xref: /linux/include/linux/sched.h (revision 42fda66387daa53538ae13a2c858396aaf037158)
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_NEWNET		0x40000000	/* New network namespace */
29 
30 /*
31  * Scheduling policies
32  */
33 #define SCHED_NORMAL		0
34 #define SCHED_FIFO		1
35 #define SCHED_RR		2
36 #define SCHED_BATCH		3
37 /* SCHED_ISO: reserved but not implemented yet */
38 #define SCHED_IDLE		5
39 
40 #ifdef __KERNEL__
41 
42 struct sched_param {
43 	int sched_priority;
44 };
45 
46 #include <asm/param.h>	/* for HZ */
47 
48 #include <linux/capability.h>
49 #include <linux/threads.h>
50 #include <linux/kernel.h>
51 #include <linux/types.h>
52 #include <linux/timex.h>
53 #include <linux/jiffies.h>
54 #include <linux/rbtree.h>
55 #include <linux/thread_info.h>
56 #include <linux/cpumask.h>
57 #include <linux/errno.h>
58 #include <linux/nodemask.h>
59 #include <linux/mm_types.h>
60 
61 #include <asm/system.h>
62 #include <asm/semaphore.h>
63 #include <asm/page.h>
64 #include <asm/ptrace.h>
65 #include <asm/cputime.h>
66 
67 #include <linux/smp.h>
68 #include <linux/sem.h>
69 #include <linux/signal.h>
70 #include <linux/securebits.h>
71 #include <linux/fs_struct.h>
72 #include <linux/compiler.h>
73 #include <linux/completion.h>
74 #include <linux/pid.h>
75 #include <linux/percpu.h>
76 #include <linux/topology.h>
77 #include <linux/seccomp.h>
78 #include <linux/rcupdate.h>
79 #include <linux/futex.h>
80 #include <linux/rtmutex.h>
81 
82 #include <linux/time.h>
83 #include <linux/param.h>
84 #include <linux/resource.h>
85 #include <linux/timer.h>
86 #include <linux/hrtimer.h>
87 #include <linux/task_io_accounting.h>
88 #include <linux/kobject.h>
89 
90 #include <asm/processor.h>
91 
92 struct exec_domain;
93 struct futex_pi_state;
94 struct bio;
95 
96 /*
97  * List of flags we want to share for kernel threads,
98  * if only because they are not used by them anyway.
99  */
100 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
101 
102 /*
103  * These are the constant used to fake the fixed-point load-average
104  * counting. Some notes:
105  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
106  *    a load-average precision of 10 bits integer + 11 bits fractional
107  *  - if you want to count load-averages more often, you need more
108  *    precision, or rounding will get you. With 2-second counting freq,
109  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
110  *    11 bit fractions.
111  */
112 extern unsigned long avenrun[];		/* Load averages */
113 
114 #define FSHIFT		11		/* nr of bits of precision */
115 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
116 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
117 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
118 #define EXP_5		2014		/* 1/exp(5sec/5min) */
119 #define EXP_15		2037		/* 1/exp(5sec/15min) */
120 
121 #define CALC_LOAD(load,exp,n) \
122 	load *= exp; \
123 	load += n*(FIXED_1-exp); \
124 	load >>= FSHIFT;
125 
126 extern unsigned long total_forks;
127 extern int nr_threads;
128 DECLARE_PER_CPU(unsigned long, process_counts);
129 extern int nr_processes(void);
130 extern unsigned long nr_running(void);
131 extern unsigned long nr_uninterruptible(void);
132 extern unsigned long nr_active(void);
133 extern unsigned long nr_iowait(void);
134 extern unsigned long weighted_cpuload(const int cpu);
135 
136 struct seq_file;
137 struct cfs_rq;
138 struct task_group;
139 #ifdef CONFIG_SCHED_DEBUG
140 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
141 extern void proc_sched_set_task(struct task_struct *p);
142 extern void
143 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
144 #else
145 static inline void
146 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
147 {
148 }
149 static inline void proc_sched_set_task(struct task_struct *p)
150 {
151 }
152 static inline void
153 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
154 {
155 }
156 #endif
157 
158 /*
159  * Task state bitmask. NOTE! These bits are also
160  * encoded in fs/proc/array.c: get_task_state().
161  *
162  * We have two separate sets of flags: task->state
163  * is about runnability, while task->exit_state are
164  * about the task exiting. Confusing, but this way
165  * modifying one set can't modify the other one by
166  * mistake.
167  */
168 #define TASK_RUNNING		0
169 #define TASK_INTERRUPTIBLE	1
170 #define TASK_UNINTERRUPTIBLE	2
171 #define TASK_STOPPED		4
172 #define TASK_TRACED		8
173 /* in tsk->exit_state */
174 #define EXIT_ZOMBIE		16
175 #define EXIT_DEAD		32
176 /* in tsk->state again */
177 #define TASK_DEAD		64
178 
179 #define __set_task_state(tsk, state_value)		\
180 	do { (tsk)->state = (state_value); } while (0)
181 #define set_task_state(tsk, state_value)		\
182 	set_mb((tsk)->state, (state_value))
183 
184 /*
185  * set_current_state() includes a barrier so that the write of current->state
186  * is correctly serialised wrt the caller's subsequent test of whether to
187  * actually sleep:
188  *
189  *	set_current_state(TASK_UNINTERRUPTIBLE);
190  *	if (do_i_need_to_sleep())
191  *		schedule();
192  *
193  * If the caller does not need such serialisation then use __set_current_state()
194  */
195 #define __set_current_state(state_value)			\
196 	do { current->state = (state_value); } while (0)
197 #define set_current_state(state_value)		\
198 	set_mb(current->state, (state_value))
199 
200 /* Task command name length */
201 #define TASK_COMM_LEN 16
202 
203 #include <linux/spinlock.h>
204 
205 /*
206  * This serializes "schedule()" and also protects
207  * the run-queue from deletions/modifications (but
208  * _adding_ to the beginning of the run-queue has
209  * a separate lock).
210  */
211 extern rwlock_t tasklist_lock;
212 extern spinlock_t mmlist_lock;
213 
214 struct task_struct;
215 
216 extern void sched_init(void);
217 extern void sched_init_smp(void);
218 extern void init_idle(struct task_struct *idle, int cpu);
219 extern void init_idle_bootup_task(struct task_struct *idle);
220 
221 extern cpumask_t nohz_cpu_mask;
222 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
223 extern int select_nohz_load_balancer(int cpu);
224 #else
225 static inline int select_nohz_load_balancer(int cpu)
226 {
227 	return 0;
228 }
229 #endif
230 
231 /*
232  * Only dump TASK_* tasks. (0 for all tasks)
233  */
234 extern void show_state_filter(unsigned long state_filter);
235 
236 static inline void show_state(void)
237 {
238 	show_state_filter(0);
239 }
240 
241 extern void show_regs(struct pt_regs *);
242 
243 /*
244  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
245  * task), SP is the stack pointer of the first frame that should be shown in the back
246  * trace (or NULL if the entire call-chain of the task should be shown).
247  */
248 extern void show_stack(struct task_struct *task, unsigned long *sp);
249 
250 void io_schedule(void);
251 long io_schedule_timeout(long timeout);
252 
253 extern void cpu_init (void);
254 extern void trap_init(void);
255 extern void update_process_times(int user);
256 extern void scheduler_tick(void);
257 
258 #ifdef CONFIG_DETECT_SOFTLOCKUP
259 extern void softlockup_tick(void);
260 extern void spawn_softlockup_task(void);
261 extern void touch_softlockup_watchdog(void);
262 extern void touch_all_softlockup_watchdogs(void);
263 #else
264 static inline void softlockup_tick(void)
265 {
266 }
267 static inline void spawn_softlockup_task(void)
268 {
269 }
270 static inline void touch_softlockup_watchdog(void)
271 {
272 }
273 static inline void touch_all_softlockup_watchdogs(void)
274 {
275 }
276 #endif
277 
278 
279 /* Attach to any functions which should be ignored in wchan output. */
280 #define __sched		__attribute__((__section__(".sched.text")))
281 /* Is this address in the __sched functions? */
282 extern int in_sched_functions(unsigned long addr);
283 
284 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
285 extern signed long FASTCALL(schedule_timeout(signed long timeout));
286 extern signed long schedule_timeout_interruptible(signed long timeout);
287 extern signed long schedule_timeout_uninterruptible(signed long timeout);
288 asmlinkage void schedule(void);
289 
290 struct nsproxy;
291 struct user_namespace;
292 
293 /* Maximum number of active map areas.. This is a random (large) number */
294 #define DEFAULT_MAX_MAP_COUNT	65536
295 
296 extern int sysctl_max_map_count;
297 
298 #include <linux/aio.h>
299 
300 extern unsigned long
301 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
302 		       unsigned long, unsigned long);
303 extern unsigned long
304 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
305 			  unsigned long len, unsigned long pgoff,
306 			  unsigned long flags);
307 extern void arch_unmap_area(struct mm_struct *, unsigned long);
308 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
309 
310 #if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
311 /*
312  * The mm counters are not protected by its page_table_lock,
313  * so must be incremented atomically.
314  */
315 #define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
316 #define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
317 #define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
318 #define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
319 #define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
320 
321 #else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
322 /*
323  * The mm counters are protected by its page_table_lock,
324  * so can be incremented directly.
325  */
326 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
327 #define get_mm_counter(mm, member) ((mm)->_##member)
328 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
329 #define inc_mm_counter(mm, member) (mm)->_##member++
330 #define dec_mm_counter(mm, member) (mm)->_##member--
331 
332 #endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
333 
334 #define get_mm_rss(mm)					\
335 	(get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
336 #define update_hiwater_rss(mm)	do {			\
337 	unsigned long _rss = get_mm_rss(mm);		\
338 	if ((mm)->hiwater_rss < _rss)			\
339 		(mm)->hiwater_rss = _rss;		\
340 } while (0)
341 #define update_hiwater_vm(mm)	do {			\
342 	if ((mm)->hiwater_vm < (mm)->total_vm)		\
343 		(mm)->hiwater_vm = (mm)->total_vm;	\
344 } while (0)
345 
346 extern void set_dumpable(struct mm_struct *mm, int value);
347 extern int get_dumpable(struct mm_struct *mm);
348 
349 /* mm flags */
350 /* dumpable bits */
351 #define MMF_DUMPABLE      0  /* core dump is permitted */
352 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
353 #define MMF_DUMPABLE_BITS 2
354 
355 /* coredump filter bits */
356 #define MMF_DUMP_ANON_PRIVATE	2
357 #define MMF_DUMP_ANON_SHARED	3
358 #define MMF_DUMP_MAPPED_PRIVATE	4
359 #define MMF_DUMP_MAPPED_SHARED	5
360 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
361 #define MMF_DUMP_FILTER_BITS	4
362 #define MMF_DUMP_FILTER_MASK \
363 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
364 #define MMF_DUMP_FILTER_DEFAULT \
365 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED))
366 
367 struct sighand_struct {
368 	atomic_t		count;
369 	struct k_sigaction	action[_NSIG];
370 	spinlock_t		siglock;
371 	wait_queue_head_t	signalfd_wqh;
372 };
373 
374 struct pacct_struct {
375 	int			ac_flag;
376 	long			ac_exitcode;
377 	unsigned long		ac_mem;
378 	cputime_t		ac_utime, ac_stime;
379 	unsigned long		ac_minflt, ac_majflt;
380 };
381 
382 /*
383  * NOTE! "signal_struct" does not have it's own
384  * locking, because a shared signal_struct always
385  * implies a shared sighand_struct, so locking
386  * sighand_struct is always a proper superset of
387  * the locking of signal_struct.
388  */
389 struct signal_struct {
390 	atomic_t		count;
391 	atomic_t		live;
392 
393 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
394 
395 	/* current thread group signal load-balancing target: */
396 	struct task_struct	*curr_target;
397 
398 	/* shared signal handling: */
399 	struct sigpending	shared_pending;
400 
401 	/* thread group exit support */
402 	int			group_exit_code;
403 	/* overloaded:
404 	 * - notify group_exit_task when ->count is equal to notify_count
405 	 * - everyone except group_exit_task is stopped during signal delivery
406 	 *   of fatal signals, group_exit_task processes the signal.
407 	 */
408 	struct task_struct	*group_exit_task;
409 	int			notify_count;
410 
411 	/* thread group stop support, overloads group_exit_code too */
412 	int			group_stop_count;
413 	unsigned int		flags; /* see SIGNAL_* flags below */
414 
415 	/* POSIX.1b Interval Timers */
416 	struct list_head posix_timers;
417 
418 	/* ITIMER_REAL timer for the process */
419 	struct hrtimer real_timer;
420 	struct task_struct *tsk;
421 	ktime_t it_real_incr;
422 
423 	/* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
424 	cputime_t it_prof_expires, it_virt_expires;
425 	cputime_t it_prof_incr, it_virt_incr;
426 
427 	/* job control IDs */
428 	pid_t pgrp;
429 	struct pid *tty_old_pgrp;
430 
431 	union {
432 		pid_t session __deprecated;
433 		pid_t __session;
434 	};
435 
436 	/* boolean value for session group leader */
437 	int leader;
438 
439 	struct tty_struct *tty; /* NULL if no tty */
440 
441 	/*
442 	 * Cumulative resource counters for dead threads in the group,
443 	 * and for reaped dead child processes forked by this group.
444 	 * Live threads maintain their own counters and add to these
445 	 * in __exit_signal, except for the group leader.
446 	 */
447 	cputime_t utime, stime, cutime, cstime;
448 	cputime_t gtime;
449 	cputime_t cgtime;
450 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
451 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
452 	unsigned long inblock, oublock, cinblock, coublock;
453 
454 	/*
455 	 * Cumulative ns of scheduled CPU time for dead threads in the
456 	 * group, not including a zombie group leader.  (This only differs
457 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
458 	 * other than jiffies.)
459 	 */
460 	unsigned long long sum_sched_runtime;
461 
462 	/*
463 	 * We don't bother to synchronize most readers of this at all,
464 	 * because there is no reader checking a limit that actually needs
465 	 * to get both rlim_cur and rlim_max atomically, and either one
466 	 * alone is a single word that can safely be read normally.
467 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
468 	 * protect this instead of the siglock, because they really
469 	 * have no need to disable irqs.
470 	 */
471 	struct rlimit rlim[RLIM_NLIMITS];
472 
473 	struct list_head cpu_timers[3];
474 
475 	/* keep the process-shared keyrings here so that they do the right
476 	 * thing in threads created with CLONE_THREAD */
477 #ifdef CONFIG_KEYS
478 	struct key *session_keyring;	/* keyring inherited over fork */
479 	struct key *process_keyring;	/* keyring private to this process */
480 #endif
481 #ifdef CONFIG_BSD_PROCESS_ACCT
482 	struct pacct_struct pacct;	/* per-process accounting information */
483 #endif
484 #ifdef CONFIG_TASKSTATS
485 	struct taskstats *stats;
486 #endif
487 #ifdef CONFIG_AUDIT
488 	unsigned audit_tty;
489 	struct tty_audit_buf *tty_audit_buf;
490 #endif
491 };
492 
493 /* Context switch must be unlocked if interrupts are to be enabled */
494 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
495 # define __ARCH_WANT_UNLOCKED_CTXSW
496 #endif
497 
498 /*
499  * Bits in flags field of signal_struct.
500  */
501 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
502 #define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
503 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
504 #define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
505 
506 /*
507  * Some day this will be a full-fledged user tracking system..
508  */
509 struct user_struct {
510 	atomic_t __count;	/* reference count */
511 	atomic_t processes;	/* How many processes does this user have? */
512 	atomic_t files;		/* How many open files does this user have? */
513 	atomic_t sigpending;	/* How many pending signals does this user have? */
514 #ifdef CONFIG_INOTIFY_USER
515 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
516 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
517 #endif
518 	/* protected by mq_lock	*/
519 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
520 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
521 
522 #ifdef CONFIG_KEYS
523 	struct key *uid_keyring;	/* UID specific keyring */
524 	struct key *session_keyring;	/* UID's default session keyring */
525 #endif
526 
527 	/* Hash table maintenance information */
528 	struct hlist_node uidhash_node;
529 	uid_t uid;
530 
531 #ifdef CONFIG_FAIR_USER_SCHED
532 	struct task_group *tg;
533 	struct kset kset;
534 	struct subsys_attribute user_attr;
535 	struct work_struct work;
536 #endif
537 };
538 
539 #ifdef CONFIG_FAIR_USER_SCHED
540 extern int uids_kobject_init(void);
541 #else
542 static inline int uids_kobject_init(void) { return 0; }
543 #endif
544 
545 extern struct user_struct *find_user(uid_t);
546 
547 extern struct user_struct root_user;
548 #define INIT_USER (&root_user)
549 
550 struct backing_dev_info;
551 struct reclaim_state;
552 
553 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
554 struct sched_info {
555 	/* cumulative counters */
556 	unsigned long pcount;	      /* # of times run on this cpu */
557 	unsigned long long cpu_time,  /* time spent on the cpu */
558 			   run_delay; /* time spent waiting on a runqueue */
559 
560 	/* timestamps */
561 	unsigned long long last_arrival,/* when we last ran on a cpu */
562 			   last_queued;	/* when we were last queued to run */
563 #ifdef CONFIG_SCHEDSTATS
564 	/* BKL stats */
565 	unsigned long bkl_count;
566 #endif
567 };
568 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
569 
570 #ifdef CONFIG_SCHEDSTATS
571 extern const struct file_operations proc_schedstat_operations;
572 #endif /* CONFIG_SCHEDSTATS */
573 
574 #ifdef CONFIG_TASK_DELAY_ACCT
575 struct task_delay_info {
576 	spinlock_t	lock;
577 	unsigned int	flags;	/* Private per-task flags */
578 
579 	/* For each stat XXX, add following, aligned appropriately
580 	 *
581 	 * struct timespec XXX_start, XXX_end;
582 	 * u64 XXX_delay;
583 	 * u32 XXX_count;
584 	 *
585 	 * Atomicity of updates to XXX_delay, XXX_count protected by
586 	 * single lock above (split into XXX_lock if contention is an issue).
587 	 */
588 
589 	/*
590 	 * XXX_count is incremented on every XXX operation, the delay
591 	 * associated with the operation is added to XXX_delay.
592 	 * XXX_delay contains the accumulated delay time in nanoseconds.
593 	 */
594 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
595 	u64 blkio_delay;	/* wait for sync block io completion */
596 	u64 swapin_delay;	/* wait for swapin block io completion */
597 	u32 blkio_count;	/* total count of the number of sync block */
598 				/* io operations performed */
599 	u32 swapin_count;	/* total count of the number of swapin block */
600 				/* io operations performed */
601 };
602 #endif	/* CONFIG_TASK_DELAY_ACCT */
603 
604 static inline int sched_info_on(void)
605 {
606 #ifdef CONFIG_SCHEDSTATS
607 	return 1;
608 #elif defined(CONFIG_TASK_DELAY_ACCT)
609 	extern int delayacct_on;
610 	return delayacct_on;
611 #else
612 	return 0;
613 #endif
614 }
615 
616 enum cpu_idle_type {
617 	CPU_IDLE,
618 	CPU_NOT_IDLE,
619 	CPU_NEWLY_IDLE,
620 	CPU_MAX_IDLE_TYPES
621 };
622 
623 /*
624  * sched-domains (multiprocessor balancing) declarations:
625  */
626 
627 /*
628  * Increase resolution of nice-level calculations:
629  */
630 #define SCHED_LOAD_SHIFT	10
631 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
632 
633 #define SCHED_LOAD_SCALE_FUZZ	SCHED_LOAD_SCALE
634 
635 #ifdef CONFIG_SMP
636 #define SD_LOAD_BALANCE		1	/* Do load balancing on this domain. */
637 #define SD_BALANCE_NEWIDLE	2	/* Balance when about to become idle */
638 #define SD_BALANCE_EXEC		4	/* Balance on exec */
639 #define SD_BALANCE_FORK		8	/* Balance on fork, clone */
640 #define SD_WAKE_IDLE		16	/* Wake to idle CPU on task wakeup */
641 #define SD_WAKE_AFFINE		32	/* Wake task to waking CPU */
642 #define SD_WAKE_BALANCE		64	/* Perform balancing at task wakeup */
643 #define SD_SHARE_CPUPOWER	128	/* Domain members share cpu power */
644 #define SD_POWERSAVINGS_BALANCE	256	/* Balance for power savings */
645 #define SD_SHARE_PKG_RESOURCES	512	/* Domain members share cpu pkg resources */
646 #define SD_SERIALIZE		1024	/* Only a single load balancing instance */
647 
648 #define BALANCE_FOR_MC_POWER	\
649 	(sched_smt_power_savings ? SD_POWERSAVINGS_BALANCE : 0)
650 
651 #define BALANCE_FOR_PKG_POWER	\
652 	((sched_mc_power_savings || sched_smt_power_savings) ?	\
653 	 SD_POWERSAVINGS_BALANCE : 0)
654 
655 #define test_sd_parent(sd, flag)	((sd->parent &&		\
656 					 (sd->parent->flags & flag)) ? 1 : 0)
657 
658 
659 struct sched_group {
660 	struct sched_group *next;	/* Must be a circular list */
661 	cpumask_t cpumask;
662 
663 	/*
664 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
665 	 * single CPU. This is read only (except for setup, hotplug CPU).
666 	 * Note : Never change cpu_power without recompute its reciprocal
667 	 */
668 	unsigned int __cpu_power;
669 	/*
670 	 * reciprocal value of cpu_power to avoid expensive divides
671 	 * (see include/linux/reciprocal_div.h)
672 	 */
673 	u32 reciprocal_cpu_power;
674 };
675 
676 struct sched_domain {
677 	/* These fields must be setup */
678 	struct sched_domain *parent;	/* top domain must be null terminated */
679 	struct sched_domain *child;	/* bottom domain must be null terminated */
680 	struct sched_group *groups;	/* the balancing groups of the domain */
681 	cpumask_t span;			/* span of all CPUs in this domain */
682 	unsigned long min_interval;	/* Minimum balance interval ms */
683 	unsigned long max_interval;	/* Maximum balance interval ms */
684 	unsigned int busy_factor;	/* less balancing by factor if busy */
685 	unsigned int imbalance_pct;	/* No balance until over watermark */
686 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
687 	unsigned int busy_idx;
688 	unsigned int idle_idx;
689 	unsigned int newidle_idx;
690 	unsigned int wake_idx;
691 	unsigned int forkexec_idx;
692 	int flags;			/* See SD_* */
693 
694 	/* Runtime fields. */
695 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
696 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
697 	unsigned int nr_balance_failed; /* initialise to 0 */
698 
699 #ifdef CONFIG_SCHEDSTATS
700 	/* load_balance() stats */
701 	unsigned long lb_count[CPU_MAX_IDLE_TYPES];
702 	unsigned long lb_failed[CPU_MAX_IDLE_TYPES];
703 	unsigned long lb_balanced[CPU_MAX_IDLE_TYPES];
704 	unsigned long lb_imbalance[CPU_MAX_IDLE_TYPES];
705 	unsigned long lb_gained[CPU_MAX_IDLE_TYPES];
706 	unsigned long lb_hot_gained[CPU_MAX_IDLE_TYPES];
707 	unsigned long lb_nobusyg[CPU_MAX_IDLE_TYPES];
708 	unsigned long lb_nobusyq[CPU_MAX_IDLE_TYPES];
709 
710 	/* Active load balancing */
711 	unsigned long alb_count;
712 	unsigned long alb_failed;
713 	unsigned long alb_pushed;
714 
715 	/* SD_BALANCE_EXEC stats */
716 	unsigned long sbe_count;
717 	unsigned long sbe_balanced;
718 	unsigned long sbe_pushed;
719 
720 	/* SD_BALANCE_FORK stats */
721 	unsigned long sbf_count;
722 	unsigned long sbf_balanced;
723 	unsigned long sbf_pushed;
724 
725 	/* try_to_wake_up() stats */
726 	unsigned long ttwu_wake_remote;
727 	unsigned long ttwu_move_affine;
728 	unsigned long ttwu_move_balance;
729 #endif
730 };
731 
732 extern int partition_sched_domains(cpumask_t *partition1,
733 				    cpumask_t *partition2);
734 
735 #endif	/* CONFIG_SMP */
736 
737 /*
738  * A runqueue laden with a single nice 0 task scores a weighted_cpuload of
739  * SCHED_LOAD_SCALE. This function returns 1 if any cpu is laden with a
740  * task of nice 0 or enough lower priority tasks to bring up the
741  * weighted_cpuload
742  */
743 static inline int above_background_load(void)
744 {
745 	unsigned long cpu;
746 
747 	for_each_online_cpu(cpu) {
748 		if (weighted_cpuload(cpu) >= SCHED_LOAD_SCALE)
749 			return 1;
750 	}
751 	return 0;
752 }
753 
754 struct io_context;			/* See blkdev.h */
755 struct cpuset;
756 
757 #define NGROUPS_SMALL		32
758 #define NGROUPS_PER_BLOCK	((int)(PAGE_SIZE / sizeof(gid_t)))
759 struct group_info {
760 	int ngroups;
761 	atomic_t usage;
762 	gid_t small_block[NGROUPS_SMALL];
763 	int nblocks;
764 	gid_t *blocks[0];
765 };
766 
767 /*
768  * get_group_info() must be called with the owning task locked (via task_lock())
769  * when task != current.  The reason being that the vast majority of callers are
770  * looking at current->group_info, which can not be changed except by the
771  * current task.  Changing current->group_info requires the task lock, too.
772  */
773 #define get_group_info(group_info) do { \
774 	atomic_inc(&(group_info)->usage); \
775 } while (0)
776 
777 #define put_group_info(group_info) do { \
778 	if (atomic_dec_and_test(&(group_info)->usage)) \
779 		groups_free(group_info); \
780 } while (0)
781 
782 extern struct group_info *groups_alloc(int gidsetsize);
783 extern void groups_free(struct group_info *group_info);
784 extern int set_current_groups(struct group_info *group_info);
785 extern int groups_search(struct group_info *group_info, gid_t grp);
786 /* access the groups "array" with this macro */
787 #define GROUP_AT(gi, i) \
788     ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK])
789 
790 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
791 extern void prefetch_stack(struct task_struct *t);
792 #else
793 static inline void prefetch_stack(struct task_struct *t) { }
794 #endif
795 
796 struct audit_context;		/* See audit.c */
797 struct mempolicy;
798 struct pipe_inode_info;
799 struct uts_namespace;
800 
801 struct rq;
802 struct sched_domain;
803 
804 struct sched_class {
805 	const struct sched_class *next;
806 
807 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
808 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
809 	void (*yield_task) (struct rq *rq);
810 
811 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p);
812 
813 	struct task_struct * (*pick_next_task) (struct rq *rq);
814 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
815 
816 	unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
817 			struct rq *busiest,
818 			unsigned long max_nr_move, unsigned long max_load_move,
819 			struct sched_domain *sd, enum cpu_idle_type idle,
820 			int *all_pinned, int *this_best_prio);
821 
822 	void (*set_curr_task) (struct rq *rq);
823 	void (*task_tick) (struct rq *rq, struct task_struct *p);
824 	void (*task_new) (struct rq *rq, struct task_struct *p);
825 };
826 
827 struct load_weight {
828 	unsigned long weight, inv_weight;
829 };
830 
831 /*
832  * CFS stats for a schedulable entity (task, task-group etc)
833  *
834  * Current field usage histogram:
835  *
836  *     4 se->block_start
837  *     4 se->run_node
838  *     4 se->sleep_start
839  *     6 se->load.weight
840  */
841 struct sched_entity {
842 	struct load_weight	load;		/* for load-balancing */
843 	struct rb_node		run_node;
844 	unsigned int		on_rq;
845 	int			peer_preempt;
846 
847 	u64			exec_start;
848 	u64			sum_exec_runtime;
849 	u64			vruntime;
850 	u64			prev_sum_exec_runtime;
851 
852 #ifdef CONFIG_SCHEDSTATS
853 	u64			wait_start;
854 	u64			wait_max;
855 
856 	u64			sleep_start;
857 	u64			sleep_max;
858 	s64			sum_sleep_runtime;
859 
860 	u64			block_start;
861 	u64			block_max;
862 	u64			exec_max;
863 	u64			slice_max;
864 
865 	u64			nr_migrations;
866 	u64			nr_migrations_cold;
867 	u64			nr_failed_migrations_affine;
868 	u64			nr_failed_migrations_running;
869 	u64			nr_failed_migrations_hot;
870 	u64			nr_forced_migrations;
871 	u64			nr_forced2_migrations;
872 
873 	u64			nr_wakeups;
874 	u64			nr_wakeups_sync;
875 	u64			nr_wakeups_migrate;
876 	u64			nr_wakeups_local;
877 	u64			nr_wakeups_remote;
878 	u64			nr_wakeups_affine;
879 	u64			nr_wakeups_affine_attempts;
880 	u64			nr_wakeups_passive;
881 	u64			nr_wakeups_idle;
882 #endif
883 
884 #ifdef CONFIG_FAIR_GROUP_SCHED
885 	struct sched_entity	*parent;
886 	/* rq on which this entity is (to be) queued: */
887 	struct cfs_rq		*cfs_rq;
888 	/* rq "owned" by this entity/group: */
889 	struct cfs_rq		*my_q;
890 #endif
891 };
892 
893 struct task_struct {
894 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
895 	void *stack;
896 	atomic_t usage;
897 	unsigned int flags;	/* per process flags, defined below */
898 	unsigned int ptrace;
899 
900 	int lock_depth;		/* BKL lock depth */
901 
902 #ifdef CONFIG_SMP
903 #ifdef __ARCH_WANT_UNLOCKED_CTXSW
904 	int oncpu;
905 #endif
906 #endif
907 
908 	int prio, static_prio, normal_prio;
909 	struct list_head run_list;
910 	const struct sched_class *sched_class;
911 	struct sched_entity se;
912 
913 #ifdef CONFIG_PREEMPT_NOTIFIERS
914 	/* list of struct preempt_notifier: */
915 	struct hlist_head preempt_notifiers;
916 #endif
917 
918 	unsigned short ioprio;
919 #ifdef CONFIG_BLK_DEV_IO_TRACE
920 	unsigned int btrace_seq;
921 #endif
922 
923 	unsigned int policy;
924 	cpumask_t cpus_allowed;
925 	unsigned int time_slice;
926 
927 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
928 	struct sched_info sched_info;
929 #endif
930 
931 	struct list_head tasks;
932 	/*
933 	 * ptrace_list/ptrace_children forms the list of my children
934 	 * that were stolen by a ptracer.
935 	 */
936 	struct list_head ptrace_children;
937 	struct list_head ptrace_list;
938 
939 	struct mm_struct *mm, *active_mm;
940 
941 /* task state */
942 	struct linux_binfmt *binfmt;
943 	int exit_state;
944 	int exit_code, exit_signal;
945 	int pdeath_signal;  /*  The signal sent when the parent dies  */
946 	/* ??? */
947 	unsigned int personality;
948 	unsigned did_exec:1;
949 	pid_t pid;
950 	pid_t tgid;
951 
952 #ifdef CONFIG_CC_STACKPROTECTOR
953 	/* Canary value for the -fstack-protector gcc feature */
954 	unsigned long stack_canary;
955 #endif
956 	/*
957 	 * pointers to (original) parent process, youngest child, younger sibling,
958 	 * older sibling, respectively.  (p->father can be replaced with
959 	 * p->parent->pid)
960 	 */
961 	struct task_struct *real_parent; /* real parent process (when being debugged) */
962 	struct task_struct *parent;	/* parent process */
963 	/*
964 	 * children/sibling forms the list of my children plus the
965 	 * tasks I'm ptracing.
966 	 */
967 	struct list_head children;	/* list of my children */
968 	struct list_head sibling;	/* linkage in my parent's children list */
969 	struct task_struct *group_leader;	/* threadgroup leader */
970 
971 	/* PID/PID hash table linkage. */
972 	struct pid_link pids[PIDTYPE_MAX];
973 	struct list_head thread_group;
974 
975 	struct completion *vfork_done;		/* for vfork() */
976 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
977 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
978 
979 	unsigned int rt_priority;
980 	cputime_t utime, stime;
981 	cputime_t gtime;
982 	unsigned long nvcsw, nivcsw; /* context switch counts */
983 	struct timespec start_time; 		/* monotonic time */
984 	struct timespec real_start_time;	/* boot based time */
985 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
986 	unsigned long min_flt, maj_flt;
987 
988   	cputime_t it_prof_expires, it_virt_expires;
989 	unsigned long long it_sched_expires;
990 	struct list_head cpu_timers[3];
991 
992 /* process credentials */
993 	uid_t uid,euid,suid,fsuid;
994 	gid_t gid,egid,sgid,fsgid;
995 	struct group_info *group_info;
996 	kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
997 	unsigned keep_capabilities:1;
998 	struct user_struct *user;
999 #ifdef CONFIG_KEYS
1000 	struct key *request_key_auth;	/* assumed request_key authority */
1001 	struct key *thread_keyring;	/* keyring private to this thread */
1002 	unsigned char jit_keyring;	/* default keyring to attach requested keys to */
1003 #endif
1004 	/*
1005 	 * fpu_counter contains the number of consecutive context switches
1006 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1007 	 * saving becomes unlazy to save the trap. This is an unsigned char
1008 	 * so that after 256 times the counter wraps and the behavior turns
1009 	 * lazy again; this to deal with bursty apps that only use FPU for
1010 	 * a short time
1011 	 */
1012 	unsigned char fpu_counter;
1013 	int oomkilladj; /* OOM kill score adjustment (bit shift). */
1014 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1015 				     - access with [gs]et_task_comm (which lock
1016 				       it with task_lock())
1017 				     - initialized normally by flush_old_exec */
1018 /* file system info */
1019 	int link_count, total_link_count;
1020 #ifdef CONFIG_SYSVIPC
1021 /* ipc stuff */
1022 	struct sysv_sem sysvsem;
1023 #endif
1024 /* CPU-specific state of this task */
1025 	struct thread_struct thread;
1026 /* filesystem information */
1027 	struct fs_struct *fs;
1028 /* open file information */
1029 	struct files_struct *files;
1030 /* namespaces */
1031 	struct nsproxy *nsproxy;
1032 /* signal handlers */
1033 	struct signal_struct *signal;
1034 	struct sighand_struct *sighand;
1035 
1036 	sigset_t blocked, real_blocked;
1037 	sigset_t saved_sigmask;		/* To be restored with TIF_RESTORE_SIGMASK */
1038 	struct sigpending pending;
1039 
1040 	unsigned long sas_ss_sp;
1041 	size_t sas_ss_size;
1042 	int (*notifier)(void *priv);
1043 	void *notifier_data;
1044 	sigset_t *notifier_mask;
1045 
1046 	void *security;
1047 	struct audit_context *audit_context;
1048 	seccomp_t seccomp;
1049 
1050 /* Thread group tracking */
1051    	u32 parent_exec_id;
1052    	u32 self_exec_id;
1053 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
1054 	spinlock_t alloc_lock;
1055 
1056 	/* Protection of the PI data structures: */
1057 	spinlock_t pi_lock;
1058 
1059 #ifdef CONFIG_RT_MUTEXES
1060 	/* PI waiters blocked on a rt_mutex held by this task */
1061 	struct plist_head pi_waiters;
1062 	/* Deadlock detection and priority inheritance handling */
1063 	struct rt_mutex_waiter *pi_blocked_on;
1064 #endif
1065 
1066 #ifdef CONFIG_DEBUG_MUTEXES
1067 	/* mutex deadlock detection */
1068 	struct mutex_waiter *blocked_on;
1069 #endif
1070 #ifdef CONFIG_TRACE_IRQFLAGS
1071 	unsigned int irq_events;
1072 	int hardirqs_enabled;
1073 	unsigned long hardirq_enable_ip;
1074 	unsigned int hardirq_enable_event;
1075 	unsigned long hardirq_disable_ip;
1076 	unsigned int hardirq_disable_event;
1077 	int softirqs_enabled;
1078 	unsigned long softirq_disable_ip;
1079 	unsigned int softirq_disable_event;
1080 	unsigned long softirq_enable_ip;
1081 	unsigned int softirq_enable_event;
1082 	int hardirq_context;
1083 	int softirq_context;
1084 #endif
1085 #ifdef CONFIG_LOCKDEP
1086 # define MAX_LOCK_DEPTH 30UL
1087 	u64 curr_chain_key;
1088 	int lockdep_depth;
1089 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1090 	unsigned int lockdep_recursion;
1091 #endif
1092 
1093 /* journalling filesystem info */
1094 	void *journal_info;
1095 
1096 /* stacked block device info */
1097 	struct bio *bio_list, **bio_tail;
1098 
1099 /* VM state */
1100 	struct reclaim_state *reclaim_state;
1101 
1102 	struct backing_dev_info *backing_dev_info;
1103 
1104 	struct io_context *io_context;
1105 
1106 	unsigned long ptrace_message;
1107 	siginfo_t *last_siginfo; /* For ptrace use.  */
1108 /*
1109  * current io wait handle: wait queue entry to use for io waits
1110  * If this thread is processing aio, this points at the waitqueue
1111  * inside the currently handled kiocb. It may be NULL (i.e. default
1112  * to a stack based synchronous wait) if its doing sync IO.
1113  */
1114 	wait_queue_t *io_wait;
1115 #ifdef CONFIG_TASK_XACCT
1116 /* i/o counters(bytes read/written, #syscalls */
1117 	u64 rchar, wchar, syscr, syscw;
1118 #endif
1119 	struct task_io_accounting ioac;
1120 #if defined(CONFIG_TASK_XACCT)
1121 	u64 acct_rss_mem1;	/* accumulated rss usage */
1122 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1123 	cputime_t acct_stimexpd;/* stime since last update */
1124 #endif
1125 #ifdef CONFIG_NUMA
1126   	struct mempolicy *mempolicy;
1127 	short il_next;
1128 #endif
1129 #ifdef CONFIG_CPUSETS
1130 	struct cpuset *cpuset;
1131 	nodemask_t mems_allowed;
1132 	int cpuset_mems_generation;
1133 	int cpuset_mem_spread_rotor;
1134 #endif
1135 	struct robust_list_head __user *robust_list;
1136 #ifdef CONFIG_COMPAT
1137 	struct compat_robust_list_head __user *compat_robust_list;
1138 #endif
1139 	struct list_head pi_state_list;
1140 	struct futex_pi_state *pi_state_cache;
1141 
1142 	atomic_t fs_excl;	/* holding fs exclusive resources */
1143 	struct rcu_head rcu;
1144 
1145 	/*
1146 	 * cache last used pipe for splice
1147 	 */
1148 	struct pipe_inode_info *splice_pipe;
1149 #ifdef	CONFIG_TASK_DELAY_ACCT
1150 	struct task_delay_info *delays;
1151 #endif
1152 #ifdef CONFIG_FAULT_INJECTION
1153 	int make_it_fail;
1154 #endif
1155 };
1156 
1157 /*
1158  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1159  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1160  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1161  * values are inverted: lower p->prio value means higher priority.
1162  *
1163  * The MAX_USER_RT_PRIO value allows the actual maximum
1164  * RT priority to be separate from the value exported to
1165  * user-space.  This allows kernel threads to set their
1166  * priority to a value higher than any user task. Note:
1167  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1168  */
1169 
1170 #define MAX_USER_RT_PRIO	100
1171 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1172 
1173 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1174 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1175 
1176 static inline int rt_prio(int prio)
1177 {
1178 	if (unlikely(prio < MAX_RT_PRIO))
1179 		return 1;
1180 	return 0;
1181 }
1182 
1183 static inline int rt_task(struct task_struct *p)
1184 {
1185 	return rt_prio(p->prio);
1186 }
1187 
1188 static inline pid_t process_group(struct task_struct *tsk)
1189 {
1190 	return tsk->signal->pgrp;
1191 }
1192 
1193 static inline pid_t signal_session(struct signal_struct *sig)
1194 {
1195 	return sig->__session;
1196 }
1197 
1198 static inline pid_t process_session(struct task_struct *tsk)
1199 {
1200 	return signal_session(tsk->signal);
1201 }
1202 
1203 static inline void set_signal_session(struct signal_struct *sig, pid_t session)
1204 {
1205 	sig->__session = session;
1206 }
1207 
1208 static inline struct pid *task_pid(struct task_struct *task)
1209 {
1210 	return task->pids[PIDTYPE_PID].pid;
1211 }
1212 
1213 static inline struct pid *task_tgid(struct task_struct *task)
1214 {
1215 	return task->group_leader->pids[PIDTYPE_PID].pid;
1216 }
1217 
1218 static inline struct pid *task_pgrp(struct task_struct *task)
1219 {
1220 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1221 }
1222 
1223 static inline struct pid *task_session(struct task_struct *task)
1224 {
1225 	return task->group_leader->pids[PIDTYPE_SID].pid;
1226 }
1227 
1228 /**
1229  * pid_alive - check that a task structure is not stale
1230  * @p: Task structure to be checked.
1231  *
1232  * Test if a process is not yet dead (at most zombie state)
1233  * If pid_alive fails, then pointers within the task structure
1234  * can be stale and must not be dereferenced.
1235  */
1236 static inline int pid_alive(struct task_struct *p)
1237 {
1238 	return p->pids[PIDTYPE_PID].pid != NULL;
1239 }
1240 
1241 /**
1242  * is_init - check if a task structure is init
1243  * @tsk: Task structure to be checked.
1244  *
1245  * Check if a task structure is the first user space task the kernel created.
1246  */
1247 static inline int is_init(struct task_struct *tsk)
1248 {
1249 	return tsk->pid == 1;
1250 }
1251 
1252 extern struct pid *cad_pid;
1253 
1254 extern void free_task(struct task_struct *tsk);
1255 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1256 
1257 extern void __put_task_struct(struct task_struct *t);
1258 
1259 static inline void put_task_struct(struct task_struct *t)
1260 {
1261 	if (atomic_dec_and_test(&t->usage))
1262 		__put_task_struct(t);
1263 }
1264 
1265 /*
1266  * Per process flags
1267  */
1268 #define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
1269 					/* Not implemented yet, only for 486*/
1270 #define PF_STARTING	0x00000002	/* being created */
1271 #define PF_EXITING	0x00000004	/* getting shut down */
1272 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1273 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1274 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1275 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1276 #define PF_DUMPCORE	0x00000200	/* dumped core */
1277 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1278 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1279 #define PF_FLUSHER	0x00001000	/* responsible for disk writeback */
1280 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1281 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1282 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1283 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1284 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1285 #define PF_SWAPOFF	0x00080000	/* I am in swapoff */
1286 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1287 #define PF_BORROWED_MM	0x00200000	/* I am a kthread doing use_mm */
1288 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1289 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1290 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1291 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1292 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1293 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1294 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezeable */
1295 
1296 /*
1297  * Only the _current_ task can read/write to tsk->flags, but other
1298  * tasks can access tsk->flags in readonly mode for example
1299  * with tsk_used_math (like during threaded core dumping).
1300  * There is however an exception to this rule during ptrace
1301  * or during fork: the ptracer task is allowed to write to the
1302  * child->flags of its traced child (same goes for fork, the parent
1303  * can write to the child->flags), because we're guaranteed the
1304  * child is not running and in turn not changing child->flags
1305  * at the same time the parent does it.
1306  */
1307 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1308 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1309 #define clear_used_math() clear_stopped_child_used_math(current)
1310 #define set_used_math() set_stopped_child_used_math(current)
1311 #define conditional_stopped_child_used_math(condition, child) \
1312 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1313 #define conditional_used_math(condition) \
1314 	conditional_stopped_child_used_math(condition, current)
1315 #define copy_to_stopped_child_used_math(child) \
1316 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1317 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1318 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1319 #define used_math() tsk_used_math(current)
1320 
1321 #ifdef CONFIG_SMP
1322 extern int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask);
1323 #else
1324 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1325 {
1326 	if (!cpu_isset(0, new_mask))
1327 		return -EINVAL;
1328 	return 0;
1329 }
1330 #endif
1331 
1332 extern unsigned long long sched_clock(void);
1333 
1334 /*
1335  * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
1336  * clock constructed from sched_clock():
1337  */
1338 extern unsigned long long cpu_clock(int cpu);
1339 
1340 extern unsigned long long
1341 task_sched_runtime(struct task_struct *task);
1342 
1343 /* sched_exec is called by processes performing an exec */
1344 #ifdef CONFIG_SMP
1345 extern void sched_exec(void);
1346 #else
1347 #define sched_exec()   {}
1348 #endif
1349 
1350 extern void sched_clock_idle_sleep_event(void);
1351 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1352 
1353 #ifdef CONFIG_HOTPLUG_CPU
1354 extern void idle_task_exit(void);
1355 #else
1356 static inline void idle_task_exit(void) {}
1357 #endif
1358 
1359 extern void sched_idle_next(void);
1360 
1361 #ifdef CONFIG_SCHED_DEBUG
1362 extern unsigned int sysctl_sched_latency;
1363 extern unsigned int sysctl_sched_nr_latency;
1364 extern unsigned int sysctl_sched_wakeup_granularity;
1365 extern unsigned int sysctl_sched_batch_wakeup_granularity;
1366 extern unsigned int sysctl_sched_child_runs_first;
1367 extern unsigned int sysctl_sched_features;
1368 extern unsigned int sysctl_sched_migration_cost;
1369 #endif
1370 
1371 extern unsigned int sysctl_sched_compat_yield;
1372 
1373 #ifdef CONFIG_RT_MUTEXES
1374 extern int rt_mutex_getprio(struct task_struct *p);
1375 extern void rt_mutex_setprio(struct task_struct *p, int prio);
1376 extern void rt_mutex_adjust_pi(struct task_struct *p);
1377 #else
1378 static inline int rt_mutex_getprio(struct task_struct *p)
1379 {
1380 	return p->normal_prio;
1381 }
1382 # define rt_mutex_adjust_pi(p)		do { } while (0)
1383 #endif
1384 
1385 extern void set_user_nice(struct task_struct *p, long nice);
1386 extern int task_prio(const struct task_struct *p);
1387 extern int task_nice(const struct task_struct *p);
1388 extern int can_nice(const struct task_struct *p, const int nice);
1389 extern int task_curr(const struct task_struct *p);
1390 extern int idle_cpu(int cpu);
1391 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1392 extern struct task_struct *idle_task(int cpu);
1393 extern struct task_struct *curr_task(int cpu);
1394 extern void set_curr_task(int cpu, struct task_struct *p);
1395 
1396 void yield(void);
1397 
1398 /*
1399  * The default (Linux) execution domain.
1400  */
1401 extern struct exec_domain	default_exec_domain;
1402 
1403 union thread_union {
1404 	struct thread_info thread_info;
1405 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1406 };
1407 
1408 #ifndef __HAVE_ARCH_KSTACK_END
1409 static inline int kstack_end(void *addr)
1410 {
1411 	/* Reliable end of stack detection:
1412 	 * Some APM bios versions misalign the stack
1413 	 */
1414 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1415 }
1416 #endif
1417 
1418 extern union thread_union init_thread_union;
1419 extern struct task_struct init_task;
1420 
1421 extern struct   mm_struct init_mm;
1422 
1423 #define find_task_by_pid(nr)	find_task_by_pid_type(PIDTYPE_PID, nr)
1424 extern struct task_struct *find_task_by_pid_type(int type, int pid);
1425 extern void __set_special_pids(pid_t session, pid_t pgrp);
1426 
1427 /* per-UID process charging. */
1428 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
1429 static inline struct user_struct *get_uid(struct user_struct *u)
1430 {
1431 	atomic_inc(&u->__count);
1432 	return u;
1433 }
1434 extern void free_uid(struct user_struct *);
1435 extern void switch_uid(struct user_struct *);
1436 extern void release_uids(struct user_namespace *ns);
1437 
1438 #include <asm/current.h>
1439 
1440 extern void do_timer(unsigned long ticks);
1441 
1442 extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
1443 extern int FASTCALL(wake_up_process(struct task_struct * tsk));
1444 extern void FASTCALL(wake_up_new_task(struct task_struct * tsk,
1445 						unsigned long clone_flags));
1446 #ifdef CONFIG_SMP
1447  extern void kick_process(struct task_struct *tsk);
1448 #else
1449  static inline void kick_process(struct task_struct *tsk) { }
1450 #endif
1451 extern void sched_fork(struct task_struct *p, int clone_flags);
1452 extern void sched_dead(struct task_struct *p);
1453 
1454 extern int in_group_p(gid_t);
1455 extern int in_egroup_p(gid_t);
1456 
1457 extern void proc_caches_init(void);
1458 extern void flush_signals(struct task_struct *);
1459 extern void ignore_signals(struct task_struct *);
1460 extern void flush_signal_handlers(struct task_struct *, int force_default);
1461 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1462 
1463 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1464 {
1465 	unsigned long flags;
1466 	int ret;
1467 
1468 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
1469 	ret = dequeue_signal(tsk, mask, info);
1470 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1471 
1472 	return ret;
1473 }
1474 
1475 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1476 			      sigset_t *mask);
1477 extern void unblock_all_signals(void);
1478 extern void release_task(struct task_struct * p);
1479 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
1480 extern int send_group_sig_info(int, struct siginfo *, struct task_struct *);
1481 extern int force_sigsegv(int, struct task_struct *);
1482 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
1483 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
1484 extern int kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
1485 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
1486 extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
1487 extern int kill_pgrp(struct pid *pid, int sig, int priv);
1488 extern int kill_pid(struct pid *pid, int sig, int priv);
1489 extern int kill_proc_info(int, struct siginfo *, pid_t);
1490 extern void do_notify_parent(struct task_struct *, int);
1491 extern void force_sig(int, struct task_struct *);
1492 extern void force_sig_specific(int, struct task_struct *);
1493 extern int send_sig(int, struct task_struct *, int);
1494 extern void zap_other_threads(struct task_struct *p);
1495 extern int kill_proc(pid_t, int, int);
1496 extern struct sigqueue *sigqueue_alloc(void);
1497 extern void sigqueue_free(struct sigqueue *);
1498 extern int send_sigqueue(int, struct sigqueue *,  struct task_struct *);
1499 extern int send_group_sigqueue(int, struct sigqueue *,  struct task_struct *);
1500 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
1501 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1502 
1503 static inline int kill_cad_pid(int sig, int priv)
1504 {
1505 	return kill_pid(cad_pid, sig, priv);
1506 }
1507 
1508 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
1509 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
1510 #define SEND_SIG_PRIV	((struct siginfo *) 1)
1511 #define SEND_SIG_FORCED	((struct siginfo *) 2)
1512 
1513 static inline int is_si_special(const struct siginfo *info)
1514 {
1515 	return info <= SEND_SIG_FORCED;
1516 }
1517 
1518 /* True if we are on the alternate signal stack.  */
1519 
1520 static inline int on_sig_stack(unsigned long sp)
1521 {
1522 	return (sp - current->sas_ss_sp < current->sas_ss_size);
1523 }
1524 
1525 static inline int sas_ss_flags(unsigned long sp)
1526 {
1527 	return (current->sas_ss_size == 0 ? SS_DISABLE
1528 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
1529 }
1530 
1531 /*
1532  * Routines for handling mm_structs
1533  */
1534 extern struct mm_struct * mm_alloc(void);
1535 
1536 /* mmdrop drops the mm and the page tables */
1537 extern void FASTCALL(__mmdrop(struct mm_struct *));
1538 static inline void mmdrop(struct mm_struct * mm)
1539 {
1540 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
1541 		__mmdrop(mm);
1542 }
1543 
1544 /* mmput gets rid of the mappings and all user-space */
1545 extern void mmput(struct mm_struct *);
1546 /* Grab a reference to a task's mm, if it is not already going away */
1547 extern struct mm_struct *get_task_mm(struct task_struct *task);
1548 /* Remove the current tasks stale references to the old mm_struct */
1549 extern void mm_release(struct task_struct *, struct mm_struct *);
1550 
1551 extern int  copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
1552 extern void flush_thread(void);
1553 extern void exit_thread(void);
1554 
1555 extern void exit_files(struct task_struct *);
1556 extern void __cleanup_signal(struct signal_struct *);
1557 extern void __cleanup_sighand(struct sighand_struct *);
1558 extern void exit_itimers(struct signal_struct *);
1559 
1560 extern NORET_TYPE void do_group_exit(int);
1561 
1562 extern void daemonize(const char *, ...);
1563 extern int allow_signal(int);
1564 extern int disallow_signal(int);
1565 
1566 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1567 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
1568 struct task_struct *fork_idle(int);
1569 
1570 extern void set_task_comm(struct task_struct *tsk, char *from);
1571 extern void get_task_comm(char *to, struct task_struct *tsk);
1572 
1573 #ifdef CONFIG_SMP
1574 extern void wait_task_inactive(struct task_struct * p);
1575 #else
1576 #define wait_task_inactive(p)	do { } while (0)
1577 #endif
1578 
1579 #define remove_parent(p)	list_del_init(&(p)->sibling)
1580 #define add_parent(p)		list_add_tail(&(p)->sibling,&(p)->parent->children)
1581 
1582 #define next_task(p)	list_entry(rcu_dereference((p)->tasks.next), struct task_struct, tasks)
1583 
1584 #define for_each_process(p) \
1585 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
1586 
1587 /*
1588  * Careful: do_each_thread/while_each_thread is a double loop so
1589  *          'break' will not work as expected - use goto instead.
1590  */
1591 #define do_each_thread(g, t) \
1592 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
1593 
1594 #define while_each_thread(g, t) \
1595 	while ((t = next_thread(t)) != g)
1596 
1597 /* de_thread depends on thread_group_leader not being a pid based check */
1598 #define thread_group_leader(p)	(p == p->group_leader)
1599 
1600 /* Do to the insanities of de_thread it is possible for a process
1601  * to have the pid of the thread group leader without actually being
1602  * the thread group leader.  For iteration through the pids in proc
1603  * all we care about is that we have a task with the appropriate
1604  * pid, we don't actually care if we have the right task.
1605  */
1606 static inline int has_group_leader_pid(struct task_struct *p)
1607 {
1608 	return p->pid == p->tgid;
1609 }
1610 
1611 static inline struct task_struct *next_thread(const struct task_struct *p)
1612 {
1613 	return list_entry(rcu_dereference(p->thread_group.next),
1614 			  struct task_struct, thread_group);
1615 }
1616 
1617 static inline int thread_group_empty(struct task_struct *p)
1618 {
1619 	return list_empty(&p->thread_group);
1620 }
1621 
1622 #define delay_group_leader(p) \
1623 		(thread_group_leader(p) && !thread_group_empty(p))
1624 
1625 /*
1626  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
1627  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
1628  * pins the final release of task.io_context.  Also protects ->cpuset.
1629  *
1630  * Nests both inside and outside of read_lock(&tasklist_lock).
1631  * It must not be nested with write_lock_irq(&tasklist_lock),
1632  * neither inside nor outside.
1633  */
1634 static inline void task_lock(struct task_struct *p)
1635 {
1636 	spin_lock(&p->alloc_lock);
1637 }
1638 
1639 static inline void task_unlock(struct task_struct *p)
1640 {
1641 	spin_unlock(&p->alloc_lock);
1642 }
1643 
1644 extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
1645 							unsigned long *flags);
1646 
1647 static inline void unlock_task_sighand(struct task_struct *tsk,
1648 						unsigned long *flags)
1649 {
1650 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
1651 }
1652 
1653 #ifndef __HAVE_THREAD_FUNCTIONS
1654 
1655 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
1656 #define task_stack_page(task)	((task)->stack)
1657 
1658 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
1659 {
1660 	*task_thread_info(p) = *task_thread_info(org);
1661 	task_thread_info(p)->task = p;
1662 }
1663 
1664 static inline unsigned long *end_of_stack(struct task_struct *p)
1665 {
1666 	return (unsigned long *)(task_thread_info(p) + 1);
1667 }
1668 
1669 #endif
1670 
1671 /* set thread flags in other task's structures
1672  * - see asm/thread_info.h for TIF_xxxx flags available
1673  */
1674 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1675 {
1676 	set_ti_thread_flag(task_thread_info(tsk), flag);
1677 }
1678 
1679 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1680 {
1681 	clear_ti_thread_flag(task_thread_info(tsk), flag);
1682 }
1683 
1684 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1685 {
1686 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1687 }
1688 
1689 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1690 {
1691 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1692 }
1693 
1694 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1695 {
1696 	return test_ti_thread_flag(task_thread_info(tsk), flag);
1697 }
1698 
1699 static inline void set_tsk_need_resched(struct task_struct *tsk)
1700 {
1701 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1702 }
1703 
1704 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1705 {
1706 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1707 }
1708 
1709 static inline int signal_pending(struct task_struct *p)
1710 {
1711 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
1712 }
1713 
1714 static inline int need_resched(void)
1715 {
1716 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
1717 }
1718 
1719 /*
1720  * cond_resched() and cond_resched_lock(): latency reduction via
1721  * explicit rescheduling in places that are safe. The return
1722  * value indicates whether a reschedule was done in fact.
1723  * cond_resched_lock() will drop the spinlock before scheduling,
1724  * cond_resched_softirq() will enable bhs before scheduling.
1725  */
1726 extern int cond_resched(void);
1727 extern int cond_resched_lock(spinlock_t * lock);
1728 extern int cond_resched_softirq(void);
1729 
1730 /*
1731  * Does a critical section need to be broken due to another
1732  * task waiting?:
1733  */
1734 #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
1735 # define need_lockbreak(lock) ((lock)->break_lock)
1736 #else
1737 # define need_lockbreak(lock) 0
1738 #endif
1739 
1740 /*
1741  * Does a critical section need to be broken due to another
1742  * task waiting or preemption being signalled:
1743  */
1744 static inline int lock_need_resched(spinlock_t *lock)
1745 {
1746 	if (need_lockbreak(lock) || need_resched())
1747 		return 1;
1748 	return 0;
1749 }
1750 
1751 /*
1752  * Reevaluate whether the task has signals pending delivery.
1753  * Wake the task if so.
1754  * This is required every time the blocked sigset_t changes.
1755  * callers must hold sighand->siglock.
1756  */
1757 extern void recalc_sigpending_and_wake(struct task_struct *t);
1758 extern void recalc_sigpending(void);
1759 
1760 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
1761 
1762 /*
1763  * Wrappers for p->thread_info->cpu access. No-op on UP.
1764  */
1765 #ifdef CONFIG_SMP
1766 
1767 static inline unsigned int task_cpu(const struct task_struct *p)
1768 {
1769 	return task_thread_info(p)->cpu;
1770 }
1771 
1772 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1773 
1774 #else
1775 
1776 static inline unsigned int task_cpu(const struct task_struct *p)
1777 {
1778 	return 0;
1779 }
1780 
1781 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1782 {
1783 }
1784 
1785 #endif /* CONFIG_SMP */
1786 
1787 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1788 extern void arch_pick_mmap_layout(struct mm_struct *mm);
1789 #else
1790 static inline void arch_pick_mmap_layout(struct mm_struct *mm)
1791 {
1792 	mm->mmap_base = TASK_UNMAPPED_BASE;
1793 	mm->get_unmapped_area = arch_get_unmapped_area;
1794 	mm->unmap_area = arch_unmap_area;
1795 }
1796 #endif
1797 
1798 extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
1799 extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
1800 
1801 extern int sched_mc_power_savings, sched_smt_power_savings;
1802 
1803 extern void normalize_rt_tasks(void);
1804 
1805 #ifdef CONFIG_FAIR_GROUP_SCHED
1806 
1807 extern struct task_group init_task_group;
1808 
1809 extern struct task_group *sched_create_group(void);
1810 extern void sched_destroy_group(struct task_group *tg);
1811 extern void sched_move_task(struct task_struct *tsk);
1812 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
1813 extern unsigned long sched_group_shares(struct task_group *tg);
1814 
1815 #endif
1816 
1817 #ifdef CONFIG_TASK_XACCT
1818 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
1819 {
1820 	tsk->rchar += amt;
1821 }
1822 
1823 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
1824 {
1825 	tsk->wchar += amt;
1826 }
1827 
1828 static inline void inc_syscr(struct task_struct *tsk)
1829 {
1830 	tsk->syscr++;
1831 }
1832 
1833 static inline void inc_syscw(struct task_struct *tsk)
1834 {
1835 	tsk->syscw++;
1836 }
1837 #else
1838 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
1839 {
1840 }
1841 
1842 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
1843 {
1844 }
1845 
1846 static inline void inc_syscr(struct task_struct *tsk)
1847 {
1848 }
1849 
1850 static inline void inc_syscw(struct task_struct *tsk)
1851 {
1852 }
1853 #endif
1854 
1855 #endif /* __KERNEL__ */
1856 
1857 #endif
1858