linux/include/linux/sched.h
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   1#ifndef _LINUX_SCHED_H
   2#define _LINUX_SCHED_H
   3
   4#include <linux/auxvec.h>       /* For AT_VECTOR_SIZE */
   5
   6/*
   7 * cloning flags:
   8 */
   9#define CSIGNAL         0x000000ff      /* signal mask to be sent at exit */
  10#define CLONE_VM        0x00000100      /* set if VM shared between processes */
  11#define CLONE_FS        0x00000200      /* set if fs info shared between processes */
  12#define CLONE_FILES     0x00000400      /* set if open files shared between processes */
  13#define CLONE_SIGHAND   0x00000800      /* set if signal handlers and blocked signals shared */
  14#define CLONE_PTRACE    0x00002000      /* set if we want to let tracing continue on the child too */
  15#define CLONE_VFORK     0x00004000      /* set if the parent wants the child to wake it up on mm_release */
  16#define CLONE_PARENT    0x00008000      /* set if we want to have the same parent as the cloner */
  17#define CLONE_THREAD    0x00010000      /* Same thread group? */
  18#define CLONE_NEWNS     0x00020000      /* New namespace group? */
  19#define CLONE_SYSVSEM   0x00040000      /* share system V SEM_UNDO semantics */
  20#define CLONE_SETTLS    0x00080000      /* create a new TLS for the child */
  21#define CLONE_PARENT_SETTID     0x00100000      /* set the TID in the parent */
  22#define CLONE_CHILD_CLEARTID    0x00200000      /* clear the TID in the child */
  23#define CLONE_DETACHED          0x00400000      /* Unused, ignored */
  24#define CLONE_UNTRACED          0x00800000      /* set if the tracing process can't force CLONE_PTRACE on this clone */
  25#define CLONE_CHILD_SETTID      0x01000000      /* set the TID in the child */
  26#define CLONE_STOPPED           0x02000000      /* Start in stopped state */
  27#define CLONE_NEWUTS            0x04000000      /* New utsname group? */
  28#define CLONE_NEWIPC            0x08000000      /* New ipcs */
  29
  30/*
  31 * Scheduling policies
  32 */
  33#define SCHED_NORMAL            0
  34#define SCHED_FIFO              1
  35#define SCHED_RR                2
  36#define SCHED_BATCH             3
  37
  38#ifdef __KERNEL__
  39
  40struct sched_param {
  41        int sched_priority;
  42};
  43
  44#include <asm/param.h>  /* for HZ */
  45
  46#include <linux/capability.h>
  47#include <linux/threads.h>
  48#include <linux/kernel.h>
  49#include <linux/types.h>
  50#include <linux/timex.h>
  51#include <linux/jiffies.h>
  52#include <linux/rbtree.h>
  53#include <linux/thread_info.h>
  54#include <linux/cpumask.h>
  55#include <linux/errno.h>
  56#include <linux/nodemask.h>
  57
  58#include <asm/system.h>
  59#include <asm/semaphore.h>
  60#include <asm/page.h>
  61#include <asm/ptrace.h>
  62#include <asm/mmu.h>
  63#include <asm/cputime.h>
  64
  65#include <linux/smp.h>
  66#include <linux/sem.h>
  67#include <linux/signal.h>
  68#include <linux/securebits.h>
  69#include <linux/fs_struct.h>
  70#include <linux/compiler.h>
  71#include <linux/completion.h>
  72#include <linux/pid.h>
  73#include <linux/percpu.h>
  74#include <linux/topology.h>
  75#include <linux/seccomp.h>
  76#include <linux/rcupdate.h>
  77#include <linux/futex.h>
  78#include <linux/rtmutex.h>
  79
  80#include <linux/time.h>
  81#include <linux/param.h>
  82#include <linux/resource.h>
  83#include <linux/timer.h>
  84#include <linux/hrtimer.h>
  85#include <linux/task_io_accounting.h>
  86
  87#include <asm/processor.h>
  88
  89struct exec_domain;
  90struct futex_pi_state;
  91struct bio;
  92
  93/*
  94 * List of flags we want to share for kernel threads,
  95 * if only because they are not used by them anyway.
  96 */
  97#define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
  98
  99/*
 100 * These are the constant used to fake the fixed-point load-average
 101 * counting. Some notes:
 102 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 103 *    a load-average precision of 10 bits integer + 11 bits fractional
 104 *  - if you want to count load-averages more often, you need more
 105 *    precision, or rounding will get you. With 2-second counting freq,
 106 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 107 *    11 bit fractions.
 108 */
 109extern unsigned long avenrun[];         /* Load averages */
 110
 111#define FSHIFT          11              /* nr of bits of precision */
 112#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 113#define LOAD_FREQ       (5*HZ)          /* 5 sec intervals */
 114#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 115#define EXP_5           2014            /* 1/exp(5sec/5min) */
 116#define EXP_15          2037            /* 1/exp(5sec/15min) */
 117
 118#define CALC_LOAD(load,exp,n) \
 119        load *= exp; \
 120        load += n*(FIXED_1-exp); \
 121        load >>= FSHIFT;
 122
 123extern unsigned long total_forks;
 124extern int nr_threads;
 125DECLARE_PER_CPU(unsigned long, process_counts);
 126extern int nr_processes(void);
 127extern unsigned long nr_running(void);
 128extern unsigned long nr_uninterruptible(void);
 129extern unsigned long nr_active(void);
 130extern unsigned long nr_iowait(void);
 131extern unsigned long weighted_cpuload(const int cpu);
 132
 133
 134/*
 135 * Task state bitmask. NOTE! These bits are also
 136 * encoded in fs/proc/array.c: get_task_state().
 137 *
 138 * We have two separate sets of flags: task->state
 139 * is about runnability, while task->exit_state are
 140 * about the task exiting. Confusing, but this way
 141 * modifying one set can't modify the other one by
 142 * mistake.
 143 */
 144#define TASK_RUNNING            0
 145#define TASK_INTERRUPTIBLE      1
 146#define TASK_UNINTERRUPTIBLE    2
 147#define TASK_STOPPED            4
 148#define TASK_TRACED             8
 149/* in tsk->exit_state */
 150#define EXIT_ZOMBIE             16
 151#define EXIT_DEAD               32
 152/* in tsk->state again */
 153#define TASK_NONINTERACTIVE     64
 154#define TASK_DEAD               128
 155
 156#define __set_task_state(tsk, state_value)              \
 157        do { (tsk)->state = (state_value); } while (0)
 158#define set_task_state(tsk, state_value)                \
 159        set_mb((tsk)->state, (state_value))
 160
 161/*
 162 * set_current_state() includes a barrier so that the write of current->state
 163 * is correctly serialised wrt the caller's subsequent test of whether to
 164 * actually sleep:
 165 *
 166 *      set_current_state(TASK_UNINTERRUPTIBLE);
 167 *      if (do_i_need_to_sleep())
 168 *              schedule();
 169 *
 170 * If the caller does not need such serialisation then use __set_current_state()
 171 */
 172#define __set_current_state(state_value)                        \
 173        do { current->state = (state_value); } while (0)
 174#define set_current_state(state_value)          \
 175        set_mb(current->state, (state_value))
 176
 177/* Task command name length */
 178#define TASK_COMM_LEN 16
 179
 180#include <linux/spinlock.h>
 181
 182/*
 183 * This serializes "schedule()" and also protects
 184 * the run-queue from deletions/modifications (but
 185 * _adding_ to the beginning of the run-queue has
 186 * a separate lock).
 187 */
 188extern rwlock_t tasklist_lock;
 189extern spinlock_t mmlist_lock;
 190
 191struct task_struct;
 192
 193extern void sched_init(void);
 194extern void sched_init_smp(void);
 195extern void init_idle(struct task_struct *idle, int cpu);
 196
 197extern cpumask_t nohz_cpu_mask;
 198#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
 199extern int select_nohz_load_balancer(int cpu);
 200#else
 201static inline int select_nohz_load_balancer(int cpu)
 202{
 203        return 0;
 204}
 205#endif
 206
 207/*
 208 * Only dump TASK_* tasks. (0 for all tasks)
 209 */
 210extern void show_state_filter(unsigned long state_filter);
 211
 212static inline void show_state(void)
 213{
 214        show_state_filter(0);
 215}
 216
 217extern void show_regs(struct pt_regs *);
 218
 219/*
 220 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 221 * task), SP is the stack pointer of the first frame that should be shown in the back
 222 * trace (or NULL if the entire call-chain of the task should be shown).
 223 */
 224extern void show_stack(struct task_struct *task, unsigned long *sp);
 225
 226void io_schedule(void);
 227long io_schedule_timeout(long timeout);
 228
 229extern void cpu_init (void);
 230extern void trap_init(void);
 231extern void update_process_times(int user);
 232extern void scheduler_tick(void);
 233
 234#ifdef CONFIG_DETECT_SOFTLOCKUP
 235extern void softlockup_tick(void);
 236extern void spawn_softlockup_task(void);
 237extern void touch_softlockup_watchdog(void);
 238extern void touch_all_softlockup_watchdogs(void);
 239#else
 240static inline void softlockup_tick(void)
 241{
 242}
 243static inline void spawn_softlockup_task(void)
 244{
 245}
 246static inline void touch_softlockup_watchdog(void)
 247{
 248}
 249static inline void touch_all_softlockup_watchdogs(void)
 250{
 251}
 252#endif
 253
 254
 255/* Attach to any functions which should be ignored in wchan output. */
 256#define __sched         __attribute__((__section__(".sched.text")))
 257/* Is this address in the __sched functions? */
 258extern int in_sched_functions(unsigned long addr);
 259
 260#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 261extern signed long FASTCALL(schedule_timeout(signed long timeout));
 262extern signed long schedule_timeout_interruptible(signed long timeout);
 263extern signed long schedule_timeout_uninterruptible(signed long timeout);
 264asmlinkage void schedule(void);
 265
 266struct nsproxy;
 267
 268/* Maximum number of active map areas.. This is a random (large) number */
 269#define DEFAULT_MAX_MAP_COUNT   65536
 270
 271extern int sysctl_max_map_count;
 272
 273#include <linux/aio.h>
 274
 275extern unsigned long
 276arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 277                       unsigned long, unsigned long);
 278extern unsigned long
 279arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 280                          unsigned long len, unsigned long pgoff,
 281                          unsigned long flags);
 282extern void arch_unmap_area(struct mm_struct *, unsigned long);
 283extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 284
 285#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
 286/*
 287 * The mm counters are not protected by its page_table_lock,
 288 * so must be incremented atomically.
 289 */
 290#define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
 291#define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
 292#define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
 293#define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
 294#define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
 295typedef atomic_long_t mm_counter_t;
 296
 297#else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
 298/*
 299 * The mm counters are protected by its page_table_lock,
 300 * so can be incremented directly.
 301 */
 302#define set_mm_counter(mm, member, value) (mm)->_##member = (value)
 303#define get_mm_counter(mm, member) ((mm)->_##member)
 304#define add_mm_counter(mm, member, value) (mm)->_##member += (value)
 305#define inc_mm_counter(mm, member) (mm)->_##member++
 306#define dec_mm_counter(mm, member) (mm)->_##member--
 307typedef unsigned long mm_counter_t;
 308
 309#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
 310
 311#define get_mm_rss(mm)                                  \
 312        (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
 313#define update_hiwater_rss(mm)  do {                    \
 314        unsigned long _rss = get_mm_rss(mm);            \
 315        if ((mm)->hiwater_rss < _rss)                   \
 316                (mm)->hiwater_rss = _rss;               \
 317} while (0)
 318#define update_hiwater_vm(mm)   do {                    \
 319        if ((mm)->hiwater_vm < (mm)->total_vm)          \
 320                (mm)->hiwater_vm = (mm)->total_vm;      \
 321} while (0)
 322
 323struct mm_struct {
 324        struct vm_area_struct * mmap;           /* list of VMAs */
 325        struct rb_root mm_rb;
 326        struct vm_area_struct * mmap_cache;     /* last find_vma result */
 327        unsigned long (*get_unmapped_area) (struct file *filp,
 328                                unsigned long addr, unsigned long len,
 329                                unsigned long pgoff, unsigned long flags);
 330        void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
 331        unsigned long mmap_base;                /* base of mmap area */
 332        unsigned long task_size;                /* size of task vm space */
 333        unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
 334        unsigned long free_area_cache;          /* first hole of size cached_hole_size or larger */
 335        pgd_t * pgd;
 336        atomic_t mm_users;                      /* How many users with user space? */
 337        atomic_t mm_count;                      /* How many references to "struct mm_struct" (users count as 1) */
 338        int map_count;                          /* number of VMAs */
 339        struct rw_semaphore mmap_sem;
 340        spinlock_t page_table_lock;             /* Protects page tables and some counters */
 341
 342        struct list_head mmlist;                /* List of maybe swapped mm's.  These are globally strung
 343                                                 * together off init_mm.mmlist, and are protected
 344                                                 * by mmlist_lock
 345                                                 */
 346
 347        /* Special counters, in some configurations protected by the
 348         * page_table_lock, in other configurations by being atomic.
 349         */
 350        mm_counter_t _file_rss;
 351        mm_counter_t _anon_rss;
 352
 353        unsigned long hiwater_rss;      /* High-watermark of RSS usage */
 354        unsigned long hiwater_vm;       /* High-water virtual memory usage */
 355
 356        unsigned long total_vm, locked_vm, shared_vm, exec_vm;
 357        unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
 358        unsigned long start_code, end_code, start_data, end_data;
 359        unsigned long start_brk, brk, start_stack;
 360        unsigned long arg_start, arg_end, env_start, env_end;
 361
 362        unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
 363
 364        cpumask_t cpu_vm_mask;
 365
 366        /* Architecture-specific MM context */
 367        mm_context_t context;
 368
 369        /* Swap token stuff */
 370        /*
 371         * Last value of global fault stamp as seen by this process.
 372         * In other words, this value gives an indication of how long
 373         * it has been since this task got the token.
 374         * Look at mm/thrash.c
 375         */
 376        unsigned int faultstamp;
 377        unsigned int token_priority;
 378        unsigned int last_interval;
 379
 380        unsigned char dumpable:2;
 381
 382        /* coredumping support */
 383        int core_waiters;
 384        struct completion *core_startup_done, core_done;
 385
 386        /* aio bits */
 387        rwlock_t                ioctx_list_lock;
 388        struct kioctx           *ioctx_list;
 389};
 390
 391struct sighand_struct {
 392        atomic_t                count;
 393        struct k_sigaction      action[_NSIG];
 394        spinlock_t              siglock;
 395        struct list_head        signalfd_list;
 396};
 397
 398struct pacct_struct {
 399        int                     ac_flag;
 400        long                    ac_exitcode;
 401        unsigned long           ac_mem;
 402        cputime_t               ac_utime, ac_stime;
 403        unsigned long           ac_minflt, ac_majflt;
 404};
 405
 406/*
 407 * NOTE! "signal_struct" does not have it's own
 408 * locking, because a shared signal_struct always
 409 * implies a shared sighand_struct, so locking
 410 * sighand_struct is always a proper superset of
 411 * the locking of signal_struct.
 412 */
 413struct signal_struct {
 414        atomic_t                count;
 415        atomic_t                live;
 416
 417        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 418
 419        /* current thread group signal load-balancing target: */
 420        struct task_struct      *curr_target;
 421
 422        /* shared signal handling: */
 423        struct sigpending       shared_pending;
 424
 425        /* thread group exit support */
 426        int                     group_exit_code;
 427        /* overloaded:
 428         * - notify group_exit_task when ->count is equal to notify_count
 429         * - everyone except group_exit_task is stopped during signal delivery
 430         *   of fatal signals, group_exit_task processes the signal.
 431         */
 432        struct task_struct      *group_exit_task;
 433        int                     notify_count;
 434
 435        /* thread group stop support, overloads group_exit_code too */
 436        int                     group_stop_count;
 437        unsigned int            flags; /* see SIGNAL_* flags below */
 438
 439        /* POSIX.1b Interval Timers */
 440        struct list_head posix_timers;
 441
 442        /* ITIMER_REAL timer for the process */
 443        struct hrtimer real_timer;
 444        struct task_struct *tsk;
 445        ktime_t it_real_incr;
 446
 447        /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
 448        cputime_t it_prof_expires, it_virt_expires;
 449        cputime_t it_prof_incr, it_virt_incr;
 450
 451        /* job control IDs */
 452        pid_t pgrp;
 453        struct pid *tty_old_pgrp;
 454
 455        union {
 456                pid_t session __deprecated;
 457                pid_t __session;
 458        };
 459
 460        /* boolean value for session group leader */
 461        int leader;
 462
 463        struct tty_struct *tty; /* NULL if no tty */
 464
 465        /*
 466         * Cumulative resource counters for dead threads in the group,
 467         * and for reaped dead child processes forked by this group.
 468         * Live threads maintain their own counters and add to these
 469         * in __exit_signal, except for the group leader.
 470         */
 471        cputime_t utime, stime, cutime, cstime;
 472        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 473        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 474        unsigned long inblock, oublock, cinblock, coublock;
 475
 476        /*
 477         * Cumulative ns of scheduled CPU time for dead threads in the
 478         * group, not including a zombie group leader.  (This only differs
 479         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 480         * other than jiffies.)
 481         */
 482        unsigned long long sched_time;
 483
 484        /*
 485         * We don't bother to synchronize most readers of this at all,
 486         * because there is no reader checking a limit that actually needs
 487         * to get both rlim_cur and rlim_max atomically, and either one
 488         * alone is a single word that can safely be read normally.
 489         * getrlimit/setrlimit use task_lock(current->group_leader) to
 490         * protect this instead of the siglock, because they really
 491         * have no need to disable irqs.
 492         */
 493        struct rlimit rlim[RLIM_NLIMITS];
 494
 495        struct list_head cpu_timers[3];
 496
 497        /* keep the process-shared keyrings here so that they do the right
 498         * thing in threads created with CLONE_THREAD */
 499#ifdef CONFIG_KEYS
 500        struct key *session_keyring;    /* keyring inherited over fork */
 501        struct key *process_keyring;    /* keyring private to this process */
 502#endif
 503#ifdef CONFIG_BSD_PROCESS_ACCT
 504        struct pacct_struct pacct;      /* per-process accounting information */
 505#endif
 506#ifdef CONFIG_TASKSTATS
 507        struct taskstats *stats;
 508#endif
 509};
 510
 511/* Context switch must be unlocked if interrupts are to be enabled */
 512#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
 513# define __ARCH_WANT_UNLOCKED_CTXSW
 514#endif
 515
 516/*
 517 * Bits in flags field of signal_struct.
 518 */
 519#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 520#define SIGNAL_STOP_DEQUEUED    0x00000002 /* stop signal dequeued */
 521#define SIGNAL_STOP_CONTINUED   0x00000004 /* SIGCONT since WCONTINUED reap */
 522#define SIGNAL_GROUP_EXIT       0x00000008 /* group exit in progress */
 523
 524
 525/*
 526 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
 527 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
 528 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
 529 * values are inverted: lower p->prio value means higher priority.
 530 *
 531 * The MAX_USER_RT_PRIO value allows the actual maximum
 532 * RT priority to be separate from the value exported to
 533 * user-space.  This allows kernel threads to set their
 534 * priority to a value higher than any user task. Note:
 535 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
 536 */
 537
 538#define MAX_USER_RT_PRIO        100
 539#define MAX_RT_PRIO             MAX_USER_RT_PRIO
 540
 541#define MAX_PRIO                (MAX_RT_PRIO + 40)
 542
 543#define rt_prio(prio)           unlikely((prio) < MAX_RT_PRIO)
 544#define rt_task(p)              rt_prio((p)->prio)
 545#define batch_task(p)           (unlikely((p)->policy == SCHED_BATCH))
 546#define is_rt_policy(p)         ((p) != SCHED_NORMAL && (p) != SCHED_BATCH)
 547#define has_rt_policy(p)        unlikely(is_rt_policy((p)->policy))
 548
 549/*
 550 * Some day this will be a full-fledged user tracking system..
 551 */
 552struct user_struct {
 553        atomic_t __count;       /* reference count */
 554        atomic_t processes;     /* How many processes does this user have? */
 555        atomic_t files;         /* How many open files does this user have? */
 556        atomic_t sigpending;    /* How many pending signals does this user have? */
 557#ifdef CONFIG_INOTIFY_USER
 558        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 559        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 560#endif
 561        /* protected by mq_lock */
 562        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 563        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 564
 565#ifdef CONFIG_KEYS
 566        struct key *uid_keyring;        /* UID specific keyring */
 567        struct key *session_keyring;    /* UID's default session keyring */
 568#endif
 569
 570        /* Hash table maintenance information */
 571        struct list_head uidhash_list;
 572        uid_t uid;
 573};
 574
 575extern struct user_struct *find_user(uid_t);
 576
 577extern struct user_struct root_user;
 578#define INIT_USER (&root_user)
 579
 580struct backing_dev_info;
 581struct reclaim_state;
 582
 583#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 584struct sched_info {
 585        /* cumulative counters */
 586        unsigned long   cpu_time,       /* time spent on the cpu */
 587                        run_delay,      /* time spent waiting on a runqueue */
 588                        pcnt;           /* # of timeslices run on this cpu */
 589
 590        /* timestamps */
 591        unsigned long   last_arrival,   /* when we last ran on a cpu */
 592                        last_queued;    /* when we were last queued to run */
 593};
 594#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
 595
 596#ifdef CONFIG_SCHEDSTATS
 597extern const struct file_operations proc_schedstat_operations;
 598#endif /* CONFIG_SCHEDSTATS */
 599
 600#ifdef CONFIG_TASK_DELAY_ACCT
 601struct task_delay_info {
 602        spinlock_t      lock;
 603        unsigned int    flags;  /* Private per-task flags */
 604
 605        /* For each stat XXX, add following, aligned appropriately
 606         *
 607         * struct timespec XXX_start, XXX_end;
 608         * u64 XXX_delay;
 609         * u32 XXX_count;
 610         *
 611         * Atomicity of updates to XXX_delay, XXX_count protected by
 612         * single lock above (split into XXX_lock if contention is an issue).
 613         */
 614
 615        /*
 616         * XXX_count is incremented on every XXX operation, the delay
 617         * associated with the operation is added to XXX_delay.
 618         * XXX_delay contains the accumulated delay time in nanoseconds.
 619         */
 620        struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
 621        u64 blkio_delay;        /* wait for sync block io completion */
 622        u64 swapin_delay;       /* wait for swapin block io completion */
 623        u32 blkio_count;        /* total count of the number of sync block */
 624                                /* io operations performed */
 625        u32 swapin_count;       /* total count of the number of swapin block */
 626                                /* io operations performed */
 627};
 628#endif  /* CONFIG_TASK_DELAY_ACCT */
 629
 630static inline int sched_info_on(void)
 631{
 632#ifdef CONFIG_SCHEDSTATS
 633        return 1;
 634#elif defined(CONFIG_TASK_DELAY_ACCT)
 635        extern int delayacct_on;
 636        return delayacct_on;
 637#else
 638        return 0;
 639#endif
 640}
 641
 642enum idle_type
 643{
 644        SCHED_IDLE,
 645        NOT_IDLE,
 646        NEWLY_IDLE,
 647        MAX_IDLE_TYPES
 648};
 649
 650/*
 651 * sched-domains (multiprocessor balancing) declarations:
 652 */
 653#define SCHED_LOAD_SCALE        128UL   /* increase resolution of load */
 654
 655#ifdef CONFIG_SMP
 656#define SD_LOAD_BALANCE         1       /* Do load balancing on this domain. */
 657#define SD_BALANCE_NEWIDLE      2       /* Balance when about to become idle */
 658#define SD_BALANCE_EXEC         4       /* Balance on exec */
 659#define SD_BALANCE_FORK         8       /* Balance on fork, clone */
 660#define SD_WAKE_IDLE            16      /* Wake to idle CPU on task wakeup */
 661#define SD_WAKE_AFFINE          32      /* Wake task to waking CPU */
 662#define SD_WAKE_BALANCE         64      /* Perform balancing at task wakeup */
 663#define SD_SHARE_CPUPOWER       128     /* Domain members share cpu power */
 664#define SD_POWERSAVINGS_BALANCE 256     /* Balance for power savings */
 665#define SD_SHARE_PKG_RESOURCES  512     /* Domain members share cpu pkg resources */
 666#define SD_SERIALIZE            1024    /* Only a single load balancing instance */
 667
 668#define BALANCE_FOR_MC_POWER    \
 669        (sched_smt_power_savings ? SD_POWERSAVINGS_BALANCE : 0)
 670
 671#define BALANCE_FOR_PKG_POWER   \
 672        ((sched_mc_power_savings || sched_smt_power_savings) ?  \
 673         SD_POWERSAVINGS_BALANCE : 0)
 674
 675#define test_sd_parent(sd, flag)        ((sd->parent &&         \
 676                                         (sd->parent->flags & flag)) ? 1 : 0)
 677
 678
 679struct sched_group {
 680        struct sched_group *next;       /* Must be a circular list */
 681        cpumask_t cpumask;
 682
 683        /*
 684         * CPU power of this group, SCHED_LOAD_SCALE being max power for a
 685         * single CPU. This is read only (except for setup, hotplug CPU).
 686         * Note : Never change cpu_power without recompute its reciprocal
 687         */
 688        unsigned int __cpu_power;
 689        /*
 690         * reciprocal value of cpu_power to avoid expensive divides
 691         * (see include/linux/reciprocal_div.h)
 692         */
 693        u32 reciprocal_cpu_power;
 694};
 695
 696struct sched_domain {
 697        /* These fields must be setup */
 698        struct sched_domain *parent;    /* top domain must be null terminated */
 699        struct sched_domain *child;     /* bottom domain must be null terminated */
 700        struct sched_group *groups;     /* the balancing groups of the domain */
 701        cpumask_t span;                 /* span of all CPUs in this domain */
 702        unsigned long min_interval;     /* Minimum balance interval ms */
 703        unsigned long max_interval;     /* Maximum balance interval ms */
 704        unsigned int busy_factor;       /* less balancing by factor if busy */
 705        unsigned int imbalance_pct;     /* No balance until over watermark */
 706        unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
 707        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
 708        unsigned int busy_idx;
 709        unsigned int idle_idx;
 710        unsigned int newidle_idx;
 711        unsigned int wake_idx;
 712        unsigned int forkexec_idx;
 713        int flags;                      /* See SD_* */
 714
 715        /* Runtime fields. */
 716        unsigned long last_balance;     /* init to jiffies. units in jiffies */
 717        unsigned int balance_interval;  /* initialise to 1. units in ms. */
 718        unsigned int nr_balance_failed; /* initialise to 0 */
 719
 720#ifdef CONFIG_SCHEDSTATS
 721        /* load_balance() stats */
 722        unsigned long lb_cnt[MAX_IDLE_TYPES];
 723        unsigned long lb_failed[MAX_IDLE_TYPES];
 724        unsigned long lb_balanced[MAX_IDLE_TYPES];
 725        unsigned long lb_imbalance[MAX_IDLE_TYPES];
 726        unsigned long lb_gained[MAX_IDLE_TYPES];
 727        unsigned long lb_hot_gained[MAX_IDLE_TYPES];
 728        unsigned long lb_nobusyg[MAX_IDLE_TYPES];
 729        unsigned long lb_nobusyq[MAX_IDLE_TYPES];
 730
 731        /* Active load balancing */
 732        unsigned long alb_cnt;
 733        unsigned long alb_failed;
 734        unsigned long alb_pushed;
 735
 736        /* SD_BALANCE_EXEC stats */
 737        unsigned long sbe_cnt;
 738        unsigned long sbe_balanced;
 739        unsigned long sbe_pushed;
 740
 741        /* SD_BALANCE_FORK stats */
 742        unsigned long sbf_cnt;
 743        unsigned long sbf_balanced;
 744        unsigned long sbf_pushed;
 745
 746        /* try_to_wake_up() stats */
 747        unsigned long ttwu_wake_remote;
 748        unsigned long ttwu_move_affine;
 749        unsigned long ttwu_move_balance;
 750#endif
 751};
 752
 753extern int partition_sched_domains(cpumask_t *partition1,
 754                                    cpumask_t *partition2);
 755
 756/*
 757 * Maximum cache size the migration-costs auto-tuning code will
 758 * search from:
 759 */
 760extern unsigned int max_cache_size;
 761
 762#endif  /* CONFIG_SMP */
 763
 764
 765struct io_context;                      /* See blkdev.h */
 766struct cpuset;
 767
 768#define NGROUPS_SMALL           32
 769#define NGROUPS_PER_BLOCK       ((int)(PAGE_SIZE / sizeof(gid_t)))
 770struct group_info {
 771        int ngroups;
 772        atomic_t usage;
 773        gid_t small_block[NGROUPS_SMALL];
 774        int nblocks;
 775        gid_t *blocks[0];
 776};
 777
 778/*
 779 * get_group_info() must be called with the owning task locked (via task_lock())
 780 * when task != current.  The reason being that the vast majority of callers are
 781 * looking at current->group_info, which can not be changed except by the
 782 * current task.  Changing current->group_info requires the task lock, too.
 783 */
 784#define get_group_info(group_info) do { \
 785        atomic_inc(&(group_info)->usage); \
 786} while (0)
 787
 788#define put_group_info(group_info) do { \
 789        if (atomic_dec_and_test(&(group_info)->usage)) \
 790                groups_free(group_info); \
 791} while (0)
 792
 793extern struct group_info *groups_alloc(int gidsetsize);
 794extern void groups_free(struct group_info *group_info);
 795extern int set_current_groups(struct group_info *group_info);
 796extern int groups_search(struct group_info *group_info, gid_t grp);
 797/* access the groups "array" with this macro */
 798#define GROUP_AT(gi, i) \
 799    ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK])
 800
 801#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
 802extern void prefetch_stack(struct task_struct *t);
 803#else
 804static inline void prefetch_stack(struct task_struct *t) { }
 805#endif
 806
 807struct audit_context;           /* See audit.c */
 808struct mempolicy;
 809struct pipe_inode_info;
 810struct uts_namespace;
 811
 812enum sleep_type {
 813        SLEEP_NORMAL,
 814        SLEEP_NONINTERACTIVE,
 815        SLEEP_INTERACTIVE,
 816        SLEEP_INTERRUPTED,
 817};
 818
 819struct prio_array;
 820
 821struct task_struct {
 822        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
 823        void *stack;
 824        atomic_t usage;
 825        unsigned int flags;     /* per process flags, defined below */
 826        unsigned int ptrace;
 827
 828        int lock_depth;         /* BKL lock depth */
 829
 830#ifdef CONFIG_SMP
 831#ifdef __ARCH_WANT_UNLOCKED_CTXSW
 832        int oncpu;
 833#endif
 834#endif
 835        int load_weight;        /* for niceness load balancing purposes */
 836        int prio, static_prio, normal_prio;
 837        struct list_head run_list;
 838        struct prio_array *array;
 839
 840        unsigned short ioprio;
 841#ifdef CONFIG_BLK_DEV_IO_TRACE
 842        unsigned int btrace_seq;
 843#endif
 844        unsigned long sleep_avg;
 845        unsigned long long timestamp, last_ran;
 846        unsigned long long sched_time; /* sched_clock time spent running */
 847        enum sleep_type sleep_type;
 848
 849        unsigned int policy;
 850        cpumask_t cpus_allowed;
 851        unsigned int time_slice, first_time_slice;
 852
 853#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 854        struct sched_info sched_info;
 855#endif
 856
 857        struct list_head tasks;
 858        /*
 859         * ptrace_list/ptrace_children forms the list of my children
 860         * that were stolen by a ptracer.
 861         */
 862        struct list_head ptrace_children;
 863        struct list_head ptrace_list;
 864
 865        struct mm_struct *mm, *active_mm;
 866
 867/* task state */
 868        struct linux_binfmt *binfmt;
 869        int exit_state;
 870        int exit_code, exit_signal;
 871        int pdeath_signal;  /*  The signal sent when the parent dies  */
 872        /* ??? */
 873        unsigned int personality;
 874        unsigned did_exec:1;
 875        pid_t pid;
 876        pid_t tgid;
 877
 878#ifdef CONFIG_CC_STACKPROTECTOR
 879        /* Canary value for the -fstack-protector gcc feature */
 880        unsigned long stack_canary;
 881#endif
 882        /* 
 883         * pointers to (original) parent process, youngest child, younger sibling,
 884         * older sibling, respectively.  (p->father can be replaced with 
 885         * p->parent->pid)
 886         */
 887        struct task_struct *real_parent; /* real parent process (when being debugged) */
 888        struct task_struct *parent;     /* parent process */
 889        /*
 890         * children/sibling forms the list of my children plus the
 891         * tasks I'm ptracing.
 892         */
 893        struct list_head children;      /* list of my children */
 894        struct list_head sibling;       /* linkage in my parent's children list */
 895        struct task_struct *group_leader;       /* threadgroup leader */
 896
 897        /* PID/PID hash table linkage. */
 898        struct pid_link pids[PIDTYPE_MAX];
 899        struct list_head thread_group;
 900
 901        struct completion *vfork_done;          /* for vfork() */
 902        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
 903        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
 904
 905        unsigned int rt_priority;
 906        cputime_t utime, stime;
 907        unsigned long nvcsw, nivcsw; /* context switch counts */
 908        struct timespec start_time;
 909/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
 910        unsigned long min_flt, maj_flt;
 911
 912        cputime_t it_prof_expires, it_virt_expires;
 913        unsigned long long it_sched_expires;
 914        struct list_head cpu_timers[3];
 915
 916/* process credentials */
 917        uid_t uid,euid,suid,fsuid;
 918        gid_t gid,egid,sgid,fsgid;
 919        struct group_info *group_info;
 920        kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
 921        unsigned keep_capabilities:1;
 922        struct user_struct *user;
 923#ifdef CONFIG_KEYS
 924        struct key *request_key_auth;   /* assumed request_key authority */
 925        struct key *thread_keyring;     /* keyring private to this thread */
 926        unsigned char jit_keyring;      /* default keyring to attach requested keys to */
 927#endif
 928        /*
 929         * fpu_counter contains the number of consecutive context switches
 930         * that the FPU is used. If this is over a threshold, the lazy fpu
 931         * saving becomes unlazy to save the trap. This is an unsigned char
 932         * so that after 256 times the counter wraps and the behavior turns
 933         * lazy again; this to deal with bursty apps that only use FPU for
 934         * a short time
 935         */
 936        unsigned char fpu_counter;
 937        int oomkilladj; /* OOM kill score adjustment (bit shift). */
 938        char comm[TASK_COMM_LEN]; /* executable name excluding path
 939                                     - access with [gs]et_task_comm (which lock
 940                                       it with task_lock())
 941                                     - initialized normally by flush_old_exec */
 942/* file system info */
 943        int link_count, total_link_count;
 944#ifdef CONFIG_SYSVIPC
 945/* ipc stuff */
 946        struct sysv_sem sysvsem;
 947#endif
 948/* CPU-specific state of this task */
 949        struct thread_struct thread;
 950/* filesystem information */
 951        struct fs_struct *fs;
 952/* open file information */
 953        struct files_struct *files;
 954/* namespaces */
 955        struct nsproxy *nsproxy;
 956/* signal handlers */
 957        struct signal_struct *signal;
 958        struct sighand_struct *sighand;
 959
 960        sigset_t blocked, real_blocked;
 961        sigset_t saved_sigmask;         /* To be restored with TIF_RESTORE_SIGMASK */
 962        struct sigpending pending;
 963
 964        unsigned long sas_ss_sp;
 965        size_t sas_ss_size;
 966        int (*notifier)(void *priv);
 967        void *notifier_data;
 968        sigset_t *notifier_mask;
 969        
 970        void *security;
 971        struct audit_context *audit_context;
 972        seccomp_t seccomp;
 973
 974/* Thread group tracking */
 975        u32 parent_exec_id;
 976        u32 self_exec_id;
 977/* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
 978        spinlock_t alloc_lock;
 979
 980        /* Protection of the PI data structures: */
 981        spinlock_t pi_lock;
 982
 983#ifdef CONFIG_RT_MUTEXES
 984        /* PI waiters blocked on a rt_mutex held by this task */
 985        struct plist_head pi_waiters;
 986        /* Deadlock detection and priority inheritance handling */
 987        struct rt_mutex_waiter *pi_blocked_on;
 988#endif
 989
 990#ifdef CONFIG_DEBUG_MUTEXES
 991        /* mutex deadlock detection */
 992        struct mutex_waiter *blocked_on;
 993#endif
 994#ifdef CONFIG_TRACE_IRQFLAGS
 995        unsigned int irq_events;
 996        int hardirqs_enabled;
 997        unsigned long hardirq_enable_ip;
 998        unsigned int hardirq_enable_event;
 999        unsigned long hardirq_disable_ip;
1000        unsigned int hardirq_disable_event;
1001        int softirqs_enabled;
1002        unsigned long softirq_disable_ip;
1003        unsigned int softirq_disable_event;
1004        unsigned long softirq_enable_ip;
1005        unsigned int softirq_enable_event;
1006        int hardirq_context;
1007        int softirq_context;
1008#endif
1009#ifdef CONFIG_LOCKDEP
1010# define MAX_LOCK_DEPTH 30UL
1011        u64 curr_chain_key;
1012        int lockdep_depth;
1013        struct held_lock held_locks[MAX_LOCK_DEPTH];
1014        unsigned int lockdep_recursion;
1015#endif
1016
1017/* journalling filesystem info */
1018        void *journal_info;
1019
1020/* stacked block device info */
1021        struct bio *bio_list, **bio_tail;
1022
1023/* VM state */
1024        struct reclaim_state *reclaim_state;
1025
1026        struct backing_dev_info *backing_dev_info;
1027
1028        struct io_context *io_context;
1029
1030        unsigned long ptrace_message;
1031        siginfo_t *last_siginfo; /* For ptrace use.  */
1032/*
1033 * current io wait handle: wait queue entry to use for io waits
1034 * If this thread is processing aio, this points at the waitqueue
1035 * inside the currently handled kiocb. It may be NULL (i.e. default
1036 * to a stack based synchronous wait) if its doing sync IO.
1037 */
1038        wait_queue_t *io_wait;
1039#ifdef CONFIG_TASK_XACCT
1040/* i/o counters(bytes read/written, #syscalls */
1041        u64 rchar, wchar, syscr, syscw;
1042#endif
1043        struct task_io_accounting ioac;
1044#if defined(CONFIG_TASK_XACCT)
1045        u64 acct_rss_mem1;      /* accumulated rss usage */
1046        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1047        cputime_t acct_stimexpd;/* stime since last update */
1048#endif
1049#ifdef CONFIG_NUMA
1050        struct mempolicy *mempolicy;
1051        short il_next;
1052#endif
1053#ifdef CONFIG_CPUSETS
1054        struct cpuset *cpuset;
1055        nodemask_t mems_allowed;
1056        int cpuset_mems_generation;
1057        int cpuset_mem_spread_rotor;
1058#endif
1059        struct robust_list_head __user *robust_list;
1060#ifdef CONFIG_COMPAT
1061        struct compat_robust_list_head __user *compat_robust_list;
1062#endif
1063        struct list_head pi_state_list;
1064        struct futex_pi_state *pi_state_cache;
1065
1066        atomic_t fs_excl;       /* holding fs exclusive resources */
1067        struct rcu_head rcu;
1068
1069        /*
1070         * cache last used pipe for splice
1071         */
1072        struct pipe_inode_info *splice_pipe;
1073#ifdef  CONFIG_TASK_DELAY_ACCT
1074        struct task_delay_info *delays;
1075#endif
1076#ifdef CONFIG_FAULT_INJECTION
1077        int make_it_fail;
1078#endif
1079};
1080
1081static inline pid_t process_group(struct task_struct *tsk)
1082{
1083        return tsk->signal->pgrp;
1084}
1085
1086static inline pid_t signal_session(struct signal_struct *sig)
1087{
1088        return sig->__session;
1089}
1090
1091static inline pid_t process_session(struct task_struct *tsk)
1092{
1093        return signal_session(tsk->signal);
1094}
1095
1096static inline void set_signal_session(struct signal_struct *sig, pid_t session)
1097{
1098        sig->__session = session;
1099}
1100
1101static inline struct pid *task_pid(struct task_struct *task)
1102{
1103        return task->pids[PIDTYPE_PID].pid;
1104}
1105
1106static inline struct pid *task_tgid(struct task_struct *task)
1107{
1108        return task->group_leader->pids[PIDTYPE_PID].pid;
1109}
1110
1111static inline struct pid *task_pgrp(struct task_struct *task)
1112{
1113        return task->group_leader->pids[PIDTYPE_PGID].pid;
1114}
1115
1116static inline struct pid *task_session(struct task_struct *task)
1117{
1118        return task->group_leader->pids[PIDTYPE_SID].pid;
1119}
1120
1121/**
1122 * pid_alive - check that a task structure is not stale
1123 * @p: Task structure to be checked.
1124 *
1125 * Test if a process is not yet dead (at most zombie state)
1126 * If pid_alive fails, then pointers within the task structure
1127 * can be stale and must not be dereferenced.
1128 */
1129static inline int pid_alive(struct task_struct *p)
1130{
1131        return p->pids[PIDTYPE_PID].pid != NULL;
1132}
1133
1134/**
1135 * is_init - check if a task structure is init
1136 * @tsk: Task structure to be checked.
1137 *
1138 * Check if a task structure is the first user space task the kernel created.
1139 */
1140static inline int is_init(struct task_struct *tsk)
1141{
1142        return tsk->pid == 1;
1143}
1144
1145extern struct pid *cad_pid;
1146
1147extern void free_task(struct task_struct *tsk);
1148#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1149
1150extern void __put_task_struct(struct task_struct *t);
1151
1152static inline void put_task_struct(struct task_struct *t)
1153{
1154        if (atomic_dec_and_test(&t->usage))
1155                __put_task_struct(t);
1156}
1157
1158/*
1159 * Per process flags
1160 */
1161#define PF_ALIGNWARN    0x00000001      /* Print alignment warning msgs */
1162                                        /* Not implemented yet, only for 486*/
1163#define PF_STARTING     0x00000002      /* being created */
1164#define PF_EXITING      0x00000004      /* getting shut down */
1165#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1166#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1167#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1168#define PF_DUMPCORE     0x00000200      /* dumped core */
1169#define PF_SIGNALED     0x00000400      /* killed by a signal */
1170#define PF_MEMALLOC     0x00000800      /* Allocating memory */
1171#define PF_FLUSHER      0x00001000      /* responsible for disk writeback */
1172#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1173#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1174#define PF_FROZEN       0x00010000      /* frozen for system suspend */
1175#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1176#define PF_KSWAPD       0x00040000      /* I am kswapd */
1177#define PF_SWAPOFF      0x00080000      /* I am in swapoff */
1178#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1179#define PF_BORROWED_MM  0x00200000      /* I am a kthread doing use_mm */
1180#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1181#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1182#define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1183#define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1184#define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
1185#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1186#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezeable */
1187
1188/*
1189 * Only the _current_ task can read/write to tsk->flags, but other
1190 * tasks can access tsk->flags in readonly mode for example
1191 * with tsk_used_math (like during threaded core dumping).
1192 * There is however an exception to this rule during ptrace
1193 * or during fork: the ptracer task is allowed to write to the
1194 * child->flags of its traced child (same goes for fork, the parent
1195 * can write to the child->flags), because we're guaranteed the
1196 * child is not running and in turn not changing child->flags
1197 * at the same time the parent does it.
1198 */
1199#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1200#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1201#define clear_used_math() clear_stopped_child_used_math(current)
1202#define set_used_math() set_stopped_child_used_math(current)
1203#define conditional_stopped_child_used_math(condition, child) \
1204        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1205#define conditional_used_math(condition) \
1206        conditional_stopped_child_used_math(condition, current)
1207#define copy_to_stopped_child_used_math(child) \
1208        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1209/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1210#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1211#define used_math() tsk_used_math(current)
1212
1213#ifdef CONFIG_SMP
1214extern int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask);
1215#else
1216static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1217{
1218        if (!cpu_isset(0, new_mask))
1219                return -EINVAL;
1220        return 0;
1221}
1222#endif
1223
1224extern unsigned long long sched_clock(void);
1225extern unsigned long long
1226current_sched_time(const struct task_struct *current_task);
1227
1228/* sched_exec is called by processes performing an exec */
1229#ifdef CONFIG_SMP
1230extern void sched_exec(void);
1231#else
1232#define sched_exec()   {}
1233#endif
1234
1235#ifdef CONFIG_HOTPLUG_CPU
1236extern void idle_task_exit(void);
1237#else
1238static inline void idle_task_exit(void) {}
1239#endif
1240
1241extern void sched_idle_next(void);
1242
1243#ifdef CONFIG_RT_MUTEXES
1244extern int rt_mutex_getprio(struct task_struct *p);
1245extern void rt_mutex_setprio(struct task_struct *p, int prio);
1246extern void rt_mutex_adjust_pi(struct task_struct *p);
1247#else
1248static inline int rt_mutex_getprio(struct task_struct *p)
1249{
1250        return p->normal_prio;
1251}
1252# define rt_mutex_adjust_pi(p)          do { } while (0)
1253#endif
1254
1255extern void set_user_nice(struct task_struct *p, long nice);
1256extern int task_prio(const struct task_struct *p);
1257extern int task_nice(const struct task_struct *p);
1258extern int can_nice(const struct task_struct *p, const int nice);
1259extern int task_curr(const struct task_struct *p);
1260extern int idle_cpu(int cpu);
1261extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1262extern struct task_struct *idle_task(int cpu);
1263extern struct task_struct *curr_task(int cpu);
1264extern void set_curr_task(int cpu, struct task_struct *p);
1265
1266void yield(void);
1267
1268/*
1269 * The default (Linux) execution domain.
1270 */
1271extern struct exec_domain       default_exec_domain;
1272
1273union thread_union {
1274        struct thread_info thread_info;
1275        unsigned long stack[THREAD_SIZE/sizeof(long)];
1276};
1277
1278#ifndef __HAVE_ARCH_KSTACK_END
1279static inline int kstack_end(void *addr)
1280{
1281        /* Reliable end of stack detection:
1282         * Some APM bios versions misalign the stack
1283         */
1284        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1285}
1286#endif
1287
1288extern union thread_union init_thread_union;
1289extern struct task_struct init_task;
1290
1291extern struct   mm_struct init_mm;
1292
1293#define find_task_by_pid(nr)    find_task_by_pid_type(PIDTYPE_PID, nr)
1294extern struct task_struct *find_task_by_pid_type(int type, int pid);
1295extern void __set_special_pids(pid_t session, pid_t pgrp);
1296
1297/* per-UID process charging. */
1298extern struct user_struct * alloc_uid(uid_t);
1299static inline struct user_struct *get_uid(struct user_struct *u)
1300{
1301        atomic_inc(&u->__count);
1302        return u;
1303}
1304extern void free_uid(struct user_struct *);
1305extern void switch_uid(struct user_struct *);
1306
1307#include <asm/current.h>
1308
1309extern void do_timer(unsigned long ticks);
1310
1311extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
1312extern int FASTCALL(wake_up_process(struct task_struct * tsk));
1313extern void FASTCALL(wake_up_new_task(struct task_struct * tsk,
1314                                                unsigned long clone_flags));
1315#ifdef CONFIG_SMP
1316 extern void kick_process(struct task_struct *tsk);
1317#else
1318 static inline void kick_process(struct task_struct *tsk) { }
1319#endif
1320extern void FASTCALL(sched_fork(struct task_struct * p, int clone_flags));
1321extern void FASTCALL(sched_exit(struct task_struct * p));
1322
1323extern int in_group_p(gid_t);
1324extern int in_egroup_p(gid_t);
1325
1326extern void proc_caches_init(void);
1327extern void flush_signals(struct task_struct *);
1328extern void ignore_signals(struct task_struct *);
1329extern void flush_signal_handlers(struct task_struct *, int force_default);
1330extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1331
1332static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1333{
1334        unsigned long flags;
1335        int ret;
1336
1337        spin_lock_irqsave(&tsk->sighand->siglock, flags);
1338        ret = dequeue_signal(tsk, mask, info);
1339        spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1340
1341        return ret;
1342}       
1343
1344extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1345                              sigset_t *mask);
1346extern void unblock_all_signals(void);
1347extern void release_task(struct task_struct * p);
1348extern int send_sig_info(int, struct siginfo *, struct task_struct *);
1349extern int send_group_sig_info(int, struct siginfo *, struct task_struct *);
1350extern int force_sigsegv(int, struct task_struct *);
1351extern int force_sig_info(int, struct siginfo *, struct task_struct *);
1352extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
1353extern int kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
1354extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
1355extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
1356extern int kill_pgrp(struct pid *pid, int sig, int priv);
1357extern int kill_pid(struct pid *pid, int sig, int priv);
1358extern int kill_proc_info(int, struct siginfo *, pid_t);
1359extern void do_notify_parent(struct task_struct *, int);
1360extern void force_sig(int, struct task_struct *);
1361extern void force_sig_specific(int, struct task_struct *);
1362extern int send_sig(int, struct task_struct *, int);
1363extern void zap_other_threads(struct task_struct *p);
1364extern int kill_proc(pid_t, int, int);
1365extern struct sigqueue *sigqueue_alloc(void);
1366extern void sigqueue_free(struct sigqueue *);
1367extern int send_sigqueue(int, struct sigqueue *,  struct task_struct *);
1368extern int send_group_sigqueue(int, struct sigqueue *,  struct task_struct *);
1369extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
1370extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1371
1372static inline int kill_cad_pid(int sig, int priv)
1373{
1374        return kill_pid(cad_pid, sig, priv);
1375}
1376
1377/* These can be the second arg to send_sig_info/send_group_sig_info.  */
1378#define SEND_SIG_NOINFO ((struct siginfo *) 0)
1379#define SEND_SIG_PRIV   ((struct siginfo *) 1)
1380#define SEND_SIG_FORCED ((struct siginfo *) 2)
1381
1382static inline int is_si_special(const struct siginfo *info)
1383{
1384        return info <= SEND_SIG_FORCED;
1385}
1386
1387/* True if we are on the alternate signal stack.  */
1388
1389static inline int on_sig_stack(unsigned long sp)
1390{
1391        return (sp - current->sas_ss_sp < current->sas_ss_size);
1392}
1393
1394static inline int sas_ss_flags(unsigned long sp)
1395{
1396        return (current->sas_ss_size == 0 ? SS_DISABLE
1397                : on_sig_stack(sp) ? SS_ONSTACK : 0);
1398}
1399
1400/*
1401 * Routines for handling mm_structs
1402 */
1403extern struct mm_struct * mm_alloc(void);
1404
1405/* mmdrop drops the mm and the page tables */
1406extern void FASTCALL(__mmdrop(struct mm_struct *));
1407static inline void mmdrop(struct mm_struct * mm)
1408{
1409        if (atomic_dec_and_test(&mm->mm_count))
1410                __mmdrop(mm);
1411}
1412
1413/* mmput gets rid of the mappings and all user-space */
1414extern void mmput(struct mm_struct *);
1415/* Grab a reference to a task's mm, if it is not already going away */
1416extern struct mm_struct *get_task_mm(struct task_struct *task);
1417/* Remove the current tasks stale references to the old mm_struct */
1418extern void mm_release(struct task_struct *, struct mm_struct *);
1419
1420extern int  copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
1421extern void flush_thread(void);
1422extern void exit_thread(void);
1423
1424extern void exit_files(struct task_struct *);
1425extern void __cleanup_signal(struct signal_struct *);
1426extern void __cleanup_sighand(struct sighand_struct *);
1427extern void exit_itimers(struct signal_struct *);
1428
1429extern NORET_TYPE void do_group_exit(int);
1430
1431extern void daemonize(const char *, ...);
1432extern int allow_signal(int);
1433extern int disallow_signal(int);
1434
1435extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1436extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
1437struct task_struct *fork_idle(int);
1438
1439extern void set_task_comm(struct task_struct *tsk, char *from);
1440extern void get_task_comm(char *to, struct task_struct *tsk);
1441
1442#ifdef CONFIG_SMP
1443extern void wait_task_inactive(struct task_struct * p);
1444#else
1445#define wait_task_inactive(p)   do { } while (0)
1446#endif
1447
1448#define remove_parent(p)        list_del_init(&(p)->sibling)
1449#define add_parent(p)           list_add_tail(&(p)->sibling,&(p)->parent->children)
1450
1451#define next_task(p)    list_entry(rcu_dereference((p)->tasks.next), struct task_struct, tasks)
1452
1453#define for_each_process(p) \
1454        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
1455
1456/*
1457 * Careful: do_each_thread/while_each_thread is a double loop so
1458 *          'break' will not work as expected - use goto instead.
1459 */
1460#define do_each_thread(g, t) \
1461        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
1462
1463#define while_each_thread(g, t) \
1464        while ((t = next_thread(t)) != g)
1465
1466/* de_thread depends on thread_group_leader not being a pid based check */
1467#define thread_group_leader(p)  (p == p->group_leader)
1468
1469/* Do to the insanities of de_thread it is possible for a process
1470 * to have the pid of the thread group leader without actually being
1471 * the thread group leader.  For iteration through the pids in proc
1472 * all we care about is that we have a task with the appropriate
1473 * pid, we don't actually care if we have the right task.
1474 */
1475static inline int has_group_leader_pid(struct task_struct *p)
1476{
1477        return p->pid == p->tgid;
1478}
1479
1480static inline struct task_struct *next_thread(const struct task_struct *p)
1481{
1482        return list_entry(rcu_dereference(p->thread_group.next),
1483                          struct task_struct, thread_group);
1484}
1485
1486static inline int thread_group_empty(struct task_struct *p)
1487{
1488        return list_empty(&p->thread_group);
1489}
1490
1491#define delay_group_leader(p) \
1492                (thread_group_leader(p) && !thread_group_empty(p))
1493
1494/*
1495 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
1496 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
1497 * pins the final release of task.io_context.  Also protects ->cpuset.
1498 *
1499 * Nests both inside and outside of read_lock(&tasklist_lock).
1500 * It must not be nested with write_lock_irq(&tasklist_lock),
1501 * neither inside nor outside.
1502 */
1503static inline void task_lock(struct task_struct *p)
1504{
1505        spin_lock(&p->alloc_lock);
1506}
1507
1508static inline void task_unlock(struct task_struct *p)
1509{
1510        spin_unlock(&p->alloc_lock);
1511}
1512
1513extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
1514                                                        unsigned long *flags);
1515
1516static inline void unlock_task_sighand(struct task_struct *tsk,
1517                                                unsigned long *flags)
1518{
1519        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
1520}
1521
1522#ifndef __HAVE_THREAD_FUNCTIONS
1523
1524#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
1525#define task_stack_page(task)   ((task)->stack)
1526
1527static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
1528{
1529        *task_thread_info(p) = *task_thread_info(org);
1530        task_thread_info(p)->task = p;
1531}
1532
1533static inline unsigned long *end_of_stack(struct task_struct *p)
1534{
1535        return (unsigned long *)(task_thread_info(p) + 1);
1536}
1537
1538#endif
1539
1540/* set thread flags in other task's structures
1541 * - see asm/thread_info.h for TIF_xxxx flags available
1542 */
1543static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1544{
1545        set_ti_thread_flag(task_thread_info(tsk), flag);
1546}
1547
1548static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1549{
1550        clear_ti_thread_flag(task_thread_info(tsk), flag);
1551}
1552
1553static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1554{
1555        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1556}
1557
1558static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1559{
1560        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1561}
1562
1563static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1564{
1565        return test_ti_thread_flag(task_thread_info(tsk), flag);
1566}
1567
1568static inline void set_tsk_need_resched(struct task_struct *tsk)
1569{
1570        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1571}
1572
1573static inline void clear_tsk_need_resched(struct task_struct *tsk)
1574{
1575        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1576}
1577
1578static inline int signal_pending(struct task_struct *p)
1579{
1580        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
1581}
1582  
1583static inline int need_resched(void)
1584{
1585        return unlikely(test_thread_flag(TIF_NEED_RESCHED));
1586}
1587
1588/*
1589 * cond_resched() and cond_resched_lock(): latency reduction via
1590 * explicit rescheduling in places that are safe. The return
1591 * value indicates whether a reschedule was done in fact.
1592 * cond_resched_lock() will drop the spinlock before scheduling,
1593 * cond_resched_softirq() will enable bhs before scheduling.
1594 */
1595extern int cond_resched(void);
1596extern int cond_resched_lock(spinlock_t * lock);
1597extern int cond_resched_softirq(void);
1598
1599/*
1600 * Does a critical section need to be broken due to another
1601 * task waiting?:
1602 */
1603#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP)
1604# define need_lockbreak(lock) ((lock)->break_lock)
1605#else
1606# define need_lockbreak(lock) 0
1607#endif
1608
1609/*
1610 * Does a critical section need to be broken due to another
1611 * task waiting or preemption being signalled:
1612 */
1613static inline int lock_need_resched(spinlock_t *lock)
1614{
1615        if (need_lockbreak(lock) || need_resched())
1616                return 1;
1617        return 0;
1618}
1619
1620/*
1621 * Reevaluate whether the task has signals pending delivery.
1622 * Wake the task if so.
1623 * This is required every time the blocked sigset_t changes.
1624 * callers must hold sighand->siglock.
1625 */
1626extern void recalc_sigpending_and_wake(struct task_struct *t);
1627extern void recalc_sigpending(void);
1628
1629extern void signal_wake_up(struct task_struct *t, int resume_stopped);
1630
1631/*
1632 * Wrappers for p->thread_info->cpu access. No-op on UP.
1633 */
1634#ifdef CONFIG_SMP
1635
1636static inline unsigned int task_cpu(const struct task_struct *p)
1637{
1638        return task_thread_info(p)->cpu;
1639}
1640
1641static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1642{
1643        task_thread_info(p)->cpu = cpu;
1644}
1645
1646#else
1647
1648static inline unsigned int task_cpu(const struct task_struct *p)
1649{
1650        return 0;
1651}
1652
1653static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1654{
1655}
1656
1657#endif /* CONFIG_SMP */
1658
1659#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1660extern void arch_pick_mmap_layout(struct mm_struct *mm);
1661#else
1662static inline void arch_pick_mmap_layout(struct mm_struct *mm)
1663{
1664        mm->mmap_base = TASK_UNMAPPED_BASE;
1665        mm->get_unmapped_area = arch_get_unmapped_area;
1666        mm->unmap_area = arch_unmap_area;
1667}
1668#endif
1669
1670extern long sched_setaffinity(pid_t pid, cpumask_t new_mask);
1671extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
1672
1673extern int sched_mc_power_savings, sched_smt_power_savings;
1674
1675extern void normalize_rt_tasks(void);
1676
1677#ifdef CONFIG_TASK_XACCT
1678static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
1679{
1680        tsk->rchar += amt;
1681}
1682
1683static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
1684{
1685        tsk->wchar += amt;
1686}
1687
1688static inline void inc_syscr(struct task_struct *tsk)
1689{
1690        tsk->syscr++;
1691}
1692
1693static inline void inc_syscw(struct task_struct *tsk)
1694{
1695        tsk->syscw++;
1696}
1697#else
1698static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
1699{
1700}
1701
1702static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
1703{
1704}
1705
1706static inline void inc_syscr(struct task_struct *tsk)
1707{
1708}
1709
1710static inline void inc_syscw(struct task_struct *tsk)
1711{
1712}
1713#endif
1714
1715#endif /* __KERNEL__ */
1716
1717#endif
1718
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