don't actually care if we have the right task.
2219  */
2220 static inline int has_group_leader_pid(struct task_struct *p)
2221 {
2222 	return p->pid == p->tgid;
2223 }
2224 
2225 static inline
2226 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2227 {
2228 	return p1->tgid == p2->tgid;
2229 }
2230 
2231 static inline struct task_struct *next_thread(const struct task_struct *p)
2232 {
2233 	return list_entry_rcu(p->thread_group.next,
2234 			      struct task_struct, thread_group);
2235 }
2236 
2237 static inline int thread_group_empty(struct task_struct *p)
2238 {
2239 	return list_empty(&p->thread_group);
2240 }
2241 
2242 #define delay_group_leader(p) \
2243 		(thread_group_leader(p) && !thread_group_empty(p))
2244 
2245 static inline int task_detached(struct task_struct *p)
2246 {
2247 	return p->exit_signal == -1;
2248 }
2249 
2250 /*
2251  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2252  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2253  * pins the final release of task.io_context.  Also protects ->cpuset and
2254  * ->cgroup.subsys[].
2255  *
2256  * Nests both inside and outside of read_lock(&tasklist_lock).
2257  * It must not be nested with write_lock_irq(&tasklist_lock),
2258  * neither inside nor outside.
2259  */
2260 static inline void task_lock(struct task_struct *p)
2261 {
2262 	spin_lock(&p->alloc_lock);
2263 }
2264 
2265 static inline void task_unlock(struct task_struct *p)
2266 {
2267 	spin_unlock(&p->alloc_lock);
2268 }
2269 
2270 extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2271 							unsigned long *flags);
2272 
2273 static inline void unlock_task_sighand(struct task_struct *tsk,
2274 						unsigned long *flags)
2275 {
2276 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2277 }
2278 
2279 #ifndef __HAVE_THREAD_FUNCTIONS
2280 
2281 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2282 #define task_stack_page(task)	((task)->stack)
2283 
2284 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2285 {
2286 	*task_thread_info(p) = *task_thread_info(org);
2287 	task_thread_info(p)->task = p;
2288 }
2289 
2290 static inline unsigned long *end_of_stack(struct task_struct *p)
2291 {
2292 	return (unsigned long *)(task_thread_info(p) + 1);
2293 }
2294 
2295 #endif
2296 
2297 static inline int object_is_on_stack(void *obj)
2298 {
2299 	void *stack = task_stack_page(current);
2300 
2301 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2302 }
2303 
2304 extern void thread_info_cache_init(void);
2305 
2306 #ifdef CONFIG_DEBUG_STACK_USAGE
2307 static inline unsigned long stack_not_used(struct task_struct *p)
2308 {
2309 	unsigned long *n = end_of_stack(p);
2310 
2311 	do { 	/* Skip over canary */
2312 		n++;
2313 	} while (!*n);
2314 
2315 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2316 }
2317 #endif
2318 
2319 /* set thread flags in other task's structures
2320  * - see asm/thread_info.h for TIF_xxxx flags available
2321  */
2322 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2323 {
2324 	set_ti_thread_flag(task_thread_info(tsk), flag);
2325 }
2326 
2327 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2328 {
2329 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2330 }
2331 
2332 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2333 {
2334 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2335 }
2336 
2337 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2338 {
2339 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2340 }
2341 
2342 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2343 {
2344 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2345 }
2346 
2347 static inline void set_tsk_need_resched(struct task_struct *tsk)
2348 {
2349 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2350 }
2351 
2352 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2353 {
2354 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2355 }
2356 
2357 static inline int test_tsk_need_resched(struct task_struct *tsk)
2358 {
2359 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2360 }
2361 
2362 static inline int restart_syscall(void)
2363 {
2364 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2365 	return -ERESTARTNOINTR;
2366 }
2367 
2368 static inline int signal_pending(struct task_struct *p)
2369 {
2370 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2371 }
2372 
2373 static inline int __fatal_signal_pending(struct task_struct *p)
2374 {
2375 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2376 }
2377 
2378 static inline int fatal_signal_pending(struct task_struct *p)
2379 {
2380 	return signal_pending(p) && __fatal_signal_pending(p);
2381 }
2382 
2383 static inline int signal_pending_state(long state, struct task_struct *p)
2384 {
2385 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2386 		return 0;
2387 	if (!signal_pending(p))
2388 		return 0;
2389 
2390 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2391 }
2392 
2393 static inline int need_resched(void)
2394 {
2395 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2396 }
2397 
2398 /*
2399  * cond_resched() and cond_resched_lock(): latency reduction via
2400  * explicit rescheduling in places that are safe. The return
2401  * value indicates whether a reschedule was done in fact.
2402  * cond_resched_lock() will drop the spinlock before scheduling,
2403  * cond_resched_softirq() will enable bhs before scheduling.
2404  */
2405 extern int _cond_resched(void);
2406 
2407 #define cond_resched() ({			\
2408 	__might_sleep(__FILE__, __LINE__, 0);	\
2409 	_cond_resched();			\
2410 })
2411 
2412 extern int __cond_resched_lock(spinlock_t *lock);
2413 
2414 #ifdef CONFIG_PREEMPT
2415 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2416 #else
2417 #define PREEMPT_LOCK_OFFSET	0
2418 #endif
2419 
2420 #define cond_resched_lock(lock) ({				\
2421 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2422 	__cond_resched_lock(lock);				\
2423 })
2424 
2425 extern int __cond_resched_softirq(void);
2426 
2427 #define cond_resched_softirq() ({				\
2428 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_OFFSET);	\
2429 	__cond_resched_softirq();				\
2430 })
2431 
2432 /*
2433  * Does a critical section need to be broken due to another
2434  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2435  * but a general need for low latency)
2436  */
2437 static inline int spin_needbreak(spinlock_t *lock)
2438 {
2439 #ifdef CONFIG_PREEMPT
2440 	return spin_is_contended(lock);
2441 #else
2442 	return 0;
2443 #endif
2444 }
2445 
2446 /*
2447  * Thread group CPU time accounting.
2448  */
2449 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2450 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2451 
2452 static inline void thread_group_cputime_init(struct signal_struct *sig)
2453 {
2454 	sig->cputimer.cputime = INIT_CPUTIME;
2455 	spin_lock_init(&sig->cputimer.lock);
2456 	sig->cputimer.running = 0;
2457 }
2458 
2459 static inline void thread_group_cputime_free(struct signal_struct *sig)
2460 {
2461 }
2462 
2463 /*
2464  * Reevaluate whether the task has signals pending delivery.
2465  * Wake the task if so.
2466  * This is required every time the blocked sigset_t changes.
2467  * callers must hold sighand->siglock.
2468  */
2469 extern void recalc_sigpending_and_wake(struct task_struct *t);
2470 extern void recalc_sigpending(void);
2471 
2472 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2473 
2474 /*
2475  * Wrappers for p->thread_info->cpu access. No-op on UP.
2476  */
2477 #ifdef CONFIG_SMP
2478 
2479 static inline unsigned int task_cpu(const struct task_struct *p)
2480 {
2481 	return task_thread_info(p)->cpu;
2482 }
2483 
2484 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2485 
2486 #else
2487 
2488 static inline unsigned int task_cpu(const struct task_struct *p)
2489 {
2490 	return 0;
2491 }
2492 
2493 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2494 {
2495 }
2496 
2497 #endif /* CONFIG_SMP */
2498 
2499 #ifdef CONFIG_TRACING
2500 extern void
2501 __trace_special(void *__tr, void *__data,
2502 		unsigned long arg1, unsigned long arg2, unsigned long arg3);
2503 #else
2504 static inline void
2505 __trace_special(void *__tr, void *__data,
2506 		unsigned long arg1, unsigned long arg2, unsigned long arg3)
2507 {
2508 }
2509 #endif
2510 
2511 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2512 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2513 
2514 extern void normalize_rt_tasks(void);
2515 
2516 #ifdef CONFIG_GROUP_SCHED
2517 
2518 extern struct task_group init_task_group;
2519 #ifdef CONFIG_USER_SCHED
2520 extern struct task_group root_task_group;
2521 extern void set_tg_uid(struct user_struct *user);
2522 #endif
2523 
2524 extern struct task_group *sched_create_group(struct task_group *parent);
2525 extern void sched_destroy_group(struct task_group *tg);
2526 extern void sched_move_task(struct task_struct *tsk);
2527 #ifdef CONFIG_FAIR_GROUP_SCHED
2528 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2529 extern unsigned long sched_group_shares(struct task_group *tg);
2530 #endif
2531 #ifdef CONFIG_RT_GROUP_SCHED
2532 extern int sched_group_set_rt_runtime(struct task_group *tg,
2533 				      long rt_runtime_us);
2534 extern long sched_group_rt_runtime(struct task_group *tg);
2535 extern int sched_group_set_rt_period(struct task_group *tg,
2536 				      long rt_period_us);
2537 extern long sched_group_rt_period(struct task_group *tg);
2538 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2539 #endif
2540 #endif
2541 
2542 extern int task_can_switch_user(struct user_struct *up,
2543 					struct task_struct *tsk);
2544 
2545 #ifdef CONFIG_TASK_XACCT
2546 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2547 {
2548 	tsk->ioac.rchar += amt;
2549 }
2550 
2551 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2552 {
2553 	tsk->ioac.wchar += amt;
2554 }
2555 
2556 static inline void inc_syscr(struct task_struct *tsk)
2557 {
2558 	tsk->ioac.syscr++;
2559 }
2560 
2561 static inline void inc_syscw(struct task_struct *tsk)
2562 {
2563 	tsk->ioac.syscw++;
2564 }
2565 #else
2566 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2567 {
2568 }
2569 
2570 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2571 {
2572 }
2573 
2574 static inline void inc_syscr(struct task_struct *tsk)
2575 {
2576 }
2577 
2578 static inline void inc_syscw(struct task_struct *tsk)
2579 {
2580 }
2581 #endif
2582 
2583 #ifndef TASK_SIZE_OF
2584 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2585 #endif
2586 
2587 /*
2588  * Call the function if the target task is executing on a CPU right now:
2589  */
2590 extern void task_oncpu_function_call(struct task_struct *p,
2591 				     void (*func) (void *info), void *info);
2592 
2593 
2594 #ifdef CONFIG_MM_OWNER
2595 extern void mm_update_next_owner(struct mm_struct *mm);
2596 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2597 #else
2598 static inline void mm_update_next_owner(struct mm_struct *mm)
2599 {
2600 }
2601 
2602 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2603 {
2604 }
2605 #endif /* CONFIG_MM_OWNER */
2606 
2607 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2608 		unsigned int limit)
2609 {
2610 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2611 }
2612 
2613 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2614 		unsigned int limit)
2615 {
2616 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2617 }
2618 
2619 static inline unsigned long rlimit(unsigned int limit)
2620 {
2621 	return task_rlimit(current, limit);
2622 }
2623 
2624 static inline unsigned long rlimit_max(unsigned int limit)
2625 {
2626 	return task_rlimit_max(current, limit);
2627 }
2628 
2629 #endif /* __KERNEL__ */
2630 
2631 #endif
2632