blob: 52b8cd049c2e0a9f63a0207489b718fa43eae21c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_SCHED_H
2#define _LINUX_SCHED_H
3
David Woodhouseb7b3c762006-04-27 00:12:56 +01004/*
5 * cloning flags:
6 */
7#define CSIGNAL 0x000000ff /* signal mask to be sent at exit */
8#define CLONE_VM 0x00000100 /* set if VM shared between processes */
9#define CLONE_FS 0x00000200 /* set if fs info shared between processes */
10#define CLONE_FILES 0x00000400 /* set if open files shared between processes */
11#define CLONE_SIGHAND 0x00000800 /* set if signal handlers and blocked signals shared */
12#define CLONE_PTRACE 0x00002000 /* set if we want to let tracing continue on the child too */
13#define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */
14#define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */
15#define CLONE_THREAD 0x00010000 /* Same thread group? */
16#define CLONE_NEWNS 0x00020000 /* New namespace group? */
17#define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */
18#define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */
19#define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */
20#define CLONE_CHILD_CLEARTID 0x00200000 /* clear the TID in the child */
21#define CLONE_DETACHED 0x00400000 /* Unused, ignored */
22#define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */
23#define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
24#define CLONE_STOPPED 0x02000000 /* Start in stopped state */
Serge E. Hallyn071df102006-10-02 02:18:17 -070025#define CLONE_NEWUTS 0x04000000 /* New utsname group? */
Kirill Korotaev25b21cb2006-10-02 02:18:19 -070026#define CLONE_NEWIPC 0x08000000 /* New ipcs */
Serge E. Hallyn77ec7392007-07-15 23:41:01 -070027#define CLONE_NEWUSER 0x10000000 /* New user namespace */
Pavel Emelyanov30e49c22007-10-18 23:40:10 -070028#define CLONE_NEWPID 0x20000000 /* New pid namespace */
Eric W. Biederman169e3672007-09-27 17:10:06 -070029#define CLONE_NEWNET 0x40000000 /* New network namespace */
Jens Axboefadad8782008-01-24 08:54:47 +010030#define CLONE_IO 0x80000000 /* Clone io context */
David Woodhouseb7b3c762006-04-27 00:12:56 +010031
32/*
33 * Scheduling policies
34 */
35#define SCHED_NORMAL 0
36#define SCHED_FIFO 1
37#define SCHED_RR 2
38#define SCHED_BATCH 3
Ingo Molnar0e6aca42007-07-09 18:51:57 +020039/* SCHED_ISO: reserved but not implemented yet */
40#define SCHED_IDLE 5
David Woodhouseb7b3c762006-04-27 00:12:56 +010041
David Woodhousea3b67142006-04-25 14:54:40 +010042#ifdef __KERNEL__
David Woodhouseb7b3c762006-04-27 00:12:56 +010043
44struct sched_param {
45 int sched_priority;
46};
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <asm/param.h> /* for HZ */
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <linux/capability.h>
51#include <linux/threads.h>
52#include <linux/kernel.h>
53#include <linux/types.h>
54#include <linux/timex.h>
55#include <linux/jiffies.h>
56#include <linux/rbtree.h>
57#include <linux/thread_info.h>
58#include <linux/cpumask.h>
59#include <linux/errno.h>
60#include <linux/nodemask.h>
Martin Schwidefskyc92ff1b2007-10-16 01:24:43 -070061#include <linux/mm_types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63#include <asm/system.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070064#include <asm/page.h>
65#include <asm/ptrace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#include <asm/cputime.h>
67
68#include <linux/smp.h>
69#include <linux/sem.h>
70#include <linux/signal.h>
Al Viro5ad4e532009-03-29 19:50:06 -040071#include <linux/path.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072#include <linux/compiler.h>
73#include <linux/completion.h>
74#include <linux/pid.h>
75#include <linux/percpu.h>
76#include <linux/topology.h>
Peter Zijlstra3e26c142007-10-16 23:25:50 -070077#include <linux/proportions.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#include <linux/seccomp.h>
Ingo Molnare56d0902006-01-08 01:01:37 -080079#include <linux/rcupdate.h>
Ingo Molnar23f78d4a2006-06-27 02:54:53 -070080#include <linux/rtmutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
David Woodhousea3b67142006-04-25 14:54:40 +010082#include <linux/time.h>
83#include <linux/param.h>
84#include <linux/resource.h>
85#include <linux/timer.h>
86#include <linux/hrtimer.h>
Andrew Morton7c3ab732006-12-10 02:19:19 -080087#include <linux/task_io_accounting.h>
Dhaval Giani5cb350b2007-10-15 17:00:14 +020088#include <linux/kobject.h>
Arjan van de Ven97455122008-01-25 21:08:34 +010089#include <linux/latencytop.h>
David Howells9e2b2dc2008-08-13 16:20:04 +010090#include <linux/cred.h>
David Woodhousea3b67142006-04-25 14:54:40 +010091
92#include <asm/processor.h>
H. J. Lu36d57ac2005-09-06 15:16:49 -070093
Pavel Emelianov78fb7462008-02-07 00:13:51 -080094struct mem_cgroup;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095struct exec_domain;
Ingo Molnarc87e2832006-06-27 02:54:58 -070096struct futex_pi_state;
Alexey Dobriyan286100a2008-01-25 21:08:34 +010097struct robust_list_head;
Neil Brownd89d8792007-05-01 09:53:42 +020098struct bio;
Al Viro5ad4e532009-03-29 19:50:06 -040099struct fs_struct;
Markus Metzgere2b371f2009-04-03 16:43:35 +0200100struct bts_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 * List of flags we want to share for kernel threads,
104 * if only because they are not used by them anyway.
105 */
106#define CLONE_KERNEL (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
107
108/*
109 * These are the constant used to fake the fixed-point load-average
110 * counting. Some notes:
111 * - 11 bit fractions expand to 22 bits by the multiplies: this gives
112 * a load-average precision of 10 bits integer + 11 bits fractional
113 * - if you want to count load-averages more often, you need more
114 * precision, or rounding will get you. With 2-second counting freq,
115 * the EXP_n values would be 1981, 2034 and 2043 if still using only
116 * 11 bit fractions.
117 */
118extern unsigned long avenrun[]; /* Load averages */
119
120#define FSHIFT 11 /* nr of bits of precision */
121#define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
Linus Torvalds0c2043a2007-10-07 16:17:38 -0700122#define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123#define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
124#define EXP_5 2014 /* 1/exp(5sec/5min) */
125#define EXP_15 2037 /* 1/exp(5sec/15min) */
126
127#define CALC_LOAD(load,exp,n) \
128 load *= exp; \
129 load += n*(FIXED_1-exp); \
130 load >>= FSHIFT;
131
132extern unsigned long total_forks;
133extern int nr_threads;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134DECLARE_PER_CPU(unsigned long, process_counts);
135extern int nr_processes(void);
136extern unsigned long nr_running(void);
137extern unsigned long nr_uninterruptible(void);
Jack Steinerdb1b1fe2006-03-31 02:31:21 -0800138extern unsigned long nr_active(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139extern unsigned long nr_iowait(void);
140
Steven Rostedt7e49fcc2009-01-22 19:01:40 -0500141extern unsigned long get_parent_ip(unsigned long addr);
142
Ingo Molnar43ae34c2007-07-09 18:52:00 +0200143struct seq_file;
144struct cfs_rq;
Ingo Molnar4cf86d72007-10-15 17:00:14 +0200145struct task_group;
Ingo Molnar43ae34c2007-07-09 18:52:00 +0200146#ifdef CONFIG_SCHED_DEBUG
147extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
148extern void proc_sched_set_task(struct task_struct *p);
149extern void
Ingo Molnar5cef9ec2007-08-09 11:16:47 +0200150print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
Ingo Molnar43ae34c2007-07-09 18:52:00 +0200151#else
152static inline void
153proc_sched_show_task(struct task_struct *p, struct seq_file *m)
154{
155}
156static inline void proc_sched_set_task(struct task_struct *p)
157{
158}
159static inline void
Ingo Molnar5cef9ec2007-08-09 11:16:47 +0200160print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
Ingo Molnar43ae34c2007-07-09 18:52:00 +0200161{
162}
163#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
Ingo Molnar690229a2008-04-23 09:31:35 +0200165extern unsigned long long time_sync_thresh;
166
Linus Torvalds4a8342d2005-09-29 15:18:21 -0700167/*
168 * Task state bitmask. NOTE! These bits are also
169 * encoded in fs/proc/array.c: get_task_state().
170 *
171 * We have two separate sets of flags: task->state
172 * is about runnability, while task->exit_state are
173 * about the task exiting. Confusing, but this way
174 * modifying one set can't modify the other one by
175 * mistake.
176 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177#define TASK_RUNNING 0
178#define TASK_INTERRUPTIBLE 1
179#define TASK_UNINTERRUPTIBLE 2
Matthew Wilcoxf021a3c2007-12-06 11:13:16 -0500180#define __TASK_STOPPED 4
181#define __TASK_TRACED 8
Linus Torvalds4a8342d2005-09-29 15:18:21 -0700182/* in tsk->exit_state */
183#define EXIT_ZOMBIE 16
184#define EXIT_DEAD 32
185/* in tsk->state again */
Mike Galbraithaf927232007-10-15 17:00:13 +0200186#define TASK_DEAD 64
Matthew Wilcoxf021a3c2007-12-06 11:13:16 -0500187#define TASK_WAKEKILL 128
188
189/* Convenience macros for the sake of set_task_state */
190#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
191#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
192#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
Matthew Wilcox92a1f4b2007-12-06 10:55:25 -0500194/* Convenience macros for the sake of wake_up */
195#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
Matthew Wilcoxf021a3c2007-12-06 11:13:16 -0500196#define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
Matthew Wilcox92a1f4b2007-12-06 10:55:25 -0500197
198/* get_task_state() */
199#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
Matthew Wilcoxf021a3c2007-12-06 11:13:16 -0500200 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
201 __TASK_TRACED)
Matthew Wilcox92a1f4b2007-12-06 10:55:25 -0500202
Matthew Wilcoxf021a3c2007-12-06 11:13:16 -0500203#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
204#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
Matthew Wilcox92a1f4b2007-12-06 10:55:25 -0500205#define task_is_stopped_or_traced(task) \
Matthew Wilcoxf021a3c2007-12-06 11:13:16 -0500206 ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
Matthew Wilcox92a1f4b2007-12-06 10:55:25 -0500207#define task_contributes_to_load(task) \
208 ((task->state & TASK_UNINTERRUPTIBLE) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210#define __set_task_state(tsk, state_value) \
211 do { (tsk)->state = (state_value); } while (0)
212#define set_task_state(tsk, state_value) \
213 set_mb((tsk)->state, (state_value))
214
Andrew Morton498d0c52005-09-13 01:25:14 -0700215/*
216 * set_current_state() includes a barrier so that the write of current->state
217 * is correctly serialised wrt the caller's subsequent test of whether to
218 * actually sleep:
219 *
220 * set_current_state(TASK_UNINTERRUPTIBLE);
221 * if (do_i_need_to_sleep())
222 * schedule();
223 *
224 * If the caller does not need such serialisation then use __set_current_state()
225 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226#define __set_current_state(state_value) \
227 do { current->state = (state_value); } while (0)
228#define set_current_state(state_value) \
229 set_mb(current->state, (state_value))
230
231/* Task command name length */
232#define TASK_COMM_LEN 16
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234#include <linux/spinlock.h>
235
236/*
237 * This serializes "schedule()" and also protects
238 * the run-queue from deletions/modifications (but
239 * _adding_ to the beginning of the run-queue has
240 * a separate lock).
241 */
242extern rwlock_t tasklist_lock;
243extern spinlock_t mmlist_lock;
244
Ingo Molnar36c8b582006-07-03 00:25:41 -0700245struct task_struct;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247extern void sched_init(void);
248extern void sched_init_smp(void);
Harvey Harrison2d07b252008-02-15 09:56:34 -0800249extern asmlinkage void schedule_tail(struct task_struct *prev);
Ingo Molnar36c8b582006-07-03 00:25:41 -0700250extern void init_idle(struct task_struct *idle, int cpu);
Ingo Molnar1df21052007-07-09 18:51:58 +0200251extern void init_idle_bootup_task(struct task_struct *idle);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Ingo Molnar017730c2008-05-12 21:20:52 +0200253extern int runqueue_is_locked(void);
Oleg Nesterovad474ca2008-11-10 15:39:30 +0100254extern void task_rq_unlock_wait(struct task_struct *p);
Ingo Molnar017730c2008-05-12 21:20:52 +0200255
Rusty Russell6a7b3dc2008-11-25 02:35:04 +1030256extern cpumask_var_t nohz_cpu_mask;
Siddha, Suresh B46cb4b72007-05-08 00:32:51 -0700257#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
258extern int select_nohz_load_balancer(int cpu);
259#else
260static inline int select_nohz_load_balancer(int cpu)
261{
262 return 0;
263}
264#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
Ingo Molnare59e2ae2006-12-06 20:35:59 -0800266/*
Ingo Molnar39bc89f2007-04-25 20:50:03 -0700267 * Only dump TASK_* tasks. (0 for all tasks)
Ingo Molnare59e2ae2006-12-06 20:35:59 -0800268 */
269extern void show_state_filter(unsigned long state_filter);
270
271static inline void show_state(void)
272{
Ingo Molnar39bc89f2007-04-25 20:50:03 -0700273 show_state_filter(0);
Ingo Molnare59e2ae2006-12-06 20:35:59 -0800274}
275
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276extern void show_regs(struct pt_regs *);
277
278/*
279 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
280 * task), SP is the stack pointer of the first frame that should be shown in the back
281 * trace (or NULL if the entire call-chain of the task should be shown).
282 */
283extern void show_stack(struct task_struct *task, unsigned long *sp);
284
285void io_schedule(void);
286long io_schedule_timeout(long timeout);
287
288extern void cpu_init (void);
289extern void trap_init(void);
290extern void update_process_times(int user);
291extern void scheduler_tick(void);
292
Ingo Molnar82a1fcb2008-01-25 21:08:02 +0100293extern void sched_show_task(struct task_struct *p);
294
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700295#ifdef CONFIG_DETECT_SOFTLOCKUP
Ingo Molnar6687a972006-03-24 03:18:41 -0800296extern void softlockup_tick(void);
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700297extern void touch_softlockup_watchdog(void);
Jeremy Fitzhardinge04c91672007-05-08 00:28:05 -0700298extern void touch_all_softlockup_watchdogs(void);
Mandeep Singh Bainesbaf48f62009-01-12 21:15:17 -0800299extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
300 struct file *filp, void __user *buffer,
301 size_t *lenp, loff_t *ppos);
Ingo Molnar9c44bc02008-05-12 21:21:04 +0200302extern unsigned int softlockup_panic;
Ingo Molnar82a1fcb2008-01-25 21:08:02 +0100303extern unsigned long sysctl_hung_task_check_count;
304extern unsigned long sysctl_hung_task_timeout_secs;
Ingo Molnar90739082008-01-25 21:08:34 +0100305extern unsigned long sysctl_hung_task_warnings;
Dimitri Sivanich9383d962008-05-12 21:21:14 +0200306extern int softlockup_thresh;
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700307#else
Ingo Molnar6687a972006-03-24 03:18:41 -0800308static inline void softlockup_tick(void)
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700309{
310}
311static inline void spawn_softlockup_task(void)
312{
313}
314static inline void touch_softlockup_watchdog(void)
315{
316}
Jeremy Fitzhardinge04c91672007-05-08 00:28:05 -0700317static inline void touch_all_softlockup_watchdogs(void)
318{
319}
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700320#endif
321
322
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323/* Attach to any functions which should be ignored in wchan output. */
324#define __sched __attribute__((__section__(".sched.text")))
Ingo Molnardeaf2222007-11-28 15:52:56 +0100325
326/* Linker adds these: start and end of __sched functions */
327extern char __sched_text_start[], __sched_text_end[];
328
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329/* Is this address in the __sched functions? */
330extern int in_sched_functions(unsigned long addr);
331
332#define MAX_SCHEDULE_TIMEOUT LONG_MAX
Harvey Harrisonb3c97522008-02-13 15:03:15 -0800333extern signed long schedule_timeout(signed long timeout);
Nishanth Aravamudan64ed93a2005-09-10 00:27:21 -0700334extern signed long schedule_timeout_interruptible(signed long timeout);
Matthew Wilcox294d5cc2007-12-06 11:59:46 -0500335extern signed long schedule_timeout_killable(signed long timeout);
Nishanth Aravamudan64ed93a2005-09-10 00:27:21 -0700336extern signed long schedule_timeout_uninterruptible(signed long timeout);
Peter Zijlstra41719b02009-01-14 15:36:26 +0100337asmlinkage void __schedule(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338asmlinkage void schedule(void);
Peter Zijlstra0d66bf62009-01-12 14:01:47 +0100339extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
Serge E. Hallynab516012006-10-02 02:18:06 -0700341struct nsproxy;
Cedric Le Goateracce2922007-07-15 23:40:59 -0700342struct user_namespace;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343
344/* Maximum number of active map areas.. This is a random (large) number */
345#define DEFAULT_MAX_MAP_COUNT 65536
346
347extern int sysctl_max_map_count;
348
349#include <linux/aio.h>
350
351extern unsigned long
352arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
353 unsigned long, unsigned long);
354extern unsigned long
355arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
356 unsigned long len, unsigned long pgoff,
357 unsigned long flags);
Wolfgang Wander1363c3c2005-06-21 17:14:49 -0700358extern void arch_unmap_area(struct mm_struct *, unsigned long);
359extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
Jeremy Fitzhardingef7d0b922008-09-09 15:43:22 -0700361#if USE_SPLIT_PTLOCKS
Hugh Dickinsf412ac02005-10-29 18:16:41 -0700362/*
363 * The mm counters are not protected by its page_table_lock,
364 * so must be incremented atomically.
365 */
Christoph Lameterd3cb4872006-01-06 00:11:20 -0800366#define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
367#define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
368#define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
369#define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
370#define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
Hugh Dickinsf412ac02005-10-29 18:16:41 -0700371
Jeremy Fitzhardingef7d0b922008-09-09 15:43:22 -0700372#else /* !USE_SPLIT_PTLOCKS */
Hugh Dickinsf412ac02005-10-29 18:16:41 -0700373/*
374 * The mm counters are protected by its page_table_lock,
375 * so can be incremented directly.
376 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377#define set_mm_counter(mm, member, value) (mm)->_##member = (value)
378#define get_mm_counter(mm, member) ((mm)->_##member)
379#define add_mm_counter(mm, member, value) (mm)->_##member += (value)
380#define inc_mm_counter(mm, member) (mm)->_##member++
381#define dec_mm_counter(mm, member) (mm)->_##member--
Hugh Dickins42946212005-10-29 18:16:05 -0700382
Jeremy Fitzhardingef7d0b922008-09-09 15:43:22 -0700383#endif /* !USE_SPLIT_PTLOCKS */
Hugh Dickinsf412ac02005-10-29 18:16:41 -0700384
385#define get_mm_rss(mm) \
386 (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
Hugh Dickins365e9c872005-10-29 18:16:18 -0700387#define update_hiwater_rss(mm) do { \
388 unsigned long _rss = get_mm_rss(mm); \
389 if ((mm)->hiwater_rss < _rss) \
390 (mm)->hiwater_rss = _rss; \
391} while (0)
392#define update_hiwater_vm(mm) do { \
393 if ((mm)->hiwater_vm < (mm)->total_vm) \
394 (mm)->hiwater_vm = (mm)->total_vm; \
395} while (0)
396
Oleg Nesterov9de15812009-03-31 15:19:29 -0700397static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
398{
399 return max(mm->hiwater_rss, get_mm_rss(mm));
400}
401
402static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
403{
404 return max(mm->hiwater_vm, mm->total_vm);
405}
Oleg Nesterov901608d2009-01-06 14:40:29 -0800406
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700407extern void set_dumpable(struct mm_struct *mm, int value);
408extern int get_dumpable(struct mm_struct *mm);
409
410/* mm flags */
Kawai, Hidehiro3cb4a0b2007-07-19 01:48:28 -0700411/* dumpable bits */
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700412#define MMF_DUMPABLE 0 /* core dump is permitted */
413#define MMF_DUMP_SECURELY 1 /* core file is readable only by root */
Kawai, Hidehiro3cb4a0b2007-07-19 01:48:28 -0700414#define MMF_DUMPABLE_BITS 2
415
416/* coredump filter bits */
417#define MMF_DUMP_ANON_PRIVATE 2
418#define MMF_DUMP_ANON_SHARED 3
419#define MMF_DUMP_MAPPED_PRIVATE 4
420#define MMF_DUMP_MAPPED_SHARED 5
Roland McGrath82df3972007-10-16 23:27:02 -0700421#define MMF_DUMP_ELF_HEADERS 6
KOSAKI Motohiroe575f112008-10-18 20:27:08 -0700422#define MMF_DUMP_HUGETLB_PRIVATE 7
423#define MMF_DUMP_HUGETLB_SHARED 8
Kawai, Hidehiro3cb4a0b2007-07-19 01:48:28 -0700424#define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS
KOSAKI Motohiroe575f112008-10-18 20:27:08 -0700425#define MMF_DUMP_FILTER_BITS 7
Kawai, Hidehiro3cb4a0b2007-07-19 01:48:28 -0700426#define MMF_DUMP_FILTER_MASK \
427 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
428#define MMF_DUMP_FILTER_DEFAULT \
KOSAKI Motohiroe575f112008-10-18 20:27:08 -0700429 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
Roland McGrath656eb2c2008-10-18 20:28:23 -0700430 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
431
432#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
433# define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS)
434#else
435# define MMF_DUMP_MASK_DEFAULT_ELF 0
436#endif
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438struct sighand_struct {
439 atomic_t count;
440 struct k_sigaction action[_NSIG];
441 spinlock_t siglock;
Davide Libenzib8fceee2007-09-20 12:40:16 -0700442 wait_queue_head_t signalfd_wqh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443};
444
KaiGai Kohei0e464812006-06-25 05:49:24 -0700445struct pacct_struct {
KaiGai Koheif6ec29a2006-06-25 05:49:25 -0700446 int ac_flag;
447 long ac_exitcode;
KaiGai Kohei0e464812006-06-25 05:49:24 -0700448 unsigned long ac_mem;
KaiGai Kohei77787bf2006-06-25 05:49:26 -0700449 cputime_t ac_utime, ac_stime;
450 unsigned long ac_minflt, ac_majflt;
KaiGai Kohei0e464812006-06-25 05:49:24 -0700451};
452
Frank Mayharf06febc2008-09-12 09:54:39 -0700453/**
454 * struct task_cputime - collected CPU time counts
455 * @utime: time spent in user mode, in &cputime_t units
456 * @stime: time spent in kernel mode, in &cputime_t units
457 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
Ingo Molnar5ce73a42008-09-14 17:11:46 +0200458 *
Frank Mayharf06febc2008-09-12 09:54:39 -0700459 * This structure groups together three kinds of CPU time that are
460 * tracked for threads and thread groups. Most things considering
461 * CPU time want to group these counts together and treat all three
462 * of them in parallel.
463 */
464struct task_cputime {
465 cputime_t utime;
466 cputime_t stime;
467 unsigned long long sum_exec_runtime;
468};
469/* Alternate field names when used to cache expirations. */
470#define prof_exp stime
471#define virt_exp utime
472#define sched_exp sum_exec_runtime
473
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100474#define INIT_CPUTIME \
475 (struct task_cputime) { \
476 .utime = cputime_zero, \
477 .stime = cputime_zero, \
478 .sum_exec_runtime = 0, \
479 }
480
Frank Mayharf06febc2008-09-12 09:54:39 -0700481/**
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100482 * struct thread_group_cputimer - thread group interval timer counts
483 * @cputime: thread group interval timers.
484 * @running: non-zero when there are timers running and
485 * @cputime receives updates.
486 * @lock: lock for fields in this struct.
Frank Mayharf06febc2008-09-12 09:54:39 -0700487 *
488 * This structure contains the version of task_cputime, above, that is
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100489 * used for thread group CPU timer calculations.
Frank Mayharf06febc2008-09-12 09:54:39 -0700490 */
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100491struct thread_group_cputimer {
492 struct task_cputime cputime;
493 int running;
494 spinlock_t lock;
Frank Mayharf06febc2008-09-12 09:54:39 -0700495};
Frank Mayharf06febc2008-09-12 09:54:39 -0700496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497/*
498 * NOTE! "signal_struct" does not have it's own
499 * locking, because a shared signal_struct always
500 * implies a shared sighand_struct, so locking
501 * sighand_struct is always a proper superset of
502 * the locking of signal_struct.
503 */
504struct signal_struct {
505 atomic_t count;
506 atomic_t live;
507
508 wait_queue_head_t wait_chldexit; /* for wait4() */
509
510 /* current thread group signal load-balancing target: */
Ingo Molnar36c8b582006-07-03 00:25:41 -0700511 struct task_struct *curr_target;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
513 /* shared signal handling: */
514 struct sigpending shared_pending;
515
516 /* thread group exit support */
517 int group_exit_code;
518 /* overloaded:
519 * - notify group_exit_task when ->count is equal to notify_count
520 * - everyone except group_exit_task is stopped during signal delivery
521 * of fatal signals, group_exit_task processes the signal.
522 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 int notify_count;
Richard Kennedy07dd20e2008-08-01 13:18:04 +0100524 struct task_struct *group_exit_task;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525
526 /* thread group stop support, overloads group_exit_code too */
527 int group_stop_count;
528 unsigned int flags; /* see SIGNAL_* flags below */
529
530 /* POSIX.1b Interval Timers */
531 struct list_head posix_timers;
532
533 /* ITIMER_REAL timer for the process */
Thomas Gleixner2ff678b2006-01-09 20:52:34 -0800534 struct hrtimer real_timer;
Oleg Nesterovfea9d172008-02-08 04:19:19 -0800535 struct pid *leader_pid;
Thomas Gleixner2ff678b2006-01-09 20:52:34 -0800536 ktime_t it_real_incr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
538 /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
539 cputime_t it_prof_expires, it_virt_expires;
540 cputime_t it_prof_incr, it_virt_incr;
541
Frank Mayharf06febc2008-09-12 09:54:39 -0700542 /*
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100543 * Thread group totals for process CPU timers.
544 * See thread_group_cputimer(), et al, for details.
Frank Mayharf06febc2008-09-12 09:54:39 -0700545 */
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +0100546 struct thread_group_cputimer cputimer;
Frank Mayharf06febc2008-09-12 09:54:39 -0700547
548 /* Earliest-expiration cache. */
549 struct task_cputime cputime_expires;
550
551 struct list_head cpu_timers[3];
552
Eric W. Biedermanab521dc2007-02-12 00:53:00 -0800553 struct pid *tty_old_pgrp;
Cedric Le Goater1ec320a2006-12-08 02:37:55 -0800554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 /* boolean value for session group leader */
556 int leader;
557
558 struct tty_struct *tty; /* NULL if no tty */
559
560 /*
561 * Cumulative resource counters for dead threads in the group,
562 * and for reaped dead child processes forked by this group.
563 * Live threads maintain their own counters and add to these
564 * in __exit_signal, except for the group leader.
565 */
Peter Zijlstra32bd6712009-02-05 12:24:15 +0100566 cputime_t utime, stime, cutime, cstime;
Laurent Vivier9ac52312007-10-15 17:00:19 +0200567 cputime_t gtime;
568 cputime_t cgtime;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
570 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
Eric Dumazet6eaeeab2007-05-10 22:22:37 -0700571 unsigned long inblock, oublock, cinblock, coublock;
Andrea Righi940389b2008-07-28 00:48:12 +0200572 struct task_io_accounting ioac;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
574 /*
Peter Zijlstra32bd6712009-02-05 12:24:15 +0100575 * Cumulative ns of schedule CPU time fo dead threads in the
576 * group, not including a zombie group leader, (This only differs
577 * from jiffies_to_ns(utime + stime) if sched_clock uses something
578 * other than jiffies.)
579 */
580 unsigned long long sum_sched_runtime;
581
582 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 * We don't bother to synchronize most readers of this at all,
584 * because there is no reader checking a limit that actually needs
585 * to get both rlim_cur and rlim_max atomically, and either one
586 * alone is a single word that can safely be read normally.
587 * getrlimit/setrlimit use task_lock(current->group_leader) to
588 * protect this instead of the siglock, because they really
589 * have no need to disable irqs.
590 */
591 struct rlimit rlim[RLIM_NLIMITS];
592
KaiGai Kohei0e464812006-06-25 05:49:24 -0700593#ifdef CONFIG_BSD_PROCESS_ACCT
594 struct pacct_struct pacct; /* per-process accounting information */
595#endif
Shailabh Nagarad4ecbc2006-07-14 00:24:44 -0700596#ifdef CONFIG_TASKSTATS
Shailabh Nagarad4ecbc2006-07-14 00:24:44 -0700597 struct taskstats *stats;
598#endif
Miloslav Trmac522ed772007-07-15 23:40:56 -0700599#ifdef CONFIG_AUDIT
600 unsigned audit_tty;
601 struct tty_audit_buf *tty_audit_buf;
602#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603};
604
Nick Piggin4866cde2005-06-25 14:57:23 -0700605/* Context switch must be unlocked if interrupts are to be enabled */
606#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
607# define __ARCH_WANT_UNLOCKED_CTXSW
608#endif
609
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610/*
611 * Bits in flags field of signal_struct.
612 */
613#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
614#define SIGNAL_STOP_DEQUEUED 0x00000002 /* stop signal dequeued */
615#define SIGNAL_STOP_CONTINUED 0x00000004 /* SIGCONT since WCONTINUED reap */
616#define SIGNAL_GROUP_EXIT 0x00000008 /* group exit in progress */
Oleg Nesterove4420552008-04-30 00:52:44 -0700617/*
618 * Pending notifications to parent.
619 */
620#define SIGNAL_CLD_STOPPED 0x00000010
621#define SIGNAL_CLD_CONTINUED 0x00000020
622#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700624#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
625
Oleg Nesteroved5d2ca2008-02-04 22:27:24 -0800626/* If true, all threads except ->group_exit_task have pending SIGKILL */
627static inline int signal_group_exit(const struct signal_struct *sig)
628{
629 return (sig->flags & SIGNAL_GROUP_EXIT) ||
630 (sig->group_exit_task != NULL);
631}
632
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633/*
634 * Some day this will be a full-fledged user tracking system..
635 */
636struct user_struct {
637 atomic_t __count; /* reference count */
638 atomic_t processes; /* How many processes does this user have? */
639 atomic_t files; /* How many open files does this user have? */
640 atomic_t sigpending; /* How many pending signals does this user have? */
Amy Griffis2d9048e2006-06-01 13:10:59 -0700641#ifdef CONFIG_INOTIFY_USER
Robert Love0eeca282005-07-12 17:06:03 -0400642 atomic_t inotify_watches; /* How many inotify watches does this user have? */
643 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
644#endif
Davide Libenzi7ef99642008-12-01 13:13:55 -0800645#ifdef CONFIG_EPOLL
Davide Libenzi7ef99642008-12-01 13:13:55 -0800646 atomic_t epoll_watches; /* The number of file descriptors currently watched */
647#endif
Alexey Dobriyan970a8642007-10-16 23:30:09 -0700648#ifdef CONFIG_POSIX_MQUEUE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 /* protected by mq_lock */
650 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
Alexey Dobriyan970a8642007-10-16 23:30:09 -0700651#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 unsigned long locked_shm; /* How many pages of mlocked shm ? */
653
654#ifdef CONFIG_KEYS
655 struct key *uid_keyring; /* UID specific keyring */
656 struct key *session_keyring; /* UID's default session keyring */
657#endif
658
659 /* Hash table maintenance information */
Pavel Emelyanov735de222007-09-18 22:46:44 -0700660 struct hlist_node uidhash_node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 uid_t uid;
Serge Hallyn18b6e042008-10-15 16:38:45 -0500662 struct user_namespace *user_ns;
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200663
Peter Zijlstra052f1dc2008-02-13 15:45:40 +0100664#ifdef CONFIG_USER_SCHED
Ingo Molnar4cf86d72007-10-15 17:00:14 +0200665 struct task_group *tg;
Dhaval Gianib1a8c172007-10-17 16:55:11 +0200666#ifdef CONFIG_SYSFS
Kay Sieverseb41d942007-11-02 13:47:53 +0100667 struct kobject kobj;
Dhaval Giani5cb350b2007-10-15 17:00:14 +0200668 struct work_struct work;
Srivatsa Vaddagiri24e377a2007-10-15 17:00:09 +0200669#endif
Dhaval Gianib1a8c172007-10-17 16:55:11 +0200670#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671};
672
Kay Sieverseb41d942007-11-02 13:47:53 +0100673extern int uids_sysfs_init(void);
Dhaval Giani5cb350b2007-10-15 17:00:14 +0200674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675extern struct user_struct *find_user(uid_t);
676
677extern struct user_struct root_user;
678#define INIT_USER (&root_user)
679
David Howellsb6dff3e2008-11-14 10:39:16 +1100680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681struct backing_dev_info;
682struct reclaim_state;
683
Chandra Seetharaman52f17b62006-07-14 00:24:38 -0700684#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685struct sched_info {
686 /* cumulative counters */
Ingo Molnar2d723762007-10-15 17:00:12 +0200687 unsigned long pcount; /* # of times run on this cpu */
Ken Chen9c2c4802008-12-16 23:41:22 -0800688 unsigned long long run_delay; /* time spent waiting on a runqueue */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
690 /* timestamps */
Balbir Singh172ba842007-07-09 18:52:00 +0200691 unsigned long long last_arrival,/* when we last ran on a cpu */
692 last_queued; /* when we were last queued to run */
Ingo Molnarb8efb562007-10-15 17:00:10 +0200693#ifdef CONFIG_SCHEDSTATS
694 /* BKL stats */
Ken Chen480b9432007-10-18 21:32:56 +0200695 unsigned int bkl_count;
Ingo Molnarb8efb562007-10-15 17:00:10 +0200696#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697};
Chandra Seetharaman52f17b62006-07-14 00:24:38 -0700698#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699
Shailabh Nagarca74e922006-07-14 00:24:36 -0700700#ifdef CONFIG_TASK_DELAY_ACCT
701struct task_delay_info {
702 spinlock_t lock;
703 unsigned int flags; /* Private per-task flags */
704
705 /* For each stat XXX, add following, aligned appropriately
706 *
707 * struct timespec XXX_start, XXX_end;
708 * u64 XXX_delay;
709 * u32 XXX_count;
710 *
711 * Atomicity of updates to XXX_delay, XXX_count protected by
712 * single lock above (split into XXX_lock if contention is an issue).
713 */
Shailabh Nagar0ff92242006-07-14 00:24:37 -0700714
715 /*
716 * XXX_count is incremented on every XXX operation, the delay
717 * associated with the operation is added to XXX_delay.
718 * XXX_delay contains the accumulated delay time in nanoseconds.
719 */
720 struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
721 u64 blkio_delay; /* wait for sync block io completion */
722 u64 swapin_delay; /* wait for swapin block io completion */
723 u32 blkio_count; /* total count of the number of sync block */
724 /* io operations performed */
725 u32 swapin_count; /* total count of the number of swapin block */
726 /* io operations performed */
Keika Kobayashi873b4772008-07-25 01:48:52 -0700727
728 struct timespec freepages_start, freepages_end;
729 u64 freepages_delay; /* wait for memory reclaim */
730 u32 freepages_count; /* total count of memory reclaim */
Shailabh Nagarca74e922006-07-14 00:24:36 -0700731};
Chandra Seetharaman52f17b62006-07-14 00:24:38 -0700732#endif /* CONFIG_TASK_DELAY_ACCT */
733
734static inline int sched_info_on(void)
735{
736#ifdef CONFIG_SCHEDSTATS
737 return 1;
738#elif defined(CONFIG_TASK_DELAY_ACCT)
739 extern int delayacct_on;
740 return delayacct_on;
741#else
742 return 0;
Shailabh Nagarca74e922006-07-14 00:24:36 -0700743#endif
Chandra Seetharaman52f17b62006-07-14 00:24:38 -0700744}
Shailabh Nagarca74e922006-07-14 00:24:36 -0700745
Ingo Molnard15bcfd2007-07-09 18:51:57 +0200746enum cpu_idle_type {
747 CPU_IDLE,
748 CPU_NOT_IDLE,
749 CPU_NEWLY_IDLE,
750 CPU_MAX_IDLE_TYPES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751};
752
753/*
754 * sched-domains (multiprocessor balancing) declarations:
755 */
Ingo Molnar9aa7b362007-07-09 18:51:58 +0200756
757/*
758 * Increase resolution of nice-level calculations:
759 */
760#define SCHED_LOAD_SHIFT 10
761#define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
762
Suresh Siddhaf8700df2007-08-23 15:18:02 +0200763#define SCHED_LOAD_SCALE_FUZZ SCHED_LOAD_SCALE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764
Peter Williams2dd73a42006-06-27 02:54:34 -0700765#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766#define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */
767#define SD_BALANCE_NEWIDLE 2 /* Balance when about to become idle */
768#define SD_BALANCE_EXEC 4 /* Balance on exec */
Nick Piggin147cbb42005-06-25 14:57:19 -0700769#define SD_BALANCE_FORK 8 /* Balance on fork, clone */
770#define SD_WAKE_IDLE 16 /* Wake to idle CPU on task wakeup */
771#define SD_WAKE_AFFINE 32 /* Wake task to waking CPU */
772#define SD_WAKE_BALANCE 64 /* Perform balancing at task wakeup */
773#define SD_SHARE_CPUPOWER 128 /* Domain members share cpu power */
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -0700774#define SD_POWERSAVINGS_BALANCE 256 /* Balance for power savings */
Siddha, Suresh B89c47102006-10-03 01:14:09 -0700775#define SD_SHARE_PKG_RESOURCES 512 /* Domain members share cpu pkg resources */
Christoph Lameter08c183f2006-12-10 02:20:29 -0800776#define SD_SERIALIZE 1024 /* Only a single load balancing instance */
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +0900777#define SD_WAKE_IDLE_FAR 2048 /* Gain latency sacrificing cache hit */
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -0700778
Gautham R Shenoyafb8a9b2008-12-18 23:26:09 +0530779enum powersavings_balance_level {
780 POWERSAVINGS_BALANCE_NONE = 0, /* No power saving load balance */
781 POWERSAVINGS_BALANCE_BASIC, /* Fill one thread/core/package
782 * first for long running threads
783 */
784 POWERSAVINGS_BALANCE_WAKEUP, /* Also bias task wakeups to semi-idle
785 * cpu package for power savings
786 */
787 MAX_POWERSAVINGS_BALANCE_LEVELS
788};
Siddha, Suresh B89c47102006-10-03 01:14:09 -0700789
Vaidyanathan Srinivasan716707b2008-12-18 23:26:02 +0530790extern int sched_mc_power_savings, sched_smt_power_savings;
Siddha, Suresh B89c47102006-10-03 01:14:09 -0700791
Vaidyanathan Srinivasan716707b2008-12-18 23:26:02 +0530792static inline int sd_balance_for_mc_power(void)
793{
794 if (sched_smt_power_savings)
795 return SD_POWERSAVINGS_BALANCE;
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -0700796
Vaidyanathan Srinivasan716707b2008-12-18 23:26:02 +0530797 return 0;
798}
799
800static inline int sd_balance_for_package_power(void)
801{
802 if (sched_mc_power_savings | sched_smt_power_savings)
803 return SD_POWERSAVINGS_BALANCE;
804
805 return 0;
806}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807
Vaidyanathan Srinivasan100fdae2008-12-18 23:26:47 +0530808/*
809 * Optimise SD flags for power savings:
810 * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings.
811 * Keep default SD flags if sched_{smt,mc}_power_saving=0
812 */
813
814static inline int sd_power_saving_flags(void)
815{
816 if (sched_mc_power_savings | sched_smt_power_savings)
817 return SD_BALANCE_NEWIDLE;
818
819 return 0;
820}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821
822struct sched_group {
823 struct sched_group *next; /* Must be a circular list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
825 /*
826 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
827 * single CPU. This is read only (except for setup, hotplug CPU).
Eric Dumazet5517d862007-05-08 00:32:57 -0700828 * Note : Never change cpu_power without recompute its reciprocal
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 */
Eric Dumazet5517d862007-05-08 00:32:57 -0700830 unsigned int __cpu_power;
831 /*
832 * reciprocal value of cpu_power to avoid expensive divides
833 * (see include/linux/reciprocal_div.h)
834 */
835 u32 reciprocal_cpu_power;
Rusty Russell6c99e9a2008-11-25 02:35:04 +1030836
837 unsigned long cpumask[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838};
839
Rusty Russell758b2cd2008-11-25 02:35:04 +1030840static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
841{
Rusty Russell6c99e9a2008-11-25 02:35:04 +1030842 return to_cpumask(sg->cpumask);
Rusty Russell758b2cd2008-11-25 02:35:04 +1030843}
844
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +0900845enum sched_domain_level {
846 SD_LV_NONE = 0,
847 SD_LV_SIBLING,
848 SD_LV_MC,
849 SD_LV_CPU,
850 SD_LV_NODE,
851 SD_LV_ALLNODES,
852 SD_LV_MAX
853};
854
855struct sched_domain_attr {
856 int relax_domain_level;
857};
858
859#define SD_ATTR_INIT (struct sched_domain_attr) { \
860 .relax_domain_level = -1, \
861}
862
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863struct sched_domain {
864 /* These fields must be setup */
865 struct sched_domain *parent; /* top domain must be null terminated */
Siddha, Suresh B1a848872006-10-03 01:14:08 -0700866 struct sched_domain *child; /* bottom domain must be null terminated */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 struct sched_group *groups; /* the balancing groups of the domain */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 unsigned long min_interval; /* Minimum balance interval ms */
869 unsigned long max_interval; /* Maximum balance interval ms */
870 unsigned int busy_factor; /* less balancing by factor if busy */
871 unsigned int imbalance_pct; /* No balance until over watermark */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
Nick Piggin78979862005-06-25 14:57:13 -0700873 unsigned int busy_idx;
874 unsigned int idle_idx;
875 unsigned int newidle_idx;
876 unsigned int wake_idx;
Nick Piggin147cbb42005-06-25 14:57:19 -0700877 unsigned int forkexec_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 int flags; /* See SD_* */
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +0900879 enum sched_domain_level level;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
881 /* Runtime fields. */
882 unsigned long last_balance; /* init to jiffies. units in jiffies */
883 unsigned int balance_interval; /* initialise to 1. units in ms. */
884 unsigned int nr_balance_failed; /* initialise to 0 */
885
Peter Zijlstra2398f2c2008-06-27 13:41:35 +0200886 u64 last_update;
887
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888#ifdef CONFIG_SCHEDSTATS
889 /* load_balance() stats */
Ken Chen480b9432007-10-18 21:32:56 +0200890 unsigned int lb_count[CPU_MAX_IDLE_TYPES];
891 unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
892 unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
893 unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
894 unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
895 unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
896 unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
897 unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 /* Active load balancing */
Ken Chen480b9432007-10-18 21:32:56 +0200900 unsigned int alb_count;
901 unsigned int alb_failed;
902 unsigned int alb_pushed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
Nick Piggin68767a02005-06-25 14:57:20 -0700904 /* SD_BALANCE_EXEC stats */
Ken Chen480b9432007-10-18 21:32:56 +0200905 unsigned int sbe_count;
906 unsigned int sbe_balanced;
907 unsigned int sbe_pushed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
Nick Piggin68767a02005-06-25 14:57:20 -0700909 /* SD_BALANCE_FORK stats */
Ken Chen480b9432007-10-18 21:32:56 +0200910 unsigned int sbf_count;
911 unsigned int sbf_balanced;
912 unsigned int sbf_pushed;
Nick Piggin68767a02005-06-25 14:57:20 -0700913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 /* try_to_wake_up() stats */
Ken Chen480b9432007-10-18 21:32:56 +0200915 unsigned int ttwu_wake_remote;
916 unsigned int ttwu_move_affine;
917 unsigned int ttwu_move_balance;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918#endif
Ingo Molnara5d8c342008-10-09 11:35:51 +0200919#ifdef CONFIG_SCHED_DEBUG
920 char *name;
921#endif
Rusty Russell6c99e9a2008-11-25 02:35:04 +1030922
923 /* span of all CPUs in this domain */
924 unsigned long span[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925};
926
Rusty Russell758b2cd2008-11-25 02:35:04 +1030927static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
928{
Rusty Russell6c99e9a2008-11-25 02:35:04 +1030929 return to_cpumask(sd->span);
Rusty Russell758b2cd2008-11-25 02:35:04 +1030930}
931
Rusty Russell96f874e2008-11-25 02:35:14 +1030932extern void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
Hidetoshi Seto1d3504f2008-04-15 14:04:23 +0900933 struct sched_domain_attr *dattr_new);
Paul Jackson029190c2007-10-18 23:40:20 -0700934
Ingo Molnar06aaf762008-12-18 21:30:23 +0100935/* Test a flag in parent sched domain */
936static inline int test_sd_parent(struct sched_domain *sd, int flag)
937{
938 if (sd->parent && (sd->parent->flags & flag))
939 return 1;
940
941 return 0;
942}
943
Ingo Molnar1b427c12008-07-18 14:01:39 +0200944#else /* CONFIG_SMP */
945
946struct sched_domain_attr;
947
948static inline void
Rusty Russell96f874e2008-11-25 02:35:14 +1030949partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
Ingo Molnar1b427c12008-07-18 14:01:39 +0200950 struct sched_domain_attr *dattr_new)
951{
952}
953#endif /* !CONFIG_SMP */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955struct io_context; /* See blkdev.h */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957
Chen, Kenneth W383f2832005-09-09 13:02:02 -0700958#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
Ingo Molnar36c8b582006-07-03 00:25:41 -0700959extern void prefetch_stack(struct task_struct *t);
Chen, Kenneth W383f2832005-09-09 13:02:02 -0700960#else
961static inline void prefetch_stack(struct task_struct *t) { }
962#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963
964struct audit_context; /* See audit.c */
965struct mempolicy;
Jens Axboeb92ce552006-04-11 13:52:07 +0200966struct pipe_inode_info;
Serge E. Hallyn4865ecf2006-10-02 02:18:14 -0700967struct uts_namespace;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Ingo Molnar20b8a592007-07-09 18:51:58 +0200969struct rq;
970struct sched_domain;
971
972struct sched_class {
Ingo Molnar5522d5d2007-10-15 17:00:12 +0200973 const struct sched_class *next;
Ingo Molnar20b8a592007-07-09 18:51:58 +0200974
Ingo Molnarfd390f62007-08-09 11:16:48 +0200975 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
Ingo Molnarf02231e2007-08-09 11:16:48 +0200976 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
Dmitry Adamushko4530d7a2007-10-15 17:00:08 +0200977 void (*yield_task) (struct rq *rq);
Ingo Molnar20b8a592007-07-09 18:51:58 +0200978
Peter Zijlstra15afe092008-09-20 23:38:02 +0200979 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync);
Ingo Molnar20b8a592007-07-09 18:51:58 +0200980
Ingo Molnarfb8d4722007-08-09 11:16:48 +0200981 struct task_struct * (*pick_next_task) (struct rq *rq);
Ingo Molnar31ee5292007-08-09 11:16:49 +0200982 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
Ingo Molnar20b8a592007-07-09 18:51:58 +0200983
Peter Williams681f3e62007-10-24 18:23:51 +0200984#ifdef CONFIG_SMP
Li Zefan4ce72a22008-10-22 15:25:26 +0800985 int (*select_task_rq)(struct task_struct *p, int sync);
986
Peter Williams43010652007-08-09 11:16:46 +0200987 unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
Peter Williamse1d14842007-10-24 18:23:51 +0200988 struct rq *busiest, unsigned long max_load_move,
Ingo Molnar20b8a592007-07-09 18:51:58 +0200989 struct sched_domain *sd, enum cpu_idle_type idle,
Peter Williamsa4ac01c2007-08-09 11:16:46 +0200990 int *all_pinned, int *this_best_prio);
Ingo Molnar20b8a592007-07-09 18:51:58 +0200991
Peter Williamse1d14842007-10-24 18:23:51 +0200992 int (*move_one_task) (struct rq *this_rq, int this_cpu,
993 struct rq *busiest, struct sched_domain *sd,
994 enum cpu_idle_type idle);
Steven Rostedt9a897c52008-01-25 21:08:22 +0100995 void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
Gregory Haskins967fc042008-12-29 09:39:52 -0500996 int (*needs_post_schedule) (struct rq *this_rq);
Steven Rostedt9a897c52008-01-25 21:08:22 +0100997 void (*post_schedule) (struct rq *this_rq);
998 void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
Peter Williamse1d14842007-10-24 18:23:51 +0200999
Mike Traviscd8ba7c2008-03-26 14:23:49 -07001000 void (*set_cpus_allowed)(struct task_struct *p,
Rusty Russell96f874e2008-11-25 02:35:14 +10301001 const struct cpumask *newmask);
Gregory Haskins57d885f2008-01-25 21:08:18 +01001002
Gregory Haskins1f11eb62008-06-04 15:04:05 -04001003 void (*rq_online)(struct rq *rq);
1004 void (*rq_offline)(struct rq *rq);
Li Zefan4ce72a22008-10-22 15:25:26 +08001005#endif
1006
1007 void (*set_curr_task) (struct rq *rq);
1008 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1009 void (*task_new) (struct rq *rq, struct task_struct *p);
Steven Rostedtcb469842008-01-25 21:08:22 +01001010
1011 void (*switched_from) (struct rq *this_rq, struct task_struct *task,
1012 int running);
1013 void (*switched_to) (struct rq *this_rq, struct task_struct *task,
1014 int running);
1015 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1016 int oldprio, int running);
Peter Zijlstra810b3812008-02-29 15:21:01 -05001017
1018#ifdef CONFIG_FAIR_GROUP_SCHED
1019 void (*moved_group) (struct task_struct *p);
1020#endif
Ingo Molnar20b8a592007-07-09 18:51:58 +02001021};
1022
1023struct load_weight {
1024 unsigned long weight, inv_weight;
1025};
1026
1027/*
1028 * CFS stats for a schedulable entity (task, task-group etc)
1029 *
1030 * Current field usage histogram:
1031 *
1032 * 4 se->block_start
1033 * 4 se->run_node
1034 * 4 se->sleep_start
Ingo Molnar20b8a592007-07-09 18:51:58 +02001035 * 6 se->load.weight
Ingo Molnar20b8a592007-07-09 18:51:58 +02001036 */
1037struct sched_entity {
Ingo Molnar20b8a592007-07-09 18:51:58 +02001038 struct load_weight load; /* for load-balancing */
1039 struct rb_node run_node;
Peter Zijlstra4a55bd52008-04-19 19:45:00 +02001040 struct list_head group_node;
Ingo Molnar20b8a592007-07-09 18:51:58 +02001041 unsigned int on_rq;
1042
Ingo Molnar20b8a592007-07-09 18:51:58 +02001043 u64 exec_start;
Ingo Molnar94c18222007-08-02 17:41:40 +02001044 u64 sum_exec_runtime;
Ingo Molnare9acbff2007-10-15 17:00:04 +02001045 u64 vruntime;
Ingo Molnarf6cf8912007-08-28 12:53:24 +02001046 u64 prev_sum_exec_runtime;
Ingo Molnar94c18222007-08-02 17:41:40 +02001047
Ingo Molnar4ae7d5c2008-03-19 01:42:00 +01001048 u64 last_wakeup;
1049 u64 avg_overlap;
1050
Ingo Molnar34cb6132009-01-16 13:36:06 +01001051 u64 start_runtime;
1052 u64 avg_wakeup;
1053 u64 nr_migrations;
1054
Ingo Molnar94c18222007-08-02 17:41:40 +02001055#ifdef CONFIG_SCHEDSTATS
1056 u64 wait_start;
1057 u64 wait_max;
Arjan van de Ven6d082592008-01-25 21:08:35 +01001058 u64 wait_count;
1059 u64 wait_sum;
Ingo Molnar94c18222007-08-02 17:41:40 +02001060
1061 u64 sleep_start;
Ingo Molnar20b8a592007-07-09 18:51:58 +02001062 u64 sleep_max;
Ingo Molnar94c18222007-08-02 17:41:40 +02001063 s64 sum_sleep_runtime;
1064
1065 u64 block_start;
Ingo Molnar20b8a592007-07-09 18:51:58 +02001066 u64 block_max;
1067 u64 exec_max;
Ingo Molnareba1ed42007-10-15 17:00:02 +02001068 u64 slice_max;
Ingo Molnarcc367732007-10-15 17:00:18 +02001069
Ingo Molnarcc367732007-10-15 17:00:18 +02001070 u64 nr_migrations_cold;
1071 u64 nr_failed_migrations_affine;
1072 u64 nr_failed_migrations_running;
1073 u64 nr_failed_migrations_hot;
1074 u64 nr_forced_migrations;
1075 u64 nr_forced2_migrations;
1076
1077 u64 nr_wakeups;
1078 u64 nr_wakeups_sync;
1079 u64 nr_wakeups_migrate;
1080 u64 nr_wakeups_local;
1081 u64 nr_wakeups_remote;
1082 u64 nr_wakeups_affine;
1083 u64 nr_wakeups_affine_attempts;
1084 u64 nr_wakeups_passive;
1085 u64 nr_wakeups_idle;
Ingo Molnar94c18222007-08-02 17:41:40 +02001086#endif
1087
Ingo Molnar20b8a592007-07-09 18:51:58 +02001088#ifdef CONFIG_FAIR_GROUP_SCHED
1089 struct sched_entity *parent;
1090 /* rq on which this entity is (to be) queued: */
1091 struct cfs_rq *cfs_rq;
1092 /* rq "owned" by this entity/group: */
1093 struct cfs_rq *my_q;
1094#endif
1095};
Ingo Molnar70b97a72006-07-03 00:25:42 -07001096
Peter Zijlstrafa717062008-01-25 21:08:27 +01001097struct sched_rt_entity {
1098 struct list_head run_list;
Peter Zijlstra78f2c7d2008-01-25 21:08:27 +01001099 unsigned long timeout;
Richard Kennedybee367e2008-08-01 13:24:08 +01001100 unsigned int time_slice;
Peter Zijlstra6f505b12008-01-25 21:08:30 +01001101 int nr_cpus_allowed;
1102
Peter Zijlstra58d6c2d2008-04-19 19:45:00 +02001103 struct sched_rt_entity *back;
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01001104#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra6f505b12008-01-25 21:08:30 +01001105 struct sched_rt_entity *parent;
1106 /* rq on which this entity is (to be) queued: */
1107 struct rt_rq *rt_rq;
1108 /* rq "owned" by this entity/group: */
1109 struct rt_rq *my_q;
1110#endif
Peter Zijlstrafa717062008-01-25 21:08:27 +01001111};
1112
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113struct task_struct {
1114 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
Roman Zippelf7e42172007-05-09 02:35:17 -07001115 void *stack;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 atomic_t usage;
William Cohen97dc32c2007-05-08 00:23:41 -07001117 unsigned int flags; /* per process flags, defined below */
1118 unsigned int ptrace;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119
Paolo 'Blaisorblade' Giarrusso36772092005-05-05 16:16:12 -07001120 int lock_depth; /* BKL lock depth */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121
Peter Williams2dd73a42006-06-27 02:54:34 -07001122#ifdef CONFIG_SMP
1123#ifdef __ARCH_WANT_UNLOCKED_CTXSW
Nick Piggin4866cde2005-06-25 14:57:23 -07001124 int oncpu;
1125#endif
Peter Williams2dd73a42006-06-27 02:54:34 -07001126#endif
Ingo Molnar50e645a2007-07-09 18:52:00 +02001127
Ingo Molnarb29739f2006-06-27 02:54:51 -07001128 int prio, static_prio, normal_prio;
Richard Kennedyc7aceab2008-05-15 12:09:15 +01001129 unsigned int rt_priority;
Ingo Molnar5522d5d2007-10-15 17:00:12 +02001130 const struct sched_class *sched_class;
Ingo Molnar20b8a592007-07-09 18:51:58 +02001131 struct sched_entity se;
Peter Zijlstrafa717062008-01-25 21:08:27 +01001132 struct sched_rt_entity rt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133
Avi Kivitye107be32007-07-26 13:40:43 +02001134#ifdef CONFIG_PREEMPT_NOTIFIERS
1135 /* list of struct preempt_notifier: */
1136 struct hlist_head preempt_notifiers;
1137#endif
1138
Alexey Dobriyan18796aa2007-10-16 23:30:26 -07001139 /*
1140 * fpu_counter contains the number of consecutive context switches
1141 * that the FPU is used. If this is over a threshold, the lazy fpu
1142 * saving becomes unlazy to save the trap. This is an unsigned char
1143 * so that after 256 times the counter wraps and the behavior turns
1144 * lazy again; this to deal with bursty apps that only use FPU for
1145 * a short time
1146 */
1147 unsigned char fpu_counter;
1148 s8 oomkilladj; /* OOM kill score adjustment (bit shift). */
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -07001149#ifdef CONFIG_BLK_DEV_IO_TRACE
Jens Axboe2056a782006-03-23 20:00:26 +01001150 unsigned int btrace_seq;
Alexey Dobriyan6c5c9342006-09-29 01:59:40 -07001151#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152
William Cohen97dc32c2007-05-08 00:23:41 -07001153 unsigned int policy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 cpumask_t cpus_allowed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155
Paul E. McKenneye260be62008-01-25 21:08:24 +01001156#ifdef CONFIG_PREEMPT_RCU
1157 int rcu_read_lock_nesting;
1158 int rcu_flipctr_idx;
1159#endif /* #ifdef CONFIG_PREEMPT_RCU */
1160
Chandra Seetharaman52f17b62006-07-14 00:24:38 -07001161#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162 struct sched_info sched_info;
1163#endif
1164
1165 struct list_head tasks;
Gregory Haskins917b6272008-12-29 09:39:53 -05001166 struct plist_node pushable_tasks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
1168 struct mm_struct *mm, *active_mm;
1169
1170/* task state */
1171 struct linux_binfmt *binfmt;
William Cohen97dc32c2007-05-08 00:23:41 -07001172 int exit_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 int exit_code, exit_signal;
1174 int pdeath_signal; /* The signal sent when the parent dies */
1175 /* ??? */
William Cohen97dc32c2007-05-08 00:23:41 -07001176 unsigned int personality;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 unsigned did_exec:1;
Kentaro Takedaf9ce1f12009-02-05 17:18:11 +09001178 unsigned in_execve:1; /* Tell the LSMs that the process is doing an
1179 * execve */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 pid_t pid;
1181 pid_t tgid;
Arjan van de Ven0a425402006-09-26 10:52:38 +02001182
Arjan van de Ven0a425402006-09-26 10:52:38 +02001183 /* Canary value for the -fstack-protector gcc feature */
1184 unsigned long stack_canary;
Ingo Molnare0032082008-02-14 08:48:23 +01001185
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 /*
1187 * pointers to (original) parent process, youngest child, younger sibling,
1188 * older sibling, respectively. (p->father can be replaced with
Roland McGrathf4700212008-03-24 18:36:23 -07001189 * p->real_parent->pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 */
Roland McGrathf4700212008-03-24 18:36:23 -07001191 struct task_struct *real_parent; /* real parent process */
1192 struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 /*
Roland McGrathf4700212008-03-24 18:36:23 -07001194 * children/sibling forms the list of my natural children
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 */
1196 struct list_head children; /* list of my children */
1197 struct list_head sibling; /* linkage in my parent's children list */
1198 struct task_struct *group_leader; /* threadgroup leader */
1199
Roland McGrathf4700212008-03-24 18:36:23 -07001200 /*
1201 * ptraced is the list of tasks this task is using ptrace on.
1202 * This includes both natural children and PTRACE_ATTACH targets.
1203 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1204 */
1205 struct list_head ptraced;
1206 struct list_head ptrace_entry;
1207
Markus Metzgerca0002a2008-11-25 09:01:25 +01001208#ifdef CONFIG_X86_PTRACE_BTS
1209 /*
1210 * This is the tracer handle for the ptrace BTS extension.
1211 * This field actually belongs to the ptracer task.
1212 */
Markus Metzgere2b371f2009-04-03 16:43:35 +02001213 struct bts_context *bts;
Markus Metzgerca0002a2008-11-25 09:01:25 +01001214#endif /* CONFIG_X86_PTRACE_BTS */
1215
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 /* PID/PID hash table linkage. */
Eric W. Biederman92476d72006-03-31 02:31:42 -08001217 struct pid_link pids[PIDTYPE_MAX];
Oleg Nesterov47e65322006-03-28 16:11:25 -08001218 struct list_head thread_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219
1220 struct completion *vfork_done; /* for vfork() */
1221 int __user *set_child_tid; /* CLONE_CHILD_SETTID */
1222 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
1223
Michael Neulingc66f08b2007-10-18 03:06:34 -07001224 cputime_t utime, stime, utimescaled, stimescaled;
Laurent Vivier9ac52312007-10-15 17:00:19 +02001225 cputime_t gtime;
Balbir Singh93018992007-10-30 00:26:32 +01001226 cputime_t prev_utime, prev_stime;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227 unsigned long nvcsw, nivcsw; /* context switch counts */
Tomas Janousek924b42d2007-07-15 23:39:42 -07001228 struct timespec start_time; /* monotonic time */
1229 struct timespec real_start_time; /* boot based time */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1231 unsigned long min_flt, maj_flt;
1232
Frank Mayharf06febc2008-09-12 09:54:39 -07001233 struct task_cputime cputime_expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 struct list_head cpu_timers[3];
1235
1236/* process credentials */
David Howells3b11a1d2008-11-14 10:39:26 +11001237 const struct cred *real_cred; /* objective and real subjective task
1238 * credentials (COW) */
1239 const struct cred *cred; /* effective (overridable) subjective task
1240 * credentials (COW) */
David Howellsd84f4f92008-11-14 10:39:23 +11001241 struct mutex cred_exec_mutex; /* execve vs ptrace cred calculation mutex */
David Howellsb6dff3e2008-11-14 10:39:16 +11001242
Paolo 'Blaisorblade' Giarrusso36772092005-05-05 16:16:12 -07001243 char comm[TASK_COMM_LEN]; /* executable name excluding path
1244 - access with [gs]et_task_comm (which lock
1245 it with task_lock())
1246 - initialized normally by flush_old_exec */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247/* file system info */
1248 int link_count, total_link_count;
Alexey Dobriyan3d5b6fc2006-09-29 01:59:40 -07001249#ifdef CONFIG_SYSVIPC
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250/* ipc stuff */
1251 struct sysv_sem sysvsem;
Alexey Dobriyan3d5b6fc2006-09-29 01:59:40 -07001252#endif
Ingo Molnar82a1fcb2008-01-25 21:08:02 +01001253#ifdef CONFIG_DETECT_SOFTLOCKUP
1254/* hung task detection */
1255 unsigned long last_switch_timestamp;
1256 unsigned long last_switch_count;
1257#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258/* CPU-specific state of this task */
1259 struct thread_struct thread;
1260/* filesystem information */
1261 struct fs_struct *fs;
1262/* open file information */
1263 struct files_struct *files;
Serge E. Hallyn1651e142006-10-02 02:18:08 -07001264/* namespaces */
Serge E. Hallynab516012006-10-02 02:18:06 -07001265 struct nsproxy *nsproxy;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266/* signal handlers */
1267 struct signal_struct *signal;
1268 struct sighand_struct *sighand;
1269
1270 sigset_t blocked, real_blocked;
Roland McGrathf3de2722008-04-30 00:53:09 -07001271 sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 struct sigpending pending;
1273
1274 unsigned long sas_ss_sp;
1275 size_t sas_ss_size;
1276 int (*notifier)(void *priv);
1277 void *notifier_data;
1278 sigset_t *notifier_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 struct audit_context *audit_context;
Al Virobfef93a2008-01-10 04:53:18 -05001280#ifdef CONFIG_AUDITSYSCALL
1281 uid_t loginuid;
Eric Paris4746ec52008-01-08 10:06:53 -05001282 unsigned int sessionid;
Al Virobfef93a2008-01-10 04:53:18 -05001283#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284 seccomp_t seccomp;
1285
1286/* Thread group tracking */
1287 u32 parent_exec_id;
1288 u32 self_exec_id;
1289/* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
1290 spinlock_t alloc_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291
Ingo Molnarb29739f2006-06-27 02:54:51 -07001292 /* Protection of the PI data structures: */
1293 spinlock_t pi_lock;
1294
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001295#ifdef CONFIG_RT_MUTEXES
1296 /* PI waiters blocked on a rt_mutex held by this task */
1297 struct plist_head pi_waiters;
1298 /* Deadlock detection and priority inheritance handling */
1299 struct rt_mutex_waiter *pi_blocked_on;
Ingo Molnar23f78d4a2006-06-27 02:54:53 -07001300#endif
1301
Ingo Molnar408894e2006-01-09 15:59:20 -08001302#ifdef CONFIG_DEBUG_MUTEXES
1303 /* mutex deadlock detection */
1304 struct mutex_waiter *blocked_on;
1305#endif
Ingo Molnarde30a2b2006-07-03 00:24:42 -07001306#ifdef CONFIG_TRACE_IRQFLAGS
1307 unsigned int irq_events;
1308 int hardirqs_enabled;
1309 unsigned long hardirq_enable_ip;
1310 unsigned int hardirq_enable_event;
1311 unsigned long hardirq_disable_ip;
1312 unsigned int hardirq_disable_event;
1313 int softirqs_enabled;
1314 unsigned long softirq_disable_ip;
1315 unsigned int softirq_disable_event;
1316 unsigned long softirq_enable_ip;
1317 unsigned int softirq_enable_event;
1318 int hardirq_context;
1319 int softirq_context;
1320#endif
Ingo Molnarfbb9ce952006-07-03 00:24:50 -07001321#ifdef CONFIG_LOCKDEP
Peter Zijlstrabdb94412008-02-25 23:02:48 +01001322# define MAX_LOCK_DEPTH 48UL
Ingo Molnarfbb9ce952006-07-03 00:24:50 -07001323 u64 curr_chain_key;
1324 int lockdep_depth;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -07001325 unsigned int lockdep_recursion;
Richard Kennedyc7aceab2008-05-15 12:09:15 +01001326 struct held_lock held_locks[MAX_LOCK_DEPTH];
Nick Piggincf40bd12009-01-21 08:12:39 +01001327 gfp_t lockdep_reclaim_gfp;
Ingo Molnarfbb9ce952006-07-03 00:24:50 -07001328#endif
Ingo Molnar408894e2006-01-09 15:59:20 -08001329
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330/* journalling filesystem info */
1331 void *journal_info;
1332
Neil Brownd89d8792007-05-01 09:53:42 +02001333/* stacked block device info */
1334 struct bio *bio_list, **bio_tail;
1335
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336/* VM state */
1337 struct reclaim_state *reclaim_state;
1338
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 struct backing_dev_info *backing_dev_info;
1340
1341 struct io_context *io_context;
1342
1343 unsigned long ptrace_message;
1344 siginfo_t *last_siginfo; /* For ptrace use. */
Andrea Righi940389b2008-07-28 00:48:12 +02001345 struct task_io_accounting ioac;
Jay Lan8f0ab512006-09-30 23:28:59 -07001346#if defined(CONFIG_TASK_XACCT)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 u64 acct_rss_mem1; /* accumulated rss usage */
1348 u64 acct_vm_mem1; /* accumulated virtual memory usage */
Jonathan Lim49b5cf32008-07-25 01:48:40 -07001349 cputime_t acct_timexpd; /* stime + utime since last update */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351#ifdef CONFIG_CPUSETS
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 nodemask_t mems_allowed;
1353 int cpuset_mems_generation;
Paul Jackson825a46a2006-03-24 03:16:03 -08001354 int cpuset_mem_spread_rotor;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -07001356#ifdef CONFIG_CGROUPS
Paul Menage817929e2007-10-18 23:39:36 -07001357 /* Control Group info protected by css_set_lock */
1358 struct css_set *cgroups;
1359 /* cg_list protected by css_set_lock and tsk->alloc_lock */
1360 struct list_head cg_list;
Paul Menageddbcc7e2007-10-18 23:39:30 -07001361#endif
Alexey Dobriyan42b2dd02007-10-16 23:27:30 -07001362#ifdef CONFIG_FUTEX
Ingo Molnar0771dfe2006-03-27 01:16:22 -08001363 struct robust_list_head __user *robust_list;
Ingo Molnar34f192c2006-03-27 01:16:24 -08001364#ifdef CONFIG_COMPAT
1365 struct compat_robust_list_head __user *compat_robust_list;
1366#endif
Ingo Molnarc87e2832006-06-27 02:54:58 -07001367 struct list_head pi_state_list;
1368 struct futex_pi_state *pi_state_cache;
Alexey Dobriyan42b2dd02007-10-16 23:27:30 -07001369#endif
Richard Kennedyc7aceab2008-05-15 12:09:15 +01001370#ifdef CONFIG_NUMA
1371 struct mempolicy *mempolicy;
1372 short il_next;
1373#endif
Jens Axboe22e2c502005-06-27 10:55:12 +02001374 atomic_t fs_excl; /* holding fs exclusive resources */
Ingo Molnare56d0902006-01-08 01:01:37 -08001375 struct rcu_head rcu;
Jens Axboeb92ce552006-04-11 13:52:07 +02001376
1377 /*
1378 * cache last used pipe for splice
1379 */
1380 struct pipe_inode_info *splice_pipe;
Shailabh Nagarca74e922006-07-14 00:24:36 -07001381#ifdef CONFIG_TASK_DELAY_ACCT
1382 struct task_delay_info *delays;
1383#endif
Akinobu Mitaf4f154f2006-12-08 02:39:47 -08001384#ifdef CONFIG_FAULT_INJECTION
1385 int make_it_fail;
1386#endif
Peter Zijlstra3e26c142007-10-16 23:25:50 -07001387 struct prop_local_single dirties;
Arjan van de Ven97455122008-01-25 21:08:34 +01001388#ifdef CONFIG_LATENCYTOP
1389 int latency_record_count;
1390 struct latency_record latency_record[LT_SAVECOUNT];
1391#endif
Arjan van de Ven69766752008-09-01 15:52:40 -07001392 /*
1393 * time slack values; these are used to round up poll() and
1394 * select() etc timeout values. These are in nanoseconds.
1395 */
1396 unsigned long timer_slack_ns;
1397 unsigned long default_timer_slack_ns;
David Millerf8d570a2008-11-06 00:37:40 -08001398
1399 struct list_head *scm_work_list;
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01001400#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01001401 /* Index of current stored adress in ret_stack */
1402 int curr_ret_stack;
1403 /* Stack of return addresses for return function tracing */
1404 struct ftrace_ret_stack *ret_stack;
Steven Rostedt8aef2d22009-03-24 01:10:15 -04001405 /* time stamp for last schedule */
1406 unsigned long long ftrace_timestamp;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01001407 /*
1408 * Number of functions that haven't been traced
1409 * because of depth overrun.
1410 */
1411 atomic_t trace_overrun;
Frederic Weisbecker380c4b12008-12-06 03:43:41 +01001412 /* Pause for the tracing */
1413 atomic_t tracing_graph_pause;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01001414#endif
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05001415#ifdef CONFIG_TRACING
1416 /* state flags for use by tracers */
1417 unsigned long trace;
1418#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419};
1420
Rusty Russell76e6eee2009-03-12 14:35:43 -06001421/* Future-safe accessor for struct task_struct's cpus_allowed. */
1422#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed)
1423
Ingo Molnare05606d2007-07-09 18:51:59 +02001424/*
1425 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1426 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1427 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1428 * values are inverted: lower p->prio value means higher priority.
1429 *
1430 * The MAX_USER_RT_PRIO value allows the actual maximum
1431 * RT priority to be separate from the value exported to
1432 * user-space. This allows kernel threads to set their
1433 * priority to a value higher than any user task. Note:
1434 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1435 */
1436
1437#define MAX_USER_RT_PRIO 100
1438#define MAX_RT_PRIO MAX_USER_RT_PRIO
1439
1440#define MAX_PRIO (MAX_RT_PRIO + 40)
1441#define DEFAULT_PRIO (MAX_RT_PRIO + 20)
1442
1443static inline int rt_prio(int prio)
1444{
1445 if (unlikely(prio < MAX_RT_PRIO))
1446 return 1;
1447 return 0;
1448}
1449
Alexey Dobriyane8681712007-10-26 12:17:22 +04001450static inline int rt_task(struct task_struct *p)
Ingo Molnare05606d2007-07-09 18:51:59 +02001451{
1452 return rt_prio(p->prio);
1453}
1454
Alexey Dobriyane8681712007-10-26 12:17:22 +04001455static inline struct pid *task_pid(struct task_struct *task)
Eric W. Biederman22c935f2006-10-02 02:17:09 -07001456{
1457 return task->pids[PIDTYPE_PID].pid;
1458}
1459
Alexey Dobriyane8681712007-10-26 12:17:22 +04001460static inline struct pid *task_tgid(struct task_struct *task)
Eric W. Biederman22c935f2006-10-02 02:17:09 -07001461{
1462 return task->group_leader->pids[PIDTYPE_PID].pid;
1463}
1464
Oleg Nesterov6dda81f2009-04-02 16:58:35 -07001465/*
1466 * Without tasklist or rcu lock it is not safe to dereference
1467 * the result of task_pgrp/task_session even if task == current,
1468 * we can race with another thread doing sys_setsid/sys_setpgid.
1469 */
Alexey Dobriyane8681712007-10-26 12:17:22 +04001470static inline struct pid *task_pgrp(struct task_struct *task)
Eric W. Biederman22c935f2006-10-02 02:17:09 -07001471{
1472 return task->group_leader->pids[PIDTYPE_PGID].pid;
1473}
1474
Alexey Dobriyane8681712007-10-26 12:17:22 +04001475static inline struct pid *task_session(struct task_struct *task)
Eric W. Biederman22c935f2006-10-02 02:17:09 -07001476{
1477 return task->group_leader->pids[PIDTYPE_SID].pid;
1478}
1479
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001480struct pid_namespace;
1481
1482/*
1483 * the helpers to get the task's different pids as they are seen
1484 * from various namespaces
1485 *
1486 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
Eric W. Biederman44c4e1b2008-02-08 04:19:15 -08001487 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1488 * current.
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001489 * task_xid_nr_ns() : id seen from the ns specified;
1490 *
1491 * set_task_vxid() : assigns a virtual id to a task;
1492 *
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001493 * see also pid_nr() etc in include/linux/pid.h
1494 */
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001495pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1496 struct pid_namespace *ns);
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001497
Alexey Dobriyane8681712007-10-26 12:17:22 +04001498static inline pid_t task_pid_nr(struct task_struct *tsk)
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001499{
1500 return tsk->pid;
1501}
1502
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001503static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1504 struct pid_namespace *ns)
1505{
1506 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1507}
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001508
1509static inline pid_t task_pid_vnr(struct task_struct *tsk)
1510{
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001511 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001512}
1513
1514
Alexey Dobriyane8681712007-10-26 12:17:22 +04001515static inline pid_t task_tgid_nr(struct task_struct *tsk)
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001516{
1517 return tsk->tgid;
1518}
1519
Pavel Emelyanov2f2a3a42007-10-18 23:40:19 -07001520pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001521
1522static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1523{
1524 return pid_vnr(task_tgid(tsk));
1525}
1526
1527
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001528static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1529 struct pid_namespace *ns)
1530{
1531 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1532}
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001533
1534static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1535{
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001536 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001537}
1538
1539
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001540static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1541 struct pid_namespace *ns)
1542{
1543 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1544}
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001545
1546static inline pid_t task_session_vnr(struct task_struct *tsk)
1547{
Oleg Nesterov52ee2df2009-04-02 16:58:38 -07001548 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
Pavel Emelyanov7af57292007-10-18 23:40:06 -07001549}
1550
Oleg Nesterov1b0f7ff2009-04-02 16:58:39 -07001551/* obsolete, do not use */
1552static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1553{
1554 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1555}
1556
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557/**
1558 * pid_alive - check that a task structure is not stale
1559 * @p: Task structure to be checked.
1560 *
1561 * Test if a process is not yet dead (at most zombie state)
1562 * If pid_alive fails, then pointers within the task structure
1563 * can be stale and must not be dereferenced.
1564 */
Alexey Dobriyane8681712007-10-26 12:17:22 +04001565static inline int pid_alive(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566{
Eric W. Biederman92476d72006-03-31 02:31:42 -08001567 return p->pids[PIDTYPE_PID].pid != NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568}
1569
Sukadev Bhattiproluf400e192006-09-29 02:00:07 -07001570/**
Serge E. Hallynb460cbc2007-10-18 23:39:52 -07001571 * is_global_init - check if a task structure is init
Henne32602592006-10-06 00:44:01 -07001572 * @tsk: Task structure to be checked.
1573 *
1574 * Check if a task structure is the first user space task the kernel created.
Sukadev Bhattiproluf400e192006-09-29 02:00:07 -07001575 */
Alexey Dobriyane8681712007-10-26 12:17:22 +04001576static inline int is_global_init(struct task_struct *tsk)
Pavel Emelyanovb461cc02007-10-18 23:40:09 -07001577{
1578 return tsk->pid == 1;
1579}
Serge E. Hallynb460cbc2007-10-18 23:39:52 -07001580
1581/*
1582 * is_container_init:
1583 * check whether in the task is init in its own pid namespace.
1584 */
Pavel Emelyanovb461cc02007-10-18 23:40:09 -07001585extern int is_container_init(struct task_struct *tsk);
Sukadev Bhattiproluf400e192006-09-29 02:00:07 -07001586
Cedric Le Goater9ec52092006-10-02 02:19:00 -07001587extern struct pid *cad_pid;
1588
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589extern void free_task(struct task_struct *tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
Ingo Molnare56d0902006-01-08 01:01:37 -08001591
Andrew Morton158d9eb2006-03-31 02:31:34 -08001592extern void __put_task_struct(struct task_struct *t);
Ingo Molnare56d0902006-01-08 01:01:37 -08001593
1594static inline void put_task_struct(struct task_struct *t)
1595{
1596 if (atomic_dec_and_test(&t->usage))
Eric W. Biederman8c7904a2006-03-31 02:31:37 -08001597 __put_task_struct(t);
Ingo Molnare56d0902006-01-08 01:01:37 -08001598}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599
Balbir Singh49048622008-09-05 18:12:23 +02001600extern cputime_t task_utime(struct task_struct *p);
1601extern cputime_t task_stime(struct task_struct *p);
1602extern cputime_t task_gtime(struct task_struct *p);
1603
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604/*
1605 * Per process flags
1606 */
1607#define PF_ALIGNWARN 0x00000001 /* Print alignment warning msgs */
1608 /* Not implemented yet, only for 486*/
1609#define PF_STARTING 0x00000002 /* being created */
1610#define PF_EXITING 0x00000004 /* getting shut down */
Alexey Kuznetsov778e9a92007-06-08 13:47:00 -07001611#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
Laurent Vivier94886b82007-10-15 17:00:19 +02001612#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613#define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
1614#define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
1615#define PF_DUMPCORE 0x00000200 /* dumped core */
1616#define PF_SIGNALED 0x00000400 /* killed by a signal */
1617#define PF_MEMALLOC 0x00000800 /* Allocating memory */
1618#define PF_FLUSHER 0x00001000 /* responsible for disk writeback */
1619#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620#define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
1621#define PF_FROZEN 0x00010000 /* frozen for system suspend */
1622#define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
1623#define PF_KSWAPD 0x00040000 /* I am kswapd */
1624#define PF_SWAPOFF 0x00080000 /* I am in swapoff */
1625#define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
Oleg Nesterov246bb0b2008-07-25 01:47:38 -07001626#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
Jens Axboeb31dc662006-06-13 08:26:10 +02001627#define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
1628#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1629#define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
1630#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
David Rientjes9985b0b2008-06-05 12:57:11 -07001631#define PF_THREAD_BOUND 0x04000000 /* Thread bound to specific cpu */
Paul Jacksonc61afb12006-03-24 03:16:08 -08001632#define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
Thomas Gleixner61a87122006-06-27 02:54:56 -07001633#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
Rafael J. Wysockiba96a0c2007-05-23 13:57:25 -07001634#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezeable */
Rafael J. Wysockiebb12db2008-06-11 22:04:29 +02001635#define PF_FREEZER_NOSIG 0x80000000 /* Freezer won't send signals to it */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636
1637/*
1638 * Only the _current_ task can read/write to tsk->flags, but other
1639 * tasks can access tsk->flags in readonly mode for example
1640 * with tsk_used_math (like during threaded core dumping).
1641 * There is however an exception to this rule during ptrace
1642 * or during fork: the ptracer task is allowed to write to the
1643 * child->flags of its traced child (same goes for fork, the parent
1644 * can write to the child->flags), because we're guaranteed the
1645 * child is not running and in turn not changing child->flags
1646 * at the same time the parent does it.
1647 */
1648#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1649#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1650#define clear_used_math() clear_stopped_child_used_math(current)
1651#define set_used_math() set_stopped_child_used_math(current)
1652#define conditional_stopped_child_used_math(condition, child) \
1653 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1654#define conditional_used_math(condition) \
1655 conditional_stopped_child_used_math(condition, current)
1656#define copy_to_stopped_child_used_math(child) \
1657 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1658/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1659#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1660#define used_math() tsk_used_math(current)
1661
1662#ifdef CONFIG_SMP
Mike Traviscd8ba7c2008-03-26 14:23:49 -07001663extern int set_cpus_allowed_ptr(struct task_struct *p,
Rusty Russell96f874e2008-11-25 02:35:14 +10301664 const struct cpumask *new_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665#else
Mike Traviscd8ba7c2008-03-26 14:23:49 -07001666static inline int set_cpus_allowed_ptr(struct task_struct *p,
Rusty Russell96f874e2008-11-25 02:35:14 +10301667 const struct cpumask *new_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001668{
Rusty Russell96f874e2008-11-25 02:35:14 +10301669 if (!cpumask_test_cpu(0, new_mask))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 return -EINVAL;
1671 return 0;
1672}
1673#endif
Mike Traviscd8ba7c2008-03-26 14:23:49 -07001674static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1675{
1676 return set_cpus_allowed_ptr(p, &new_mask);
1677}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678
Ingo Molnarb3425012009-02-26 20:20:29 +01001679/*
1680 * Architectures can set this to 1 if they have specified
1681 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1682 * but then during bootup it turns out that sched_clock()
1683 * is reliable after all:
1684 */
1685#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1686extern int sched_clock_stable;
1687#endif
1688
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689extern unsigned long long sched_clock(void);
Ingo Molnare436d802007-07-19 21:28:35 +02001690
Peter Zijlstrac1955a32008-08-11 08:59:03 +02001691extern void sched_clock_init(void);
1692extern u64 sched_clock_cpu(int cpu);
1693
Peter Zijlstra3e51f332008-05-03 18:29:28 +02001694#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
Peter Zijlstra3e51f332008-05-03 18:29:28 +02001695static inline void sched_clock_tick(void)
1696{
1697}
1698
1699static inline void sched_clock_idle_sleep_event(void)
1700{
1701}
1702
1703static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1704{
1705}
Ingo Molnare4e4e532008-04-14 08:50:02 +02001706#else
Peter Zijlstra3e51f332008-05-03 18:29:28 +02001707extern void sched_clock_tick(void);
1708extern void sched_clock_idle_sleep_event(void);
1709extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1710#endif
1711
Ingo Molnare436d802007-07-19 21:28:35 +02001712/*
1713 * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
1714 * clock constructed from sched_clock():
1715 */
1716extern unsigned long long cpu_clock(int cpu);
1717
Ingo Molnar36c8b582006-07-03 00:25:41 -07001718extern unsigned long long
Ingo Molnar41b86e92007-07-09 18:51:58 +02001719task_sched_runtime(struct task_struct *task);
Frank Mayharf06febc2008-09-12 09:54:39 -07001720extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721
1722/* sched_exec is called by processes performing an exec */
1723#ifdef CONFIG_SMP
1724extern void sched_exec(void);
1725#else
1726#define sched_exec() {}
1727#endif
1728
Ingo Molnar2aa44d02007-08-23 15:18:02 +02001729extern void sched_clock_idle_sleep_event(void);
1730extern void sched_clock_idle_wakeup_event(u64 delta_ns);
Ingo Molnarbb29ab22007-07-09 18:51:59 +02001731
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732#ifdef CONFIG_HOTPLUG_CPU
1733extern void idle_task_exit(void);
1734#else
1735static inline void idle_task_exit(void) {}
1736#endif
1737
1738extern void sched_idle_next(void);
Ingo Molnarb29739f2006-06-27 02:54:51 -07001739
Thomas Gleixner06d83082008-03-22 09:20:24 +01001740#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1741extern void wake_up_idle_cpu(int cpu);
1742#else
1743static inline void wake_up_idle_cpu(int cpu) { }
1744#endif
1745
Peter Zijlstra21805082007-08-25 18:41:53 +02001746extern unsigned int sysctl_sched_latency;
Peter Zijlstrab2be5e92007-11-09 22:39:37 +01001747extern unsigned int sysctl_sched_min_granularity;
Ingo Molnarbf0f6f22007-07-09 18:51:58 +02001748extern unsigned int sysctl_sched_wakeup_granularity;
Jaswinder Singh Rajput47fea2a2008-12-29 23:39:17 +05301749extern unsigned int sysctl_sched_shares_ratelimit;
1750extern unsigned int sysctl_sched_shares_thresh;
1751#ifdef CONFIG_SCHED_DEBUG
Ingo Molnarbf0f6f22007-07-09 18:51:58 +02001752extern unsigned int sysctl_sched_child_runs_first;
1753extern unsigned int sysctl_sched_features;
Ingo Molnarda84d962007-10-15 17:00:18 +02001754extern unsigned int sysctl_sched_migration_cost;
Peter Zijlstrab82d9fd2007-11-09 22:39:39 +01001755extern unsigned int sysctl_sched_nr_migrate;
Peter Zijlstrab2be5e92007-11-09 22:39:37 +01001756
1757int sched_nr_latency_handler(struct ctl_table *table, int write,
1758 struct file *file, void __user *buffer, size_t *length,
1759 loff_t *ppos);
Ingo Molnar2bd8e6d2007-10-15 17:00:02 +02001760#endif
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01001761extern unsigned int sysctl_sched_rt_period;
1762extern int sysctl_sched_rt_runtime;
Ingo Molnar2bd8e6d2007-10-15 17:00:02 +02001763
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02001764int sched_rt_handler(struct ctl_table *table, int write,
1765 struct file *filp, void __user *buffer, size_t *lenp,
1766 loff_t *ppos);
1767
Ingo Molnar2bd8e6d2007-10-15 17:00:02 +02001768extern unsigned int sysctl_sched_compat_yield;
Ingo Molnarbf0f6f22007-07-09 18:51:58 +02001769
Ingo Molnarb29739f2006-06-27 02:54:51 -07001770#ifdef CONFIG_RT_MUTEXES
Ingo Molnar36c8b582006-07-03 00:25:41 -07001771extern int rt_mutex_getprio(struct task_struct *p);
1772extern void rt_mutex_setprio(struct task_struct *p, int prio);
1773extern void rt_mutex_adjust_pi(struct task_struct *p);
Ingo Molnarb29739f2006-06-27 02:54:51 -07001774#else
Alexey Dobriyane8681712007-10-26 12:17:22 +04001775static inline int rt_mutex_getprio(struct task_struct *p)
Ingo Molnarb29739f2006-06-27 02:54:51 -07001776{
1777 return p->normal_prio;
1778}
Thomas Gleixner95e02ca2006-06-27 02:55:02 -07001779# define rt_mutex_adjust_pi(p) do { } while (0)
Ingo Molnarb29739f2006-06-27 02:54:51 -07001780#endif
1781
Ingo Molnar36c8b582006-07-03 00:25:41 -07001782extern void set_user_nice(struct task_struct *p, long nice);
1783extern int task_prio(const struct task_struct *p);
1784extern int task_nice(const struct task_struct *p);
1785extern int can_nice(const struct task_struct *p, const int nice);
1786extern int task_curr(const struct task_struct *p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787extern int idle_cpu(int cpu);
1788extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
Rusty Russell961ccdd2008-06-23 13:55:38 +10001789extern int sched_setscheduler_nocheck(struct task_struct *, int,
1790 struct sched_param *);
Ingo Molnar36c8b582006-07-03 00:25:41 -07001791extern struct task_struct *idle_task(int cpu);
1792extern struct task_struct *curr_task(int cpu);
1793extern void set_curr_task(int cpu, struct task_struct *p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794
1795void yield(void);
1796
1797/*
1798 * The default (Linux) execution domain.
1799 */
1800extern struct exec_domain default_exec_domain;
1801
1802union thread_union {
1803 struct thread_info thread_info;
1804 unsigned long stack[THREAD_SIZE/sizeof(long)];
1805};
1806
1807#ifndef __HAVE_ARCH_KSTACK_END
1808static inline int kstack_end(void *addr)
1809{
1810 /* Reliable end of stack detection:
1811 * Some APM bios versions misalign the stack
1812 */
1813 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1814}
1815#endif
1816
1817extern union thread_union init_thread_union;
1818extern struct task_struct init_task;
1819
1820extern struct mm_struct init_mm;
1821
Pavel Emelyanov198fe212007-10-18 23:40:06 -07001822extern struct pid_namespace init_pid_ns;
1823
1824/*
1825 * find a task by one of its numerical ids
1826 *
1827 * find_task_by_pid_type_ns():
1828 * it is the most generic call - it finds a task by all id,
1829 * type and namespace specified
1830 * find_task_by_pid_ns():
1831 * finds a task by its pid in the specified namespace
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -07001832 * find_task_by_vpid():
1833 * finds a task by its virtual pid
Pavel Emelyanov198fe212007-10-18 23:40:06 -07001834 *
Pavel Emelyanove49859e2008-07-25 01:48:36 -07001835 * see also find_vpid() etc in include/linux/pid.h
Pavel Emelyanov198fe212007-10-18 23:40:06 -07001836 */
1837
1838extern struct task_struct *find_task_by_pid_type_ns(int type, int pid,
1839 struct pid_namespace *ns);
1840
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -07001841extern struct task_struct *find_task_by_vpid(pid_t nr);
1842extern struct task_struct *find_task_by_pid_ns(pid_t nr,
1843 struct pid_namespace *ns);
Pavel Emelyanov198fe212007-10-18 23:40:06 -07001844
Oleg Nesterov8520d7c2008-02-08 04:19:09 -08001845extern void __set_special_pids(struct pid *pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846
1847/* per-UID process charging. */
Cedric Le Goateracce2922007-07-15 23:40:59 -07001848extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849static inline struct user_struct *get_uid(struct user_struct *u)
1850{
1851 atomic_inc(&u->__count);
1852 return u;
1853}
1854extern void free_uid(struct user_struct *);
Pavel Emelyanov28f300d2007-09-18 22:46:45 -07001855extern void release_uids(struct user_namespace *ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001856
1857#include <asm/current.h>
1858
Atsushi Nemoto3171a032006-09-29 02:00:32 -07001859extern void do_timer(unsigned long ticks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860
Harvey Harrisonb3c97522008-02-13 15:03:15 -08001861extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1862extern int wake_up_process(struct task_struct *tsk);
1863extern void wake_up_new_task(struct task_struct *tsk,
1864 unsigned long clone_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001865#ifdef CONFIG_SMP
1866 extern void kick_process(struct task_struct *tsk);
1867#else
1868 static inline void kick_process(struct task_struct *tsk) { }
1869#endif
Ingo Molnarad46c2c2007-07-09 18:52:00 +02001870extern void sched_fork(struct task_struct *p, int clone_flags);
1871extern void sched_dead(struct task_struct *p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873extern void proc_caches_init(void);
1874extern void flush_signals(struct task_struct *);
Oleg Nesterov10ab8252007-05-09 02:34:37 -07001875extern void ignore_signals(struct task_struct *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876extern void flush_signal_handlers(struct task_struct *, int force_default);
1877extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1878
1879static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1880{
1881 unsigned long flags;
1882 int ret;
1883
1884 spin_lock_irqsave(&tsk->sighand->siglock, flags);
1885 ret = dequeue_signal(tsk, mask, info);
1886 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1887
1888 return ret;
1889}
1890
1891extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1892 sigset_t *mask);
1893extern void unblock_all_signals(void);
1894extern void release_task(struct task_struct * p);
1895extern int send_sig_info(int, struct siginfo *, struct task_struct *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896extern int force_sigsegv(int, struct task_struct *);
1897extern int force_sig_info(int, struct siginfo *, struct task_struct *);
Eric W. Biedermanc4b92fc2006-10-02 02:17:10 -07001898extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
Eric W. Biedermanc4b92fc2006-10-02 02:17:10 -07001899extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
Eric W. Biederman2425c082006-10-02 02:17:28 -07001900extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
Eric W. Biedermanc4b92fc2006-10-02 02:17:10 -07001901extern int kill_pgrp(struct pid *pid, int sig, int priv);
1902extern int kill_pid(struct pid *pid, int sig, int priv);
Matthew Wilcoxc3de4b32007-02-09 08:11:47 -07001903extern int kill_proc_info(int, struct siginfo *, pid_t);
Roland McGrath2b2a1ff2008-07-25 19:45:54 -07001904extern int do_notify_parent(struct task_struct *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905extern void force_sig(int, struct task_struct *);
1906extern void force_sig_specific(int, struct task_struct *);
1907extern int send_sig(int, struct task_struct *, int);
1908extern void zap_other_threads(struct task_struct *p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001909extern struct sigqueue *sigqueue_alloc(void);
1910extern void sigqueue_free(struct sigqueue *);
Oleg Nesterovac5c2152008-04-30 00:52:57 -07001911extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group);
Oleg Nesterov9ac95f22006-02-09 22:41:50 +03001912extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1914
Cedric Le Goater9ec52092006-10-02 02:19:00 -07001915static inline int kill_cad_pid(int sig, int priv)
1916{
1917 return kill_pid(cad_pid, sig, priv);
1918}
1919
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920/* These can be the second arg to send_sig_info/send_group_sig_info. */
1921#define SEND_SIG_NOINFO ((struct siginfo *) 0)
1922#define SEND_SIG_PRIV ((struct siginfo *) 1)
1923#define SEND_SIG_FORCED ((struct siginfo *) 2)
1924
Oleg Nesterov621d3122005-10-30 15:03:45 -08001925static inline int is_si_special(const struct siginfo *info)
1926{
1927 return info <= SEND_SIG_FORCED;
1928}
1929
Linus Torvalds1da177e2005-04-16 15:20:36 -07001930/* True if we are on the alternate signal stack. */
1931
1932static inline int on_sig_stack(unsigned long sp)
1933{
1934 return (sp - current->sas_ss_sp < current->sas_ss_size);
1935}
1936
1937static inline int sas_ss_flags(unsigned long sp)
1938{
1939 return (current->sas_ss_size == 0 ? SS_DISABLE
1940 : on_sig_stack(sp) ? SS_ONSTACK : 0);
1941}
1942
Linus Torvalds1da177e2005-04-16 15:20:36 -07001943/*
1944 * Routines for handling mm_structs
1945 */
1946extern struct mm_struct * mm_alloc(void);
1947
1948/* mmdrop drops the mm and the page tables */
Harvey Harrisonb3c97522008-02-13 15:03:15 -08001949extern void __mmdrop(struct mm_struct *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950static inline void mmdrop(struct mm_struct * mm)
1951{
Ingo Molnar6fb43d72007-07-09 18:52:01 +02001952 if (unlikely(atomic_dec_and_test(&mm->mm_count)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001953 __mmdrop(mm);
1954}
1955
1956/* mmput gets rid of the mappings and all user-space */
1957extern void mmput(struct mm_struct *);
1958/* Grab a reference to a task's mm, if it is not already going away */
1959extern struct mm_struct *get_task_mm(struct task_struct *task);
1960/* Remove the current tasks stale references to the old mm_struct */
1961extern void mm_release(struct task_struct *, struct mm_struct *);
Carsten Otte402b0862008-03-25 18:47:10 +01001962/* Allocate a new mm structure and copy contents from tsk->mm */
1963extern struct mm_struct *dup_mm(struct task_struct *tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964
Alexey Dobriyan6f2c55b2009-04-02 16:56:59 -07001965extern int copy_thread(unsigned long, unsigned long, unsigned long,
1966 struct task_struct *, struct pt_regs *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001967extern void flush_thread(void);
1968extern void exit_thread(void);
1969
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970extern void exit_files(struct task_struct *);
Oleg Nesterov6b3934e2006-03-28 16:11:16 -08001971extern void __cleanup_signal(struct signal_struct *);
Oleg Nesterova7e53282006-03-28 16:11:27 -08001972extern void __cleanup_sighand(struct sighand_struct *);
Oleg Nesterovcbaffba2008-05-26 20:55:42 +04001973
Linus Torvalds1da177e2005-04-16 15:20:36 -07001974extern void exit_itimers(struct signal_struct *);
Oleg Nesterovcbaffba2008-05-26 20:55:42 +04001975extern void flush_itimer_signals(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976
1977extern NORET_TYPE void do_group_exit(int);
1978
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979extern void daemonize(const char *, ...);
1980extern int allow_signal(int);
1981extern int disallow_signal(int);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982
1983extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1984extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
Ingo Molnar36c8b582006-07-03 00:25:41 -07001985struct task_struct *fork_idle(int);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986
1987extern void set_task_comm(struct task_struct *tsk, char *from);
Andrew Morton59714d62008-02-04 22:27:21 -08001988extern char *get_task_comm(char *to, struct task_struct *tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989
1990#ifdef CONFIG_SMP
Markus Metzgera26b89f2009-04-03 16:43:34 +02001991extern void wait_task_context_switch(struct task_struct *p);
Roland McGrath85ba2d82008-07-25 19:45:58 -07001992extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001993#else
Markus Metzgera26b89f2009-04-03 16:43:34 +02001994static inline void wait_task_context_switch(struct task_struct *p) {}
Roland McGrath85ba2d82008-07-25 19:45:58 -07001995static inline unsigned long wait_task_inactive(struct task_struct *p,
1996 long match_state)
1997{
1998 return 1;
1999}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002000#endif
2001
Eric W. Biederman5e85d4a2006-04-18 22:20:16 -07002002#define next_task(p) list_entry(rcu_dereference((p)->tasks.next), struct task_struct, tasks)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002003
2004#define for_each_process(p) \
2005 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2006
David Howellsd84f4f92008-11-14 10:39:23 +11002007extern bool is_single_threaded(struct task_struct *);
2008
Linus Torvalds1da177e2005-04-16 15:20:36 -07002009/*
2010 * Careful: do_each_thread/while_each_thread is a double loop so
2011 * 'break' will not work as expected - use goto instead.
2012 */
2013#define do_each_thread(g, t) \
2014 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2015
2016#define while_each_thread(g, t) \
2017 while ((t = next_thread(t)) != g)
2018
Eric W. Biedermande12a782006-04-10 17:16:49 -06002019/* de_thread depends on thread_group_leader not being a pid based check */
2020#define thread_group_leader(p) (p == p->group_leader)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002021
Eric W. Biederman0804ef42006-10-02 02:17:04 -07002022/* Do to the insanities of de_thread it is possible for a process
2023 * to have the pid of the thread group leader without actually being
2024 * the thread group leader. For iteration through the pids in proc
2025 * all we care about is that we have a task with the appropriate
2026 * pid, we don't actually care if we have the right task.
2027 */
Alexey Dobriyane8681712007-10-26 12:17:22 +04002028static inline int has_group_leader_pid(struct task_struct *p)
Eric W. Biederman0804ef42006-10-02 02:17:04 -07002029{
2030 return p->pid == p->tgid;
2031}
2032
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -07002033static inline
2034int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2035{
2036 return p1->tgid == p2->tgid;
2037}
2038
Ingo Molnar36c8b582006-07-03 00:25:41 -07002039static inline struct task_struct *next_thread(const struct task_struct *p)
Oleg Nesterov47e65322006-03-28 16:11:25 -08002040{
2041 return list_entry(rcu_dereference(p->thread_group.next),
Ingo Molnar36c8b582006-07-03 00:25:41 -07002042 struct task_struct, thread_group);
Oleg Nesterov47e65322006-03-28 16:11:25 -08002043}
2044
Alexey Dobriyane8681712007-10-26 12:17:22 +04002045static inline int thread_group_empty(struct task_struct *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046{
Oleg Nesterov47e65322006-03-28 16:11:25 -08002047 return list_empty(&p->thread_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002048}
2049
2050#define delay_group_leader(p) \
2051 (thread_group_leader(p) && !thread_group_empty(p))
2052
Oleg Nesterov39c626a2009-04-02 16:58:18 -07002053static inline int task_detached(struct task_struct *p)
2054{
2055 return p->exit_signal == -1;
2056}
2057
Linus Torvalds1da177e2005-04-16 15:20:36 -07002058/*
Eric W. Biederman260ea102006-06-23 02:05:18 -07002059 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
Jens Axboe22e2c502005-06-27 10:55:12 +02002060 * subscriptions and synchronises with wait4(). Also used in procfs. Also
Paul Menageddbcc7e2007-10-18 23:39:30 -07002061 * pins the final release of task.io_context. Also protects ->cpuset and
2062 * ->cgroup.subsys[].
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063 *
2064 * Nests both inside and outside of read_lock(&tasklist_lock).
2065 * It must not be nested with write_lock_irq(&tasklist_lock),
2066 * neither inside nor outside.
2067 */
2068static inline void task_lock(struct task_struct *p)
2069{
2070 spin_lock(&p->alloc_lock);
2071}
2072
2073static inline void task_unlock(struct task_struct *p)
2074{
2075 spin_unlock(&p->alloc_lock);
2076}
2077
Oleg Nesterovf63ee722006-03-28 16:11:13 -08002078extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2079 unsigned long *flags);
2080
2081static inline void unlock_task_sighand(struct task_struct *tsk,
2082 unsigned long *flags)
2083{
2084 spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2085}
2086
Al Virof0373602005-11-13 16:06:57 -08002087#ifndef __HAVE_THREAD_FUNCTIONS
2088
Roman Zippelf7e42172007-05-09 02:35:17 -07002089#define task_thread_info(task) ((struct thread_info *)(task)->stack)
2090#define task_stack_page(task) ((task)->stack)
Al Viroa1261f52005-11-13 16:06:55 -08002091
Al Viro10ebffd2005-11-13 16:06:56 -08002092static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2093{
2094 *task_thread_info(p) = *task_thread_info(org);
2095 task_thread_info(p)->task = p;
2096}
2097
2098static inline unsigned long *end_of_stack(struct task_struct *p)
2099{
Roman Zippelf7e42172007-05-09 02:35:17 -07002100 return (unsigned long *)(task_thread_info(p) + 1);
Al Viro10ebffd2005-11-13 16:06:56 -08002101}
2102
Al Virof0373602005-11-13 16:06:57 -08002103#endif
2104
FUJITA Tomonori8b05c7e2008-07-23 21:26:53 -07002105static inline int object_is_on_stack(void *obj)
2106{
2107 void *stack = task_stack_page(current);
2108
2109 return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2110}
2111
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +10002112extern void thread_info_cache_init(void);
2113
Eric Sandeen7c9f8862008-04-22 16:38:23 -05002114#ifdef CONFIG_DEBUG_STACK_USAGE
2115static inline unsigned long stack_not_used(struct task_struct *p)
2116{
2117 unsigned long *n = end_of_stack(p);
2118
2119 do { /* Skip over canary */
2120 n++;
2121 } while (!*n);
2122
2123 return (unsigned long)n - (unsigned long)end_of_stack(p);
2124}
2125#endif
2126
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127/* set thread flags in other task's structures
2128 * - see asm/thread_info.h for TIF_xxxx flags available
2129 */
2130static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2131{
Al Viroa1261f52005-11-13 16:06:55 -08002132 set_ti_thread_flag(task_thread_info(tsk), flag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133}
2134
2135static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2136{
Al Viroa1261f52005-11-13 16:06:55 -08002137 clear_ti_thread_flag(task_thread_info(tsk), flag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138}
2139
2140static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2141{
Al Viroa1261f52005-11-13 16:06:55 -08002142 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002143}
2144
2145static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2146{
Al Viroa1261f52005-11-13 16:06:55 -08002147 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148}
2149
2150static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2151{
Al Viroa1261f52005-11-13 16:06:55 -08002152 return test_ti_thread_flag(task_thread_info(tsk), flag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153}
2154
2155static inline void set_tsk_need_resched(struct task_struct *tsk)
2156{
2157 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2158}
2159
2160static inline void clear_tsk_need_resched(struct task_struct *tsk)
2161{
2162 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2163}
2164
Gregory Haskins8ae121a2008-04-23 07:13:29 -04002165static inline int test_tsk_need_resched(struct task_struct *tsk)
2166{
2167 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2168}
2169
Linus Torvalds1da177e2005-04-16 15:20:36 -07002170static inline int signal_pending(struct task_struct *p)
2171{
2172 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2173}
Matthew Wilcoxf776d122007-12-06 11:15:50 -05002174
Harvey Harrisonb3c97522008-02-13 15:03:15 -08002175extern int __fatal_signal_pending(struct task_struct *p);
Matthew Wilcoxf776d122007-12-06 11:15:50 -05002176
2177static inline int fatal_signal_pending(struct task_struct *p)
2178{
2179 return signal_pending(p) && __fatal_signal_pending(p);
2180}
2181
Oleg Nesterov16882c12008-06-08 21:20:41 +04002182static inline int signal_pending_state(long state, struct task_struct *p)
2183{
2184 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2185 return 0;
2186 if (!signal_pending(p))
2187 return 0;
2188
Oleg Nesterov16882c12008-06-08 21:20:41 +04002189 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2190}
2191
Linus Torvalds1da177e2005-04-16 15:20:36 -07002192static inline int need_resched(void)
2193{
Linus Torvalds9404ef02008-05-12 10:14:22 -07002194 return unlikely(test_thread_flag(TIF_NEED_RESCHED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002195}
2196
2197/*
2198 * cond_resched() and cond_resched_lock(): latency reduction via
2199 * explicit rescheduling in places that are safe. The return
2200 * value indicates whether a reschedule was done in fact.
2201 * cond_resched_lock() will drop the spinlock before scheduling,
2202 * cond_resched_softirq() will enable bhs before scheduling.
2203 */
Linus Torvaldsc3921ab2008-05-11 16:04:48 -07002204extern int _cond_resched(void);
Linus Torvaldsc714a532008-05-12 13:34:13 -07002205#ifdef CONFIG_PREEMPT_BKL
Herbert Xu02b67cc32008-01-25 21:08:28 +01002206static inline int cond_resched(void)
2207{
2208 return 0;
2209}
2210#else
Herbert Xu02b67cc32008-01-25 21:08:28 +01002211static inline int cond_resched(void)
2212{
2213 return _cond_resched();
2214}
2215#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002216extern int cond_resched_lock(spinlock_t * lock);
2217extern int cond_resched_softirq(void);
Linus Torvaldsc3921ab2008-05-11 16:04:48 -07002218static inline int cond_resched_bkl(void)
2219{
2220 return _cond_resched();
2221}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002222
2223/*
2224 * Does a critical section need to be broken due to another
Nick Piggin95c354f2008-01-30 13:31:20 +01002225 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2226 * but a general need for low latency)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002227 */
Nick Piggin95c354f2008-01-30 13:31:20 +01002228static inline int spin_needbreak(spinlock_t *lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002229{
Nick Piggin95c354f2008-01-30 13:31:20 +01002230#ifdef CONFIG_PREEMPT
2231 return spin_is_contended(lock);
2232#else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233 return 0;
Nick Piggin95c354f2008-01-30 13:31:20 +01002234#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002235}
2236
Roland McGrath7bb44ad2007-05-23 13:57:44 -07002237/*
Frank Mayharf06febc2008-09-12 09:54:39 -07002238 * Thread group CPU time accounting.
2239 */
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01002240void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
Peter Zijlstra4da94d492009-02-11 11:30:27 +01002241void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
Frank Mayharf06febc2008-09-12 09:54:39 -07002242
2243static inline void thread_group_cputime_init(struct signal_struct *sig)
2244{
Peter Zijlstra4cd4c1b2009-02-05 12:24:16 +01002245 sig->cputimer.cputime = INIT_CPUTIME;
2246 spin_lock_init(&sig->cputimer.lock);
2247 sig->cputimer.running = 0;
Frank Mayharf06febc2008-09-12 09:54:39 -07002248}
2249
2250static inline void thread_group_cputime_free(struct signal_struct *sig)
2251{
Frank Mayharf06febc2008-09-12 09:54:39 -07002252}
2253
Frank Mayharf06febc2008-09-12 09:54:39 -07002254/*
Roland McGrath7bb44ad2007-05-23 13:57:44 -07002255 * Reevaluate whether the task has signals pending delivery.
2256 * Wake the task if so.
2257 * This is required every time the blocked sigset_t changes.
2258 * callers must hold sighand->siglock.
2259 */
2260extern void recalc_sigpending_and_wake(struct task_struct *t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002261extern void recalc_sigpending(void);
2262
2263extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2264
2265/*
2266 * Wrappers for p->thread_info->cpu access. No-op on UP.
2267 */
2268#ifdef CONFIG_SMP
2269
2270static inline unsigned int task_cpu(const struct task_struct *p)
2271{
Al Viroa1261f52005-11-13 16:06:55 -08002272 return task_thread_info(p)->cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273}
2274
Ingo Molnarc65cc872007-07-09 18:51:58 +02002275extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002276
2277#else
2278
2279static inline unsigned int task_cpu(const struct task_struct *p)
2280{
2281 return 0;
2282}
2283
2284static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2285{
2286}
2287
2288#endif /* CONFIG_SMP */
2289
Linus Torvalds1da177e2005-04-16 15:20:36 -07002290extern void arch_pick_mmap_layout(struct mm_struct *mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002291
Ingo Molnar1a3c3032008-05-12 21:20:52 +02002292#ifdef CONFIG_TRACING
2293extern void
2294__trace_special(void *__tr, void *__data,
2295 unsigned long arg1, unsigned long arg2, unsigned long arg3);
2296#else
2297static inline void
2298__trace_special(void *__tr, void *__data,
2299 unsigned long arg1, unsigned long arg2, unsigned long arg3)
2300{
2301}
2302#endif
2303
Rusty Russell96f874e2008-11-25 02:35:14 +10302304extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2305extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
Siddha, Suresh B5c45bf22006-06-27 02:54:42 -07002306
Linus Torvalds1da177e2005-04-16 15:20:36 -07002307extern void normalize_rt_tasks(void);
2308
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01002309#ifdef CONFIG_GROUP_SCHED
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02002310
Ingo Molnar4cf86d72007-10-15 17:00:14 +02002311extern struct task_group init_task_group;
Peter Zijlstraeff766a2008-04-19 19:45:00 +02002312#ifdef CONFIG_USER_SCHED
2313extern struct task_group root_task_group;
Arun R Bharadwaj6c415b92008-12-01 20:49:05 +05302314extern void set_tg_uid(struct user_struct *user);
Peter Zijlstraeff766a2008-04-19 19:45:00 +02002315#endif
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02002316
Dhaval Gianiec7dc8a2008-04-19 19:44:59 +02002317extern struct task_group *sched_create_group(struct task_group *parent);
Ingo Molnar4cf86d72007-10-15 17:00:14 +02002318extern void sched_destroy_group(struct task_group *tg);
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02002319extern void sched_move_task(struct task_struct *tsk);
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01002320#ifdef CONFIG_FAIR_GROUP_SCHED
Ingo Molnar4cf86d72007-10-15 17:00:14 +02002321extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
Dhaval Giani5cb350b2007-10-15 17:00:14 +02002322extern unsigned long sched_group_shares(struct task_group *tg);
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01002323#endif
2324#ifdef CONFIG_RT_GROUP_SCHED
Peter Zijlstra9f0c1e52008-02-13 15:45:39 +01002325extern int sched_group_set_rt_runtime(struct task_group *tg,
2326 long rt_runtime_us);
2327extern long sched_group_rt_runtime(struct task_group *tg);
Peter Zijlstrad0b27fa2008-04-19 19:44:57 +02002328extern int sched_group_set_rt_period(struct task_group *tg,
2329 long rt_period_us);
2330extern long sched_group_rt_period(struct task_group *tg);
Dhaval Giani54e99122009-02-27 15:13:54 +05302331extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
Peter Zijlstra052f1dc2008-02-13 15:45:40 +01002332#endif
Srivatsa Vaddagiri9b5b7752007-10-15 17:00:09 +02002333#endif
2334
Dhaval Giani54e99122009-02-27 15:13:54 +05302335extern int task_can_switch_user(struct user_struct *up,
2336 struct task_struct *tsk);
2337
Alexey Dobriyan4b98d112007-02-10 01:46:45 -08002338#ifdef CONFIG_TASK_XACCT
2339static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2340{
Andrea Righi940389b2008-07-28 00:48:12 +02002341 tsk->ioac.rchar += amt;
Alexey Dobriyan4b98d112007-02-10 01:46:45 -08002342}
2343
2344static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2345{
Andrea Righi940389b2008-07-28 00:48:12 +02002346 tsk->ioac.wchar += amt;
Alexey Dobriyan4b98d112007-02-10 01:46:45 -08002347}
2348
2349static inline void inc_syscr(struct task_struct *tsk)
2350{
Andrea Righi940389b2008-07-28 00:48:12 +02002351 tsk->ioac.syscr++;
Alexey Dobriyan4b98d112007-02-10 01:46:45 -08002352}
2353
2354static inline void inc_syscw(struct task_struct *tsk)
2355{
Andrea Righi940389b2008-07-28 00:48:12 +02002356 tsk->ioac.syscw++;
Alexey Dobriyan4b98d112007-02-10 01:46:45 -08002357}
2358#else
2359static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2360{
2361}
2362
2363static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2364{
2365}
2366
2367static inline void inc_syscr(struct task_struct *tsk)
2368{
2369}
2370
2371static inline void inc_syscw(struct task_struct *tsk)
2372{
2373}
2374#endif
2375
Dave Hansen82455252008-02-04 22:28:59 -08002376#ifndef TASK_SIZE_OF
2377#define TASK_SIZE_OF(tsk) TASK_SIZE
2378#endif
2379
Balbir Singhcf475ad2008-04-29 01:00:16 -07002380#ifdef CONFIG_MM_OWNER
2381extern void mm_update_next_owner(struct mm_struct *mm);
2382extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2383#else
2384static inline void mm_update_next_owner(struct mm_struct *mm)
2385{
2386}
2387
2388static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2389{
2390}
2391#endif /* CONFIG_MM_OWNER */
2392
Steven Rostedt7c731e02008-05-12 21:20:41 +02002393#define TASK_STATE_TO_CHAR_STR "RSDTtZX"
2394
Linus Torvalds1da177e2005-04-16 15:20:36 -07002395#endif /* __KERNEL__ */
2396
2397#endif