sched.h 84.9 KB
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#ifndef _LINUX_SCHED_H
#define _LINUX_SCHED_H

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#include <uapi/linux/sched.h>
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#include <linux/sched/prio.h>

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struct sched_param {
	int sched_priority;
};

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#include <asm/param.h>	/* for HZ */

#include <linux/capability.h>
#include <linux/threads.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/timex.h>
#include <linux/jiffies.h>
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#include <linux/plist.h>
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#include <linux/rbtree.h>
#include <linux/thread_info.h>
#include <linux/cpumask.h>
#include <linux/errno.h>
#include <linux/nodemask.h>
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#include <linux/mm_types.h>
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#include <linux/preempt_mask.h>
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#include <asm/page.h>
#include <asm/ptrace.h>
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#include <linux/cputime.h>
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#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/signal.h>
#include <linux/compiler.h>
#include <linux/completion.h>
#include <linux/pid.h>
#include <linux/percpu.h>
#include <linux/topology.h>
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#include <linux/proportions.h>
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#include <linux/seccomp.h>
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#include <linux/rcupdate.h>
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#include <linux/rculist.h>
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#include <linux/rtmutex.h>
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#include <linux/time.h>
#include <linux/param.h>
#include <linux/resource.h>
#include <linux/timer.h>
#include <linux/hrtimer.h>
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#include <linux/task_io_accounting.h>
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#include <linux/latencytop.h>
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#include <linux/cred.h>
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#include <linux/llist.h>
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#include <linux/uidgid.h>
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#include <linux/gfp.h>
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#include <asm/processor.h>
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#define SCHED_ATTR_SIZE_VER0	48	/* sizeof first published struct */

/*
 * Extended scheduling parameters data structure.
 *
 * This is needed because the original struct sched_param can not be
 * altered without introducing ABI issues with legacy applications
 * (e.g., in sched_getparam()).
 *
 * However, the possibility of specifying more than just a priority for
 * the tasks may be useful for a wide variety of application fields, e.g.,
 * multimedia, streaming, automation and control, and many others.
 *
 * This variant (sched_attr) is meant at describing a so-called
 * sporadic time-constrained task. In such model a task is specified by:
 *  - the activation period or minimum instance inter-arrival time;
 *  - the maximum (or average, depending on the actual scheduling
 *    discipline) computation time of all instances, a.k.a. runtime;
 *  - the deadline (relative to the actual activation time) of each
 *    instance.
 * Very briefly, a periodic (sporadic) task asks for the execution of
 * some specific computation --which is typically called an instance--
 * (at most) every period. Moreover, each instance typically lasts no more
 * than the runtime and must be completed by time instant t equal to
 * the instance activation time + the deadline.
 *
 * This is reflected by the actual fields of the sched_attr structure:
 *
 *  @size		size of the structure, for fwd/bwd compat.
 *
 *  @sched_policy	task's scheduling policy
 *  @sched_flags	for customizing the scheduler behaviour
 *  @sched_nice		task's nice value      (SCHED_NORMAL/BATCH)
 *  @sched_priority	task's static priority (SCHED_FIFO/RR)
 *  @sched_deadline	representative of the task's deadline
 *  @sched_runtime	representative of the task's runtime
 *  @sched_period	representative of the task's period
 *
 * Given this task model, there are a multiplicity of scheduling algorithms
 * and policies, that can be used to ensure all the tasks will make their
 * timing constraints.
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 *
 * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
 * only user of this new interface. More information about the algorithm
 * available in the scheduling class file or in Documentation/.
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 */
struct sched_attr {
	u32 size;

	u32 sched_policy;
	u64 sched_flags;

	/* SCHED_NORMAL, SCHED_BATCH */
	s32 sched_nice;

	/* SCHED_FIFO, SCHED_RR */
	u32 sched_priority;

	/* SCHED_DEADLINE */
	u64 sched_runtime;
	u64 sched_deadline;
	u64 sched_period;
};

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struct exec_domain;
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struct futex_pi_state;
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struct robust_list_head;
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struct bio_list;
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struct fs_struct;
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struct perf_event_context;
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struct blk_plug;
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struct filename;
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#define VMACACHE_BITS 2
#define VMACACHE_SIZE (1U << VMACACHE_BITS)
#define VMACACHE_MASK (VMACACHE_SIZE - 1)

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/*
 * List of flags we want to share for kernel threads,
 * if only because they are not used by them anyway.
 */
#define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)

/*
 * These are the constant used to fake the fixed-point load-average
 * counting. Some notes:
 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 *    a load-average precision of 10 bits integer + 11 bits fractional
 *  - if you want to count load-averages more often, you need more
 *    precision, or rounding will get you. With 2-second counting freq,
 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 *    11 bit fractions.
 */
extern unsigned long avenrun[];		/* Load averages */
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extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
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#define FSHIFT		11		/* nr of bits of precision */
#define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
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#define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
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#define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
#define EXP_5		2014		/* 1/exp(5sec/5min) */
#define EXP_15		2037		/* 1/exp(5sec/15min) */

#define CALC_LOAD(load,exp,n) \
	load *= exp; \
	load += n*(FIXED_1-exp); \
	load >>= FSHIFT;

extern unsigned long total_forks;
extern int nr_threads;
DECLARE_PER_CPU(unsigned long, process_counts);
extern int nr_processes(void);
extern unsigned long nr_running(void);
extern unsigned long nr_iowait(void);
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extern unsigned long nr_iowait_cpu(int cpu);
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extern unsigned long this_cpu_load(void);


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extern void calc_global_load(unsigned long ticks);
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extern void update_cpu_load_nohz(void);
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extern unsigned long get_parent_ip(unsigned long addr);

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extern void dump_cpu_task(int cpu);

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struct seq_file;
struct cfs_rq;
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struct task_group;
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#ifdef CONFIG_SCHED_DEBUG
extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
extern void proc_sched_set_task(struct task_struct *p);
extern void
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print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
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#endif
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/*
 * Task state bitmask. NOTE! These bits are also
 * encoded in fs/proc/array.c: get_task_state().
 *
 * We have two separate sets of flags: task->state
 * is about runnability, while task->exit_state are
 * about the task exiting. Confusing, but this way
 * modifying one set can't modify the other one by
 * mistake.
 */
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#define TASK_RUNNING		0
#define TASK_INTERRUPTIBLE	1
#define TASK_UNINTERRUPTIBLE	2
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#define __TASK_STOPPED		4
#define __TASK_TRACED		8
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/* in tsk->exit_state */
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#define EXIT_DEAD		16
#define EXIT_ZOMBIE		32
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#define EXIT_TRACE		(EXIT_ZOMBIE | EXIT_DEAD)
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/* in tsk->state again */
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#define TASK_DEAD		64
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#define TASK_WAKEKILL		128
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#define TASK_WAKING		256
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#define TASK_PARKED		512
#define TASK_STATE_MAX		1024
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#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
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extern char ___assert_task_state[1 - 2*!!(
		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
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/* Convenience macros for the sake of set_task_state */
#define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
#define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
#define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
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/* Convenience macros for the sake of wake_up */
#define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
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#define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
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/* get_task_state() */
#define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
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				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
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				 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
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#define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
#define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
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#define task_is_stopped_or_traced(task)	\
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			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
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#define task_contributes_to_load(task)	\
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				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
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				 (task->flags & PF_FROZEN) == 0)
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#define __set_task_state(tsk, state_value)		\
	do { (tsk)->state = (state_value); } while (0)
#define set_task_state(tsk, state_value)		\
	set_mb((tsk)->state, (state_value))

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/*
 * set_current_state() includes a barrier so that the write of current->state
 * is correctly serialised wrt the caller's subsequent test of whether to
 * actually sleep:
 *
 *	set_current_state(TASK_UNINTERRUPTIBLE);
 *	if (do_i_need_to_sleep())
 *		schedule();
 *
 * If the caller does not need such serialisation then use __set_current_state()
 */
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#define __set_current_state(state_value)			\
	do { current->state = (state_value); } while (0)
#define set_current_state(state_value)		\
	set_mb(current->state, (state_value))

/* Task command name length */
#define TASK_COMM_LEN 16

#include <linux/spinlock.h>

/*
 * This serializes "schedule()" and also protects
 * the run-queue from deletions/modifications (but
 * _adding_ to the beginning of the run-queue has
 * a separate lock).
 */
extern rwlock_t tasklist_lock;
extern spinlock_t mmlist_lock;

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struct task_struct;
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#ifdef CONFIG_PROVE_RCU
extern int lockdep_tasklist_lock_is_held(void);
#endif /* #ifdef CONFIG_PROVE_RCU */

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extern void sched_init(void);
extern void sched_init_smp(void);
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extern asmlinkage void schedule_tail(struct task_struct *prev);
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extern void init_idle(struct task_struct *idle, int cpu);
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extern void init_idle_bootup_task(struct task_struct *idle);
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extern int runqueue_is_locked(int cpu);
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#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
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extern void nohz_balance_enter_idle(int cpu);
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extern void set_cpu_sd_state_idle(void);
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extern int get_nohz_timer_target(int pinned);
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#else
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static inline void nohz_balance_enter_idle(int cpu) { }
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static inline void set_cpu_sd_state_idle(void) { }
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static inline int get_nohz_timer_target(int pinned)
{
	return smp_processor_id();
}
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#endif
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/*
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 * Only dump TASK_* tasks. (0 for all tasks)
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 */
extern void show_state_filter(unsigned long state_filter);

static inline void show_state(void)
{
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	show_state_filter(0);
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}

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extern void show_regs(struct pt_regs *);

/*
 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 * task), SP is the stack pointer of the first frame that should be shown in the back
 * trace (or NULL if the entire call-chain of the task should be shown).
 */
extern void show_stack(struct task_struct *task, unsigned long *sp);

void io_schedule(void);
long io_schedule_timeout(long timeout);

extern void cpu_init (void);
extern void trap_init(void);
extern void update_process_times(int user);
extern void scheduler_tick(void);

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extern void sched_show_task(struct task_struct *p);

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#ifdef CONFIG_LOCKUP_DETECTOR
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extern void touch_softlockup_watchdog(void);
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extern void touch_softlockup_watchdog_sync(void);
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extern void touch_all_softlockup_watchdogs(void);
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extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
				  void __user *buffer,
				  size_t *lenp, loff_t *ppos);
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extern unsigned int  softlockup_panic;
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void lockup_detector_init(void);
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#else
static inline void touch_softlockup_watchdog(void)
{
}
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static inline void touch_softlockup_watchdog_sync(void)
{
}
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static inline void touch_all_softlockup_watchdogs(void)
{
}
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static inline void lockup_detector_init(void)
{
}
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#endif

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#ifdef CONFIG_DETECT_HUNG_TASK
void reset_hung_task_detector(void);
#else
static inline void reset_hung_task_detector(void)
{
}
#endif

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/* Attach to any functions which should be ignored in wchan output. */
#define __sched		__attribute__((__section__(".sched.text")))
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/* Linker adds these: start and end of __sched functions */
extern char __sched_text_start[], __sched_text_end[];

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/* Is this address in the __sched functions? */
extern int in_sched_functions(unsigned long addr);

#define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
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extern signed long schedule_timeout(signed long timeout);
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extern signed long schedule_timeout_interruptible(signed long timeout);
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extern signed long schedule_timeout_killable(signed long timeout);
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extern signed long schedule_timeout_uninterruptible(signed long timeout);
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asmlinkage void schedule(void);
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extern void schedule_preempt_disabled(void);
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struct nsproxy;
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struct user_namespace;
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#ifdef CONFIG_MMU
extern void arch_pick_mmap_layout(struct mm_struct *mm);
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extern unsigned long
arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
		       unsigned long, unsigned long);
extern unsigned long
arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
			  unsigned long len, unsigned long pgoff,
			  unsigned long flags);
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#else
static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
#endif
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#define SUID_DUMP_DISABLE	0	/* No setuid dumping */
#define SUID_DUMP_USER		1	/* Dump as user of process */
#define SUID_DUMP_ROOT		2	/* Dump as root */

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/* mm flags */
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/* for SUID_DUMP_* above */
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#define MMF_DUMPABLE_BITS 2
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#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
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extern void set_dumpable(struct mm_struct *mm, int value);
/*
 * This returns the actual value of the suid_dumpable flag. For things
 * that are using this for checking for privilege transitions, it must
 * test against SUID_DUMP_USER rather than treating it as a boolean
 * value.
 */
static inline int __get_dumpable(unsigned long mm_flags)
{
	return mm_flags & MMF_DUMPABLE_MASK;
}

static inline int get_dumpable(struct mm_struct *mm)
{
	return __get_dumpable(mm->flags);
}

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/* coredump filter bits */
#define MMF_DUMP_ANON_PRIVATE	2
#define MMF_DUMP_ANON_SHARED	3
#define MMF_DUMP_MAPPED_PRIVATE	4
#define MMF_DUMP_MAPPED_SHARED	5
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#define MMF_DUMP_ELF_HEADERS	6
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#define MMF_DUMP_HUGETLB_PRIVATE 7
#define MMF_DUMP_HUGETLB_SHARED  8
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#define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
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#define MMF_DUMP_FILTER_BITS	7
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#define MMF_DUMP_FILTER_MASK \
	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
#define MMF_DUMP_FILTER_DEFAULT \
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	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
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	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)

#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
# define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
#else
# define MMF_DUMP_MASK_DEFAULT_ELF	0
#endif
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					/* leave room for more dump flags */
#define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
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#define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
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#define MMF_EXE_FILE_CHANGED	18	/* see prctl_set_mm_exe_file() */
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#define MMF_HAS_UPROBES		19	/* has uprobes */
#define MMF_RECALC_UPROBES	20	/* MMF_HAS_UPROBES can be wrong */
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#define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
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struct sighand_struct {
	atomic_t		count;
	struct k_sigaction	action[_NSIG];
	spinlock_t		siglock;
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	wait_queue_head_t	signalfd_wqh;
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};

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struct pacct_struct {
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	int			ac_flag;
	long			ac_exitcode;
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	unsigned long		ac_mem;
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	cputime_t		ac_utime, ac_stime;
	unsigned long		ac_minflt, ac_majflt;
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};

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struct cpu_itimer {
	cputime_t expires;
	cputime_t incr;
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	u32 error;
	u32 incr_error;
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};

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/**
 * struct cputime - snaphsot of system and user cputime
 * @utime: time spent in user mode
 * @stime: time spent in system mode
 *
 * Gathers a generic snapshot of user and system time.
 */
struct cputime {
	cputime_t utime;
	cputime_t stime;
};

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/**
 * struct task_cputime - collected CPU time counts
 * @utime:		time spent in user mode, in &cputime_t units
 * @stime:		time spent in kernel mode, in &cputime_t units
 * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
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 *
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 * This is an extension of struct cputime that includes the total runtime
 * spent by the task from the scheduler point of view.
 *
 * As a result, this structure groups together three kinds of CPU time
 * that are tracked for threads and thread groups.  Most things considering
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 * CPU time want to group these counts together and treat all three
 * of them in parallel.
 */
struct task_cputime {
	cputime_t utime;
	cputime_t stime;
	unsigned long long sum_exec_runtime;
};
/* Alternate field names when used to cache expirations. */
#define prof_exp	stime
#define virt_exp	utime
#define sched_exp	sum_exec_runtime

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#define INIT_CPUTIME	\
	(struct task_cputime) {					\
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		.utime = 0,					\
		.stime = 0,					\
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		.sum_exec_runtime = 0,				\
	}

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#ifdef CONFIG_PREEMPT_COUNT
#define PREEMPT_DISABLED	(1 + PREEMPT_ENABLED)
#else
#define PREEMPT_DISABLED	PREEMPT_ENABLED
#endif

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/*
 * Disable preemption until the scheduler is running.
 * Reset by start_kernel()->sched_init()->init_idle().
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 *
 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
 * before the scheduler is active -- see should_resched().
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 */
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#define INIT_PREEMPT_COUNT	(PREEMPT_DISABLED + PREEMPT_ACTIVE)
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/**
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 * struct thread_group_cputimer - thread group interval timer counts
 * @cputime:		thread group interval timers.
 * @running:		non-zero when there are timers running and
 * 			@cputime receives updates.
 * @lock:		lock for fields in this struct.
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 *
 * This structure contains the version of task_cputime, above, that is
553
 * used for thread group CPU timer calculations.
554
 */
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struct thread_group_cputimer {
	struct task_cputime cputime;
	int running;
558
	raw_spinlock_t lock;
559 560
};

561
#include <linux/rwsem.h>
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struct autogroup;

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/*
565
 * NOTE! "signal_struct" does not have its own
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 * locking, because a shared signal_struct always
 * implies a shared sighand_struct, so locking
 * sighand_struct is always a proper superset of
 * the locking of signal_struct.
 */
struct signal_struct {
572
	atomic_t		sigcnt;
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	atomic_t		live;
574
	int			nr_threads;
575
	struct list_head	thread_head;
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	wait_queue_head_t	wait_chldexit;	/* for wait4() */

	/* current thread group signal load-balancing target: */
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	struct task_struct	*curr_target;
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	/* shared signal handling: */
	struct sigpending	shared_pending;

	/* thread group exit support */
	int			group_exit_code;
	/* overloaded:
	 * - notify group_exit_task when ->count is equal to notify_count
	 * - everyone except group_exit_task is stopped during signal delivery
	 *   of fatal signals, group_exit_task processes the signal.
	 */
	int			notify_count;
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	struct task_struct	*group_exit_task;
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	/* thread group stop support, overloads group_exit_code too */
	int			group_stop_count;
	unsigned int		flags; /* see SIGNAL_* flags below */

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	/*
	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
	 * manager, to re-parent orphan (double-forking) child processes
	 * to this process instead of 'init'. The service manager is
	 * able to receive SIGCHLD signals and is able to investigate
	 * the process until it calls wait(). All children of this
	 * process will inherit a flag if they should look for a
	 * child_subreaper process at exit.
	 */
	unsigned int		is_child_subreaper:1;
	unsigned int		has_child_subreaper:1;

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	/* POSIX.1b Interval Timers */
612 613
	int			posix_timer_id;
	struct list_head	posix_timers;
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	/* ITIMER_REAL timer for the process */
616
	struct hrtimer real_timer;
617
	struct pid *leader_pid;
618
	ktime_t it_real_incr;
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	/*
	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
	 * values are defined to 0 and 1 respectively
	 */
	struct cpu_itimer it[2];
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627
	/*
628 629
	 * Thread group totals for process CPU timers.
	 * See thread_group_cputimer(), et al, for details.
630
	 */
631
	struct thread_group_cputimer cputimer;
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	/* Earliest-expiration cache. */
	struct task_cputime cputime_expires;

	struct list_head cpu_timers[3];

638
	struct pid *tty_old_pgrp;
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	/* boolean value for session group leader */
	int leader;

	struct tty_struct *tty; /* NULL if no tty */

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#ifdef CONFIG_SCHED_AUTOGROUP
	struct autogroup *autogroup;
#endif
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	/*
	 * Cumulative resource counters for dead threads in the group,
	 * and for reaped dead child processes forked by this group.
	 * Live threads maintain their own counters and add to these
	 * in __exit_signal, except for the group leader.
	 */
654
	cputime_t utime, stime, cutime, cstime;
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	cputime_t gtime;
	cputime_t cgtime;
657
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
658
	struct cputime prev_cputime;
659
#endif
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	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
662
	unsigned long inblock, oublock, cinblock, coublock;
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	unsigned long maxrss, cmaxrss;
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	struct task_io_accounting ioac;
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	/*
	 * Cumulative ns of schedule CPU time fo dead threads in the
	 * group, not including a zombie group leader, (This only differs
	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
	 * other than jiffies.)
	 */
	unsigned long long sum_sched_runtime;

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	/*
	 * We don't bother to synchronize most readers of this at all,
	 * because there is no reader checking a limit that actually needs
	 * to get both rlim_cur and rlim_max atomically, and either one
	 * alone is a single word that can safely be read normally.
	 * getrlimit/setrlimit use task_lock(current->group_leader) to
	 * protect this instead of the siglock, because they really
	 * have no need to disable irqs.
	 */
	struct rlimit rlim[RLIM_NLIMITS];

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#ifdef CONFIG_BSD_PROCESS_ACCT
	struct pacct_struct pacct;	/* per-process accounting information */
#endif
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#ifdef CONFIG_TASKSTATS
	struct taskstats *stats;
#endif
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#ifdef CONFIG_AUDIT
	unsigned audit_tty;
693
	unsigned audit_tty_log_passwd;
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	struct tty_audit_buf *tty_audit_buf;
#endif
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#ifdef CONFIG_CGROUPS
	/*
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	 * group_rwsem prevents new tasks from entering the threadgroup and
	 * member tasks from exiting,a more specifically, setting of
	 * PF_EXITING.  fork and exit paths are protected with this rwsem
	 * using threadgroup_change_begin/end().  Users which require
	 * threadgroup to remain stable should use threadgroup_[un]lock()
	 * which also takes care of exec path.  Currently, cgroup is the
	 * only user.
705
	 */
706
	struct rw_semaphore group_rwsem;
707
#endif
708

709
	oom_flags_t oom_flags;
710 711 712
	short oom_score_adj;		/* OOM kill score adjustment */
	short oom_score_adj_min;	/* OOM kill score adjustment min value.
					 * Only settable by CAP_SYS_RESOURCE. */
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	struct mutex cred_guard_mutex;	/* guard against foreign influences on
					 * credential calculations
					 * (notably. ptrace) */
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};

/*
 * Bits in flags field of signal_struct.
 */
#define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
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#define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
#define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
725
#define SIGNAL_GROUP_COREDUMP	0x00000008 /* coredump in progress */
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/*
 * Pending notifications to parent.
 */
#define SIGNAL_CLD_STOPPED	0x00000010
#define SIGNAL_CLD_CONTINUED	0x00000020
#define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
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#define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */

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/* If true, all threads except ->group_exit_task have pending SIGKILL */
static inline int signal_group_exit(const struct signal_struct *sig)
{
	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
		(sig->group_exit_task != NULL);
}

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/*
 * Some day this will be a full-fledged user tracking system..
 */
struct user_struct {
	atomic_t __count;	/* reference count */
	atomic_t processes;	/* How many processes does this user have? */
	atomic_t files;		/* How many open files does this user have? */
	atomic_t sigpending;	/* How many pending signals does this user have? */
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#ifdef CONFIG_INOTIFY_USER
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	atomic_t inotify_watches; /* How many inotify watches does this user have? */
	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
#endif
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#ifdef CONFIG_FANOTIFY
	atomic_t fanotify_listeners;
#endif
757
#ifdef CONFIG_EPOLL
758
	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
759
#endif
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#ifdef CONFIG_POSIX_MQUEUE
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	/* protected by mq_lock	*/
	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
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#endif
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	unsigned long locked_shm; /* How many pages of mlocked shm ? */

#ifdef CONFIG_KEYS
	struct key *uid_keyring;	/* UID specific keyring */
	struct key *session_keyring;	/* UID's default session keyring */
#endif

	/* Hash table maintenance information */
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	struct hlist_node uidhash_node;
773
	kuid_t uid;
774

775
#ifdef CONFIG_PERF_EVENTS
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	atomic_long_t locked_vm;
#endif
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};

780
extern int uids_sysfs_init(void);
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782
extern struct user_struct *find_user(kuid_t);
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extern struct user_struct root_user;
#define INIT_USER (&root_user)

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struct backing_dev_info;
struct reclaim_state;

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#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
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struct sched_info {
	/* cumulative counters */
794
	unsigned long pcount;	      /* # of times run on this cpu */
795
	unsigned long long run_delay; /* time spent waiting on a runqueue */
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	/* timestamps */
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	unsigned long long last_arrival,/* when we last ran on a cpu */
			   last_queued;	/* when we were last queued to run */
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};
801
#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
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#ifdef CONFIG_TASK_DELAY_ACCT
struct task_delay_info {
	spinlock_t	lock;
	unsigned int	flags;	/* Private per-task flags */

	/* For each stat XXX, add following, aligned appropriately
	 *
	 * struct timespec XXX_start, XXX_end;
	 * u64 XXX_delay;
	 * u32 XXX_count;
	 *
	 * Atomicity of updates to XXX_delay, XXX_count protected by
	 * single lock above (split into XXX_lock if contention is an issue).
	 */
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	/*
	 * XXX_count is incremented on every XXX operation, the delay
	 * associated with the operation is added to XXX_delay.
	 * XXX_delay contains the accumulated delay time in nanoseconds.
	 */
	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
	u64 blkio_delay;	/* wait for sync block io completion */
	u64 swapin_delay;	/* wait for swapin block io completion */
	u32 blkio_count;	/* total count of the number of sync block */
				/* io operations performed */
	u32 swapin_count;	/* total count of the number of swapin block */
				/* io operations performed */
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	struct timespec freepages_start, freepages_end;
	u64 freepages_delay;	/* wait for memory reclaim */
	u32 freepages_count;	/* total count of memory reclaim */
834
};
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#endif	/* CONFIG_TASK_DELAY_ACCT */

static inline int sched_info_on(void)
{
#ifdef CONFIG_SCHEDSTATS
	return 1;
#elif defined(CONFIG_TASK_DELAY_ACCT)
	extern int delayacct_on;
	return delayacct_on;
#else
	return 0;
846
#endif
847
}
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enum cpu_idle_type {
	CPU_IDLE,
	CPU_NOT_IDLE,
	CPU_NEWLY_IDLE,
	CPU_MAX_IDLE_TYPES
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};

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/*
 * Increase resolution of cpu_power calculations
 */
#define SCHED_POWER_SHIFT	10
#define SCHED_POWER_SCALE	(1L << SCHED_POWER_SHIFT)
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/*
 * sched-domains (multiprocessor balancing) declarations:
 */
865
#ifdef CONFIG_SMP
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#define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
#define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
#define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
#define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
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#define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
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#define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
#define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
#define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
#define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
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#define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
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#define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
877
#define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
878
#define SD_NUMA			0x4000	/* cross-node balancing */
879

880 881
extern int __weak arch_sd_sibiling_asym_packing(void);

882 883 884 885 886 887 888 889
struct sched_domain_attr {
	int relax_domain_level;
};

#define SD_ATTR_INIT	(struct sched_domain_attr) {	\
	.relax_domain_level = -1,			\
}

890 891
extern int sched_domain_level_max;

892 893
struct sched_group;

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struct sched_domain {
	/* These fields must be setup */
	struct sched_domain *parent;	/* top domain must be null terminated */
897
	struct sched_domain *child;	/* bottom domain must be null terminated */
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	struct sched_group *groups;	/* the balancing groups of the domain */
	unsigned long min_interval;	/* Minimum balance interval ms */
	unsigned long max_interval;	/* Maximum balance interval ms */
	unsigned int busy_factor;	/* less balancing by factor if busy */
	unsigned int imbalance_pct;	/* No balance until over watermark */
	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
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	unsigned int busy_idx;
	unsigned int idle_idx;
	unsigned int newidle_idx;
	unsigned int wake_idx;
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	unsigned int forkexec_idx;
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	unsigned int smt_gain;
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	int nohz_idle;			/* NOHZ IDLE status */
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	int flags;			/* See SD_* */
913
	int level;
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	/* Runtime fields. */
	unsigned long last_balance;	/* init to jiffies. units in jiffies */
	unsigned int balance_interval;	/* initialise to 1. units in ms. */
	unsigned int nr_balance_failed; /* initialise to 0 */

920
	/* idle_balance() stats */
921
	u64 max_newidle_lb_cost;
922
	unsigned long next_decay_max_lb_cost;
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#ifdef CONFIG_SCHEDSTATS
	/* load_balance() stats */
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	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
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	/* Active load balancing */
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	unsigned int alb_count;
	unsigned int alb_failed;
	unsigned int alb_pushed;
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940
	/* SD_BALANCE_EXEC stats */
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	unsigned int sbe_count;
	unsigned int sbe_balanced;
	unsigned int sbe_pushed;
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	/* SD_BALANCE_FORK stats */
946 947 948
	unsigned int sbf_count;
	unsigned int sbf_balanced;
	unsigned int sbf_pushed;
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	/* try_to_wake_up() stats */
951 952 953
	unsigned int ttwu_wake_remote;
	unsigned int ttwu_move_affine;
	unsigned int ttwu_move_balance;
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#endif
955 956 957
#ifdef CONFIG_SCHED_DEBUG
	char *name;
#endif
958 959 960 961
	union {
		void *private;		/* used during construction */
		struct rcu_head rcu;	/* used during destruction */
	};
962

963
	unsigned int span_weight;
964 965 966 967 968 969 970 971
	/*
	 * Span of all CPUs in this domain.
	 *
	 * NOTE: this field is variable length. (Allocated dynamically
	 * by attaching extra space to the end of the structure,
	 * depending on how many CPUs the kernel has booted up with)
	 */
	unsigned long span[0];
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};

974 975
static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
{
976
	return to_cpumask(sd->span);
977 978
}

979
extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
980
				    struct sched_domain_attr *dattr_new);
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/* Allocate an array of sched domains, for partition_sched_domains(). */
cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);

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bool cpus_share_cache(int this_cpu, int that_cpu);

988
#else /* CONFIG_SMP */
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990
struct sched_domain_attr;
991

992
static inline void
993
partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
994 995
			struct sched_domain_attr *dattr_new)
{
996
}
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static inline bool cpus_share_cache(int this_cpu, int that_cpu)
{
	return true;
}

1003
#endif	/* !CONFIG_SMP */
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struct io_context;			/* See blkdev.h */


1009
#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1010
extern void prefetch_stack(struct task_struct *t);
1011 1012 1013
#else
static inline void prefetch_stack(struct task_struct *t) { }
#endif
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struct audit_context;		/* See audit.c */
struct mempolicy;
1017
struct pipe_inode_info;
1018
struct uts_namespace;
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struct load_weight {
1021 1022
	unsigned long weight;
	u32 inv_weight;
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};

1025 1026 1027
struct sched_avg {
	/*
	 * These sums represent an infinite geometric series and so are bound
1028
	 * above by 1024/(1-y).  Thus we only need a u32 to store them for all
1029 1030 1031 1032
	 * choices of y < 1-2^(-32)*1024.
	 */
	u32 runnable_avg_sum, runnable_avg_period;
	u64 last_runnable_update;
1033
	s64 decay_count;
1034
	unsigned long load_avg_contrib;
1035 1036
};

1037
#ifdef CONFIG_SCHEDSTATS
1038
struct sched_statistics {
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	u64			wait_start;
1040
	u64			wait_max;
1041 1042
	u64			wait_count;
	u64			wait_sum;
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	u64			iowait_count;
	u64			iowait_sum;
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	u64			sleep_start;
	u64			sleep_max;
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	s64			sum_sleep_runtime;

	u64			block_start;
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	u64			block_max;
	u64			exec_max;
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	u64			slice_max;
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	u64			nr_migrations_cold;
	u64			nr_failed_migrations_affine;
	u64			nr_failed_migrations_running;
	u64			nr_failed_migrations_hot;
	u64			nr_forced_migrations;

	u64			nr_wakeups;
	u64			nr_wakeups_sync;
	u64			nr_wakeups_migrate;
	u64			nr_wakeups_local;
	u64			nr_wakeups_remote;
	u64			nr_wakeups_affine;
	u64			nr_wakeups_affine_attempts;
	u64			nr_wakeups_passive;
	u64			nr_wakeups_idle;
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};
#endif

struct sched_entity {
	struct load_weight	load;		/* for load-balancing */
	struct rb_node		run_node;
	struct list_head	group_node;
	unsigned int		on_rq;

	u64			exec_start;
	u64			sum_exec_runtime;
	u64			vruntime;
	u64			prev_sum_exec_runtime;

	u64			nr_migrations;

#ifdef CONFIG_SCHEDSTATS
	struct sched_statistics statistics;
1088 1089
#endif

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#ifdef CONFIG_FAIR_GROUP_SCHED
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	int			depth;
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1092 1093 1094 1095 1096 1097
	struct sched_entity	*parent;
	/* rq on which this entity is (to be) queued: */
	struct cfs_rq		*cfs_rq;
	/* rq "owned" by this entity/group: */
	struct cfs_rq		*my_q;
#endif
1098

1099
#ifdef CONFIG_SMP
1100
	/* Per-entity load-tracking */
1101 1102
	struct sched_avg	avg;
#endif
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1103
};
1104

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1105 1106
struct sched_rt_entity {
	struct list_head run_list;
1107
	unsigned long timeout;
1108
	unsigned long watchdog_stamp;
1109
	unsigned int time_slice;
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1111
	struct sched_rt_entity *back;
1112
#ifdef CONFIG_RT_GROUP_SCHED
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1113 1114 1115 1116 1117 1118
	struct sched_rt_entity	*parent;
	/* rq on which this entity is (to be) queued: */
	struct rt_rq		*rt_rq;
	/* rq "owned" by this entity/group: */
	struct rt_rq		*my_q;
#endif
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1119 1120
};

1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
struct sched_dl_entity {
	struct rb_node	rb_node;

	/*
	 * Original scheduling parameters. Copied here from sched_attr
	 * during sched_setscheduler2(), they will remain the same until
	 * the next sched_setscheduler2().
	 */
	u64 dl_runtime;		/* maximum runtime for each instance	*/
	u64 dl_deadline;	/* relative deadline of each instance	*/
1131
	u64 dl_period;		/* separation of two instances (period) */
1132
	u64 dl_bw;		/* dl_runtime / dl_deadline		*/
1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152

	/*
	 * Actual scheduling parameters. Initialized with the values above,
	 * they are continously updated during task execution. Note that
	 * the remaining runtime could be < 0 in case we are in overrun.
	 */
	s64 runtime;		/* remaining runtime for this instance	*/
	u64 deadline;		/* absolute deadline for this instance	*/
	unsigned int flags;	/* specifying the scheduler behaviour	*/

	/*
	 * Some bool flags:
	 *
	 * @dl_throttled tells if we exhausted the runtime. If so, the
	 * task has to wait for a replenishment to be performed at the
	 * next firing of dl_timer.
	 *
	 * @dl_new tells if a new instance arrived. If so we must
	 * start executing it with full runtime and reset its absolute
	 * deadline;
1153 1154 1155 1156
	 *
	 * @dl_boosted tells if we are boosted due to DI. If so we are
	 * outside bandwidth enforcement mechanism (but only until we
	 * exit the critical section).
1157
	 */
1158
	int dl_throttled, dl_new, dl_boosted;
1159 1160 1161 1162 1163 1164 1165

	/*
	 * Bandwidth enforcement timer. Each -deadline task has its
	 * own bandwidth to be enforced, thus we need one timer per task.
	 */
	struct hrtimer dl_timer;
};
1166

1167 1168
struct rcu_node;

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enum perf_event_task_context {
	perf_invalid_context = -1,
	perf_hw_context = 0,
1172
	perf_sw_context,
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1173 1174 1175
	perf_nr_task_contexts,
};

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struct task_struct {
	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
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1178
	void *stack;
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1179
	atomic_t usage;
1180 1181
	unsigned int flags;	/* per process flags, defined below */
	unsigned int ptrace;
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1182

1183
#ifdef CONFIG_SMP
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1184
	struct llist_node wake_entry;
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1185
	int on_cpu;
1186 1187 1188
	struct task_struct *last_wakee;
	unsigned long wakee_flips;
	unsigned long wakee_flip_decay_ts;
1189 1190

	int wake_cpu;
1191
#endif
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1192
	int on_rq;
1193

1194
	int prio, static_prio, normal_prio;
1195
	unsigned int rt_priority;
1196
	const struct sched_class *sched_class;
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	struct sched_entity se;
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1198
	struct sched_rt_entity rt;
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1199 1200 1201
#ifdef CONFIG_CGROUP_SCHED
	struct task_group *sched_task_group;
#endif
1202
	struct sched_dl_entity dl;
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1204 1205 1206 1207 1208
#ifdef CONFIG_PREEMPT_NOTIFIERS
	/* list of struct preempt_notifier: */
	struct hlist_head preempt_notifiers;
#endif

1209
#ifdef CONFIG_BLK_DEV_IO_TRACE
1210
	unsigned int btrace_seq;
1211
#endif
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1212

1213
	unsigned int policy;
1214
	int nr_cpus_allowed;
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1215 1216
	cpumask_t cpus_allowed;

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1217
#ifdef CONFIG_PREEMPT_RCU
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1218
	int rcu_read_lock_nesting;
1219 1220
	char rcu_read_unlock_special;
	struct list_head rcu_node_entry;
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1221 1222 1223
#endif /* #ifdef CONFIG_PREEMPT_RCU */
#ifdef CONFIG_TREE_PREEMPT_RCU
	struct rcu_node *rcu_blocked_node;
1224
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1225 1226 1227
#ifdef CONFIG_RCU_BOOST
	struct rt_mutex *rcu_boost_mutex;
#endif /* #ifdef CONFIG_RCU_BOOST */
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1228

1229
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
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1230 1231 1232 1233
	struct sched_info sched_info;
#endif

	struct list_head tasks;
1234
#ifdef CONFIG_SMP
1235
	struct plist_node pushable_tasks;
1236
	struct rb_node pushable_dl_tasks;
1237
#endif
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1238 1239

	struct mm_struct *mm, *active_mm;
1240 1241 1242
#ifdef CONFIG_COMPAT_BRK
	unsigned brk_randomized:1;
#endif
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1243 1244 1245
	/* per-thread vma caching */
	u32 vmacache_seqnum;
	struct vm_area_struct *vmacache[VMACACHE_SIZE];
1246 1247 1248
#if defined(SPLIT_RSS_COUNTING)
	struct task_rss_stat	rss_stat;
#endif
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1249
/* task state */
1250
	int exit_state;
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1251 1252
	int exit_code, exit_signal;
	int pdeath_signal;  /*  The signal sent when the parent dies  */
1253
	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
1254 1255

	/* Used for emulating ABI behavior of previous Linux versions */
1256
	unsigned int personality;
1257

1258 1259
	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
				 * execve */
1260 1261
	unsigned in_iowait:1;

1262 1263
	/* task may not gain privileges */
	unsigned no_new_privs:1;
1264 1265 1266

	/* Revert to default priority/policy when forking */
	unsigned sched_reset_on_fork:1;
1267
	unsigned sched_contributes_to_load:1;
1268

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1269 1270
	pid_t pid;
	pid_t tgid;
1271

1272
#ifdef CONFIG_CC_STACKPROTECTOR
1273 1274
	/* Canary value for the -fstack-protector gcc feature */
	unsigned long stack_canary;
1275
#endif
1276
	/*
L
Linus Torvalds 已提交
1277
	 * pointers to (original) parent process, youngest child, younger sibling,
1278
	 * older sibling, respectively.  (p->father can be replaced with
R
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1279
	 * p->real_parent->pid)
L
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1280
	 */
1281 1282
	struct task_struct __rcu *real_parent; /* real parent process */
	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
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1283
	/*
R
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1284
	 * children/sibling forms the list of my natural children
L
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1285 1286 1287 1288 1289
	 */
	struct list_head children;	/* list of my children */
	struct list_head sibling;	/* linkage in my parent's children list */
	struct task_struct *group_leader;	/* threadgroup leader */

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1290 1291 1292 1293 1294 1295 1296 1297
	/*
	 * ptraced is the list of tasks this task is using ptrace on.
	 * This includes both natural children and PTRACE_ATTACH targets.
	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
	 */
	struct list_head ptraced;
	struct list_head ptrace_entry;

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1298
	/* PID/PID hash table linkage. */
1299
	struct pid_link pids[PIDTYPE_MAX];
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1300
	struct list_head thread_group;
1301
	struct list_head thread_node;
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1302 1303 1304 1305 1306

	struct completion *vfork_done;		/* for vfork() */
	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */

1307
	cputime_t utime, stime, utimescaled, stimescaled;
1308
	cputime_t gtime;
1309
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1310
	struct cputime prev_cputime;
1311 1312 1313 1314 1315 1316 1317 1318 1319
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
	seqlock_t vtime_seqlock;
	unsigned long long vtime_snap;
	enum {
		VTIME_SLEEPING = 0,
		VTIME_USER,
		VTIME_SYS,
	} vtime_snap_whence;
1320
#endif
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1321
	unsigned long nvcsw, nivcsw; /* context switch counts */
1322 1323
	struct timespec start_time; 		/* monotonic time */
	struct timespec real_start_time;	/* boot based time */
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/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
	unsigned long min_flt, maj_flt;

1327
	struct task_cputime cputime_expires;
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1328 1329 1330
	struct list_head cpu_timers[3];

/* process credentials */
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1331
	const struct cred __rcu *real_cred; /* objective and real subjective task
1332
					 * credentials (COW) */
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1333
	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1334
					 * credentials (COW) */
1335 1336 1337
	char comm[TASK_COMM_LEN]; /* executable name excluding path
				     - access with [gs]et_task_comm (which lock
				       it with task_lock())
1338
				     - initialized normally by setup_new_exec */
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1339 1340
/* file system info */
	int link_count, total_link_count;
1341
#ifdef CONFIG_SYSVIPC
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1342 1343
/* ipc stuff */
	struct sysv_sem sysvsem;
1344
#endif
1345
#ifdef CONFIG_DETECT_HUNG_TASK
1346 1347 1348
/* hung task detection */
	unsigned long last_switch_count;
#endif
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1349 1350 1351 1352 1353 1354
/* CPU-specific state of this task */
	struct thread_struct thread;
/* filesystem information */
	struct fs_struct *fs;
/* open file information */
	struct files_struct *files;
1355
/* namespaces */
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1356
	struct nsproxy *nsproxy;
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1357 1358 1359 1360 1361
/* signal handlers */
	struct signal_struct *signal;
	struct sighand_struct *sighand;

	sigset_t blocked, real_blocked;
1362
	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
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1363 1364 1365 1366 1367 1368 1369
	struct sigpending pending;

	unsigned long sas_ss_sp;
	size_t sas_ss_size;
	int (*notifier)(void *priv);
	void *notifier_data;
	sigset_t *notifier_mask;
1370
	struct callback_head *task_works;
1371

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1372
	struct audit_context *audit_context;
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1373
#ifdef CONFIG_AUDITSYSCALL
1374
	kuid_t loginuid;
1375
	unsigned int sessionid;
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1376
#endif
1377
	struct seccomp seccomp;
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1378 1379 1380 1381

/* Thread group tracking */
   	u32 parent_exec_id;
   	u32 self_exec_id;
1382 1383
/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
 * mempolicy */
L
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1384 1385
	spinlock_t alloc_lock;

1386
	/* Protection of the PI data structures: */
1387
	raw_spinlock_t pi_lock;
1388

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1389 1390
#ifdef CONFIG_RT_MUTEXES
	/* PI waiters blocked on a rt_mutex held by this task */
1391 1392
	struct rb_root pi_waiters;
	struct rb_node *pi_waiters_leftmost;
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1393 1394
	/* Deadlock detection and priority inheritance handling */
	struct rt_mutex_waiter *pi_blocked_on;
1395 1396
	/* Top pi_waiters task */
	struct task_struct *pi_top_task;
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1397 1398
#endif

1399 1400 1401 1402
#ifdef CONFIG_DEBUG_MUTEXES
	/* mutex deadlock detection */
	struct mutex_waiter *blocked_on;
#endif
1403 1404 1405 1406
#ifdef CONFIG_TRACE_IRQFLAGS
	unsigned int irq_events;
	unsigned long hardirq_enable_ip;
	unsigned long hardirq_disable_ip;
1407
	unsigned int hardirq_enable_event;
1408
	unsigned int hardirq_disable_event;
1409 1410
	int hardirqs_enabled;
	int hardirq_context;
1411 1412
	unsigned long softirq_disable_ip;
	unsigned long softirq_enable_ip;
1413
	unsigned int softirq_disable_event;
1414
	unsigned int softirq_enable_event;
1415
	int softirqs_enabled;
1416 1417
	int softirq_context;
#endif
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1418
#ifdef CONFIG_LOCKDEP
1419
# define MAX_LOCK_DEPTH 48UL
I
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1420 1421 1422
	u64 curr_chain_key;
	int lockdep_depth;
	unsigned int lockdep_recursion;
1423
	struct held_lock held_locks[MAX_LOCK_DEPTH];
1424
	gfp_t lockdep_reclaim_gfp;
I
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1425
#endif
1426

L
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1427 1428 1429
/* journalling filesystem info */
	void *journal_info;

1430
/* stacked block device info */
1431
	struct bio_list *bio_list;
1432

1433 1434 1435 1436 1437
#ifdef CONFIG_BLOCK
/* stack plugging */
	struct blk_plug *plug;
#endif

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1438 1439 1440 1441 1442 1443 1444 1445 1446
/* VM state */
	struct reclaim_state *reclaim_state;

	struct backing_dev_info *backing_dev_info;

	struct io_context *io_context;

	unsigned long ptrace_message;
	siginfo_t *last_siginfo; /* For ptrace use.  */
1447
	struct task_io_accounting ioac;
1448
#if defined(CONFIG_TASK_XACCT)
L
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1449 1450
	u64 acct_rss_mem1;	/* accumulated rss usage */
	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1451
	cputime_t acct_timexpd;	/* stime + utime since last update */
L
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1452 1453
#endif
#ifdef CONFIG_CPUSETS
1454
	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1455
	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1456
	int cpuset_mem_spread_rotor;
1457
	int cpuset_slab_spread_rotor;
L
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1458
#endif
1459
#ifdef CONFIG_CGROUPS
1460
	/* Control Group info protected by css_set_lock */
A
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1461
	struct css_set __rcu *cgroups;
1462 1463
	/* cg_list protected by css_set_lock and tsk->alloc_lock */
	struct list_head cg_list;
1464
#endif
1465
#ifdef CONFIG_FUTEX
1466
	struct robust_list_head __user *robust_list;
1467 1468 1469
#ifdef CONFIG_COMPAT
	struct compat_robust_list_head __user *compat_robust_list;
#endif
1470 1471
	struct list_head pi_state_list;
	struct futex_pi_state *pi_state_cache;
1472
#endif
1473
#ifdef CONFIG_PERF_EVENTS
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1474
	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1475 1476
	struct mutex perf_event_mutex;
	struct list_head perf_event_list;
1477
#endif
1478 1479 1480
#ifdef CONFIG_DEBUG_PREEMPT
	unsigned long preempt_disable_ip;
#endif
1481
#ifdef CONFIG_NUMA
1482
	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1483
	short il_next;
1484
	short pref_node_fork;
1485
#endif
1486 1487 1488
#ifdef CONFIG_NUMA_BALANCING
	int numa_scan_seq;
	unsigned int numa_scan_period;
1489
	unsigned int numa_scan_period_max;
1490
	int numa_preferred_nid;
1491
	unsigned long numa_migrate_retry;
1492
	u64 node_stamp;			/* migration stamp  */
1493 1494
	u64 last_task_numa_placement;
	u64 last_sum_exec_runtime;
1495
	struct callback_head numa_work;
1496

1497 1498 1499
	struct list_head numa_entry;
	struct numa_group *numa_group;

1500 1501 1502 1503 1504
	/*
	 * Exponential decaying average of faults on a per-node basis.
	 * Scheduling placement decisions are made based on the these counts.
	 * The values remain static for the duration of a PTE scan
	 */
1505
	unsigned long *numa_faults_memory;
1506
	unsigned long total_numa_faults;
1507 1508 1509

	/*
	 * numa_faults_buffer records faults per node during the current
1510 1511
	 * scan window. When the scan completes, the counts in
	 * numa_faults_memory decay and these values are copied.
1512
	 */
1513
	unsigned long *numa_faults_buffer_memory;
1514

1515 1516 1517 1518 1519 1520 1521
	/*
	 * Track the nodes the process was running on when a NUMA hinting
	 * fault was incurred.
	 */
	unsigned long *numa_faults_cpu;
	unsigned long *numa_faults_buffer_cpu;

1522 1523 1524 1525 1526 1527 1528 1529
	/*
	 * numa_faults_locality tracks if faults recorded during the last
	 * scan window were remote/local. The task scan period is adapted
	 * based on the locality of the faults with different weights
	 * depending on whether they were shared or private faults
	 */
	unsigned long numa_faults_locality[2];

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1530
	unsigned long numa_pages_migrated;
1531 1532
#endif /* CONFIG_NUMA_BALANCING */

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1533
	struct rcu_head rcu;
1534 1535 1536 1537 1538

	/*
	 * cache last used pipe for splice
	 */
	struct pipe_inode_info *splice_pipe;
1539 1540 1541

	struct page_frag task_frag;

1542 1543
#ifdef	CONFIG_TASK_DELAY_ACCT
	struct task_delay_info *delays;
1544 1545 1546
#endif
#ifdef CONFIG_FAULT_INJECTION
	int make_it_fail;
1547
#endif
1548 1549 1550 1551 1552 1553
	/*
	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
	 * balance_dirty_pages() for some dirty throttling pause
	 */
	int nr_dirtied;
	int nr_dirtied_pause;
1554
	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1555

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1556 1557 1558 1559
#ifdef CONFIG_LATENCYTOP
	int latency_record_count;
	struct latency_record latency_record[LT_SAVECOUNT];
#endif
1560 1561 1562 1563 1564 1565
	/*
	 * time slack values; these are used to round up poll() and
	 * select() etc timeout values. These are in nanoseconds.
	 */
	unsigned long timer_slack_ns;
	unsigned long default_timer_slack_ns;
1566

1567
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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1568
	/* Index of current stored address in ret_stack */
1569 1570 1571
	int curr_ret_stack;
	/* Stack of return addresses for return function tracing */
	struct ftrace_ret_stack	*ret_stack;
1572 1573
	/* time stamp for last schedule */
	unsigned long long ftrace_timestamp;
1574 1575 1576 1577 1578
	/*
	 * Number of functions that haven't been traced
	 * because of depth overrun.
	 */
	atomic_t trace_overrun;
1579 1580
	/* Pause for the tracing */
	atomic_t tracing_graph_pause;
1581
#endif
1582 1583 1584
#ifdef CONFIG_TRACING
	/* state flags for use by tracers */
	unsigned long trace;
1585
	/* bitmask and counter of trace recursion */
1586 1587
	unsigned long trace_recursion;
#endif /* CONFIG_TRACING */
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1588
#ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1589 1590 1591
	struct memcg_batch_info {
		int do_batch;	/* incremented when batch uncharge started */
		struct mem_cgroup *memcg; /* target memcg of uncharge */
1592 1593
		unsigned long nr_pages;	/* uncharged usage */
		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1594
	} memcg_batch;
1595
	unsigned int memcg_kmem_skip_account;
1596
	struct memcg_oom_info {
1597 1598 1599
		struct mem_cgroup *memcg;
		gfp_t gfp_mask;
		int order;
1600 1601
		unsigned int may_oom:1;
	} memcg_oom;
1602
#endif
1603 1604 1605
#ifdef CONFIG_UPROBES
	struct uprobe_task *utask;
#endif
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1606 1607 1608 1609
#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
	unsigned int	sequential_io;
	unsigned int	sequential_io_avg;
#endif
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1610 1611
};

1612
/* Future-safe accessor for struct task_struct's cpus_allowed. */
1613
#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1614

1615 1616
#define TNF_MIGRATED	0x01
#define TNF_NO_GROUP	0x02
1617
#define TNF_SHARED	0x04
1618
#define TNF_FAULT_LOCAL	0x08
1619

1620
#ifdef CONFIG_NUMA_BALANCING
1621
extern void task_numa_fault(int last_node, int node, int pages, int flags);
1622
extern pid_t task_numa_group_id(struct task_struct *p);
1623
extern void set_numabalancing_state(bool enabled);
1624
extern void task_numa_free(struct task_struct *p);
1625 1626
extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
					int src_nid, int dst_cpu);
1627
#else
1628
static inline void task_numa_fault(int last_node, int node, int pages,
1629
				   int flags)
1630 1631
{
}
1632 1633 1634 1635
static inline pid_t task_numa_group_id(struct task_struct *p)
{
	return 0;
}
1636 1637 1638
static inline void set_numabalancing_state(bool enabled)
{
}
1639 1640 1641
static inline void task_numa_free(struct task_struct *p)
{
}
1642 1643 1644 1645 1646
static inline bool should_numa_migrate_memory(struct task_struct *p,
				struct page *page, int src_nid, int dst_cpu)
{
	return true;
}
1647 1648
#endif

A
Alexey Dobriyan 已提交
1649
static inline struct pid *task_pid(struct task_struct *task)
1650 1651 1652 1653
{
	return task->pids[PIDTYPE_PID].pid;
}

A
Alexey Dobriyan 已提交
1654
static inline struct pid *task_tgid(struct task_struct *task)
1655 1656 1657 1658
{
	return task->group_leader->pids[PIDTYPE_PID].pid;
}

1659 1660 1661 1662 1663
/*
 * Without tasklist or rcu lock it is not safe to dereference
 * the result of task_pgrp/task_session even if task == current,
 * we can race with another thread doing sys_setsid/sys_setpgid.
 */
A
Alexey Dobriyan 已提交
1664
static inline struct pid *task_pgrp(struct task_struct *task)
1665 1666 1667 1668
{
	return task->group_leader->pids[PIDTYPE_PGID].pid;
}

A
Alexey Dobriyan 已提交
1669
static inline struct pid *task_session(struct task_struct *task)
1670 1671 1672 1673
{
	return task->group_leader->pids[PIDTYPE_SID].pid;
}

1674 1675 1676 1677 1678 1679 1680
struct pid_namespace;

/*
 * the helpers to get the task's different pids as they are seen
 * from various namespaces
 *
 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
E
Eric W. Biederman 已提交
1681 1682
 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
 *                     current.
1683 1684 1685 1686 1687 1688
 * task_xid_nr_ns()  : id seen from the ns specified;
 *
 * set_task_vxid()   : assigns a virtual id to a task;
 *
 * see also pid_nr() etc in include/linux/pid.h
 */
1689 1690
pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
			struct pid_namespace *ns);
1691

A
Alexey Dobriyan 已提交
1692
static inline pid_t task_pid_nr(struct task_struct *tsk)
1693 1694 1695 1696
{
	return tsk->pid;
}

1697 1698 1699 1700 1701
static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
					struct pid_namespace *ns)
{
	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
}
1702 1703 1704

static inline pid_t task_pid_vnr(struct task_struct *tsk)
{
1705
	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1706 1707 1708
}


A
Alexey Dobriyan 已提交
1709
static inline pid_t task_tgid_nr(struct task_struct *tsk)
1710 1711 1712 1713
{
	return tsk->tgid;
}

1714
pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1715 1716 1717 1718 1719 1720 1721

static inline pid_t task_tgid_vnr(struct task_struct *tsk)
{
	return pid_vnr(task_tgid(tsk));
}


1722
static inline int pid_alive(const struct task_struct *p);
1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
{
	pid_t pid = 0;

	rcu_read_lock();
	if (pid_alive(tsk))
		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
	rcu_read_unlock();

	return pid;
}

static inline pid_t task_ppid_nr(const struct task_struct *tsk)
{
	return task_ppid_nr_ns(tsk, &init_pid_ns);
}

1740 1741
static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
					struct pid_namespace *ns)
1742
{
1743
	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1744 1745 1746 1747
}

static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
{
1748
	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1749 1750 1751
}


1752 1753
static inline pid_t task_session_nr_ns(struct task_struct *tsk,
					struct pid_namespace *ns)
1754
{
1755
	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1756 1757 1758 1759
}

static inline pid_t task_session_vnr(struct task_struct *tsk)
{
1760
	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1761 1762
}

1763 1764 1765 1766 1767
/* obsolete, do not use */
static inline pid_t task_pgrp_nr(struct task_struct *tsk)
{
	return task_pgrp_nr_ns(tsk, &init_pid_ns);
}
1768

L
Linus Torvalds 已提交
1769 1770 1771 1772 1773 1774 1775
/**
 * pid_alive - check that a task structure is not stale
 * @p: Task structure to be checked.
 *
 * Test if a process is not yet dead (at most zombie state)
 * If pid_alive fails, then pointers within the task structure
 * can be stale and must not be dereferenced.
1776 1777
 *
 * Return: 1 if the process is alive. 0 otherwise.
L
Linus Torvalds 已提交
1778
 */
1779
static inline int pid_alive(const struct task_struct *p)
L
Linus Torvalds 已提交
1780
{
1781
	return p->pids[PIDTYPE_PID].pid != NULL;
L
Linus Torvalds 已提交
1782 1783
}

1784
/**
1785
 * is_global_init - check if a task structure is init
1786 1787 1788
 * @tsk: Task structure to be checked.
 *
 * Check if a task structure is the first user space task the kernel created.
1789 1790
 *
 * Return: 1 if the task structure is init. 0 otherwise.
1791
 */
A
Alexey Dobriyan 已提交
1792
static inline int is_global_init(struct task_struct *tsk)
1793 1794 1795
{
	return tsk->pid == 1;
}
1796

1797 1798
extern struct pid *cad_pid;

L
Linus Torvalds 已提交
1799 1800
extern void free_task(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
I
Ingo Molnar 已提交
1801

1802
extern void __put_task_struct(struct task_struct *t);
I
Ingo Molnar 已提交
1803 1804 1805 1806

static inline void put_task_struct(struct task_struct *t)
{
	if (atomic_dec_and_test(&t->usage))
1807
		__put_task_struct(t);
I
Ingo Molnar 已提交
1808
}
L
Linus Torvalds 已提交
1809

1810 1811 1812 1813 1814 1815 1816
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void task_cputime(struct task_struct *t,
			 cputime_t *utime, cputime_t *stime);
extern void task_cputime_scaled(struct task_struct *t,
				cputime_t *utimescaled, cputime_t *stimescaled);
extern cputime_t task_gtime(struct task_struct *t);
#else
1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834
static inline void task_cputime(struct task_struct *t,
				cputime_t *utime, cputime_t *stime)
{
	if (utime)
		*utime = t->utime;
	if (stime)
		*stime = t->stime;
}

static inline void task_cputime_scaled(struct task_struct *t,
				       cputime_t *utimescaled,
				       cputime_t *stimescaled)
{
	if (utimescaled)
		*utimescaled = t->utimescaled;
	if (stimescaled)
		*stimescaled = t->stimescaled;
}
1835 1836 1837 1838 1839 1840

static inline cputime_t task_gtime(struct task_struct *t)
{
	return t->gtime;
}
#endif
1841 1842
extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1843

L
Linus Torvalds 已提交
1844 1845 1846 1847
/*
 * Per process flags
 */
#define PF_EXITING	0x00000004	/* getting shut down */
1848
#define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1849
#define PF_VCPU		0x00000010	/* I'm a virtual CPU */
T
Tejun Heo 已提交
1850
#define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
L
Linus Torvalds 已提交
1851
#define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1852
#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
L
Linus Torvalds 已提交
1853 1854 1855 1856
#define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
#define PF_DUMPCORE	0x00000200	/* dumped core */
#define PF_SIGNALED	0x00000400	/* killed by a signal */
#define PF_MEMALLOC	0x00000800	/* Allocating memory */
1857
#define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
L
Linus Torvalds 已提交
1858
#define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1859
#define PF_USED_ASYNC	0x00004000	/* used async_schedule*(), used by module init */
L
Linus Torvalds 已提交
1860 1861 1862 1863
#define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
#define PF_FROZEN	0x00010000	/* frozen for system suspend */
#define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
#define PF_KSWAPD	0x00040000	/* I am kswapd */
1864
#define PF_MEMALLOC_NOIO 0x00080000	/* Allocating memory without IO involved */
L
Linus Torvalds 已提交
1865
#define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1866
#define PF_KTHREAD	0x00200000	/* I am a kernel thread */
J
Jens Axboe 已提交
1867 1868 1869 1870
#define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
#define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
#define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
#define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1871
#define PF_NO_SETAFFINITY 0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
1872
#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1873
#define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1874
#define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1875
#define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
L
Linus Torvalds 已提交
1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901

/*
 * Only the _current_ task can read/write to tsk->flags, but other
 * tasks can access tsk->flags in readonly mode for example
 * with tsk_used_math (like during threaded core dumping).
 * There is however an exception to this rule during ptrace
 * or during fork: the ptracer task is allowed to write to the
 * child->flags of its traced child (same goes for fork, the parent
 * can write to the child->flags), because we're guaranteed the
 * child is not running and in turn not changing child->flags
 * at the same time the parent does it.
 */
#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
#define clear_used_math() clear_stopped_child_used_math(current)
#define set_used_math() set_stopped_child_used_math(current)
#define conditional_stopped_child_used_math(condition, child) \
	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
#define conditional_used_math(condition) \
	conditional_stopped_child_used_math(condition, current)
#define copy_to_stopped_child_used_math(child) \
	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
#define used_math() tsk_used_math(current)

1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921
/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
static inline gfp_t memalloc_noio_flags(gfp_t flags)
{
	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
		flags &= ~__GFP_IO;
	return flags;
}

static inline unsigned int memalloc_noio_save(void)
{
	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
	current->flags |= PF_MEMALLOC_NOIO;
	return flags;
}

static inline void memalloc_noio_restore(unsigned int flags)
{
	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
}

1922
/*
1923
 * task->jobctl flags
1924
 */
1925
#define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
1926

1927 1928 1929
#define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
#define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
#define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
1930
#define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
1931
#define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
1932
#define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
T
Tejun Heo 已提交
1933
#define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
1934 1935 1936 1937

#define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
#define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
#define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
1938
#define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
1939
#define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
1940
#define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
T
Tejun Heo 已提交
1941
#define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
1942

1943
#define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1944
#define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1945

1946 1947
extern bool task_set_jobctl_pending(struct task_struct *task,
				    unsigned int mask);
1948
extern void task_clear_jobctl_trapping(struct task_struct *task);
1949 1950
extern void task_clear_jobctl_pending(struct task_struct *task,
				      unsigned int mask);
1951

P
Paul E. McKenney 已提交
1952
#ifdef CONFIG_PREEMPT_RCU
1953 1954

#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1955
#define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1956 1957 1958 1959 1960

static inline void rcu_copy_process(struct task_struct *p)
{
	p->rcu_read_lock_nesting = 0;
	p->rcu_read_unlock_special = 0;
P
Paul E. McKenney 已提交
1961
#ifdef CONFIG_TREE_PREEMPT_RCU
1962
	p->rcu_blocked_node = NULL;
1963 1964 1965 1966
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
#ifdef CONFIG_RCU_BOOST
	p->rcu_boost_mutex = NULL;
#endif /* #ifdef CONFIG_RCU_BOOST */
1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977
	INIT_LIST_HEAD(&p->rcu_node_entry);
}

#else

static inline void rcu_copy_process(struct task_struct *p)
{
}

#endif

1978 1979 1980 1981 1982 1983 1984
static inline void tsk_restore_flags(struct task_struct *task,
				unsigned long orig_flags, unsigned long flags)
{
	task->flags &= ~flags;
	task->flags |= orig_flags & flags;
}

L
Linus Torvalds 已提交
1985
#ifdef CONFIG_SMP
1986 1987 1988
extern void do_set_cpus_allowed(struct task_struct *p,
			       const struct cpumask *new_mask);

1989
extern int set_cpus_allowed_ptr(struct task_struct *p,
1990
				const struct cpumask *new_mask);
L
Linus Torvalds 已提交
1991
#else
1992 1993 1994 1995
static inline void do_set_cpus_allowed(struct task_struct *p,
				      const struct cpumask *new_mask)
{
}
1996
static inline int set_cpus_allowed_ptr(struct task_struct *p,
1997
				       const struct cpumask *new_mask)
L
Linus Torvalds 已提交
1998
{
1999
	if (!cpumask_test_cpu(0, new_mask))
L
Linus Torvalds 已提交
2000 2001 2002 2003
		return -EINVAL;
	return 0;
}
#endif
2004

2005
#ifdef CONFIG_NO_HZ_COMMON
2006 2007 2008 2009 2010
void calc_load_enter_idle(void);
void calc_load_exit_idle(void);
#else
static inline void calc_load_enter_idle(void) { }
static inline void calc_load_exit_idle(void) { }
2011
#endif /* CONFIG_NO_HZ_COMMON */
2012

2013
#ifndef CONFIG_CPUMASK_OFFSTACK
2014 2015 2016 2017
static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
{
	return set_cpus_allowed_ptr(p, &new_mask);
}
2018
#endif
L
Linus Torvalds 已提交
2019

2020
/*
2021 2022 2023 2024 2025 2026
 * Do not use outside of architecture code which knows its limitations.
 *
 * sched_clock() has no promise of monotonicity or bounded drift between
 * CPUs, use (which you should not) requires disabling IRQs.
 *
 * Please use one of the three interfaces below.
2027
 */
2028
extern unsigned long long notrace sched_clock(void);
2029
/*
2030
 * See the comment in kernel/sched/clock.c
2031 2032 2033 2034 2035
 */
extern u64 cpu_clock(int cpu);
extern u64 local_clock(void);
extern u64 sched_clock_cpu(int cpu);

2036

2037
extern void sched_clock_init(void);
2038

2039
#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051
static inline void sched_clock_tick(void)
{
}

static inline void sched_clock_idle_sleep_event(void)
{
}

static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
{
}
#else
2052 2053 2054 2055 2056 2057
/*
 * Architectures can set this to 1 if they have specified
 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
 * but then during bootup it turns out that sched_clock()
 * is reliable after all:
 */
2058 2059 2060
extern int sched_clock_stable(void);
extern void set_sched_clock_stable(void);
extern void clear_sched_clock_stable(void);
2061

2062 2063 2064 2065 2066
extern void sched_clock_tick(void);
extern void sched_clock_idle_sleep_event(void);
extern void sched_clock_idle_wakeup_event(u64 delta_ns);
#endif

2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
/*
 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
 * The reason for this explicit opt-in is not to have perf penalty with
 * slow sched_clocks.
 */
extern void enable_sched_clock_irqtime(void);
extern void disable_sched_clock_irqtime(void);
#else
static inline void enable_sched_clock_irqtime(void) {}
static inline void disable_sched_clock_irqtime(void) {}
#endif

2080
extern unsigned long long
2081
task_sched_runtime(struct task_struct *task);
L
Linus Torvalds 已提交
2082 2083 2084 2085 2086 2087 2088 2089

/* sched_exec is called by processes performing an exec */
#ifdef CONFIG_SMP
extern void sched_exec(void);
#else
#define sched_exec()   {}
#endif

2090 2091
extern void sched_clock_idle_sleep_event(void);
extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2092

L
Linus Torvalds 已提交
2093 2094 2095 2096 2097 2098
#ifdef CONFIG_HOTPLUG_CPU
extern void idle_task_exit(void);
#else
static inline void idle_task_exit(void) {}
#endif

2099
#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2100
extern void wake_up_nohz_cpu(int cpu);
2101
#else
2102
static inline void wake_up_nohz_cpu(int cpu) { }
2103 2104
#endif

2105 2106
#ifdef CONFIG_NO_HZ_FULL
extern bool sched_can_stop_tick(void);
2107
extern u64 scheduler_tick_max_deferment(void);
2108 2109
#else
static inline bool sched_can_stop_tick(void) { return false; }
2110 2111
#endif

2112 2113 2114 2115 2116 2117 2118
#ifdef CONFIG_SCHED_AUTOGROUP
extern void sched_autogroup_create_attach(struct task_struct *p);
extern void sched_autogroup_detach(struct task_struct *p);
extern void sched_autogroup_fork(struct signal_struct *sig);
extern void sched_autogroup_exit(struct signal_struct *sig);
#ifdef CONFIG_PROC_FS
extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2119
extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2120 2121 2122 2123 2124 2125 2126 2127
#endif
#else
static inline void sched_autogroup_create_attach(struct task_struct *p) { }
static inline void sched_autogroup_detach(struct task_struct *p) { }
static inline void sched_autogroup_fork(struct signal_struct *sig) { }
static inline void sched_autogroup_exit(struct signal_struct *sig) { }
#endif

2128
extern bool yield_to(struct task_struct *p, bool preempt);
2129 2130
extern void set_user_nice(struct task_struct *p, long nice);
extern int task_prio(const struct task_struct *p);
2131 2132 2133 2134 2135 2136 2137 2138 2139 2140
/**
 * task_nice - return the nice value of a given task.
 * @p: the task in question.
 *
 * Return: The nice value [ -20 ... 0 ... 19 ].
 */
static inline int task_nice(const struct task_struct *p)
{
	return PRIO_TO_NICE((p)->static_prio);
}
2141 2142
extern int can_nice(const struct task_struct *p, const int nice);
extern int task_curr(const struct task_struct *p);
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extern int idle_cpu(int cpu);
2144 2145
extern int sched_setscheduler(struct task_struct *, int,
			      const struct sched_param *);
2146
extern int sched_setscheduler_nocheck(struct task_struct *, int,
2147
				      const struct sched_param *);
2148 2149
extern int sched_setattr(struct task_struct *,
			 const struct sched_attr *);
2150
extern struct task_struct *idle_task(int cpu);
2151 2152
/**
 * is_idle_task - is the specified task an idle task?
2153
 * @p: the task in question.
2154 2155
 *
 * Return: 1 if @p is an idle task. 0 otherwise.
2156
 */
2157
static inline bool is_idle_task(const struct task_struct *p)
2158 2159 2160
{
	return p->pid == 0;
}
2161 2162
extern struct task_struct *curr_task(int cpu);
extern void set_curr_task(int cpu, struct task_struct *p);
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void yield(void);

/*
 * The default (Linux) execution domain.
 */
extern struct exec_domain	default_exec_domain;

union thread_union {
	struct thread_info thread_info;
	unsigned long stack[THREAD_SIZE/sizeof(long)];
};

#ifndef __HAVE_ARCH_KSTACK_END
static inline int kstack_end(void *addr)
{
	/* Reliable end of stack detection:
	 * Some APM bios versions misalign the stack
	 */
	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
}
#endif

extern union thread_union init_thread_union;
extern struct task_struct init_task;

extern struct   mm_struct init_mm;

2191 2192 2193 2194 2195 2196 2197
extern struct pid_namespace init_pid_ns;

/*
 * find a task by one of its numerical ids
 *
 * find_task_by_pid_ns():
 *      finds a task by its pid in the specified namespace
2198 2199
 * find_task_by_vpid():
 *      finds a task by its virtual pid
2200
 *
2201
 * see also find_vpid() etc in include/linux/pid.h
2202 2203
 */

2204 2205 2206
extern struct task_struct *find_task_by_vpid(pid_t nr);
extern struct task_struct *find_task_by_pid_ns(pid_t nr,
		struct pid_namespace *ns);
2207

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/* per-UID process charging. */
2209
extern struct user_struct * alloc_uid(kuid_t);
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static inline struct user_struct *get_uid(struct user_struct *u)
{
	atomic_inc(&u->__count);
	return u;
}
extern void free_uid(struct user_struct *);

#include <asm/current.h>

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extern void xtime_update(unsigned long ticks);
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2221 2222
extern int wake_up_state(struct task_struct *tsk, unsigned int state);
extern int wake_up_process(struct task_struct *tsk);
2223
extern void wake_up_new_task(struct task_struct *tsk);
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#ifdef CONFIG_SMP
 extern void kick_process(struct task_struct *tsk);
#else
 static inline void kick_process(struct task_struct *tsk) { }
#endif
2229
extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2230
extern void sched_dead(struct task_struct *p);
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extern void proc_caches_init(void);
extern void flush_signals(struct task_struct *);
2234
extern void __flush_signals(struct task_struct *);
2235
extern void ignore_signals(struct task_struct *);
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extern void flush_signal_handlers(struct task_struct *, int force_default);
extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);

static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&tsk->sighand->siglock, flags);
	ret = dequeue_signal(tsk, mask, info);
	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);

	return ret;
2249
}
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extern void block_all_signals(int (*notifier)(void *priv), void *priv,
			      sigset_t *mask);
extern void unblock_all_signals(void);
extern void release_task(struct task_struct * p);
extern int send_sig_info(int, struct siginfo *, struct task_struct *);
extern int force_sigsegv(int, struct task_struct *);
extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2258 2259
extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2260 2261
extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
				const struct cred *, u32);
2262 2263
extern int kill_pgrp(struct pid *pid, int sig, int priv);
extern int kill_pid(struct pid *pid, int sig, int priv);
2264
extern int kill_proc_info(int, struct siginfo *, pid_t);
2265
extern __must_check bool do_notify_parent(struct task_struct *, int);
2266
extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
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extern void force_sig(int, struct task_struct *);
extern int send_sig(int, struct task_struct *, int);
2269
extern int zap_other_threads(struct task_struct *p);
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extern struct sigqueue *sigqueue_alloc(void);
extern void sigqueue_free(struct sigqueue *);
2272
extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2273
extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
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static inline void restore_saved_sigmask(void)
{
	if (test_and_clear_restore_sigmask())
2278
		__set_current_blocked(&current->saved_sigmask);
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}

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static inline sigset_t *sigmask_to_save(void)
{
	sigset_t *res = &current->blocked;
	if (unlikely(test_restore_sigmask()))
		res = &current->saved_sigmask;
	return res;
}

2289 2290 2291 2292 2293
static inline int kill_cad_pid(int sig, int priv)
{
	return kill_pid(cad_pid, sig, priv);
}

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/* These can be the second arg to send_sig_info/send_group_sig_info.  */
#define SEND_SIG_NOINFO ((struct siginfo *) 0)
#define SEND_SIG_PRIV	((struct siginfo *) 1)
#define SEND_SIG_FORCED	((struct siginfo *) 2)

2299 2300 2301
/*
 * True if we are on the alternate signal stack.
 */
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static inline int on_sig_stack(unsigned long sp)
{
2304 2305 2306 2307 2308 2309 2310
#ifdef CONFIG_STACK_GROWSUP
	return sp >= current->sas_ss_sp &&
		sp - current->sas_ss_sp < current->sas_ss_size;
#else
	return sp > current->sas_ss_sp &&
		sp - current->sas_ss_sp <= current->sas_ss_size;
#endif
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}

static inline int sas_ss_flags(unsigned long sp)
{
	return (current->sas_ss_size == 0 ? SS_DISABLE
		: on_sig_stack(sp) ? SS_ONSTACK : 0);
}

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static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
{
	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
#ifdef CONFIG_STACK_GROWSUP
		return current->sas_ss_sp;
#else
		return current->sas_ss_sp + current->sas_ss_size;
#endif
	return sp;
}

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/*
 * Routines for handling mm_structs
 */
extern struct mm_struct * mm_alloc(void);

/* mmdrop drops the mm and the page tables */
2336
extern void __mmdrop(struct mm_struct *);
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static inline void mmdrop(struct mm_struct * mm)
{
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Ingo Molnar 已提交
2339
	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
L
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		__mmdrop(mm);
}

/* mmput gets rid of the mappings and all user-space */
extern void mmput(struct mm_struct *);
/* Grab a reference to a task's mm, if it is not already going away */
extern struct mm_struct *get_task_mm(struct task_struct *task);
2347 2348 2349 2350 2351 2352
/*
 * Grab a reference to a task's mm, if it is not already going away
 * and ptrace_may_access with the mode parameter passed to it
 * succeeds.
 */
extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
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/* Remove the current tasks stale references to the old mm_struct */
extern void mm_release(struct task_struct *, struct mm_struct *);

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extern int copy_thread(unsigned long, unsigned long, unsigned long,
2357
			struct task_struct *);
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extern void flush_thread(void);
extern void exit_thread(void);

extern void exit_files(struct task_struct *);
2362
extern void __cleanup_sighand(struct sighand_struct *);
2363

L
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extern void exit_itimers(struct signal_struct *);
2365
extern void flush_itimer_signals(void);
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2366

2367
extern void do_group_exit(int);
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extern int allow_signal(int);
extern int disallow_signal(int);

2372
extern int do_execve(struct filename *,
2373
		     const char __user * const __user *,
2374
		     const char __user * const __user *);
2375
extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2376
struct task_struct *fork_idle(int);
2377
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
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2379
extern void set_task_comm(struct task_struct *tsk, const char *from);
2380
extern char *get_task_comm(char *to, struct task_struct *tsk);
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#ifdef CONFIG_SMP
2383
void scheduler_ipi(void);
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2384
extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
L
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2385
#else
2386
static inline void scheduler_ipi(void) { }
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static inline unsigned long wait_task_inactive(struct task_struct *p,
					       long match_state)
{
	return 1;
}
L
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2392 2393
#endif

2394 2395
#define next_task(p) \
	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
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#define for_each_process(p) \
	for (p = &init_task ; (p = next_task(p)) != &init_task ; )

2400
extern bool current_is_single_threaded(void);
D
David Howells 已提交
2401

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/*
 * Careful: do_each_thread/while_each_thread is a double loop so
 *          'break' will not work as expected - use goto instead.
 */
#define do_each_thread(g, t) \
	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do

#define while_each_thread(g, t) \
	while ((t = next_thread(t)) != g)

2412 2413 2414 2415 2416 2417 2418 2419 2420 2421
#define __for_each_thread(signal, t)	\
	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)

#define for_each_thread(p, t)		\
	__for_each_thread((p)->signal, t)

/* Careful: this is a double loop, 'break' won't work as expected. */
#define for_each_process_thread(p, t)	\
	for_each_process(p) for_each_thread(p, t)

2422 2423
static inline int get_nr_threads(struct task_struct *tsk)
{
2424
	return tsk->signal->nr_threads;
2425 2426
}

2427 2428 2429 2430
static inline bool thread_group_leader(struct task_struct *p)
{
	return p->exit_signal >= 0;
}
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2432 2433 2434 2435 2436 2437
/* Do to the insanities of de_thread it is possible for a process
 * to have the pid of the thread group leader without actually being
 * the thread group leader.  For iteration through the pids in proc
 * all we care about is that we have a task with the appropriate
 * pid, we don't actually care if we have the right task.
 */
2438
static inline bool has_group_leader_pid(struct task_struct *p)
2439
{
2440
	return task_pid(p) == p->signal->leader_pid;
2441 2442
}

2443
static inline
2444
bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2445
{
2446
	return p1->signal == p2->signal;
2447 2448
}

2449
static inline struct task_struct *next_thread(const struct task_struct *p)
O
Oleg Nesterov 已提交
2450
{
2451 2452
	return list_entry_rcu(p->thread_group.next,
			      struct task_struct, thread_group);
O
Oleg Nesterov 已提交
2453 2454
}

A
Alexey Dobriyan 已提交
2455
static inline int thread_group_empty(struct task_struct *p)
L
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2456
{
O
Oleg Nesterov 已提交
2457
	return list_empty(&p->thread_group);
L
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2458 2459 2460 2461 2462 2463
}

#define delay_group_leader(p) \
		(thread_group_leader(p) && !thread_group_empty(p))

/*
2464
 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2465
 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2466
 * pins the final release of task.io_context.  Also protects ->cpuset and
O
Oleg Nesterov 已提交
2467
 * ->cgroup.subsys[]. And ->vfork_done.
L
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2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482
 *
 * Nests both inside and outside of read_lock(&tasklist_lock).
 * It must not be nested with write_lock_irq(&tasklist_lock),
 * neither inside nor outside.
 */
static inline void task_lock(struct task_struct *p)
{
	spin_lock(&p->alloc_lock);
}

static inline void task_unlock(struct task_struct *p)
{
	spin_unlock(&p->alloc_lock);
}

2483
extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2484 2485
							unsigned long *flags);

2486 2487 2488 2489 2490 2491 2492 2493 2494
static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
						       unsigned long *flags)
{
	struct sighand_struct *ret;

	ret = __lock_task_sighand(tsk, flags);
	(void)__cond_lock(&tsk->sighand->siglock, ret);
	return ret;
}
2495

2496 2497 2498 2499 2500 2501
static inline void unlock_task_sighand(struct task_struct *tsk,
						unsigned long *flags)
{
	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
}

2502
#ifdef CONFIG_CGROUPS
2503
static inline void threadgroup_change_begin(struct task_struct *tsk)
2504
{
2505
	down_read(&tsk->signal->group_rwsem);
2506
}
2507
static inline void threadgroup_change_end(struct task_struct *tsk)
2508
{
2509
	up_read(&tsk->signal->group_rwsem);
2510
}
2511 2512 2513 2514 2515 2516 2517

/**
 * threadgroup_lock - lock threadgroup
 * @tsk: member task of the threadgroup to lock
 *
 * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
 * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2518 2519
 * change ->group_leader/pid.  This is useful for cases where the threadgroup
 * needs to stay stable across blockable operations.
2520 2521 2522 2523 2524
 *
 * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
 * synchronization.  While held, no new task will be added to threadgroup
 * and no existing live task will have its PF_EXITING set.
 *
2525 2526
 * de_thread() does threadgroup_change_{begin|end}() when a non-leader
 * sub-thread becomes a new leader.
2527
 */
2528
static inline void threadgroup_lock(struct task_struct *tsk)
2529
{
2530
	down_write(&tsk->signal->group_rwsem);
2531
}
2532 2533 2534 2535 2536 2537 2538

/**
 * threadgroup_unlock - unlock threadgroup
 * @tsk: member task of the threadgroup to unlock
 *
 * Reverse threadgroup_lock().
 */
2539
static inline void threadgroup_unlock(struct task_struct *tsk)
2540
{
2541
	up_write(&tsk->signal->group_rwsem);
2542 2543
}
#else
2544 2545 2546 2547
static inline void threadgroup_change_begin(struct task_struct *tsk) {}
static inline void threadgroup_change_end(struct task_struct *tsk) {}
static inline void threadgroup_lock(struct task_struct *tsk) {}
static inline void threadgroup_unlock(struct task_struct *tsk) {}
2548 2549
#endif

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2550 2551
#ifndef __HAVE_THREAD_FUNCTIONS

R
Roman Zippel 已提交
2552 2553
#define task_thread_info(task)	((struct thread_info *)(task)->stack)
#define task_stack_page(task)	((task)->stack)
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2555 2556 2557 2558 2559 2560 2561 2562
static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
{
	*task_thread_info(p) = *task_thread_info(org);
	task_thread_info(p)->task = p;
}

static inline unsigned long *end_of_stack(struct task_struct *p)
{
R
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2563
	return (unsigned long *)(task_thread_info(p) + 1);
2564 2565
}

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2566 2567
#endif

2568 2569 2570 2571 2572 2573 2574
static inline int object_is_on_stack(void *obj)
{
	void *stack = task_stack_page(current);

	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
}

2575 2576
extern void thread_info_cache_init(void);

2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589
#ifdef CONFIG_DEBUG_STACK_USAGE
static inline unsigned long stack_not_used(struct task_struct *p)
{
	unsigned long *n = end_of_stack(p);

	do { 	/* Skip over canary */
		n++;
	} while (!*n);

	return (unsigned long)n - (unsigned long)end_of_stack(p);
}
#endif

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/* set thread flags in other task's structures
 * - see asm/thread_info.h for TIF_xxxx flags available
 */
static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
{
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	set_ti_thread_flag(task_thread_info(tsk), flag);
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2596 2597 2598 2599
}

static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
{
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	clear_ti_thread_flag(task_thread_info(tsk), flag);
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}

static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
{
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2605
	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
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2606 2607 2608 2609
}

static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
{
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2610
	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
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2611 2612 2613 2614
}

static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
{
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2615
	return test_ti_thread_flag(task_thread_info(tsk), flag);
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}

static inline void set_tsk_need_resched(struct task_struct *tsk)
{
	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
}

static inline void clear_tsk_need_resched(struct task_struct *tsk)
{
	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
}

2628 2629 2630 2631 2632
static inline int test_tsk_need_resched(struct task_struct *tsk)
{
	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
}

2633 2634 2635 2636 2637 2638
static inline int restart_syscall(void)
{
	set_tsk_thread_flag(current, TIF_SIGPENDING);
	return -ERESTARTNOINTR;
}

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2639 2640 2641 2642
static inline int signal_pending(struct task_struct *p)
{
	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
}
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Matthew Wilcox 已提交
2643

2644 2645 2646 2647
static inline int __fatal_signal_pending(struct task_struct *p)
{
	return unlikely(sigismember(&p->pending.signal, SIGKILL));
}
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2648 2649 2650 2651 2652 2653

static inline int fatal_signal_pending(struct task_struct *p)
{
	return signal_pending(p) && __fatal_signal_pending(p);
}

2654 2655 2656 2657 2658 2659 2660 2661 2662 2663
static inline int signal_pending_state(long state, struct task_struct *p)
{
	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
		return 0;
	if (!signal_pending(p))
		return 0;

	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
}

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/*
 * cond_resched() and cond_resched_lock(): latency reduction via
 * explicit rescheduling in places that are safe. The return
 * value indicates whether a reschedule was done in fact.
 * cond_resched_lock() will drop the spinlock before scheduling,
 * cond_resched_softirq() will enable bhs before scheduling.
 */
2671
extern int _cond_resched(void);
2672

2673 2674 2675 2676
#define cond_resched() ({			\
	__might_sleep(__FILE__, __LINE__, 0);	\
	_cond_resched();			\
})
2677

2678 2679
extern int __cond_resched_lock(spinlock_t *lock);

2680
#ifdef CONFIG_PREEMPT_COUNT
2681
#define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2682
#else
2683
#define PREEMPT_LOCK_OFFSET	0
2684
#endif
2685

2686
#define cond_resched_lock(lock) ({				\
2687
	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
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	__cond_resched_lock(lock);				\
})

extern int __cond_resched_softirq(void);

2693 2694 2695
#define cond_resched_softirq() ({					\
	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
	__cond_resched_softirq();					\
2696
})
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static inline void cond_resched_rcu(void)
{
#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
	rcu_read_unlock();
	cond_resched();
	rcu_read_lock();
#endif
}

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/*
 * Does a critical section need to be broken due to another
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 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
 * but a general need for low latency)
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 */
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static inline int spin_needbreak(spinlock_t *lock)
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{
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#ifdef CONFIG_PREEMPT
	return spin_is_contended(lock);
#else
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	return 0;
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#endif
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}

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/*
 * Idle thread specific functions to determine the need_resched
 * polling state. We have two versions, one based on TS_POLLING in
 * thread_info.status and one based on TIF_POLLING_NRFLAG in
 * thread_info.flags
 */
#ifdef TS_POLLING
static inline int tsk_is_polling(struct task_struct *p)
{
	return task_thread_info(p)->status & TS_POLLING;
}
2732
static inline void __current_set_polling(void)
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{
	current_thread_info()->status |= TS_POLLING;
}

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static inline bool __must_check current_set_polling_and_test(void)
{
	__current_set_polling();

	/*
	 * Polling state must be visible before we test NEED_RESCHED,
	 * paired by resched_task()
	 */
	smp_mb();

	return unlikely(tif_need_resched());
}

static inline void __current_clr_polling(void)
2751 2752
{
	current_thread_info()->status &= ~TS_POLLING;
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}

static inline bool __must_check current_clr_polling_and_test(void)
{
	__current_clr_polling();

	/*
	 * Polling state must be visible before we test NEED_RESCHED,
	 * paired by resched_task()
	 */
	smp_mb();

	return unlikely(tif_need_resched());
2766
}
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#elif defined(TIF_POLLING_NRFLAG)
static inline int tsk_is_polling(struct task_struct *p)
{
	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
}
2772 2773

static inline void __current_set_polling(void)
2774 2775 2776 2777
{
	set_thread_flag(TIF_POLLING_NRFLAG);
}

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static inline bool __must_check current_set_polling_and_test(void)
{
	__current_set_polling();

	/*
	 * Polling state must be visible before we test NEED_RESCHED,
	 * paired by resched_task()
	 *
	 * XXX: assumes set/clear bit are identical barrier wise.
	 */
	smp_mb__after_clear_bit();

	return unlikely(tif_need_resched());
}

static inline void __current_clr_polling(void)
2794 2795 2796
{
	clear_thread_flag(TIF_POLLING_NRFLAG);
}
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static inline bool __must_check current_clr_polling_and_test(void)
{
	__current_clr_polling();

	/*
	 * Polling state must be visible before we test NEED_RESCHED,
	 * paired by resched_task()
	 */
	smp_mb__after_clear_bit();

	return unlikely(tif_need_resched());
}

2811 2812
#else
static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
static inline void __current_set_polling(void) { }
static inline void __current_clr_polling(void) { }

static inline bool __must_check current_set_polling_and_test(void)
{
	return unlikely(tif_need_resched());
}
static inline bool __must_check current_clr_polling_and_test(void)
{
	return unlikely(tif_need_resched());
}
2824 2825
#endif

2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840
static inline void current_clr_polling(void)
{
	__current_clr_polling();

	/*
	 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
	 * Once the bit is cleared, we'll get IPIs with every new
	 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
	 * fold.
	 */
	smp_mb(); /* paired with resched_task() */

	preempt_fold_need_resched();
}

2841 2842 2843 2844 2845
static __always_inline bool need_resched(void)
{
	return unlikely(tif_need_resched());
}

2846 2847 2848
/*
 * Thread group CPU time accounting.
 */
2849
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2850
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2851

2852
static inline void thread_group_cputime_init(struct signal_struct *sig)
2853
{
2854
	raw_spin_lock_init(&sig->cputimer.lock);
2855 2856
}

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/*
 * Reevaluate whether the task has signals pending delivery.
 * Wake the task if so.
 * This is required every time the blocked sigset_t changes.
 * callers must hold sighand->siglock.
 */
extern void recalc_sigpending_and_wake(struct task_struct *t);
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extern void recalc_sigpending(void);

2866 2867 2868 2869 2870 2871 2872 2873 2874 2875
extern void signal_wake_up_state(struct task_struct *t, unsigned int state);

static inline void signal_wake_up(struct task_struct *t, bool resume)
{
	signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
}
static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
{
	signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
}
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/*
 * Wrappers for p->thread_info->cpu access. No-op on UP.
 */
#ifdef CONFIG_SMP

static inline unsigned int task_cpu(const struct task_struct *p)
{
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	return task_thread_info(p)->cpu;
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}

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Ingo Molnar 已提交
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static inline int task_node(const struct task_struct *p)
{
	return cpu_to_node(task_cpu(p));
}

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extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
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#else

static inline unsigned int task_cpu(const struct task_struct *p)
{
	return 0;
}

static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
{
}

#endif /* CONFIG_SMP */

2907 2908
extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2909

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#ifdef CONFIG_CGROUP_SCHED
2911
extern struct task_group root_task_group;
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#endif /* CONFIG_CGROUP_SCHED */
2913

2914 2915 2916
extern int task_can_switch_user(struct user_struct *up,
					struct task_struct *tsk);

2917 2918 2919
#ifdef CONFIG_TASK_XACCT
static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
{
2920
	tsk->ioac.rchar += amt;
2921 2922 2923 2924
}

static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
{
2925
	tsk->ioac.wchar += amt;
2926 2927 2928 2929
}

static inline void inc_syscr(struct task_struct *tsk)
{
2930
	tsk->ioac.syscr++;
2931 2932 2933 2934
}

static inline void inc_syscw(struct task_struct *tsk)
{
2935
	tsk->ioac.syscw++;
2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954
}
#else
static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
{
}

static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
{
}

static inline void inc_syscr(struct task_struct *tsk)
{
}

static inline void inc_syscw(struct task_struct *tsk)
{
}
#endif

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#ifndef TASK_SIZE_OF
#define TASK_SIZE_OF(tsk)	TASK_SIZE
#endif

2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971
#ifdef CONFIG_MM_OWNER
extern void mm_update_next_owner(struct mm_struct *mm);
extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
#else
static inline void mm_update_next_owner(struct mm_struct *mm)
{
}

static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
{
}
#endif /* CONFIG_MM_OWNER */

2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993
static inline unsigned long task_rlimit(const struct task_struct *tsk,
		unsigned int limit)
{
	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
}

static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
		unsigned int limit)
{
	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
}

static inline unsigned long rlimit(unsigned int limit)
{
	return task_rlimit(current, limit);
}

static inline unsigned long rlimit_max(unsigned int limit)
{
	return task_rlimit_max(current, limit);
}

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#endif