xref: /linux/include/linux/sched.h (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3 
4 #include <asm/param.h>	/* for HZ */
5 
6 #include <linux/config.h>
7 #include <linux/capability.h>
8 #include <linux/threads.h>
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/timex.h>
12 #include <linux/jiffies.h>
13 #include <linux/rbtree.h>
14 #include <linux/thread_info.h>
15 #include <linux/cpumask.h>
16 #include <linux/errno.h>
17 #include <linux/nodemask.h>
18 
19 #include <asm/system.h>
20 #include <asm/semaphore.h>
21 #include <asm/page.h>
22 #include <asm/ptrace.h>
23 #include <asm/mmu.h>
24 #include <asm/cputime.h>
25 
26 #include <linux/smp.h>
27 #include <linux/sem.h>
28 #include <linux/signal.h>
29 #include <linux/securebits.h>
30 #include <linux/fs_struct.h>
31 #include <linux/compiler.h>
32 #include <linux/completion.h>
33 #include <linux/pid.h>
34 #include <linux/percpu.h>
35 #include <linux/topology.h>
36 #include <linux/seccomp.h>
37 
38 #include <linux/auxvec.h>	/* For AT_VECTOR_SIZE */
39 
40 struct exec_domain;
41 
42 /*
43  * cloning flags:
44  */
45 #define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
46 #define CLONE_VM	0x00000100	/* set if VM shared between processes */
47 #define CLONE_FS	0x00000200	/* set if fs info shared between processes */
48 #define CLONE_FILES	0x00000400	/* set if open files shared between processes */
49 #define CLONE_SIGHAND	0x00000800	/* set if signal handlers and blocked signals shared */
50 #define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
51 #define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */
52 #define CLONE_PARENT	0x00008000	/* set if we want to have the same parent as the cloner */
53 #define CLONE_THREAD	0x00010000	/* Same thread group? */
54 #define CLONE_NEWNS	0x00020000	/* New namespace group? */
55 #define CLONE_SYSVSEM	0x00040000	/* share system V SEM_UNDO semantics */
56 #define CLONE_SETTLS	0x00080000	/* create a new TLS for the child */
57 #define CLONE_PARENT_SETTID	0x00100000	/* set the TID in the parent */
58 #define CLONE_CHILD_CLEARTID	0x00200000	/* clear the TID in the child */
59 #define CLONE_DETACHED		0x00400000	/* Unused, ignored */
60 #define CLONE_UNTRACED		0x00800000	/* set if the tracing process can't force CLONE_PTRACE on this clone */
61 #define CLONE_CHILD_SETTID	0x01000000	/* set the TID in the child */
62 #define CLONE_STOPPED		0x02000000	/* Start in stopped state */
63 
64 /*
65  * List of flags we want to share for kernel threads,
66  * if only because they are not used by them anyway.
67  */
68 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
69 
70 /*
71  * These are the constant used to fake the fixed-point load-average
72  * counting. Some notes:
73  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
74  *    a load-average precision of 10 bits integer + 11 bits fractional
75  *  - if you want to count load-averages more often, you need more
76  *    precision, or rounding will get you. With 2-second counting freq,
77  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
78  *    11 bit fractions.
79  */
80 extern unsigned long avenrun[];		/* Load averages */
81 
82 #define FSHIFT		11		/* nr of bits of precision */
83 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
84 #define LOAD_FREQ	(5*HZ)		/* 5 sec intervals */
85 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
86 #define EXP_5		2014		/* 1/exp(5sec/5min) */
87 #define EXP_15		2037		/* 1/exp(5sec/15min) */
88 
89 #define CALC_LOAD(load,exp,n) \
90 	load *= exp; \
91 	load += n*(FIXED_1-exp); \
92 	load >>= FSHIFT;
93 
94 extern unsigned long total_forks;
95 extern int nr_threads;
96 extern int last_pid;
97 DECLARE_PER_CPU(unsigned long, process_counts);
98 extern int nr_processes(void);
99 extern unsigned long nr_running(void);
100 extern unsigned long nr_uninterruptible(void);
101 extern unsigned long nr_iowait(void);
102 
103 #include <linux/time.h>
104 #include <linux/param.h>
105 #include <linux/resource.h>
106 #include <linux/timer.h>
107 
108 #include <asm/processor.h>
109 
110 /*
111  * Task state bitmask. NOTE! These bits are also
112  * encoded in fs/proc/array.c: get_task_state().
113  *
114  * We have two separate sets of flags: task->state
115  * is about runnability, while task->exit_state are
116  * about the task exiting. Confusing, but this way
117  * modifying one set can't modify the other one by
118  * mistake.
119  */
120 #define TASK_RUNNING		0
121 #define TASK_INTERRUPTIBLE	1
122 #define TASK_UNINTERRUPTIBLE	2
123 #define TASK_STOPPED		4
124 #define TASK_TRACED		8
125 /* in tsk->exit_state */
126 #define EXIT_ZOMBIE		16
127 #define EXIT_DEAD		32
128 /* in tsk->state again */
129 #define TASK_NONINTERACTIVE	64
130 
131 #define __set_task_state(tsk, state_value)		\
132 	do { (tsk)->state = (state_value); } while (0)
133 #define set_task_state(tsk, state_value)		\
134 	set_mb((tsk)->state, (state_value))
135 
136 /*
137  * set_current_state() includes a barrier so that the write of current->state
138  * is correctly serialised wrt the caller's subsequent test of whether to
139  * actually sleep:
140  *
141  *	set_current_state(TASK_UNINTERRUPTIBLE);
142  *	if (do_i_need_to_sleep())
143  *		schedule();
144  *
145  * If the caller does not need such serialisation then use __set_current_state()
146  */
147 #define __set_current_state(state_value)			\
148 	do { current->state = (state_value); } while (0)
149 #define set_current_state(state_value)		\
150 	set_mb(current->state, (state_value))
151 
152 /* Task command name length */
153 #define TASK_COMM_LEN 16
154 
155 /*
156  * Scheduling policies
157  */
158 #define SCHED_NORMAL		0
159 #define SCHED_FIFO		1
160 #define SCHED_RR		2
161 
162 struct sched_param {
163 	int sched_priority;
164 };
165 
166 #ifdef __KERNEL__
167 
168 #include <linux/spinlock.h>
169 
170 /*
171  * This serializes "schedule()" and also protects
172  * the run-queue from deletions/modifications (but
173  * _adding_ to the beginning of the run-queue has
174  * a separate lock).
175  */
176 extern rwlock_t tasklist_lock;
177 extern spinlock_t mmlist_lock;
178 
179 typedef struct task_struct task_t;
180 
181 extern void sched_init(void);
182 extern void sched_init_smp(void);
183 extern void init_idle(task_t *idle, int cpu);
184 
185 extern cpumask_t nohz_cpu_mask;
186 
187 extern void show_state(void);
188 extern void show_regs(struct pt_regs *);
189 
190 /*
191  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
192  * task), SP is the stack pointer of the first frame that should be shown in the back
193  * trace (or NULL if the entire call-chain of the task should be shown).
194  */
195 extern void show_stack(struct task_struct *task, unsigned long *sp);
196 
197 void io_schedule(void);
198 long io_schedule_timeout(long timeout);
199 
200 extern void cpu_init (void);
201 extern void trap_init(void);
202 extern void update_process_times(int user);
203 extern void scheduler_tick(void);
204 
205 #ifdef CONFIG_DETECT_SOFTLOCKUP
206 extern void softlockup_tick(struct pt_regs *regs);
207 extern void spawn_softlockup_task(void);
208 extern void touch_softlockup_watchdog(void);
209 #else
210 static inline void softlockup_tick(struct pt_regs *regs)
211 {
212 }
213 static inline void spawn_softlockup_task(void)
214 {
215 }
216 static inline void touch_softlockup_watchdog(void)
217 {
218 }
219 #endif
220 
221 
222 /* Attach to any functions which should be ignored in wchan output. */
223 #define __sched		__attribute__((__section__(".sched.text")))
224 /* Is this address in the __sched functions? */
225 extern int in_sched_functions(unsigned long addr);
226 
227 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
228 extern signed long FASTCALL(schedule_timeout(signed long timeout));
229 extern signed long schedule_timeout_interruptible(signed long timeout);
230 extern signed long schedule_timeout_uninterruptible(signed long timeout);
231 asmlinkage void schedule(void);
232 
233 struct namespace;
234 
235 /* Maximum number of active map areas.. This is a random (large) number */
236 #define DEFAULT_MAX_MAP_COUNT	65536
237 
238 extern int sysctl_max_map_count;
239 
240 #include <linux/aio.h>
241 
242 extern unsigned long
243 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
244 		       unsigned long, unsigned long);
245 extern unsigned long
246 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
247 			  unsigned long len, unsigned long pgoff,
248 			  unsigned long flags);
249 extern void arch_unmap_area(struct mm_struct *, unsigned long);
250 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
251 
252 #if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
253 /*
254  * The mm counters are not protected by its page_table_lock,
255  * so must be incremented atomically.
256  */
257 #ifdef ATOMIC64_INIT
258 #define set_mm_counter(mm, member, value) atomic64_set(&(mm)->_##member, value)
259 #define get_mm_counter(mm, member) ((unsigned long)atomic64_read(&(mm)->_##member))
260 #define add_mm_counter(mm, member, value) atomic64_add(value, &(mm)->_##member)
261 #define inc_mm_counter(mm, member) atomic64_inc(&(mm)->_##member)
262 #define dec_mm_counter(mm, member) atomic64_dec(&(mm)->_##member)
263 typedef atomic64_t mm_counter_t;
264 #else /* !ATOMIC64_INIT */
265 /*
266  * The counters wrap back to 0 at 2^32 * PAGE_SIZE,
267  * that is, at 16TB if using 4kB page size.
268  */
269 #define set_mm_counter(mm, member, value) atomic_set(&(mm)->_##member, value)
270 #define get_mm_counter(mm, member) ((unsigned long)atomic_read(&(mm)->_##member))
271 #define add_mm_counter(mm, member, value) atomic_add(value, &(mm)->_##member)
272 #define inc_mm_counter(mm, member) atomic_inc(&(mm)->_##member)
273 #define dec_mm_counter(mm, member) atomic_dec(&(mm)->_##member)
274 typedef atomic_t mm_counter_t;
275 #endif /* !ATOMIC64_INIT */
276 
277 #else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
278 /*
279  * The mm counters are protected by its page_table_lock,
280  * so can be incremented directly.
281  */
282 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
283 #define get_mm_counter(mm, member) ((mm)->_##member)
284 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
285 #define inc_mm_counter(mm, member) (mm)->_##member++
286 #define dec_mm_counter(mm, member) (mm)->_##member--
287 typedef unsigned long mm_counter_t;
288 
289 #endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
290 
291 #define get_mm_rss(mm)					\
292 	(get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
293 #define update_hiwater_rss(mm)	do {			\
294 	unsigned long _rss = get_mm_rss(mm);		\
295 	if ((mm)->hiwater_rss < _rss)			\
296 		(mm)->hiwater_rss = _rss;		\
297 } while (0)
298 #define update_hiwater_vm(mm)	do {			\
299 	if ((mm)->hiwater_vm < (mm)->total_vm)		\
300 		(mm)->hiwater_vm = (mm)->total_vm;	\
301 } while (0)
302 
303 struct mm_struct {
304 	struct vm_area_struct * mmap;		/* list of VMAs */
305 	struct rb_root mm_rb;
306 	struct vm_area_struct * mmap_cache;	/* last find_vma result */
307 	unsigned long (*get_unmapped_area) (struct file *filp,
308 				unsigned long addr, unsigned long len,
309 				unsigned long pgoff, unsigned long flags);
310 	void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
311         unsigned long mmap_base;		/* base of mmap area */
312         unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
313 	unsigned long free_area_cache;		/* first hole of size cached_hole_size or larger */
314 	pgd_t * pgd;
315 	atomic_t mm_users;			/* How many users with user space? */
316 	atomic_t mm_count;			/* How many references to "struct mm_struct" (users count as 1) */
317 	int map_count;				/* number of VMAs */
318 	struct rw_semaphore mmap_sem;
319 	spinlock_t page_table_lock;		/* Protects page tables and some counters */
320 
321 	struct list_head mmlist;		/* List of maybe swapped mm's.  These are globally strung
322 						 * together off init_mm.mmlist, and are protected
323 						 * by mmlist_lock
324 						 */
325 
326 	/* Special counters, in some configurations protected by the
327 	 * page_table_lock, in other configurations by being atomic.
328 	 */
329 	mm_counter_t _file_rss;
330 	mm_counter_t _anon_rss;
331 
332 	unsigned long hiwater_rss;	/* High-watermark of RSS usage */
333 	unsigned long hiwater_vm;	/* High-water virtual memory usage */
334 
335 	unsigned long total_vm, locked_vm, shared_vm, exec_vm;
336 	unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
337 	unsigned long start_code, end_code, start_data, end_data;
338 	unsigned long start_brk, brk, start_stack;
339 	unsigned long arg_start, arg_end, env_start, env_end;
340 
341 	unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
342 
343 	unsigned dumpable:2;
344 	cpumask_t cpu_vm_mask;
345 
346 	/* Architecture-specific MM context */
347 	mm_context_t context;
348 
349 	/* Token based thrashing protection. */
350 	unsigned long swap_token_time;
351 	char recent_pagein;
352 
353 	/* coredumping support */
354 	int core_waiters;
355 	struct completion *core_startup_done, core_done;
356 
357 	/* aio bits */
358 	rwlock_t		ioctx_list_lock;
359 	struct kioctx		*ioctx_list;
360 };
361 
362 struct sighand_struct {
363 	atomic_t		count;
364 	struct k_sigaction	action[_NSIG];
365 	spinlock_t		siglock;
366 };
367 
368 /*
369  * NOTE! "signal_struct" does not have it's own
370  * locking, because a shared signal_struct always
371  * implies a shared sighand_struct, so locking
372  * sighand_struct is always a proper superset of
373  * the locking of signal_struct.
374  */
375 struct signal_struct {
376 	atomic_t		count;
377 	atomic_t		live;
378 
379 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
380 
381 	/* current thread group signal load-balancing target: */
382 	task_t			*curr_target;
383 
384 	/* shared signal handling: */
385 	struct sigpending	shared_pending;
386 
387 	/* thread group exit support */
388 	int			group_exit_code;
389 	/* overloaded:
390 	 * - notify group_exit_task when ->count is equal to notify_count
391 	 * - everyone except group_exit_task is stopped during signal delivery
392 	 *   of fatal signals, group_exit_task processes the signal.
393 	 */
394 	struct task_struct	*group_exit_task;
395 	int			notify_count;
396 
397 	/* thread group stop support, overloads group_exit_code too */
398 	int			group_stop_count;
399 	unsigned int		flags; /* see SIGNAL_* flags below */
400 
401 	/* POSIX.1b Interval Timers */
402 	struct list_head posix_timers;
403 
404 	/* ITIMER_REAL timer for the process */
405 	struct timer_list real_timer;
406 	unsigned long it_real_value, it_real_incr;
407 
408 	/* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
409 	cputime_t it_prof_expires, it_virt_expires;
410 	cputime_t it_prof_incr, it_virt_incr;
411 
412 	/* job control IDs */
413 	pid_t pgrp;
414 	pid_t tty_old_pgrp;
415 	pid_t session;
416 	/* boolean value for session group leader */
417 	int leader;
418 
419 	struct tty_struct *tty; /* NULL if no tty */
420 
421 	/*
422 	 * Cumulative resource counters for dead threads in the group,
423 	 * and for reaped dead child processes forked by this group.
424 	 * Live threads maintain their own counters and add to these
425 	 * in __exit_signal, except for the group leader.
426 	 */
427 	cputime_t utime, stime, cutime, cstime;
428 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
429 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
430 
431 	/*
432 	 * Cumulative ns of scheduled CPU time for dead threads in the
433 	 * group, not including a zombie group leader.  (This only differs
434 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
435 	 * other than jiffies.)
436 	 */
437 	unsigned long long sched_time;
438 
439 	/*
440 	 * We don't bother to synchronize most readers of this at all,
441 	 * because there is no reader checking a limit that actually needs
442 	 * to get both rlim_cur and rlim_max atomically, and either one
443 	 * alone is a single word that can safely be read normally.
444 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
445 	 * protect this instead of the siglock, because they really
446 	 * have no need to disable irqs.
447 	 */
448 	struct rlimit rlim[RLIM_NLIMITS];
449 
450 	struct list_head cpu_timers[3];
451 
452 	/* keep the process-shared keyrings here so that they do the right
453 	 * thing in threads created with CLONE_THREAD */
454 #ifdef CONFIG_KEYS
455 	struct key *session_keyring;	/* keyring inherited over fork */
456 	struct key *process_keyring;	/* keyring private to this process */
457 #endif
458 };
459 
460 /* Context switch must be unlocked if interrupts are to be enabled */
461 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
462 # define __ARCH_WANT_UNLOCKED_CTXSW
463 #endif
464 
465 /*
466  * Bits in flags field of signal_struct.
467  */
468 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
469 #define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
470 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
471 #define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
472 
473 
474 /*
475  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
476  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL tasks are
477  * in the range MAX_RT_PRIO..MAX_PRIO-1. Priority values
478  * are inverted: lower p->prio value means higher priority.
479  *
480  * The MAX_USER_RT_PRIO value allows the actual maximum
481  * RT priority to be separate from the value exported to
482  * user-space.  This allows kernel threads to set their
483  * priority to a value higher than any user task. Note:
484  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
485  */
486 
487 #define MAX_USER_RT_PRIO	100
488 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
489 
490 #define MAX_PRIO		(MAX_RT_PRIO + 40)
491 
492 #define rt_task(p)		(unlikely((p)->prio < MAX_RT_PRIO))
493 
494 /*
495  * Some day this will be a full-fledged user tracking system..
496  */
497 struct user_struct {
498 	atomic_t __count;	/* reference count */
499 	atomic_t processes;	/* How many processes does this user have? */
500 	atomic_t files;		/* How many open files does this user have? */
501 	atomic_t sigpending;	/* How many pending signals does this user have? */
502 #ifdef CONFIG_INOTIFY
503 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
504 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
505 #endif
506 	/* protected by mq_lock	*/
507 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
508 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
509 
510 #ifdef CONFIG_KEYS
511 	struct key *uid_keyring;	/* UID specific keyring */
512 	struct key *session_keyring;	/* UID's default session keyring */
513 #endif
514 
515 	/* Hash table maintenance information */
516 	struct list_head uidhash_list;
517 	uid_t uid;
518 };
519 
520 extern struct user_struct *find_user(uid_t);
521 
522 extern struct user_struct root_user;
523 #define INIT_USER (&root_user)
524 
525 typedef struct prio_array prio_array_t;
526 struct backing_dev_info;
527 struct reclaim_state;
528 
529 #ifdef CONFIG_SCHEDSTATS
530 struct sched_info {
531 	/* cumulative counters */
532 	unsigned long	cpu_time,	/* time spent on the cpu */
533 			run_delay,	/* time spent waiting on a runqueue */
534 			pcnt;		/* # of timeslices run on this cpu */
535 
536 	/* timestamps */
537 	unsigned long	last_arrival,	/* when we last ran on a cpu */
538 			last_queued;	/* when we were last queued to run */
539 };
540 
541 extern struct file_operations proc_schedstat_operations;
542 #endif
543 
544 enum idle_type
545 {
546 	SCHED_IDLE,
547 	NOT_IDLE,
548 	NEWLY_IDLE,
549 	MAX_IDLE_TYPES
550 };
551 
552 /*
553  * sched-domains (multiprocessor balancing) declarations:
554  */
555 #ifdef CONFIG_SMP
556 #define SCHED_LOAD_SCALE	128UL	/* increase resolution of load */
557 
558 #define SD_LOAD_BALANCE		1	/* Do load balancing on this domain. */
559 #define SD_BALANCE_NEWIDLE	2	/* Balance when about to become idle */
560 #define SD_BALANCE_EXEC		4	/* Balance on exec */
561 #define SD_BALANCE_FORK		8	/* Balance on fork, clone */
562 #define SD_WAKE_IDLE		16	/* Wake to idle CPU on task wakeup */
563 #define SD_WAKE_AFFINE		32	/* Wake task to waking CPU */
564 #define SD_WAKE_BALANCE		64	/* Perform balancing at task wakeup */
565 #define SD_SHARE_CPUPOWER	128	/* Domain members share cpu power */
566 
567 struct sched_group {
568 	struct sched_group *next;	/* Must be a circular list */
569 	cpumask_t cpumask;
570 
571 	/*
572 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
573 	 * single CPU. This is read only (except for setup, hotplug CPU).
574 	 */
575 	unsigned long cpu_power;
576 };
577 
578 struct sched_domain {
579 	/* These fields must be setup */
580 	struct sched_domain *parent;	/* top domain must be null terminated */
581 	struct sched_group *groups;	/* the balancing groups of the domain */
582 	cpumask_t span;			/* span of all CPUs in this domain */
583 	unsigned long min_interval;	/* Minimum balance interval ms */
584 	unsigned long max_interval;	/* Maximum balance interval ms */
585 	unsigned int busy_factor;	/* less balancing by factor if busy */
586 	unsigned int imbalance_pct;	/* No balance until over watermark */
587 	unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
588 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
589 	unsigned int per_cpu_gain;	/* CPU % gained by adding domain cpus */
590 	unsigned int busy_idx;
591 	unsigned int idle_idx;
592 	unsigned int newidle_idx;
593 	unsigned int wake_idx;
594 	unsigned int forkexec_idx;
595 	int flags;			/* See SD_* */
596 
597 	/* Runtime fields. */
598 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
599 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
600 	unsigned int nr_balance_failed; /* initialise to 0 */
601 
602 #ifdef CONFIG_SCHEDSTATS
603 	/* load_balance() stats */
604 	unsigned long lb_cnt[MAX_IDLE_TYPES];
605 	unsigned long lb_failed[MAX_IDLE_TYPES];
606 	unsigned long lb_balanced[MAX_IDLE_TYPES];
607 	unsigned long lb_imbalance[MAX_IDLE_TYPES];
608 	unsigned long lb_gained[MAX_IDLE_TYPES];
609 	unsigned long lb_hot_gained[MAX_IDLE_TYPES];
610 	unsigned long lb_nobusyg[MAX_IDLE_TYPES];
611 	unsigned long lb_nobusyq[MAX_IDLE_TYPES];
612 
613 	/* Active load balancing */
614 	unsigned long alb_cnt;
615 	unsigned long alb_failed;
616 	unsigned long alb_pushed;
617 
618 	/* SD_BALANCE_EXEC stats */
619 	unsigned long sbe_cnt;
620 	unsigned long sbe_balanced;
621 	unsigned long sbe_pushed;
622 
623 	/* SD_BALANCE_FORK stats */
624 	unsigned long sbf_cnt;
625 	unsigned long sbf_balanced;
626 	unsigned long sbf_pushed;
627 
628 	/* try_to_wake_up() stats */
629 	unsigned long ttwu_wake_remote;
630 	unsigned long ttwu_move_affine;
631 	unsigned long ttwu_move_balance;
632 #endif
633 };
634 
635 extern void partition_sched_domains(cpumask_t *partition1,
636 				    cpumask_t *partition2);
637 #endif /* CONFIG_SMP */
638 
639 
640 struct io_context;			/* See blkdev.h */
641 void exit_io_context(void);
642 struct cpuset;
643 
644 #define NGROUPS_SMALL		32
645 #define NGROUPS_PER_BLOCK	((int)(PAGE_SIZE / sizeof(gid_t)))
646 struct group_info {
647 	int ngroups;
648 	atomic_t usage;
649 	gid_t small_block[NGROUPS_SMALL];
650 	int nblocks;
651 	gid_t *blocks[0];
652 };
653 
654 /*
655  * get_group_info() must be called with the owning task locked (via task_lock())
656  * when task != current.  The reason being that the vast majority of callers are
657  * looking at current->group_info, which can not be changed except by the
658  * current task.  Changing current->group_info requires the task lock, too.
659  */
660 #define get_group_info(group_info) do { \
661 	atomic_inc(&(group_info)->usage); \
662 } while (0)
663 
664 #define put_group_info(group_info) do { \
665 	if (atomic_dec_and_test(&(group_info)->usage)) \
666 		groups_free(group_info); \
667 } while (0)
668 
669 extern struct group_info *groups_alloc(int gidsetsize);
670 extern void groups_free(struct group_info *group_info);
671 extern int set_current_groups(struct group_info *group_info);
672 extern int groups_search(struct group_info *group_info, gid_t grp);
673 /* access the groups "array" with this macro */
674 #define GROUP_AT(gi, i) \
675     ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK])
676 
677 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
678 extern void prefetch_stack(struct task_struct*);
679 #else
680 static inline void prefetch_stack(struct task_struct *t) { }
681 #endif
682 
683 struct audit_context;		/* See audit.c */
684 struct mempolicy;
685 
686 struct task_struct {
687 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
688 	struct thread_info *thread_info;
689 	atomic_t usage;
690 	unsigned long flags;	/* per process flags, defined below */
691 	unsigned long ptrace;
692 
693 	int lock_depth;		/* BKL lock depth */
694 
695 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
696 	int oncpu;
697 #endif
698 	int prio, static_prio;
699 	struct list_head run_list;
700 	prio_array_t *array;
701 
702 	unsigned short ioprio;
703 
704 	unsigned long sleep_avg;
705 	unsigned long long timestamp, last_ran;
706 	unsigned long long sched_time; /* sched_clock time spent running */
707 	int activated;
708 
709 	unsigned long policy;
710 	cpumask_t cpus_allowed;
711 	unsigned int time_slice, first_time_slice;
712 
713 #ifdef CONFIG_SCHEDSTATS
714 	struct sched_info sched_info;
715 #endif
716 
717 	struct list_head tasks;
718 	/*
719 	 * ptrace_list/ptrace_children forms the list of my children
720 	 * that were stolen by a ptracer.
721 	 */
722 	struct list_head ptrace_children;
723 	struct list_head ptrace_list;
724 
725 	struct mm_struct *mm, *active_mm;
726 
727 /* task state */
728 	struct linux_binfmt *binfmt;
729 	long exit_state;
730 	int exit_code, exit_signal;
731 	int pdeath_signal;  /*  The signal sent when the parent dies  */
732 	/* ??? */
733 	unsigned long personality;
734 	unsigned did_exec:1;
735 	pid_t pid;
736 	pid_t tgid;
737 	/*
738 	 * pointers to (original) parent process, youngest child, younger sibling,
739 	 * older sibling, respectively.  (p->father can be replaced with
740 	 * p->parent->pid)
741 	 */
742 	struct task_struct *real_parent; /* real parent process (when being debugged) */
743 	struct task_struct *parent;	/* parent process */
744 	/*
745 	 * children/sibling forms the list of my children plus the
746 	 * tasks I'm ptracing.
747 	 */
748 	struct list_head children;	/* list of my children */
749 	struct list_head sibling;	/* linkage in my parent's children list */
750 	struct task_struct *group_leader;	/* threadgroup leader */
751 
752 	/* PID/PID hash table linkage. */
753 	struct pid pids[PIDTYPE_MAX];
754 
755 	struct completion *vfork_done;		/* for vfork() */
756 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
757 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
758 
759 	unsigned long rt_priority;
760 	cputime_t utime, stime;
761 	unsigned long nvcsw, nivcsw; /* context switch counts */
762 	struct timespec start_time;
763 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
764 	unsigned long min_flt, maj_flt;
765 
766   	cputime_t it_prof_expires, it_virt_expires;
767 	unsigned long long it_sched_expires;
768 	struct list_head cpu_timers[3];
769 
770 /* process credentials */
771 	uid_t uid,euid,suid,fsuid;
772 	gid_t gid,egid,sgid,fsgid;
773 	struct group_info *group_info;
774 	kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
775 	unsigned keep_capabilities:1;
776 	struct user_struct *user;
777 #ifdef CONFIG_KEYS
778 	struct key *thread_keyring;	/* keyring private to this thread */
779 	unsigned char jit_keyring;	/* default keyring to attach requested keys to */
780 #endif
781 	int oomkilladj; /* OOM kill score adjustment (bit shift). */
782 	char comm[TASK_COMM_LEN]; /* executable name excluding path
783 				     - access with [gs]et_task_comm (which lock
784 				       it with task_lock())
785 				     - initialized normally by flush_old_exec */
786 /* file system info */
787 	int link_count, total_link_count;
788 /* ipc stuff */
789 	struct sysv_sem sysvsem;
790 /* CPU-specific state of this task */
791 	struct thread_struct thread;
792 /* filesystem information */
793 	struct fs_struct *fs;
794 /* open file information */
795 	struct files_struct *files;
796 /* namespace */
797 	struct namespace *namespace;
798 /* signal handlers */
799 	struct signal_struct *signal;
800 	struct sighand_struct *sighand;
801 
802 	sigset_t blocked, real_blocked;
803 	struct sigpending pending;
804 
805 	unsigned long sas_ss_sp;
806 	size_t sas_ss_size;
807 	int (*notifier)(void *priv);
808 	void *notifier_data;
809 	sigset_t *notifier_mask;
810 
811 	void *security;
812 	struct audit_context *audit_context;
813 	seccomp_t seccomp;
814 
815 /* Thread group tracking */
816    	u32 parent_exec_id;
817    	u32 self_exec_id;
818 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
819 	spinlock_t alloc_lock;
820 /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
821 	spinlock_t proc_lock;
822 
823 /* journalling filesystem info */
824 	void *journal_info;
825 
826 /* VM state */
827 	struct reclaim_state *reclaim_state;
828 
829 	struct dentry *proc_dentry;
830 	struct backing_dev_info *backing_dev_info;
831 
832 	struct io_context *io_context;
833 
834 	unsigned long ptrace_message;
835 	siginfo_t *last_siginfo; /* For ptrace use.  */
836 /*
837  * current io wait handle: wait queue entry to use for io waits
838  * If this thread is processing aio, this points at the waitqueue
839  * inside the currently handled kiocb. It may be NULL (i.e. default
840  * to a stack based synchronous wait) if its doing sync IO.
841  */
842 	wait_queue_t *io_wait;
843 /* i/o counters(bytes read/written, #syscalls */
844 	u64 rchar, wchar, syscr, syscw;
845 #if defined(CONFIG_BSD_PROCESS_ACCT)
846 	u64 acct_rss_mem1;	/* accumulated rss usage */
847 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
848 	clock_t acct_stimexpd;	/* clock_t-converted stime since last update */
849 #endif
850 #ifdef CONFIG_NUMA
851   	struct mempolicy *mempolicy;
852 	short il_next;
853 #endif
854 #ifdef CONFIG_CPUSETS
855 	struct cpuset *cpuset;
856 	nodemask_t mems_allowed;
857 	int cpuset_mems_generation;
858 #endif
859 	atomic_t fs_excl;	/* holding fs exclusive resources */
860 };
861 
862 static inline pid_t process_group(struct task_struct *tsk)
863 {
864 	return tsk->signal->pgrp;
865 }
866 
867 /**
868  * pid_alive - check that a task structure is not stale
869  * @p: Task structure to be checked.
870  *
871  * Test if a process is not yet dead (at most zombie state)
872  * If pid_alive fails, then pointers within the task structure
873  * can be stale and must not be dereferenced.
874  */
875 static inline int pid_alive(struct task_struct *p)
876 {
877 	return p->pids[PIDTYPE_PID].nr != 0;
878 }
879 
880 extern void free_task(struct task_struct *tsk);
881 extern void __put_task_struct(struct task_struct *tsk);
882 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
883 #define put_task_struct(tsk) \
884 do { if (atomic_dec_and_test(&(tsk)->usage)) __put_task_struct(tsk); } while(0)
885 
886 /*
887  * Per process flags
888  */
889 #define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
890 					/* Not implemented yet, only for 486*/
891 #define PF_STARTING	0x00000002	/* being created */
892 #define PF_EXITING	0x00000004	/* getting shut down */
893 #define PF_DEAD		0x00000008	/* Dead */
894 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
895 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
896 #define PF_DUMPCORE	0x00000200	/* dumped core */
897 #define PF_SIGNALED	0x00000400	/* killed by a signal */
898 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
899 #define PF_FLUSHER	0x00001000	/* responsible for disk writeback */
900 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
901 #define PF_FREEZE	0x00004000	/* this task is being frozen for suspend now */
902 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
903 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
904 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
905 #define PF_KSWAPD	0x00040000	/* I am kswapd */
906 #define PF_SWAPOFF	0x00080000	/* I am in swapoff */
907 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
908 #define PF_SYNCWRITE	0x00200000	/* I am doing a sync write */
909 #define PF_BORROWED_MM	0x00400000	/* I am a kthread doing use_mm */
910 #define PF_RANDOMIZE	0x00800000	/* randomize virtual address space */
911 
912 /*
913  * Only the _current_ task can read/write to tsk->flags, but other
914  * tasks can access tsk->flags in readonly mode for example
915  * with tsk_used_math (like during threaded core dumping).
916  * There is however an exception to this rule during ptrace
917  * or during fork: the ptracer task is allowed to write to the
918  * child->flags of its traced child (same goes for fork, the parent
919  * can write to the child->flags), because we're guaranteed the
920  * child is not running and in turn not changing child->flags
921  * at the same time the parent does it.
922  */
923 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
924 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
925 #define clear_used_math() clear_stopped_child_used_math(current)
926 #define set_used_math() set_stopped_child_used_math(current)
927 #define conditional_stopped_child_used_math(condition, child) \
928 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
929 #define conditional_used_math(condition) \
930 	conditional_stopped_child_used_math(condition, current)
931 #define copy_to_stopped_child_used_math(child) \
932 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
933 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
934 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
935 #define used_math() tsk_used_math(current)
936 
937 #ifdef CONFIG_SMP
938 extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
939 #else
940 static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)
941 {
942 	if (!cpu_isset(0, new_mask))
943 		return -EINVAL;
944 	return 0;
945 }
946 #endif
947 
948 extern unsigned long long sched_clock(void);
949 extern unsigned long long current_sched_time(const task_t *current_task);
950 
951 /* sched_exec is called by processes performing an exec */
952 #ifdef CONFIG_SMP
953 extern void sched_exec(void);
954 #else
955 #define sched_exec()   {}
956 #endif
957 
958 #ifdef CONFIG_HOTPLUG_CPU
959 extern void idle_task_exit(void);
960 #else
961 static inline void idle_task_exit(void) {}
962 #endif
963 
964 extern void sched_idle_next(void);
965 extern void set_user_nice(task_t *p, long nice);
966 extern int task_prio(const task_t *p);
967 extern int task_nice(const task_t *p);
968 extern int can_nice(const task_t *p, const int nice);
969 extern int task_curr(const task_t *p);
970 extern int idle_cpu(int cpu);
971 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
972 extern task_t *idle_task(int cpu);
973 extern task_t *curr_task(int cpu);
974 extern void set_curr_task(int cpu, task_t *p);
975 
976 void yield(void);
977 
978 /*
979  * The default (Linux) execution domain.
980  */
981 extern struct exec_domain	default_exec_domain;
982 
983 union thread_union {
984 	struct thread_info thread_info;
985 	unsigned long stack[THREAD_SIZE/sizeof(long)];
986 };
987 
988 #ifndef __HAVE_ARCH_KSTACK_END
989 static inline int kstack_end(void *addr)
990 {
991 	/* Reliable end of stack detection:
992 	 * Some APM bios versions misalign the stack
993 	 */
994 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
995 }
996 #endif
997 
998 extern union thread_union init_thread_union;
999 extern struct task_struct init_task;
1000 
1001 extern struct   mm_struct init_mm;
1002 
1003 #define find_task_by_pid(nr)	find_task_by_pid_type(PIDTYPE_PID, nr)
1004 extern struct task_struct *find_task_by_pid_type(int type, int pid);
1005 extern void set_special_pids(pid_t session, pid_t pgrp);
1006 extern void __set_special_pids(pid_t session, pid_t pgrp);
1007 
1008 /* per-UID process charging. */
1009 extern struct user_struct * alloc_uid(uid_t);
1010 static inline struct user_struct *get_uid(struct user_struct *u)
1011 {
1012 	atomic_inc(&u->__count);
1013 	return u;
1014 }
1015 extern void free_uid(struct user_struct *);
1016 extern void switch_uid(struct user_struct *);
1017 
1018 #include <asm/current.h>
1019 
1020 extern void do_timer(struct pt_regs *);
1021 
1022 extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
1023 extern int FASTCALL(wake_up_process(struct task_struct * tsk));
1024 extern void FASTCALL(wake_up_new_task(struct task_struct * tsk,
1025 						unsigned long clone_flags));
1026 #ifdef CONFIG_SMP
1027  extern void kick_process(struct task_struct *tsk);
1028 #else
1029  static inline void kick_process(struct task_struct *tsk) { }
1030 #endif
1031 extern void FASTCALL(sched_fork(task_t * p, int clone_flags));
1032 extern void FASTCALL(sched_exit(task_t * p));
1033 
1034 extern int in_group_p(gid_t);
1035 extern int in_egroup_p(gid_t);
1036 
1037 extern void proc_caches_init(void);
1038 extern void flush_signals(struct task_struct *);
1039 extern void flush_signal_handlers(struct task_struct *, int force_default);
1040 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1041 
1042 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1043 {
1044 	unsigned long flags;
1045 	int ret;
1046 
1047 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
1048 	ret = dequeue_signal(tsk, mask, info);
1049 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1050 
1051 	return ret;
1052 }
1053 
1054 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1055 			      sigset_t *mask);
1056 extern void unblock_all_signals(void);
1057 extern void release_task(struct task_struct * p);
1058 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
1059 extern int send_group_sig_info(int, struct siginfo *, struct task_struct *);
1060 extern int force_sigsegv(int, struct task_struct *);
1061 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
1062 extern int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp);
1063 extern int kill_pg_info(int, struct siginfo *, pid_t);
1064 extern int kill_proc_info(int, struct siginfo *, pid_t);
1065 extern int kill_proc_info_as_uid(int, struct siginfo *, pid_t, uid_t, uid_t);
1066 extern void do_notify_parent(struct task_struct *, int);
1067 extern void force_sig(int, struct task_struct *);
1068 extern void force_sig_specific(int, struct task_struct *);
1069 extern int send_sig(int, struct task_struct *, int);
1070 extern void zap_other_threads(struct task_struct *p);
1071 extern int kill_pg(pid_t, int, int);
1072 extern int kill_sl(pid_t, int, int);
1073 extern int kill_proc(pid_t, int, int);
1074 extern struct sigqueue *sigqueue_alloc(void);
1075 extern void sigqueue_free(struct sigqueue *);
1076 extern int send_sigqueue(int, struct sigqueue *,  struct task_struct *);
1077 extern int send_group_sigqueue(int, struct sigqueue *,  struct task_struct *);
1078 extern int do_sigaction(int, const struct k_sigaction *, struct k_sigaction *);
1079 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1080 
1081 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
1082 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
1083 #define SEND_SIG_PRIV	((struct siginfo *) 1)
1084 #define SEND_SIG_FORCED	((struct siginfo *) 2)
1085 
1086 static inline int is_si_special(const struct siginfo *info)
1087 {
1088 	return info <= SEND_SIG_FORCED;
1089 }
1090 
1091 /* True if we are on the alternate signal stack.  */
1092 
1093 static inline int on_sig_stack(unsigned long sp)
1094 {
1095 	return (sp - current->sas_ss_sp < current->sas_ss_size);
1096 }
1097 
1098 static inline int sas_ss_flags(unsigned long sp)
1099 {
1100 	return (current->sas_ss_size == 0 ? SS_DISABLE
1101 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
1102 }
1103 
1104 
1105 #ifdef CONFIG_SECURITY
1106 /* code is in security.c */
1107 extern int capable(int cap);
1108 #else
1109 static inline int capable(int cap)
1110 {
1111 	if (cap_raised(current->cap_effective, cap)) {
1112 		current->flags |= PF_SUPERPRIV;
1113 		return 1;
1114 	}
1115 	return 0;
1116 }
1117 #endif
1118 
1119 /*
1120  * Routines for handling mm_structs
1121  */
1122 extern struct mm_struct * mm_alloc(void);
1123 
1124 /* mmdrop drops the mm and the page tables */
1125 extern void FASTCALL(__mmdrop(struct mm_struct *));
1126 static inline void mmdrop(struct mm_struct * mm)
1127 {
1128 	if (atomic_dec_and_test(&mm->mm_count))
1129 		__mmdrop(mm);
1130 }
1131 
1132 /* mmput gets rid of the mappings and all user-space */
1133 extern void mmput(struct mm_struct *);
1134 /* Grab a reference to a task's mm, if it is not already going away */
1135 extern struct mm_struct *get_task_mm(struct task_struct *task);
1136 /* Remove the current tasks stale references to the old mm_struct */
1137 extern void mm_release(struct task_struct *, struct mm_struct *);
1138 
1139 extern int  copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
1140 extern void flush_thread(void);
1141 extern void exit_thread(void);
1142 
1143 extern void exit_files(struct task_struct *);
1144 extern void exit_signal(struct task_struct *);
1145 extern void __exit_signal(struct task_struct *);
1146 extern void exit_sighand(struct task_struct *);
1147 extern void __exit_sighand(struct task_struct *);
1148 extern void exit_itimers(struct signal_struct *);
1149 
1150 extern NORET_TYPE void do_group_exit(int);
1151 
1152 extern void daemonize(const char *, ...);
1153 extern int allow_signal(int);
1154 extern int disallow_signal(int);
1155 extern task_t *child_reaper;
1156 
1157 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1158 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
1159 task_t *fork_idle(int);
1160 
1161 extern void set_task_comm(struct task_struct *tsk, char *from);
1162 extern void get_task_comm(char *to, struct task_struct *tsk);
1163 
1164 #ifdef CONFIG_SMP
1165 extern void wait_task_inactive(task_t * p);
1166 #else
1167 #define wait_task_inactive(p)	do { } while (0)
1168 #endif
1169 
1170 #define remove_parent(p)	list_del_init(&(p)->sibling)
1171 #define add_parent(p, parent)	list_add_tail(&(p)->sibling,&(parent)->children)
1172 
1173 #define REMOVE_LINKS(p) do {					\
1174 	if (thread_group_leader(p))				\
1175 		list_del_init(&(p)->tasks);			\
1176 	remove_parent(p);					\
1177 	} while (0)
1178 
1179 #define SET_LINKS(p) do {					\
1180 	if (thread_group_leader(p))				\
1181 		list_add_tail(&(p)->tasks,&init_task.tasks);	\
1182 	add_parent(p, (p)->parent);				\
1183 	} while (0)
1184 
1185 #define next_task(p)	list_entry((p)->tasks.next, struct task_struct, tasks)
1186 #define prev_task(p)	list_entry((p)->tasks.prev, struct task_struct, tasks)
1187 
1188 #define for_each_process(p) \
1189 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
1190 
1191 /*
1192  * Careful: do_each_thread/while_each_thread is a double loop so
1193  *          'break' will not work as expected - use goto instead.
1194  */
1195 #define do_each_thread(g, t) \
1196 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
1197 
1198 #define while_each_thread(g, t) \
1199 	while ((t = next_thread(t)) != g)
1200 
1201 extern task_t * FASTCALL(next_thread(const task_t *p));
1202 
1203 #define thread_group_leader(p)	(p->pid == p->tgid)
1204 
1205 static inline int thread_group_empty(task_t *p)
1206 {
1207 	return list_empty(&p->pids[PIDTYPE_TGID].pid_list);
1208 }
1209 
1210 #define delay_group_leader(p) \
1211 		(thread_group_leader(p) && !thread_group_empty(p))
1212 
1213 extern void unhash_process(struct task_struct *p);
1214 
1215 /*
1216  * Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring
1217  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
1218  * pins the final release of task.io_context.  Also protects ->cpuset.
1219  *
1220  * Nests both inside and outside of read_lock(&tasklist_lock).
1221  * It must not be nested with write_lock_irq(&tasklist_lock),
1222  * neither inside nor outside.
1223  */
1224 static inline void task_lock(struct task_struct *p)
1225 {
1226 	spin_lock(&p->alloc_lock);
1227 }
1228 
1229 static inline void task_unlock(struct task_struct *p)
1230 {
1231 	spin_unlock(&p->alloc_lock);
1232 }
1233 
1234 #ifndef __HAVE_THREAD_FUNCTIONS
1235 
1236 #define task_thread_info(task) (task)->thread_info
1237 
1238 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
1239 {
1240 	*task_thread_info(p) = *task_thread_info(org);
1241 	task_thread_info(p)->task = p;
1242 }
1243 
1244 static inline unsigned long *end_of_stack(struct task_struct *p)
1245 {
1246 	return (unsigned long *)(p->thread_info + 1);
1247 }
1248 
1249 #endif
1250 
1251 /* set thread flags in other task's structures
1252  * - see asm/thread_info.h for TIF_xxxx flags available
1253  */
1254 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1255 {
1256 	set_ti_thread_flag(task_thread_info(tsk), flag);
1257 }
1258 
1259 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1260 {
1261 	clear_ti_thread_flag(task_thread_info(tsk), flag);
1262 }
1263 
1264 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1265 {
1266 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1267 }
1268 
1269 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1270 {
1271 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1272 }
1273 
1274 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1275 {
1276 	return test_ti_thread_flag(task_thread_info(tsk), flag);
1277 }
1278 
1279 static inline void set_tsk_need_resched(struct task_struct *tsk)
1280 {
1281 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1282 }
1283 
1284 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1285 {
1286 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1287 }
1288 
1289 static inline int signal_pending(struct task_struct *p)
1290 {
1291 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
1292 }
1293 
1294 static inline int need_resched(void)
1295 {
1296 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
1297 }
1298 
1299 /*
1300  * cond_resched() and cond_resched_lock(): latency reduction via
1301  * explicit rescheduling in places that are safe. The return
1302  * value indicates whether a reschedule was done in fact.
1303  * cond_resched_lock() will drop the spinlock before scheduling,
1304  * cond_resched_softirq() will enable bhs before scheduling.
1305  */
1306 extern int cond_resched(void);
1307 extern int cond_resched_lock(spinlock_t * lock);
1308 extern int cond_resched_softirq(void);
1309 
1310 /*
1311  * Does a critical section need to be broken due to another
1312  * task waiting?:
1313  */
1314 #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
1315 # define need_lockbreak(lock) ((lock)->break_lock)
1316 #else
1317 # define need_lockbreak(lock) 0
1318 #endif
1319 
1320 /*
1321  * Does a critical section need to be broken due to another
1322  * task waiting or preemption being signalled:
1323  */
1324 static inline int lock_need_resched(spinlock_t *lock)
1325 {
1326 	if (need_lockbreak(lock) || need_resched())
1327 		return 1;
1328 	return 0;
1329 }
1330 
1331 /* Reevaluate whether the task has signals pending delivery.
1332    This is required every time the blocked sigset_t changes.
1333    callers must hold sighand->siglock.  */
1334 
1335 extern FASTCALL(void recalc_sigpending_tsk(struct task_struct *t));
1336 extern void recalc_sigpending(void);
1337 
1338 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
1339 
1340 /*
1341  * Wrappers for p->thread_info->cpu access. No-op on UP.
1342  */
1343 #ifdef CONFIG_SMP
1344 
1345 static inline unsigned int task_cpu(const struct task_struct *p)
1346 {
1347 	return task_thread_info(p)->cpu;
1348 }
1349 
1350 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1351 {
1352 	task_thread_info(p)->cpu = cpu;
1353 }
1354 
1355 #else
1356 
1357 static inline unsigned int task_cpu(const struct task_struct *p)
1358 {
1359 	return 0;
1360 }
1361 
1362 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1363 {
1364 }
1365 
1366 #endif /* CONFIG_SMP */
1367 
1368 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1369 extern void arch_pick_mmap_layout(struct mm_struct *mm);
1370 #else
1371 static inline void arch_pick_mmap_layout(struct mm_struct *mm)
1372 {
1373 	mm->mmap_base = TASK_UNMAPPED_BASE;
1374 	mm->get_unmapped_area = arch_get_unmapped_area;
1375 	mm->unmap_area = arch_unmap_area;
1376 }
1377 #endif
1378 
1379 extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
1380 extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
1381 
1382 #ifdef CONFIG_MAGIC_SYSRQ
1383 
1384 extern void normalize_rt_tasks(void);
1385 
1386 #endif
1387 
1388 #ifdef CONFIG_PM
1389 /*
1390  * Check if a process has been frozen
1391  */
1392 static inline int frozen(struct task_struct *p)
1393 {
1394 	return p->flags & PF_FROZEN;
1395 }
1396 
1397 /*
1398  * Check if there is a request to freeze a process
1399  */
1400 static inline int freezing(struct task_struct *p)
1401 {
1402 	return p->flags & PF_FREEZE;
1403 }
1404 
1405 /*
1406  * Request that a process be frozen
1407  * FIXME: SMP problem. We may not modify other process' flags!
1408  */
1409 static inline void freeze(struct task_struct *p)
1410 {
1411 	p->flags |= PF_FREEZE;
1412 }
1413 
1414 /*
1415  * Wake up a frozen process
1416  */
1417 static inline int thaw_process(struct task_struct *p)
1418 {
1419 	if (frozen(p)) {
1420 		p->flags &= ~PF_FROZEN;
1421 		wake_up_process(p);
1422 		return 1;
1423 	}
1424 	return 0;
1425 }
1426 
1427 /*
1428  * freezing is complete, mark process as frozen
1429  */
1430 static inline void frozen_process(struct task_struct *p)
1431 {
1432 	p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
1433 }
1434 
1435 extern void refrigerator(void);
1436 extern int freeze_processes(void);
1437 extern void thaw_processes(void);
1438 
1439 static inline int try_to_freeze(void)
1440 {
1441 	if (freezing(current)) {
1442 		refrigerator();
1443 		return 1;
1444 	} else
1445 		return 0;
1446 }
1447 #else
1448 static inline int frozen(struct task_struct *p) { return 0; }
1449 static inline int freezing(struct task_struct *p) { return 0; }
1450 static inline void freeze(struct task_struct *p) { BUG(); }
1451 static inline int thaw_process(struct task_struct *p) { return 1; }
1452 static inline void frozen_process(struct task_struct *p) { BUG(); }
1453 
1454 static inline void refrigerator(void) {}
1455 static inline int freeze_processes(void) { BUG(); return 0; }
1456 static inline void thaw_processes(void) {}
1457 
1458 static inline int try_to_freeze(void) { return 0; }
1459 
1460 #endif /* CONFIG_PM */
1461 #endif /* __KERNEL__ */
1462 
1463 #endif
1464