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#include <linux/sched/prio.h>
   7
   8
   9struct sched_param {
  10        int sched_priority;
  11};
  12
  13#include <asm/param.h>  /* for HZ */
  14
  15#include <linux/capability.h>
  16#include <linux/threads.h>
  17#include <linux/kernel.h>
  18#include <linux/types.h>
  19#include <linux/timex.h>
  20#include <linux/jiffies.h>
  21#include <linux/plist.h>
  22#include <linux/rbtree.h>
  23#include <linux/thread_info.h>
  24#include <linux/cpumask.h>
  25#include <linux/errno.h>
  26#include <linux/nodemask.h>
  27#include <linux/mm_types.h>
  28#include <linux/preempt.h>
  29
  30#include <asm/page.h>
  31#include <asm/ptrace.h>
  32#include <linux/cputime.h>
  33
  34#include <linux/smp.h>
  35#include <linux/sem.h>
  36#include <linux/shm.h>
  37#include <linux/signal.h>
  38#include <linux/compiler.h>
  39#include <linux/completion.h>
  40#include <linux/pid.h>
  41#include <linux/percpu.h>
  42#include <linux/topology.h>
  43#include <linux/seccomp.h>
  44#include <linux/rcupdate.h>
  45#include <linux/rculist.h>
  46#include <linux/rtmutex.h>
  47
  48#include <linux/time.h>
  49#include <linux/param.h>
  50#include <linux/resource.h>
  51#include <linux/timer.h>
  52#include <linux/hrtimer.h>
  53#include <linux/kcov.h>
  54#include <linux/task_io_accounting.h>
  55#include <linux/latencytop.h>
  56#include <linux/cred.h>
  57#include <linux/llist.h>
  58#include <linux/uidgid.h>
  59#include <linux/gfp.h>
  60#include <linux/magic.h>
  61#include <linux/cgroup-defs.h>
  62
  63#include <asm/processor.h>
  64
  65#define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
  66
  67/*
  68 * Extended scheduling parameters data structure.
  69 *
  70 * This is needed because the original struct sched_param can not be
  71 * altered without introducing ABI issues with legacy applications
  72 * (e.g., in sched_getparam()).
  73 *
  74 * However, the possibility of specifying more than just a priority for
  75 * the tasks may be useful for a wide variety of application fields, e.g.,
  76 * multimedia, streaming, automation and control, and many others.
  77 *
  78 * This variant (sched_attr) is meant at describing a so-called
  79 * sporadic time-constrained task. In such model a task is specified by:
  80 *  - the activation period or minimum instance inter-arrival time;
  81 *  - the maximum (or average, depending on the actual scheduling
  82 *    discipline) computation time of all instances, a.k.a. runtime;
  83 *  - the deadline (relative to the actual activation time) of each
  84 *    instance.
  85 * Very briefly, a periodic (sporadic) task asks for the execution of
  86 * some specific computation --which is typically called an instance--
  87 * (at most) every period. Moreover, each instance typically lasts no more
  88 * than the runtime and must be completed by time instant t equal to
  89 * the instance activation time + the deadline.
  90 *
  91 * This is reflected by the actual fields of the sched_attr structure:
  92 *
  93 *  @size               size of the structure, for fwd/bwd compat.
  94 *
  95 *  @sched_policy       task's scheduling policy
  96 *  @sched_flags        for customizing the scheduler behaviour
  97 *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
  98 *  @sched_priority     task's static priority (SCHED_FIFO/RR)
  99 *  @sched_deadline     representative of the task's deadline
 100 *  @sched_runtime      representative of the task's runtime
 101 *  @sched_period       representative of the task's period
 102 *
 103 * Given this task model, there are a multiplicity of scheduling algorithms
 104 * and policies, that can be used to ensure all the tasks will make their
 105 * timing constraints.
 106 *
 107 * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
 108 * only user of this new interface. More information about the algorithm
 109 * available in the scheduling class file or in Documentation/.
 110 */
 111struct sched_attr {
 112        u32 size;
 113
 114        u32 sched_policy;
 115        u64 sched_flags;
 116
 117        /* SCHED_NORMAL, SCHED_BATCH */
 118        s32 sched_nice;
 119
 120        /* SCHED_FIFO, SCHED_RR */
 121        u32 sched_priority;
 122
 123        /* SCHED_DEADLINE */
 124        u64 sched_runtime;
 125        u64 sched_deadline;
 126        u64 sched_period;
 127};
 128
 129struct futex_pi_state;
 130struct robust_list_head;
 131struct bio_list;
 132struct fs_struct;
 133struct perf_event_context;
 134struct blk_plug;
 135struct filename;
 136struct nameidata;
 137
 138#define VMACACHE_BITS 2
 139#define VMACACHE_SIZE (1U << VMACACHE_BITS)
 140#define VMACACHE_MASK (VMACACHE_SIZE - 1)
 141
 142/*
 143 * These are the constant used to fake the fixed-point load-average
 144 * counting. Some notes:
 145 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 146 *    a load-average precision of 10 bits integer + 11 bits fractional
 147 *  - if you want to count load-averages more often, you need more
 148 *    precision, or rounding will get you. With 2-second counting freq,
 149 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 150 *    11 bit fractions.
 151 */
 152extern unsigned long avenrun[];         /* Load averages */
 153extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
 154
 155#define FSHIFT          11              /* nr of bits of precision */
 156#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 157#define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
 158#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 159#define EXP_5           2014            /* 1/exp(5sec/5min) */
 160#define EXP_15          2037            /* 1/exp(5sec/15min) */
 161
 162#define CALC_LOAD(load,exp,n) \
 163        load *= exp; \
 164        load += n*(FIXED_1-exp); \
 165        load >>= FSHIFT;
 166
 167extern unsigned long total_forks;
 168extern int nr_threads;
 169DECLARE_PER_CPU(unsigned long, process_counts);
 170extern int nr_processes(void);
 171extern unsigned long nr_running(void);
 172extern bool single_task_running(void);
 173extern unsigned long nr_iowait(void);
 174extern unsigned long nr_iowait_cpu(int cpu);
 175extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
 176
 177extern void calc_global_load(unsigned long ticks);
 178
 179#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 180extern void cpu_load_update_nohz_start(void);
 181extern void cpu_load_update_nohz_stop(void);
 182#else
 183static inline void cpu_load_update_nohz_start(void) { }
 184static inline void cpu_load_update_nohz_stop(void) { }
 185#endif
 186
 187extern void dump_cpu_task(int cpu);
 188
 189struct seq_file;
 190struct cfs_rq;
 191struct task_group;
 192#ifdef CONFIG_SCHED_DEBUG
 193extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
 194extern void proc_sched_set_task(struct task_struct *p);
 195#endif
 196
 197/*
 198 * Task state bitmask. NOTE! These bits are also
 199 * encoded in fs/proc/array.c: get_task_state().
 200 *
 201 * We have two separate sets of flags: task->state
 202 * is about runnability, while task->exit_state are
 203 * about the task exiting. Confusing, but this way
 204 * modifying one set can't modify the other one by
 205 * mistake.
 206 */
 207#define TASK_RUNNING            0
 208#define TASK_INTERRUPTIBLE      1
 209#define TASK_UNINTERRUPTIBLE    2
 210#define __TASK_STOPPED          4
 211#define __TASK_TRACED           8
 212/* in tsk->exit_state */
 213#define EXIT_DEAD               16
 214#define EXIT_ZOMBIE             32
 215#define EXIT_TRACE              (EXIT_ZOMBIE | EXIT_DEAD)
 216/* in tsk->state again */
 217#define TASK_DEAD               64
 218#define TASK_WAKEKILL           128
 219#define TASK_WAKING             256
 220#define TASK_PARKED             512
 221#define TASK_NOLOAD             1024
 222#define TASK_STATE_MAX          2048
 223
 224#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN"
 225
 226extern char ___assert_task_state[1 - 2*!!(
 227                sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
 228
 229/* Convenience macros for the sake of set_task_state */
 230#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 231#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
 232#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 233
 234#define TASK_IDLE               (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 235
 236/* Convenience macros for the sake of wake_up */
 237#define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 238#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 239
 240/* get_task_state() */
 241#define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 242                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 243                                 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
 244
 245#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
 246#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 247#define task_is_stopped_or_traced(task) \
 248                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 249#define task_contributes_to_load(task)  \
 250                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 251                                 (task->flags & PF_FROZEN) == 0 && \
 252                                 (task->state & TASK_NOLOAD) == 0)
 253
 254#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 255
 256#define __set_task_state(tsk, state_value)                      \
 257        do {                                                    \
 258                (tsk)->task_state_change = _THIS_IP_;           \
 259                (tsk)->state = (state_value);                   \
 260        } while (0)
 261#define set_task_state(tsk, state_value)                        \
 262        do {                                                    \
 263                (tsk)->task_state_change = _THIS_IP_;           \
 264                smp_store_mb((tsk)->state, (state_value));              \
 265        } while (0)
 266
 267/*
 268 * set_current_state() includes a barrier so that the write of current->state
 269 * is correctly serialised wrt the caller's subsequent test of whether to
 270 * actually sleep:
 271 *
 272 *      set_current_state(TASK_UNINTERRUPTIBLE);
 273 *      if (do_i_need_to_sleep())
 274 *              schedule();
 275 *
 276 * If the caller does not need such serialisation then use __set_current_state()
 277 */
 278#define __set_current_state(state_value)                        \
 279        do {                                                    \
 280                current->task_state_change = _THIS_IP_;         \
 281                current->state = (state_value);                 \
 282        } while (0)
 283#define set_current_state(state_value)                          \
 284        do {                                                    \
 285                current->task_state_change = _THIS_IP_;         \
 286                smp_store_mb(current->state, (state_value));            \
 287        } while (0)
 288
 289#else
 290
 291#define __set_task_state(tsk, state_value)              \
 292        do { (tsk)->state = (state_value); } while (0)
 293#define set_task_state(tsk, state_value)                \
 294        smp_store_mb((tsk)->state, (state_value))
 295
 296/*
 297 * set_current_state() includes a barrier so that the write of current->state
 298 * is correctly serialised wrt the caller's subsequent test of whether to
 299 * actually sleep:
 300 *
 301 *      set_current_state(TASK_UNINTERRUPTIBLE);
 302 *      if (do_i_need_to_sleep())
 303 *              schedule();
 304 *
 305 * If the caller does not need such serialisation then use __set_current_state()
 306 */
 307#define __set_current_state(state_value)                \
 308        do { current->state = (state_value); } while (0)
 309#define set_current_state(state_value)                  \
 310        smp_store_mb(current->state, (state_value))
 311
 312#endif
 313
 314/* Task command name length */
 315#define TASK_COMM_LEN 16
 316
 317#include <linux/spinlock.h>
 318
 319/*
 320 * This serializes "schedule()" and also protects
 321 * the run-queue from deletions/modifications (but
 322 * _adding_ to the beginning of the run-queue has
 323 * a separate lock).
 324 */
 325extern rwlock_t tasklist_lock;
 326extern spinlock_t mmlist_lock;
 327
 328struct task_struct;
 329
 330#ifdef CONFIG_PROVE_RCU
 331extern int lockdep_tasklist_lock_is_held(void);
 332#endif /* #ifdef CONFIG_PROVE_RCU */
 333
 334extern void sched_init(void);
 335extern void sched_init_smp(void);
 336extern asmlinkage void schedule_tail(struct task_struct *prev);
 337extern void init_idle(struct task_struct *idle, int cpu);
 338extern void init_idle_bootup_task(struct task_struct *idle);
 339
 340extern cpumask_var_t cpu_isolated_map;
 341
 342extern int runqueue_is_locked(int cpu);
 343
 344#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 345extern void nohz_balance_enter_idle(int cpu);
 346extern void set_cpu_sd_state_idle(void);
 347extern int get_nohz_timer_target(void);
 348#else
 349static inline void nohz_balance_enter_idle(int cpu) { }
 350static inline void set_cpu_sd_state_idle(void) { }
 351#endif
 352
 353/*
 354 * Only dump TASK_* tasks. (0 for all tasks)
 355 */
 356extern void show_state_filter(unsigned long state_filter);
 357
 358static inline void show_state(void)
 359{
 360        show_state_filter(0);
 361}
 362
 363extern void show_regs(struct pt_regs *);
 364
 365/*
 366 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 367 * task), SP is the stack pointer of the first frame that should be shown in the back
 368 * trace (or NULL if the entire call-chain of the task should be shown).
 369 */
 370extern void show_stack(struct task_struct *task, unsigned long *sp);
 371
 372extern void cpu_init (void);
 373extern void trap_init(void);
 374extern void update_process_times(int user);
 375extern void scheduler_tick(void);
 376extern int sched_cpu_starting(unsigned int cpu);
 377extern int sched_cpu_activate(unsigned int cpu);
 378extern int sched_cpu_deactivate(unsigned int cpu);
 379
 380#ifdef CONFIG_HOTPLUG_CPU
 381extern int sched_cpu_dying(unsigned int cpu);
 382#else
 383# define sched_cpu_dying        NULL
 384#endif
 385
 386extern void sched_show_task(struct task_struct *p);
 387
 388#ifdef CONFIG_LOCKUP_DETECTOR
 389extern void touch_softlockup_watchdog_sched(void);
 390extern void touch_softlockup_watchdog(void);
 391extern void touch_softlockup_watchdog_sync(void);
 392extern void touch_all_softlockup_watchdogs(void);
 393extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
 394                                  void __user *buffer,
 395                                  size_t *lenp, loff_t *ppos);
 396extern unsigned int  softlockup_panic;
 397extern unsigned int  hardlockup_panic;
 398void lockup_detector_init(void);
 399#else
 400static inline void touch_softlockup_watchdog_sched(void)
 401{
 402}
 403static inline void touch_softlockup_watchdog(void)
 404{
 405}
 406static inline void touch_softlockup_watchdog_sync(void)
 407{
 408}
 409static inline void touch_all_softlockup_watchdogs(void)
 410{
 411}
 412static inline void lockup_detector_init(void)
 413{
 414}
 415#endif
 416
 417#ifdef CONFIG_DETECT_HUNG_TASK
 418void reset_hung_task_detector(void);
 419#else
 420static inline void reset_hung_task_detector(void)
 421{
 422}
 423#endif
 424
 425/* Attach to any functions which should be ignored in wchan output. */
 426#define __sched         __attribute__((__section__(".sched.text")))
 427
 428/* Linker adds these: start and end of __sched functions */
 429extern char __sched_text_start[], __sched_text_end[];
 430
 431/* Is this address in the __sched functions? */
 432extern int in_sched_functions(unsigned long addr);
 433
 434#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 435extern signed long schedule_timeout(signed long timeout);
 436extern signed long schedule_timeout_interruptible(signed long timeout);
 437extern signed long schedule_timeout_killable(signed long timeout);
 438extern signed long schedule_timeout_uninterruptible(signed long timeout);
 439extern signed long schedule_timeout_idle(signed long timeout);
 440asmlinkage void schedule(void);
 441extern void schedule_preempt_disabled(void);
 442
 443extern long io_schedule_timeout(long timeout);
 444
 445static inline void io_schedule(void)
 446{
 447        io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
 448}
 449
 450struct nsproxy;
 451struct user_namespace;
 452
 453#ifdef CONFIG_MMU
 454extern void arch_pick_mmap_layout(struct mm_struct *mm);
 455extern unsigned long
 456arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 457                       unsigned long, unsigned long);
 458extern unsigned long
 459arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 460                          unsigned long len, unsigned long pgoff,
 461                          unsigned long flags);
 462#else
 463static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
 464#endif
 465
 466#define SUID_DUMP_DISABLE       0       /* No setuid dumping */
 467#define SUID_DUMP_USER          1       /* Dump as user of process */
 468#define SUID_DUMP_ROOT          2       /* Dump as root */
 469
 470/* mm flags */
 471
 472/* for SUID_DUMP_* above */
 473#define MMF_DUMPABLE_BITS 2
 474#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
 475
 476extern void set_dumpable(struct mm_struct *mm, int value);
 477/*
 478 * This returns the actual value of the suid_dumpable flag. For things
 479 * that are using this for checking for privilege transitions, it must
 480 * test against SUID_DUMP_USER rather than treating it as a boolean
 481 * value.
 482 */
 483static inline int __get_dumpable(unsigned long mm_flags)
 484{
 485        return mm_flags & MMF_DUMPABLE_MASK;
 486}
 487
 488static inline int get_dumpable(struct mm_struct *mm)
 489{
 490        return __get_dumpable(mm->flags);
 491}
 492
 493/* coredump filter bits */
 494#define MMF_DUMP_ANON_PRIVATE   2
 495#define MMF_DUMP_ANON_SHARED    3
 496#define MMF_DUMP_MAPPED_PRIVATE 4
 497#define MMF_DUMP_MAPPED_SHARED  5
 498#define MMF_DUMP_ELF_HEADERS    6
 499#define MMF_DUMP_HUGETLB_PRIVATE 7
 500#define MMF_DUMP_HUGETLB_SHARED  8
 501#define MMF_DUMP_DAX_PRIVATE    9
 502#define MMF_DUMP_DAX_SHARED     10
 503
 504#define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
 505#define MMF_DUMP_FILTER_BITS    9
 506#define MMF_DUMP_FILTER_MASK \
 507        (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 508#define MMF_DUMP_FILTER_DEFAULT \
 509        ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
 510         (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
 511
 512#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
 513# define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
 514#else
 515# define MMF_DUMP_MASK_DEFAULT_ELF      0
 516#endif
 517                                        /* leave room for more dump flags */
 518#define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
 519#define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
 520#define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
 521
 522#define MMF_HAS_UPROBES         19      /* has uprobes */
 523#define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
 524#define MMF_OOM_REAPED          21      /* mm has been already reaped */
 525
 526#define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
 527
 528struct sighand_struct {
 529        atomic_t                count;
 530        struct k_sigaction      action[_NSIG];
 531        spinlock_t              siglock;
 532        wait_queue_head_t       signalfd_wqh;
 533};
 534
 535struct pacct_struct {
 536        int                     ac_flag;
 537        long                    ac_exitcode;
 538        unsigned long           ac_mem;
 539        cputime_t               ac_utime, ac_stime;
 540        unsigned long           ac_minflt, ac_majflt;
 541};
 542
 543struct cpu_itimer {
 544        cputime_t expires;
 545        cputime_t incr;
 546        u32 error;
 547        u32 incr_error;
 548};
 549
 550/**
 551 * struct prev_cputime - snaphsot of system and user cputime
 552 * @utime: time spent in user mode
 553 * @stime: time spent in system mode
 554 * @lock: protects the above two fields
 555 *
 556 * Stores previous user/system time values such that we can guarantee
 557 * monotonicity.
 558 */
 559struct prev_cputime {
 560#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 561        cputime_t utime;
 562        cputime_t stime;
 563        raw_spinlock_t lock;
 564#endif
 565};
 566
 567static inline void prev_cputime_init(struct prev_cputime *prev)
 568{
 569#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 570        prev->utime = prev->stime = 0;
 571        raw_spin_lock_init(&prev->lock);
 572#endif
 573}
 574
 575/**
 576 * struct task_cputime - collected CPU time counts
 577 * @utime:              time spent in user mode, in &cputime_t units
 578 * @stime:              time spent in kernel mode, in &cputime_t units
 579 * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
 580 *
 581 * This structure groups together three kinds of CPU time that are tracked for
 582 * threads and thread groups.  Most things considering CPU time want to group
 583 * these counts together and treat all three of them in parallel.
 584 */
 585struct task_cputime {
 586        cputime_t utime;
 587        cputime_t stime;
 588        unsigned long long sum_exec_runtime;
 589};
 590
 591/* Alternate field names when used to cache expirations. */
 592#define virt_exp        utime
 593#define prof_exp        stime
 594#define sched_exp       sum_exec_runtime
 595
 596#define INIT_CPUTIME    \
 597        (struct task_cputime) {                                 \
 598                .utime = 0,                                     \
 599                .stime = 0,                                     \
 600                .sum_exec_runtime = 0,                          \
 601        }
 602
 603/*
 604 * This is the atomic variant of task_cputime, which can be used for
 605 * storing and updating task_cputime statistics without locking.
 606 */
 607struct task_cputime_atomic {
 608        atomic64_t utime;
 609        atomic64_t stime;
 610        atomic64_t sum_exec_runtime;
 611};
 612
 613#define INIT_CPUTIME_ATOMIC \
 614        (struct task_cputime_atomic) {                          \
 615                .utime = ATOMIC64_INIT(0),                      \
 616                .stime = ATOMIC64_INIT(0),                      \
 617                .sum_exec_runtime = ATOMIC64_INIT(0),           \
 618        }
 619
 620#define PREEMPT_DISABLED        (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
 621
 622/*
 623 * Disable preemption until the scheduler is running -- use an unconditional
 624 * value so that it also works on !PREEMPT_COUNT kernels.
 625 *
 626 * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
 627 */
 628#define INIT_PREEMPT_COUNT      PREEMPT_OFFSET
 629
 630/*
 631 * Initial preempt_count value; reflects the preempt_count schedule invariant
 632 * which states that during context switches:
 633 *
 634 *    preempt_count() == 2*PREEMPT_DISABLE_OFFSET
 635 *
 636 * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
 637 * Note: See finish_task_switch().
 638 */
 639#define FORK_PREEMPT_COUNT      (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
 640
 641/**
 642 * struct thread_group_cputimer - thread group interval timer counts
 643 * @cputime_atomic:     atomic thread group interval timers.
 644 * @running:            true when there are timers running and
 645 *                      @cputime_atomic receives updates.
 646 * @checking_timer:     true when a thread in the group is in the
 647 *                      process of checking for thread group timers.
 648 *
 649 * This structure contains the version of task_cputime, above, that is
 650 * used for thread group CPU timer calculations.
 651 */
 652struct thread_group_cputimer {
 653        struct task_cputime_atomic cputime_atomic;
 654        bool running;
 655        bool checking_timer;
 656};
 657
 658#include <linux/rwsem.h>
 659struct autogroup;
 660
 661/*
 662 * NOTE! "signal_struct" does not have its own
 663 * locking, because a shared signal_struct always
 664 * implies a shared sighand_struct, so locking
 665 * sighand_struct is always a proper superset of
 666 * the locking of signal_struct.
 667 */
 668struct signal_struct {
 669        atomic_t                sigcnt;
 670        atomic_t                live;
 671        int                     nr_threads;
 672        atomic_t oom_victims; /* # of TIF_MEDIE threads in this thread group */
 673        struct list_head        thread_head;
 674
 675        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 676
 677        /* current thread group signal load-balancing target: */
 678        struct task_struct      *curr_target;
 679
 680        /* shared signal handling: */
 681        struct sigpending       shared_pending;
 682
 683        /* thread group exit support */
 684        int                     group_exit_code;
 685        /* overloaded:
 686         * - notify group_exit_task when ->count is equal to notify_count
 687         * - everyone except group_exit_task is stopped during signal delivery
 688         *   of fatal signals, group_exit_task processes the signal.
 689         */
 690        int                     notify_count;
 691        struct task_struct      *group_exit_task;
 692
 693        /* thread group stop support, overloads group_exit_code too */
 694        int                     group_stop_count;
 695        unsigned int            flags; /* see SIGNAL_* flags below */
 696
 697        /*
 698         * PR_SET_CHILD_SUBREAPER marks a process, like a service
 699         * manager, to re-parent orphan (double-forking) child processes
 700         * to this process instead of 'init'. The service manager is
 701         * able to receive SIGCHLD signals and is able to investigate
 702         * the process until it calls wait(). All children of this
 703         * process will inherit a flag if they should look for a
 704         * child_subreaper process at exit.
 705         */
 706        unsigned int            is_child_subreaper:1;
 707        unsigned int            has_child_subreaper:1;
 708
 709        /* POSIX.1b Interval Timers */
 710        int                     posix_timer_id;
 711        struct list_head        posix_timers;
 712
 713        /* ITIMER_REAL timer for the process */
 714        struct hrtimer real_timer;
 715        struct pid *leader_pid;
 716        ktime_t it_real_incr;
 717
 718        /*
 719         * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
 720         * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
 721         * values are defined to 0 and 1 respectively
 722         */
 723        struct cpu_itimer it[2];
 724
 725        /*
 726         * Thread group totals for process CPU timers.
 727         * See thread_group_cputimer(), et al, for details.
 728         */
 729        struct thread_group_cputimer cputimer;
 730
 731        /* Earliest-expiration cache. */
 732        struct task_cputime cputime_expires;
 733
 734#ifdef CONFIG_NO_HZ_FULL
 735        atomic_t tick_dep_mask;
 736#endif
 737
 738        struct list_head cpu_timers[3];
 739
 740        struct pid *tty_old_pgrp;
 741
 742        /* boolean value for session group leader */
 743        int leader;
 744
 745        struct tty_struct *tty; /* NULL if no tty */
 746
 747#ifdef CONFIG_SCHED_AUTOGROUP
 748        struct autogroup *autogroup;
 749#endif
 750        /*
 751         * Cumulative resource counters for dead threads in the group,
 752         * and for reaped dead child processes forked by this group.
 753         * Live threads maintain their own counters and add to these
 754         * in __exit_signal, except for the group leader.
 755         */
 756        seqlock_t stats_lock;
 757        cputime_t utime, stime, cutime, cstime;
 758        cputime_t gtime;
 759        cputime_t cgtime;
 760        struct prev_cputime prev_cputime;
 761        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 762        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 763        unsigned long inblock, oublock, cinblock, coublock;
 764        unsigned long maxrss, cmaxrss;
 765        struct task_io_accounting ioac;
 766
 767        /*
 768         * Cumulative ns of schedule CPU time fo dead threads in the
 769         * group, not including a zombie group leader, (This only differs
 770         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 771         * other than jiffies.)
 772         */
 773        unsigned long long sum_sched_runtime;
 774
 775        /*
 776         * We don't bother to synchronize most readers of this at all,
 777         * because there is no reader checking a limit that actually needs
 778         * to get both rlim_cur and rlim_max atomically, and either one
 779         * alone is a single word that can safely be read normally.
 780         * getrlimit/setrlimit use task_lock(current->group_leader) to
 781         * protect this instead of the siglock, because they really
 782         * have no need to disable irqs.
 783         */
 784        struct rlimit rlim[RLIM_NLIMITS];
 785
 786#ifdef CONFIG_BSD_PROCESS_ACCT
 787        struct pacct_struct pacct;      /* per-process accounting information */
 788#endif
 789#ifdef CONFIG_TASKSTATS
 790        struct taskstats *stats;
 791#endif
 792#ifdef CONFIG_AUDIT
 793        unsigned audit_tty;
 794        struct tty_audit_buf *tty_audit_buf;
 795#endif
 796
 797        /*
 798         * Thread is the potential origin of an oom condition; kill first on
 799         * oom
 800         */
 801        bool oom_flag_origin;
 802        short oom_score_adj;            /* OOM kill score adjustment */
 803        short oom_score_adj_min;        /* OOM kill score adjustment min value.
 804                                         * Only settable by CAP_SYS_RESOURCE. */
 805
 806        struct mutex cred_guard_mutex;  /* guard against foreign influences on
 807                                         * credential calculations
 808                                         * (notably. ptrace) */
 809};
 810
 811/*
 812 * Bits in flags field of signal_struct.
 813 */
 814#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 815#define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
 816#define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
 817#define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
 818/*
 819 * Pending notifications to parent.
 820 */
 821#define SIGNAL_CLD_STOPPED      0x00000010
 822#define SIGNAL_CLD_CONTINUED    0x00000020
 823#define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
 824
 825#define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
 826
 827/* If true, all threads except ->group_exit_task have pending SIGKILL */
 828static inline int signal_group_exit(const struct signal_struct *sig)
 829{
 830        return  (sig->flags & SIGNAL_GROUP_EXIT) ||
 831                (sig->group_exit_task != NULL);
 832}
 833
 834/*
 835 * Some day this will be a full-fledged user tracking system..
 836 */
 837struct user_struct {
 838        atomic_t __count;       /* reference count */
 839        atomic_t processes;     /* How many processes does this user have? */
 840        atomic_t sigpending;    /* How many pending signals does this user have? */
 841#ifdef CONFIG_INOTIFY_USER
 842        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 843        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 844#endif
 845#ifdef CONFIG_FANOTIFY
 846        atomic_t fanotify_listeners;
 847#endif
 848#ifdef CONFIG_EPOLL
 849        atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
 850#endif
 851#ifdef CONFIG_POSIX_MQUEUE
 852        /* protected by mq_lock */
 853        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 854#endif
 855        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 856        unsigned long unix_inflight;    /* How many files in flight in unix sockets */
 857        atomic_long_t pipe_bufs;  /* how many pages are allocated in pipe buffers */
 858
 859#ifdef CONFIG_KEYS
 860        struct key *uid_keyring;        /* UID specific keyring */
 861        struct key *session_keyring;    /* UID's default session keyring */
 862#endif
 863
 864        /* Hash table maintenance information */
 865        struct hlist_node uidhash_node;
 866        kuid_t uid;
 867
 868#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL)
 869        atomic_long_t locked_vm;
 870#endif
 871};
 872
 873extern int uids_sysfs_init(void);
 874
 875extern struct user_struct *find_user(kuid_t);
 876
 877extern struct user_struct root_user;
 878#define INIT_USER (&root_user)
 879
 880
 881struct backing_dev_info;
 882struct reclaim_state;
 883
 884#ifdef CONFIG_SCHED_INFO
 885struct sched_info {
 886        /* cumulative counters */
 887        unsigned long pcount;         /* # of times run on this cpu */
 888        unsigned long long run_delay; /* time spent waiting on a runqueue */
 889
 890        /* timestamps */
 891        unsigned long long last_arrival,/* when we last ran on a cpu */
 892                           last_queued; /* when we were last queued to run */
 893};
 894#endif /* CONFIG_SCHED_INFO */
 895
 896#ifdef CONFIG_TASK_DELAY_ACCT
 897struct task_delay_info {
 898        spinlock_t      lock;
 899        unsigned int    flags;  /* Private per-task flags */
 900
 901        /* For each stat XXX, add following, aligned appropriately
 902         *
 903         * struct timespec XXX_start, XXX_end;
 904         * u64 XXX_delay;
 905         * u32 XXX_count;
 906         *
 907         * Atomicity of updates to XXX_delay, XXX_count protected by
 908         * single lock above (split into XXX_lock if contention is an issue).
 909         */
 910
 911        /*
 912         * XXX_count is incremented on every XXX operation, the delay
 913         * associated with the operation is added to XXX_delay.
 914         * XXX_delay contains the accumulated delay time in nanoseconds.
 915         */
 916        u64 blkio_start;        /* Shared by blkio, swapin */
 917        u64 blkio_delay;        /* wait for sync block io completion */
 918        u64 swapin_delay;       /* wait for swapin block io completion */
 919        u32 blkio_count;        /* total count of the number of sync block */
 920                                /* io operations performed */
 921        u32 swapin_count;       /* total count of the number of swapin block */
 922                                /* io operations performed */
 923
 924        u64 freepages_start;
 925        u64 freepages_delay;    /* wait for memory reclaim */
 926        u32 freepages_count;    /* total count of memory reclaim */
 927};
 928#endif  /* CONFIG_TASK_DELAY_ACCT */
 929
 930static inline int sched_info_on(void)
 931{
 932#ifdef CONFIG_SCHEDSTATS
 933        return 1;
 934#elif defined(CONFIG_TASK_DELAY_ACCT)
 935        extern int delayacct_on;
 936        return delayacct_on;
 937#else
 938        return 0;
 939#endif
 940}
 941
 942#ifdef CONFIG_SCHEDSTATS
 943void force_schedstat_enabled(void);
 944#endif
 945
 946enum cpu_idle_type {
 947        CPU_IDLE,
 948        CPU_NOT_IDLE,
 949        CPU_NEWLY_IDLE,
 950        CPU_MAX_IDLE_TYPES
 951};
 952
 953/*
 954 * Integer metrics need fixed point arithmetic, e.g., sched/fair
 955 * has a few: load, load_avg, util_avg, freq, and capacity.
 956 *
 957 * We define a basic fixed point arithmetic range, and then formalize
 958 * all these metrics based on that basic range.
 959 */
 960# define SCHED_FIXEDPOINT_SHIFT 10
 961# define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
 962
 963/*
 964 * Increase resolution of cpu_capacity calculations
 965 */
 966#define SCHED_CAPACITY_SHIFT    SCHED_FIXEDPOINT_SHIFT
 967#define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
 968
 969/*
 970 * Wake-queues are lists of tasks with a pending wakeup, whose
 971 * callers have already marked the task as woken internally,
 972 * and can thus carry on. A common use case is being able to
 973 * do the wakeups once the corresponding user lock as been
 974 * released.
 975 *
 976 * We hold reference to each task in the list across the wakeup,
 977 * thus guaranteeing that the memory is still valid by the time
 978 * the actual wakeups are performed in wake_up_q().
 979 *
 980 * One per task suffices, because there's never a need for a task to be
 981 * in two wake queues simultaneously; it is forbidden to abandon a task
 982 * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
 983 * already in a wake queue, the wakeup will happen soon and the second
 984 * waker can just skip it.
 985 *
 986 * The WAKE_Q macro declares and initializes the list head.
 987 * wake_up_q() does NOT reinitialize the list; it's expected to be
 988 * called near the end of a function, where the fact that the queue is
 989 * not used again will be easy to see by inspection.
 990 *
 991 * Note that this can cause spurious wakeups. schedule() callers
 992 * must ensure the call is done inside a loop, confirming that the
 993 * wakeup condition has in fact occurred.
 994 */
 995struct wake_q_node {
 996        struct wake_q_node *next;
 997};
 998
 999struct wake_q_head {
1000        struct wake_q_node *first;
1001        struct wake_q_node **lastp;
1002};
1003
1004#define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
1005
1006#define WAKE_Q(name)                                    \
1007        struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
1008
1009extern void wake_q_add(struct wake_q_head *head,
1010                       struct task_struct *task);
1011extern void wake_up_q(struct wake_q_head *head);
1012
1013/*
1014 * sched-domains (multiprocessor balancing) declarations:
1015 */
1016#ifdef CONFIG_SMP
1017#define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
1018#define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
1019#define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
1020#define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
1021#define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
1022#define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
1023#define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu power */
1024#define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
1025#define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
1026#define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
1027#define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
1028#define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
1029#define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
1030#define SD_NUMA                 0x4000  /* cross-node balancing */
1031
1032#ifdef CONFIG_SCHED_SMT
1033static inline int cpu_smt_flags(void)
1034{
1035        return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
1036}
1037#endif
1038
1039#ifdef CONFIG_SCHED_MC
1040static inline int cpu_core_flags(void)
1041{
1042        return SD_SHARE_PKG_RESOURCES;
1043}
1044#endif
1045
1046#ifdef CONFIG_NUMA
1047static inline int cpu_numa_flags(void)
1048{
1049        return SD_NUMA;
1050}
1051#endif
1052
1053struct sched_domain_attr {
1054        int relax_domain_level;
1055};
1056
1057#define SD_ATTR_INIT    (struct sched_domain_attr) {    \
1058        .relax_domain_level = -1,                       \
1059}
1060
1061extern int sched_domain_level_max;
1062
1063struct sched_group;
1064
1065struct sched_domain {
1066        /* These fields must be setup */
1067        struct sched_domain *parent;    /* top domain must be null terminated */
1068        struct sched_domain *child;     /* bottom domain must be null terminated */
1069        struct sched_group *groups;     /* the balancing groups of the domain */
1070        unsigned long min_interval;     /* Minimum balance interval ms */
1071        unsigned long max_interval;     /* Maximum balance interval ms */
1072        unsigned int busy_factor;       /* less balancing by factor if busy */
1073        unsigned int imbalance_pct;     /* No balance until over watermark */
1074        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
1075        unsigned int busy_idx;
1076        unsigned int idle_idx;
1077        unsigned int newidle_idx;
1078        unsigned int wake_idx;
1079        unsigned int forkexec_idx;
1080        unsigned int smt_gain;
1081
1082        int nohz_idle;                  /* NOHZ IDLE status */
1083        int flags;                      /* See SD_* */
1084        int level;
1085
1086        /* Runtime fields. */
1087        unsigned long last_balance;     /* init to jiffies. units in jiffies */
1088        unsigned int balance_interval;  /* initialise to 1. units in ms. */
1089        unsigned int nr_balance_failed; /* initialise to 0 */
1090
1091        /* idle_balance() stats */
1092        u64 max_newidle_lb_cost;
1093        unsigned long next_decay_max_lb_cost;
1094
1095#ifdef CONFIG_SCHEDSTATS
1096        /* load_balance() stats */
1097        unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1098        unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1099        unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1100        unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1101        unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1102        unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1103        unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1104        unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1105
1106        /* Active load balancing */
1107        unsigned int alb_count;
1108        unsigned int alb_failed;
1109        unsigned int alb_pushed;
1110
1111        /* SD_BALANCE_EXEC stats */
1112        unsigned int sbe_count;
1113        unsigned int sbe_balanced;
1114        unsigned int sbe_pushed;
1115
1116        /* SD_BALANCE_FORK stats */
1117        unsigned int sbf_count;
1118        unsigned int sbf_balanced;
1119        unsigned int sbf_pushed;
1120
1121        /* try_to_wake_up() stats */
1122        unsigned int ttwu_wake_remote;
1123        unsigned int ttwu_move_affine;
1124        unsigned int ttwu_move_balance;
1125#endif
1126#ifdef CONFIG_SCHED_DEBUG
1127        char *name;
1128#endif
1129        union {
1130                void *private;          /* used during construction */
1131                struct rcu_head rcu;    /* used during destruction */
1132        };
1133
1134        unsigned int span_weight;
1135        /*
1136         * Span of all CPUs in this domain.
1137         *
1138         * NOTE: this field is variable length. (Allocated dynamically
1139         * by attaching extra space to the end of the structure,
1140         * depending on how many CPUs the kernel has booted up with)
1141         */
1142        unsigned long span[0];
1143};
1144
1145static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1146{
1147        return to_cpumask(sd->span);
1148}
1149
1150extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1151                                    struct sched_domain_attr *dattr_new);
1152
1153/* Allocate an array of sched domains, for partition_sched_domains(). */
1154cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1155void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1156
1157bool cpus_share_cache(int this_cpu, int that_cpu);
1158
1159typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1160typedef int (*sched_domain_flags_f)(void);
1161
1162#define SDTL_OVERLAP    0x01
1163
1164struct sd_data {
1165        struct sched_domain **__percpu sd;
1166        struct sched_group **__percpu sg;
1167        struct sched_group_capacity **__percpu sgc;
1168};
1169
1170struct sched_domain_topology_level {
1171        sched_domain_mask_f mask;
1172        sched_domain_flags_f sd_flags;
1173        int                 flags;
1174        int                 numa_level;
1175        struct sd_data      data;
1176#ifdef CONFIG_SCHED_DEBUG
1177        char                *name;
1178#endif
1179};
1180
1181extern void set_sched_topology(struct sched_domain_topology_level *tl);
1182extern void wake_up_if_idle(int cpu);
1183
1184#ifdef CONFIG_SCHED_DEBUG
1185# define SD_INIT_NAME(type)             .name = #type
1186#else
1187# define SD_INIT_NAME(type)
1188#endif
1189
1190#else /* CONFIG_SMP */
1191
1192struct sched_domain_attr;
1193
1194static inline void
1195partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1196                        struct sched_domain_attr *dattr_new)
1197{
1198}
1199
1200static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1201{
1202        return true;
1203}
1204
1205#endif  /* !CONFIG_SMP */
1206
1207
1208struct io_context;                      /* See blkdev.h */
1209
1210
1211#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1212extern void prefetch_stack(struct task_struct *t);
1213#else
1214static inline void prefetch_stack(struct task_struct *t) { }
1215#endif
1216
1217struct audit_context;           /* See audit.c */
1218struct mempolicy;
1219struct pipe_inode_info;
1220struct uts_namespace;
1221
1222struct load_weight {
1223        unsigned long weight;
1224        u32 inv_weight;
1225};
1226
1227/*
1228 * The load_avg/util_avg accumulates an infinite geometric series
1229 * (see __update_load_avg() in kernel/sched/fair.c).
1230 *
1231 * [load_avg definition]
1232 *
1233 *   load_avg = runnable% * scale_load_down(load)
1234 *
1235 * where runnable% is the time ratio that a sched_entity is runnable.
1236 * For cfs_rq, it is the aggregated load_avg of all runnable and
1237 * blocked sched_entities.
1238 *
1239 * load_avg may also take frequency scaling into account:
1240 *
1241 *   load_avg = runnable% * scale_load_down(load) * freq%
1242 *
1243 * where freq% is the CPU frequency normalized to the highest frequency.
1244 *
1245 * [util_avg definition]
1246 *
1247 *   util_avg = running% * SCHED_CAPACITY_SCALE
1248 *
1249 * where running% is the time ratio that a sched_entity is running on
1250 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
1251 * and blocked sched_entities.
1252 *
1253 * util_avg may also factor frequency scaling and CPU capacity scaling:
1254 *
1255 *   util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
1256 *
1257 * where freq% is the same as above, and capacity% is the CPU capacity
1258 * normalized to the greatest capacity (due to uarch differences, etc).
1259 *
1260 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
1261 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
1262 * we therefore scale them to as large a range as necessary. This is for
1263 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
1264 *
1265 * [Overflow issue]
1266 *
1267 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
1268 * with the highest load (=88761), always runnable on a single cfs_rq,
1269 * and should not overflow as the number already hits PID_MAX_LIMIT.
1270 *
1271 * For all other cases (including 32-bit kernels), struct load_weight's
1272 * weight will overflow first before we do, because:
1273 *
1274 *    Max(load_avg) <= Max(load.weight)
1275 *
1276 * Then it is the load_weight's responsibility to consider overflow
1277 * issues.
1278 */
1279struct sched_avg {
1280        u64 last_update_time, load_sum;
1281        u32 util_sum, period_contrib;
1282        unsigned long load_avg, util_avg;
1283};
1284
1285#ifdef CONFIG_SCHEDSTATS
1286struct sched_statistics {
1287        u64                     wait_start;
1288        u64                     wait_max;
1289        u64                     wait_count;
1290        u64                     wait_sum;
1291        u64                     iowait_count;
1292        u64                     iowait_sum;
1293
1294        u64                     sleep_start;
1295        u64                     sleep_max;
1296        s64                     sum_sleep_runtime;
1297
1298        u64                     block_start;
1299        u64                     block_max;
1300        u64                     exec_max;
1301        u64                     slice_max;
1302
1303        u64                     nr_migrations_cold;
1304        u64                     nr_failed_migrations_affine;
1305        u64                     nr_failed_migrations_running;
1306        u64                     nr_failed_migrations_hot;
1307        u64                     nr_forced_migrations;
1308
1309        u64                     nr_wakeups;
1310        u64                     nr_wakeups_sync;
1311        u64                     nr_wakeups_migrate;
1312        u64                     nr_wakeups_local;
1313        u64                     nr_wakeups_remote;
1314        u64                     nr_wakeups_affine;
1315        u64                     nr_wakeups_affine_attempts;
1316        u64                     nr_wakeups_passive;
1317        u64                     nr_wakeups_idle;
1318};
1319#endif
1320
1321struct sched_entity {
1322        struct load_weight      load;           /* for load-balancing */
1323        struct rb_node          run_node;
1324        struct list_head        group_node;
1325        unsigned int            on_rq;
1326
1327        u64                     exec_start;
1328        u64                     sum_exec_runtime;
1329        u64                     vruntime;
1330        u64                     prev_sum_exec_runtime;
1331
1332        u64                     nr_migrations;
1333
1334#ifdef CONFIG_SCHEDSTATS
1335        struct sched_statistics statistics;
1336#endif
1337
1338#ifdef CONFIG_FAIR_GROUP_SCHED
1339        int                     depth;
1340        struct sched_entity     *parent;
1341        /* rq on which this entity is (to be) queued: */
1342        struct cfs_rq           *cfs_rq;
1343        /* rq "owned" by this entity/group: */
1344        struct cfs_rq           *my_q;
1345#endif
1346
1347#ifdef CONFIG_SMP
1348        /*
1349         * Per entity load average tracking.
1350         *
1351         * Put into separate cache line so it does not
1352         * collide with read-mostly values above.
1353         */
1354        struct sched_avg        avg ____cacheline_aligned_in_smp;
1355#endif
1356};
1357
1358struct sched_rt_entity {
1359        struct list_head run_list;
1360        unsigned long timeout;
1361        unsigned long watchdog_stamp;
1362        unsigned int time_slice;
1363        unsigned short on_rq;
1364        unsigned short on_list;
1365
1366        struct sched_rt_entity *back;
1367#ifdef CONFIG_RT_GROUP_SCHED
1368        struct sched_rt_entity  *parent;
1369        /* rq on which this entity is (to be) queued: */
1370        struct rt_rq            *rt_rq;
1371        /* rq "owned" by this entity/group: */
1372        struct rt_rq            *my_q;
1373#endif
1374};
1375
1376struct sched_dl_entity {
1377        struct rb_node  rb_node;
1378
1379        /*
1380         * Original scheduling parameters. Copied here from sched_attr
1381         * during sched_setattr(), they will remain the same until
1382         * the next sched_setattr().
1383         */
1384        u64 dl_runtime;         /* maximum runtime for each instance    */
1385        u64 dl_deadline;        /* relative deadline of each instance   */
1386        u64 dl_period;          /* separation of two instances (period) */
1387        u64 dl_bw;              /* dl_runtime / dl_deadline             */
1388
1389        /*
1390         * Actual scheduling parameters. Initialized with the values above,
1391         * they are continously updated during task execution. Note that
1392         * the remaining runtime could be < 0 in case we are in overrun.
1393         */
1394        s64 runtime;            /* remaining runtime for this instance  */
1395        u64 deadline;           /* absolute deadline for this instance  */
1396        unsigned int flags;     /* specifying the scheduler behaviour   */
1397
1398        /*
1399         * Some bool flags:
1400         *
1401         * @dl_throttled tells if we exhausted the runtime. If so, the
1402         * task has to wait for a replenishment to be performed at the
1403         * next firing of dl_timer.
1404         *
1405         * @dl_boosted tells if we are boosted due to DI. If so we are
1406         * outside bandwidth enforcement mechanism (but only until we
1407         * exit the critical section);
1408         *
1409         * @dl_yielded tells if task gave up the cpu before consuming
1410         * all its available runtime during the last job.
1411         */
1412        int dl_throttled, dl_boosted, dl_yielded;
1413
1414        /*
1415         * Bandwidth enforcement timer. Each -deadline task has its
1416         * own bandwidth to be enforced, thus we need one timer per task.
1417         */
1418        struct hrtimer dl_timer;
1419};
1420
1421union rcu_special {
1422        struct {
1423                u8 blocked;
1424                u8 need_qs;
1425                u8 exp_need_qs;
1426                u8 pad; /* Otherwise the compiler can store garbage here. */
1427        } b; /* Bits. */
1428        u32 s; /* Set of bits. */
1429};
1430struct rcu_node;
1431
1432enum perf_event_task_context {
1433        perf_invalid_context = -1,
1434        perf_hw_context = 0,
1435        perf_sw_context,
1436        perf_nr_task_contexts,
1437};
1438
1439/* Track pages that require TLB flushes */
1440struct tlbflush_unmap_batch {
1441        /*
1442         * Each bit set is a CPU that potentially has a TLB entry for one of
1443         * the PFNs being flushed. See set_tlb_ubc_flush_pending().
1444         */
1445        struct cpumask cpumask;
1446
1447        /* True if any bit in cpumask is set */
1448        bool flush_required;
1449
1450        /*
1451         * If true then the PTE was dirty when unmapped. The entry must be
1452         * flushed before IO is initiated or a stale TLB entry potentially
1453         * allows an update without redirtying the page.
1454         */
1455        bool writable;
1456};
1457
1458struct task_struct {
1459        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1460        void *stack;
1461        atomic_t usage;
1462        unsigned int flags;     /* per process flags, defined below */
1463        unsigned int ptrace;
1464
1465#ifdef CONFIG_SMP
1466        struct llist_node wake_entry;
1467        int on_cpu;
1468        unsigned int wakee_flips;
1469        unsigned long wakee_flip_decay_ts;
1470        struct task_struct *last_wakee;
1471
1472        int wake_cpu;
1473#endif
1474        int on_rq;
1475
1476        int prio, static_prio, normal_prio;
1477        unsigned int rt_priority;
1478        const struct sched_class *sched_class;
1479        struct sched_entity se;
1480        struct sched_rt_entity rt;
1481#ifdef CONFIG_CGROUP_SCHED
1482        struct task_group *sched_task_group;
1483#endif
1484        struct sched_dl_entity dl;
1485
1486#ifdef CONFIG_PREEMPT_NOTIFIERS
1487        /* list of struct preempt_notifier: */
1488        struct hlist_head preempt_notifiers;
1489#endif
1490
1491#ifdef CONFIG_BLK_DEV_IO_TRACE
1492        unsigned int btrace_seq;
1493#endif
1494
1495        unsigned int policy;
1496        int nr_cpus_allowed;
1497        cpumask_t cpus_allowed;
1498
1499#ifdef CONFIG_PREEMPT_RCU
1500        int rcu_read_lock_nesting;
1501        union rcu_special rcu_read_unlock_special;
1502        struct list_head rcu_node_entry;
1503        struct rcu_node *rcu_blocked_node;
1504#endif /* #ifdef CONFIG_PREEMPT_RCU */
1505#ifdef CONFIG_TASKS_RCU
1506        unsigned long rcu_tasks_nvcsw;
1507        bool rcu_tasks_holdout;
1508        struct list_head rcu_tasks_holdout_list;
1509        int rcu_tasks_idle_cpu;
1510#endif /* #ifdef CONFIG_TASKS_RCU */
1511
1512#ifdef CONFIG_SCHED_INFO
1513        struct sched_info sched_info;
1514#endif
1515
1516        struct list_head tasks;
1517#ifdef CONFIG_SMP
1518        struct plist_node pushable_tasks;
1519        struct rb_node pushable_dl_tasks;
1520#endif
1521
1522        struct mm_struct *mm, *active_mm;
1523        /* per-thread vma caching */
1524        u32 vmacache_seqnum;
1525        struct vm_area_struct *vmacache[VMACACHE_SIZE];
1526#if defined(SPLIT_RSS_COUNTING)
1527        struct task_rss_stat    rss_stat;
1528#endif
1529/* task state */
1530        int exit_state;
1531        int exit_code, exit_signal;
1532        int pdeath_signal;  /*  The signal sent when the parent dies  */
1533        unsigned long jobctl;   /* JOBCTL_*, siglock protected */
1534
1535        /* Used for emulating ABI behavior of previous Linux versions */
1536        unsigned int personality;
1537
1538        /* scheduler bits, serialized by scheduler locks */
1539        unsigned sched_reset_on_fork:1;
1540        unsigned sched_contributes_to_load:1;
1541        unsigned sched_migrated:1;
1542        unsigned sched_remote_wakeup:1;
1543        unsigned :0; /* force alignment to the next boundary */
1544
1545        /* unserialized, strictly 'current' */
1546        unsigned in_execve:1; /* bit to tell LSMs we're in execve */
1547        unsigned in_iowait:1;
1548#ifdef CONFIG_MEMCG
1549        unsigned memcg_may_oom:1;
1550#ifndef CONFIG_SLOB
1551        unsigned memcg_kmem_skip_account:1;
1552#endif
1553#endif
1554#ifdef CONFIG_COMPAT_BRK
1555        unsigned brk_randomized:1;
1556#endif
1557
1558        unsigned long atomic_flags; /* Flags needing atomic access. */
1559
1560        struct restart_block restart_block;
1561
1562        pid_t pid;
1563        pid_t tgid;
1564
1565#ifdef CONFIG_CC_STACKPROTECTOR
1566        /* Canary value for the -fstack-protector gcc feature */
1567        unsigned long stack_canary;
1568#endif
1569        /*
1570         * pointers to (original) parent process, youngest child, younger sibling,
1571         * older sibling, respectively.  (p->father can be replaced with
1572         * p->real_parent->pid)
1573         */
1574        struct task_struct __rcu *real_parent; /* real parent process */
1575        struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1576        /*
1577         * children/sibling forms the list of my natural children
1578         */
1579        struct list_head children;      /* list of my children */
1580        struct list_head sibling;       /* linkage in my parent's children list */
1581        struct task_struct *group_leader;       /* threadgroup leader */
1582
1583        /*
1584         * ptraced is the list of tasks this task is using ptrace on.
1585         * This includes both natural children and PTRACE_ATTACH targets.
1586         * p->ptrace_entry is p's link on the p->parent->ptraced list.
1587         */
1588        struct list_head ptraced;
1589        struct list_head ptrace_entry;
1590
1591        /* PID/PID hash table linkage. */
1592        struct pid_link pids[PIDTYPE_MAX];
1593        struct list_head thread_group;
1594        struct list_head thread_node;
1595
1596        struct completion *vfork_done;          /* for vfork() */
1597        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1598        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1599
1600        cputime_t utime, stime, utimescaled, stimescaled;
1601        cputime_t gtime;
1602        struct prev_cputime prev_cputime;
1603#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1604        seqcount_t vtime_seqcount;
1605        unsigned long long vtime_snap;
1606        enum {
1607                /* Task is sleeping or running in a CPU with VTIME inactive */
1608                VTIME_INACTIVE = 0,
1609                /* Task runs in userspace in a CPU with VTIME active */
1610                VTIME_USER,
1611                /* Task runs in kernelspace in a CPU with VTIME active */
1612                VTIME_SYS,
1613        } vtime_snap_whence;
1614#endif
1615
1616#ifdef CONFIG_NO_HZ_FULL
1617        atomic_t tick_dep_mask;
1618#endif
1619        unsigned long nvcsw, nivcsw; /* context switch counts */
1620        u64 start_time;         /* monotonic time in nsec */
1621        u64 real_start_time;    /* boot based time in nsec */
1622/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1623        unsigned long min_flt, maj_flt;
1624
1625        struct task_cputime cputime_expires;
1626        struct list_head cpu_timers[3];
1627
1628/* process credentials */
1629        const struct cred __rcu *real_cred; /* objective and real subjective task
1630                                         * credentials (COW) */
1631        const struct cred __rcu *cred;  /* effective (overridable) subjective task
1632                                         * credentials (COW) */
1633        char comm[TASK_COMM_LEN]; /* executable name excluding path
1634                                     - access with [gs]et_task_comm (which lock
1635                                       it with task_lock())
1636                                     - initialized normally by setup_new_exec */
1637/* file system info */
1638        struct nameidata *nameidata;
1639#ifdef CONFIG_SYSVIPC
1640/* ipc stuff */
1641        struct sysv_sem sysvsem;
1642        struct sysv_shm sysvshm;
1643#endif
1644#ifdef CONFIG_DETECT_HUNG_TASK
1645/* hung task detection */
1646        unsigned long last_switch_count;
1647#endif
1648/* filesystem information */
1649        struct fs_struct *fs;
1650/* open file information */
1651        struct files_struct *files;
1652/* namespaces */
1653        struct nsproxy *nsproxy;
1654/* signal handlers */
1655        struct signal_struct *signal;
1656        struct sighand_struct *sighand;
1657
1658        sigset_t blocked, real_blocked;
1659        sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1660        struct sigpending pending;
1661
1662        unsigned long sas_ss_sp;
1663        size_t sas_ss_size;
1664        unsigned sas_ss_flags;
1665
1666        struct callback_head *task_works;
1667
1668        struct audit_context *audit_context;
1669#ifdef CONFIG_AUDITSYSCALL
1670        kuid_t loginuid;
1671        unsigned int sessionid;
1672#endif
1673        struct seccomp seccomp;
1674
1675/* Thread group tracking */
1676        u32 parent_exec_id;
1677        u32 self_exec_id;
1678/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1679 * mempolicy */
1680        spinlock_t alloc_lock;
1681
1682        /* Protection of the PI data structures: */
1683        raw_spinlock_t pi_lock;
1684
1685        struct wake_q_node wake_q;
1686
1687#ifdef CONFIG_RT_MUTEXES
1688        /* PI waiters blocked on a rt_mutex held by this task */
1689        struct rb_root pi_waiters;
1690        struct rb_node *pi_waiters_leftmost;
1691        /* Deadlock detection and priority inheritance handling */
1692        struct rt_mutex_waiter *pi_blocked_on;
1693#endif
1694
1695#ifdef CONFIG_DEBUG_MUTEXES
1696        /* mutex deadlock detection */
1697        struct mutex_waiter *blocked_on;
1698#endif
1699#ifdef CONFIG_TRACE_IRQFLAGS
1700        unsigned int irq_events;
1701        unsigned long hardirq_enable_ip;
1702        unsigned long hardirq_disable_ip;
1703        unsigned int hardirq_enable_event;
1704        unsigned int hardirq_disable_event;
1705        int hardirqs_enabled;
1706        int hardirq_context;
1707        unsigned long softirq_disable_ip;
1708        unsigned long softirq_enable_ip;
1709        unsigned int softirq_disable_event;
1710        unsigned int softirq_enable_event;
1711        int softirqs_enabled;
1712        int softirq_context;
1713#endif
1714#ifdef CONFIG_LOCKDEP
1715# define MAX_LOCK_DEPTH 48UL
1716        u64 curr_chain_key;
1717        int lockdep_depth;
1718        unsigned int lockdep_recursion;
1719        struct held_lock held_locks[MAX_LOCK_DEPTH];
1720        gfp_t lockdep_reclaim_gfp;
1721#endif
1722#ifdef CONFIG_UBSAN
1723        unsigned int in_ubsan;
1724#endif
1725
1726/* journalling filesystem info */
1727        void *journal_info;
1728
1729/* stacked block device info */
1730        struct bio_list *bio_list;
1731
1732#ifdef CONFIG_BLOCK
1733/* stack plugging */
1734        struct blk_plug *plug;
1735#endif
1736
1737/* VM state */
1738        struct reclaim_state *reclaim_state;
1739
1740        struct backing_dev_info *backing_dev_info;
1741
1742        struct io_context *io_context;
1743
1744        unsigned long ptrace_message;
1745        siginfo_t *last_siginfo; /* For ptrace use.  */
1746        struct task_io_accounting ioac;
1747#if defined(CONFIG_TASK_XACCT)
1748        u64 acct_rss_mem1;      /* accumulated rss usage */
1749        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1750        cputime_t acct_timexpd; /* stime + utime since last update */
1751#endif
1752#ifdef CONFIG_CPUSETS
1753        nodemask_t mems_allowed;        /* Protected by alloc_lock */
1754        seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1755        int cpuset_mem_spread_rotor;
1756        int cpuset_slab_spread_rotor;
1757#endif
1758#ifdef CONFIG_CGROUPS
1759        /* Control Group info protected by css_set_lock */
1760        struct css_set __rcu *cgroups;
1761        /* cg_list protected by css_set_lock and tsk->alloc_lock */
1762        struct list_head cg_list;
1763#endif
1764#ifdef CONFIG_FUTEX
1765        struct robust_list_head __user *robust_list;
1766#ifdef CONFIG_COMPAT
1767        struct compat_robust_list_head __user *compat_robust_list;
1768#endif
1769        struct list_head pi_state_list;
1770        struct futex_pi_state *pi_state_cache;
1771#endif
1772#ifdef CONFIG_PERF_EVENTS
1773        struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1774        struct mutex perf_event_mutex;
1775        struct list_head perf_event_list;
1776#endif
1777#ifdef CONFIG_DEBUG_PREEMPT
1778        unsigned long preempt_disable_ip;
1779#endif
1780#ifdef CONFIG_NUMA
1781        struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1782        short il_next;
1783        short pref_node_fork;
1784#endif
1785#ifdef CONFIG_NUMA_BALANCING
1786        int numa_scan_seq;
1787        unsigned int numa_scan_period;
1788        unsigned int numa_scan_period_max;
1789        int numa_preferred_nid;
1790        unsigned long numa_migrate_retry;
1791        u64 node_stamp;                 /* migration stamp  */
1792        u64 last_task_numa_placement;
1793        u64 last_sum_exec_runtime;
1794        struct callback_head numa_work;
1795
1796        struct list_head numa_entry;
1797        struct numa_group *numa_group;
1798
1799        /*
1800         * numa_faults is an array split into four regions:
1801         * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1802         * in this precise order.
1803         *
1804         * faults_memory: Exponential decaying average of faults on a per-node
1805         * basis. Scheduling placement decisions are made based on these
1806         * counts. The values remain static for the duration of a PTE scan.
1807         * faults_cpu: Track the nodes the process was running on when a NUMA
1808         * hinting fault was incurred.
1809         * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1810         * during the current scan window. When the scan completes, the counts
1811         * in faults_memory and faults_cpu decay and these values are copied.
1812         */
1813        unsigned long *numa_faults;
1814        unsigned long total_numa_faults;
1815
1816        /*
1817         * numa_faults_locality tracks if faults recorded during the last
1818         * scan window were remote/local or failed to migrate. The task scan
1819         * period is adapted based on the locality of the faults with different
1820         * weights depending on whether they were shared or private faults
1821         */
1822        unsigned long numa_faults_locality[3];
1823
1824        unsigned long numa_pages_migrated;
1825#endif /* CONFIG_NUMA_BALANCING */
1826
1827#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1828        struct tlbflush_unmap_batch tlb_ubc;
1829#endif
1830
1831        struct rcu_head rcu;
1832
1833        /*
1834         * cache last used pipe for splice
1835         */
1836        struct pipe_inode_info *splice_pipe;
1837
1838        struct page_frag task_frag;
1839
1840#ifdef  CONFIG_TASK_DELAY_ACCT
1841        struct task_delay_info *delays;
1842#endif
1843#ifdef CONFIG_FAULT_INJECTION
1844        int make_it_fail;
1845#endif
1846        /*
1847         * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1848         * balance_dirty_pages() for some dirty throttling pause
1849         */
1850        int nr_dirtied;
1851        int nr_dirtied_pause;
1852        unsigned long dirty_paused_when; /* start of a write-and-pause period */
1853
1854#ifdef CONFIG_LATENCYTOP
1855        int latency_record_count;
1856        struct latency_record latency_record[LT_SAVECOUNT];
1857#endif
1858        /*
1859         * time slack values; these are used to round up poll() and
1860         * select() etc timeout values. These are in nanoseconds.
1861         */
1862        u64 timer_slack_ns;
1863        u64 default_timer_slack_ns;
1864
1865#ifdef CONFIG_KASAN
1866        unsigned int kasan_depth;
1867#endif
1868#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1869        /* Index of current stored address in ret_stack */
1870        int curr_ret_stack;
1871        /* Stack of return addresses for return function tracing */
1872        struct ftrace_ret_stack *ret_stack;
1873        /* time stamp for last schedule */
1874        unsigned long long ftrace_timestamp;
1875        /*
1876         * Number of functions that haven't been traced
1877         * because of depth overrun.
1878         */
1879        atomic_t trace_overrun;
1880        /* Pause for the tracing */
1881        atomic_t tracing_graph_pause;
1882#endif
1883#ifdef CONFIG_TRACING
1884        /* state flags for use by tracers */
1885        unsigned long trace;
1886        /* bitmask and counter of trace recursion */
1887        unsigned long trace_recursion;
1888#endif /* CONFIG_TRACING */
1889#ifdef CONFIG_KCOV
1890        /* Coverage collection mode enabled for this task (0 if disabled). */
1891        enum kcov_mode kcov_mode;
1892        /* Size of the kcov_area. */
1893        unsigned        kcov_size;
1894        /* Buffer for coverage collection. */
1895        void            *kcov_area;
1896        /* kcov desciptor wired with this task or NULL. */
1897        struct kcov     *kcov;
1898#endif
1899#ifdef CONFIG_MEMCG
1900        struct mem_cgroup *memcg_in_oom;
1901        gfp_t memcg_oom_gfp_mask;
1902        int memcg_oom_order;
1903
1904        /* number of pages to reclaim on returning to userland */
1905        unsigned int memcg_nr_pages_over_high;
1906#endif
1907#ifdef CONFIG_UPROBES
1908        struct uprobe_task *utask;
1909#endif
1910#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1911        unsigned int    sequential_io;
1912        unsigned int    sequential_io_avg;
1913#endif
1914#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1915        unsigned long   task_state_change;
1916#endif
1917        int pagefault_disabled;
1918#ifdef CONFIG_MMU
1919        struct task_struct *oom_reaper_list;
1920#endif
1921/* CPU-specific state of this task */
1922        struct thread_struct thread;
1923/*
1924 * WARNING: on x86, 'thread_struct' contains a variable-sized
1925 * structure.  It *MUST* be at the end of 'task_struct'.
1926 *
1927 * Do not put anything below here!
1928 */
1929};
1930
1931#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
1932extern int arch_task_struct_size __read_mostly;
1933#else
1934# define arch_task_struct_size (sizeof(struct task_struct))
1935#endif
1936
1937/* Future-safe accessor for struct task_struct's cpus_allowed. */
1938#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1939
1940static inline int tsk_nr_cpus_allowed(struct task_struct *p)
1941{
1942        return p->nr_cpus_allowed;
1943}
1944
1945#define TNF_MIGRATED    0x01
1946#define TNF_NO_GROUP    0x02
1947#define TNF_SHARED      0x04
1948#define TNF_FAULT_LOCAL 0x08
1949#define TNF_MIGRATE_FAIL 0x10
1950
1951#ifdef CONFIG_NUMA_BALANCING
1952extern void task_numa_fault(int last_node, int node, int pages, int flags);
1953extern pid_t task_numa_group_id(struct task_struct *p);
1954extern void set_numabalancing_state(bool enabled);
1955extern void task_numa_free(struct task_struct *p);
1956extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1957                                        int src_nid, int dst_cpu);
1958#else
1959static inline void task_numa_fault(int last_node, int node, int pages,
1960                                   int flags)
1961{
1962}
1963static inline pid_t task_numa_group_id(struct task_struct *p)
1964{
1965        return 0;
1966}
1967static inline void set_numabalancing_state(bool enabled)
1968{
1969}
1970static inline void task_numa_free(struct task_struct *p)
1971{
1972}
1973static inline bool should_numa_migrate_memory(struct task_struct *p,
1974                                struct page *page, int src_nid, int dst_cpu)
1975{
1976        return true;
1977}
1978#endif
1979
1980static inline struct pid *task_pid(struct task_struct *task)
1981{
1982        return task->pids[PIDTYPE_PID].pid;
1983}
1984
1985static inline struct pid *task_tgid(struct task_struct *task)
1986{
1987        return task->group_leader->pids[PIDTYPE_PID].pid;
1988}
1989
1990/*
1991 * Without tasklist or rcu lock it is not safe to dereference
1992 * the result of task_pgrp/task_session even if task == current,
1993 * we can race with another thread doing sys_setsid/sys_setpgid.
1994 */
1995static inline struct pid *task_pgrp(struct task_struct *task)
1996{
1997        return task->group_leader->pids[PIDTYPE_PGID].pid;
1998}
1999
2000static inline struct pid *task_session(struct task_struct *task)
2001{
2002        return task->group_leader->pids[PIDTYPE_SID].pid;
2003}
2004
2005struct pid_namespace;
2006
2007/*
2008 * the helpers to get the task's different pids as they are seen
2009 * from various namespaces
2010 *
2011 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
2012 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
2013 *                     current.
2014 * task_xid_nr_ns()  : id seen from the ns specified;
2015 *
2016 * set_task_vxid()   : assigns a virtual id to a task;
2017 *
2018 * see also pid_nr() etc in include/linux/pid.h
2019 */
2020pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
2021                        struct pid_namespace *ns);
2022
2023static inline pid_t task_pid_nr(struct task_struct *tsk)
2024{
2025        return tsk->pid;
2026}
2027
2028static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
2029                                        struct pid_namespace *ns)
2030{
2031        return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
2032}
2033
2034static inline pid_t task_pid_vnr(struct task_struct *tsk)
2035{
2036        return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
2037}
2038
2039
2040static inline pid_t task_tgid_nr(struct task_struct *tsk)
2041{
2042        return tsk->tgid;
2043}
2044
2045pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
2046
2047static inline pid_t task_tgid_vnr(struct task_struct *tsk)
2048{
2049        return pid_vnr(task_tgid(tsk));
2050}
2051
2052
2053static inline int pid_alive(const struct task_struct *p);
2054static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
2055{
2056        pid_t pid = 0;
2057
2058        rcu_read_lock();
2059        if (pid_alive(tsk))
2060                pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
2061        rcu_read_unlock();
2062
2063        return pid;
2064}
2065
2066static inline pid_t task_ppid_nr(const struct task_struct *tsk)
2067{
2068        return task_ppid_nr_ns(tsk, &init_pid_ns);
2069}
2070
2071static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
2072                                        struct pid_namespace *ns)
2073{
2074        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
2075}
2076
2077static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
2078{
2079        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
2080}
2081
2082
2083static inline pid_t task_session_nr_ns(struct task_struct *tsk,
2084                                        struct pid_namespace *ns)
2085{
2086        return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
2087}
2088
2089static inline pid_t task_session_vnr(struct task_struct *tsk)
2090{
2091        return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
2092}
2093
2094/* obsolete, do not use */
2095static inline pid_t task_pgrp_nr(struct task_struct *tsk)
2096{
2097        return task_pgrp_nr_ns(tsk, &init_pid_ns);
2098}
2099
2100/**
2101 * pid_alive - check that a task structure is not stale
2102 * @p: Task structure to be checked.
2103 *
2104 * Test if a process is not yet dead (at most zombie state)
2105 * If pid_alive fails, then pointers within the task structure
2106 * can be stale and must not be dereferenced.
2107 *
2108 * Return: 1 if the process is alive. 0 otherwise.
2109 */
2110static inline int pid_alive(const struct task_struct *p)
2111{
2112        return p->pids[PIDTYPE_PID].pid != NULL;
2113}
2114
2115/**
2116 * is_global_init - check if a task structure is init. Since init
2117 * is free to have sub-threads we need to check tgid.
2118 * @tsk: Task structure to be checked.
2119 *
2120 * Check if a task structure is the first user space task the kernel created.
2121 *
2122 * Return: 1 if the task structure is init. 0 otherwise.
2123 */
2124static inline int is_global_init(struct task_struct *tsk)
2125{
2126        return task_tgid_nr(tsk) == 1;
2127}
2128
2129extern struct pid *cad_pid;
2130
2131extern void free_task(struct task_struct *tsk);
2132#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
2133
2134extern void __put_task_struct(struct task_struct *t);
2135
2136static inline void put_task_struct(struct task_struct *t)
2137{
2138        if (atomic_dec_and_test(&t->usage))
2139                __put_task_struct(t);
2140}
2141
2142#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
2143extern void task_cputime(struct task_struct *t,
2144                         cputime_t *utime, cputime_t *stime);
2145extern void task_cputime_scaled(struct task_struct *t,
2146                                cputime_t *utimescaled, cputime_t *stimescaled);
2147extern cputime_t task_gtime(struct task_struct *t);
2148#else
2149static inline void task_cputime(struct task_struct *t,
2150                                cputime_t *utime, cputime_t *stime)
2151{
2152        if (utime)
2153                *utime = t->utime;
2154        if (stime)
2155                *stime = t->stime;
2156}
2157
2158static inline void task_cputime_scaled(struct task_struct *t,
2159                                       cputime_t *utimescaled,
2160                                       cputime_t *stimescaled)
2161{
2162        if (utimescaled)
2163                *utimescaled = t->utimescaled;
2164        if (stimescaled)
2165                *stimescaled = t->stimescaled;
2166}
2167
2168static inline cputime_t task_gtime(struct task_struct *t)
2169{
2170        return t->gtime;
2171}
2172#endif
2173extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2174extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2175
2176/*
2177 * Per process flags
2178 */
2179#define PF_EXITING      0x00000004      /* getting shut down */
2180#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
2181#define PF_VCPU         0x00000010      /* I'm a virtual CPU */
2182#define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
2183#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
2184#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
2185#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
2186#define PF_DUMPCORE     0x00000200      /* dumped core */
2187#define PF_SIGNALED     0x00000400      /* killed by a signal */
2188#define PF_MEMALLOC     0x00000800      /* Allocating memory */
2189#define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
2190#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
2191#define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
2192#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
2193#define PF_FROZEN       0x00010000      /* frozen for system suspend */
2194#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
2195#define PF_KSWAPD       0x00040000      /* I am kswapd */
2196#define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
2197#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
2198#define PF_KTHREAD      0x00200000      /* I am a kernel thread */
2199#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
2200#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
2201#define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
2202#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
2203#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
2204#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
2205#define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
2206
2207/*
2208 * Only the _current_ task can read/write to tsk->flags, but other
2209 * tasks can access tsk->flags in readonly mode for example
2210 * with tsk_used_math (like during threaded core dumping).
2211 * There is however an exception to this rule during ptrace
2212 * or during fork: the ptracer task is allowed to write to the
2213 * child->flags of its traced child (same goes for fork, the parent
2214 * can write to the child->flags), because we're guaranteed the
2215 * child is not running and in turn not changing child->flags
2216 * at the same time the parent does it.
2217 */
2218#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2219#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2220#define clear_used_math() clear_stopped_child_used_math(current)
2221#define set_used_math() set_stopped_child_used_math(current)
2222#define conditional_stopped_child_used_math(condition, child) \
2223        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2224#define conditional_used_math(condition) \
2225        conditional_stopped_child_used_math(condition, current)
2226#define copy_to_stopped_child_used_math(child) \
2227        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2228/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2229#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2230#define used_math() tsk_used_math(current)
2231
2232/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2233 * __GFP_FS is also cleared as it implies __GFP_IO.
2234 */
2235static inline gfp_t memalloc_noio_flags(gfp_t flags)
2236{
2237        if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2238                flags &= ~(__GFP_IO | __GFP_FS);
2239        return flags;
2240}
2241
2242static inline unsigned int memalloc_noio_save(void)
2243{
2244        unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2245        current->flags |= PF_MEMALLOC_NOIO;
2246        return flags;
2247}
2248
2249static inline void memalloc_noio_restore(unsigned int flags)
2250{
2251        current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2252}
2253
2254/* Per-process atomic flags. */
2255#define PFA_NO_NEW_PRIVS 0      /* May not gain new privileges. */
2256#define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2257#define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2258#define PFA_LMK_WAITING  3      /* Lowmemorykiller is waiting */
2259
2260
2261#define TASK_PFA_TEST(name, func)                                       \
2262        static inline bool task_##func(struct task_struct *p)           \
2263        { return test_bit(PFA_##name, &p->atomic_flags); }
2264#define TASK_PFA_SET(name, func)                                        \
2265        static inline void task_set_##func(struct task_struct *p)       \
2266        { set_bit(PFA_##name, &p->atomic_flags); }
2267#define TASK_PFA_CLEAR(name, func)                                      \
2268        static inline void task_clear_##func(struct task_struct *p)     \
2269        { clear_bit(PFA_##name, &p->atomic_flags); }
2270
2271TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2272TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2273
2274TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2275TASK_PFA_SET(SPREAD_PAGE, spread_page)
2276TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2277
2278TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2279TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2280TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2281
2282TASK_PFA_TEST(LMK_WAITING, lmk_waiting)
2283TASK_PFA_SET(LMK_WAITING, lmk_waiting)
2284
2285/*
2286 * task->jobctl flags
2287 */
2288#define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
2289
2290#define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
2291#define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
2292#define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
2293#define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
2294#define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
2295#define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
2296#define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
2297
2298#define JOBCTL_STOP_DEQUEUED    (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2299#define JOBCTL_STOP_PENDING     (1UL << JOBCTL_STOP_PENDING_BIT)
2300#define JOBCTL_STOP_CONSUME     (1UL << JOBCTL_STOP_CONSUME_BIT)
2301#define JOBCTL_TRAP_STOP        (1UL << JOBCTL_TRAP_STOP_BIT)
2302#define JOBCTL_TRAP_NOTIFY      (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2303#define JOBCTL_TRAPPING         (1UL << JOBCTL_TRAPPING_BIT)
2304#define JOBCTL_LISTENING        (1UL << JOBCTL_LISTENING_BIT)
2305
2306#define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2307#define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2308
2309extern bool task_set_jobctl_pending(struct task_struct *task,
2310                                    unsigned long mask);
2311extern void task_clear_jobctl_trapping(struct task_struct *task);
2312extern void task_clear_jobctl_pending(struct task_struct *task,
2313                                      unsigned long mask);
2314
2315static inline void rcu_copy_process(struct task_struct *p)
2316{
2317#ifdef CONFIG_PREEMPT_RCU
2318        p->rcu_read_lock_nesting = 0;
2319        p->rcu_read_unlock_special.s = 0;
2320        p->rcu_blocked_node = NULL;
2321        INIT_LIST_HEAD(&p->rcu_node_entry);
2322#endif /* #ifdef CONFIG_PREEMPT_RCU */
2323#ifdef CONFIG_TASKS_RCU
2324        p->rcu_tasks_holdout = false;
2325        INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2326        p->rcu_tasks_idle_cpu = -1;
2327#endif /* #ifdef CONFIG_TASKS_RCU */
2328}
2329
2330static inline void tsk_restore_flags(struct task_struct *task,
2331                                unsigned long orig_flags, unsigned long flags)
2332{
2333        task->flags &= ~flags;
2334        task->flags |= orig_flags & flags;
2335}
2336
2337extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2338                                     const struct cpumask *trial);
2339extern int task_can_attach(struct task_struct *p,
2340                           const struct cpumask *cs_cpus_allowed);
2341#ifdef CONFIG_SMP
2342extern void do_set_cpus_allowed(struct task_struct *p,
2343                               const struct cpumask *new_mask);
2344
2345extern int set_cpus_allowed_ptr(struct task_struct *p,
2346                                const struct cpumask *new_mask);
2347#else
2348static inline void do_set_cpus_allowed(struct task_struct *p,
2349                                      const struct cpumask *new_mask)
2350{
2351}
2352static inline int set_cpus_allowed_ptr(struct task_struct *p,
2353                                       const struct cpumask *new_mask)
2354{
2355        if (!cpumask_test_cpu(0, new_mask))
2356                return -EINVAL;
2357        return 0;
2358}
2359#endif
2360
2361#ifdef CONFIG_NO_HZ_COMMON
2362void calc_load_enter_idle(void);
2363void calc_load_exit_idle(void);
2364#else
2365static inline void calc_load_enter_idle(void) { }
2366static inline void calc_load_exit_idle(void) { }
2367#endif /* CONFIG_NO_HZ_COMMON */
2368
2369/*
2370 * Do not use outside of architecture code which knows its limitations.
2371 *
2372 * sched_clock() has no promise of monotonicity or bounded drift between
2373 * CPUs, use (which you should not) requires disabling IRQs.
2374 *
2375 * Please use one of the three interfaces below.
2376 */
2377extern unsigned long long notrace sched_clock(void);
2378/*
2379 * See the comment in kernel/sched/clock.c
2380 */
2381extern u64 running_clock(void);
2382extern u64 sched_clock_cpu(int cpu);
2383
2384
2385extern void sched_clock_init(void);
2386
2387#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2388static inline void sched_clock_tick(void)
2389{
2390}
2391
2392static inline void sched_clock_idle_sleep_event(void)
2393{
2394}
2395
2396static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2397{
2398}
2399
2400static inline u64 cpu_clock(int cpu)
2401{
2402        return sched_clock();
2403}
2404
2405static inline u64 local_clock(void)
2406{
2407        return sched_clock();
2408}
2409#else
2410/*
2411 * Architectures can set this to 1 if they have specified
2412 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2413 * but then during bootup it turns out that sched_clock()
2414 * is reliable after all:
2415 */
2416extern int sched_clock_stable(void);
2417extern void set_sched_clock_stable(void);
2418extern void clear_sched_clock_stable(void);
2419
2420extern void sched_clock_tick(void);
2421extern void sched_clock_idle_sleep_event(void);
2422extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2423
2424/*
2425 * As outlined in clock.c, provides a fast, high resolution, nanosecond
2426 * time source that is monotonic per cpu argument and has bounded drift
2427 * between cpus.
2428 *
2429 * ######################### BIG FAT WARNING ##########################
2430 * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
2431 * # go backwards !!                                                  #
2432 * ####################################################################
2433 */
2434static inline u64 cpu_clock(int cpu)
2435{
2436        return sched_clock_cpu(cpu);
2437}
2438
2439static inline u64 local_clock(void)
2440{
2441        return sched_clock_cpu(raw_smp_processor_id());
2442}
2443#endif
2444
2445#ifdef CONFIG_IRQ_TIME_ACCOUNTING
2446/*
2447 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2448 * The reason for this explicit opt-in is not to have perf penalty with
2449 * slow sched_clocks.
2450 */
2451extern void enable_sched_clock_irqtime(void);
2452extern void disable_sched_clock_irqtime(void);
2453#else
2454static inline void enable_sched_clock_irqtime(void) {}
2455static inline void disable_sched_clock_irqtime(void) {}
2456#endif
2457
2458extern unsigned long long
2459task_sched_runtime(struct task_struct *task);
2460
2461/* sched_exec is called by processes performing an exec */
2462#ifdef CONFIG_SMP
2463extern void sched_exec(void);
2464#else
2465#define sched_exec()   {}
2466#endif
2467
2468extern void sched_clock_idle_sleep_event(void);
2469extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2470
2471#ifdef CONFIG_HOTPLUG_CPU
2472extern void idle_task_exit(void);
2473#else
2474static inline void idle_task_exit(void) {}
2475#endif
2476
2477#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2478extern void wake_up_nohz_cpu(int cpu);
2479#else
2480static inline void wake_up_nohz_cpu(int cpu) { }
2481#endif
2482
2483#ifdef CONFIG_NO_HZ_FULL
2484extern u64 scheduler_tick_max_deferment(void);
2485#endif
2486
2487#ifdef CONFIG_SCHED_AUTOGROUP
2488extern void sched_autogroup_create_attach(struct task_struct *p);
2489extern void sched_autogroup_detach(struct task_struct *p);
2490extern void sched_autogroup_fork(struct signal_struct *sig);
2491extern void sched_autogroup_exit(struct signal_struct *sig);
2492#ifdef CONFIG_PROC_FS
2493extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2494extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2495#endif
2496#else
2497static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2498static inline void sched_autogroup_detach(struct task_struct *p) { }
2499static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2500static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2501#endif
2502
2503extern int yield_to(struct task_struct *p, bool preempt);
2504extern void set_user_nice(struct task_struct *p, long nice);
2505extern int task_prio(const struct task_struct *p);
2506/**
2507 * task_nice - return the nice value of a given task.
2508 * @p: the task in question.
2509 *
2510 * Return: The nice value [ -20 ... 0 ... 19 ].
2511 */
2512static inline int task_nice(const struct task_struct *p)
2513{
2514        return PRIO_TO_NICE((p)->static_prio);
2515}
2516extern int can_nice(const struct task_struct *p, const int nice);
2517extern int task_curr(const struct task_struct *p);
2518extern int idle_cpu(int cpu);
2519extern int sched_setscheduler(struct task_struct *, int,
2520                              const struct sched_param *);
2521extern int sched_setscheduler_nocheck(struct task_struct *, int,
2522                                      const struct sched_param *);
2523extern int sched_setattr(struct task_struct *,
2524                         const struct sched_attr *);
2525extern struct task_struct *idle_task(int cpu);
2526/**
2527 * is_idle_task - is the specified task an idle task?
2528 * @p: the task in question.
2529 *
2530 * Return: 1 if @p is an idle task. 0 otherwise.
2531 */
2532static inline bool is_idle_task(const struct task_struct *p)
2533{
2534        return p->pid == 0;
2535}
2536extern struct task_struct *curr_task(int cpu);
2537extern void set_curr_task(int cpu, struct task_struct *p);
2538
2539void yield(void);
2540
2541union thread_union {
2542        struct thread_info thread_info;
2543        unsigned long stack[THREAD_SIZE/sizeof(long)];
2544};
2545
2546#ifndef __HAVE_ARCH_KSTACK_END
2547static inline int kstack_end(void *addr)
2548{
2549        /* Reliable end of stack detection:
2550         * Some APM bios versions misalign the stack
2551         */
2552        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2553}
2554#endif
2555
2556extern union thread_union init_thread_union;
2557extern struct task_struct init_task;
2558
2559extern struct   mm_struct init_mm;
2560
2561extern struct pid_namespace init_pid_ns;
2562
2563/*
2564 * find a task by one of its numerical ids
2565 *
2566 * find_task_by_pid_ns():
2567 *      finds a task by its pid in the specified namespace
2568 * find_task_by_vpid():
2569 *      finds a task by its virtual pid
2570 *
2571 * see also find_vpid() etc in include/linux/pid.h
2572 */
2573
2574extern struct task_struct *find_task_by_vpid(pid_t nr);
2575extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2576                struct pid_namespace *ns);
2577
2578/* per-UID process charging. */
2579extern struct user_struct * alloc_uid(kuid_t);
2580static inline struct user_struct *get_uid(struct user_struct *u)
2581{
2582        atomic_inc(&u->__count);
2583        return u;
2584}
2585extern void free_uid(struct user_struct *);
2586
2587#include <asm/current.h>
2588
2589extern void xtime_update(unsigned long ticks);
2590
2591extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2592extern int wake_up_process(struct task_struct *tsk);
2593extern void wake_up_new_task(struct task_struct *tsk);
2594#ifdef CONFIG_SMP
2595 extern void kick_process(struct task_struct *tsk);
2596#else
2597 static inline void kick_process(struct task_struct *tsk) { }
2598#endif
2599extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2600extern void sched_dead(struct task_struct *p);
2601
2602extern void proc_caches_init(void);
2603extern void flush_signals(struct task_struct *);
2604extern void ignore_signals(struct task_struct *);
2605extern void flush_signal_handlers(struct task_struct *, int force_default);
2606extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2607
2608static inline int kernel_dequeue_signal(siginfo_t *info)
2609{
2610        struct task_struct *tsk = current;
2611        siginfo_t __info;
2612        int ret;
2613
2614        spin_lock_irq(&tsk->sighand->siglock);
2615        ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
2616        spin_unlock_irq(&tsk->sighand->siglock);
2617
2618        return ret;
2619}
2620
2621static inline void kernel_signal_stop(void)
2622{
2623        spin_lock_irq(&current->sighand->siglock);
2624        if (current->jobctl & JOBCTL_STOP_DEQUEUED)
2625                __set_current_state(TASK_STOPPED);
2626        spin_unlock_irq(&current->sighand->siglock);
2627
2628        schedule();
2629}
2630
2631extern void release_task(struct task_struct * p);
2632extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2633extern int force_sigsegv(int, struct task_struct *);
2634extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2635extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2636extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2637extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2638                                const struct cred *, u32);
2639extern int kill_pgrp(struct pid *pid, int sig, int priv);
2640extern int kill_pid(struct pid *pid, int sig, int priv);
2641extern int kill_proc_info(int, struct siginfo *, pid_t);
2642extern __must_check bool do_notify_parent(struct task_struct *, int);
2643extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2644extern void force_sig(int, struct task_struct *);
2645extern int send_sig(int, struct task_struct *, int);
2646extern int zap_other_threads(struct task_struct *p);
2647extern struct sigqueue *sigqueue_alloc(void);
2648extern void sigqueue_free(struct sigqueue *);
2649extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2650extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2651
2652static inline void restore_saved_sigmask(void)
2653{
2654        if (test_and_clear_restore_sigmask())
2655                __set_current_blocked(&current->saved_sigmask);
2656}
2657
2658static inline sigset_t *sigmask_to_save(void)
2659{
2660        sigset_t *res = &current->blocked;
2661        if (unlikely(test_restore_sigmask()))
2662                res = &current->saved_sigmask;
2663        return res;
2664}
2665
2666static inline int kill_cad_pid(int sig, int priv)
2667{
2668        return kill_pid(cad_pid, sig, priv);
2669}
2670
2671/* These can be the second arg to send_sig_info/send_group_sig_info.  */
2672#define SEND_SIG_NOINFO ((struct siginfo *) 0)
2673#define SEND_SIG_PRIV   ((struct siginfo *) 1)
2674#define SEND_SIG_FORCED ((struct siginfo *) 2)
2675
2676/*
2677 * True if we are on the alternate signal stack.
2678 */
2679static inline int on_sig_stack(unsigned long sp)
2680{
2681        /*
2682         * If the signal stack is SS_AUTODISARM then, by construction, we
2683         * can't be on the signal stack unless user code deliberately set
2684         * SS_AUTODISARM when we were already on it.
2685         *
2686         * This improves reliability: if user state gets corrupted such that
2687         * the stack pointer points very close to the end of the signal stack,
2688         * then this check will enable the signal to be handled anyway.
2689         */
2690        if (current->sas_ss_flags & SS_AUTODISARM)
2691                return 0;
2692
2693#ifdef CONFIG_STACK_GROWSUP
2694        return sp >= current->sas_ss_sp &&
2695                sp - current->sas_ss_sp < current->sas_ss_size;
2696#else
2697        return sp > current->sas_ss_sp &&
2698                sp - current->sas_ss_sp <= current->sas_ss_size;
2699#endif
2700}
2701
2702static inline int sas_ss_flags(unsigned long sp)
2703{
2704        if (!current->sas_ss_size)
2705                return SS_DISABLE;
2706
2707        return on_sig_stack(sp) ? SS_ONSTACK : 0;
2708}
2709
2710static inline void sas_ss_reset(struct task_struct *p)
2711{
2712        p->sas_ss_sp = 0;
2713        p->sas_ss_size = 0;
2714        p->sas_ss_flags = SS_DISABLE;
2715}
2716
2717static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2718{
2719        if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2720#ifdef CONFIG_STACK_GROWSUP
2721                return current->sas_ss_sp;
2722#else
2723                return current->sas_ss_sp + current->sas_ss_size;
2724#endif
2725        return sp;
2726}
2727
2728/*
2729 * Routines for handling mm_structs
2730 */
2731extern struct mm_struct * mm_alloc(void);
2732
2733/* mmdrop drops the mm and the page tables */
2734extern void __mmdrop(struct mm_struct *);
2735static inline void mmdrop(struct mm_struct *mm)
2736{
2737        if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2738                __mmdrop(mm);
2739}
2740
2741static inline bool mmget_not_zero(struct mm_struct *mm)
2742{
2743        return atomic_inc_not_zero(&mm->mm_users);
2744}
2745
2746/* mmput gets rid of the mappings and all user-space */
2747extern void mmput(struct mm_struct *);
2748#ifdef CONFIG_MMU
2749/* same as above but performs the slow path from the async context. Can
2750 * be called from the atomic context as well
2751 */
2752extern void mmput_async(struct mm_struct *);
2753#endif
2754
2755/* Grab a reference to a task's mm, if it is not already going away */
2756extern struct mm_struct *get_task_mm(struct task_struct *task);
2757/*
2758 * Grab a reference to a task's mm, if it is not already going away
2759 * and ptrace_may_access with the mode parameter passed to it
2760 * succeeds.
2761 */
2762extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2763/* Remove the current tasks stale references to the old mm_struct */
2764extern void mm_release(struct task_struct *, struct mm_struct *);
2765
2766#ifdef CONFIG_HAVE_COPY_THREAD_TLS
2767extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2768                        struct task_struct *, unsigned long);
2769#else
2770extern int copy_thread(unsigned long, unsigned long, unsigned long,
2771                        struct task_struct *);
2772
2773/* Architectures that haven't opted into copy_thread_tls get the tls argument
2774 * via pt_regs, so ignore the tls argument passed via C. */
2775static inline int copy_thread_tls(
2776                unsigned long clone_flags, unsigned long sp, unsigned long arg,
2777                struct task_struct *p, unsigned long tls)
2778{
2779        return copy_thread(clone_flags, sp, arg, p);
2780}
2781#endif
2782extern void flush_thread(void);
2783
2784#ifdef CONFIG_HAVE_EXIT_THREAD
2785extern void exit_thread(struct task_struct *tsk);
2786#else
2787static inline void exit_thread(struct task_struct *tsk)
2788{
2789}
2790#endif
2791
2792extern void exit_files(struct task_struct *);
2793extern void __cleanup_sighand(struct sighand_struct *);
2794
2795extern void exit_itimers(struct signal_struct *);
2796extern void flush_itimer_signals(void);
2797
2798extern void do_group_exit(int);
2799
2800extern int do_execve(struct filename *,
2801                     const char __user * const __user *,
2802                     const char __user * const __user *);
2803extern int do_execveat(int, struct filename *,
2804                       const char __user * const __user *,
2805                       const char __user * const __user *,
2806                       int);
2807extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
2808extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2809struct task_struct *fork_idle(int);
2810extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2811
2812extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2813static inline void set_task_comm(struct task_struct *tsk, const char *from)
2814{
2815        __set_task_comm(tsk, from, false);
2816}
2817extern char *get_task_comm(char *to, struct task_struct *tsk);
2818
2819#ifdef CONFIG_SMP
2820void scheduler_ipi(void);
2821extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2822#else
2823static inline void scheduler_ipi(void) { }
2824static inline unsigned long wait_task_inactive(struct task_struct *p,
2825                                               long match_state)
2826{
2827        return 1;
2828}
2829#endif
2830
2831#define tasklist_empty() \
2832        list_empty(&init_task.tasks)
2833
2834#define next_task(p) \
2835        list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2836
2837#define for_each_process(p) \
2838        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2839
2840extern bool current_is_single_threaded(void);
2841
2842/*
2843 * Careful: do_each_thread/while_each_thread is a double loop so
2844 *          'break' will not work as expected - use goto instead.
2845 */
2846#define do_each_thread(g, t) \
2847        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2848
2849#define while_each_thread(g, t) \
2850        while ((t = next_thread(t)) != g)
2851
2852#define __for_each_thread(signal, t)    \
2853        list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2854
2855#define for_each_thread(p, t)           \
2856        __for_each_thread((p)->signal, t)
2857
2858/* Careful: this is a double loop, 'break' won't work as expected. */
2859#define for_each_process_thread(p, t)   \
2860        for_each_process(p) for_each_thread(p, t)
2861
2862static inline int get_nr_threads(struct task_struct *tsk)
2863{
2864        return tsk->signal->nr_threads;
2865}
2866
2867static inline bool thread_group_leader(struct task_struct *p)
2868{
2869        return p->exit_signal >= 0;
2870}
2871
2872/* Do to the insanities of de_thread it is possible for a process
2873 * to have the pid of the thread group leader without actually being
2874 * the thread group leader.  For iteration through the pids in proc
2875 * all we care about is that we have a task with the appropriate
2876 * pid, we don't actually care if we have the right task.
2877 */
2878static inline bool has_group_leader_pid(struct task_struct *p)
2879{
2880        return task_pid(p) == p->signal->leader_pid;
2881}
2882
2883static inline
2884bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2885{
2886        return p1->signal == p2->signal;
2887}
2888
2889static inline struct task_struct *next_thread(const struct task_struct *p)
2890{
2891        return list_entry_rcu(p->thread_group.next,
2892                              struct task_struct, thread_group);
2893}
2894
2895static inline int thread_group_empty(struct task_struct *p)
2896{
2897        return list_empty(&p->thread_group);
2898}
2899
2900#define delay_group_leader(p) \
2901                (thread_group_leader(p) && !thread_group_empty(p))
2902
2903/*
2904 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2905 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2906 * pins the final release of task.io_context.  Also protects ->cpuset and
2907 * ->cgroup.subsys[]. And ->vfork_done.
2908 *
2909 * Nests both inside and outside of read_lock(&tasklist_lock).
2910 * It must not be nested with write_lock_irq(&tasklist_lock),
2911 * neither inside nor outside.
2912 */
2913static inline void task_lock(struct task_struct *p)
2914{
2915        spin_lock(&p->alloc_lock);
2916}
2917
2918static inline void task_unlock(struct task_struct *p)
2919{
2920        spin_unlock(&p->alloc_lock);
2921}
2922
2923extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2924                                                        unsigned long *flags);
2925
2926static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2927                                                       unsigned long *flags)
2928{
2929        struct sighand_struct *ret;
2930
2931        ret = __lock_task_sighand(tsk, flags);
2932        (void)__cond_lock(&tsk->sighand->siglock, ret);
2933        return ret;
2934}
2935
2936static inline void unlock_task_sighand(struct task_struct *tsk,
2937                                                unsigned long *flags)
2938{
2939        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2940}
2941
2942/**
2943 * threadgroup_change_begin - mark the beginning of changes to a threadgroup
2944 * @tsk: task causing the changes
2945 *
2946 * All operations which modify a threadgroup - a new thread joining the
2947 * group, death of a member thread (the assertion of PF_EXITING) and
2948 * exec(2) dethreading the process and replacing the leader - are wrapped
2949 * by threadgroup_change_{begin|end}().  This is to provide a place which
2950 * subsystems needing threadgroup stability can hook into for
2951 * synchronization.
2952 */
2953static inline void threadgroup_change_begin(struct task_struct *tsk)
2954{
2955        might_sleep();
2956        cgroup_threadgroup_change_begin(tsk);
2957}
2958
2959/**
2960 * threadgroup_change_end - mark the end of changes to a threadgroup
2961 * @tsk: task causing the changes
2962 *
2963 * See threadgroup_change_begin().
2964 */
2965static inline void threadgroup_change_end(struct task_struct *tsk)
2966{
2967        cgroup_threadgroup_change_end(tsk);
2968}
2969
2970#ifndef __HAVE_THREAD_FUNCTIONS
2971
2972#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2973#define task_stack_page(task)   ((task)->stack)
2974
2975static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2976{
2977        *task_thread_info(p) = *task_thread_info(org);
2978        task_thread_info(p)->task = p;
2979}
2980
2981/*
2982 * Return the address of the last usable long on the stack.
2983 *
2984 * When the stack grows down, this is just above the thread
2985 * info struct. Going any lower will corrupt the threadinfo.
2986 *
2987 * When the stack grows up, this is the highest address.
2988 * Beyond that position, we corrupt data on the next page.
2989 */
2990static inline unsigned long *end_of_stack(struct task_struct *p)
2991{
2992#ifdef CONFIG_STACK_GROWSUP
2993        return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2994#else
2995        return (unsigned long *)(task_thread_info(p) + 1);
2996#endif
2997}
2998
2999#endif
3000#define task_stack_end_corrupted(task) \
3001                (*(end_of_stack(task)) != STACK_END_MAGIC)
3002
3003static inline int object_is_on_stack(void *obj)
3004{
3005        void *stack = task_stack_page(current);
3006
3007        return (obj >= stack) && (obj < (stack + THREAD_SIZE));
3008}
3009
3010extern void thread_stack_cache_init(void);
3011
3012#ifdef CONFIG_DEBUG_STACK_USAGE
3013static inline unsigned long stack_not_used(struct task_struct *p)
3014{
3015        unsigned long *n = end_of_stack(p);
3016
3017        do {    /* Skip over canary */
3018# ifdef CONFIG_STACK_GROWSUP
3019                n--;
3020# else
3021                n++;
3022# endif
3023        } while (!*n);
3024
3025# ifdef CONFIG_STACK_GROWSUP
3026        return (unsigned long)end_of_stack(p) - (unsigned long)n;
3027# else
3028        return (unsigned long)n - (unsigned long)end_of_stack(p);
3029# endif
3030}
3031#endif
3032extern void set_task_stack_end_magic(struct task_struct *tsk);
3033
3034/* set thread flags in other task's structures
3035 * - see asm/thread_info.h for TIF_xxxx flags available
3036 */
3037static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
3038{
3039        set_ti_thread_flag(task_thread_info(tsk), flag);
3040}
3041
3042static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3043{
3044        clear_ti_thread_flag(task_thread_info(tsk), flag);
3045}
3046
3047static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
3048{
3049        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
3050}
3051
3052static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3053{
3054        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
3055}
3056
3057static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
3058{
3059        return test_ti_thread_flag(task_thread_info(tsk), flag);
3060}
3061
3062static inline void set_tsk_need_resched(struct task_struct *tsk)
3063{
3064        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3065}
3066
3067static inline void clear_tsk_need_resched(struct task_struct *tsk)
3068{
3069        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3070}
3071
3072static inline int test_tsk_need_resched(struct task_struct *tsk)
3073{
3074        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
3075}
3076
3077static inline int restart_syscall(void)
3078{
3079        set_tsk_thread_flag(current, TIF_SIGPENDING);
3080        return -ERESTARTNOINTR;
3081}
3082
3083static inline int signal_pending(struct task_struct *p)
3084{
3085        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
3086}
3087
3088static inline int __fatal_signal_pending(struct task_struct *p)
3089{
3090        return unlikely(sigismember(&p->pending.signal, SIGKILL));
3091}
3092
3093static inline int fatal_signal_pending(struct task_struct *p)
3094{
3095        return signal_pending(p) && __fatal_signal_pending(p);
3096}
3097
3098static inline int signal_pending_state(long state, struct task_struct *p)
3099{
3100        if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
3101                return 0;
3102        if (!signal_pending(p))
3103                return 0;
3104
3105        return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
3106}
3107
3108/*
3109 * cond_resched() and cond_resched_lock(): latency reduction via
3110 * explicit rescheduling in places that are safe. The return
3111 * value indicates whether a reschedule was done in fact.
3112 * cond_resched_lock() will drop the spinlock before scheduling,
3113 * cond_resched_softirq() will enable bhs before scheduling.
3114 */
3115extern int _cond_resched(void);
3116
3117#define cond_resched() ({                       \
3118        ___might_sleep(__FILE__, __LINE__, 0);  \
3119        _cond_resched();                        \
3120})
3121
3122extern int __cond_resched_lock(spinlock_t *lock);
3123
3124#define cond_resched_lock(lock) ({                              \
3125        ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
3126        __cond_resched_lock(lock);                              \
3127})
3128
3129extern int __cond_resched_softirq(void);
3130
3131#define cond_resched_softirq() ({                                       \
3132        ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
3133        __cond_resched_softirq();                                       \
3134})
3135
3136static inline void cond_resched_rcu(void)
3137{
3138#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
3139        rcu_read_unlock();
3140        cond_resched();
3141        rcu_read_lock();
3142#endif
3143}
3144
3145/*
3146 * Does a critical section need to be broken due to another
3147 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
3148 * but a general need for low latency)
3149 */
3150static inline int spin_needbreak(spinlock_t *lock)
3151{
3152#ifdef CONFIG_PREEMPT
3153        return spin_is_contended(lock);
3154#else
3155        return 0;
3156#endif
3157}
3158
3159/*
3160 * Idle thread specific functions to determine the need_resched
3161 * polling state.
3162 */
3163#ifdef TIF_POLLING_NRFLAG
3164static inline int tsk_is_polling(struct task_struct *p)
3165{
3166        return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
3167}
3168
3169static inline void __current_set_polling(void)
3170{
3171        set_thread_flag(TIF_POLLING_NRFLAG);
3172}
3173
3174static inline bool __must_check current_set_polling_and_test(void)
3175{
3176        __current_set_polling();
3177
3178        /*
3179         * Polling state must be visible before we test NEED_RESCHED,
3180         * paired by resched_curr()
3181         */
3182        smp_mb__after_atomic();
3183
3184        return unlikely(tif_need_resched());
3185}
3186
3187static inline void __current_clr_polling(void)
3188{
3189        clear_thread_flag(TIF_POLLING_NRFLAG);
3190}
3191
3192static inline bool __must_check current_clr_polling_and_test(void)
3193{
3194        __current_clr_polling();
3195
3196        /*
3197         * Polling state must be visible before we test NEED_RESCHED,
3198         * paired by resched_curr()
3199         */
3200        smp_mb__after_atomic();
3201
3202        return unlikely(tif_need_resched());
3203}
3204
3205#else
3206static inline int tsk_is_polling(struct task_struct *p) { return 0; }
3207static inline void __current_set_polling(void) { }
3208static inline void __current_clr_polling(void) { }
3209
3210static inline bool __must_check current_set_polling_and_test(void)
3211{
3212        return unlikely(tif_need_resched());
3213}
3214static inline bool __must_check current_clr_polling_and_test(void)
3215{
3216        return unlikely(tif_need_resched());
3217}
3218#endif
3219
3220static inline void current_clr_polling(void)
3221{
3222        __current_clr_polling();
3223
3224        /*
3225         * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3226         * Once the bit is cleared, we'll get IPIs with every new
3227         * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3228         * fold.
3229         */
3230        smp_mb(); /* paired with resched_curr() */
3231
3232        preempt_fold_need_resched();
3233}
3234
3235static __always_inline bool need_resched(void)
3236{
3237        return unlikely(tif_need_resched());
3238}
3239
3240/*
3241 * Thread group CPU time accounting.
3242 */
3243void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3244void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3245
3246/*
3247 * Reevaluate whether the task has signals pending delivery.
3248 * Wake the task if so.
3249 * This is required every time the blocked sigset_t changes.
3250 * callers must hold sighand->siglock.
3251 */
3252extern void recalc_sigpending_and_wake(struct task_struct *t);
3253extern void recalc_sigpending(void);
3254
3255extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3256
3257static inline void signal_wake_up(struct task_struct *t, bool resume)
3258{
3259        signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3260}
3261static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3262{
3263        signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3264}
3265
3266/*
3267 * Wrappers for p->thread_info->cpu access. No-op on UP.
3268 */
3269#ifdef CONFIG_SMP
3270
3271static inline unsigned int task_cpu(const struct task_struct *p)
3272{
3273        return task_thread_info(p)->cpu;
3274}
3275
3276static inline int task_node(const struct task_struct *p)
3277{
3278        return cpu_to_node(task_cpu(p));
3279}
3280
3281extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3282
3283#else
3284
3285static inline unsigned int task_cpu(const struct task_struct *p)
3286{
3287        return 0;
3288}
3289
3290static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3291{
3292}
3293
3294#endif /* CONFIG_SMP */
3295
3296extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3297extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3298
3299#ifdef CONFIG_CGROUP_SCHED
3300extern struct task_group root_task_group;
3301#endif /* CONFIG_CGROUP_SCHED */
3302
3303extern int task_can_switch_user(struct user_struct *up,
3304                                        struct task_struct *tsk);
3305
3306#ifdef CONFIG_TASK_XACCT
3307static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3308{
3309        tsk->ioac.rchar += amt;
3310}
3311
3312static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3313{
3314        tsk->ioac.wchar += amt;
3315}
3316
3317static inline void inc_syscr(struct task_struct *tsk)
3318{
3319        tsk->ioac.syscr++;
3320}
3321
3322static inline void inc_syscw(struct task_struct *tsk)
3323{
3324        tsk->ioac.syscw++;
3325}
3326#else
3327static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3328{
3329}
3330
3331static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3332{
3333}
3334
3335static inline void inc_syscr(struct task_struct *tsk)
3336{
3337}
3338
3339static inline void inc_syscw(struct task_struct *tsk)
3340{
3341}
3342#endif
3343
3344#ifndef TASK_SIZE_OF
3345#define TASK_SIZE_OF(tsk)       TASK_SIZE
3346#endif
3347
3348#ifdef CONFIG_MEMCG
3349extern void mm_update_next_owner(struct mm_struct *mm);
3350#else
3351static inline void mm_update_next_owner(struct mm_struct *mm)
3352{
3353}
3354#endif /* CONFIG_MEMCG */
3355
3356static inline unsigned long task_rlimit(const struct task_struct *tsk,
3357                unsigned int limit)
3358{
3359        return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3360}
3361
3362static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3363                unsigned int limit)
3364{
3365        return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3366}
3367
3368static inline unsigned long rlimit(unsigned int limit)
3369{
3370        return task_rlimit(current, limit);
3371}
3372
3373static inline unsigned long rlimit_max(unsigned int limit)
3374{
3375        return task_rlimit_max(current, limit);
3376}
3377
3378#ifdef CONFIG_CPU_FREQ
3379struct update_util_data {
3380        void (*func)(struct update_util_data *data,
3381                     u64 time, unsigned long util, unsigned long max);
3382};
3383
3384void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
3385                        void (*func)(struct update_util_data *data, u64 time,
3386                                     unsigned long util, unsigned long max));
3387void cpufreq_remove_update_util_hook(int cpu);
3388#endif /* CONFIG_CPU_FREQ */
3389
3390#endif
3391
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