xref: /linux/include/linux/sched.h (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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 struct exec_domain;
39 
40 /*
41  * cloning flags:
42  */
43 #define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
44 #define CLONE_VM	0x00000100	/* set if VM shared between processes */
45 #define CLONE_FS	0x00000200	/* set if fs info shared between processes */
46 #define CLONE_FILES	0x00000400	/* set if open files shared between processes */
47 #define CLONE_SIGHAND	0x00000800	/* set if signal handlers and blocked signals shared */
48 #define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
49 #define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */
50 #define CLONE_PARENT	0x00008000	/* set if we want to have the same parent as the cloner */
51 #define CLONE_THREAD	0x00010000	/* Same thread group? */
52 #define CLONE_NEWNS	0x00020000	/* New namespace group? */
53 #define CLONE_SYSVSEM	0x00040000	/* share system V SEM_UNDO semantics */
54 #define CLONE_SETTLS	0x00080000	/* create a new TLS for the child */
55 #define CLONE_PARENT_SETTID	0x00100000	/* set the TID in the parent */
56 #define CLONE_CHILD_CLEARTID	0x00200000	/* clear the TID in the child */
57 #define CLONE_DETACHED		0x00400000	/* Unused, ignored */
58 #define CLONE_UNTRACED		0x00800000	/* set if the tracing process can't force CLONE_PTRACE on this clone */
59 #define CLONE_CHILD_SETTID	0x01000000	/* set the TID in the child */
60 #define CLONE_STOPPED		0x02000000	/* Start in stopped state */
61 
62 /*
63  * List of flags we want to share for kernel threads,
64  * if only because they are not used by them anyway.
65  */
66 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
67 
68 /*
69  * These are the constant used to fake the fixed-point load-average
70  * counting. Some notes:
71  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
72  *    a load-average precision of 10 bits integer + 11 bits fractional
73  *  - if you want to count load-averages more often, you need more
74  *    precision, or rounding will get you. With 2-second counting freq,
75  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
76  *    11 bit fractions.
77  */
78 extern unsigned long avenrun[];		/* Load averages */
79 
80 #define FSHIFT		11		/* nr of bits of precision */
81 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
82 #define LOAD_FREQ	(5*HZ)		/* 5 sec intervals */
83 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
84 #define EXP_5		2014		/* 1/exp(5sec/5min) */
85 #define EXP_15		2037		/* 1/exp(5sec/15min) */
86 
87 #define CALC_LOAD(load,exp,n) \
88 	load *= exp; \
89 	load += n*(FIXED_1-exp); \
90 	load >>= FSHIFT;
91 
92 extern unsigned long total_forks;
93 extern int nr_threads;
94 extern int last_pid;
95 DECLARE_PER_CPU(unsigned long, process_counts);
96 extern int nr_processes(void);
97 extern unsigned long nr_running(void);
98 extern unsigned long nr_uninterruptible(void);
99 extern unsigned long nr_iowait(void);
100 
101 #include <linux/time.h>
102 #include <linux/param.h>
103 #include <linux/resource.h>
104 #include <linux/timer.h>
105 
106 #include <asm/processor.h>
107 
108 #define TASK_RUNNING		0
109 #define TASK_INTERRUPTIBLE	1
110 #define TASK_UNINTERRUPTIBLE	2
111 #define TASK_STOPPED		4
112 #define TASK_TRACED		8
113 #define EXIT_ZOMBIE		16
114 #define EXIT_DEAD		32
115 
116 #define __set_task_state(tsk, state_value)		\
117 	do { (tsk)->state = (state_value); } while (0)
118 #define set_task_state(tsk, state_value)		\
119 	set_mb((tsk)->state, (state_value))
120 
121 #define __set_current_state(state_value)			\
122 	do { current->state = (state_value); } while (0)
123 #define set_current_state(state_value)		\
124 	set_mb(current->state, (state_value))
125 
126 /* Task command name length */
127 #define TASK_COMM_LEN 16
128 
129 /*
130  * Scheduling policies
131  */
132 #define SCHED_NORMAL		0
133 #define SCHED_FIFO		1
134 #define SCHED_RR		2
135 
136 struct sched_param {
137 	int sched_priority;
138 };
139 
140 #ifdef __KERNEL__
141 
142 #include <linux/spinlock.h>
143 
144 /*
145  * This serializes "schedule()" and also protects
146  * the run-queue from deletions/modifications (but
147  * _adding_ to the beginning of the run-queue has
148  * a separate lock).
149  */
150 extern rwlock_t tasklist_lock;
151 extern spinlock_t mmlist_lock;
152 
153 typedef struct task_struct task_t;
154 
155 extern void sched_init(void);
156 extern void sched_init_smp(void);
157 extern void init_idle(task_t *idle, int cpu);
158 
159 extern cpumask_t nohz_cpu_mask;
160 
161 extern void show_state(void);
162 extern void show_regs(struct pt_regs *);
163 
164 /*
165  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
166  * task), SP is the stack pointer of the first frame that should be shown in the back
167  * trace (or NULL if the entire call-chain of the task should be shown).
168  */
169 extern void show_stack(struct task_struct *task, unsigned long *sp);
170 
171 void io_schedule(void);
172 long io_schedule_timeout(long timeout);
173 
174 extern void cpu_init (void);
175 extern void trap_init(void);
176 extern void update_process_times(int user);
177 extern void scheduler_tick(void);
178 
179 /* Attach to any functions which should be ignored in wchan output. */
180 #define __sched		__attribute__((__section__(".sched.text")))
181 /* Is this address in the __sched functions? */
182 extern int in_sched_functions(unsigned long addr);
183 
184 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
185 extern signed long FASTCALL(schedule_timeout(signed long timeout));
186 asmlinkage void schedule(void);
187 
188 struct namespace;
189 
190 /* Maximum number of active map areas.. This is a random (large) number */
191 #define DEFAULT_MAX_MAP_COUNT	65536
192 
193 extern int sysctl_max_map_count;
194 
195 #include <linux/aio.h>
196 
197 extern unsigned long
198 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
199 		       unsigned long, unsigned long);
200 extern unsigned long
201 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
202 			  unsigned long len, unsigned long pgoff,
203 			  unsigned long flags);
204 extern void arch_unmap_area(struct mm_struct *, unsigned long);
205 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
206 
207 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
208 #define get_mm_counter(mm, member) ((mm)->_##member)
209 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
210 #define inc_mm_counter(mm, member) (mm)->_##member++
211 #define dec_mm_counter(mm, member) (mm)->_##member--
212 typedef unsigned long mm_counter_t;
213 
214 struct mm_struct {
215 	struct vm_area_struct * mmap;		/* list of VMAs */
216 	struct rb_root mm_rb;
217 	struct vm_area_struct * mmap_cache;	/* last find_vma result */
218 	unsigned long (*get_unmapped_area) (struct file *filp,
219 				unsigned long addr, unsigned long len,
220 				unsigned long pgoff, unsigned long flags);
221 	void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
222         unsigned long mmap_base;		/* base of mmap area */
223         unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
224 	unsigned long free_area_cache;		/* first hole of size cached_hole_size or larger */
225 	pgd_t * pgd;
226 	atomic_t mm_users;			/* How many users with user space? */
227 	atomic_t mm_count;			/* How many references to "struct mm_struct" (users count as 1) */
228 	int map_count;				/* number of VMAs */
229 	struct rw_semaphore mmap_sem;
230 	spinlock_t page_table_lock;		/* Protects page tables and some counters */
231 
232 	struct list_head mmlist;		/* List of maybe swapped mm's.  These are globally strung
233 						 * together off init_mm.mmlist, and are protected
234 						 * by mmlist_lock
235 						 */
236 
237 	unsigned long start_code, end_code, start_data, end_data;
238 	unsigned long start_brk, brk, start_stack;
239 	unsigned long arg_start, arg_end, env_start, env_end;
240 	unsigned long total_vm, locked_vm, shared_vm;
241 	unsigned long exec_vm, stack_vm, reserved_vm, def_flags, nr_ptes;
242 
243 	/* Special counters protected by the page_table_lock */
244 	mm_counter_t _rss;
245 	mm_counter_t _anon_rss;
246 
247 	unsigned long saved_auxv[42]; /* for /proc/PID/auxv */
248 
249 	unsigned dumpable:2;
250 	cpumask_t cpu_vm_mask;
251 
252 	/* Architecture-specific MM context */
253 	mm_context_t context;
254 
255 	/* Token based thrashing protection. */
256 	unsigned long swap_token_time;
257 	char recent_pagein;
258 
259 	/* coredumping support */
260 	int core_waiters;
261 	struct completion *core_startup_done, core_done;
262 
263 	/* aio bits */
264 	rwlock_t		ioctx_list_lock;
265 	struct kioctx		*ioctx_list;
266 
267 	struct kioctx		default_kioctx;
268 
269 	unsigned long hiwater_rss;	/* High-water RSS usage */
270 	unsigned long hiwater_vm;	/* High-water virtual memory usage */
271 };
272 
273 struct sighand_struct {
274 	atomic_t		count;
275 	struct k_sigaction	action[_NSIG];
276 	spinlock_t		siglock;
277 };
278 
279 /*
280  * NOTE! "signal_struct" does not have it's own
281  * locking, because a shared signal_struct always
282  * implies a shared sighand_struct, so locking
283  * sighand_struct is always a proper superset of
284  * the locking of signal_struct.
285  */
286 struct signal_struct {
287 	atomic_t		count;
288 	atomic_t		live;
289 
290 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
291 
292 	/* current thread group signal load-balancing target: */
293 	task_t			*curr_target;
294 
295 	/* shared signal handling: */
296 	struct sigpending	shared_pending;
297 
298 	/* thread group exit support */
299 	int			group_exit_code;
300 	/* overloaded:
301 	 * - notify group_exit_task when ->count is equal to notify_count
302 	 * - everyone except group_exit_task is stopped during signal delivery
303 	 *   of fatal signals, group_exit_task processes the signal.
304 	 */
305 	struct task_struct	*group_exit_task;
306 	int			notify_count;
307 
308 	/* thread group stop support, overloads group_exit_code too */
309 	int			group_stop_count;
310 	unsigned int		flags; /* see SIGNAL_* flags below */
311 
312 	/* POSIX.1b Interval Timers */
313 	struct list_head posix_timers;
314 
315 	/* ITIMER_REAL timer for the process */
316 	struct timer_list real_timer;
317 	unsigned long it_real_value, it_real_incr;
318 
319 	/* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
320 	cputime_t it_prof_expires, it_virt_expires;
321 	cputime_t it_prof_incr, it_virt_incr;
322 
323 	/* job control IDs */
324 	pid_t pgrp;
325 	pid_t tty_old_pgrp;
326 	pid_t session;
327 	/* boolean value for session group leader */
328 	int leader;
329 
330 	struct tty_struct *tty; /* NULL if no tty */
331 
332 	/*
333 	 * Cumulative resource counters for dead threads in the group,
334 	 * and for reaped dead child processes forked by this group.
335 	 * Live threads maintain their own counters and add to these
336 	 * in __exit_signal, except for the group leader.
337 	 */
338 	cputime_t utime, stime, cutime, cstime;
339 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
340 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
341 
342 	/*
343 	 * Cumulative ns of scheduled CPU time for dead threads in the
344 	 * group, not including a zombie group leader.  (This only differs
345 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
346 	 * other than jiffies.)
347 	 */
348 	unsigned long long sched_time;
349 
350 	/*
351 	 * We don't bother to synchronize most readers of this at all,
352 	 * because there is no reader checking a limit that actually needs
353 	 * to get both rlim_cur and rlim_max atomically, and either one
354 	 * alone is a single word that can safely be read normally.
355 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
356 	 * protect this instead of the siglock, because they really
357 	 * have no need to disable irqs.
358 	 */
359 	struct rlimit rlim[RLIM_NLIMITS];
360 
361 	struct list_head cpu_timers[3];
362 
363 	/* keep the process-shared keyrings here so that they do the right
364 	 * thing in threads created with CLONE_THREAD */
365 #ifdef CONFIG_KEYS
366 	struct key *session_keyring;	/* keyring inherited over fork */
367 	struct key *process_keyring;	/* keyring private to this process */
368 #endif
369 };
370 
371 /* Context switch must be unlocked if interrupts are to be enabled */
372 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
373 # define __ARCH_WANT_UNLOCKED_CTXSW
374 #endif
375 
376 /*
377  * Bits in flags field of signal_struct.
378  */
379 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
380 #define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
381 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
382 #define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
383 
384 
385 /*
386  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
387  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL tasks are
388  * in the range MAX_RT_PRIO..MAX_PRIO-1. Priority values
389  * are inverted: lower p->prio value means higher priority.
390  *
391  * The MAX_USER_RT_PRIO value allows the actual maximum
392  * RT priority to be separate from the value exported to
393  * user-space.  This allows kernel threads to set their
394  * priority to a value higher than any user task. Note:
395  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
396  */
397 
398 #define MAX_USER_RT_PRIO	100
399 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
400 
401 #define MAX_PRIO		(MAX_RT_PRIO + 40)
402 
403 #define rt_task(p)		(unlikely((p)->prio < MAX_RT_PRIO))
404 
405 /*
406  * Some day this will be a full-fledged user tracking system..
407  */
408 struct user_struct {
409 	atomic_t __count;	/* reference count */
410 	atomic_t processes;	/* How many processes does this user have? */
411 	atomic_t files;		/* How many open files does this user have? */
412 	atomic_t sigpending;	/* How many pending signals does this user have? */
413 	/* protected by mq_lock	*/
414 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
415 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
416 
417 #ifdef CONFIG_KEYS
418 	struct key *uid_keyring;	/* UID specific keyring */
419 	struct key *session_keyring;	/* UID's default session keyring */
420 #endif
421 
422 	/* Hash table maintenance information */
423 	struct list_head uidhash_list;
424 	uid_t uid;
425 };
426 
427 extern struct user_struct *find_user(uid_t);
428 
429 extern struct user_struct root_user;
430 #define INIT_USER (&root_user)
431 
432 typedef struct prio_array prio_array_t;
433 struct backing_dev_info;
434 struct reclaim_state;
435 
436 #ifdef CONFIG_SCHEDSTATS
437 struct sched_info {
438 	/* cumulative counters */
439 	unsigned long	cpu_time,	/* time spent on the cpu */
440 			run_delay,	/* time spent waiting on a runqueue */
441 			pcnt;		/* # of timeslices run on this cpu */
442 
443 	/* timestamps */
444 	unsigned long	last_arrival,	/* when we last ran on a cpu */
445 			last_queued;	/* when we were last queued to run */
446 };
447 
448 extern struct file_operations proc_schedstat_operations;
449 #endif
450 
451 enum idle_type
452 {
453 	SCHED_IDLE,
454 	NOT_IDLE,
455 	NEWLY_IDLE,
456 	MAX_IDLE_TYPES
457 };
458 
459 /*
460  * sched-domains (multiprocessor balancing) declarations:
461  */
462 #ifdef CONFIG_SMP
463 #define SCHED_LOAD_SCALE	128UL	/* increase resolution of load */
464 
465 #define SD_LOAD_BALANCE		1	/* Do load balancing on this domain. */
466 #define SD_BALANCE_NEWIDLE	2	/* Balance when about to become idle */
467 #define SD_BALANCE_EXEC		4	/* Balance on exec */
468 #define SD_BALANCE_FORK		8	/* Balance on fork, clone */
469 #define SD_WAKE_IDLE		16	/* Wake to idle CPU on task wakeup */
470 #define SD_WAKE_AFFINE		32	/* Wake task to waking CPU */
471 #define SD_WAKE_BALANCE		64	/* Perform balancing at task wakeup */
472 #define SD_SHARE_CPUPOWER	128	/* Domain members share cpu power */
473 
474 struct sched_group {
475 	struct sched_group *next;	/* Must be a circular list */
476 	cpumask_t cpumask;
477 
478 	/*
479 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
480 	 * single CPU. This is read only (except for setup, hotplug CPU).
481 	 */
482 	unsigned long cpu_power;
483 };
484 
485 struct sched_domain {
486 	/* These fields must be setup */
487 	struct sched_domain *parent;	/* top domain must be null terminated */
488 	struct sched_group *groups;	/* the balancing groups of the domain */
489 	cpumask_t span;			/* span of all CPUs in this domain */
490 	unsigned long min_interval;	/* Minimum balance interval ms */
491 	unsigned long max_interval;	/* Maximum balance interval ms */
492 	unsigned int busy_factor;	/* less balancing by factor if busy */
493 	unsigned int imbalance_pct;	/* No balance until over watermark */
494 	unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
495 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
496 	unsigned int per_cpu_gain;	/* CPU % gained by adding domain cpus */
497 	unsigned int busy_idx;
498 	unsigned int idle_idx;
499 	unsigned int newidle_idx;
500 	unsigned int wake_idx;
501 	unsigned int forkexec_idx;
502 	int flags;			/* See SD_* */
503 
504 	/* Runtime fields. */
505 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
506 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
507 	unsigned int nr_balance_failed; /* initialise to 0 */
508 
509 #ifdef CONFIG_SCHEDSTATS
510 	/* load_balance() stats */
511 	unsigned long lb_cnt[MAX_IDLE_TYPES];
512 	unsigned long lb_failed[MAX_IDLE_TYPES];
513 	unsigned long lb_balanced[MAX_IDLE_TYPES];
514 	unsigned long lb_imbalance[MAX_IDLE_TYPES];
515 	unsigned long lb_gained[MAX_IDLE_TYPES];
516 	unsigned long lb_hot_gained[MAX_IDLE_TYPES];
517 	unsigned long lb_nobusyg[MAX_IDLE_TYPES];
518 	unsigned long lb_nobusyq[MAX_IDLE_TYPES];
519 
520 	/* Active load balancing */
521 	unsigned long alb_cnt;
522 	unsigned long alb_failed;
523 	unsigned long alb_pushed;
524 
525 	/* SD_BALANCE_EXEC stats */
526 	unsigned long sbe_cnt;
527 	unsigned long sbe_balanced;
528 	unsigned long sbe_pushed;
529 
530 	/* SD_BALANCE_FORK stats */
531 	unsigned long sbf_cnt;
532 	unsigned long sbf_balanced;
533 	unsigned long sbf_pushed;
534 
535 	/* try_to_wake_up() stats */
536 	unsigned long ttwu_wake_remote;
537 	unsigned long ttwu_move_affine;
538 	unsigned long ttwu_move_balance;
539 #endif
540 };
541 
542 extern void partition_sched_domains(cpumask_t *partition1,
543 				    cpumask_t *partition2);
544 #ifdef ARCH_HAS_SCHED_DOMAIN
545 /* Useful helpers that arch setup code may use. Defined in kernel/sched.c */
546 extern cpumask_t cpu_isolated_map;
547 extern void init_sched_build_groups(struct sched_group groups[],
548 	                        cpumask_t span, int (*group_fn)(int cpu));
549 extern void cpu_attach_domain(struct sched_domain *sd, int cpu);
550 #endif /* ARCH_HAS_SCHED_DOMAIN */
551 #endif /* CONFIG_SMP */
552 
553 
554 struct io_context;			/* See blkdev.h */
555 void exit_io_context(void);
556 struct cpuset;
557 
558 #define NGROUPS_SMALL		32
559 #define NGROUPS_PER_BLOCK	((int)(PAGE_SIZE / sizeof(gid_t)))
560 struct group_info {
561 	int ngroups;
562 	atomic_t usage;
563 	gid_t small_block[NGROUPS_SMALL];
564 	int nblocks;
565 	gid_t *blocks[0];
566 };
567 
568 /*
569  * get_group_info() must be called with the owning task locked (via task_lock())
570  * when task != current.  The reason being that the vast majority of callers are
571  * looking at current->group_info, which can not be changed except by the
572  * current task.  Changing current->group_info requires the task lock, too.
573  */
574 #define get_group_info(group_info) do { \
575 	atomic_inc(&(group_info)->usage); \
576 } while (0)
577 
578 #define put_group_info(group_info) do { \
579 	if (atomic_dec_and_test(&(group_info)->usage)) \
580 		groups_free(group_info); \
581 } while (0)
582 
583 extern struct group_info *groups_alloc(int gidsetsize);
584 extern void groups_free(struct group_info *group_info);
585 extern int set_current_groups(struct group_info *group_info);
586 extern int groups_search(struct group_info *group_info, gid_t grp);
587 /* access the groups "array" with this macro */
588 #define GROUP_AT(gi, i) \
589     ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK])
590 
591 
592 struct audit_context;		/* See audit.c */
593 struct mempolicy;
594 
595 struct task_struct {
596 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
597 	struct thread_info *thread_info;
598 	atomic_t usage;
599 	unsigned long flags;	/* per process flags, defined below */
600 	unsigned long ptrace;
601 
602 	int lock_depth;		/* BKL lock depth */
603 
604 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
605 	int oncpu;
606 #endif
607 	int prio, static_prio;
608 	struct list_head run_list;
609 	prio_array_t *array;
610 
611 	unsigned short ioprio;
612 
613 	unsigned long sleep_avg;
614 	unsigned long long timestamp, last_ran;
615 	unsigned long long sched_time; /* sched_clock time spent running */
616 	int activated;
617 
618 	unsigned long policy;
619 	cpumask_t cpus_allowed;
620 	unsigned int time_slice, first_time_slice;
621 
622 #ifdef CONFIG_SCHEDSTATS
623 	struct sched_info sched_info;
624 #endif
625 
626 	struct list_head tasks;
627 	/*
628 	 * ptrace_list/ptrace_children forms the list of my children
629 	 * that were stolen by a ptracer.
630 	 */
631 	struct list_head ptrace_children;
632 	struct list_head ptrace_list;
633 
634 	struct mm_struct *mm, *active_mm;
635 
636 /* task state */
637 	struct linux_binfmt *binfmt;
638 	long exit_state;
639 	int exit_code, exit_signal;
640 	int pdeath_signal;  /*  The signal sent when the parent dies  */
641 	/* ??? */
642 	unsigned long personality;
643 	unsigned did_exec:1;
644 	pid_t pid;
645 	pid_t tgid;
646 	/*
647 	 * pointers to (original) parent process, youngest child, younger sibling,
648 	 * older sibling, respectively.  (p->father can be replaced with
649 	 * p->parent->pid)
650 	 */
651 	struct task_struct *real_parent; /* real parent process (when being debugged) */
652 	struct task_struct *parent;	/* parent process */
653 	/*
654 	 * children/sibling forms the list of my children plus the
655 	 * tasks I'm ptracing.
656 	 */
657 	struct list_head children;	/* list of my children */
658 	struct list_head sibling;	/* linkage in my parent's children list */
659 	struct task_struct *group_leader;	/* threadgroup leader */
660 
661 	/* PID/PID hash table linkage. */
662 	struct pid pids[PIDTYPE_MAX];
663 
664 	struct completion *vfork_done;		/* for vfork() */
665 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
666 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
667 
668 	unsigned long rt_priority;
669 	cputime_t utime, stime;
670 	unsigned long nvcsw, nivcsw; /* context switch counts */
671 	struct timespec start_time;
672 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
673 	unsigned long min_flt, maj_flt;
674 
675   	cputime_t it_prof_expires, it_virt_expires;
676 	unsigned long long it_sched_expires;
677 	struct list_head cpu_timers[3];
678 
679 /* process credentials */
680 	uid_t uid,euid,suid,fsuid;
681 	gid_t gid,egid,sgid,fsgid;
682 	struct group_info *group_info;
683 	kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
684 	unsigned keep_capabilities:1;
685 	struct user_struct *user;
686 #ifdef CONFIG_KEYS
687 	struct key *thread_keyring;	/* keyring private to this thread */
688 	unsigned char jit_keyring;	/* default keyring to attach requested keys to */
689 #endif
690 	int oomkilladj; /* OOM kill score adjustment (bit shift). */
691 	char comm[TASK_COMM_LEN]; /* executable name excluding path
692 				     - access with [gs]et_task_comm (which lock
693 				       it with task_lock())
694 				     - initialized normally by flush_old_exec */
695 /* file system info */
696 	int link_count, total_link_count;
697 /* ipc stuff */
698 	struct sysv_sem sysvsem;
699 /* CPU-specific state of this task */
700 	struct thread_struct thread;
701 /* filesystem information */
702 	struct fs_struct *fs;
703 /* open file information */
704 	struct files_struct *files;
705 /* namespace */
706 	struct namespace *namespace;
707 /* signal handlers */
708 	struct signal_struct *signal;
709 	struct sighand_struct *sighand;
710 
711 	sigset_t blocked, real_blocked;
712 	struct sigpending pending;
713 
714 	unsigned long sas_ss_sp;
715 	size_t sas_ss_size;
716 	int (*notifier)(void *priv);
717 	void *notifier_data;
718 	sigset_t *notifier_mask;
719 
720 	void *security;
721 	struct audit_context *audit_context;
722 	seccomp_t seccomp;
723 
724 /* Thread group tracking */
725    	u32 parent_exec_id;
726    	u32 self_exec_id;
727 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
728 	spinlock_t alloc_lock;
729 /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
730 	spinlock_t proc_lock;
731 
732 /* journalling filesystem info */
733 	void *journal_info;
734 
735 /* VM state */
736 	struct reclaim_state *reclaim_state;
737 
738 	struct dentry *proc_dentry;
739 	struct backing_dev_info *backing_dev_info;
740 
741 	struct io_context *io_context;
742 
743 	unsigned long ptrace_message;
744 	siginfo_t *last_siginfo; /* For ptrace use.  */
745 /*
746  * current io wait handle: wait queue entry to use for io waits
747  * If this thread is processing aio, this points at the waitqueue
748  * inside the currently handled kiocb. It may be NULL (i.e. default
749  * to a stack based synchronous wait) if its doing sync IO.
750  */
751 	wait_queue_t *io_wait;
752 /* i/o counters(bytes read/written, #syscalls */
753 	u64 rchar, wchar, syscr, syscw;
754 #if defined(CONFIG_BSD_PROCESS_ACCT)
755 	u64 acct_rss_mem1;	/* accumulated rss usage */
756 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
757 	clock_t acct_stimexpd;	/* clock_t-converted stime since last update */
758 #endif
759 #ifdef CONFIG_NUMA
760   	struct mempolicy *mempolicy;
761 	short il_next;
762 #endif
763 #ifdef CONFIG_CPUSETS
764 	struct cpuset *cpuset;
765 	nodemask_t mems_allowed;
766 	int cpuset_mems_generation;
767 #endif
768 	atomic_t fs_excl;	/* holding fs exclusive resources */
769 };
770 
771 static inline pid_t process_group(struct task_struct *tsk)
772 {
773 	return tsk->signal->pgrp;
774 }
775 
776 /**
777  * pid_alive - check that a task structure is not stale
778  * @p: Task structure to be checked.
779  *
780  * Test if a process is not yet dead (at most zombie state)
781  * If pid_alive fails, then pointers within the task structure
782  * can be stale and must not be dereferenced.
783  */
784 static inline int pid_alive(struct task_struct *p)
785 {
786 	return p->pids[PIDTYPE_PID].nr != 0;
787 }
788 
789 extern void free_task(struct task_struct *tsk);
790 extern void __put_task_struct(struct task_struct *tsk);
791 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
792 #define put_task_struct(tsk) \
793 do { if (atomic_dec_and_test(&(tsk)->usage)) __put_task_struct(tsk); } while(0)
794 
795 /*
796  * Per process flags
797  */
798 #define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
799 					/* Not implemented yet, only for 486*/
800 #define PF_STARTING	0x00000002	/* being created */
801 #define PF_EXITING	0x00000004	/* getting shut down */
802 #define PF_DEAD		0x00000008	/* Dead */
803 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
804 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
805 #define PF_DUMPCORE	0x00000200	/* dumped core */
806 #define PF_SIGNALED	0x00000400	/* killed by a signal */
807 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
808 #define PF_FLUSHER	0x00001000	/* responsible for disk writeback */
809 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
810 #define PF_FREEZE	0x00004000	/* this task is being frozen for suspend now */
811 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
812 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
813 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
814 #define PF_KSWAPD	0x00040000	/* I am kswapd */
815 #define PF_SWAPOFF	0x00080000	/* I am in swapoff */
816 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
817 #define PF_SYNCWRITE	0x00200000	/* I am doing a sync write */
818 #define PF_BORROWED_MM	0x00400000	/* I am a kthread doing use_mm */
819 #define PF_RANDOMIZE	0x00800000	/* randomize virtual address space */
820 
821 /*
822  * Only the _current_ task can read/write to tsk->flags, but other
823  * tasks can access tsk->flags in readonly mode for example
824  * with tsk_used_math (like during threaded core dumping).
825  * There is however an exception to this rule during ptrace
826  * or during fork: the ptracer task is allowed to write to the
827  * child->flags of its traced child (same goes for fork, the parent
828  * can write to the child->flags), because we're guaranteed the
829  * child is not running and in turn not changing child->flags
830  * at the same time the parent does it.
831  */
832 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
833 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
834 #define clear_used_math() clear_stopped_child_used_math(current)
835 #define set_used_math() set_stopped_child_used_math(current)
836 #define conditional_stopped_child_used_math(condition, child) \
837 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
838 #define conditional_used_math(condition) \
839 	conditional_stopped_child_used_math(condition, current)
840 #define copy_to_stopped_child_used_math(child) \
841 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
842 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
843 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
844 #define used_math() tsk_used_math(current)
845 
846 #ifdef CONFIG_SMP
847 extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
848 #else
849 static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)
850 {
851 	if (!cpus_intersects(new_mask, cpu_online_map))
852 		return -EINVAL;
853 	return 0;
854 }
855 #endif
856 
857 extern unsigned long long sched_clock(void);
858 extern unsigned long long current_sched_time(const task_t *current_task);
859 
860 /* sched_exec is called by processes performing an exec */
861 #ifdef CONFIG_SMP
862 extern void sched_exec(void);
863 #else
864 #define sched_exec()   {}
865 #endif
866 
867 #ifdef CONFIG_HOTPLUG_CPU
868 extern void idle_task_exit(void);
869 #else
870 static inline void idle_task_exit(void) {}
871 #endif
872 
873 extern void sched_idle_next(void);
874 extern void set_user_nice(task_t *p, long nice);
875 extern int task_prio(const task_t *p);
876 extern int task_nice(const task_t *p);
877 extern int can_nice(const task_t *p, const int nice);
878 extern int task_curr(const task_t *p);
879 extern int idle_cpu(int cpu);
880 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
881 extern task_t *idle_task(int cpu);
882 
883 void yield(void);
884 
885 /*
886  * The default (Linux) execution domain.
887  */
888 extern struct exec_domain	default_exec_domain;
889 
890 union thread_union {
891 	struct thread_info thread_info;
892 	unsigned long stack[THREAD_SIZE/sizeof(long)];
893 };
894 
895 #ifndef __HAVE_ARCH_KSTACK_END
896 static inline int kstack_end(void *addr)
897 {
898 	/* Reliable end of stack detection:
899 	 * Some APM bios versions misalign the stack
900 	 */
901 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
902 }
903 #endif
904 
905 extern union thread_union init_thread_union;
906 extern struct task_struct init_task;
907 
908 extern struct   mm_struct init_mm;
909 
910 #define find_task_by_pid(nr)	find_task_by_pid_type(PIDTYPE_PID, nr)
911 extern struct task_struct *find_task_by_pid_type(int type, int pid);
912 extern void set_special_pids(pid_t session, pid_t pgrp);
913 extern void __set_special_pids(pid_t session, pid_t pgrp);
914 
915 /* per-UID process charging. */
916 extern struct user_struct * alloc_uid(uid_t);
917 static inline struct user_struct *get_uid(struct user_struct *u)
918 {
919 	atomic_inc(&u->__count);
920 	return u;
921 }
922 extern void free_uid(struct user_struct *);
923 extern void switch_uid(struct user_struct *);
924 
925 #include <asm/current.h>
926 
927 extern void do_timer(struct pt_regs *);
928 
929 extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
930 extern int FASTCALL(wake_up_process(struct task_struct * tsk));
931 extern void FASTCALL(wake_up_new_task(struct task_struct * tsk,
932 						unsigned long clone_flags));
933 #ifdef CONFIG_SMP
934  extern void kick_process(struct task_struct *tsk);
935 #else
936  static inline void kick_process(struct task_struct *tsk) { }
937 #endif
938 extern void FASTCALL(sched_fork(task_t * p, int clone_flags));
939 extern void FASTCALL(sched_exit(task_t * p));
940 
941 extern int in_group_p(gid_t);
942 extern int in_egroup_p(gid_t);
943 
944 extern void proc_caches_init(void);
945 extern void flush_signals(struct task_struct *);
946 extern void flush_signal_handlers(struct task_struct *, int force_default);
947 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
948 
949 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
950 {
951 	unsigned long flags;
952 	int ret;
953 
954 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
955 	ret = dequeue_signal(tsk, mask, info);
956 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
957 
958 	return ret;
959 }
960 
961 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
962 			      sigset_t *mask);
963 extern void unblock_all_signals(void);
964 extern void release_task(struct task_struct * p);
965 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
966 extern int send_group_sig_info(int, struct siginfo *, struct task_struct *);
967 extern int force_sigsegv(int, struct task_struct *);
968 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
969 extern int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp);
970 extern int kill_pg_info(int, struct siginfo *, pid_t);
971 extern int kill_proc_info(int, struct siginfo *, pid_t);
972 extern void do_notify_parent(struct task_struct *, int);
973 extern void force_sig(int, struct task_struct *);
974 extern void force_sig_specific(int, struct task_struct *);
975 extern int send_sig(int, struct task_struct *, int);
976 extern void zap_other_threads(struct task_struct *p);
977 extern int kill_pg(pid_t, int, int);
978 extern int kill_sl(pid_t, int, int);
979 extern int kill_proc(pid_t, int, int);
980 extern struct sigqueue *sigqueue_alloc(void);
981 extern void sigqueue_free(struct sigqueue *);
982 extern int send_sigqueue(int, struct sigqueue *,  struct task_struct *);
983 extern int send_group_sigqueue(int, struct sigqueue *,  struct task_struct *);
984 extern int do_sigaction(int, const struct k_sigaction *, struct k_sigaction *);
985 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
986 
987 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
988 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
989 #define SEND_SIG_PRIV	((struct siginfo *) 1)
990 #define SEND_SIG_FORCED	((struct siginfo *) 2)
991 
992 /* True if we are on the alternate signal stack.  */
993 
994 static inline int on_sig_stack(unsigned long sp)
995 {
996 	return (sp - current->sas_ss_sp < current->sas_ss_size);
997 }
998 
999 static inline int sas_ss_flags(unsigned long sp)
1000 {
1001 	return (current->sas_ss_size == 0 ? SS_DISABLE
1002 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
1003 }
1004 
1005 
1006 #ifdef CONFIG_SECURITY
1007 /* code is in security.c */
1008 extern int capable(int cap);
1009 #else
1010 static inline int capable(int cap)
1011 {
1012 	if (cap_raised(current->cap_effective, cap)) {
1013 		current->flags |= PF_SUPERPRIV;
1014 		return 1;
1015 	}
1016 	return 0;
1017 }
1018 #endif
1019 
1020 /*
1021  * Routines for handling mm_structs
1022  */
1023 extern struct mm_struct * mm_alloc(void);
1024 
1025 /* mmdrop drops the mm and the page tables */
1026 extern void FASTCALL(__mmdrop(struct mm_struct *));
1027 static inline void mmdrop(struct mm_struct * mm)
1028 {
1029 	if (atomic_dec_and_test(&mm->mm_count))
1030 		__mmdrop(mm);
1031 }
1032 
1033 /* mmput gets rid of the mappings and all user-space */
1034 extern void mmput(struct mm_struct *);
1035 /* Grab a reference to a task's mm, if it is not already going away */
1036 extern struct mm_struct *get_task_mm(struct task_struct *task);
1037 /* Remove the current tasks stale references to the old mm_struct */
1038 extern void mm_release(struct task_struct *, struct mm_struct *);
1039 
1040 extern int  copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
1041 extern void flush_thread(void);
1042 extern void exit_thread(void);
1043 
1044 extern void exit_files(struct task_struct *);
1045 extern void exit_signal(struct task_struct *);
1046 extern void __exit_signal(struct task_struct *);
1047 extern void exit_sighand(struct task_struct *);
1048 extern void __exit_sighand(struct task_struct *);
1049 extern void exit_itimers(struct signal_struct *);
1050 
1051 extern NORET_TYPE void do_group_exit(int);
1052 
1053 extern void daemonize(const char *, ...);
1054 extern int allow_signal(int);
1055 extern int disallow_signal(int);
1056 extern task_t *child_reaper;
1057 
1058 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1059 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
1060 task_t *fork_idle(int);
1061 
1062 extern void set_task_comm(struct task_struct *tsk, char *from);
1063 extern void get_task_comm(char *to, struct task_struct *tsk);
1064 
1065 #ifdef CONFIG_SMP
1066 extern void wait_task_inactive(task_t * p);
1067 #else
1068 #define wait_task_inactive(p)	do { } while (0)
1069 #endif
1070 
1071 #define remove_parent(p)	list_del_init(&(p)->sibling)
1072 #define add_parent(p, parent)	list_add_tail(&(p)->sibling,&(parent)->children)
1073 
1074 #define REMOVE_LINKS(p) do {					\
1075 	if (thread_group_leader(p))				\
1076 		list_del_init(&(p)->tasks);			\
1077 	remove_parent(p);					\
1078 	} while (0)
1079 
1080 #define SET_LINKS(p) do {					\
1081 	if (thread_group_leader(p))				\
1082 		list_add_tail(&(p)->tasks,&init_task.tasks);	\
1083 	add_parent(p, (p)->parent);				\
1084 	} while (0)
1085 
1086 #define next_task(p)	list_entry((p)->tasks.next, struct task_struct, tasks)
1087 #define prev_task(p)	list_entry((p)->tasks.prev, struct task_struct, tasks)
1088 
1089 #define for_each_process(p) \
1090 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
1091 
1092 /*
1093  * Careful: do_each_thread/while_each_thread is a double loop so
1094  *          'break' will not work as expected - use goto instead.
1095  */
1096 #define do_each_thread(g, t) \
1097 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
1098 
1099 #define while_each_thread(g, t) \
1100 	while ((t = next_thread(t)) != g)
1101 
1102 extern task_t * FASTCALL(next_thread(const task_t *p));
1103 
1104 #define thread_group_leader(p)	(p->pid == p->tgid)
1105 
1106 static inline int thread_group_empty(task_t *p)
1107 {
1108 	return list_empty(&p->pids[PIDTYPE_TGID].pid_list);
1109 }
1110 
1111 #define delay_group_leader(p) \
1112 		(thread_group_leader(p) && !thread_group_empty(p))
1113 
1114 extern void unhash_process(struct task_struct *p);
1115 
1116 /*
1117  * Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring
1118  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
1119  * pins the final release of task.io_context.
1120  *
1121  * Nests both inside and outside of read_lock(&tasklist_lock).
1122  * It must not be nested with write_lock_irq(&tasklist_lock),
1123  * neither inside nor outside.
1124  */
1125 static inline void task_lock(struct task_struct *p)
1126 {
1127 	spin_lock(&p->alloc_lock);
1128 }
1129 
1130 static inline void task_unlock(struct task_struct *p)
1131 {
1132 	spin_unlock(&p->alloc_lock);
1133 }
1134 
1135 /* set thread flags in other task's structures
1136  * - see asm/thread_info.h for TIF_xxxx flags available
1137  */
1138 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1139 {
1140 	set_ti_thread_flag(tsk->thread_info,flag);
1141 }
1142 
1143 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1144 {
1145 	clear_ti_thread_flag(tsk->thread_info,flag);
1146 }
1147 
1148 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1149 {
1150 	return test_and_set_ti_thread_flag(tsk->thread_info,flag);
1151 }
1152 
1153 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1154 {
1155 	return test_and_clear_ti_thread_flag(tsk->thread_info,flag);
1156 }
1157 
1158 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1159 {
1160 	return test_ti_thread_flag(tsk->thread_info,flag);
1161 }
1162 
1163 static inline void set_tsk_need_resched(struct task_struct *tsk)
1164 {
1165 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1166 }
1167 
1168 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1169 {
1170 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1171 }
1172 
1173 static inline int signal_pending(struct task_struct *p)
1174 {
1175 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
1176 }
1177 
1178 static inline int need_resched(void)
1179 {
1180 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
1181 }
1182 
1183 /*
1184  * cond_resched() and cond_resched_lock(): latency reduction via
1185  * explicit rescheduling in places that are safe. The return
1186  * value indicates whether a reschedule was done in fact.
1187  * cond_resched_lock() will drop the spinlock before scheduling,
1188  * cond_resched_softirq() will enable bhs before scheduling.
1189  */
1190 extern int cond_resched(void);
1191 extern int cond_resched_lock(spinlock_t * lock);
1192 extern int cond_resched_softirq(void);
1193 
1194 /*
1195  * Does a critical section need to be broken due to another
1196  * task waiting?:
1197  */
1198 #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
1199 # define need_lockbreak(lock) ((lock)->break_lock)
1200 #else
1201 # define need_lockbreak(lock) 0
1202 #endif
1203 
1204 /*
1205  * Does a critical section need to be broken due to another
1206  * task waiting or preemption being signalled:
1207  */
1208 static inline int lock_need_resched(spinlock_t *lock)
1209 {
1210 	if (need_lockbreak(lock) || need_resched())
1211 		return 1;
1212 	return 0;
1213 }
1214 
1215 /* Reevaluate whether the task has signals pending delivery.
1216    This is required every time the blocked sigset_t changes.
1217    callers must hold sighand->siglock.  */
1218 
1219 extern FASTCALL(void recalc_sigpending_tsk(struct task_struct *t));
1220 extern void recalc_sigpending(void);
1221 
1222 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
1223 
1224 /*
1225  * Wrappers for p->thread_info->cpu access. No-op on UP.
1226  */
1227 #ifdef CONFIG_SMP
1228 
1229 static inline unsigned int task_cpu(const struct task_struct *p)
1230 {
1231 	return p->thread_info->cpu;
1232 }
1233 
1234 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1235 {
1236 	p->thread_info->cpu = cpu;
1237 }
1238 
1239 #else
1240 
1241 static inline unsigned int task_cpu(const struct task_struct *p)
1242 {
1243 	return 0;
1244 }
1245 
1246 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1247 {
1248 }
1249 
1250 #endif /* CONFIG_SMP */
1251 
1252 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1253 extern void arch_pick_mmap_layout(struct mm_struct *mm);
1254 #else
1255 static inline void arch_pick_mmap_layout(struct mm_struct *mm)
1256 {
1257 	mm->mmap_base = TASK_UNMAPPED_BASE;
1258 	mm->get_unmapped_area = arch_get_unmapped_area;
1259 	mm->unmap_area = arch_unmap_area;
1260 }
1261 #endif
1262 
1263 extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
1264 extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
1265 
1266 #ifdef CONFIG_MAGIC_SYSRQ
1267 
1268 extern void normalize_rt_tasks(void);
1269 
1270 #endif
1271 
1272 #ifdef CONFIG_PM
1273 /*
1274  * Check if a process has been frozen
1275  */
1276 static inline int frozen(struct task_struct *p)
1277 {
1278 	return p->flags & PF_FROZEN;
1279 }
1280 
1281 /*
1282  * Check if there is a request to freeze a process
1283  */
1284 static inline int freezing(struct task_struct *p)
1285 {
1286 	return p->flags & PF_FREEZE;
1287 }
1288 
1289 /*
1290  * Request that a process be frozen
1291  * FIXME: SMP problem. We may not modify other process' flags!
1292  */
1293 static inline void freeze(struct task_struct *p)
1294 {
1295 	p->flags |= PF_FREEZE;
1296 }
1297 
1298 /*
1299  * Wake up a frozen process
1300  */
1301 static inline int thaw_process(struct task_struct *p)
1302 {
1303 	if (frozen(p)) {
1304 		p->flags &= ~PF_FROZEN;
1305 		wake_up_process(p);
1306 		return 1;
1307 	}
1308 	return 0;
1309 }
1310 
1311 /*
1312  * freezing is complete, mark process as frozen
1313  */
1314 static inline void frozen_process(struct task_struct *p)
1315 {
1316 	p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
1317 }
1318 
1319 extern void refrigerator(void);
1320 extern int freeze_processes(void);
1321 extern void thaw_processes(void);
1322 
1323 static inline int try_to_freeze(void)
1324 {
1325 	if (freezing(current)) {
1326 		refrigerator();
1327 		return 1;
1328 	} else
1329 		return 0;
1330 }
1331 #else
1332 static inline int frozen(struct task_struct *p) { return 0; }
1333 static inline int freezing(struct task_struct *p) { return 0; }
1334 static inline void freeze(struct task_struct *p) { BUG(); }
1335 static inline int thaw_process(struct task_struct *p) { return 1; }
1336 static inline void frozen_process(struct task_struct *p) { BUG(); }
1337 
1338 static inline void refrigerator(void) {}
1339 static inline int freeze_processes(void) { BUG(); return 0; }
1340 static inline void thaw_processes(void) {}
1341 
1342 static inline int try_to_freeze(void) { return 0; }
1343 
1344 #endif /* CONFIG_PM */
1345 #endif /* __KERNEL__ */
1346 
1347 #endif
1348