summaryrefslogtreecommitdiff
path: root/include/linux/sched.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/sched.h
downloadlwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r--include/linux/sched.h1273
1 files changed, 1273 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
new file mode 100644
index 000000000000..a30e91f40da6
--- /dev/null
+++ b/include/linux/sched.h
@@ -0,0 +1,1273 @@
+#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.
+ */
+#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 */
+
+#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_INTERRUPTIBLE 1
+#define TASK_UNINTERRUPTIBLE 2
+#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);
+
+#define MAX_SCHEDULE_TIMEOUT LONG_MAX
+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 */
+#define DEFAULT_MAX_MAP_COUNT 65536
+
+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 vm_area_struct *area);
+extern void arch_unmap_area_topdown(struct vm_area_struct *area);
+
+#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 vm_area_struct *area);
+ unsigned long mmap_base; /* base of mmap area */
+ unsigned long free_area_cache; /* first hole */
+ 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:1;
+ 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 */
+#ifdef CONFIG_KEYS
+ struct key *session_keyring; /* keyring inherited over fork */
+ struct key *process_keyring; /* keyring private to this process */
+#endif
+};
+
+/*
+ * 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_RT_PRIO MAX_USER_RT_PRIO
+
+#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? */
+ /* 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 ? */
+
+#ifdef CONFIG_KEYS
+ struct key *uid_keyring; /* UID specific keyring */
+ struct key *session_keyring; /* UID's default session keyring */
+#endif
+
+ /* 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;
+
+#ifdef CONFIG_SCHEDSTATS
+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;
+#endif
+
+enum idle_type
+{
+ SCHED_IDLE,
+ NOT_IDLE,
+ NEWLY_IDLE,
+ MAX_IDLE_TYPES
+};
+
+/*
+ * sched-domains (multiprocessor balancing) declarations:
+ */
+#ifdef CONFIG_SMP
+#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_WAKE_IDLE 8 /* Wake to idle CPU on task wakeup */
+#define SD_WAKE_AFFINE 16 /* Wake task to waking CPU */
+#define SD_WAKE_BALANCE 32 /* Perform balancing at task wakeup */
+#define SD_SHARE_CPUPOWER 64 /* 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 */
+ 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 */
+
+#ifdef CONFIG_SCHEDSTATS
+ /* 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;
+
+ /* sched_balance_exec() stats */
+ unsigned long sbe_attempts;
+ unsigned long sbe_pushed;
+
+ /* try_to_wake_up() stats */
+ unsigned long ttwu_wake_remote;
+ unsigned long ttwu_move_affine;
+ unsigned long ttwu_move_balance;
+#endif
+};
+
+#ifdef ARCH_HAS_SCHED_DOMAIN
+/* 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 /* ARCH_HAS_SCHED_DOMAIN */
+#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)
+
+struct group_info *groups_alloc(int gidsetsize);
+void groups_free(struct group_info *group_info);
+int set_current_groups(struct group_info *group_info);
+/* access the groups "array" with this macro */
+#define GROUP_AT(gi, i) \
+ ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK])
+
+
+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; /* Lock depth */
+
+ int prio, static_prio;
+ struct list_head run_list;
+ prio_array_t *array;
+
+ 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;
+
+#ifdef CONFIG_SCHEDSTATS
+ struct sched_info sched_info;
+#endif
+
+ 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;
+#ifdef CONFIG_KEYS
+ struct key *thread_keyring; /* keyring private to this thread */
+#endif
+ int oomkilladj; /* OOM kill score adjustment (bit shift). */
+ char comm[TASK_COMM_LEN];
+/* 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;
+/* context-switch lock */
+ spinlock_t switch_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;
+#if defined(CONFIG_BSD_PROCESS_ACCT)
+ 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 */
+#endif
+#ifdef CONFIG_NUMA
+ struct mempolicy *mempolicy;
+ short il_next;
+#endif
+#ifdef CONFIG_CPUSETS
+ struct cpuset *cpuset;
+ nodemask_t mems_allowed;
+ int cpuset_mems_generation;
+#endif
+};
+
+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)
+
+#ifdef CONFIG_SMP
+extern int set_cpus_allowed(task_t *p, cpumask_t new_mask);
+#else
+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;
+}
+#endif
+
+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 */
+#ifdef CONFIG_SMP
+extern void sched_exec(void);
+#else
+#define sched_exec() {}
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern void idle_task_exit(void);
+#else
+static inline void idle_task_exit(void) {}
+#endif
+
+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 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)];
+};
+
+#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;
+
+#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)
+{
+ atomic_inc(&u->__count);
+ 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));
+#ifdef CONFIG_SMP
+ extern void kick_process(struct task_struct *tsk);
+#else
+ static inline void kick_process(struct task_struct *tsk) { }
+#endif
+extern void FASTCALL(sched_fork(task_t * p));
+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);
+}
+
+
+#ifdef CONFIG_SECURITY
+/* code is in security.c */
+extern int capable(int cap);
+#else
+static inline int capable(int cap)
+{
+ if (cap_raised(current->cap_effective, cap)) {
+ current->flags |= PF_SUPERPRIV;
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+/*
+ * 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))
+ __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);
+/* 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_mm(struct task_struct *);
+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 reparent_to_init(void);
+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);
+
+#ifdef CONFIG_SMP
+extern void wait_task_inactive(task_t * p);
+#else
+#define wait_task_inactive(p) do { } while (0)
+#endif
+
+#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)->tasks.next, 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.
+ *
+ * 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);
+}
+
+/* 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)
+{
+ set_ti_thread_flag(tsk->thread_info,flag);
+}
+
+static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
+{
+ clear_ti_thread_flag(tsk->thread_info,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)
+{
+ 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);
+}
+
+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)
+#else
+# define need_lockbreak(lock) 0
+#endif
+
+/*
+ * 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.
+ */
+#ifdef CONFIG_SMP
+
+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;
+}
+
+#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 */
+
+#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
+extern void arch_pick_mmap_layout(struct mm_struct *mm);
+#else
+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;
+}
+#endif
+
+extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
+extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
+
+#ifdef CONFIG_MAGIC_SYSRQ
+
+extern void normalize_rt_tasks(void);
+
+#endif
+
+/* try_to_freeze
+ *
+ * Checks whether we need to enter the refrigerator
+ * and returns 1 if we did so.
+ */
+#ifdef CONFIG_PM
+extern void refrigerator(unsigned long);
+extern int freeze_processes(void);
+extern void thaw_processes(void);
+
+static inline int try_to_freeze(unsigned long refrigerator_flags)
+{
+ if (unlikely(current->flags & PF_FREEZE)) {
+ refrigerator(refrigerator_flags);
+ return 1;
+ } else
+ return 0;
+}
+#else
+static inline void refrigerator(unsigned long flag) {}
+static inline int freeze_processes(void) { BUG(); return 0; }
+static inline void thaw_processes(void) {}
+
+static inline int try_to_freeze(unsigned long refrigerator_flags)
+{
+ return 0;
+}
+#endif /* CONFIG_PM */
+#endif /* __KERNEL__ */
+
+#endif