linux/include/linux/sched.h
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   1#ifndef _LINUX_SCHED_H
   2#define _LINUX_SCHED_H
   3
   4#include <uapi/linux/sched.h>
   5
   6
   7struct sched_param {
   8        int sched_priority;
   9};
  10
  11#include <asm/param.h>  /* for HZ */
  12
  13#include <linux/capability.h>
  14#include <linux/threads.h>
  15#include <linux/kernel.h>
  16#include <linux/types.h>
  17#include <linux/timex.h>
  18#include <linux/jiffies.h>
  19#include <linux/rbtree.h>
  20#include <linux/thread_info.h>
  21#include <linux/cpumask.h>
  22#include <linux/errno.h>
  23#include <linux/nodemask.h>
  24#include <linux/mm_types.h>
  25#include <linux/preempt_mask.h>
  26
  27#include <asm/page.h>
  28#include <asm/ptrace.h>
  29#include <asm/cputime.h>
  30
  31#include <linux/smp.h>
  32#include <linux/sem.h>
  33#include <linux/signal.h>
  34#include <linux/compiler.h>
  35#include <linux/completion.h>
  36#include <linux/pid.h>
  37#include <linux/percpu.h>
  38#include <linux/topology.h>
  39#include <linux/proportions.h>
  40#include <linux/seccomp.h>
  41#include <linux/rcupdate.h>
  42#include <linux/rculist.h>
  43#include <linux/rtmutex.h>
  44
  45#include <linux/time.h>
  46#include <linux/param.h>
  47#include <linux/resource.h>
  48#include <linux/timer.h>
  49#include <linux/hrtimer.h>
  50#include <linux/task_io_accounting.h>
  51#include <linux/latencytop.h>
  52#include <linux/cred.h>
  53#include <linux/llist.h>
  54#include <linux/uidgid.h>
  55#include <linux/gfp.h>
  56
  57#include <asm/processor.h>
  58
  59struct exec_domain;
  60struct futex_pi_state;
  61struct robust_list_head;
  62struct bio_list;
  63struct fs_struct;
  64struct perf_event_context;
  65struct blk_plug;
  66
  67/*
  68 * List of flags we want to share for kernel threads,
  69 * if only because they are not used by them anyway.
  70 */
  71#define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
  72
  73/*
  74 * These are the constant used to fake the fixed-point load-average
  75 * counting. Some notes:
  76 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
  77 *    a load-average precision of 10 bits integer + 11 bits fractional
  78 *  - if you want to count load-averages more often, you need more
  79 *    precision, or rounding will get you. With 2-second counting freq,
  80 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
  81 *    11 bit fractions.
  82 */
  83extern unsigned long avenrun[];         /* Load averages */
  84extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
  85
  86#define FSHIFT          11              /* nr of bits of precision */
  87#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
  88#define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
  89#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
  90#define EXP_5           2014            /* 1/exp(5sec/5min) */
  91#define EXP_15          2037            /* 1/exp(5sec/15min) */
  92
  93#define CALC_LOAD(load,exp,n) \
  94        load *= exp; \
  95        load += n*(FIXED_1-exp); \
  96        load >>= FSHIFT;
  97
  98extern unsigned long total_forks;
  99extern int nr_threads;
 100DECLARE_PER_CPU(unsigned long, process_counts);
 101extern int nr_processes(void);
 102extern unsigned long nr_running(void);
 103extern unsigned long nr_iowait(void);
 104extern unsigned long nr_iowait_cpu(int cpu);
 105extern unsigned long this_cpu_load(void);
 106
 107
 108extern void calc_global_load(unsigned long ticks);
 109extern void update_cpu_load_nohz(void);
 110
 111extern unsigned long get_parent_ip(unsigned long addr);
 112
 113extern void dump_cpu_task(int cpu);
 114
 115struct seq_file;
 116struct cfs_rq;
 117struct task_group;
 118#ifdef CONFIG_SCHED_DEBUG
 119extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
 120extern void proc_sched_set_task(struct task_struct *p);
 121extern void
 122print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
 123#endif
 124
 125/*
 126 * Task state bitmask. NOTE! These bits are also
 127 * encoded in fs/proc/array.c: get_task_state().
 128 *
 129 * We have two separate sets of flags: task->state
 130 * is about runnability, while task->exit_state are
 131 * about the task exiting. Confusing, but this way
 132 * modifying one set can't modify the other one by
 133 * mistake.
 134 */
 135#define TASK_RUNNING            0
 136#define TASK_INTERRUPTIBLE      1
 137#define TASK_UNINTERRUPTIBLE    2
 138#define __TASK_STOPPED          4
 139#define __TASK_TRACED           8
 140/* in tsk->exit_state */
 141#define EXIT_ZOMBIE             16
 142#define EXIT_DEAD               32
 143/* in tsk->state again */
 144#define TASK_DEAD               64
 145#define TASK_WAKEKILL           128
 146#define TASK_WAKING             256
 147#define TASK_PARKED             512
 148#define TASK_STATE_MAX          1024
 149
 150#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
 151
 152extern char ___assert_task_state[1 - 2*!!(
 153                sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
 154
 155/* Convenience macros for the sake of set_task_state */
 156#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 157#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
 158#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 159
 160/* Convenience macros for the sake of wake_up */
 161#define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 162#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 163
 164/* get_task_state() */
 165#define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 166                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 167                                 __TASK_TRACED)
 168
 169#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
 170#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 171#define task_is_dead(task)      ((task)->exit_state != 0)
 172#define task_is_stopped_or_traced(task) \
 173                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 174#define task_contributes_to_load(task)  \
 175                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 176                                 (task->flags & PF_FROZEN) == 0)
 177
 178#define __set_task_state(tsk, state_value)              \
 179        do { (tsk)->state = (state_value); } while (0)
 180#define set_task_state(tsk, state_value)                \
 181        set_mb((tsk)->state, (state_value))
 182
 183/*
 184 * set_current_state() includes a barrier so that the write of current->state
 185 * is correctly serialised wrt the caller's subsequent test of whether to
 186 * actually sleep:
 187 *
 188 *      set_current_state(TASK_UNINTERRUPTIBLE);
 189 *      if (do_i_need_to_sleep())
 190 *              schedule();
 191 *
 192 * If the caller does not need such serialisation then use __set_current_state()
 193 */
 194#define __set_current_state(state_value)                        \
 195        do { current->state = (state_value); } while (0)
 196#define set_current_state(state_value)          \
 197        set_mb(current->state, (state_value))
 198
 199/* Task command name length */
 200#define TASK_COMM_LEN 16
 201
 202#include <linux/spinlock.h>
 203
 204/*
 205 * This serializes "schedule()" and also protects
 206 * the run-queue from deletions/modifications (but
 207 * _adding_ to the beginning of the run-queue has
 208 * a separate lock).
 209 */
 210extern rwlock_t tasklist_lock;
 211extern spinlock_t mmlist_lock;
 212
 213struct task_struct;
 214
 215#ifdef CONFIG_PROVE_RCU
 216extern int lockdep_tasklist_lock_is_held(void);
 217#endif /* #ifdef CONFIG_PROVE_RCU */
 218
 219extern void sched_init(void);
 220extern void sched_init_smp(void);
 221extern asmlinkage void schedule_tail(struct task_struct *prev);
 222extern void init_idle(struct task_struct *idle, int cpu);
 223extern void init_idle_bootup_task(struct task_struct *idle);
 224
 225extern int runqueue_is_locked(int cpu);
 226
 227#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 228extern void nohz_balance_enter_idle(int cpu);
 229extern void set_cpu_sd_state_idle(void);
 230extern int get_nohz_timer_target(void);
 231#else
 232static inline void nohz_balance_enter_idle(int cpu) { }
 233static inline void set_cpu_sd_state_idle(void) { }
 234#endif
 235
 236/*
 237 * Only dump TASK_* tasks. (0 for all tasks)
 238 */
 239extern void show_state_filter(unsigned long state_filter);
 240
 241static inline void show_state(void)
 242{
 243        show_state_filter(0);
 244}
 245
 246extern void show_regs(struct pt_regs *);
 247
 248/*
 249 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 250 * task), SP is the stack pointer of the first frame that should be shown in the back
 251 * trace (or NULL if the entire call-chain of the task should be shown).
 252 */
 253extern void show_stack(struct task_struct *task, unsigned long *sp);
 254
 255void io_schedule(void);
 256long io_schedule_timeout(long timeout);
 257
 258extern void cpu_init (void);
 259extern void trap_init(void);
 260extern void update_process_times(int user);
 261extern void scheduler_tick(void);
 262
 263extern void sched_show_task(struct task_struct *p);
 264
 265#ifdef CONFIG_LOCKUP_DETECTOR
 266extern void touch_softlockup_watchdog(void);
 267extern void touch_softlockup_watchdog_sync(void);
 268extern void touch_all_softlockup_watchdogs(void);
 269extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
 270                                  void __user *buffer,
 271                                  size_t *lenp, loff_t *ppos);
 272extern unsigned int  softlockup_panic;
 273void lockup_detector_init(void);
 274#else
 275static inline void touch_softlockup_watchdog(void)
 276{
 277}
 278static inline void touch_softlockup_watchdog_sync(void)
 279{
 280}
 281static inline void touch_all_softlockup_watchdogs(void)
 282{
 283}
 284static inline void lockup_detector_init(void)
 285{
 286}
 287#endif
 288
 289#ifdef CONFIG_DETECT_HUNG_TASK
 290void reset_hung_task_detector(void);
 291#else
 292static inline void reset_hung_task_detector(void)
 293{
 294}
 295#endif
 296
 297/* Attach to any functions which should be ignored in wchan output. */
 298#define __sched         __attribute__((__section__(".sched.text")))
 299
 300/* Linker adds these: start and end of __sched functions */
 301extern char __sched_text_start[], __sched_text_end[];
 302
 303/* Is this address in the __sched functions? */
 304extern int in_sched_functions(unsigned long addr);
 305
 306#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 307extern signed long schedule_timeout(signed long timeout);
 308extern signed long schedule_timeout_interruptible(signed long timeout);
 309extern signed long schedule_timeout_killable(signed long timeout);
 310extern signed long schedule_timeout_uninterruptible(signed long timeout);
 311asmlinkage void schedule(void);
 312extern void schedule_preempt_disabled(void);
 313
 314struct nsproxy;
 315struct user_namespace;
 316
 317#ifdef CONFIG_MMU
 318extern void arch_pick_mmap_layout(struct mm_struct *mm);
 319extern unsigned long
 320arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 321                       unsigned long, unsigned long);
 322extern unsigned long
 323arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 324                          unsigned long len, unsigned long pgoff,
 325                          unsigned long flags);
 326#else
 327static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
 328#endif
 329
 330
 331extern void set_dumpable(struct mm_struct *mm, int value);
 332extern int get_dumpable(struct mm_struct *mm);
 333
 334#define SUID_DUMP_DISABLE       0       /* No setuid dumping */
 335#define SUID_DUMP_USER          1       /* Dump as user of process */
 336#define SUID_DUMP_ROOT          2       /* Dump as root */
 337
 338/* mm flags */
 339/* dumpable bits */
 340#define MMF_DUMPABLE      0  /* core dump is permitted */
 341#define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
 342
 343#define MMF_DUMPABLE_BITS 2
 344#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
 345
 346/* coredump filter bits */
 347#define MMF_DUMP_ANON_PRIVATE   2
 348#define MMF_DUMP_ANON_SHARED    3
 349#define MMF_DUMP_MAPPED_PRIVATE 4
 350#define MMF_DUMP_MAPPED_SHARED  5
 351#define MMF_DUMP_ELF_HEADERS    6
 352#define MMF_DUMP_HUGETLB_PRIVATE 7
 353#define MMF_DUMP_HUGETLB_SHARED  8
 354
 355#define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
 356#define MMF_DUMP_FILTER_BITS    7
 357#define MMF_DUMP_FILTER_MASK \
 358        (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 359#define MMF_DUMP_FILTER_DEFAULT \
 360        ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
 361         (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
 362
 363#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
 364# define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
 365#else
 366# define MMF_DUMP_MASK_DEFAULT_ELF      0
 367#endif
 368                                        /* leave room for more dump flags */
 369#define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
 370#define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
 371#define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
 372
 373#define MMF_HAS_UPROBES         19      /* has uprobes */
 374#define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
 375
 376#define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
 377
 378struct sighand_struct {
 379        atomic_t                count;
 380        struct k_sigaction      action[_NSIG];
 381        spinlock_t              siglock;
 382        wait_queue_head_t       signalfd_wqh;
 383};
 384
 385struct pacct_struct {
 386        int                     ac_flag;
 387        long                    ac_exitcode;
 388        unsigned long           ac_mem;
 389        cputime_t               ac_utime, ac_stime;
 390        unsigned long           ac_minflt, ac_majflt;
 391};
 392
 393struct cpu_itimer {
 394        cputime_t expires;
 395        cputime_t incr;
 396        u32 error;
 397        u32 incr_error;
 398};
 399
 400/**
 401 * struct cputime - snaphsot of system and user cputime
 402 * @utime: time spent in user mode
 403 * @stime: time spent in system mode
 404 *
 405 * Gathers a generic snapshot of user and system time.
 406 */
 407struct cputime {
 408        cputime_t utime;
 409        cputime_t stime;
 410};
 411
 412/**
 413 * struct task_cputime - collected CPU time counts
 414 * @utime:              time spent in user mode, in &cputime_t units
 415 * @stime:              time spent in kernel mode, in &cputime_t units
 416 * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
 417 *
 418 * This is an extension of struct cputime that includes the total runtime
 419 * spent by the task from the scheduler point of view.
 420 *
 421 * As a result, this structure groups together three kinds of CPU time
 422 * that are tracked for threads and thread groups.  Most things considering
 423 * CPU time want to group these counts together and treat all three
 424 * of them in parallel.
 425 */
 426struct task_cputime {
 427        cputime_t utime;
 428        cputime_t stime;
 429        unsigned long long sum_exec_runtime;
 430};
 431/* Alternate field names when used to cache expirations. */
 432#define prof_exp        stime
 433#define virt_exp        utime
 434#define sched_exp       sum_exec_runtime
 435
 436#define INIT_CPUTIME    \
 437        (struct task_cputime) {                                 \
 438                .utime = 0,                                     \
 439                .stime = 0,                                     \
 440                .sum_exec_runtime = 0,                          \
 441        }
 442
 443#ifdef CONFIG_PREEMPT_COUNT
 444#define PREEMPT_DISABLED        (1 + PREEMPT_ENABLED)
 445#else
 446#define PREEMPT_DISABLED        PREEMPT_ENABLED
 447#endif
 448
 449/*
 450 * Disable preemption until the scheduler is running.
 451 * Reset by start_kernel()->sched_init()->init_idle().
 452 *
 453 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
 454 * before the scheduler is active -- see should_resched().
 455 */
 456#define INIT_PREEMPT_COUNT      (PREEMPT_DISABLED + PREEMPT_ACTIVE)
 457
 458/**
 459 * struct thread_group_cputimer - thread group interval timer counts
 460 * @cputime:            thread group interval timers.
 461 * @running:            non-zero when there are timers running and
 462 *                      @cputime receives updates.
 463 * @lock:               lock for fields in this struct.
 464 *
 465 * This structure contains the version of task_cputime, above, that is
 466 * used for thread group CPU timer calculations.
 467 */
 468struct thread_group_cputimer {
 469        struct task_cputime cputime;
 470        int running;
 471        raw_spinlock_t lock;
 472};
 473
 474#include <linux/rwsem.h>
 475struct autogroup;
 476
 477/*
 478 * NOTE! "signal_struct" does not have its own
 479 * locking, because a shared signal_struct always
 480 * implies a shared sighand_struct, so locking
 481 * sighand_struct is always a proper superset of
 482 * the locking of signal_struct.
 483 */
 484struct signal_struct {
 485        atomic_t                sigcnt;
 486        atomic_t                live;
 487        int                     nr_threads;
 488
 489        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 490
 491        /* current thread group signal load-balancing target: */
 492        struct task_struct      *curr_target;
 493
 494        /* shared signal handling: */
 495        struct sigpending       shared_pending;
 496
 497        /* thread group exit support */
 498        int                     group_exit_code;
 499        /* overloaded:
 500         * - notify group_exit_task when ->count is equal to notify_count
 501         * - everyone except group_exit_task is stopped during signal delivery
 502         *   of fatal signals, group_exit_task processes the signal.
 503         */
 504        int                     notify_count;
 505        struct task_struct      *group_exit_task;
 506
 507        /* thread group stop support, overloads group_exit_code too */
 508        int                     group_stop_count;
 509        unsigned int            flags; /* see SIGNAL_* flags below */
 510
 511        /*
 512         * PR_SET_CHILD_SUBREAPER marks a process, like a service
 513         * manager, to re-parent orphan (double-forking) child processes
 514         * to this process instead of 'init'. The service manager is
 515         * able to receive SIGCHLD signals and is able to investigate
 516         * the process until it calls wait(). All children of this
 517         * process will inherit a flag if they should look for a
 518         * child_subreaper process at exit.
 519         */
 520        unsigned int            is_child_subreaper:1;
 521        unsigned int            has_child_subreaper:1;
 522
 523        /* POSIX.1b Interval Timers */
 524        int                     posix_timer_id;
 525        struct list_head        posix_timers;
 526
 527        /* ITIMER_REAL timer for the process */
 528        struct hrtimer real_timer;
 529        struct pid *leader_pid;
 530        ktime_t it_real_incr;
 531
 532        /*
 533         * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
 534         * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
 535         * values are defined to 0 and 1 respectively
 536         */
 537        struct cpu_itimer it[2];
 538
 539        /*
 540         * Thread group totals for process CPU timers.
 541         * See thread_group_cputimer(), et al, for details.
 542         */
 543        struct thread_group_cputimer cputimer;
 544
 545        /* Earliest-expiration cache. */
 546        struct task_cputime cputime_expires;
 547
 548        struct list_head cpu_timers[3];
 549
 550        struct pid *tty_old_pgrp;
 551
 552        /* boolean value for session group leader */
 553        int leader;
 554
 555        struct tty_struct *tty; /* NULL if no tty */
 556
 557#ifdef CONFIG_SCHED_AUTOGROUP
 558        struct autogroup *autogroup;
 559#endif
 560        /*
 561         * Cumulative resource counters for dead threads in the group,
 562         * and for reaped dead child processes forked by this group.
 563         * Live threads maintain their own counters and add to these
 564         * in __exit_signal, except for the group leader.
 565         */
 566        cputime_t utime, stime, cutime, cstime;
 567        cputime_t gtime;
 568        cputime_t cgtime;
 569#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 570        struct cputime prev_cputime;
 571#endif
 572        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 573        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 574        unsigned long inblock, oublock, cinblock, coublock;
 575        unsigned long maxrss, cmaxrss;
 576        struct task_io_accounting ioac;
 577
 578        /*
 579         * Cumulative ns of schedule CPU time fo dead threads in the
 580         * group, not including a zombie group leader, (This only differs
 581         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 582         * other than jiffies.)
 583         */
 584        unsigned long long sum_sched_runtime;
 585
 586        /*
 587         * We don't bother to synchronize most readers of this at all,
 588         * because there is no reader checking a limit that actually needs
 589         * to get both rlim_cur and rlim_max atomically, and either one
 590         * alone is a single word that can safely be read normally.
 591         * getrlimit/setrlimit use task_lock(current->group_leader) to
 592         * protect this instead of the siglock, because they really
 593         * have no need to disable irqs.
 594         */
 595        struct rlimit rlim[RLIM_NLIMITS];
 596
 597#ifdef CONFIG_BSD_PROCESS_ACCT
 598        struct pacct_struct pacct;      /* per-process accounting information */
 599#endif
 600#ifdef CONFIG_TASKSTATS
 601        struct taskstats *stats;
 602#endif
 603#ifdef CONFIG_AUDIT
 604        unsigned audit_tty;
 605        unsigned audit_tty_log_passwd;
 606        struct tty_audit_buf *tty_audit_buf;
 607#endif
 608#ifdef CONFIG_CGROUPS
 609        /*
 610         * group_rwsem prevents new tasks from entering the threadgroup and
 611         * member tasks from exiting,a more specifically, setting of
 612         * PF_EXITING.  fork and exit paths are protected with this rwsem
 613         * using threadgroup_change_begin/end().  Users which require
 614         * threadgroup to remain stable should use threadgroup_[un]lock()
 615         * which also takes care of exec path.  Currently, cgroup is the
 616         * only user.
 617         */
 618        struct rw_semaphore group_rwsem;
 619#endif
 620
 621        oom_flags_t oom_flags;
 622        short oom_score_adj;            /* OOM kill score adjustment */
 623        short oom_score_adj_min;        /* OOM kill score adjustment min value.
 624                                         * Only settable by CAP_SYS_RESOURCE. */
 625
 626        struct mutex cred_guard_mutex;  /* guard against foreign influences on
 627                                         * credential calculations
 628                                         * (notably. ptrace) */
 629};
 630
 631/*
 632 * Bits in flags field of signal_struct.
 633 */
 634#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 635#define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
 636#define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
 637#define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
 638/*
 639 * Pending notifications to parent.
 640 */
 641#define SIGNAL_CLD_STOPPED      0x00000010
 642#define SIGNAL_CLD_CONTINUED    0x00000020
 643#define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
 644
 645#define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
 646
 647/* If true, all threads except ->group_exit_task have pending SIGKILL */
 648static inline int signal_group_exit(const struct signal_struct *sig)
 649{
 650        return  (sig->flags & SIGNAL_GROUP_EXIT) ||
 651                (sig->group_exit_task != NULL);
 652}
 653
 654/*
 655 * Some day this will be a full-fledged user tracking system..
 656 */
 657struct user_struct {
 658        atomic_t __count;       /* reference count */
 659        atomic_t processes;     /* How many processes does this user have? */
 660        atomic_t files;         /* How many open files does this user have? */
 661        atomic_t sigpending;    /* How many pending signals does this user have? */
 662#ifdef CONFIG_INOTIFY_USER
 663        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 664        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 665#endif
 666#ifdef CONFIG_FANOTIFY
 667        atomic_t fanotify_listeners;
 668#endif
 669#ifdef CONFIG_EPOLL
 670        atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
 671#endif
 672#ifdef CONFIG_POSIX_MQUEUE
 673        /* protected by mq_lock */
 674        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 675#endif
 676        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 677
 678#ifdef CONFIG_KEYS
 679        struct key *uid_keyring;        /* UID specific keyring */
 680        struct key *session_keyring;    /* UID's default session keyring */
 681#endif
 682
 683        /* Hash table maintenance information */
 684        struct hlist_node uidhash_node;
 685        kuid_t uid;
 686
 687#ifdef CONFIG_PERF_EVENTS
 688        atomic_long_t locked_vm;
 689#endif
 690};
 691
 692extern int uids_sysfs_init(void);
 693
 694extern struct user_struct *find_user(kuid_t);
 695
 696extern struct user_struct root_user;
 697#define INIT_USER (&root_user)
 698
 699
 700struct backing_dev_info;
 701struct reclaim_state;
 702
 703#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 704struct sched_info {
 705        /* cumulative counters */
 706        unsigned long pcount;         /* # of times run on this cpu */
 707        unsigned long long run_delay; /* time spent waiting on a runqueue */
 708
 709        /* timestamps */
 710        unsigned long long last_arrival,/* when we last ran on a cpu */
 711                           last_queued; /* when we were last queued to run */
 712};
 713#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
 714
 715#ifdef CONFIG_TASK_DELAY_ACCT
 716struct task_delay_info {
 717        spinlock_t      lock;
 718        unsigned int    flags;  /* Private per-task flags */
 719
 720        /* For each stat XXX, add following, aligned appropriately
 721         *
 722         * struct timespec XXX_start, XXX_end;
 723         * u64 XXX_delay;
 724         * u32 XXX_count;
 725         *
 726         * Atomicity of updates to XXX_delay, XXX_count protected by
 727         * single lock above (split into XXX_lock if contention is an issue).
 728         */
 729
 730        /*
 731         * XXX_count is incremented on every XXX operation, the delay
 732         * associated with the operation is added to XXX_delay.
 733         * XXX_delay contains the accumulated delay time in nanoseconds.
 734         */
 735        struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
 736        u64 blkio_delay;        /* wait for sync block io completion */
 737        u64 swapin_delay;       /* wait for swapin block io completion */
 738        u32 blkio_count;        /* total count of the number of sync block */
 739                                /* io operations performed */
 740        u32 swapin_count;       /* total count of the number of swapin block */
 741                                /* io operations performed */
 742
 743        struct timespec freepages_start, freepages_end;
 744        u64 freepages_delay;    /* wait for memory reclaim */
 745        u32 freepages_count;    /* total count of memory reclaim */
 746};
 747#endif  /* CONFIG_TASK_DELAY_ACCT */
 748
 749static inline int sched_info_on(void)
 750{
 751#ifdef CONFIG_SCHEDSTATS
 752        return 1;
 753#elif defined(CONFIG_TASK_DELAY_ACCT)
 754        extern int delayacct_on;
 755        return delayacct_on;
 756#else
 757        return 0;
 758#endif
 759}
 760
 761enum cpu_idle_type {
 762        CPU_IDLE,
 763        CPU_NOT_IDLE,
 764        CPU_NEWLY_IDLE,
 765        CPU_MAX_IDLE_TYPES
 766};
 767
 768/*
 769 * Increase resolution of cpu_power calculations
 770 */
 771#define SCHED_POWER_SHIFT       10
 772#define SCHED_POWER_SCALE       (1L << SCHED_POWER_SHIFT)
 773
 774/*
 775 * sched-domains (multiprocessor balancing) declarations:
 776 */
 777#ifdef CONFIG_SMP
 778#define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
 779#define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
 780#define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
 781#define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
 782#define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
 783#define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
 784#define SD_SHARE_CPUPOWER       0x0080  /* Domain members share cpu power */
 785#define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
 786#define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
 787#define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
 788#define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
 789#define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
 790#define SD_NUMA                 0x4000  /* cross-node balancing */
 791
 792extern int __weak arch_sd_sibiling_asym_packing(void);
 793
 794struct sched_domain_attr {
 795        int relax_domain_level;
 796};
 797
 798#define SD_ATTR_INIT    (struct sched_domain_attr) {    \
 799        .relax_domain_level = -1,                       \
 800}
 801
 802extern int sched_domain_level_max;
 803
 804struct sched_group;
 805
 806struct sched_domain {
 807        /* These fields must be setup */
 808        struct sched_domain *parent;    /* top domain must be null terminated */
 809        struct sched_domain *child;     /* bottom domain must be null terminated */
 810        struct sched_group *groups;     /* the balancing groups of the domain */
 811        unsigned long min_interval;     /* Minimum balance interval ms */
 812        unsigned long max_interval;     /* Maximum balance interval ms */
 813        unsigned int busy_factor;       /* less balancing by factor if busy */
 814        unsigned int imbalance_pct;     /* No balance until over watermark */
 815        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
 816        unsigned int busy_idx;
 817        unsigned int idle_idx;
 818        unsigned int newidle_idx;
 819        unsigned int wake_idx;
 820        unsigned int forkexec_idx;
 821        unsigned int smt_gain;
 822
 823        int nohz_idle;                  /* NOHZ IDLE status */
 824        int flags;                      /* See SD_* */
 825        int level;
 826
 827        /* Runtime fields. */
 828        unsigned long last_balance;     /* init to jiffies. units in jiffies */
 829        unsigned int balance_interval;  /* initialise to 1. units in ms. */
 830        unsigned int nr_balance_failed; /* initialise to 0 */
 831
 832        /* idle_balance() stats */
 833        u64 max_newidle_lb_cost;
 834        unsigned long next_decay_max_lb_cost;
 835
 836#ifdef CONFIG_SCHEDSTATS
 837        /* load_balance() stats */
 838        unsigned int lb_count[CPU_MAX_IDLE_TYPES];
 839        unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
 840        unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
 841        unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
 842        unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
 843        unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
 844        unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
 845        unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
 846
 847        /* Active load balancing */
 848        unsigned int alb_count;
 849        unsigned int alb_failed;
 850        unsigned int alb_pushed;
 851
 852        /* SD_BALANCE_EXEC stats */
 853        unsigned int sbe_count;
 854        unsigned int sbe_balanced;
 855        unsigned int sbe_pushed;
 856
 857        /* SD_BALANCE_FORK stats */
 858        unsigned int sbf_count;
 859        unsigned int sbf_balanced;
 860        unsigned int sbf_pushed;
 861
 862        /* try_to_wake_up() stats */
 863        unsigned int ttwu_wake_remote;
 864        unsigned int ttwu_move_affine;
 865        unsigned int ttwu_move_balance;
 866#endif
 867#ifdef CONFIG_SCHED_DEBUG
 868        char *name;
 869#endif
 870        union {
 871                void *private;          /* used during construction */
 872                struct rcu_head rcu;    /* used during destruction */
 873        };
 874
 875        unsigned int span_weight;
 876        /*
 877         * Span of all CPUs in this domain.
 878         *
 879         * NOTE: this field is variable length. (Allocated dynamically
 880         * by attaching extra space to the end of the structure,
 881         * depending on how many CPUs the kernel has booted up with)
 882         */
 883        unsigned long span[0];
 884};
 885
 886static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
 887{
 888        return to_cpumask(sd->span);
 889}
 890
 891extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 892                                    struct sched_domain_attr *dattr_new);
 893
 894/* Allocate an array of sched domains, for partition_sched_domains(). */
 895cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
 896void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
 897
 898bool cpus_share_cache(int this_cpu, int that_cpu);
 899
 900#else /* CONFIG_SMP */
 901
 902struct sched_domain_attr;
 903
 904static inline void
 905partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 906                        struct sched_domain_attr *dattr_new)
 907{
 908}
 909
 910static inline bool cpus_share_cache(int this_cpu, int that_cpu)
 911{
 912        return true;
 913}
 914
 915#endif  /* !CONFIG_SMP */
 916
 917
 918struct io_context;                      /* See blkdev.h */
 919
 920
 921#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
 922extern void prefetch_stack(struct task_struct *t);
 923#else
 924static inline void prefetch_stack(struct task_struct *t) { }
 925#endif
 926
 927struct audit_context;           /* See audit.c */
 928struct mempolicy;
 929struct pipe_inode_info;
 930struct uts_namespace;
 931
 932struct load_weight {
 933        unsigned long weight;
 934        u32 inv_weight;
 935};
 936
 937struct sched_avg {
 938        /*
 939         * These sums represent an infinite geometric series and so are bound
 940         * above by 1024/(1-y).  Thus we only need a u32 to store them for all
 941         * choices of y < 1-2^(-32)*1024.
 942         */
 943        u32 runnable_avg_sum, runnable_avg_period;
 944        u64 last_runnable_update;
 945        s64 decay_count;
 946        unsigned long load_avg_contrib;
 947};
 948
 949#ifdef CONFIG_SCHEDSTATS
 950struct sched_statistics {
 951        u64                     wait_start;
 952        u64                     wait_max;
 953        u64                     wait_count;
 954        u64                     wait_sum;
 955        u64                     iowait_count;
 956        u64                     iowait_sum;
 957
 958        u64                     sleep_start;
 959        u64                     sleep_max;
 960        s64                     sum_sleep_runtime;
 961
 962        u64                     block_start;
 963        u64                     block_max;
 964        u64                     exec_max;
 965        u64                     slice_max;
 966
 967        u64                     nr_migrations_cold;
 968        u64                     nr_failed_migrations_affine;
 969        u64                     nr_failed_migrations_running;
 970        u64                     nr_failed_migrations_hot;
 971        u64                     nr_forced_migrations;
 972
 973        u64                     nr_wakeups;
 974        u64                     nr_wakeups_sync;
 975        u64                     nr_wakeups_migrate;
 976        u64                     nr_wakeups_local;
 977        u64                     nr_wakeups_remote;
 978        u64                     nr_wakeups_affine;
 979        u64                     nr_wakeups_affine_attempts;
 980        u64                     nr_wakeups_passive;
 981        u64                     nr_wakeups_idle;
 982};
 983#endif
 984
 985struct sched_entity {
 986        struct load_weight      load;           /* for load-balancing */
 987        struct rb_node          run_node;
 988        struct list_head        group_node;
 989        unsigned int            on_rq;
 990
 991        u64                     exec_start;
 992        u64                     sum_exec_runtime;
 993        u64                     vruntime;
 994        u64                     prev_sum_exec_runtime;
 995
 996        u64                     nr_migrations;
 997
 998#ifdef CONFIG_SCHEDSTATS
 999        struct sched_statistics statistics;
1000#endif
1001
1002#ifdef CONFIG_FAIR_GROUP_SCHED
1003        struct sched_entity     *parent;
1004        /* rq on which this entity is (to be) queued: */
1005        struct cfs_rq           *cfs_rq;
1006        /* rq "owned" by this entity/group: */
1007        struct cfs_rq           *my_q;
1008#endif
1009
1010#ifdef CONFIG_SMP
1011        /* Per-entity load-tracking */
1012        struct sched_avg        avg;
1013#endif
1014};
1015
1016struct sched_rt_entity {
1017        struct list_head run_list;
1018        unsigned long timeout;
1019        unsigned long watchdog_stamp;
1020        unsigned int time_slice;
1021
1022        struct sched_rt_entity *back;
1023#ifdef CONFIG_RT_GROUP_SCHED
1024        struct sched_rt_entity  *parent;
1025        /* rq on which this entity is (to be) queued: */
1026        struct rt_rq            *rt_rq;
1027        /* rq "owned" by this entity/group: */
1028        struct rt_rq            *my_q;
1029#endif
1030};
1031
1032
1033struct rcu_node;
1034
1035enum perf_event_task_context {
1036        perf_invalid_context = -1,
1037        perf_hw_context = 0,
1038        perf_sw_context,
1039        perf_nr_task_contexts,
1040};
1041
1042struct task_struct {
1043        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1044        void *stack;
1045        atomic_t usage;
1046        unsigned int flags;     /* per process flags, defined below */
1047        unsigned int ptrace;
1048
1049#ifdef CONFIG_SMP
1050        struct llist_node wake_entry;
1051        int on_cpu;
1052        struct task_struct *last_wakee;
1053        unsigned long wakee_flips;
1054        unsigned long wakee_flip_decay_ts;
1055
1056        int wake_cpu;
1057#endif
1058        int on_rq;
1059
1060        int prio, static_prio, normal_prio;
1061        unsigned int rt_priority;
1062        const struct sched_class *sched_class;
1063        struct sched_entity se;
1064        struct sched_rt_entity rt;
1065#ifdef CONFIG_CGROUP_SCHED
1066        struct task_group *sched_task_group;
1067#endif
1068
1069#ifdef CONFIG_PREEMPT_NOTIFIERS
1070        /* list of struct preempt_notifier: */
1071        struct hlist_head preempt_notifiers;
1072#endif
1073
1074#ifdef CONFIG_BLK_DEV_IO_TRACE
1075        unsigned int btrace_seq;
1076#endif
1077
1078        unsigned int policy;
1079        int nr_cpus_allowed;
1080        cpumask_t cpus_allowed;
1081
1082#ifdef CONFIG_PREEMPT_RCU
1083        int rcu_read_lock_nesting;
1084        char rcu_read_unlock_special;
1085        struct list_head rcu_node_entry;
1086#endif /* #ifdef CONFIG_PREEMPT_RCU */
1087#ifdef CONFIG_TREE_PREEMPT_RCU
1088        struct rcu_node *rcu_blocked_node;
1089#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1090#ifdef CONFIG_RCU_BOOST
1091        struct rt_mutex *rcu_boost_mutex;
1092#endif /* #ifdef CONFIG_RCU_BOOST */
1093
1094#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1095        struct sched_info sched_info;
1096#endif
1097
1098        struct list_head tasks;
1099#ifdef CONFIG_SMP
1100        struct plist_node pushable_tasks;
1101#endif
1102
1103        struct mm_struct *mm, *active_mm;
1104#ifdef CONFIG_COMPAT_BRK
1105        unsigned brk_randomized:1;
1106#endif
1107#if defined(SPLIT_RSS_COUNTING)
1108        struct task_rss_stat    rss_stat;
1109#endif
1110/* task state */
1111        int exit_state;
1112        int exit_code, exit_signal;
1113        int pdeath_signal;  /*  The signal sent when the parent dies  */
1114        unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1115
1116        /* Used for emulating ABI behavior of previous Linux versions */
1117        unsigned int personality;
1118
1119        unsigned did_exec:1;
1120        unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1121                                 * execve */
1122        unsigned in_iowait:1;
1123
1124        /* task may not gain privileges */
1125        unsigned no_new_privs:1;
1126
1127        /* Revert to default priority/policy when forking */
1128        unsigned sched_reset_on_fork:1;
1129        unsigned sched_contributes_to_load:1;
1130
1131        pid_t pid;
1132        pid_t tgid;
1133
1134#ifdef CONFIG_CC_STACKPROTECTOR
1135        /* Canary value for the -fstack-protector gcc feature */
1136        unsigned long stack_canary;
1137#endif
1138        /*
1139         * pointers to (original) parent process, youngest child, younger sibling,
1140         * older sibling, respectively.  (p->father can be replaced with
1141         * p->real_parent->pid)
1142         */
1143        struct task_struct __rcu *real_parent; /* real parent process */
1144        struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1145        /*
1146         * children/sibling forms the list of my natural children
1147         */
1148        struct list_head children;      /* list of my children */
1149        struct list_head sibling;       /* linkage in my parent's children list */
1150        struct task_struct *group_leader;       /* threadgroup leader */
1151
1152        /*
1153         * ptraced is the list of tasks this task is using ptrace on.
1154         * This includes both natural children and PTRACE_ATTACH targets.
1155         * p->ptrace_entry is p's link on the p->parent->ptraced list.
1156         */
1157        struct list_head ptraced;
1158        struct list_head ptrace_entry;
1159
1160        /* PID/PID hash table linkage. */
1161        struct pid_link pids[PIDTYPE_MAX];
1162        struct list_head thread_group;
1163
1164        struct completion *vfork_done;          /* for vfork() */
1165        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1166        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1167
1168        cputime_t utime, stime, utimescaled, stimescaled;
1169        cputime_t gtime;
1170#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1171        struct cputime prev_cputime;
1172#endif
1173#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1174        seqlock_t vtime_seqlock;
1175        unsigned long long vtime_snap;
1176        enum {
1177                VTIME_SLEEPING = 0,
1178                VTIME_USER,
1179                VTIME_SYS,
1180        } vtime_snap_whence;
1181#endif
1182        unsigned long nvcsw, nivcsw; /* context switch counts */
1183        struct timespec start_time;             /* monotonic time */
1184        struct timespec real_start_time;        /* boot based time */
1185/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1186        unsigned long min_flt, maj_flt;
1187
1188        struct task_cputime cputime_expires;
1189        struct list_head cpu_timers[3];
1190
1191/* process credentials */
1192        const struct cred __rcu *real_cred; /* objective and real subjective task
1193                                         * credentials (COW) */
1194        const struct cred __rcu *cred;  /* effective (overridable) subjective task
1195                                         * credentials (COW) */
1196        char comm[TASK_COMM_LEN]; /* executable name excluding path
1197                                     - access with [gs]et_task_comm (which lock
1198                                       it with task_lock())
1199                                     - initialized normally by setup_new_exec */
1200/* file system info */
1201        int link_count, total_link_count;
1202#ifdef CONFIG_SYSVIPC
1203/* ipc stuff */
1204        struct sysv_sem sysvsem;
1205#endif
1206#ifdef CONFIG_DETECT_HUNG_TASK
1207/* hung task detection */
1208        unsigned long last_switch_count;
1209#endif
1210/* CPU-specific state of this task */
1211        struct thread_struct thread;
1212/* filesystem information */
1213        struct fs_struct *fs;
1214/* open file information */
1215        struct files_struct *files;
1216/* namespaces */
1217        struct nsproxy *nsproxy;
1218/* signal handlers */
1219        struct signal_struct *signal;
1220        struct sighand_struct *sighand;
1221
1222        sigset_t blocked, real_blocked;
1223        sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1224        struct sigpending pending;
1225
1226        unsigned long sas_ss_sp;
1227        size_t sas_ss_size;
1228        int (*notifier)(void *priv);
1229        void *notifier_data;
1230        sigset_t *notifier_mask;
1231        struct callback_head *task_works;
1232
1233        struct audit_context *audit_context;
1234#ifdef CONFIG_AUDITSYSCALL
1235        kuid_t loginuid;
1236        unsigned int sessionid;
1237#endif
1238        struct seccomp seccomp;
1239
1240/* Thread group tracking */
1241        u32 parent_exec_id;
1242        u32 self_exec_id;
1243/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1244 * mempolicy */
1245        spinlock_t alloc_lock;
1246
1247        /* Protection of the PI data structures: */
1248        raw_spinlock_t pi_lock;
1249
1250#ifdef CONFIG_RT_MUTEXES
1251        /* PI waiters blocked on a rt_mutex held by this task */
1252        struct plist_head pi_waiters;
1253        /* Deadlock detection and priority inheritance handling */
1254        struct rt_mutex_waiter *pi_blocked_on;
1255#endif
1256
1257#ifdef CONFIG_DEBUG_MUTEXES
1258        /* mutex deadlock detection */
1259        struct mutex_waiter *blocked_on;
1260#endif
1261#ifdef CONFIG_TRACE_IRQFLAGS
1262        unsigned int irq_events;
1263        unsigned long hardirq_enable_ip;
1264        unsigned long hardirq_disable_ip;
1265        unsigned int hardirq_enable_event;
1266        unsigned int hardirq_disable_event;
1267        int hardirqs_enabled;
1268        int hardirq_context;
1269        unsigned long softirq_disable_ip;
1270        unsigned long softirq_enable_ip;
1271        unsigned int softirq_disable_event;
1272        unsigned int softirq_enable_event;
1273        int softirqs_enabled;
1274        int softirq_context;
1275#endif
1276#ifdef CONFIG_LOCKDEP
1277# define MAX_LOCK_DEPTH 48UL
1278        u64 curr_chain_key;
1279        int lockdep_depth;
1280        unsigned int lockdep_recursion;
1281        struct held_lock held_locks[MAX_LOCK_DEPTH];
1282        gfp_t lockdep_reclaim_gfp;
1283#endif
1284
1285/* journalling filesystem info */
1286        void *journal_info;
1287
1288/* stacked block device info */
1289        struct bio_list *bio_list;
1290
1291#ifdef CONFIG_BLOCK
1292/* stack plugging */
1293        struct blk_plug *plug;
1294#endif
1295
1296/* VM state */
1297        struct reclaim_state *reclaim_state;
1298
1299        struct backing_dev_info *backing_dev_info;
1300
1301        struct io_context *io_context;
1302
1303        unsigned long ptrace_message;
1304        siginfo_t *last_siginfo; /* For ptrace use.  */
1305        struct task_io_accounting ioac;
1306#if defined(CONFIG_TASK_XACCT)
1307        u64 acct_rss_mem1;      /* accumulated rss usage */
1308        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1309        cputime_t acct_timexpd; /* stime + utime since last update */
1310#endif
1311#ifdef CONFIG_CPUSETS
1312        nodemask_t mems_allowed;        /* Protected by alloc_lock */
1313        seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1314        int cpuset_mem_spread_rotor;
1315        int cpuset_slab_spread_rotor;
1316#endif
1317#ifdef CONFIG_CGROUPS
1318        /* Control Group info protected by css_set_lock */
1319        struct css_set __rcu *cgroups;
1320        /* cg_list protected by css_set_lock and tsk->alloc_lock */
1321        struct list_head cg_list;
1322#endif
1323#ifdef CONFIG_FUTEX
1324        struct robust_list_head __user *robust_list;
1325#ifdef CONFIG_COMPAT
1326        struct compat_robust_list_head __user *compat_robust_list;
1327#endif
1328        struct list_head pi_state_list;
1329        struct futex_pi_state *pi_state_cache;
1330#endif
1331#ifdef CONFIG_PERF_EVENTS
1332        struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1333        struct mutex perf_event_mutex;
1334        struct list_head perf_event_list;
1335#endif
1336#ifdef CONFIG_NUMA
1337        struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1338        short il_next;
1339        short pref_node_fork;
1340#endif
1341#ifdef CONFIG_NUMA_BALANCING
1342        int numa_scan_seq;
1343        unsigned int numa_scan_period;
1344        unsigned int numa_scan_period_max;
1345        int numa_preferred_nid;
1346        int numa_migrate_deferred;
1347        unsigned long numa_migrate_retry;
1348        u64 node_stamp;                 /* migration stamp  */
1349        struct callback_head numa_work;
1350
1351        struct list_head numa_entry;
1352        struct numa_group *numa_group;
1353
1354        /*
1355         * Exponential decaying average of faults on a per-node basis.
1356         * Scheduling placement decisions are made based on the these counts.
1357         * The values remain static for the duration of a PTE scan
1358         */
1359        unsigned long *numa_faults;
1360        unsigned long total_numa_faults;
1361
1362        /*
1363         * numa_faults_buffer records faults per node during the current
1364         * scan window. When the scan completes, the counts in numa_faults
1365         * decay and these values are copied.
1366         */
1367        unsigned long *numa_faults_buffer;
1368
1369        /*
1370         * numa_faults_locality tracks if faults recorded during the last
1371         * scan window were remote/local. The task scan period is adapted
1372         * based on the locality of the faults with different weights
1373         * depending on whether they were shared or private faults
1374         */
1375        unsigned long numa_faults_locality[2];
1376
1377        unsigned long numa_pages_migrated;
1378#endif /* CONFIG_NUMA_BALANCING */
1379
1380        struct rcu_head rcu;
1381
1382        /*
1383         * cache last used pipe for splice
1384         */
1385        struct pipe_inode_info *splice_pipe;
1386
1387        struct page_frag task_frag;
1388
1389#ifdef  CONFIG_TASK_DELAY_ACCT
1390        struct task_delay_info *delays;
1391#endif
1392#ifdef CONFIG_FAULT_INJECTION
1393        int make_it_fail;
1394#endif
1395        /*
1396         * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1397         * balance_dirty_pages() for some dirty throttling pause
1398         */
1399        int nr_dirtied;
1400        int nr_dirtied_pause;
1401        unsigned long dirty_paused_when; /* start of a write-and-pause period */
1402
1403#ifdef CONFIG_LATENCYTOP
1404        int latency_record_count;
1405        struct latency_record latency_record[LT_SAVECOUNT];
1406#endif
1407        /*
1408         * time slack values; these are used to round up poll() and
1409         * select() etc timeout values. These are in nanoseconds.
1410         */
1411        unsigned long timer_slack_ns;
1412        unsigned long default_timer_slack_ns;
1413
1414#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1415        /* Index of current stored address in ret_stack */
1416        int curr_ret_stack;
1417        /* Stack of return addresses for return function tracing */
1418        struct ftrace_ret_stack *ret_stack;
1419        /* time stamp for last schedule */
1420        unsigned long long ftrace_timestamp;
1421        /*
1422         * Number of functions that haven't been traced
1423         * because of depth overrun.
1424         */
1425        atomic_t trace_overrun;
1426        /* Pause for the tracing */
1427        atomic_t tracing_graph_pause;
1428#endif
1429#ifdef CONFIG_TRACING
1430        /* state flags for use by tracers */
1431        unsigned long trace;
1432        /* bitmask and counter of trace recursion */
1433        unsigned long trace_recursion;
1434#endif /* CONFIG_TRACING */
1435#ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1436        struct memcg_batch_info {
1437                int do_batch;   /* incremented when batch uncharge started */
1438                struct mem_cgroup *memcg; /* target memcg of uncharge */
1439                unsigned long nr_pages; /* uncharged usage */
1440                unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1441        } memcg_batch;
1442        unsigned int memcg_kmem_skip_account;
1443        struct memcg_oom_info {
1444                struct mem_cgroup *memcg;
1445                gfp_t gfp_mask;
1446                int order;
1447                unsigned int may_oom:1;
1448        } memcg_oom;
1449#endif
1450#ifdef CONFIG_UPROBES
1451        struct uprobe_task *utask;
1452#endif
1453#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1454        unsigned int    sequential_io;
1455        unsigned int    sequential_io_avg;
1456#endif
1457};
1458
1459/* Future-safe accessor for struct task_struct's cpus_allowed. */
1460#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1461
1462#define TNF_MIGRATED    0x01
1463#define TNF_NO_GROUP    0x02
1464#define TNF_SHARED      0x04
1465#define TNF_FAULT_LOCAL 0x08
1466
1467#ifdef CONFIG_NUMA_BALANCING
1468extern void task_numa_fault(int last_node, int node, int pages, int flags);
1469extern pid_t task_numa_group_id(struct task_struct *p);
1470extern void set_numabalancing_state(bool enabled);
1471extern void task_numa_free(struct task_struct *p);
1472
1473extern unsigned int sysctl_numa_balancing_migrate_deferred;
1474#else
1475static inline void task_numa_fault(int last_node, int node, int pages,
1476                                   int flags)
1477{
1478}
1479static inline pid_t task_numa_group_id(struct task_struct *p)
1480{
1481        return 0;
1482}
1483static inline void set_numabalancing_state(bool enabled)
1484{
1485}
1486static inline void task_numa_free(struct task_struct *p)
1487{
1488}
1489#endif
1490
1491static inline struct pid *task_pid(struct task_struct *task)
1492{
1493        return task->pids[PIDTYPE_PID].pid;
1494}
1495
1496static inline struct pid *task_tgid(struct task_struct *task)
1497{
1498        return task->group_leader->pids[PIDTYPE_PID].pid;
1499}
1500
1501/*
1502 * Without tasklist or rcu lock it is not safe to dereference
1503 * the result of task_pgrp/task_session even if task == current,
1504 * we can race with another thread doing sys_setsid/sys_setpgid.
1505 */
1506static inline struct pid *task_pgrp(struct task_struct *task)
1507{
1508        return task->group_leader->pids[PIDTYPE_PGID].pid;
1509}
1510
1511static inline struct pid *task_session(struct task_struct *task)
1512{
1513        return task->group_leader->pids[PIDTYPE_SID].pid;
1514}
1515
1516struct pid_namespace;
1517
1518/*
1519 * the helpers to get the task's different pids as they are seen
1520 * from various namespaces
1521 *
1522 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1523 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1524 *                     current.
1525 * task_xid_nr_ns()  : id seen from the ns specified;
1526 *
1527 * set_task_vxid()   : assigns a virtual id to a task;
1528 *
1529 * see also pid_nr() etc in include/linux/pid.h
1530 */
1531pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1532                        struct pid_namespace *ns);
1533
1534static inline pid_t task_pid_nr(struct task_struct *tsk)
1535{
1536        return tsk->pid;
1537}
1538
1539static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1540                                        struct pid_namespace *ns)
1541{
1542        return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1543}
1544
1545static inline pid_t task_pid_vnr(struct task_struct *tsk)
1546{
1547        return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1548}
1549
1550
1551static inline pid_t task_tgid_nr(struct task_struct *tsk)
1552{
1553        return tsk->tgid;
1554}
1555
1556pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1557
1558static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1559{
1560        return pid_vnr(task_tgid(tsk));
1561}
1562
1563
1564static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1565                                        struct pid_namespace *ns)
1566{
1567        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1568}
1569
1570static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1571{
1572        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1573}
1574
1575
1576static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1577                                        struct pid_namespace *ns)
1578{
1579        return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1580}
1581
1582static inline pid_t task_session_vnr(struct task_struct *tsk)
1583{
1584        return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1585}
1586
1587/* obsolete, do not use */
1588static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1589{
1590        return task_pgrp_nr_ns(tsk, &init_pid_ns);
1591}
1592
1593/**
1594 * pid_alive - check that a task structure is not stale
1595 * @p: Task structure to be checked.
1596 *
1597 * Test if a process is not yet dead (at most zombie state)
1598 * If pid_alive fails, then pointers within the task structure
1599 * can be stale and must not be dereferenced.
1600 *
1601 * Return: 1 if the process is alive. 0 otherwise.
1602 */
1603static inline int pid_alive(struct task_struct *p)
1604{
1605        return p->pids[PIDTYPE_PID].pid != NULL;
1606}
1607
1608/**
1609 * is_global_init - check if a task structure is init
1610 * @tsk: Task structure to be checked.
1611 *
1612 * Check if a task structure is the first user space task the kernel created.
1613 *
1614 * Return: 1 if the task structure is init. 0 otherwise.
1615 */
1616static inline int is_global_init(struct task_struct *tsk)
1617{
1618        return tsk->pid == 1;
1619}
1620
1621extern struct pid *cad_pid;
1622
1623extern void free_task(struct task_struct *tsk);
1624#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1625
1626extern void __put_task_struct(struct task_struct *t);
1627
1628static inline void put_task_struct(struct task_struct *t)
1629{
1630        if (atomic_dec_and_test(&t->usage))
1631                __put_task_struct(t);
1632}
1633
1634#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1635extern void task_cputime(struct task_struct *t,
1636                         cputime_t *utime, cputime_t *stime);
1637extern void task_cputime_scaled(struct task_struct *t,
1638                                cputime_t *utimescaled, cputime_t *stimescaled);
1639extern cputime_t task_gtime(struct task_struct *t);
1640#else
1641static inline void task_cputime(struct task_struct *t,
1642                                cputime_t *utime, cputime_t *stime)
1643{
1644        if (utime)
1645                *utime = t->utime;
1646        if (stime)
1647                *stime = t->stime;
1648}
1649
1650static inline void task_cputime_scaled(struct task_struct *t,
1651                                       cputime_t *utimescaled,
1652                                       cputime_t *stimescaled)
1653{
1654        if (utimescaled)
1655                *utimescaled = t->utimescaled;
1656        if (stimescaled)
1657                *stimescaled = t->stimescaled;
1658}
1659
1660static inline cputime_t task_gtime(struct task_struct *t)
1661{
1662        return t->gtime;
1663}
1664#endif
1665extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1666extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1667
1668/*
1669 * Per process flags
1670 */
1671#define PF_EXITING      0x00000004      /* getting shut down */
1672#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1673#define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1674#define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1675#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1676#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1677#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1678#define PF_DUMPCORE     0x00000200      /* dumped core */
1679#define PF_SIGNALED     0x00000400      /* killed by a signal */
1680#define PF_MEMALLOC     0x00000800      /* Allocating memory */
1681#define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1682#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1683#define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
1684#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1685#define PF_FROZEN       0x00010000      /* frozen for system suspend */
1686#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1687#define PF_KSWAPD       0x00040000      /* I am kswapd */
1688#define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
1689#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1690#define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1691#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1692#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1693#define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1694#define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1695#define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
1696#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1697#define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
1698#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1699#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1700#define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1701
1702/*
1703 * Only the _current_ task can read/write to tsk->flags, but other
1704 * tasks can access tsk->flags in readonly mode for example
1705 * with tsk_used_math (like during threaded core dumping).
1706 * There is however an exception to this rule during ptrace
1707 * or during fork: the ptracer task is allowed to write to the
1708 * child->flags of its traced child (same goes for fork, the parent
1709 * can write to the child->flags), because we're guaranteed the
1710 * child is not running and in turn not changing child->flags
1711 * at the same time the parent does it.
1712 */
1713#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1714#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1715#define clear_used_math() clear_stopped_child_used_math(current)
1716#define set_used_math() set_stopped_child_used_math(current)
1717#define conditional_stopped_child_used_math(condition, child) \
1718        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1719#define conditional_used_math(condition) \
1720        conditional_stopped_child_used_math(condition, current)
1721#define copy_to_stopped_child_used_math(child) \
1722        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1723/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1724#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1725#define used_math() tsk_used_math(current)
1726
1727/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
1728static inline gfp_t memalloc_noio_flags(gfp_t flags)
1729{
1730        if (unlikely(current->flags & PF_MEMALLOC_NOIO))
1731                flags &= ~__GFP_IO;
1732        return flags;
1733}
1734
1735static inline unsigned int memalloc_noio_save(void)
1736{
1737        unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
1738        current->flags |= PF_MEMALLOC_NOIO;
1739        return flags;
1740}
1741
1742static inline void memalloc_noio_restore(unsigned int flags)
1743{
1744        current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
1745}
1746
1747/*
1748 * task->jobctl flags
1749 */
1750#define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
1751
1752#define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
1753#define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
1754#define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
1755#define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
1756#define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
1757#define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
1758#define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
1759
1760#define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
1761#define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
1762#define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
1763#define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
1764#define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
1765#define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
1766#define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
1767
1768#define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1769#define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1770
1771extern bool task_set_jobctl_pending(struct task_struct *task,
1772                                    unsigned int mask);
1773extern void task_clear_jobctl_trapping(struct task_struct *task);
1774extern void task_clear_jobctl_pending(struct task_struct *task,
1775                                      unsigned int mask);
1776
1777#ifdef CONFIG_PREEMPT_RCU
1778
1779#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1780#define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1781
1782static inline void rcu_copy_process(struct task_struct *p)
1783{
1784        p->rcu_read_lock_nesting = 0;
1785        p->rcu_read_unlock_special = 0;
1786#ifdef CONFIG_TREE_PREEMPT_RCU
1787        p->rcu_blocked_node = NULL;
1788#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1789#ifdef CONFIG_RCU_BOOST
1790        p->rcu_boost_mutex = NULL;
1791#endif /* #ifdef CONFIG_RCU_BOOST */
1792        INIT_LIST_HEAD(&p->rcu_node_entry);
1793}
1794
1795#else
1796
1797static inline void rcu_copy_process(struct task_struct *p)
1798{
1799}
1800
1801#endif
1802
1803static inline void tsk_restore_flags(struct task_struct *task,
1804                                unsigned long orig_flags, unsigned long flags)
1805{
1806        task->flags &= ~flags;
1807        task->flags |= orig_flags & flags;
1808}
1809
1810#ifdef CONFIG_SMP
1811extern void do_set_cpus_allowed(struct task_struct *p,
1812                               const struct cpumask *new_mask);
1813
1814extern int set_cpus_allowed_ptr(struct task_struct *p,
1815                                const struct cpumask *new_mask);
1816#else
1817static inline void do_set_cpus_allowed(struct task_struct *p,
1818                                      const struct cpumask *new_mask)
1819{
1820}
1821static inline int set_cpus_allowed_ptr(struct task_struct *p,
1822                                       const struct cpumask *new_mask)
1823{
1824        if (!cpumask_test_cpu(0, new_mask))
1825                return -EINVAL;
1826        return 0;
1827}
1828#endif
1829
1830#ifdef CONFIG_NO_HZ_COMMON
1831void calc_load_enter_idle(void);
1832void calc_load_exit_idle(void);
1833#else
1834static inline void calc_load_enter_idle(void) { }
1835static inline void calc_load_exit_idle(void) { }
1836#endif /* CONFIG_NO_HZ_COMMON */
1837
1838#ifndef CONFIG_CPUMASK_OFFSTACK
1839static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1840{
1841        return set_cpus_allowed_ptr(p, &new_mask);
1842}
1843#endif
1844
1845/*
1846 * Do not use outside of architecture code which knows its limitations.
1847 *
1848 * sched_clock() has no promise of monotonicity or bounded drift between
1849 * CPUs, use (which you should not) requires disabling IRQs.
1850 *
1851 * Please use one of the three interfaces below.
1852 */
1853extern unsigned long long notrace sched_clock(void);
1854/*
1855 * See the comment in kernel/sched/clock.c
1856 */
1857extern u64 cpu_clock(int cpu);
1858extern u64 local_clock(void);
1859extern u64 sched_clock_cpu(int cpu);
1860
1861
1862extern void sched_clock_init(void);
1863
1864#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1865static inline void sched_clock_tick(void)
1866{
1867}
1868
1869static inline void sched_clock_idle_sleep_event(void)
1870{
1871}
1872
1873static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1874{
1875}
1876#else
1877/*
1878 * Architectures can set this to 1 if they have specified
1879 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1880 * but then during bootup it turns out that sched_clock()
1881 * is reliable after all:
1882 */
1883extern int sched_clock_stable;
1884
1885extern void sched_clock_tick(void);
1886extern void sched_clock_idle_sleep_event(void);
1887extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1888#endif
1889
1890#ifdef CONFIG_IRQ_TIME_ACCOUNTING
1891/*
1892 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1893 * The reason for this explicit opt-in is not to have perf penalty with
1894 * slow sched_clocks.
1895 */
1896extern void enable_sched_clock_irqtime(void);
1897extern void disable_sched_clock_irqtime(void);
1898#else
1899static inline void enable_sched_clock_irqtime(void) {}
1900static inline void disable_sched_clock_irqtime(void) {}
1901#endif
1902
1903extern unsigned long long
1904task_sched_runtime(struct task_struct *task);
1905
1906/* sched_exec is called by processes performing an exec */
1907#ifdef CONFIG_SMP
1908extern void sched_exec(void);
1909#else
1910#define sched_exec()   {}
1911#endif
1912
1913extern void sched_clock_idle_sleep_event(void);
1914extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1915
1916#ifdef CONFIG_HOTPLUG_CPU
1917extern void idle_task_exit(void);
1918#else
1919static inline void idle_task_exit(void) {}
1920#endif
1921
1922#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
1923extern void wake_up_nohz_cpu(int cpu);
1924#else
1925static inline void wake_up_nohz_cpu(int cpu) { }
1926#endif
1927
1928#ifdef CONFIG_NO_HZ_FULL
1929extern bool sched_can_stop_tick(void);
1930extern u64 scheduler_tick_max_deferment(void);
1931#else
1932static inline bool sched_can_stop_tick(void) { return false; }
1933#endif
1934
1935#ifdef CONFIG_SCHED_AUTOGROUP
1936extern void sched_autogroup_create_attach(struct task_struct *p);
1937extern void sched_autogroup_detach(struct task_struct *p);
1938extern void sched_autogroup_fork(struct signal_struct *sig);
1939extern void sched_autogroup_exit(struct signal_struct *sig);
1940#ifdef CONFIG_PROC_FS
1941extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
1942extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
1943#endif
1944#else
1945static inline void sched_autogroup_create_attach(struct task_struct *p) { }
1946static inline void sched_autogroup_detach(struct task_struct *p) { }
1947static inline void sched_autogroup_fork(struct signal_struct *sig) { }
1948static inline void sched_autogroup_exit(struct signal_struct *sig) { }
1949#endif
1950
1951extern bool yield_to(struct task_struct *p, bool preempt);
1952extern void set_user_nice(struct task_struct *p, long nice);
1953extern int task_prio(const struct task_struct *p);
1954extern int task_nice(const struct task_struct *p);
1955extern int can_nice(const struct task_struct *p, const int nice);
1956extern int task_curr(const struct task_struct *p);
1957extern int idle_cpu(int cpu);
1958extern int sched_setscheduler(struct task_struct *, int,
1959                              const struct sched_param *);
1960extern int sched_setscheduler_nocheck(struct task_struct *, int,
1961                                      const struct sched_param *);
1962extern struct task_struct *idle_task(int cpu);
1963/**
1964 * is_idle_task - is the specified task an idle task?
1965 * @p: the task in question.
1966 *
1967 * Return: 1 if @p is an idle task. 0 otherwise.
1968 */
1969static inline bool is_idle_task(const struct task_struct *p)
1970{
1971        return p->pid == 0;
1972}
1973extern struct task_struct *curr_task(int cpu);
1974extern void set_curr_task(int cpu, struct task_struct *p);
1975
1976void yield(void);
1977
1978/*
1979 * The default (Linux) execution domain.
1980 */
1981extern struct exec_domain       default_exec_domain;
1982
1983union thread_union {
1984        struct thread_info thread_info;
1985        unsigned long stack[THREAD_SIZE/sizeof(long)];
1986};
1987
1988#ifndef __HAVE_ARCH_KSTACK_END
1989static inline int kstack_end(void *addr)
1990{
1991        /* Reliable end of stack detection:
1992         * Some APM bios versions misalign the stack
1993         */
1994        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1995}
1996#endif
1997
1998extern union thread_union init_thread_union;
1999extern struct task_struct init_task;
2000
2001extern struct   mm_struct init_mm;
2002
2003extern struct pid_namespace init_pid_ns;
2004
2005/*
2006 * find a task by one of its numerical ids
2007 *
2008 * find_task_by_pid_ns():
2009 *      finds a task by its pid in the specified namespace
2010 * find_task_by_vpid():
2011 *      finds a task by its virtual pid
2012 *
2013 * see also find_vpid() etc in include/linux/pid.h
2014 */
2015
2016extern struct task_struct *find_task_by_vpid(pid_t nr);
2017extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2018                struct pid_namespace *ns);
2019
2020/* per-UID process charging. */
2021extern struct user_struct * alloc_uid(kuid_t);
2022static inline struct user_struct *get_uid(struct user_struct *u)
2023{
2024        atomic_inc(&u->__count);
2025        return u;
2026}
2027extern void free_uid(struct user_struct *);
2028
2029#include <asm/current.h>
2030
2031extern void xtime_update(unsigned long ticks);
2032
2033extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2034extern int wake_up_process(struct task_struct *tsk);
2035extern void wake_up_new_task(struct task_struct *tsk);
2036#ifdef CONFIG_SMP
2037 extern void kick_process(struct task_struct *tsk);
2038#else
2039 static inline void kick_process(struct task_struct *tsk) { }
2040#endif
2041extern void sched_fork(unsigned long clone_flags, struct task_struct *p);
2042extern void sched_dead(struct task_struct *p);
2043
2044extern void proc_caches_init(void);
2045extern void flush_signals(struct task_struct *);
2046extern void __flush_signals(struct task_struct *);
2047extern void ignore_signals(struct task_struct *);
2048extern void flush_signal_handlers(struct task_struct *, int force_default);
2049extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2050
2051static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2052{
2053        unsigned long flags;
2054        int ret;
2055
2056        spin_lock_irqsave(&tsk->sighand->siglock, flags);
2057        ret = dequeue_signal(tsk, mask, info);
2058        spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2059
2060        return ret;
2061}
2062
2063extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2064                              sigset_t *mask);
2065extern void unblock_all_signals(void);
2066extern void release_task(struct task_struct * p);
2067extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2068extern int force_sigsegv(int, struct task_struct *);
2069extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2070extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2071extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2072extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2073                                const struct cred *, u32);
2074extern int kill_pgrp(struct pid *pid, int sig, int priv);
2075extern int kill_pid(struct pid *pid, int sig, int priv);
2076extern int kill_proc_info(int, struct siginfo *, pid_t);
2077extern __must_check bool do_notify_parent(struct task_struct *, int);
2078extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2079extern void force_sig(int, struct task_struct *);
2080extern int send_sig(int, struct task_struct *, int);
2081extern int zap_other_threads(struct task_struct *p);
2082extern struct sigqueue *sigqueue_alloc(void);
2083extern void sigqueue_free(struct sigqueue *);
2084extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2085extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2086
2087static inline void restore_saved_sigmask(void)
2088{
2089        if (test_and_clear_restore_sigmask())
2090                __set_current_blocked(&current->saved_sigmask);
2091}
2092
2093static inline sigset_t *sigmask_to_save(void)
2094{
2095        sigset_t *res = &current->blocked;
2096        if (unlikely(test_restore_sigmask()))
2097                res = &current->saved_sigmask;
2098        return res;
2099}
2100
2101static inline int kill_cad_pid(int sig, int priv)
2102{
2103        return kill_pid(cad_pid, sig, priv);
2104}
2105
2106/* These can be the second arg to send_sig_info/send_group_sig_info.  */
2107#define SEND_SIG_NOINFO ((struct siginfo *) 0)
2108#define SEND_SIG_PRIV   ((struct siginfo *) 1)
2109#define SEND_SIG_FORCED ((struct siginfo *) 2)
2110
2111/*
2112 * True if we are on the alternate signal stack.
2113 */
2114static inline int on_sig_stack(unsigned long sp)
2115{
2116#ifdef CONFIG_STACK_GROWSUP
2117        return sp >= current->sas_ss_sp &&
2118                sp - current->sas_ss_sp < current->sas_ss_size;
2119#else
2120        return sp > current->sas_ss_sp &&
2121                sp - current->sas_ss_sp <= current->sas_ss_size;
2122#endif
2123}
2124
2125static inline int sas_ss_flags(unsigned long sp)
2126{
2127        return (current->sas_ss_size == 0 ? SS_DISABLE
2128                : on_sig_stack(sp) ? SS_ONSTACK : 0);
2129}
2130
2131static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2132{
2133        if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2134#ifdef CONFIG_STACK_GROWSUP
2135                return current->sas_ss_sp;
2136#else
2137                return current->sas_ss_sp + current->sas_ss_size;
2138#endif
2139        return sp;
2140}
2141
2142/*
2143 * Routines for handling mm_structs
2144 */
2145extern struct mm_struct * mm_alloc(void);
2146
2147/* mmdrop drops the mm and the page tables */
2148extern void __mmdrop(struct mm_struct *);
2149static inline void mmdrop(struct mm_struct * mm)
2150{
2151        if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2152                __mmdrop(mm);
2153}
2154
2155/* mmput gets rid of the mappings and all user-space */
2156extern void mmput(struct mm_struct *);
2157/* Grab a reference to a task's mm, if it is not already going away */
2158extern struct mm_struct *get_task_mm(struct task_struct *task);
2159/*
2160 * Grab a reference to a task's mm, if it is not already going away
2161 * and ptrace_may_access with the mode parameter passed to it
2162 * succeeds.
2163 */
2164extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2165/* Remove the current tasks stale references to the old mm_struct */
2166extern void mm_release(struct task_struct *, struct mm_struct *);
2167/* Allocate a new mm structure and copy contents from tsk->mm */
2168extern struct mm_struct *dup_mm(struct task_struct *tsk);
2169
2170extern int copy_thread(unsigned long, unsigned long, unsigned long,
2171                        struct task_struct *);
2172extern void flush_thread(void);
2173extern void exit_thread(void);
2174
2175extern void exit_files(struct task_struct *);
2176extern void __cleanup_sighand(struct sighand_struct *);
2177
2178extern void exit_itimers(struct signal_struct *);
2179extern void flush_itimer_signals(void);
2180
2181extern void do_group_exit(int);
2182
2183extern int allow_signal(int);
2184extern int disallow_signal(int);
2185
2186extern int do_execve(const char *,
2187                     const char __user * const __user *,
2188                     const char __user * const __user *);
2189extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2190struct task_struct *fork_idle(int);
2191extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2192
2193extern void set_task_comm(struct task_struct *tsk, char *from);
2194extern char *get_task_comm(char *to, struct task_struct *tsk);
2195
2196#ifdef CONFIG_SMP
2197void scheduler_ipi(void);
2198extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2199#else
2200static inline void scheduler_ipi(void) { }
2201static inline unsigned long wait_task_inactive(struct task_struct *p,
2202                                               long match_state)
2203{
2204        return 1;
2205}
2206#endif
2207
2208#define next_task(p) \
2209        list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2210
2211#define for_each_process(p) \
2212        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2213
2214extern bool current_is_single_threaded(void);
2215
2216/*
2217 * Careful: do_each_thread/while_each_thread is a double loop so
2218 *          'break' will not work as expected - use goto instead.
2219 */
2220#define do_each_thread(g, t) \
2221        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2222
2223#define while_each_thread(g, t) \
2224        while ((t = next_thread(t)) != g)
2225
2226static inline int get_nr_threads(struct task_struct *tsk)
2227{
2228        return tsk->signal->nr_threads;
2229}
2230
2231static inline bool thread_group_leader(struct task_struct *p)
2232{
2233        return p->exit_signal >= 0;
2234}
2235
2236/* Do to the insanities of de_thread it is possible for a process
2237 * to have the pid of the thread group leader without actually being
2238 * the thread group leader.  For iteration through the pids in proc
2239 * all we care about is that we have a task with the appropriate
2240 * pid, we don't actually care if we have the right task.
2241 */
2242static inline bool has_group_leader_pid(struct task_struct *p)
2243{
2244        return task_pid(p) == p->signal->leader_pid;
2245}
2246
2247static inline
2248bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2249{
2250        return p1->signal == p2->signal;
2251}
2252
2253static inline struct task_struct *next_thread(const struct task_struct *p)
2254{
2255        return list_entry_rcu(p->thread_group.next,
2256                              struct task_struct, thread_group);
2257}
2258
2259static inline int thread_group_empty(struct task_struct *p)
2260{
2261        return list_empty(&p->thread_group);
2262}
2263
2264#define delay_group_leader(p) \
2265                (thread_group_leader(p) && !thread_group_empty(p))
2266
2267/*
2268 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2269 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2270 * pins the final release of task.io_context.  Also protects ->cpuset and
2271 * ->cgroup.subsys[]. And ->vfork_done.
2272 *
2273 * Nests both inside and outside of read_lock(&tasklist_lock).
2274 * It must not be nested with write_lock_irq(&tasklist_lock),
2275 * neither inside nor outside.
2276 */
2277static inline void task_lock(struct task_struct *p)
2278{
2279        spin_lock(&p->alloc_lock);
2280}
2281
2282static inline void task_unlock(struct task_struct *p)
2283{
2284        spin_unlock(&p->alloc_lock);
2285}
2286
2287extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2288                                                        unsigned long *flags);
2289
2290static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2291                                                       unsigned long *flags)
2292{
2293        struct sighand_struct *ret;
2294
2295        ret = __lock_task_sighand(tsk, flags);
2296        (void)__cond_lock(&tsk->sighand->siglock, ret);
2297        return ret;
2298}
2299
2300static inline void unlock_task_sighand(struct task_struct *tsk,
2301                                                unsigned long *flags)
2302{
2303        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2304}
2305
2306#ifdef CONFIG_CGROUPS
2307static inline void threadgroup_change_begin(struct task_struct *tsk)
2308{
2309        down_read(&tsk->signal->group_rwsem);
2310}
2311static inline void threadgroup_change_end(struct task_struct *tsk)
2312{
2313        up_read(&tsk->signal->group_rwsem);
2314}
2315
2316/**
2317 * threadgroup_lock - lock threadgroup
2318 * @tsk: member task of the threadgroup to lock
2319 *
2320 * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2321 * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2322 * change ->group_leader/pid.  This is useful for cases where the threadgroup
2323 * needs to stay stable across blockable operations.
2324 *
2325 * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2326 * synchronization.  While held, no new task will be added to threadgroup
2327 * and no existing live task will have its PF_EXITING set.
2328 *
2329 * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2330 * sub-thread becomes a new leader.
2331 */
2332static inline void threadgroup_lock(struct task_struct *tsk)
2333{
2334        down_write(&tsk->signal->group_rwsem);
2335}
2336
2337/**
2338 * threadgroup_unlock - unlock threadgroup
2339 * @tsk: member task of the threadgroup to unlock
2340 *
2341 * Reverse threadgroup_lock().
2342 */
2343static inline void threadgroup_unlock(struct task_struct *tsk)
2344{
2345        up_write(&tsk->signal->group_rwsem);
2346}
2347#else
2348static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2349static inline void threadgroup_change_end(struct task_struct *tsk) {}
2350static inline void threadgroup_lock(struct task_struct *tsk) {}
2351static inline void threadgroup_unlock(struct task_struct *tsk) {}
2352#endif
2353
2354#ifndef __HAVE_THREAD_FUNCTIONS
2355
2356#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2357#define task_stack_page(task)   ((task)->stack)
2358
2359static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2360{
2361        *task_thread_info(p) = *task_thread_info(org);
2362        task_thread_info(p)->task = p;
2363}
2364
2365static inline unsigned long *end_of_stack(struct task_struct *p)
2366{
2367        return (unsigned long *)(task_thread_info(p) + 1);
2368}
2369
2370#endif
2371
2372static inline int object_is_on_stack(void *obj)
2373{
2374        void *stack = task_stack_page(current);
2375
2376        return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2377}
2378
2379extern void thread_info_cache_init(void);
2380
2381#ifdef CONFIG_DEBUG_STACK_USAGE
2382static inline unsigned long stack_not_used(struct task_struct *p)
2383{
2384        unsigned long *n = end_of_stack(p);
2385
2386        do {    /* Skip over canary */
2387                n++;
2388        } while (!*n);
2389
2390        return (unsigned long)n - (unsigned long)end_of_stack(p);
2391}
2392#endif
2393
2394/* set thread flags in other task's structures
2395 * - see asm/thread_info.h for TIF_xxxx flags available
2396 */
2397static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2398{
2399        set_ti_thread_flag(task_thread_info(tsk), flag);
2400}
2401
2402static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2403{
2404        clear_ti_thread_flag(task_thread_info(tsk), flag);
2405}
2406
2407static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2408{
2409        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2410}
2411
2412static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2413{
2414        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2415}
2416
2417static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2418{
2419        return test_ti_thread_flag(task_thread_info(tsk), flag);
2420}
2421
2422static inline void set_tsk_need_resched(struct task_struct *tsk)
2423{
2424        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2425}
2426
2427static inline void clear_tsk_need_resched(struct task_struct *tsk)
2428{
2429        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2430}
2431
2432static inline int test_tsk_need_resched(struct task_struct *tsk)
2433{
2434        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2435}
2436
2437static inline int restart_syscall(void)
2438{
2439        set_tsk_thread_flag(current, TIF_SIGPENDING);
2440        return -ERESTARTNOINTR;
2441}
2442
2443static inline int signal_pending(struct task_struct *p)
2444{
2445        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2446}
2447
2448static inline int __fatal_signal_pending(struct task_struct *p)
2449{
2450        return unlikely(sigismember(&p->pending.signal, SIGKILL));
2451}
2452
2453static inline int fatal_signal_pending(struct task_struct *p)
2454{
2455        return signal_pending(p) && __fatal_signal_pending(p);
2456}
2457
2458static inline int signal_pending_state(long state, struct task_struct *p)
2459{
2460        if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2461                return 0;
2462        if (!signal_pending(p))
2463                return 0;
2464
2465        return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2466}
2467
2468/*
2469 * cond_resched() and cond_resched_lock(): latency reduction via
2470 * explicit rescheduling in places that are safe. The return
2471 * value indicates whether a reschedule was done in fact.
2472 * cond_resched_lock() will drop the spinlock before scheduling,
2473 * cond_resched_softirq() will enable bhs before scheduling.
2474 */
2475extern int _cond_resched(void);
2476
2477#define cond_resched() ({                       \
2478        __might_sleep(__FILE__, __LINE__, 0);   \
2479        _cond_resched();                        \
2480})
2481
2482extern int __cond_resched_lock(spinlock_t *lock);
2483
2484#ifdef CONFIG_PREEMPT_COUNT
2485#define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2486#else
2487#define PREEMPT_LOCK_OFFSET     0
2488#endif
2489
2490#define cond_resched_lock(lock) ({                              \
2491        __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2492        __cond_resched_lock(lock);                              \
2493})
2494
2495extern int __cond_resched_softirq(void);
2496
2497#define cond_resched_softirq() ({                                       \
2498        __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);      \
2499        __cond_resched_softirq();                                       \
2500})
2501
2502static inline void cond_resched_rcu(void)
2503{
2504#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2505        rcu_read_unlock();
2506        cond_resched();
2507        rcu_read_lock();
2508#endif
2509}
2510
2511/*
2512 * Does a critical section need to be broken due to another
2513 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2514 * but a general need for low latency)
2515 */
2516static inline int spin_needbreak(spinlock_t *lock)
2517{
2518#ifdef CONFIG_PREEMPT
2519        return spin_is_contended(lock);
2520#else
2521        return 0;
2522#endif
2523}
2524
2525/*
2526 * Idle thread specific functions to determine the need_resched
2527 * polling state. We have two versions, one based on TS_POLLING in
2528 * thread_info.status and one based on TIF_POLLING_NRFLAG in
2529 * thread_info.flags
2530 */
2531#ifdef TS_POLLING
2532static inline int tsk_is_polling(struct task_struct *p)
2533{
2534        return task_thread_info(p)->status & TS_POLLING;
2535}
2536static inline void __current_set_polling(void)
2537{
2538        current_thread_info()->status |= TS_POLLING;
2539}
2540
2541static inline bool __must_check current_set_polling_and_test(void)
2542{
2543        __current_set_polling();
2544
2545        /*
2546         * Polling state must be visible before we test NEED_RESCHED,
2547         * paired by resched_task()
2548         */
2549        smp_mb();
2550
2551        return unlikely(tif_need_resched());
2552}
2553
2554static inline void __current_clr_polling(void)
2555{
2556        current_thread_info()->status &= ~TS_POLLING;
2557}
2558
2559static inline bool __must_check current_clr_polling_and_test(void)
2560{
2561        __current_clr_polling();
2562
2563        /*
2564         * Polling state must be visible before we test NEED_RESCHED,
2565         * paired by resched_task()
2566         */
2567        smp_mb();
2568
2569        return unlikely(tif_need_resched());
2570}
2571#elif defined(TIF_POLLING_NRFLAG)
2572static inline int tsk_is_polling(struct task_struct *p)
2573{
2574        return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2575}
2576
2577static inline void __current_set_polling(void)
2578{
2579        set_thread_flag(TIF_POLLING_NRFLAG);
2580}
2581
2582static inline bool __must_check current_set_polling_and_test(void)
2583{
2584        __current_set_polling();
2585
2586        /*
2587         * Polling state must be visible before we test NEED_RESCHED,
2588         * paired by resched_task()
2589         *
2590         * XXX: assumes set/clear bit are identical barrier wise.
2591         */
2592        smp_mb__after_clear_bit();
2593
2594        return unlikely(tif_need_resched());
2595}
2596
2597static inline void __current_clr_polling(void)
2598{
2599        clear_thread_flag(TIF_POLLING_NRFLAG);
2600}
2601
2602static inline bool __must_check current_clr_polling_and_test(void)
2603{
2604        __current_clr_polling();
2605
2606        /*
2607         * Polling state must be visible before we test NEED_RESCHED,
2608         * paired by resched_task()
2609         */
2610        smp_mb__after_clear_bit();
2611
2612        return unlikely(tif_need_resched());
2613}
2614
2615#else
2616static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2617static inline void __current_set_polling(void) { }
2618static inline void __current_clr_polling(void) { }
2619
2620static inline bool __must_check current_set_polling_and_test(void)
2621{
2622        return unlikely(tif_need_resched());
2623}
2624static inline bool __must_check current_clr_polling_and_test(void)
2625{
2626        return unlikely(tif_need_resched());
2627}
2628#endif
2629
2630static __always_inline bool need_resched(void)
2631{
2632        return unlikely(tif_need_resched());
2633}
2634
2635/*
2636 * Thread group CPU time accounting.
2637 */
2638void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2639void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2640
2641static inline void thread_group_cputime_init(struct signal_struct *sig)
2642{
2643        raw_spin_lock_init(&sig->cputimer.lock);
2644}
2645
2646/*
2647 * Reevaluate whether the task has signals pending delivery.
2648 * Wake the task if so.
2649 * This is required every time the blocked sigset_t changes.
2650 * callers must hold sighand->siglock.
2651 */
2652extern void recalc_sigpending_and_wake(struct task_struct *t);
2653extern void recalc_sigpending(void);
2654
2655extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2656
2657static inline void signal_wake_up(struct task_struct *t, bool resume)
2658{
2659        signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2660}
2661static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2662{
2663        signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2664}
2665
2666/*
2667 * Wrappers for p->thread_info->cpu access. No-op on UP.
2668 */
2669#ifdef CONFIG_SMP
2670
2671static inline unsigned int task_cpu(const struct task_struct *p)
2672{
2673        return task_thread_info(p)->cpu;
2674}
2675
2676static inline int task_node(const struct task_struct *p)
2677{
2678        return cpu_to_node(task_cpu(p));
2679}
2680
2681extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2682
2683#else
2684
2685static inline unsigned int task_cpu(const struct task_struct *p)
2686{
2687        return 0;
2688}
2689
2690static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2691{
2692}
2693
2694#endif /* CONFIG_SMP */
2695
2696extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2697extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2698
2699#ifdef CONFIG_CGROUP_SCHED
2700extern struct task_group root_task_group;
2701#endif /* CONFIG_CGROUP_SCHED */
2702
2703extern int task_can_switch_user(struct user_struct *up,
2704                                        struct task_struct *tsk);
2705
2706#ifdef CONFIG_TASK_XACCT
2707static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2708{
2709        tsk->ioac.rchar += amt;
2710}
2711
2712static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2713{
2714        tsk->ioac.wchar += amt;
2715}
2716
2717static inline void inc_syscr(struct task_struct *tsk)
2718{
2719        tsk->ioac.syscr++;
2720}
2721
2722static inline void inc_syscw(struct task_struct *tsk)
2723{
2724        tsk->ioac.syscw++;
2725}
2726#else
2727static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2728{
2729}
2730
2731static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2732{
2733}
2734
2735static inline void inc_syscr(struct task_struct *tsk)
2736{
2737}
2738
2739static inline void inc_syscw(struct task_struct *tsk)
2740{
2741}
2742#endif
2743
2744#ifndef TASK_SIZE_OF
2745#define TASK_SIZE_OF(tsk)       TASK_SIZE
2746#endif
2747
2748#ifdef CONFIG_MM_OWNER
2749extern void mm_update_next_owner(struct mm_struct *mm);
2750extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2751#else
2752static inline void mm_update_next_owner(struct mm_struct *mm)
2753{
2754}
2755
2756static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2757{
2758}
2759#endif /* CONFIG_MM_OWNER */
2760
2761static inline unsigned long task_rlimit(const struct task_struct *tsk,
2762                unsigned int limit)
2763{
2764        return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2765}
2766
2767static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2768                unsigned int limit)
2769{
2770        return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2771}
2772
2773static inline unsigned long rlimit(unsigned int limit)
2774{
2775        return task_rlimit(current, limit);
2776}
2777
2778static inline unsigned long rlimit_max(unsigned int limit)
2779{
2780        return task_rlimit_max(current, limit);
2781}
2782
2783#endif
2784
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