blob: dec5827c77422ebbd8e7f0238cdf7f34e08cb906 [file] [log] [blame]
#ifndef _LINUX_SCHED_H
#define _LINUX_SCHED_H
#include <asm/param.h> /* for HZ */
#include <linux/config.h>
#include <linux/capability.h>
#include <linux/threads.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/timex.h>
#include <linux/jiffies.h>
#include <linux/rbtree.h>
#include <linux/thread_info.h>
#include <linux/cpumask.h>
#include <linux/errno.h>
#include <linux/nodemask.h>
#include <asm/system.h>
#include <asm/semaphore.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/mmu.h>
#include <asm/cputime.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/signal.h>
#include <linux/securebits.h>
#include <linux/fs_struct.h>
#include <linux/compiler.h>
#include <linux/completion.h>
#include <linux/pid.h>
#include <linux/percpu.h>
#include <linux/topology.h>
#include <linux/seccomp.h>
struct exec_domain;
* cloning flags:
#define CSIGNAL 0x000000ff /* signal mask to be sent at exit */
#define CLONE_VM 0x00000100 /* set if VM shared between processes */
#define CLONE_FS 0x00000200 /* set if fs info shared between processes */
#define CLONE_FILES 0x00000400 /* set if open files shared between processes */
#define CLONE_SIGHAND 0x00000800 /* set if signal handlers and blocked signals shared */
#define CLONE_PTRACE 0x00002000 /* set if we want to let tracing continue on the child too */
#define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */
#define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */
#define CLONE_THREAD 0x00010000 /* Same thread group? */
#define CLONE_NEWNS 0x00020000 /* New namespace group? */
#define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */
#define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */
#define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */
#define CLONE_CHILD_CLEARTID 0x00200000 /* clear the TID in the child */
#define CLONE_DETACHED 0x00400000 /* Unused, ignored */
#define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */
#define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
#define CLONE_STOPPED 0x02000000 /* Start in stopped state */
* List of flags we want to share for kernel threads,
* if only because they are not used by them anyway.
* 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 */
#define FSHIFT 11 /* nr of bits of precision */
#define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
#define LOAD_FREQ (5*HZ) /* 5 sec intervals */
#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;
extern int last_pid;
DECLARE_PER_CPU(unsigned long, process_counts);
extern int nr_processes(void);
extern unsigned long nr_running(void);
extern unsigned long nr_uninterruptible(void);
extern unsigned long nr_iowait(void);
#include <linux/time.h>
#include <linux/param.h>
#include <linux/resource.h>
#include <linux/timer.h>
#include <asm/processor.h>
#define TASK_RUNNING 0
#define TASK_STOPPED 4
#define TASK_TRACED 8
#define EXIT_ZOMBIE 16
#define EXIT_DEAD 32
#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))
#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
* Scheduling policies
#define SCHED_NORMAL 0
#define SCHED_FIFO 1
#define SCHED_RR 2
struct sched_param {
int sched_priority;
#ifdef __KERNEL__
#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;
typedef struct task_struct task_t;
extern void sched_init(void);
extern void sched_init_smp(void);
extern void init_idle(task_t *idle, int cpu);
extern cpumask_t nohz_cpu_mask;
extern void show_state(void);
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);
/* Attach to any functions which should be ignored in wchan output. */
#define __sched __attribute__((__section__(".sched.text")))
/* Is this address in the __sched functions? */
extern int in_sched_functions(unsigned long addr);
extern signed long FASTCALL(schedule_timeout(signed long timeout));
asmlinkage void schedule(void);
struct namespace;
/* Maximum number of active map areas.. This is a random (large) number */
extern int sysctl_max_map_count;
#include <linux/aio.h>
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);
extern void arch_unmap_area(struct mm_struct *, unsigned long);
extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
#define set_mm_counter(mm, member, value) (mm)->_##member = (value)
#define get_mm_counter(mm, member) ((mm)->_##member)
#define add_mm_counter(mm, member, value) (mm)->_##member += (value)
#define inc_mm_counter(mm, member) (mm)->_##member++
#define dec_mm_counter(mm, member) (mm)->_##member--
typedef unsigned long mm_counter_t;
struct mm_struct {
struct vm_area_struct * mmap; /* list of VMAs */
struct rb_root mm_rb;
struct vm_area_struct * mmap_cache; /* last find_vma result */
unsigned long (*get_unmapped_area) (struct file *filp,
unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags);
void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
unsigned long mmap_base; /* base of mmap area */
unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */
unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */
pgd_t * pgd;
atomic_t mm_users; /* How many users with user space? */
atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
int map_count; /* number of VMAs */
struct rw_semaphore mmap_sem;
spinlock_t page_table_lock; /* Protects page tables and some counters */
struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
* together off init_mm.mmlist, and are protected
* by mmlist_lock
unsigned long start_code, end_code, start_data, end_data;
unsigned long start_brk, brk, start_stack;
unsigned long arg_start, arg_end, env_start, env_end;
unsigned long total_vm, locked_vm, shared_vm;
unsigned long exec_vm, stack_vm, reserved_vm, def_flags, nr_ptes;
/* Special counters protected by the page_table_lock */
mm_counter_t _rss;
mm_counter_t _anon_rss;
unsigned long saved_auxv[42]; /* for /proc/PID/auxv */
unsigned dumpable:2;
cpumask_t cpu_vm_mask;
/* Architecture-specific MM context */
mm_context_t context;
/* Token based thrashing protection. */
unsigned long swap_token_time;
char recent_pagein;
/* coredumping support */
int core_waiters;
struct completion *core_startup_done, core_done;
/* aio bits */
rwlock_t ioctx_list_lock;
struct kioctx *ioctx_list;
struct kioctx default_kioctx;
unsigned long hiwater_rss; /* High-water RSS usage */
unsigned long hiwater_vm; /* High-water virtual memory usage */
struct sighand_struct {
atomic_t count;
struct k_sigaction action[_NSIG];
spinlock_t siglock;
* NOTE! "signal_struct" does not have it's own
* 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 {
atomic_t count;
atomic_t live;
wait_queue_head_t wait_chldexit; /* for wait4() */
/* current thread group signal load-balancing target: */
task_t *curr_target;
/* 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.
struct task_struct *group_exit_task;
int notify_count;
/* thread group stop support, overloads group_exit_code too */
int group_stop_count;
unsigned int flags; /* see SIGNAL_* flags below */
/* POSIX.1b Interval Timers */
struct list_head posix_timers;
/* ITIMER_REAL timer for the process */
struct timer_list real_timer;
unsigned long it_real_value, it_real_incr;
/* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
cputime_t it_prof_expires, it_virt_expires;
cputime_t it_prof_incr, it_virt_incr;
/* job control IDs */
pid_t pgrp;
pid_t tty_old_pgrp;
pid_t session;
/* boolean value for session group leader */
int leader;
struct tty_struct *tty; /* NULL if no tty */
* 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.
cputime_t utime, stime, cutime, cstime;
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
* Cumulative ns of scheduled CPU time for 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 sched_time;
* 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];
struct list_head cpu_timers[3];
/* keep the process-shared keyrings here so that they do the right
* thing in threads created with CLONE_THREAD */
struct key *session_keyring; /* keyring inherited over fork */
struct key *process_keyring; /* keyring private to this process */
/* Context switch must be unlocked if interrupts are to be enabled */
* Bits in flags field of signal_struct.
#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
#define SIGNAL_STOP_DEQUEUED 0x00000002 /* stop signal dequeued */
#define SIGNAL_STOP_CONTINUED 0x00000004 /* SIGCONT since WCONTINUED reap */
#define SIGNAL_GROUP_EXIT 0x00000008 /* group exit in progress */
* Priority of a process goes from 0..MAX_PRIO-1, valid RT
* priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL tasks are
* in the range MAX_RT_PRIO..MAX_PRIO-1. Priority values
* are inverted: lower p->prio value means higher priority.
* The MAX_USER_RT_PRIO value allows the actual maximum
* RT priority to be separate from the value exported to
* user-space. This allows kernel threads to set their
* priority to a value higher than any user task. Note:
* MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
#define MAX_USER_RT_PRIO 100
#define MAX_PRIO (MAX_RT_PRIO + 40)
#define rt_task(p) (unlikely((p)->prio < MAX_RT_PRIO))
* 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? */
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? */
/* protected by mq_lock */
unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
unsigned long locked_shm; /* How many pages of mlocked shm ? */
struct key *uid_keyring; /* UID specific keyring */
struct key *session_keyring; /* UID's default session keyring */
/* Hash table maintenance information */
struct list_head uidhash_list;
uid_t uid;
extern struct user_struct *find_user(uid_t);
extern struct user_struct root_user;
#define INIT_USER (&root_user)
typedef struct prio_array prio_array_t;
struct backing_dev_info;
struct reclaim_state;
struct sched_info {
/* cumulative counters */
unsigned long cpu_time, /* time spent on the cpu */
run_delay, /* time spent waiting on a runqueue */
pcnt; /* # of timeslices run on this cpu */
/* timestamps */
unsigned long last_arrival, /* when we last ran on a cpu */
last_queued; /* when we were last queued to run */
extern struct file_operations proc_schedstat_operations;
enum idle_type
* sched-domains (multiprocessor balancing) declarations:
#define SCHED_LOAD_SCALE 128UL /* increase resolution of load */
#define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */
#define SD_BALANCE_NEWIDLE 2 /* Balance when about to become idle */
#define SD_BALANCE_EXEC 4 /* Balance on exec */
#define SD_BALANCE_FORK 8 /* Balance on fork, clone */
#define SD_WAKE_IDLE 16 /* Wake to idle CPU on task wakeup */
#define SD_WAKE_AFFINE 32 /* Wake task to waking CPU */
#define SD_WAKE_BALANCE 64 /* Perform balancing at task wakeup */
#define SD_SHARE_CPUPOWER 128 /* Domain members share cpu power */
struct sched_group {
struct sched_group *next; /* Must be a circular list */
cpumask_t cpumask;
* CPU power of this group, SCHED_LOAD_SCALE being max power for a
* single CPU. This is read only (except for setup, hotplug CPU).
unsigned long cpu_power;
struct sched_domain {
/* These fields must be setup */
struct sched_domain *parent; /* top domain must be null terminated */
struct sched_group *groups; /* the balancing groups of the domain */
cpumask_t span; /* span of all CPUs in this 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 long long cache_hot_time; /* Task considered cache hot (ns) */
unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
unsigned int per_cpu_gain; /* CPU % gained by adding domain cpus */
unsigned int busy_idx;
unsigned int idle_idx;
unsigned int newidle_idx;
unsigned int wake_idx;
unsigned int forkexec_idx;
int flags; /* See SD_* */
/* 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 */
/* load_balance() stats */
unsigned long lb_cnt[MAX_IDLE_TYPES];
unsigned long lb_failed[MAX_IDLE_TYPES];
unsigned long lb_balanced[MAX_IDLE_TYPES];
unsigned long lb_imbalance[MAX_IDLE_TYPES];
unsigned long lb_gained[MAX_IDLE_TYPES];
unsigned long lb_hot_gained[MAX_IDLE_TYPES];
unsigned long lb_nobusyg[MAX_IDLE_TYPES];
unsigned long lb_nobusyq[MAX_IDLE_TYPES];
/* Active load balancing */
unsigned long alb_cnt;
unsigned long alb_failed;
unsigned long alb_pushed;
/* SD_BALANCE_EXEC stats */
unsigned long sbe_cnt;
unsigned long sbe_balanced;
unsigned long sbe_pushed;
/* SD_BALANCE_FORK stats */
unsigned long sbf_cnt;
unsigned long sbf_balanced;
unsigned long sbf_pushed;
/* try_to_wake_up() stats */
unsigned long ttwu_wake_remote;
unsigned long ttwu_move_affine;
unsigned long ttwu_move_balance;
extern void partition_sched_domains(cpumask_t *partition1,
cpumask_t *partition2);
/* Useful helpers that arch setup code may use. Defined in kernel/sched.c */
extern cpumask_t cpu_isolated_map;
extern void init_sched_build_groups(struct sched_group groups[],
cpumask_t span, int (*group_fn)(int cpu));
extern void cpu_attach_domain(struct sched_domain *sd, int cpu);
#endif /* CONFIG_SMP */
struct io_context; /* See blkdev.h */
void exit_io_context(void);
struct cpuset;
#define NGROUPS_SMALL 32
#define NGROUPS_PER_BLOCK ((int)(PAGE_SIZE / sizeof(gid_t)))
struct group_info {
int ngroups;
atomic_t usage;
gid_t small_block[NGROUPS_SMALL];
int nblocks;
gid_t *blocks[0];
* get_group_info() must be called with the owning task locked (via task_lock())
* when task != current. The reason being that the vast majority of callers are
* looking at current->group_info, which can not be changed except by the
* current task. Changing current->group_info requires the task lock, too.
#define get_group_info(group_info) do { \
atomic_inc(&(group_info)->usage); \
} while (0)
#define put_group_info(group_info) do { \
if (atomic_dec_and_test(&(group_info)->usage)) \
groups_free(group_info); \
} while (0)
extern struct group_info *groups_alloc(int gidsetsize);
extern void groups_free(struct group_info *group_info);
extern int set_current_groups(struct group_info *group_info);
extern int groups_search(struct group_info *group_info, gid_t grp);
/* access the groups "array" with this macro */
#define GROUP_AT(gi, i) \
struct audit_context; /* See audit.c */
struct mempolicy;
struct task_struct {
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
struct thread_info *thread_info;
atomic_t usage;
unsigned long flags; /* per process flags, defined below */
unsigned long ptrace;
int lock_depth; /* BKL lock depth */
#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
int oncpu;
int prio, static_prio;
struct list_head run_list;
prio_array_t *array;
unsigned short ioprio;
unsigned long sleep_avg;
unsigned long long timestamp, last_ran;
unsigned long long sched_time; /* sched_clock time spent running */
int activated;
unsigned long policy;
cpumask_t cpus_allowed;
unsigned int time_slice, first_time_slice;
struct sched_info sched_info;
struct list_head tasks;
* ptrace_list/ptrace_children forms the list of my children
* that were stolen by a ptracer.
struct list_head ptrace_children;
struct list_head ptrace_list;
struct mm_struct *mm, *active_mm;
/* task state */
struct linux_binfmt *binfmt;
long exit_state;
int exit_code, exit_signal;
int pdeath_signal; /* The signal sent when the parent dies */
/* ??? */
unsigned long personality;
unsigned did_exec:1;
pid_t pid;
pid_t tgid;
* pointers to (original) parent process, youngest child, younger sibling,
* older sibling, respectively. (p->father can be replaced with
* p->parent->pid)
struct task_struct *real_parent; /* real parent process (when being debugged) */
struct task_struct *parent; /* parent process */
* children/sibling forms the list of my children plus the
* tasks I'm ptracing.
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 */
/* PID/PID hash table linkage. */
struct pid pids[PIDTYPE_MAX];
struct completion *vfork_done; /* for vfork() */
int __user *set_child_tid; /* CLONE_CHILD_SETTID */
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
unsigned long rt_priority;
cputime_t utime, stime;
unsigned long nvcsw, nivcsw; /* context switch counts */
struct timespec start_time;
/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
unsigned long min_flt, maj_flt;
cputime_t it_prof_expires, it_virt_expires;
unsigned long long it_sched_expires;
struct list_head cpu_timers[3];
/* process credentials */
uid_t uid,euid,suid,fsuid;
gid_t gid,egid,sgid,fsgid;
struct group_info *group_info;
kernel_cap_t cap_effective, cap_inheritable, cap_permitted;
unsigned keep_capabilities:1;
struct user_struct *user;
struct key *thread_keyring; /* keyring private to this thread */
unsigned char jit_keyring; /* default keyring to attach requested keys to */
int oomkilladj; /* OOM kill score adjustment (bit shift). */
char comm[TASK_COMM_LEN]; /* executable name excluding path
- access with [gs]et_task_comm (which lock
it with task_lock())
- initialized normally by flush_old_exec */
/* file system info */
int link_count, total_link_count;
/* ipc stuff */
struct sysv_sem sysvsem;
/* CPU-specific state of this task */
struct thread_struct thread;
/* filesystem information */
struct fs_struct *fs;
/* open file information */
struct files_struct *files;
/* namespace */
struct namespace *namespace;
/* signal handlers */
struct signal_struct *signal;
struct sighand_struct *sighand;
sigset_t blocked, real_blocked;
struct sigpending pending;
unsigned long sas_ss_sp;
size_t sas_ss_size;
int (*notifier)(void *priv);
void *notifier_data;
sigset_t *notifier_mask;
void *security;
struct audit_context *audit_context;
seccomp_t seccomp;
/* Thread group tracking */
u32 parent_exec_id;
u32 self_exec_id;
/* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
spinlock_t alloc_lock;
/* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
spinlock_t proc_lock;
/* journalling filesystem info */
void *journal_info;
/* VM state */
struct reclaim_state *reclaim_state;
struct dentry *proc_dentry;
struct backing_dev_info *backing_dev_info;
struct io_context *io_context;
unsigned long ptrace_message;
siginfo_t *last_siginfo; /* For ptrace use. */
* current io wait handle: wait queue entry to use for io waits
* If this thread is processing aio, this points at the waitqueue
* inside the currently handled kiocb. It may be NULL (i.e. default
* to a stack based synchronous wait) if its doing sync IO.
wait_queue_t *io_wait;
/* i/o counters(bytes read/written, #syscalls */
u64 rchar, wchar, syscr, syscw;
u64 acct_rss_mem1; /* accumulated rss usage */
u64 acct_vm_mem1; /* accumulated virtual memory usage */
clock_t acct_stimexpd; /* clock_t-converted stime since last update */
struct mempolicy *mempolicy;
short il_next;
struct cpuset *cpuset;
nodemask_t mems_allowed;
int cpuset_mems_generation;
atomic_t fs_excl; /* holding fs exclusive resources */
static inline pid_t process_group(struct task_struct *tsk)
return tsk->signal->pgrp;
* 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.
static inline int pid_alive(struct task_struct *p)
return p->pids[PIDTYPE_PID].nr != 0;
extern void free_task(struct task_struct *tsk);
extern void __put_task_struct(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
#define put_task_struct(tsk) \
do { if (atomic_dec_and_test(&(tsk)->usage)) __put_task_struct(tsk); } while(0)
* Per process flags
#define PF_ALIGNWARN 0x00000001 /* Print alignment warning msgs */
/* Not implemented yet, only for 486*/
#define PF_STARTING 0x00000002 /* being created */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_DEAD 0x00000008 /* Dead */
#define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
#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 */
#define PF_FLUSHER 0x00001000 /* responsible for disk writeback */
#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
#define PF_FREEZE 0x00004000 /* this task is being frozen for suspend now */
#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 */
#define PF_SWAPOFF 0x00080000 /* I am in swapoff */
#define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
#define PF_SYNCWRITE 0x00200000 /* I am doing a sync write */
#define PF_BORROWED_MM 0x00400000 /* I am a kthread doing use_mm */
#define PF_RANDOMIZE 0x00800000 /* randomize virtual address space */
* 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)
extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask)
if (!cpus_intersects(new_mask, cpu_online_map))
return -EINVAL;
return 0;
extern unsigned long long sched_clock(void);
extern unsigned long long current_sched_time(const task_t *current_task);
/* sched_exec is called by processes performing an exec */
extern void sched_exec(void);
#define sched_exec() {}
extern void idle_task_exit(void);
static inline void idle_task_exit(void) {}
extern void sched_idle_next(void);
extern void set_user_nice(task_t *p, long nice);
extern int task_prio(const task_t *p);
extern int task_nice(const task_t *p);
extern int can_nice(const task_t *p, const int nice);
extern int task_curr(const task_t *p);
extern int idle_cpu(int cpu);
extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
extern task_t *idle_task(int cpu);
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)];
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*)));
extern union thread_union init_thread_union;
extern struct task_struct init_task;
extern struct mm_struct init_mm;
#define find_task_by_pid(nr) find_task_by_pid_type(PIDTYPE_PID, nr)
extern struct task_struct *find_task_by_pid_type(int type, int pid);
extern void set_special_pids(pid_t session, pid_t pgrp);
extern void __set_special_pids(pid_t session, pid_t pgrp);
/* per-UID process charging. */
extern struct user_struct * alloc_uid(uid_t);
static inline struct user_struct *get_uid(struct user_struct *u)
return u;
extern void free_uid(struct user_struct *);
extern void switch_uid(struct user_struct *);
#include <asm/current.h>
extern void do_timer(struct pt_regs *);
extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
extern int FASTCALL(wake_up_process(struct task_struct * tsk));
extern void FASTCALL(wake_up_new_task(struct task_struct * tsk,
unsigned long clone_flags));
extern void kick_process(struct task_struct *tsk);
static inline void kick_process(struct task_struct *tsk) { }
extern void FASTCALL(sched_fork(task_t * p, int clone_flags));
extern void FASTCALL(sched_exit(task_t * p));
extern int in_group_p(gid_t);
extern int in_egroup_p(gid_t);
extern void proc_caches_init(void);
extern void flush_signals(struct task_struct *);
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;
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 send_group_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 *);
extern int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp);
extern int kill_pg_info(int, struct siginfo *, pid_t);
extern int kill_proc_info(int, struct siginfo *, pid_t);
extern void do_notify_parent(struct task_struct *, int);
extern void force_sig(int, struct task_struct *);
extern void force_sig_specific(int, struct task_struct *);
extern int send_sig(int, struct task_struct *, int);
extern void zap_other_threads(struct task_struct *p);
extern int kill_pg(pid_t, int, int);
extern int kill_sl(pid_t, int, int);
extern int kill_proc(pid_t, int, int);
extern struct sigqueue *sigqueue_alloc(void);
extern void sigqueue_free(struct sigqueue *);
extern int send_sigqueue(int, struct sigqueue *, struct task_struct *);
extern int send_group_sigqueue(int, struct sigqueue *, struct task_struct *);
extern int do_sigaction(int, const struct k_sigaction *, struct k_sigaction *);
extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
/* 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)
/* True if we are on the alternate signal stack. */
static inline int on_sig_stack(unsigned long sp)
return (sp - current->sas_ss_sp < current->sas_ss_size);
static inline int sas_ss_flags(unsigned long sp)
return (current->sas_ss_size == 0 ? SS_DISABLE
: on_sig_stack(sp) ? SS_ONSTACK : 0);
/* code is in security.c */
extern int capable(int cap);
static inline int capable(int cap)
if (cap_raised(current->cap_effective, cap)) {
current->flags |= PF_SUPERPRIV;
return 1;
return 0;
* Routines for handling mm_structs
extern struct mm_struct * mm_alloc(void);
/* mmdrop drops the mm and the page tables */
extern void FASTCALL(__mmdrop(struct mm_struct *));
static inline void mmdrop(struct mm_struct * mm)
if (atomic_dec_and_test(&mm->mm_count))
/* 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);
/* Remove the current tasks stale references to the old mm_struct */
extern void mm_release(struct task_struct *, struct mm_struct *);
extern int copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
extern void flush_thread(void);
extern void exit_thread(void);
extern void exit_files(struct task_struct *);
extern void exit_signal(struct task_struct *);
extern void __exit_signal(struct task_struct *);
extern void exit_sighand(struct task_struct *);
extern void __exit_sighand(struct task_struct *);
extern void exit_itimers(struct signal_struct *);
extern NORET_TYPE void do_group_exit(int);
extern void daemonize(const char *, ...);
extern int allow_signal(int);
extern int disallow_signal(int);
extern task_t *child_reaper;
extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
task_t *fork_idle(int);
extern void set_task_comm(struct task_struct *tsk, char *from);
extern void get_task_comm(char *to, struct task_struct *tsk);
extern void wait_task_inactive(task_t * p);
#define wait_task_inactive(p) do { } while (0)
#define remove_parent(p) list_del_init(&(p)->sibling)
#define add_parent(p, parent) list_add_tail(&(p)->sibling,&(parent)->children)
#define REMOVE_LINKS(p) do { \
if (thread_group_leader(p)) \
list_del_init(&(p)->tasks); \
remove_parent(p); \
} while (0)
#define SET_LINKS(p) do { \
if (thread_group_leader(p)) \
list_add_tail(&(p)->tasks,&init_task.tasks); \
add_parent(p, (p)->parent); \
} while (0)
#define next_task(p) list_entry((p)->, struct task_struct, tasks)
#define prev_task(p) list_entry((p)->tasks.prev, struct task_struct, tasks)
#define for_each_process(p) \
for (p = &init_task ; (p = next_task(p)) != &init_task ; )
* 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)
extern task_t * FASTCALL(next_thread(const task_t *p));
#define thread_group_leader(p) (p->pid == p->tgid)
static inline int thread_group_empty(task_t *p)
return list_empty(&p->pids[PIDTYPE_TGID].pid_list);
#define delay_group_leader(p) \
(thread_group_leader(p) && !thread_group_empty(p))
extern void unhash_process(struct task_struct *p);
* Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring
* subscriptions and synchronises with wait4(). Also used in procfs. Also
* pins the final release of task.io_context.
* 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)
static inline void task_unlock(struct task_struct *p)
/* 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)
static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
return test_and_set_ti_thread_flag(tsk->thread_info,flag);
static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
return test_and_clear_ti_thread_flag(tsk->thread_info,flag);
static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
return test_ti_thread_flag(tsk->thread_info,flag);
static inline void set_tsk_need_resched(struct task_struct *tsk)
static inline void clear_tsk_need_resched(struct task_struct *tsk)
static inline int signal_pending(struct task_struct *p)
return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
static inline int need_resched(void)
return unlikely(test_thread_flag(TIF_NEED_RESCHED));
* 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.
extern int cond_resched(void);
extern int cond_resched_lock(spinlock_t * lock);
extern int cond_resched_softirq(void);
* Does a critical section need to be broken due to another
* task waiting?:
#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
# define need_lockbreak(lock) ((lock)->break_lock)
# define need_lockbreak(lock) 0
* Does a critical section need to be broken due to another
* task waiting or preemption being signalled:
static inline int lock_need_resched(spinlock_t *lock)
if (need_lockbreak(lock) || need_resched())
return 1;
return 0;
/* Reevaluate whether the task has signals pending delivery.
This is required every time the blocked sigset_t changes.
callers must hold sighand->siglock. */
extern FASTCALL(void recalc_sigpending_tsk(struct task_struct *t));
extern void recalc_sigpending(void);
extern void signal_wake_up(struct task_struct *t, int resume_stopped);
* Wrappers for p->thread_info->cpu access. No-op on UP.
static inline unsigned int task_cpu(const struct task_struct *p)
return p->thread_info->cpu;
static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
p->thread_info->cpu = cpu;
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 */
extern void arch_pick_mmap_layout(struct mm_struct *mm);
static inline void arch_pick_mmap_layout(struct mm_struct *mm)
mm->mmap_base = TASK_UNMAPPED_BASE;
mm->get_unmapped_area = arch_get_unmapped_area;
mm->unmap_area = arch_unmap_area;
extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
extern void normalize_rt_tasks(void);
#ifdef CONFIG_PM
* Check if a process has been frozen
static inline int frozen(struct task_struct *p)
return p->flags & PF_FROZEN;
* Check if there is a request to freeze a process
static inline int freezing(struct task_struct *p)
return p->flags & PF_FREEZE;
* Request that a process be frozen
* FIXME: SMP problem. We may not modify other process' flags!
static inline void freeze(struct task_struct *p)
p->flags |= PF_FREEZE;
* Wake up a frozen process
static inline int thaw_process(struct task_struct *p)
if (frozen(p)) {
p->flags &= ~PF_FROZEN;
return 1;
return 0;
* freezing is complete, mark process as frozen
static inline void frozen_process(struct task_struct *p)
p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
extern void refrigerator(void);
extern int freeze_processes(void);
extern void thaw_processes(void);
static inline int try_to_freeze(void)
if (freezing(current)) {
return 1;
} else
return 0;
static inline int frozen(struct task_struct *p) { return 0; }
static inline int freezing(struct task_struct *p) { return 0; }
static inline void freeze(struct task_struct *p) { BUG(); }
static inline int thaw_process(struct task_struct *p) { return 1; }
static inline void frozen_process(struct task_struct *p) { BUG(); }
static inline void refrigerator(void) {}
static inline int freeze_processes(void) { BUG(); return 0; }
static inline void thaw_processes(void) {}
static inline int try_to_freeze(void) { return 0; }
#endif /* CONFIG_PM */
#endif /* __KERNEL__ */