[PATCH] Block queue IO tracing support (blktrace) as of 2006-03-23
[deliverable/linux.git] / include / linux / sched.h
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 #include <linux/rcupdate.h>
38
39 #include <linux/auxvec.h> /* For AT_VECTOR_SIZE */
40
41 struct exec_domain;
42
43 /*
44 * cloning flags:
45 */
46 #define CSIGNAL 0x000000ff /* signal mask to be sent at exit */
47 #define CLONE_VM 0x00000100 /* set if VM shared between processes */
48 #define CLONE_FS 0x00000200 /* set if fs info shared between processes */
49 #define CLONE_FILES 0x00000400 /* set if open files shared between processes */
50 #define CLONE_SIGHAND 0x00000800 /* set if signal handlers and blocked signals shared */
51 #define CLONE_PTRACE 0x00002000 /* set if we want to let tracing continue on the child too */
52 #define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */
53 #define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */
54 #define CLONE_THREAD 0x00010000 /* Same thread group? */
55 #define CLONE_NEWNS 0x00020000 /* New namespace group? */
56 #define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */
57 #define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */
58 #define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */
59 #define CLONE_CHILD_CLEARTID 0x00200000 /* clear the TID in the child */
60 #define CLONE_DETACHED 0x00400000 /* Unused, ignored */
61 #define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */
62 #define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
63 #define CLONE_STOPPED 0x02000000 /* Start in stopped state */
64
65 /*
66 * List of flags we want to share for kernel threads,
67 * if only because they are not used by them anyway.
68 */
69 #define CLONE_KERNEL (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
70
71 /*
72 * These are the constant used to fake the fixed-point load-average
73 * counting. Some notes:
74 * - 11 bit fractions expand to 22 bits by the multiplies: this gives
75 * a load-average precision of 10 bits integer + 11 bits fractional
76 * - if you want to count load-averages more often, you need more
77 * precision, or rounding will get you. With 2-second counting freq,
78 * the EXP_n values would be 1981, 2034 and 2043 if still using only
79 * 11 bit fractions.
80 */
81 extern unsigned long avenrun[]; /* Load averages */
82
83 #define FSHIFT 11 /* nr of bits of precision */
84 #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
85 #define LOAD_FREQ (5*HZ) /* 5 sec intervals */
86 #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
87 #define EXP_5 2014 /* 1/exp(5sec/5min) */
88 #define EXP_15 2037 /* 1/exp(5sec/15min) */
89
90 #define CALC_LOAD(load,exp,n) \
91 load *= exp; \
92 load += n*(FIXED_1-exp); \
93 load >>= FSHIFT;
94
95 extern unsigned long total_forks;
96 extern int nr_threads;
97 extern int last_pid;
98 DECLARE_PER_CPU(unsigned long, process_counts);
99 extern int nr_processes(void);
100 extern unsigned long nr_running(void);
101 extern unsigned long nr_uninterruptible(void);
102 extern unsigned long nr_iowait(void);
103
104 #include <linux/time.h>
105 #include <linux/param.h>
106 #include <linux/resource.h>
107 #include <linux/timer.h>
108 #include <linux/hrtimer.h>
109
110 #include <asm/processor.h>
111
112 /*
113 * Task state bitmask. NOTE! These bits are also
114 * encoded in fs/proc/array.c: get_task_state().
115 *
116 * We have two separate sets of flags: task->state
117 * is about runnability, while task->exit_state are
118 * about the task exiting. Confusing, but this way
119 * modifying one set can't modify the other one by
120 * mistake.
121 */
122 #define TASK_RUNNING 0
123 #define TASK_INTERRUPTIBLE 1
124 #define TASK_UNINTERRUPTIBLE 2
125 #define TASK_STOPPED 4
126 #define TASK_TRACED 8
127 /* in tsk->exit_state */
128 #define EXIT_ZOMBIE 16
129 #define EXIT_DEAD 32
130 /* in tsk->state again */
131 #define TASK_NONINTERACTIVE 64
132
133 #define __set_task_state(tsk, state_value) \
134 do { (tsk)->state = (state_value); } while (0)
135 #define set_task_state(tsk, state_value) \
136 set_mb((tsk)->state, (state_value))
137
138 /*
139 * set_current_state() includes a barrier so that the write of current->state
140 * is correctly serialised wrt the caller's subsequent test of whether to
141 * actually sleep:
142 *
143 * set_current_state(TASK_UNINTERRUPTIBLE);
144 * if (do_i_need_to_sleep())
145 * schedule();
146 *
147 * If the caller does not need such serialisation then use __set_current_state()
148 */
149 #define __set_current_state(state_value) \
150 do { current->state = (state_value); } while (0)
151 #define set_current_state(state_value) \
152 set_mb(current->state, (state_value))
153
154 /* Task command name length */
155 #define TASK_COMM_LEN 16
156
157 /*
158 * Scheduling policies
159 */
160 #define SCHED_NORMAL 0
161 #define SCHED_FIFO 1
162 #define SCHED_RR 2
163 #define SCHED_BATCH 3
164
165 struct sched_param {
166 int sched_priority;
167 };
168
169 #ifdef __KERNEL__
170
171 #include <linux/spinlock.h>
172
173 /*
174 * This serializes "schedule()" and also protects
175 * the run-queue from deletions/modifications (but
176 * _adding_ to the beginning of the run-queue has
177 * a separate lock).
178 */
179 extern rwlock_t tasklist_lock;
180 extern spinlock_t mmlist_lock;
181
182 typedef struct task_struct task_t;
183
184 extern void sched_init(void);
185 extern void sched_init_smp(void);
186 extern void init_idle(task_t *idle, int cpu);
187
188 extern cpumask_t nohz_cpu_mask;
189
190 extern void show_state(void);
191 extern void show_regs(struct pt_regs *);
192
193 /*
194 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
195 * task), SP is the stack pointer of the first frame that should be shown in the back
196 * trace (or NULL if the entire call-chain of the task should be shown).
197 */
198 extern void show_stack(struct task_struct *task, unsigned long *sp);
199
200 void io_schedule(void);
201 long io_schedule_timeout(long timeout);
202
203 extern void cpu_init (void);
204 extern void trap_init(void);
205 extern void update_process_times(int user);
206 extern void scheduler_tick(void);
207
208 #ifdef CONFIG_DETECT_SOFTLOCKUP
209 extern void softlockup_tick(struct pt_regs *regs);
210 extern void spawn_softlockup_task(void);
211 extern void touch_softlockup_watchdog(void);
212 #else
213 static inline void softlockup_tick(struct pt_regs *regs)
214 {
215 }
216 static inline void spawn_softlockup_task(void)
217 {
218 }
219 static inline void touch_softlockup_watchdog(void)
220 {
221 }
222 #endif
223
224
225 /* Attach to any functions which should be ignored in wchan output. */
226 #define __sched __attribute__((__section__(".sched.text")))
227 /* Is this address in the __sched functions? */
228 extern int in_sched_functions(unsigned long addr);
229
230 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
231 extern signed long FASTCALL(schedule_timeout(signed long timeout));
232 extern signed long schedule_timeout_interruptible(signed long timeout);
233 extern signed long schedule_timeout_uninterruptible(signed long timeout);
234 asmlinkage void schedule(void);
235
236 struct namespace;
237
238 /* Maximum number of active map areas.. This is a random (large) number */
239 #define DEFAULT_MAX_MAP_COUNT 65536
240
241 extern int sysctl_max_map_count;
242
243 #include <linux/aio.h>
244
245 extern unsigned long
246 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
247 unsigned long, unsigned long);
248 extern unsigned long
249 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
250 unsigned long len, unsigned long pgoff,
251 unsigned long flags);
252 extern void arch_unmap_area(struct mm_struct *, unsigned long);
253 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
254
255 #if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
256 /*
257 * The mm counters are not protected by its page_table_lock,
258 * so must be incremented atomically.
259 */
260 #define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
261 #define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
262 #define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
263 #define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
264 #define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
265 typedef atomic_long_t mm_counter_t;
266
267 #else /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
268 /*
269 * The mm counters are protected by its page_table_lock,
270 * so can be incremented directly.
271 */
272 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
273 #define get_mm_counter(mm, member) ((mm)->_##member)
274 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
275 #define inc_mm_counter(mm, member) (mm)->_##member++
276 #define dec_mm_counter(mm, member) (mm)->_##member--
277 typedef unsigned long mm_counter_t;
278
279 #endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
280
281 #define get_mm_rss(mm) \
282 (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
283 #define update_hiwater_rss(mm) do { \
284 unsigned long _rss = get_mm_rss(mm); \
285 if ((mm)->hiwater_rss < _rss) \
286 (mm)->hiwater_rss = _rss; \
287 } while (0)
288 #define update_hiwater_vm(mm) do { \
289 if ((mm)->hiwater_vm < (mm)->total_vm) \
290 (mm)->hiwater_vm = (mm)->total_vm; \
291 } while (0)
292
293 struct mm_struct {
294 struct vm_area_struct * mmap; /* list of VMAs */
295 struct rb_root mm_rb;
296 struct vm_area_struct * mmap_cache; /* last find_vma result */
297 unsigned long (*get_unmapped_area) (struct file *filp,
298 unsigned long addr, unsigned long len,
299 unsigned long pgoff, unsigned long flags);
300 void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
301 unsigned long mmap_base; /* base of mmap area */
302 unsigned long task_size; /* size of task vm space */
303 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */
304 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */
305 pgd_t * pgd;
306 atomic_t mm_users; /* How many users with user space? */
307 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
308 int map_count; /* number of VMAs */
309 struct rw_semaphore mmap_sem;
310 spinlock_t page_table_lock; /* Protects page tables and some counters */
311
312 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
313 * together off init_mm.mmlist, and are protected
314 * by mmlist_lock
315 */
316
317 /* Special counters, in some configurations protected by the
318 * page_table_lock, in other configurations by being atomic.
319 */
320 mm_counter_t _file_rss;
321 mm_counter_t _anon_rss;
322
323 unsigned long hiwater_rss; /* High-watermark of RSS usage */
324 unsigned long hiwater_vm; /* High-water virtual memory usage */
325
326 unsigned long total_vm, locked_vm, shared_vm, exec_vm;
327 unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
328 unsigned long start_code, end_code, start_data, end_data;
329 unsigned long start_brk, brk, start_stack;
330 unsigned long arg_start, arg_end, env_start, env_end;
331
332 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
333
334 unsigned dumpable:2;
335 cpumask_t cpu_vm_mask;
336
337 /* Architecture-specific MM context */
338 mm_context_t context;
339
340 /* Token based thrashing protection. */
341 unsigned long swap_token_time;
342 char recent_pagein;
343
344 /* coredumping support */
345 int core_waiters;
346 struct completion *core_startup_done, core_done;
347
348 /* aio bits */
349 rwlock_t ioctx_list_lock;
350 struct kioctx *ioctx_list;
351 };
352
353 struct sighand_struct {
354 atomic_t count;
355 struct k_sigaction action[_NSIG];
356 spinlock_t siglock;
357 struct rcu_head rcu;
358 };
359
360 extern void sighand_free_cb(struct rcu_head *rhp);
361
362 static inline void sighand_free(struct sighand_struct *sp)
363 {
364 call_rcu(&sp->rcu, sighand_free_cb);
365 }
366
367 /*
368 * NOTE! "signal_struct" does not have it's own
369 * locking, because a shared signal_struct always
370 * implies a shared sighand_struct, so locking
371 * sighand_struct is always a proper superset of
372 * the locking of signal_struct.
373 */
374 struct signal_struct {
375 atomic_t count;
376 atomic_t live;
377
378 wait_queue_head_t wait_chldexit; /* for wait4() */
379
380 /* current thread group signal load-balancing target: */
381 task_t *curr_target;
382
383 /* shared signal handling: */
384 struct sigpending shared_pending;
385
386 /* thread group exit support */
387 int group_exit_code;
388 /* overloaded:
389 * - notify group_exit_task when ->count is equal to notify_count
390 * - everyone except group_exit_task is stopped during signal delivery
391 * of fatal signals, group_exit_task processes the signal.
392 */
393 struct task_struct *group_exit_task;
394 int notify_count;
395
396 /* thread group stop support, overloads group_exit_code too */
397 int group_stop_count;
398 unsigned int flags; /* see SIGNAL_* flags below */
399
400 /* POSIX.1b Interval Timers */
401 struct list_head posix_timers;
402
403 /* ITIMER_REAL timer for the process */
404 struct hrtimer real_timer;
405 ktime_t it_real_incr;
406
407 /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
408 cputime_t it_prof_expires, it_virt_expires;
409 cputime_t it_prof_incr, it_virt_incr;
410
411 /* job control IDs */
412 pid_t pgrp;
413 pid_t tty_old_pgrp;
414 pid_t session;
415 /* boolean value for session group leader */
416 int leader;
417
418 struct tty_struct *tty; /* NULL if no tty */
419
420 /*
421 * Cumulative resource counters for dead threads in the group,
422 * and for reaped dead child processes forked by this group.
423 * Live threads maintain their own counters and add to these
424 * in __exit_signal, except for the group leader.
425 */
426 cputime_t utime, stime, cutime, cstime;
427 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
428 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
429
430 /*
431 * Cumulative ns of scheduled CPU time for dead threads in the
432 * group, not including a zombie group leader. (This only differs
433 * from jiffies_to_ns(utime + stime) if sched_clock uses something
434 * other than jiffies.)
435 */
436 unsigned long long sched_time;
437
438 /*
439 * We don't bother to synchronize most readers of this at all,
440 * because there is no reader checking a limit that actually needs
441 * to get both rlim_cur and rlim_max atomically, and either one
442 * alone is a single word that can safely be read normally.
443 * getrlimit/setrlimit use task_lock(current->group_leader) to
444 * protect this instead of the siglock, because they really
445 * have no need to disable irqs.
446 */
447 struct rlimit rlim[RLIM_NLIMITS];
448
449 struct list_head cpu_timers[3];
450
451 /* keep the process-shared keyrings here so that they do the right
452 * thing in threads created with CLONE_THREAD */
453 #ifdef CONFIG_KEYS
454 struct key *session_keyring; /* keyring inherited over fork */
455 struct key *process_keyring; /* keyring private to this process */
456 #endif
457 };
458
459 /* Context switch must be unlocked if interrupts are to be enabled */
460 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
461 # define __ARCH_WANT_UNLOCKED_CTXSW
462 #endif
463
464 /*
465 * Bits in flags field of signal_struct.
466 */
467 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
468 #define SIGNAL_STOP_DEQUEUED 0x00000002 /* stop signal dequeued */
469 #define SIGNAL_STOP_CONTINUED 0x00000004 /* SIGCONT since WCONTINUED reap */
470 #define SIGNAL_GROUP_EXIT 0x00000008 /* group exit in progress */
471
472
473 /*
474 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
475 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
476 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
477 * values are inverted: lower p->prio value means higher priority.
478 *
479 * The MAX_USER_RT_PRIO value allows the actual maximum
480 * RT priority to be separate from the value exported to
481 * user-space. This allows kernel threads to set their
482 * priority to a value higher than any user task. Note:
483 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
484 */
485
486 #define MAX_USER_RT_PRIO 100
487 #define MAX_RT_PRIO MAX_USER_RT_PRIO
488
489 #define MAX_PRIO (MAX_RT_PRIO + 40)
490
491 #define rt_task(p) (unlikely((p)->prio < MAX_RT_PRIO))
492
493 /*
494 * Some day this will be a full-fledged user tracking system..
495 */
496 struct user_struct {
497 atomic_t __count; /* reference count */
498 atomic_t processes; /* How many processes does this user have? */
499 atomic_t files; /* How many open files does this user have? */
500 atomic_t sigpending; /* How many pending signals does this user have? */
501 #ifdef CONFIG_INOTIFY
502 atomic_t inotify_watches; /* How many inotify watches does this user have? */
503 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
504 #endif
505 /* protected by mq_lock */
506 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
507 unsigned long locked_shm; /* How many pages of mlocked shm ? */
508
509 #ifdef CONFIG_KEYS
510 struct key *uid_keyring; /* UID specific keyring */
511 struct key *session_keyring; /* UID's default session keyring */
512 #endif
513
514 /* Hash table maintenance information */
515 struct list_head uidhash_list;
516 uid_t uid;
517 };
518
519 extern struct user_struct *find_user(uid_t);
520
521 extern struct user_struct root_user;
522 #define INIT_USER (&root_user)
523
524 typedef struct prio_array prio_array_t;
525 struct backing_dev_info;
526 struct reclaim_state;
527
528 #ifdef CONFIG_SCHEDSTATS
529 struct sched_info {
530 /* cumulative counters */
531 unsigned long cpu_time, /* time spent on the cpu */
532 run_delay, /* time spent waiting on a runqueue */
533 pcnt; /* # of timeslices run on this cpu */
534
535 /* timestamps */
536 unsigned long last_arrival, /* when we last ran on a cpu */
537 last_queued; /* when we were last queued to run */
538 };
539
540 extern struct file_operations proc_schedstat_operations;
541 #endif
542
543 enum idle_type
544 {
545 SCHED_IDLE,
546 NOT_IDLE,
547 NEWLY_IDLE,
548 MAX_IDLE_TYPES
549 };
550
551 /*
552 * sched-domains (multiprocessor balancing) declarations:
553 */
554 #ifdef CONFIG_SMP
555 #define SCHED_LOAD_SCALE 128UL /* increase resolution of load */
556
557 #define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */
558 #define SD_BALANCE_NEWIDLE 2 /* Balance when about to become idle */
559 #define SD_BALANCE_EXEC 4 /* Balance on exec */
560 #define SD_BALANCE_FORK 8 /* Balance on fork, clone */
561 #define SD_WAKE_IDLE 16 /* Wake to idle CPU on task wakeup */
562 #define SD_WAKE_AFFINE 32 /* Wake task to waking CPU */
563 #define SD_WAKE_BALANCE 64 /* Perform balancing at task wakeup */
564 #define SD_SHARE_CPUPOWER 128 /* Domain members share cpu power */
565
566 struct sched_group {
567 struct sched_group *next; /* Must be a circular list */
568 cpumask_t cpumask;
569
570 /*
571 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
572 * single CPU. This is read only (except for setup, hotplug CPU).
573 */
574 unsigned long cpu_power;
575 };
576
577 struct sched_domain {
578 /* These fields must be setup */
579 struct sched_domain *parent; /* top domain must be null terminated */
580 struct sched_group *groups; /* the balancing groups of the domain */
581 cpumask_t span; /* span of all CPUs in this domain */
582 unsigned long min_interval; /* Minimum balance interval ms */
583 unsigned long max_interval; /* Maximum balance interval ms */
584 unsigned int busy_factor; /* less balancing by factor if busy */
585 unsigned int imbalance_pct; /* No balance until over watermark */
586 unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
587 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
588 unsigned int per_cpu_gain; /* CPU % gained by adding domain cpus */
589 unsigned int busy_idx;
590 unsigned int idle_idx;
591 unsigned int newidle_idx;
592 unsigned int wake_idx;
593 unsigned int forkexec_idx;
594 int flags; /* See SD_* */
595
596 /* Runtime fields. */
597 unsigned long last_balance; /* init to jiffies. units in jiffies */
598 unsigned int balance_interval; /* initialise to 1. units in ms. */
599 unsigned int nr_balance_failed; /* initialise to 0 */
600
601 #ifdef CONFIG_SCHEDSTATS
602 /* load_balance() stats */
603 unsigned long lb_cnt[MAX_IDLE_TYPES];
604 unsigned long lb_failed[MAX_IDLE_TYPES];
605 unsigned long lb_balanced[MAX_IDLE_TYPES];
606 unsigned long lb_imbalance[MAX_IDLE_TYPES];
607 unsigned long lb_gained[MAX_IDLE_TYPES];
608 unsigned long lb_hot_gained[MAX_IDLE_TYPES];
609 unsigned long lb_nobusyg[MAX_IDLE_TYPES];
610 unsigned long lb_nobusyq[MAX_IDLE_TYPES];
611
612 /* Active load balancing */
613 unsigned long alb_cnt;
614 unsigned long alb_failed;
615 unsigned long alb_pushed;
616
617 /* SD_BALANCE_EXEC stats */
618 unsigned long sbe_cnt;
619 unsigned long sbe_balanced;
620 unsigned long sbe_pushed;
621
622 /* SD_BALANCE_FORK stats */
623 unsigned long sbf_cnt;
624 unsigned long sbf_balanced;
625 unsigned long sbf_pushed;
626
627 /* try_to_wake_up() stats */
628 unsigned long ttwu_wake_remote;
629 unsigned long ttwu_move_affine;
630 unsigned long ttwu_move_balance;
631 #endif
632 };
633
634 extern void partition_sched_domains(cpumask_t *partition1,
635 cpumask_t *partition2);
636
637 /*
638 * Maximum cache size the migration-costs auto-tuning code will
639 * search from:
640 */
641 extern unsigned int max_cache_size;
642
643 #endif /* CONFIG_SMP */
644
645
646 struct io_context; /* See blkdev.h */
647 void exit_io_context(void);
648 struct cpuset;
649
650 #define NGROUPS_SMALL 32
651 #define NGROUPS_PER_BLOCK ((int)(PAGE_SIZE / sizeof(gid_t)))
652 struct group_info {
653 int ngroups;
654 atomic_t usage;
655 gid_t small_block[NGROUPS_SMALL];
656 int nblocks;
657 gid_t *blocks[0];
658 };
659
660 /*
661 * get_group_info() must be called with the owning task locked (via task_lock())
662 * when task != current. The reason being that the vast majority of callers are
663 * looking at current->group_info, which can not be changed except by the
664 * current task. Changing current->group_info requires the task lock, too.
665 */
666 #define get_group_info(group_info) do { \
667 atomic_inc(&(group_info)->usage); \
668 } while (0)
669
670 #define put_group_info(group_info) do { \
671 if (atomic_dec_and_test(&(group_info)->usage)) \
672 groups_free(group_info); \
673 } while (0)
674
675 extern struct group_info *groups_alloc(int gidsetsize);
676 extern void groups_free(struct group_info *group_info);
677 extern int set_current_groups(struct group_info *group_info);
678 extern int groups_search(struct group_info *group_info, gid_t grp);
679 /* access the groups "array" with this macro */
680 #define GROUP_AT(gi, i) \
681 ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK])
682
683 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
684 extern void prefetch_stack(struct task_struct*);
685 #else
686 static inline void prefetch_stack(struct task_struct *t) { }
687 #endif
688
689 struct audit_context; /* See audit.c */
690 struct mempolicy;
691
692 struct task_struct {
693 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
694 struct thread_info *thread_info;
695 atomic_t usage;
696 unsigned long flags; /* per process flags, defined below */
697 unsigned long ptrace;
698
699 int lock_depth; /* BKL lock depth */
700
701 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
702 int oncpu;
703 #endif
704 int prio, static_prio;
705 struct list_head run_list;
706 prio_array_t *array;
707
708 unsigned short ioprio;
709 unsigned int btrace_seq;
710
711 unsigned long sleep_avg;
712 unsigned long long timestamp, last_ran;
713 unsigned long long sched_time; /* sched_clock time spent running */
714 int activated;
715
716 unsigned long policy;
717 cpumask_t cpus_allowed;
718 unsigned int time_slice, first_time_slice;
719
720 #ifdef CONFIG_SCHEDSTATS
721 struct sched_info sched_info;
722 #endif
723
724 struct list_head tasks;
725 /*
726 * ptrace_list/ptrace_children forms the list of my children
727 * that were stolen by a ptracer.
728 */
729 struct list_head ptrace_children;
730 struct list_head ptrace_list;
731
732 struct mm_struct *mm, *active_mm;
733
734 /* task state */
735 struct linux_binfmt *binfmt;
736 long exit_state;
737 int exit_code, exit_signal;
738 int pdeath_signal; /* The signal sent when the parent dies */
739 /* ??? */
740 unsigned long personality;
741 unsigned did_exec:1;
742 pid_t pid;
743 pid_t tgid;
744 /*
745 * pointers to (original) parent process, youngest child, younger sibling,
746 * older sibling, respectively. (p->father can be replaced with
747 * p->parent->pid)
748 */
749 struct task_struct *real_parent; /* real parent process (when being debugged) */
750 struct task_struct *parent; /* parent process */
751 /*
752 * children/sibling forms the list of my children plus the
753 * tasks I'm ptracing.
754 */
755 struct list_head children; /* list of my children */
756 struct list_head sibling; /* linkage in my parent's children list */
757 struct task_struct *group_leader; /* threadgroup leader */
758
759 /* PID/PID hash table linkage. */
760 struct pid pids[PIDTYPE_MAX];
761
762 struct completion *vfork_done; /* for vfork() */
763 int __user *set_child_tid; /* CLONE_CHILD_SETTID */
764 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
765
766 unsigned long rt_priority;
767 cputime_t utime, stime;
768 unsigned long nvcsw, nivcsw; /* context switch counts */
769 struct timespec start_time;
770 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
771 unsigned long min_flt, maj_flt;
772
773 cputime_t it_prof_expires, it_virt_expires;
774 unsigned long long it_sched_expires;
775 struct list_head cpu_timers[3];
776
777 /* process credentials */
778 uid_t uid,euid,suid,fsuid;
779 gid_t gid,egid,sgid,fsgid;
780 struct group_info *group_info;
781 kernel_cap_t cap_effective, cap_inheritable, cap_permitted;
782 unsigned keep_capabilities:1;
783 struct user_struct *user;
784 #ifdef CONFIG_KEYS
785 struct key *request_key_auth; /* assumed request_key authority */
786 struct key *thread_keyring; /* keyring private to this thread */
787 unsigned char jit_keyring; /* default keyring to attach requested keys to */
788 #endif
789 int oomkilladj; /* OOM kill score adjustment (bit shift). */
790 char comm[TASK_COMM_LEN]; /* executable name excluding path
791 - access with [gs]et_task_comm (which lock
792 it with task_lock())
793 - initialized normally by flush_old_exec */
794 /* file system info */
795 int link_count, total_link_count;
796 /* ipc stuff */
797 struct sysv_sem sysvsem;
798 /* CPU-specific state of this task */
799 struct thread_struct thread;
800 /* filesystem information */
801 struct fs_struct *fs;
802 /* open file information */
803 struct files_struct *files;
804 /* namespace */
805 struct namespace *namespace;
806 /* signal handlers */
807 struct signal_struct *signal;
808 struct sighand_struct *sighand;
809
810 sigset_t blocked, real_blocked;
811 sigset_t saved_sigmask; /* To be restored with TIF_RESTORE_SIGMASK */
812 struct sigpending pending;
813
814 unsigned long sas_ss_sp;
815 size_t sas_ss_size;
816 int (*notifier)(void *priv);
817 void *notifier_data;
818 sigset_t *notifier_mask;
819
820 void *security;
821 struct audit_context *audit_context;
822 seccomp_t seccomp;
823
824 /* Thread group tracking */
825 u32 parent_exec_id;
826 u32 self_exec_id;
827 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
828 spinlock_t alloc_lock;
829 /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
830 spinlock_t proc_lock;
831
832 #ifdef CONFIG_DEBUG_MUTEXES
833 /* mutex deadlock detection */
834 struct mutex_waiter *blocked_on;
835 #endif
836
837 /* journalling filesystem info */
838 void *journal_info;
839
840 /* VM state */
841 struct reclaim_state *reclaim_state;
842
843 struct dentry *proc_dentry;
844 struct backing_dev_info *backing_dev_info;
845
846 struct io_context *io_context;
847
848 unsigned long ptrace_message;
849 siginfo_t *last_siginfo; /* For ptrace use. */
850 /*
851 * current io wait handle: wait queue entry to use for io waits
852 * If this thread is processing aio, this points at the waitqueue
853 * inside the currently handled kiocb. It may be NULL (i.e. default
854 * to a stack based synchronous wait) if its doing sync IO.
855 */
856 wait_queue_t *io_wait;
857 /* i/o counters(bytes read/written, #syscalls */
858 u64 rchar, wchar, syscr, syscw;
859 #if defined(CONFIG_BSD_PROCESS_ACCT)
860 u64 acct_rss_mem1; /* accumulated rss usage */
861 u64 acct_vm_mem1; /* accumulated virtual memory usage */
862 clock_t acct_stimexpd; /* clock_t-converted stime since last update */
863 #endif
864 #ifdef CONFIG_NUMA
865 struct mempolicy *mempolicy;
866 short il_next;
867 #endif
868 #ifdef CONFIG_CPUSETS
869 struct cpuset *cpuset;
870 nodemask_t mems_allowed;
871 int cpuset_mems_generation;
872 #endif
873 atomic_t fs_excl; /* holding fs exclusive resources */
874 struct rcu_head rcu;
875 };
876
877 static inline pid_t process_group(struct task_struct *tsk)
878 {
879 return tsk->signal->pgrp;
880 }
881
882 /**
883 * pid_alive - check that a task structure is not stale
884 * @p: Task structure to be checked.
885 *
886 * Test if a process is not yet dead (at most zombie state)
887 * If pid_alive fails, then pointers within the task structure
888 * can be stale and must not be dereferenced.
889 */
890 static inline int pid_alive(struct task_struct *p)
891 {
892 return p->pids[PIDTYPE_PID].nr != 0;
893 }
894
895 extern void free_task(struct task_struct *tsk);
896 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
897
898 extern void __put_task_struct_cb(struct rcu_head *rhp);
899
900 static inline void put_task_struct(struct task_struct *t)
901 {
902 if (atomic_dec_and_test(&t->usage))
903 call_rcu(&t->rcu, __put_task_struct_cb);
904 }
905
906 /*
907 * Per process flags
908 */
909 #define PF_ALIGNWARN 0x00000001 /* Print alignment warning msgs */
910 /* Not implemented yet, only for 486*/
911 #define PF_STARTING 0x00000002 /* being created */
912 #define PF_EXITING 0x00000004 /* getting shut down */
913 #define PF_DEAD 0x00000008 /* Dead */
914 #define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
915 #define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
916 #define PF_DUMPCORE 0x00000200 /* dumped core */
917 #define PF_SIGNALED 0x00000400 /* killed by a signal */
918 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
919 #define PF_FLUSHER 0x00001000 /* responsible for disk writeback */
920 #define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
921 #define PF_FREEZE 0x00004000 /* this task is being frozen for suspend now */
922 #define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
923 #define PF_FROZEN 0x00010000 /* frozen for system suspend */
924 #define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
925 #define PF_KSWAPD 0x00040000 /* I am kswapd */
926 #define PF_SWAPOFF 0x00080000 /* I am in swapoff */
927 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
928 #define PF_SYNCWRITE 0x00200000 /* I am doing a sync write */
929 #define PF_BORROWED_MM 0x00400000 /* I am a kthread doing use_mm */
930 #define PF_RANDOMIZE 0x00800000 /* randomize virtual address space */
931 #define PF_SWAPWRITE 0x01000000 /* Allowed to write to swap */
932
933 /*
934 * Only the _current_ task can read/write to tsk->flags, but other
935 * tasks can access tsk->flags in readonly mode for example
936 * with tsk_used_math (like during threaded core dumping).
937 * There is however an exception to this rule during ptrace
938 * or during fork: the ptracer task is allowed to write to the
939 * child->flags of its traced child (same goes for fork, the parent
940 * can write to the child->flags), because we're guaranteed the
941 * child is not running and in turn not changing child->flags
942 * at the same time the parent does it.
943 */
944 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
945 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
946 #define clear_used_math() clear_stopped_child_used_math(current)
947 #define set_used_math() set_stopped_child_used_math(current)
948 #define conditional_stopped_child_used_math(condition, child) \
949 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
950 #define conditional_used_math(condition) \
951 conditional_stopped_child_used_math(condition, current)
952 #define copy_to_stopped_child_used_math(child) \
953 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
954 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
955 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
956 #define used_math() tsk_used_math(current)
957
958 #ifdef CONFIG_SMP
959 extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
960 #else
961 static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)
962 {
963 if (!cpu_isset(0, new_mask))
964 return -EINVAL;
965 return 0;
966 }
967 #endif
968
969 extern unsigned long long sched_clock(void);
970 extern unsigned long long current_sched_time(const task_t *current_task);
971
972 /* sched_exec is called by processes performing an exec */
973 #ifdef CONFIG_SMP
974 extern void sched_exec(void);
975 #else
976 #define sched_exec() {}
977 #endif
978
979 #ifdef CONFIG_HOTPLUG_CPU
980 extern void idle_task_exit(void);
981 #else
982 static inline void idle_task_exit(void) {}
983 #endif
984
985 extern void sched_idle_next(void);
986 extern void set_user_nice(task_t *p, long nice);
987 extern int task_prio(const task_t *p);
988 extern int task_nice(const task_t *p);
989 extern int can_nice(const task_t *p, const int nice);
990 extern int task_curr(const task_t *p);
991 extern int idle_cpu(int cpu);
992 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
993 extern task_t *idle_task(int cpu);
994 extern task_t *curr_task(int cpu);
995 extern void set_curr_task(int cpu, task_t *p);
996
997 void yield(void);
998
999 /*
1000 * The default (Linux) execution domain.
1001 */
1002 extern struct exec_domain default_exec_domain;
1003
1004 union thread_union {
1005 struct thread_info thread_info;
1006 unsigned long stack[THREAD_SIZE/sizeof(long)];
1007 };
1008
1009 #ifndef __HAVE_ARCH_KSTACK_END
1010 static inline int kstack_end(void *addr)
1011 {
1012 /* Reliable end of stack detection:
1013 * Some APM bios versions misalign the stack
1014 */
1015 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1016 }
1017 #endif
1018
1019 extern union thread_union init_thread_union;
1020 extern struct task_struct init_task;
1021
1022 extern struct mm_struct init_mm;
1023
1024 #define find_task_by_pid(nr) find_task_by_pid_type(PIDTYPE_PID, nr)
1025 extern struct task_struct *find_task_by_pid_type(int type, int pid);
1026 extern void set_special_pids(pid_t session, pid_t pgrp);
1027 extern void __set_special_pids(pid_t session, pid_t pgrp);
1028
1029 /* per-UID process charging. */
1030 extern struct user_struct * alloc_uid(uid_t);
1031 static inline struct user_struct *get_uid(struct user_struct *u)
1032 {
1033 atomic_inc(&u->__count);
1034 return u;
1035 }
1036 extern void free_uid(struct user_struct *);
1037 extern void switch_uid(struct user_struct *);
1038
1039 #include <asm/current.h>
1040
1041 extern void do_timer(struct pt_regs *);
1042
1043 extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
1044 extern int FASTCALL(wake_up_process(struct task_struct * tsk));
1045 extern void FASTCALL(wake_up_new_task(struct task_struct * tsk,
1046 unsigned long clone_flags));
1047 #ifdef CONFIG_SMP
1048 extern void kick_process(struct task_struct *tsk);
1049 #else
1050 static inline void kick_process(struct task_struct *tsk) { }
1051 #endif
1052 extern void FASTCALL(sched_fork(task_t * p, int clone_flags));
1053 extern void FASTCALL(sched_exit(task_t * p));
1054
1055 extern int in_group_p(gid_t);
1056 extern int in_egroup_p(gid_t);
1057
1058 extern void proc_caches_init(void);
1059 extern void flush_signals(struct task_struct *);
1060 extern void flush_signal_handlers(struct task_struct *, int force_default);
1061 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1062
1063 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1064 {
1065 unsigned long flags;
1066 int ret;
1067
1068 spin_lock_irqsave(&tsk->sighand->siglock, flags);
1069 ret = dequeue_signal(tsk, mask, info);
1070 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1071
1072 return ret;
1073 }
1074
1075 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1076 sigset_t *mask);
1077 extern void unblock_all_signals(void);
1078 extern void release_task(struct task_struct * p);
1079 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
1080 extern int send_group_sig_info(int, struct siginfo *, struct task_struct *);
1081 extern int force_sigsegv(int, struct task_struct *);
1082 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
1083 extern int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp);
1084 extern int kill_pg_info(int, struct siginfo *, pid_t);
1085 extern int kill_proc_info(int, struct siginfo *, pid_t);
1086 extern int kill_proc_info_as_uid(int, struct siginfo *, pid_t, uid_t, uid_t);
1087 extern void do_notify_parent(struct task_struct *, int);
1088 extern void force_sig(int, struct task_struct *);
1089 extern void force_sig_specific(int, struct task_struct *);
1090 extern int send_sig(int, struct task_struct *, int);
1091 extern void zap_other_threads(struct task_struct *p);
1092 extern int kill_pg(pid_t, int, int);
1093 extern int kill_sl(pid_t, int, int);
1094 extern int kill_proc(pid_t, int, int);
1095 extern struct sigqueue *sigqueue_alloc(void);
1096 extern void sigqueue_free(struct sigqueue *);
1097 extern int send_sigqueue(int, struct sigqueue *, struct task_struct *);
1098 extern int send_group_sigqueue(int, struct sigqueue *, struct task_struct *);
1099 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
1100 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1101
1102 /* These can be the second arg to send_sig_info/send_group_sig_info. */
1103 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
1104 #define SEND_SIG_PRIV ((struct siginfo *) 1)
1105 #define SEND_SIG_FORCED ((struct siginfo *) 2)
1106
1107 static inline int is_si_special(const struct siginfo *info)
1108 {
1109 return info <= SEND_SIG_FORCED;
1110 }
1111
1112 /* True if we are on the alternate signal stack. */
1113
1114 static inline int on_sig_stack(unsigned long sp)
1115 {
1116 return (sp - current->sas_ss_sp < current->sas_ss_size);
1117 }
1118
1119 static inline int sas_ss_flags(unsigned long sp)
1120 {
1121 return (current->sas_ss_size == 0 ? SS_DISABLE
1122 : on_sig_stack(sp) ? SS_ONSTACK : 0);
1123 }
1124
1125 /*
1126 * Routines for handling mm_structs
1127 */
1128 extern struct mm_struct * mm_alloc(void);
1129
1130 /* mmdrop drops the mm and the page tables */
1131 extern void FASTCALL(__mmdrop(struct mm_struct *));
1132 static inline void mmdrop(struct mm_struct * mm)
1133 {
1134 if (atomic_dec_and_test(&mm->mm_count))
1135 __mmdrop(mm);
1136 }
1137
1138 /* mmput gets rid of the mappings and all user-space */
1139 extern void mmput(struct mm_struct *);
1140 /* Grab a reference to a task's mm, if it is not already going away */
1141 extern struct mm_struct *get_task_mm(struct task_struct *task);
1142 /* Remove the current tasks stale references to the old mm_struct */
1143 extern void mm_release(struct task_struct *, struct mm_struct *);
1144
1145 extern int copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
1146 extern void flush_thread(void);
1147 extern void exit_thread(void);
1148
1149 extern void exit_files(struct task_struct *);
1150 extern void exit_signal(struct task_struct *);
1151 extern void __exit_signal(struct task_struct *);
1152 extern void exit_sighand(struct task_struct *);
1153 extern void __exit_sighand(struct task_struct *);
1154 extern void exit_itimers(struct signal_struct *);
1155
1156 extern NORET_TYPE void do_group_exit(int);
1157
1158 extern void daemonize(const char *, ...);
1159 extern int allow_signal(int);
1160 extern int disallow_signal(int);
1161 extern task_t *child_reaper;
1162
1163 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1164 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
1165 task_t *fork_idle(int);
1166
1167 extern void set_task_comm(struct task_struct *tsk, char *from);
1168 extern void get_task_comm(char *to, struct task_struct *tsk);
1169
1170 #ifdef CONFIG_SMP
1171 extern void wait_task_inactive(task_t * p);
1172 #else
1173 #define wait_task_inactive(p) do { } while (0)
1174 #endif
1175
1176 #define remove_parent(p) list_del_init(&(p)->sibling)
1177 #define add_parent(p, parent) list_add_tail(&(p)->sibling,&(parent)->children)
1178
1179 #define REMOVE_LINKS(p) do { \
1180 if (thread_group_leader(p)) \
1181 list_del_init(&(p)->tasks); \
1182 remove_parent(p); \
1183 } while (0)
1184
1185 #define SET_LINKS(p) do { \
1186 if (thread_group_leader(p)) \
1187 list_add_tail(&(p)->tasks,&init_task.tasks); \
1188 add_parent(p, (p)->parent); \
1189 } while (0)
1190
1191 #define next_task(p) list_entry((p)->tasks.next, struct task_struct, tasks)
1192 #define prev_task(p) list_entry((p)->tasks.prev, struct task_struct, tasks)
1193
1194 #define for_each_process(p) \
1195 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
1196
1197 /*
1198 * Careful: do_each_thread/while_each_thread is a double loop so
1199 * 'break' will not work as expected - use goto instead.
1200 */
1201 #define do_each_thread(g, t) \
1202 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
1203
1204 #define while_each_thread(g, t) \
1205 while ((t = next_thread(t)) != g)
1206
1207 extern task_t * FASTCALL(next_thread(const task_t *p));
1208
1209 #define thread_group_leader(p) (p->pid == p->tgid)
1210
1211 static inline int thread_group_empty(task_t *p)
1212 {
1213 return list_empty(&p->pids[PIDTYPE_TGID].pid_list);
1214 }
1215
1216 #define delay_group_leader(p) \
1217 (thread_group_leader(p) && !thread_group_empty(p))
1218
1219 extern void unhash_process(struct task_struct *p);
1220
1221 /*
1222 * Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring
1223 * subscriptions and synchronises with wait4(). Also used in procfs. Also
1224 * pins the final release of task.io_context. Also protects ->cpuset.
1225 *
1226 * Nests both inside and outside of read_lock(&tasklist_lock).
1227 * It must not be nested with write_lock_irq(&tasklist_lock),
1228 * neither inside nor outside.
1229 */
1230 static inline void task_lock(struct task_struct *p)
1231 {
1232 spin_lock(&p->alloc_lock);
1233 }
1234
1235 static inline void task_unlock(struct task_struct *p)
1236 {
1237 spin_unlock(&p->alloc_lock);
1238 }
1239
1240 #ifndef __HAVE_THREAD_FUNCTIONS
1241
1242 #define task_thread_info(task) (task)->thread_info
1243 #define task_stack_page(task) ((void*)((task)->thread_info))
1244
1245 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
1246 {
1247 *task_thread_info(p) = *task_thread_info(org);
1248 task_thread_info(p)->task = p;
1249 }
1250
1251 static inline unsigned long *end_of_stack(struct task_struct *p)
1252 {
1253 return (unsigned long *)(p->thread_info + 1);
1254 }
1255
1256 #endif
1257
1258 /* set thread flags in other task's structures
1259 * - see asm/thread_info.h for TIF_xxxx flags available
1260 */
1261 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1262 {
1263 set_ti_thread_flag(task_thread_info(tsk), flag);
1264 }
1265
1266 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1267 {
1268 clear_ti_thread_flag(task_thread_info(tsk), flag);
1269 }
1270
1271 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1272 {
1273 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1274 }
1275
1276 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1277 {
1278 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1279 }
1280
1281 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1282 {
1283 return test_ti_thread_flag(task_thread_info(tsk), flag);
1284 }
1285
1286 static inline void set_tsk_need_resched(struct task_struct *tsk)
1287 {
1288 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1289 }
1290
1291 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1292 {
1293 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1294 }
1295
1296 static inline int signal_pending(struct task_struct *p)
1297 {
1298 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
1299 }
1300
1301 static inline int need_resched(void)
1302 {
1303 return unlikely(test_thread_flag(TIF_NEED_RESCHED));
1304 }
1305
1306 /*
1307 * cond_resched() and cond_resched_lock(): latency reduction via
1308 * explicit rescheduling in places that are safe. The return
1309 * value indicates whether a reschedule was done in fact.
1310 * cond_resched_lock() will drop the spinlock before scheduling,
1311 * cond_resched_softirq() will enable bhs before scheduling.
1312 */
1313 extern int cond_resched(void);
1314 extern int cond_resched_lock(spinlock_t * lock);
1315 extern int cond_resched_softirq(void);
1316
1317 /*
1318 * Does a critical section need to be broken due to another
1319 * task waiting?:
1320 */
1321 #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
1322 # define need_lockbreak(lock) ((lock)->break_lock)
1323 #else
1324 # define need_lockbreak(lock) 0
1325 #endif
1326
1327 /*
1328 * Does a critical section need to be broken due to another
1329 * task waiting or preemption being signalled:
1330 */
1331 static inline int lock_need_resched(spinlock_t *lock)
1332 {
1333 if (need_lockbreak(lock) || need_resched())
1334 return 1;
1335 return 0;
1336 }
1337
1338 /* Reevaluate whether the task has signals pending delivery.
1339 This is required every time the blocked sigset_t changes.
1340 callers must hold sighand->siglock. */
1341
1342 extern FASTCALL(void recalc_sigpending_tsk(struct task_struct *t));
1343 extern void recalc_sigpending(void);
1344
1345 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
1346
1347 /*
1348 * Wrappers for p->thread_info->cpu access. No-op on UP.
1349 */
1350 #ifdef CONFIG_SMP
1351
1352 static inline unsigned int task_cpu(const struct task_struct *p)
1353 {
1354 return task_thread_info(p)->cpu;
1355 }
1356
1357 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1358 {
1359 task_thread_info(p)->cpu = cpu;
1360 }
1361
1362 #else
1363
1364 static inline unsigned int task_cpu(const struct task_struct *p)
1365 {
1366 return 0;
1367 }
1368
1369 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1370 {
1371 }
1372
1373 #endif /* CONFIG_SMP */
1374
1375 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1376 extern void arch_pick_mmap_layout(struct mm_struct *mm);
1377 #else
1378 static inline void arch_pick_mmap_layout(struct mm_struct *mm)
1379 {
1380 mm->mmap_base = TASK_UNMAPPED_BASE;
1381 mm->get_unmapped_area = arch_get_unmapped_area;
1382 mm->unmap_area = arch_unmap_area;
1383 }
1384 #endif
1385
1386 extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
1387 extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
1388
1389 extern void normalize_rt_tasks(void);
1390
1391 #ifdef CONFIG_PM
1392 /*
1393 * Check if a process has been frozen
1394 */
1395 static inline int frozen(struct task_struct *p)
1396 {
1397 return p->flags & PF_FROZEN;
1398 }
1399
1400 /*
1401 * Check if there is a request to freeze a process
1402 */
1403 static inline int freezing(struct task_struct *p)
1404 {
1405 return p->flags & PF_FREEZE;
1406 }
1407
1408 /*
1409 * Request that a process be frozen
1410 * FIXME: SMP problem. We may not modify other process' flags!
1411 */
1412 static inline void freeze(struct task_struct *p)
1413 {
1414 p->flags |= PF_FREEZE;
1415 }
1416
1417 /*
1418 * Wake up a frozen process
1419 */
1420 static inline int thaw_process(struct task_struct *p)
1421 {
1422 if (frozen(p)) {
1423 p->flags &= ~PF_FROZEN;
1424 wake_up_process(p);
1425 return 1;
1426 }
1427 return 0;
1428 }
1429
1430 /*
1431 * freezing is complete, mark process as frozen
1432 */
1433 static inline void frozen_process(struct task_struct *p)
1434 {
1435 p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
1436 }
1437
1438 extern void refrigerator(void);
1439 extern int freeze_processes(void);
1440 extern void thaw_processes(void);
1441
1442 static inline int try_to_freeze(void)
1443 {
1444 if (freezing(current)) {
1445 refrigerator();
1446 return 1;
1447 } else
1448 return 0;
1449 }
1450 #else
1451 static inline int frozen(struct task_struct *p) { return 0; }
1452 static inline int freezing(struct task_struct *p) { return 0; }
1453 static inline void freeze(struct task_struct *p) { BUG(); }
1454 static inline int thaw_process(struct task_struct *p) { return 1; }
1455 static inline void frozen_process(struct task_struct *p) { BUG(); }
1456
1457 static inline void refrigerator(void) {}
1458 static inline int freeze_processes(void) { BUG(); return 0; }
1459 static inline void thaw_processes(void) {}
1460
1461 static inline int try_to_freeze(void) { return 0; }
1462
1463 #endif /* CONFIG_PM */
1464 #endif /* __KERNEL__ */
1465
1466 #endif
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