xref: /linux/include/linux/sched.h (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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_softlockup_watchdog_sync(void);
314 extern void touch_all_softlockup_watchdogs(void);
315 extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
316 				    void __user *buffer,
317 				    size_t *lenp, loff_t *ppos);
318 extern unsigned int  softlockup_panic;
319 extern int softlockup_thresh;
320 #else
321 static inline void softlockup_tick(void)
322 {
323 }
324 static inline void touch_softlockup_watchdog(void)
325 {
326 }
327 static inline void touch_softlockup_watchdog_sync(void)
328 {
329 }
330 static inline void touch_all_softlockup_watchdogs(void)
331 {
332 }
333 #endif
334 
335 #ifdef CONFIG_DETECT_HUNG_TASK
336 extern unsigned int  sysctl_hung_task_panic;
337 extern unsigned long sysctl_hung_task_check_count;
338 extern unsigned long sysctl_hung_task_timeout_secs;
339 extern unsigned long sysctl_hung_task_warnings;
340 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
341 					 void __user *buffer,
342 					 size_t *lenp, loff_t *ppos);
343 #endif
344 
345 /* Attach to any functions which should be ignored in wchan output. */
346 #define __sched		__attribute__((__section__(".sched.text")))
347 
348 /* Linker adds these: start and end of __sched functions */
349 extern char __sched_text_start[], __sched_text_end[];
350 
351 /* Is this address in the __sched functions? */
352 extern int in_sched_functions(unsigned long addr);
353 
354 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
355 extern signed long schedule_timeout(signed long timeout);
356 extern signed long schedule_timeout_interruptible(signed long timeout);
357 extern signed long schedule_timeout_killable(signed long timeout);
358 extern signed long schedule_timeout_uninterruptible(signed long timeout);
359 asmlinkage void schedule(void);
360 extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
361 
362 struct nsproxy;
363 struct user_namespace;
364 
365 /*
366  * Default maximum number of active map areas, this limits the number of vmas
367  * per mm struct. Users can overwrite this number by sysctl but there is a
368  * problem.
369  *
370  * When a program's coredump is generated as ELF format, a section is created
371  * per a vma. In ELF, the number of sections is represented in unsigned short.
372  * This means the number of sections should be smaller than 65535 at coredump.
373  * Because the kernel adds some informative sections to a image of program at
374  * generating coredump, we need some margin. The number of extra sections is
375  * 1-3 now and depends on arch. We use "5" as safe margin, here.
376  */
377 #define MAPCOUNT_ELF_CORE_MARGIN	(5)
378 #define DEFAULT_MAX_MAP_COUNT	(USHORT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
379 
380 extern int sysctl_max_map_count;
381 
382 #include <linux/aio.h>
383 
384 #ifdef CONFIG_MMU
385 extern void arch_pick_mmap_layout(struct mm_struct *mm);
386 extern unsigned long
387 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
388 		       unsigned long, unsigned long);
389 extern unsigned long
390 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
391 			  unsigned long len, unsigned long pgoff,
392 			  unsigned long flags);
393 extern void arch_unmap_area(struct mm_struct *, unsigned long);
394 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
395 #else
396 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
397 #endif
398 
399 #if USE_SPLIT_PTLOCKS
400 /*
401  * The mm counters are not protected by its page_table_lock,
402  * so must be incremented atomically.
403  */
404 #define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
405 #define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
406 #define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
407 #define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
408 #define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
409 
410 #else  /* !USE_SPLIT_PTLOCKS */
411 /*
412  * The mm counters are protected by its page_table_lock,
413  * so can be incremented directly.
414  */
415 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
416 #define get_mm_counter(mm, member) ((mm)->_##member)
417 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
418 #define inc_mm_counter(mm, member) (mm)->_##member++
419 #define dec_mm_counter(mm, member) (mm)->_##member--
420 
421 #endif /* !USE_SPLIT_PTLOCKS */
422 
423 #define get_mm_rss(mm)					\
424 	(get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
425 #define update_hiwater_rss(mm)	do {			\
426 	unsigned long _rss = get_mm_rss(mm);		\
427 	if ((mm)->hiwater_rss < _rss)			\
428 		(mm)->hiwater_rss = _rss;		\
429 } while (0)
430 #define update_hiwater_vm(mm)	do {			\
431 	if ((mm)->hiwater_vm < (mm)->total_vm)		\
432 		(mm)->hiwater_vm = (mm)->total_vm;	\
433 } while (0)
434 
435 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
436 {
437 	return max(mm->hiwater_rss, get_mm_rss(mm));
438 }
439 
440 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
441 					 struct mm_struct *mm)
442 {
443 	unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
444 
445 	if (*maxrss < hiwater_rss)
446 		*maxrss = hiwater_rss;
447 }
448 
449 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
450 {
451 	return max(mm->hiwater_vm, mm->total_vm);
452 }
453 
454 extern void set_dumpable(struct mm_struct *mm, int value);
455 extern int get_dumpable(struct mm_struct *mm);
456 
457 /* mm flags */
458 /* dumpable bits */
459 #define MMF_DUMPABLE      0  /* core dump is permitted */
460 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
461 
462 #define MMF_DUMPABLE_BITS 2
463 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
464 
465 /* coredump filter bits */
466 #define MMF_DUMP_ANON_PRIVATE	2
467 #define MMF_DUMP_ANON_SHARED	3
468 #define MMF_DUMP_MAPPED_PRIVATE	4
469 #define MMF_DUMP_MAPPED_SHARED	5
470 #define MMF_DUMP_ELF_HEADERS	6
471 #define MMF_DUMP_HUGETLB_PRIVATE 7
472 #define MMF_DUMP_HUGETLB_SHARED  8
473 
474 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
475 #define MMF_DUMP_FILTER_BITS	7
476 #define MMF_DUMP_FILTER_MASK \
477 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
478 #define MMF_DUMP_FILTER_DEFAULT \
479 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
480 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
481 
482 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
483 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
484 #else
485 # define MMF_DUMP_MASK_DEFAULT_ELF	0
486 #endif
487 					/* leave room for more dump flags */
488 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
489 
490 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
491 
492 struct sighand_struct {
493 	atomic_t		count;
494 	struct k_sigaction	action[_NSIG];
495 	spinlock_t		siglock;
496 	wait_queue_head_t	signalfd_wqh;
497 };
498 
499 struct pacct_struct {
500 	int			ac_flag;
501 	long			ac_exitcode;
502 	unsigned long		ac_mem;
503 	cputime_t		ac_utime, ac_stime;
504 	unsigned long		ac_minflt, ac_majflt;
505 };
506 
507 struct cpu_itimer {
508 	cputime_t expires;
509 	cputime_t incr;
510 	u32 error;
511 	u32 incr_error;
512 };
513 
514 /**
515  * struct task_cputime - collected CPU time counts
516  * @utime:		time spent in user mode, in &cputime_t units
517  * @stime:		time spent in kernel mode, in &cputime_t units
518  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
519  *
520  * This structure groups together three kinds of CPU time that are
521  * tracked for threads and thread groups.  Most things considering
522  * CPU time want to group these counts together and treat all three
523  * of them in parallel.
524  */
525 struct task_cputime {
526 	cputime_t utime;
527 	cputime_t stime;
528 	unsigned long long sum_exec_runtime;
529 };
530 /* Alternate field names when used to cache expirations. */
531 #define prof_exp	stime
532 #define virt_exp	utime
533 #define sched_exp	sum_exec_runtime
534 
535 #define INIT_CPUTIME	\
536 	(struct task_cputime) {					\
537 		.utime = cputime_zero,				\
538 		.stime = cputime_zero,				\
539 		.sum_exec_runtime = 0,				\
540 	}
541 
542 /*
543  * Disable preemption until the scheduler is running.
544  * Reset by start_kernel()->sched_init()->init_idle().
545  *
546  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
547  * before the scheduler is active -- see should_resched().
548  */
549 #define INIT_PREEMPT_COUNT	(1 + PREEMPT_ACTIVE)
550 
551 /**
552  * struct thread_group_cputimer - thread group interval timer counts
553  * @cputime:		thread group interval timers.
554  * @running:		non-zero when there are timers running and
555  * 			@cputime receives updates.
556  * @lock:		lock for fields in this struct.
557  *
558  * This structure contains the version of task_cputime, above, that is
559  * used for thread group CPU timer calculations.
560  */
561 struct thread_group_cputimer {
562 	struct task_cputime cputime;
563 	int running;
564 	spinlock_t lock;
565 };
566 
567 /*
568  * NOTE! "signal_struct" does not have it's own
569  * locking, because a shared signal_struct always
570  * implies a shared sighand_struct, so locking
571  * sighand_struct is always a proper superset of
572  * the locking of signal_struct.
573  */
574 struct signal_struct {
575 	atomic_t		count;
576 	atomic_t		live;
577 
578 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
579 
580 	/* current thread group signal load-balancing target: */
581 	struct task_struct	*curr_target;
582 
583 	/* shared signal handling: */
584 	struct sigpending	shared_pending;
585 
586 	/* thread group exit support */
587 	int			group_exit_code;
588 	/* overloaded:
589 	 * - notify group_exit_task when ->count is equal to notify_count
590 	 * - everyone except group_exit_task is stopped during signal delivery
591 	 *   of fatal signals, group_exit_task processes the signal.
592 	 */
593 	int			notify_count;
594 	struct task_struct	*group_exit_task;
595 
596 	/* thread group stop support, overloads group_exit_code too */
597 	int			group_stop_count;
598 	unsigned int		flags; /* see SIGNAL_* flags below */
599 
600 	/* POSIX.1b Interval Timers */
601 	struct list_head posix_timers;
602 
603 	/* ITIMER_REAL timer for the process */
604 	struct hrtimer real_timer;
605 	struct pid *leader_pid;
606 	ktime_t it_real_incr;
607 
608 	/*
609 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
610 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
611 	 * values are defined to 0 and 1 respectively
612 	 */
613 	struct cpu_itimer it[2];
614 
615 	/*
616 	 * Thread group totals for process CPU timers.
617 	 * See thread_group_cputimer(), et al, for details.
618 	 */
619 	struct thread_group_cputimer cputimer;
620 
621 	/* Earliest-expiration cache. */
622 	struct task_cputime cputime_expires;
623 
624 	struct list_head cpu_timers[3];
625 
626 	struct pid *tty_old_pgrp;
627 
628 	/* boolean value for session group leader */
629 	int leader;
630 
631 	struct tty_struct *tty; /* NULL if no tty */
632 
633 	/*
634 	 * Cumulative resource counters for dead threads in the group,
635 	 * and for reaped dead child processes forked by this group.
636 	 * Live threads maintain their own counters and add to these
637 	 * in __exit_signal, except for the group leader.
638 	 */
639 	cputime_t utime, stime, cutime, cstime;
640 	cputime_t gtime;
641 	cputime_t cgtime;
642 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
643 	cputime_t prev_utime, prev_stime;
644 #endif
645 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
646 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
647 	unsigned long inblock, oublock, cinblock, coublock;
648 	unsigned long maxrss, cmaxrss;
649 	struct task_io_accounting ioac;
650 
651 	/*
652 	 * Cumulative ns of schedule CPU time fo dead threads in the
653 	 * group, not including a zombie group leader, (This only differs
654 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
655 	 * other than jiffies.)
656 	 */
657 	unsigned long long sum_sched_runtime;
658 
659 	/*
660 	 * We don't bother to synchronize most readers of this at all,
661 	 * because there is no reader checking a limit that actually needs
662 	 * to get both rlim_cur and rlim_max atomically, and either one
663 	 * alone is a single word that can safely be read normally.
664 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
665 	 * protect this instead of the siglock, because they really
666 	 * have no need to disable irqs.
667 	 */
668 	struct rlimit rlim[RLIM_NLIMITS];
669 
670 #ifdef CONFIG_BSD_PROCESS_ACCT
671 	struct pacct_struct pacct;	/* per-process accounting information */
672 #endif
673 #ifdef CONFIG_TASKSTATS
674 	struct taskstats *stats;
675 #endif
676 #ifdef CONFIG_AUDIT
677 	unsigned audit_tty;
678 	struct tty_audit_buf *tty_audit_buf;
679 #endif
680 
681 	int oom_adj;	/* OOM kill score adjustment (bit shift) */
682 };
683 
684 /* Context switch must be unlocked if interrupts are to be enabled */
685 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
686 # define __ARCH_WANT_UNLOCKED_CTXSW
687 #endif
688 
689 /*
690  * Bits in flags field of signal_struct.
691  */
692 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
693 #define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
694 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
695 #define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
696 /*
697  * Pending notifications to parent.
698  */
699 #define SIGNAL_CLD_STOPPED	0x00000010
700 #define SIGNAL_CLD_CONTINUED	0x00000020
701 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
702 
703 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
704 
705 /* If true, all threads except ->group_exit_task have pending SIGKILL */
706 static inline int signal_group_exit(const struct signal_struct *sig)
707 {
708 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
709 		(sig->group_exit_task != NULL);
710 }
711 
712 /*
713  * Some day this will be a full-fledged user tracking system..
714  */
715 struct user_struct {
716 	atomic_t __count;	/* reference count */
717 	atomic_t processes;	/* How many processes does this user have? */
718 	atomic_t files;		/* How many open files does this user have? */
719 	atomic_t sigpending;	/* How many pending signals does this user have? */
720 #ifdef CONFIG_INOTIFY_USER
721 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
722 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
723 #endif
724 #ifdef CONFIG_EPOLL
725 	atomic_t epoll_watches;	/* The number of file descriptors currently watched */
726 #endif
727 #ifdef CONFIG_POSIX_MQUEUE
728 	/* protected by mq_lock	*/
729 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
730 #endif
731 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
732 
733 #ifdef CONFIG_KEYS
734 	struct key *uid_keyring;	/* UID specific keyring */
735 	struct key *session_keyring;	/* UID's default session keyring */
736 #endif
737 
738 	/* Hash table maintenance information */
739 	struct hlist_node uidhash_node;
740 	uid_t uid;
741 	struct user_namespace *user_ns;
742 
743 #ifdef CONFIG_PERF_EVENTS
744 	atomic_long_t locked_vm;
745 #endif
746 };
747 
748 extern int uids_sysfs_init(void);
749 
750 extern struct user_struct *find_user(uid_t);
751 
752 extern struct user_struct root_user;
753 #define INIT_USER (&root_user)
754 
755 
756 struct backing_dev_info;
757 struct reclaim_state;
758 
759 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
760 struct sched_info {
761 	/* cumulative counters */
762 	unsigned long pcount;	      /* # of times run on this cpu */
763 	unsigned long long run_delay; /* time spent waiting on a runqueue */
764 
765 	/* timestamps */
766 	unsigned long long last_arrival,/* when we last ran on a cpu */
767 			   last_queued;	/* when we were last queued to run */
768 #ifdef CONFIG_SCHEDSTATS
769 	/* BKL stats */
770 	unsigned int bkl_count;
771 #endif
772 };
773 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
774 
775 #ifdef CONFIG_TASK_DELAY_ACCT
776 struct task_delay_info {
777 	spinlock_t	lock;
778 	unsigned int	flags;	/* Private per-task flags */
779 
780 	/* For each stat XXX, add following, aligned appropriately
781 	 *
782 	 * struct timespec XXX_start, XXX_end;
783 	 * u64 XXX_delay;
784 	 * u32 XXX_count;
785 	 *
786 	 * Atomicity of updates to XXX_delay, XXX_count protected by
787 	 * single lock above (split into XXX_lock if contention is an issue).
788 	 */
789 
790 	/*
791 	 * XXX_count is incremented on every XXX operation, the delay
792 	 * associated with the operation is added to XXX_delay.
793 	 * XXX_delay contains the accumulated delay time in nanoseconds.
794 	 */
795 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
796 	u64 blkio_delay;	/* wait for sync block io completion */
797 	u64 swapin_delay;	/* wait for swapin block io completion */
798 	u32 blkio_count;	/* total count of the number of sync block */
799 				/* io operations performed */
800 	u32 swapin_count;	/* total count of the number of swapin block */
801 				/* io operations performed */
802 
803 	struct timespec freepages_start, freepages_end;
804 	u64 freepages_delay;	/* wait for memory reclaim */
805 	u32 freepages_count;	/* total count of memory reclaim */
806 };
807 #endif	/* CONFIG_TASK_DELAY_ACCT */
808 
809 static inline int sched_info_on(void)
810 {
811 #ifdef CONFIG_SCHEDSTATS
812 	return 1;
813 #elif defined(CONFIG_TASK_DELAY_ACCT)
814 	extern int delayacct_on;
815 	return delayacct_on;
816 #else
817 	return 0;
818 #endif
819 }
820 
821 enum cpu_idle_type {
822 	CPU_IDLE,
823 	CPU_NOT_IDLE,
824 	CPU_NEWLY_IDLE,
825 	CPU_MAX_IDLE_TYPES
826 };
827 
828 /*
829  * sched-domains (multiprocessor balancing) declarations:
830  */
831 
832 /*
833  * Increase resolution of nice-level calculations:
834  */
835 #define SCHED_LOAD_SHIFT	10
836 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
837 
838 #define SCHED_LOAD_SCALE_FUZZ	SCHED_LOAD_SCALE
839 
840 #ifdef CONFIG_SMP
841 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
842 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
843 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
844 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
845 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
846 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
847 #define SD_PREFER_LOCAL		0x0040  /* Prefer to keep tasks local to this domain */
848 #define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
849 #define SD_POWERSAVINGS_BALANCE	0x0100	/* Balance for power savings */
850 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
851 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
852 
853 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
854 
855 enum powersavings_balance_level {
856 	POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
857 	POWERSAVINGS_BALANCE_BASIC,	/* Fill one thread/core/package
858 					 * first for long running threads
859 					 */
860 	POWERSAVINGS_BALANCE_WAKEUP,	/* Also bias task wakeups to semi-idle
861 					 * cpu package for power savings
862 					 */
863 	MAX_POWERSAVINGS_BALANCE_LEVELS
864 };
865 
866 extern int sched_mc_power_savings, sched_smt_power_savings;
867 
868 static inline int sd_balance_for_mc_power(void)
869 {
870 	if (sched_smt_power_savings)
871 		return SD_POWERSAVINGS_BALANCE;
872 
873 	if (!sched_mc_power_savings)
874 		return SD_PREFER_SIBLING;
875 
876 	return 0;
877 }
878 
879 static inline int sd_balance_for_package_power(void)
880 {
881 	if (sched_mc_power_savings | sched_smt_power_savings)
882 		return SD_POWERSAVINGS_BALANCE;
883 
884 	return SD_PREFER_SIBLING;
885 }
886 
887 /*
888  * Optimise SD flags for power savings:
889  * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings.
890  * Keep default SD flags if sched_{smt,mc}_power_saving=0
891  */
892 
893 static inline int sd_power_saving_flags(void)
894 {
895 	if (sched_mc_power_savings | sched_smt_power_savings)
896 		return SD_BALANCE_NEWIDLE;
897 
898 	return 0;
899 }
900 
901 struct sched_group {
902 	struct sched_group *next;	/* Must be a circular list */
903 
904 	/*
905 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
906 	 * single CPU.
907 	 */
908 	unsigned int cpu_power;
909 
910 	/*
911 	 * The CPUs this group covers.
912 	 *
913 	 * NOTE: this field is variable length. (Allocated dynamically
914 	 * by attaching extra space to the end of the structure,
915 	 * depending on how many CPUs the kernel has booted up with)
916 	 *
917 	 * It is also be embedded into static data structures at build
918 	 * time. (See 'struct static_sched_group' in kernel/sched.c)
919 	 */
920 	unsigned long cpumask[0];
921 };
922 
923 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
924 {
925 	return to_cpumask(sg->cpumask);
926 }
927 
928 enum sched_domain_level {
929 	SD_LV_NONE = 0,
930 	SD_LV_SIBLING,
931 	SD_LV_MC,
932 	SD_LV_CPU,
933 	SD_LV_NODE,
934 	SD_LV_ALLNODES,
935 	SD_LV_MAX
936 };
937 
938 struct sched_domain_attr {
939 	int relax_domain_level;
940 };
941 
942 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
943 	.relax_domain_level = -1,			\
944 }
945 
946 struct sched_domain {
947 	/* These fields must be setup */
948 	struct sched_domain *parent;	/* top domain must be null terminated */
949 	struct sched_domain *child;	/* bottom domain must be null terminated */
950 	struct sched_group *groups;	/* the balancing groups of the domain */
951 	unsigned long min_interval;	/* Minimum balance interval ms */
952 	unsigned long max_interval;	/* Maximum balance interval ms */
953 	unsigned int busy_factor;	/* less balancing by factor if busy */
954 	unsigned int imbalance_pct;	/* No balance until over watermark */
955 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
956 	unsigned int busy_idx;
957 	unsigned int idle_idx;
958 	unsigned int newidle_idx;
959 	unsigned int wake_idx;
960 	unsigned int forkexec_idx;
961 	unsigned int smt_gain;
962 	int flags;			/* See SD_* */
963 	enum sched_domain_level level;
964 
965 	/* Runtime fields. */
966 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
967 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
968 	unsigned int nr_balance_failed; /* initialise to 0 */
969 
970 	u64 last_update;
971 
972 #ifdef CONFIG_SCHEDSTATS
973 	/* load_balance() stats */
974 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
975 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
976 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
977 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
978 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
979 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
980 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
981 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
982 
983 	/* Active load balancing */
984 	unsigned int alb_count;
985 	unsigned int alb_failed;
986 	unsigned int alb_pushed;
987 
988 	/* SD_BALANCE_EXEC stats */
989 	unsigned int sbe_count;
990 	unsigned int sbe_balanced;
991 	unsigned int sbe_pushed;
992 
993 	/* SD_BALANCE_FORK stats */
994 	unsigned int sbf_count;
995 	unsigned int sbf_balanced;
996 	unsigned int sbf_pushed;
997 
998 	/* try_to_wake_up() stats */
999 	unsigned int ttwu_wake_remote;
1000 	unsigned int ttwu_move_affine;
1001 	unsigned int ttwu_move_balance;
1002 #endif
1003 #ifdef CONFIG_SCHED_DEBUG
1004 	char *name;
1005 #endif
1006 
1007 	/*
1008 	 * Span of all CPUs in this domain.
1009 	 *
1010 	 * NOTE: this field is variable length. (Allocated dynamically
1011 	 * by attaching extra space to the end of the structure,
1012 	 * depending on how many CPUs the kernel has booted up with)
1013 	 *
1014 	 * It is also be embedded into static data structures at build
1015 	 * time. (See 'struct static_sched_domain' in kernel/sched.c)
1016 	 */
1017 	unsigned long span[0];
1018 };
1019 
1020 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1021 {
1022 	return to_cpumask(sd->span);
1023 }
1024 
1025 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1026 				    struct sched_domain_attr *dattr_new);
1027 
1028 /* Allocate an array of sched domains, for partition_sched_domains(). */
1029 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1030 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1031 
1032 /* Test a flag in parent sched domain */
1033 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1034 {
1035 	if (sd->parent && (sd->parent->flags & flag))
1036 		return 1;
1037 
1038 	return 0;
1039 }
1040 
1041 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1042 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1043 
1044 #else /* CONFIG_SMP */
1045 
1046 struct sched_domain_attr;
1047 
1048 static inline void
1049 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1050 			struct sched_domain_attr *dattr_new)
1051 {
1052 }
1053 #endif	/* !CONFIG_SMP */
1054 
1055 
1056 struct io_context;			/* See blkdev.h */
1057 
1058 
1059 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1060 extern void prefetch_stack(struct task_struct *t);
1061 #else
1062 static inline void prefetch_stack(struct task_struct *t) { }
1063 #endif
1064 
1065 struct audit_context;		/* See audit.c */
1066 struct mempolicy;
1067 struct pipe_inode_info;
1068 struct uts_namespace;
1069 
1070 struct rq;
1071 struct sched_domain;
1072 
1073 /*
1074  * wake flags
1075  */
1076 #define WF_SYNC		0x01		/* waker goes to sleep after wakup */
1077 #define WF_FORK		0x02		/* child wakeup after fork */
1078 
1079 struct sched_class {
1080 	const struct sched_class *next;
1081 
1082 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup,
1083 			      bool head);
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 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1096 	void (*post_schedule) (struct rq *this_rq);
1097 	void (*task_waking) (struct rq *this_rq, struct task_struct *task);
1098 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1099 
1100 	void (*set_cpus_allowed)(struct task_struct *p,
1101 				 const struct cpumask *newmask);
1102 
1103 	void (*rq_online)(struct rq *rq);
1104 	void (*rq_offline)(struct rq *rq);
1105 #endif
1106 
1107 	void (*set_curr_task) (struct rq *rq);
1108 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1109 	void (*task_fork) (struct task_struct *p);
1110 
1111 	void (*switched_from) (struct rq *this_rq, struct task_struct *task,
1112 			       int running);
1113 	void (*switched_to) (struct rq *this_rq, struct task_struct *task,
1114 			     int running);
1115 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1116 			     int oldprio, int running);
1117 
1118 	unsigned int (*get_rr_interval) (struct rq *rq,
1119 					 struct task_struct *task);
1120 
1121 #ifdef CONFIG_FAIR_GROUP_SCHED
1122 	void (*moved_group) (struct task_struct *p, int on_rq);
1123 #endif
1124 };
1125 
1126 struct load_weight {
1127 	unsigned long weight, inv_weight;
1128 };
1129 
1130 /*
1131  * CFS stats for a schedulable entity (task, task-group etc)
1132  *
1133  * Current field usage histogram:
1134  *
1135  *     4 se->block_start
1136  *     4 se->run_node
1137  *     4 se->sleep_start
1138  *     6 se->load.weight
1139  */
1140 struct sched_entity {
1141 	struct load_weight	load;		/* for load-balancing */
1142 	struct rb_node		run_node;
1143 	struct list_head	group_node;
1144 	unsigned int		on_rq;
1145 
1146 	u64			exec_start;
1147 	u64			sum_exec_runtime;
1148 	u64			vruntime;
1149 	u64			prev_sum_exec_runtime;
1150 
1151 	u64			last_wakeup;
1152 	u64			avg_overlap;
1153 
1154 	u64			nr_migrations;
1155 
1156 	u64			start_runtime;
1157 	u64			avg_wakeup;
1158 
1159 #ifdef CONFIG_SCHEDSTATS
1160 	u64			wait_start;
1161 	u64			wait_max;
1162 	u64			wait_count;
1163 	u64			wait_sum;
1164 	u64			iowait_count;
1165 	u64			iowait_sum;
1166 
1167 	u64			sleep_start;
1168 	u64			sleep_max;
1169 	s64			sum_sleep_runtime;
1170 
1171 	u64			block_start;
1172 	u64			block_max;
1173 	u64			exec_max;
1174 	u64			slice_max;
1175 
1176 	u64			nr_migrations_cold;
1177 	u64			nr_failed_migrations_affine;
1178 	u64			nr_failed_migrations_running;
1179 	u64			nr_failed_migrations_hot;
1180 	u64			nr_forced_migrations;
1181 
1182 	u64			nr_wakeups;
1183 	u64			nr_wakeups_sync;
1184 	u64			nr_wakeups_migrate;
1185 	u64			nr_wakeups_local;
1186 	u64			nr_wakeups_remote;
1187 	u64			nr_wakeups_affine;
1188 	u64			nr_wakeups_affine_attempts;
1189 	u64			nr_wakeups_passive;
1190 	u64			nr_wakeups_idle;
1191 #endif
1192 
1193 #ifdef CONFIG_FAIR_GROUP_SCHED
1194 	struct sched_entity	*parent;
1195 	/* rq on which this entity is (to be) queued: */
1196 	struct cfs_rq		*cfs_rq;
1197 	/* rq "owned" by this entity/group: */
1198 	struct cfs_rq		*my_q;
1199 #endif
1200 };
1201 
1202 struct sched_rt_entity {
1203 	struct list_head run_list;
1204 	unsigned long timeout;
1205 	unsigned int time_slice;
1206 	int nr_cpus_allowed;
1207 
1208 	struct sched_rt_entity *back;
1209 #ifdef CONFIG_RT_GROUP_SCHED
1210 	struct sched_rt_entity	*parent;
1211 	/* rq on which this entity is (to be) queued: */
1212 	struct rt_rq		*rt_rq;
1213 	/* rq "owned" by this entity/group: */
1214 	struct rt_rq		*my_q;
1215 #endif
1216 };
1217 
1218 struct rcu_node;
1219 
1220 struct task_struct {
1221 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1222 	void *stack;
1223 	atomic_t usage;
1224 	unsigned int flags;	/* per process flags, defined below */
1225 	unsigned int ptrace;
1226 
1227 	int lock_depth;		/* BKL lock depth */
1228 
1229 #ifdef CONFIG_SMP
1230 #ifdef __ARCH_WANT_UNLOCKED_CTXSW
1231 	int oncpu;
1232 #endif
1233 #endif
1234 
1235 	int prio, static_prio, normal_prio;
1236 	unsigned int rt_priority;
1237 	const struct sched_class *sched_class;
1238 	struct sched_entity se;
1239 	struct sched_rt_entity rt;
1240 
1241 #ifdef CONFIG_PREEMPT_NOTIFIERS
1242 	/* list of struct preempt_notifier: */
1243 	struct hlist_head preempt_notifiers;
1244 #endif
1245 
1246 	/*
1247 	 * fpu_counter contains the number of consecutive context switches
1248 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1249 	 * saving becomes unlazy to save the trap. This is an unsigned char
1250 	 * so that after 256 times the counter wraps and the behavior turns
1251 	 * lazy again; this to deal with bursty apps that only use FPU for
1252 	 * a short time
1253 	 */
1254 	unsigned char fpu_counter;
1255 #ifdef CONFIG_BLK_DEV_IO_TRACE
1256 	unsigned int btrace_seq;
1257 #endif
1258 
1259 	unsigned int policy;
1260 	cpumask_t cpus_allowed;
1261 
1262 #ifdef CONFIG_TREE_PREEMPT_RCU
1263 	int rcu_read_lock_nesting;
1264 	char rcu_read_unlock_special;
1265 	struct rcu_node *rcu_blocked_node;
1266 	struct list_head rcu_node_entry;
1267 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1268 
1269 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1270 	struct sched_info sched_info;
1271 #endif
1272 
1273 	struct list_head tasks;
1274 	struct plist_node pushable_tasks;
1275 
1276 	struct mm_struct *mm, *active_mm;
1277 
1278 /* task state */
1279 	int exit_state;
1280 	int exit_code, exit_signal;
1281 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1282 	/* ??? */
1283 	unsigned int personality;
1284 	unsigned did_exec:1;
1285 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1286 				 * execve */
1287 	unsigned in_iowait:1;
1288 
1289 
1290 	/* Revert to default priority/policy when forking */
1291 	unsigned sched_reset_on_fork:1;
1292 
1293 	pid_t pid;
1294 	pid_t tgid;
1295 
1296 #ifdef CONFIG_CC_STACKPROTECTOR
1297 	/* Canary value for the -fstack-protector gcc feature */
1298 	unsigned long stack_canary;
1299 #endif
1300 
1301 	/*
1302 	 * pointers to (original) parent process, youngest child, younger sibling,
1303 	 * older sibling, respectively.  (p->father can be replaced with
1304 	 * p->real_parent->pid)
1305 	 */
1306 	struct task_struct *real_parent; /* real parent process */
1307 	struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1308 	/*
1309 	 * children/sibling forms the list of my natural children
1310 	 */
1311 	struct list_head children;	/* list of my children */
1312 	struct list_head sibling;	/* linkage in my parent's children list */
1313 	struct task_struct *group_leader;	/* threadgroup leader */
1314 
1315 	/*
1316 	 * ptraced is the list of tasks this task is using ptrace on.
1317 	 * This includes both natural children and PTRACE_ATTACH targets.
1318 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1319 	 */
1320 	struct list_head ptraced;
1321 	struct list_head ptrace_entry;
1322 
1323 	/*
1324 	 * This is the tracer handle for the ptrace BTS extension.
1325 	 * This field actually belongs to the ptracer task.
1326 	 */
1327 	struct bts_context *bts;
1328 
1329 	/* PID/PID hash table linkage. */
1330 	struct pid_link pids[PIDTYPE_MAX];
1331 	struct list_head thread_group;
1332 
1333 	struct completion *vfork_done;		/* for vfork() */
1334 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1335 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1336 
1337 	cputime_t utime, stime, utimescaled, stimescaled;
1338 	cputime_t gtime;
1339 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1340 	cputime_t prev_utime, prev_stime;
1341 #endif
1342 	unsigned long nvcsw, nivcsw; /* context switch counts */
1343 	struct timespec start_time; 		/* monotonic time */
1344 	struct timespec real_start_time;	/* boot based time */
1345 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1346 	unsigned long min_flt, maj_flt;
1347 
1348 	struct task_cputime cputime_expires;
1349 	struct list_head cpu_timers[3];
1350 
1351 /* process credentials */
1352 	const struct cred *real_cred;	/* objective and real subjective task
1353 					 * credentials (COW) */
1354 	const struct cred *cred;	/* effective (overridable) subjective task
1355 					 * credentials (COW) */
1356 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
1357 					 * credential calculations
1358 					 * (notably. ptrace) */
1359 	struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
1360 
1361 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1362 				     - access with [gs]et_task_comm (which lock
1363 				       it with task_lock())
1364 				     - initialized normally by setup_new_exec */
1365 /* file system info */
1366 	int link_count, total_link_count;
1367 #ifdef CONFIG_SYSVIPC
1368 /* ipc stuff */
1369 	struct sysv_sem sysvsem;
1370 #endif
1371 #ifdef CONFIG_DETECT_HUNG_TASK
1372 /* hung task detection */
1373 	unsigned long last_switch_count;
1374 #endif
1375 /* CPU-specific state of this task */
1376 	struct thread_struct thread;
1377 /* filesystem information */
1378 	struct fs_struct *fs;
1379 /* open file information */
1380 	struct files_struct *files;
1381 /* namespaces */
1382 	struct nsproxy *nsproxy;
1383 /* signal handlers */
1384 	struct signal_struct *signal;
1385 	struct sighand_struct *sighand;
1386 
1387 	sigset_t blocked, real_blocked;
1388 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1389 	struct sigpending pending;
1390 
1391 	unsigned long sas_ss_sp;
1392 	size_t sas_ss_size;
1393 	int (*notifier)(void *priv);
1394 	void *notifier_data;
1395 	sigset_t *notifier_mask;
1396 	struct audit_context *audit_context;
1397 #ifdef CONFIG_AUDITSYSCALL
1398 	uid_t loginuid;
1399 	unsigned int sessionid;
1400 #endif
1401 	seccomp_t seccomp;
1402 
1403 /* Thread group tracking */
1404    	u32 parent_exec_id;
1405    	u32 self_exec_id;
1406 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1407  * mempolicy */
1408 	spinlock_t alloc_lock;
1409 
1410 #ifdef CONFIG_GENERIC_HARDIRQS
1411 	/* IRQ handler threads */
1412 	struct irqaction *irqaction;
1413 #endif
1414 
1415 	/* Protection of the PI data structures: */
1416 	raw_spinlock_t pi_lock;
1417 
1418 #ifdef CONFIG_RT_MUTEXES
1419 	/* PI waiters blocked on a rt_mutex held by this task */
1420 	struct plist_head pi_waiters;
1421 	/* Deadlock detection and priority inheritance handling */
1422 	struct rt_mutex_waiter *pi_blocked_on;
1423 #endif
1424 
1425 #ifdef CONFIG_DEBUG_MUTEXES
1426 	/* mutex deadlock detection */
1427 	struct mutex_waiter *blocked_on;
1428 #endif
1429 #ifdef CONFIG_TRACE_IRQFLAGS
1430 	unsigned int irq_events;
1431 	unsigned long hardirq_enable_ip;
1432 	unsigned long hardirq_disable_ip;
1433 	unsigned int hardirq_enable_event;
1434 	unsigned int hardirq_disable_event;
1435 	int hardirqs_enabled;
1436 	int hardirq_context;
1437 	unsigned long softirq_disable_ip;
1438 	unsigned long softirq_enable_ip;
1439 	unsigned int softirq_disable_event;
1440 	unsigned int softirq_enable_event;
1441 	int softirqs_enabled;
1442 	int softirq_context;
1443 #endif
1444 #ifdef CONFIG_LOCKDEP
1445 # define MAX_LOCK_DEPTH 48UL
1446 	u64 curr_chain_key;
1447 	int lockdep_depth;
1448 	unsigned int lockdep_recursion;
1449 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1450 	gfp_t lockdep_reclaim_gfp;
1451 #endif
1452 
1453 /* journalling filesystem info */
1454 	void *journal_info;
1455 
1456 /* stacked block device info */
1457 	struct bio *bio_list, **bio_tail;
1458 
1459 /* VM state */
1460 	struct reclaim_state *reclaim_state;
1461 
1462 	struct backing_dev_info *backing_dev_info;
1463 
1464 	struct io_context *io_context;
1465 
1466 	unsigned long ptrace_message;
1467 	siginfo_t *last_siginfo; /* For ptrace use.  */
1468 	struct task_io_accounting ioac;
1469 #if defined(CONFIG_TASK_XACCT)
1470 	u64 acct_rss_mem1;	/* accumulated rss usage */
1471 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1472 	cputime_t acct_timexpd;	/* stime + utime since last update */
1473 #endif
1474 #ifdef CONFIG_CPUSETS
1475 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1476 	int cpuset_mem_spread_rotor;
1477 #endif
1478 #ifdef CONFIG_CGROUPS
1479 	/* Control Group info protected by css_set_lock */
1480 	struct css_set *cgroups;
1481 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1482 	struct list_head cg_list;
1483 #endif
1484 #ifdef CONFIG_FUTEX
1485 	struct robust_list_head __user *robust_list;
1486 #ifdef CONFIG_COMPAT
1487 	struct compat_robust_list_head __user *compat_robust_list;
1488 #endif
1489 	struct list_head pi_state_list;
1490 	struct futex_pi_state *pi_state_cache;
1491 #endif
1492 #ifdef CONFIG_PERF_EVENTS
1493 	struct perf_event_context *perf_event_ctxp;
1494 	struct mutex perf_event_mutex;
1495 	struct list_head perf_event_list;
1496 #endif
1497 #ifdef CONFIG_NUMA
1498 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1499 	short il_next;
1500 #endif
1501 	atomic_t fs_excl;	/* holding fs exclusive resources */
1502 	struct rcu_head rcu;
1503 
1504 	/*
1505 	 * cache last used pipe for splice
1506 	 */
1507 	struct pipe_inode_info *splice_pipe;
1508 #ifdef	CONFIG_TASK_DELAY_ACCT
1509 	struct task_delay_info *delays;
1510 #endif
1511 #ifdef CONFIG_FAULT_INJECTION
1512 	int make_it_fail;
1513 #endif
1514 	struct prop_local_single dirties;
1515 #ifdef CONFIG_LATENCYTOP
1516 	int latency_record_count;
1517 	struct latency_record latency_record[LT_SAVECOUNT];
1518 #endif
1519 	/*
1520 	 * time slack values; these are used to round up poll() and
1521 	 * select() etc timeout values. These are in nanoseconds.
1522 	 */
1523 	unsigned long timer_slack_ns;
1524 	unsigned long default_timer_slack_ns;
1525 
1526 	struct list_head	*scm_work_list;
1527 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1528 	/* Index of current stored adress in ret_stack */
1529 	int curr_ret_stack;
1530 	/* Stack of return addresses for return function tracing */
1531 	struct ftrace_ret_stack	*ret_stack;
1532 	/* time stamp for last schedule */
1533 	unsigned long long ftrace_timestamp;
1534 	/*
1535 	 * Number of functions that haven't been traced
1536 	 * because of depth overrun.
1537 	 */
1538 	atomic_t trace_overrun;
1539 	/* Pause for the tracing */
1540 	atomic_t tracing_graph_pause;
1541 #endif
1542 #ifdef CONFIG_TRACING
1543 	/* state flags for use by tracers */
1544 	unsigned long trace;
1545 	/* bitmask of trace recursion */
1546 	unsigned long trace_recursion;
1547 #endif /* CONFIG_TRACING */
1548 	unsigned long stack_start;
1549 #ifdef CONFIG_CGROUP_MEM_RES_CTLR /* memcg uses this to do batch job */
1550 	struct memcg_batch_info {
1551 		int do_batch;	/* incremented when batch uncharge started */
1552 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1553 		unsigned long bytes; 		/* uncharged usage */
1554 		unsigned long memsw_bytes; /* uncharged mem+swap usage */
1555 	} memcg_batch;
1556 #endif
1557 };
1558 
1559 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1560 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1561 
1562 /*
1563  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1564  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1565  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1566  * values are inverted: lower p->prio value means higher priority.
1567  *
1568  * The MAX_USER_RT_PRIO value allows the actual maximum
1569  * RT priority to be separate from the value exported to
1570  * user-space.  This allows kernel threads to set their
1571  * priority to a value higher than any user task. Note:
1572  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1573  */
1574 
1575 #define MAX_USER_RT_PRIO	100
1576 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1577 
1578 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1579 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1580 
1581 static inline int rt_prio(int prio)
1582 {
1583 	if (unlikely(prio < MAX_RT_PRIO))
1584 		return 1;
1585 	return 0;
1586 }
1587 
1588 static inline int rt_task(struct task_struct *p)
1589 {
1590 	return rt_prio(p->prio);
1591 }
1592 
1593 static inline struct pid *task_pid(struct task_struct *task)
1594 {
1595 	return task->pids[PIDTYPE_PID].pid;
1596 }
1597 
1598 static inline struct pid *task_tgid(struct task_struct *task)
1599 {
1600 	return task->group_leader->pids[PIDTYPE_PID].pid;
1601 }
1602 
1603 /*
1604  * Without tasklist or rcu lock it is not safe to dereference
1605  * the result of task_pgrp/task_session even if task == current,
1606  * we can race with another thread doing sys_setsid/sys_setpgid.
1607  */
1608 static inline struct pid *task_pgrp(struct task_struct *task)
1609 {
1610 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1611 }
1612 
1613 static inline struct pid *task_session(struct task_struct *task)
1614 {
1615 	return task->group_leader->pids[PIDTYPE_SID].pid;
1616 }
1617 
1618 struct pid_namespace;
1619 
1620 /*
1621  * the helpers to get the task's different pids as they are seen
1622  * from various namespaces
1623  *
1624  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1625  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1626  *                     current.
1627  * task_xid_nr_ns()  : id seen from the ns specified;
1628  *
1629  * set_task_vxid()   : assigns a virtual id to a task;
1630  *
1631  * see also pid_nr() etc in include/linux/pid.h
1632  */
1633 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1634 			struct pid_namespace *ns);
1635 
1636 static inline pid_t task_pid_nr(struct task_struct *tsk)
1637 {
1638 	return tsk->pid;
1639 }
1640 
1641 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1642 					struct pid_namespace *ns)
1643 {
1644 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1645 }
1646 
1647 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1648 {
1649 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1650 }
1651 
1652 
1653 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1654 {
1655 	return tsk->tgid;
1656 }
1657 
1658 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1659 
1660 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1661 {
1662 	return pid_vnr(task_tgid(tsk));
1663 }
1664 
1665 
1666 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1667 					struct pid_namespace *ns)
1668 {
1669 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1670 }
1671 
1672 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1673 {
1674 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1675 }
1676 
1677 
1678 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1679 					struct pid_namespace *ns)
1680 {
1681 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1682 }
1683 
1684 static inline pid_t task_session_vnr(struct task_struct *tsk)
1685 {
1686 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1687 }
1688 
1689 /* obsolete, do not use */
1690 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1691 {
1692 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1693 }
1694 
1695 /**
1696  * pid_alive - check that a task structure is not stale
1697  * @p: Task structure to be checked.
1698  *
1699  * Test if a process is not yet dead (at most zombie state)
1700  * If pid_alive fails, then pointers within the task structure
1701  * can be stale and must not be dereferenced.
1702  */
1703 static inline int pid_alive(struct task_struct *p)
1704 {
1705 	return p->pids[PIDTYPE_PID].pid != NULL;
1706 }
1707 
1708 /**
1709  * is_global_init - check if a task structure is init
1710  * @tsk: Task structure to be checked.
1711  *
1712  * Check if a task structure is the first user space task the kernel created.
1713  */
1714 static inline int is_global_init(struct task_struct *tsk)
1715 {
1716 	return tsk->pid == 1;
1717 }
1718 
1719 /*
1720  * is_container_init:
1721  * check whether in the task is init in its own pid namespace.
1722  */
1723 extern int is_container_init(struct task_struct *tsk);
1724 
1725 extern struct pid *cad_pid;
1726 
1727 extern void free_task(struct task_struct *tsk);
1728 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1729 
1730 extern void __put_task_struct(struct task_struct *t);
1731 
1732 static inline void put_task_struct(struct task_struct *t)
1733 {
1734 	if (atomic_dec_and_test(&t->usage))
1735 		__put_task_struct(t);
1736 }
1737 
1738 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1739 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1740 
1741 /*
1742  * Per process flags
1743  */
1744 #define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
1745 					/* Not implemented yet, only for 486*/
1746 #define PF_STARTING	0x00000002	/* being created */
1747 #define PF_EXITING	0x00000004	/* getting shut down */
1748 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1749 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1750 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1751 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1752 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1753 #define PF_DUMPCORE	0x00000200	/* dumped core */
1754 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1755 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1756 #define PF_FLUSHER	0x00001000	/* responsible for disk writeback */
1757 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1758 #define PF_FREEZING	0x00004000	/* freeze in progress. do not account to load */
1759 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1760 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1761 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1762 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1763 #define PF_OOM_ORIGIN	0x00080000	/* Allocating much memory to others */
1764 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1765 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1766 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1767 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1768 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1769 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1770 #define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1771 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1772 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1773 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1774 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezeable */
1775 #define PF_FREEZER_NOSIG 0x80000000	/* Freezer won't send signals to it */
1776 
1777 /*
1778  * Only the _current_ task can read/write to tsk->flags, but other
1779  * tasks can access tsk->flags in readonly mode for example
1780  * with tsk_used_math (like during threaded core dumping).
1781  * There is however an exception to this rule during ptrace
1782  * or during fork: the ptracer task is allowed to write to the
1783  * child->flags of its traced child (same goes for fork, the parent
1784  * can write to the child->flags), because we're guaranteed the
1785  * child is not running and in turn not changing child->flags
1786  * at the same time the parent does it.
1787  */
1788 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1789 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1790 #define clear_used_math() clear_stopped_child_used_math(current)
1791 #define set_used_math() set_stopped_child_used_math(current)
1792 #define conditional_stopped_child_used_math(condition, child) \
1793 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1794 #define conditional_used_math(condition) \
1795 	conditional_stopped_child_used_math(condition, current)
1796 #define copy_to_stopped_child_used_math(child) \
1797 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1798 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1799 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1800 #define used_math() tsk_used_math(current)
1801 
1802 #ifdef CONFIG_TREE_PREEMPT_RCU
1803 
1804 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1805 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1806 
1807 static inline void rcu_copy_process(struct task_struct *p)
1808 {
1809 	p->rcu_read_lock_nesting = 0;
1810 	p->rcu_read_unlock_special = 0;
1811 	p->rcu_blocked_node = NULL;
1812 	INIT_LIST_HEAD(&p->rcu_node_entry);
1813 }
1814 
1815 #else
1816 
1817 static inline void rcu_copy_process(struct task_struct *p)
1818 {
1819 }
1820 
1821 #endif
1822 
1823 #ifdef CONFIG_SMP
1824 extern int set_cpus_allowed_ptr(struct task_struct *p,
1825 				const struct cpumask *new_mask);
1826 #else
1827 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1828 				       const struct cpumask *new_mask)
1829 {
1830 	if (!cpumask_test_cpu(0, new_mask))
1831 		return -EINVAL;
1832 	return 0;
1833 }
1834 #endif
1835 
1836 #ifndef CONFIG_CPUMASK_OFFSTACK
1837 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1838 {
1839 	return set_cpus_allowed_ptr(p, &new_mask);
1840 }
1841 #endif
1842 
1843 /*
1844  * Architectures can set this to 1 if they have specified
1845  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1846  * but then during bootup it turns out that sched_clock()
1847  * is reliable after all:
1848  */
1849 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1850 extern int sched_clock_stable;
1851 #endif
1852 
1853 /* ftrace calls sched_clock() directly */
1854 extern unsigned long long notrace sched_clock(void);
1855 
1856 extern void sched_clock_init(void);
1857 extern u64 sched_clock_cpu(int cpu);
1858 
1859 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1860 static inline void sched_clock_tick(void)
1861 {
1862 }
1863 
1864 static inline void sched_clock_idle_sleep_event(void)
1865 {
1866 }
1867 
1868 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1869 {
1870 }
1871 #else
1872 extern void sched_clock_tick(void);
1873 extern void sched_clock_idle_sleep_event(void);
1874 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1875 #endif
1876 
1877 /*
1878  * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
1879  * clock constructed from sched_clock():
1880  */
1881 extern unsigned long long cpu_clock(int cpu);
1882 
1883 extern unsigned long long
1884 task_sched_runtime(struct task_struct *task);
1885 extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
1886 
1887 /* sched_exec is called by processes performing an exec */
1888 #ifdef CONFIG_SMP
1889 extern void sched_exec(void);
1890 #else
1891 #define sched_exec()   {}
1892 #endif
1893 
1894 extern void sched_clock_idle_sleep_event(void);
1895 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1896 
1897 #ifdef CONFIG_HOTPLUG_CPU
1898 extern void idle_task_exit(void);
1899 #else
1900 static inline void idle_task_exit(void) {}
1901 #endif
1902 
1903 extern void sched_idle_next(void);
1904 
1905 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1906 extern void wake_up_idle_cpu(int cpu);
1907 #else
1908 static inline void wake_up_idle_cpu(int cpu) { }
1909 #endif
1910 
1911 extern unsigned int sysctl_sched_latency;
1912 extern unsigned int sysctl_sched_min_granularity;
1913 extern unsigned int sysctl_sched_wakeup_granularity;
1914 extern unsigned int sysctl_sched_shares_ratelimit;
1915 extern unsigned int sysctl_sched_shares_thresh;
1916 extern unsigned int sysctl_sched_child_runs_first;
1917 
1918 enum sched_tunable_scaling {
1919 	SCHED_TUNABLESCALING_NONE,
1920 	SCHED_TUNABLESCALING_LOG,
1921 	SCHED_TUNABLESCALING_LINEAR,
1922 	SCHED_TUNABLESCALING_END,
1923 };
1924 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
1925 
1926 #ifdef CONFIG_SCHED_DEBUG
1927 extern unsigned int sysctl_sched_migration_cost;
1928 extern unsigned int sysctl_sched_nr_migrate;
1929 extern unsigned int sysctl_sched_time_avg;
1930 extern unsigned int sysctl_timer_migration;
1931 
1932 int sched_proc_update_handler(struct ctl_table *table, int write,
1933 		void __user *buffer, size_t *length,
1934 		loff_t *ppos);
1935 #endif
1936 #ifdef CONFIG_SCHED_DEBUG
1937 static inline unsigned int get_sysctl_timer_migration(void)
1938 {
1939 	return sysctl_timer_migration;
1940 }
1941 #else
1942 static inline unsigned int get_sysctl_timer_migration(void)
1943 {
1944 	return 1;
1945 }
1946 #endif
1947 extern unsigned int sysctl_sched_rt_period;
1948 extern int sysctl_sched_rt_runtime;
1949 
1950 int sched_rt_handler(struct ctl_table *table, int write,
1951 		void __user *buffer, size_t *lenp,
1952 		loff_t *ppos);
1953 
1954 extern unsigned int sysctl_sched_compat_yield;
1955 
1956 #ifdef CONFIG_RT_MUTEXES
1957 extern int rt_mutex_getprio(struct task_struct *p);
1958 extern void rt_mutex_setprio(struct task_struct *p, int prio);
1959 extern void rt_mutex_adjust_pi(struct task_struct *p);
1960 #else
1961 static inline int rt_mutex_getprio(struct task_struct *p)
1962 {
1963 	return p->normal_prio;
1964 }
1965 # define rt_mutex_adjust_pi(p)		do { } while (0)
1966 #endif
1967 
1968 extern void set_user_nice(struct task_struct *p, long nice);
1969 extern int task_prio(const struct task_struct *p);
1970 extern int task_nice(const struct task_struct *p);
1971 extern int can_nice(const struct task_struct *p, const int nice);
1972 extern int task_curr(const struct task_struct *p);
1973 extern int idle_cpu(int cpu);
1974 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1975 extern int sched_setscheduler_nocheck(struct task_struct *, int,
1976 				      struct sched_param *);
1977 extern struct task_struct *idle_task(int cpu);
1978 extern struct task_struct *curr_task(int cpu);
1979 extern void set_curr_task(int cpu, struct task_struct *p);
1980 
1981 void yield(void);
1982 
1983 /*
1984  * The default (Linux) execution domain.
1985  */
1986 extern struct exec_domain	default_exec_domain;
1987 
1988 union thread_union {
1989 	struct thread_info thread_info;
1990 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1991 };
1992 
1993 #ifndef __HAVE_ARCH_KSTACK_END
1994 static inline int kstack_end(void *addr)
1995 {
1996 	/* Reliable end of stack detection:
1997 	 * Some APM bios versions misalign the stack
1998 	 */
1999 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2000 }
2001 #endif
2002 
2003 extern union thread_union init_thread_union;
2004 extern struct task_struct init_task;
2005 
2006 extern struct   mm_struct init_mm;
2007 
2008 extern struct pid_namespace init_pid_ns;
2009 
2010 /*
2011  * find a task by one of its numerical ids
2012  *
2013  * find_task_by_pid_ns():
2014  *      finds a task by its pid in the specified namespace
2015  * find_task_by_vpid():
2016  *      finds a task by its virtual pid
2017  *
2018  * see also find_vpid() etc in include/linux/pid.h
2019  */
2020 
2021 extern struct task_struct *find_task_by_vpid(pid_t nr);
2022 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2023 		struct pid_namespace *ns);
2024 
2025 extern void __set_special_pids(struct pid *pid);
2026 
2027 /* per-UID process charging. */
2028 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
2029 static inline struct user_struct *get_uid(struct user_struct *u)
2030 {
2031 	atomic_inc(&u->__count);
2032 	return u;
2033 }
2034 extern void free_uid(struct user_struct *);
2035 extern void release_uids(struct user_namespace *ns);
2036 
2037 #include <asm/current.h>
2038 
2039 extern void do_timer(unsigned long ticks);
2040 
2041 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2042 extern int wake_up_process(struct task_struct *tsk);
2043 extern void wake_up_new_task(struct task_struct *tsk,
2044 				unsigned long clone_flags);
2045 #ifdef CONFIG_SMP
2046  extern void kick_process(struct task_struct *tsk);
2047 #else
2048  static inline void kick_process(struct task_struct *tsk) { }
2049 #endif
2050 extern void sched_fork(struct task_struct *p, int clone_flags);
2051 extern void sched_dead(struct task_struct *p);
2052 
2053 extern void proc_caches_init(void);
2054 extern void flush_signals(struct task_struct *);
2055 extern void __flush_signals(struct task_struct *);
2056 extern void ignore_signals(struct task_struct *);
2057 extern void flush_signal_handlers(struct task_struct *, int force_default);
2058 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2059 
2060 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2061 {
2062 	unsigned long flags;
2063 	int ret;
2064 
2065 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2066 	ret = dequeue_signal(tsk, mask, info);
2067 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2068 
2069 	return ret;
2070 }
2071 
2072 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2073 			      sigset_t *mask);
2074 extern void unblock_all_signals(void);
2075 extern void release_task(struct task_struct * p);
2076 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2077 extern int force_sigsegv(int, struct task_struct *);
2078 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2079 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2080 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2081 extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
2082 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2083 extern int kill_pid(struct pid *pid, int sig, int priv);
2084 extern int kill_proc_info(int, struct siginfo *, pid_t);
2085 extern int do_notify_parent(struct task_struct *, int);
2086 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2087 extern void force_sig(int, struct task_struct *);
2088 extern int send_sig(int, struct task_struct *, int);
2089 extern void zap_other_threads(struct task_struct *p);
2090 extern struct sigqueue *sigqueue_alloc(void);
2091 extern void sigqueue_free(struct sigqueue *);
2092 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2093 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2094 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2095 
2096 static inline int kill_cad_pid(int sig, int priv)
2097 {
2098 	return kill_pid(cad_pid, sig, priv);
2099 }
2100 
2101 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2102 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2103 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2104 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2105 
2106 /*
2107  * True if we are on the alternate signal stack.
2108  */
2109 static inline int on_sig_stack(unsigned long sp)
2110 {
2111 #ifdef CONFIG_STACK_GROWSUP
2112 	return sp >= current->sas_ss_sp &&
2113 		sp - current->sas_ss_sp < current->sas_ss_size;
2114 #else
2115 	return sp > current->sas_ss_sp &&
2116 		sp - current->sas_ss_sp <= current->sas_ss_size;
2117 #endif
2118 }
2119 
2120 static inline int sas_ss_flags(unsigned long sp)
2121 {
2122 	return (current->sas_ss_size == 0 ? SS_DISABLE
2123 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2124 }
2125 
2126 /*
2127  * Routines for handling mm_structs
2128  */
2129 extern struct mm_struct * mm_alloc(void);
2130 
2131 /* mmdrop drops the mm and the page tables */
2132 extern void __mmdrop(struct mm_struct *);
2133 static inline void mmdrop(struct mm_struct * mm)
2134 {
2135 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2136 		__mmdrop(mm);
2137 }
2138 
2139 /* mmput gets rid of the mappings and all user-space */
2140 extern void mmput(struct mm_struct *);
2141 /* Grab a reference to a task's mm, if it is not already going away */
2142 extern struct mm_struct *get_task_mm(struct task_struct *task);
2143 /* Remove the current tasks stale references to the old mm_struct */
2144 extern void mm_release(struct task_struct *, struct mm_struct *);
2145 /* Allocate a new mm structure and copy contents from tsk->mm */
2146 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2147 
2148 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2149 			struct task_struct *, struct pt_regs *);
2150 extern void flush_thread(void);
2151 extern void exit_thread(void);
2152 
2153 extern void exit_files(struct task_struct *);
2154 extern void __cleanup_signal(struct signal_struct *);
2155 extern void __cleanup_sighand(struct sighand_struct *);
2156 
2157 extern void exit_itimers(struct signal_struct *);
2158 extern void flush_itimer_signals(void);
2159 
2160 extern NORET_TYPE void do_group_exit(int);
2161 
2162 extern void daemonize(const char *, ...);
2163 extern int allow_signal(int);
2164 extern int disallow_signal(int);
2165 
2166 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
2167 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2168 struct task_struct *fork_idle(int);
2169 
2170 extern void set_task_comm(struct task_struct *tsk, char *from);
2171 extern char *get_task_comm(char *to, struct task_struct *tsk);
2172 
2173 #ifdef CONFIG_SMP
2174 extern void wait_task_context_switch(struct task_struct *p);
2175 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2176 #else
2177 static inline void wait_task_context_switch(struct task_struct *p) {}
2178 static inline unsigned long wait_task_inactive(struct task_struct *p,
2179 					       long match_state)
2180 {
2181 	return 1;
2182 }
2183 #endif
2184 
2185 #define next_task(p) \
2186 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2187 
2188 #define for_each_process(p) \
2189 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2190 
2191 extern bool current_is_single_threaded(void);
2192 
2193 /*
2194  * Careful: do_each_thread/while_each_thread is a double loop so
2195  *          'break' will not work as expected - use goto instead.
2196  */
2197 #define do_each_thread(g, t) \
2198 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2199 
2200 #define while_each_thread(g, t) \
2201 	while ((t = next_thread(t)) != g)
2202 
2203 /* de_thread depends on thread_group_leader not being a pid based check */
2204 #define thread_group_leader(p)	(p == p->group_leader)
2205 
2206 /* Do to the insanities of de_thread it is possible for a process
2207  * to have the pid of the thread group leader without actually being
2208  * the thread group leader.  For iteration through the pids in proc
2209  * all we care about is that we have a task with the appropriate
2210  * pid, we don't actually care if we have the right task.
2211  */
2212 static inline int has_group_leader_pid(struct task_struct *p)
2213 {
2214 	return p->pid == p->tgid;
2215 }
2216 
2217 static inline
2218 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2219 {
2220 	return p1->tgid == p2->tgid;
2221 }
2222 
2223 static inline struct task_struct *next_thread(const struct task_struct *p)
2224 {
2225 	return list_entry_rcu(p->thread_group.next,
2226 			      struct task_struct, thread_group);
2227 }
2228 
2229 static inline int thread_group_empty(struct task_struct *p)
2230 {
2231 	return list_empty(&p->thread_group);
2232 }
2233 
2234 #define delay_group_leader(p) \
2235 		(thread_group_leader(p) && !thread_group_empty(p))
2236 
2237 static inline int task_detached(struct task_struct *p)
2238 {
2239 	return p->exit_signal == -1;
2240 }
2241 
2242 /*
2243  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2244  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2245  * pins the final release of task.io_context.  Also protects ->cpuset and
2246  * ->cgroup.subsys[].
2247  *
2248  * Nests both inside and outside of read_lock(&tasklist_lock).
2249  * It must not be nested with write_lock_irq(&tasklist_lock),
2250  * neither inside nor outside.
2251  */
2252 static inline void task_lock(struct task_struct *p)
2253 {
2254 	spin_lock(&p->alloc_lock);
2255 }
2256 
2257 static inline void task_unlock(struct task_struct *p)
2258 {
2259 	spin_unlock(&p->alloc_lock);
2260 }
2261 
2262 extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2263 							unsigned long *flags);
2264 
2265 static inline void unlock_task_sighand(struct task_struct *tsk,
2266 						unsigned long *flags)
2267 {
2268 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2269 }
2270 
2271 #ifndef __HAVE_THREAD_FUNCTIONS
2272 
2273 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2274 #define task_stack_page(task)	((task)->stack)
2275 
2276 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2277 {
2278 	*task_thread_info(p) = *task_thread_info(org);
2279 	task_thread_info(p)->task = p;
2280 }
2281 
2282 static inline unsigned long *end_of_stack(struct task_struct *p)
2283 {
2284 	return (unsigned long *)(task_thread_info(p) + 1);
2285 }
2286 
2287 #endif
2288 
2289 static inline int object_is_on_stack(void *obj)
2290 {
2291 	void *stack = task_stack_page(current);
2292 
2293 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2294 }
2295 
2296 extern void thread_info_cache_init(void);
2297 
2298 #ifdef CONFIG_DEBUG_STACK_USAGE
2299 static inline unsigned long stack_not_used(struct task_struct *p)
2300 {
2301 	unsigned long *n = end_of_stack(p);
2302 
2303 	do { 	/* Skip over canary */
2304 		n++;
2305 	} while (!*n);
2306 
2307 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2308 }
2309 #endif
2310 
2311 /* set thread flags in other task's structures
2312  * - see asm/thread_info.h for TIF_xxxx flags available
2313  */
2314 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2315 {
2316 	set_ti_thread_flag(task_thread_info(tsk), flag);
2317 }
2318 
2319 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2320 {
2321 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2322 }
2323 
2324 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2325 {
2326 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2327 }
2328 
2329 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2330 {
2331 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2332 }
2333 
2334 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2335 {
2336 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2337 }
2338 
2339 static inline void set_tsk_need_resched(struct task_struct *tsk)
2340 {
2341 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2342 }
2343 
2344 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2345 {
2346 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2347 }
2348 
2349 static inline int test_tsk_need_resched(struct task_struct *tsk)
2350 {
2351 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2352 }
2353 
2354 static inline int restart_syscall(void)
2355 {
2356 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2357 	return -ERESTARTNOINTR;
2358 }
2359 
2360 static inline int signal_pending(struct task_struct *p)
2361 {
2362 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2363 }
2364 
2365 static inline int __fatal_signal_pending(struct task_struct *p)
2366 {
2367 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2368 }
2369 
2370 static inline int fatal_signal_pending(struct task_struct *p)
2371 {
2372 	return signal_pending(p) && __fatal_signal_pending(p);
2373 }
2374 
2375 static inline int signal_pending_state(long state, struct task_struct *p)
2376 {
2377 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2378 		return 0;
2379 	if (!signal_pending(p))
2380 		return 0;
2381 
2382 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2383 }
2384 
2385 static inline int need_resched(void)
2386 {
2387 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2388 }
2389 
2390 /*
2391  * cond_resched() and cond_resched_lock(): latency reduction via
2392  * explicit rescheduling in places that are safe. The return
2393  * value indicates whether a reschedule was done in fact.
2394  * cond_resched_lock() will drop the spinlock before scheduling,
2395  * cond_resched_softirq() will enable bhs before scheduling.
2396  */
2397 extern int _cond_resched(void);
2398 
2399 #define cond_resched() ({			\
2400 	__might_sleep(__FILE__, __LINE__, 0);	\
2401 	_cond_resched();			\
2402 })
2403 
2404 extern int __cond_resched_lock(spinlock_t *lock);
2405 
2406 #ifdef CONFIG_PREEMPT
2407 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2408 #else
2409 #define PREEMPT_LOCK_OFFSET	0
2410 #endif
2411 
2412 #define cond_resched_lock(lock) ({				\
2413 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2414 	__cond_resched_lock(lock);				\
2415 })
2416 
2417 extern int __cond_resched_softirq(void);
2418 
2419 #define cond_resched_softirq() ({				\
2420 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_OFFSET);	\
2421 	__cond_resched_softirq();				\
2422 })
2423 
2424 /*
2425  * Does a critical section need to be broken due to another
2426  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2427  * but a general need for low latency)
2428  */
2429 static inline int spin_needbreak(spinlock_t *lock)
2430 {
2431 #ifdef CONFIG_PREEMPT
2432 	return spin_is_contended(lock);
2433 #else
2434 	return 0;
2435 #endif
2436 }
2437 
2438 /*
2439  * Thread group CPU time accounting.
2440  */
2441 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2442 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2443 
2444 static inline void thread_group_cputime_init(struct signal_struct *sig)
2445 {
2446 	sig->cputimer.cputime = INIT_CPUTIME;
2447 	spin_lock_init(&sig->cputimer.lock);
2448 	sig->cputimer.running = 0;
2449 }
2450 
2451 static inline void thread_group_cputime_free(struct signal_struct *sig)
2452 {
2453 }
2454 
2455 /*
2456  * Reevaluate whether the task has signals pending delivery.
2457  * Wake the task if so.
2458  * This is required every time the blocked sigset_t changes.
2459  * callers must hold sighand->siglock.
2460  */
2461 extern void recalc_sigpending_and_wake(struct task_struct *t);
2462 extern void recalc_sigpending(void);
2463 
2464 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2465 
2466 /*
2467  * Wrappers for p->thread_info->cpu access. No-op on UP.
2468  */
2469 #ifdef CONFIG_SMP
2470 
2471 static inline unsigned int task_cpu(const struct task_struct *p)
2472 {
2473 	return task_thread_info(p)->cpu;
2474 }
2475 
2476 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2477 
2478 #else
2479 
2480 static inline unsigned int task_cpu(const struct task_struct *p)
2481 {
2482 	return 0;
2483 }
2484 
2485 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2486 {
2487 }
2488 
2489 #endif /* CONFIG_SMP */
2490 
2491 #ifdef CONFIG_TRACING
2492 extern void
2493 __trace_special(void *__tr, void *__data,
2494 		unsigned long arg1, unsigned long arg2, unsigned long arg3);
2495 #else
2496 static inline void
2497 __trace_special(void *__tr, void *__data,
2498 		unsigned long arg1, unsigned long arg2, unsigned long arg3)
2499 {
2500 }
2501 #endif
2502 
2503 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2504 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2505 
2506 extern void normalize_rt_tasks(void);
2507 
2508 #ifdef CONFIG_CGROUP_SCHED
2509 
2510 extern struct task_group init_task_group;
2511 
2512 extern struct task_group *sched_create_group(struct task_group *parent);
2513 extern void sched_destroy_group(struct task_group *tg);
2514 extern void sched_move_task(struct task_struct *tsk);
2515 #ifdef CONFIG_FAIR_GROUP_SCHED
2516 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2517 extern unsigned long sched_group_shares(struct task_group *tg);
2518 #endif
2519 #ifdef CONFIG_RT_GROUP_SCHED
2520 extern int sched_group_set_rt_runtime(struct task_group *tg,
2521 				      long rt_runtime_us);
2522 extern long sched_group_rt_runtime(struct task_group *tg);
2523 extern int sched_group_set_rt_period(struct task_group *tg,
2524 				      long rt_period_us);
2525 extern long sched_group_rt_period(struct task_group *tg);
2526 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2527 #endif
2528 #endif
2529 
2530 extern int task_can_switch_user(struct user_struct *up,
2531 					struct task_struct *tsk);
2532 
2533 #ifdef CONFIG_TASK_XACCT
2534 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2535 {
2536 	tsk->ioac.rchar += amt;
2537 }
2538 
2539 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2540 {
2541 	tsk->ioac.wchar += amt;
2542 }
2543 
2544 static inline void inc_syscr(struct task_struct *tsk)
2545 {
2546 	tsk->ioac.syscr++;
2547 }
2548 
2549 static inline void inc_syscw(struct task_struct *tsk)
2550 {
2551 	tsk->ioac.syscw++;
2552 }
2553 #else
2554 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2555 {
2556 }
2557 
2558 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2559 {
2560 }
2561 
2562 static inline void inc_syscr(struct task_struct *tsk)
2563 {
2564 }
2565 
2566 static inline void inc_syscw(struct task_struct *tsk)
2567 {
2568 }
2569 #endif
2570 
2571 #ifndef TASK_SIZE_OF
2572 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2573 #endif
2574 
2575 /*
2576  * Call the function if the target task is executing on a CPU right now:
2577  */
2578 extern void task_oncpu_function_call(struct task_struct *p,
2579 				     void (*func) (void *info), void *info);
2580 
2581 
2582 #ifdef CONFIG_MM_OWNER
2583 extern void mm_update_next_owner(struct mm_struct *mm);
2584 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2585 #else
2586 static inline void mm_update_next_owner(struct mm_struct *mm)
2587 {
2588 }
2589 
2590 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2591 {
2592 }
2593 #endif /* CONFIG_MM_OWNER */
2594 
2595 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2596 		unsigned int limit)
2597 {
2598 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2599 }
2600 
2601 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2602 		unsigned int limit)
2603 {
2604 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2605 }
2606 
2607 static inline unsigned long rlimit(unsigned int limit)
2608 {
2609 	return task_rlimit(current, limit);
2610 }
2611 
2612 static inline unsigned long rlimit_max(unsigned int limit)
2613 {
2614 	return task_rlimit_max(current, limit);
2615 }
2616 
2617 #endif /* __KERNEL__ */
2618 
2619 #endif
2620