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_NEW                2048
 223#define TASK_STATE_MAX          4096
 224
 225#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
 226
 227extern char ___assert_task_state[1 - 2*!!(
 228                sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
 229
 230/* Convenience macros for the sake of set_task_state */
 231#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 232#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
 233#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 234
 235#define TASK_IDLE               (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 236
 237/* Convenience macros for the sake of wake_up */
 238#define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 239#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 240
 241/* get_task_state() */
 242#define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 243                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 244                                 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
 245
 246#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
 247#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 248#define task_is_stopped_or_traced(task) \
 249                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 250#define task_contributes_to_load(task)  \
 251                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 252                                 (task->flags & PF_FROZEN) == 0 && \
 253                                 (task->state & TASK_NOLOAD) == 0)
 254
 255#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 256
 257#define __set_task_state(tsk, state_value)                      \
 258        do {                                                    \
 259                (tsk)->task_state_change = _THIS_IP_;           \
 260                (tsk)->state = (state_value);                   \
 261        } while (0)
 262#define set_task_state(tsk, state_value)                        \
 263        do {                                                    \
 264                (tsk)->task_state_change = _THIS_IP_;           \
 265                smp_store_mb((tsk)->state, (state_value));      \
 266        } while (0)
 267
 268#define __set_current_state(state_value)                        \
 269        do {                                                    \
 270                current->task_state_change = _THIS_IP_;         \
 271                current->state = (state_value);                 \
 272        } while (0)
 273#define set_current_state(state_value)                          \
 274        do {                                                    \
 275                current->task_state_change = _THIS_IP_;         \
 276                smp_store_mb(current->state, (state_value));    \
 277        } while (0)
 278
 279#else
 280
 281/*
 282 * @tsk had better be current, or you get to keep the pieces.
 283 *
 284 * The only reason is that computing current can be more expensive than
 285 * using a pointer that's already available.
 286 *
 287 * Therefore, see set_current_state().
 288 */
 289#define __set_task_state(tsk, state_value)              \
 290        do { (tsk)->state = (state_value); } while (0)
 291#define set_task_state(tsk, state_value)                \
 292        smp_store_mb((tsk)->state, (state_value))
 293
 294/*
 295 * set_current_state() includes a barrier so that the write of current->state
 296 * is correctly serialised wrt the caller's subsequent test of whether to
 297 * actually sleep:
 298 *
 299 *   for (;;) {
 300 *      set_current_state(TASK_UNINTERRUPTIBLE);
 301 *      if (!need_sleep)
 302 *              break;
 303 *
 304 *      schedule();
 305 *   }
 306 *   __set_current_state(TASK_RUNNING);
 307 *
 308 * If the caller does not need such serialisation (because, for instance, the
 309 * condition test and condition change and wakeup are under the same lock) then
 310 * use __set_current_state().
 311 *
 312 * The above is typically ordered against the wakeup, which does:
 313 *
 314 *      need_sleep = false;
 315 *      wake_up_state(p, TASK_UNINTERRUPTIBLE);
 316 *
 317 * Where wake_up_state() (and all other wakeup primitives) imply enough
 318 * barriers to order the store of the variable against wakeup.
 319 *
 320 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
 321 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
 322 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
 323 *
 324 * This is obviously fine, since they both store the exact same value.
 325 *
 326 * Also see the comments of try_to_wake_up().
 327 */
 328#define __set_current_state(state_value)                \
 329        do { current->state = (state_value); } while (0)
 330#define set_current_state(state_value)                  \
 331        smp_store_mb(current->state, (state_value))
 332
 333#endif
 334
 335/* Task command name length */
 336#define TASK_COMM_LEN 16
 337
 338#include <linux/spinlock.h>
 339
 340/*
 341 * This serializes "schedule()" and also protects
 342 * the run-queue from deletions/modifications (but
 343 * _adding_ to the beginning of the run-queue has
 344 * a separate lock).
 345 */
 346extern rwlock_t tasklist_lock;
 347extern spinlock_t mmlist_lock;
 348
 349struct task_struct;
 350
 351#ifdef CONFIG_PROVE_RCU
 352extern int lockdep_tasklist_lock_is_held(void);
 353#endif /* #ifdef CONFIG_PROVE_RCU */
 354
 355extern void sched_init(void);
 356extern void sched_init_smp(void);
 357extern asmlinkage void schedule_tail(struct task_struct *prev);
 358extern void init_idle(struct task_struct *idle, int cpu);
 359extern void init_idle_bootup_task(struct task_struct *idle);
 360
 361extern cpumask_var_t cpu_isolated_map;
 362
 363extern int runqueue_is_locked(int cpu);
 364
 365#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 366extern void nohz_balance_enter_idle(int cpu);
 367extern void set_cpu_sd_state_idle(void);
 368extern int get_nohz_timer_target(void);
 369#else
 370static inline void nohz_balance_enter_idle(int cpu) { }
 371static inline void set_cpu_sd_state_idle(void) { }
 372#endif
 373
 374/*
 375 * Only dump TASK_* tasks. (0 for all tasks)
 376 */
 377extern void show_state_filter(unsigned long state_filter);
 378
 379static inline void show_state(void)
 380{
 381        show_state_filter(0);
 382}
 383
 384extern void show_regs(struct pt_regs *);
 385
 386/*
 387 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 388 * task), SP is the stack pointer of the first frame that should be shown in the back
 389 * trace (or NULL if the entire call-chain of the task should be shown).
 390 */
 391extern void show_stack(struct task_struct *task, unsigned long *sp);
 392
 393extern void cpu_init (void);
 394extern void trap_init(void);
 395extern void update_process_times(int user);
 396extern void scheduler_tick(void);
 397extern int sched_cpu_starting(unsigned int cpu);
 398extern int sched_cpu_activate(unsigned int cpu);
 399extern int sched_cpu_deactivate(unsigned int cpu);
 400
 401#ifdef CONFIG_HOTPLUG_CPU
 402extern int sched_cpu_dying(unsigned int cpu);
 403#else
 404# define sched_cpu_dying        NULL
 405#endif
 406
 407extern void sched_show_task(struct task_struct *p);
 408
 409#ifdef CONFIG_LOCKUP_DETECTOR
 410extern void touch_softlockup_watchdog_sched(void);
 411extern void touch_softlockup_watchdog(void);
 412extern void touch_softlockup_watchdog_sync(void);
 413extern void touch_all_softlockup_watchdogs(void);
 414extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
 415                                  void __user *buffer,
 416                                  size_t *lenp, loff_t *ppos);
 417extern unsigned int  softlockup_panic;
 418extern unsigned int  hardlockup_panic;
 419void lockup_detector_init(void);
 420#else
 421static inline void touch_softlockup_watchdog_sched(void)
 422{
 423}
 424static inline void touch_softlockup_watchdog(void)
 425{
 426}
 427static inline void touch_softlockup_watchdog_sync(void)
 428{
 429}
 430static inline void touch_all_softlockup_watchdogs(void)
 431{
 432}
 433static inline void lockup_detector_init(void)
 434{
 435}
 436#endif
 437
 438#ifdef CONFIG_DETECT_HUNG_TASK
 439void reset_hung_task_detector(void);
 440#else
 441static inline void reset_hung_task_detector(void)
 442{
 443}
 444#endif
 445
 446/* Attach to any functions which should be ignored in wchan output. */
 447#define __sched         __attribute__((__section__(".sched.text")))
 448
 449/* Linker adds these: start and end of __sched functions */
 450extern char __sched_text_start[], __sched_text_end[];
 451
 452/* Is this address in the __sched functions? */
 453extern int in_sched_functions(unsigned long addr);
 454
 455#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 456extern signed long schedule_timeout(signed long timeout);
 457extern signed long schedule_timeout_interruptible(signed long timeout);
 458extern signed long schedule_timeout_killable(signed long timeout);
 459extern signed long schedule_timeout_uninterruptible(signed long timeout);
 460extern signed long schedule_timeout_idle(signed long timeout);
 461asmlinkage void schedule(void);
 462extern void schedule_preempt_disabled(void);
 463
 464extern long io_schedule_timeout(long timeout);
 465
 466static inline void io_schedule(void)
 467{
 468        io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
 469}
 470
 471void __noreturn do_task_dead(void);
 472
 473struct nsproxy;
 474struct user_namespace;
 475
 476#ifdef CONFIG_MMU
 477extern void arch_pick_mmap_layout(struct mm_struct *mm);
 478extern unsigned long
 479arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 480                       unsigned long, unsigned long);
 481extern unsigned long
 482arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 483                          unsigned long len, unsigned long pgoff,
 484                          unsigned long flags);
 485#else
 486static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
 487#endif
 488
 489#define SUID_DUMP_DISABLE       0       /* No setuid dumping */
 490#define SUID_DUMP_USER          1       /* Dump as user of process */
 491#define SUID_DUMP_ROOT          2       /* Dump as root */
 492
 493/* mm flags */
 494
 495/* for SUID_DUMP_* above */
 496#define MMF_DUMPABLE_BITS 2
 497#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
 498
 499extern void set_dumpable(struct mm_struct *mm, int value);
 500/*
 501 * This returns the actual value of the suid_dumpable flag. For things
 502 * that are using this for checking for privilege transitions, it must
 503 * test against SUID_DUMP_USER rather than treating it as a boolean
 504 * value.
 505 */
 506static inline int __get_dumpable(unsigned long mm_flags)
 507{
 508        return mm_flags & MMF_DUMPABLE_MASK;
 509}
 510
 511static inline int get_dumpable(struct mm_struct *mm)
 512{
 513        return __get_dumpable(mm->flags);
 514}
 515
 516/* coredump filter bits */
 517#define MMF_DUMP_ANON_PRIVATE   2
 518#define MMF_DUMP_ANON_SHARED    3
 519#define MMF_DUMP_MAPPED_PRIVATE 4
 520#define MMF_DUMP_MAPPED_SHARED  5
 521#define MMF_DUMP_ELF_HEADERS    6
 522#define MMF_DUMP_HUGETLB_PRIVATE 7
 523#define MMF_DUMP_HUGETLB_SHARED  8
 524#define MMF_DUMP_DAX_PRIVATE    9
 525#define MMF_DUMP_DAX_SHARED     10
 526
 527#define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
 528#define MMF_DUMP_FILTER_BITS    9
 529#define MMF_DUMP_FILTER_MASK \
 530        (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 531#define MMF_DUMP_FILTER_DEFAULT \
 532        ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
 533         (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
 534
 535#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
 536# define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
 537#else
 538# define MMF_DUMP_MASK_DEFAULT_ELF      0
 539#endif
 540                                        /* leave room for more dump flags */
 541#define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
 542#define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
 543/*
 544 * This one-shot flag is dropped due to necessity of changing exe once again
 545 * on NFS restore
 546 */
 547//#define MMF_EXE_FILE_CHANGED  18      /* see prctl_set_mm_exe_file() */
 548
 549#define MMF_HAS_UPROBES         19      /* has uprobes */
 550#define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
 551#define MMF_OOM_SKIP            21      /* mm is of no interest for the OOM killer */
 552#define MMF_UNSTABLE            22      /* mm is unstable for copy_from_user */
 553#define MMF_HUGE_ZERO_PAGE      23      /* mm has ever used the global huge zero page */
 554
 555#define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
 556
 557struct sighand_struct {
 558        atomic_t                count;
 559        struct k_sigaction      action[_NSIG];
 560        spinlock_t              siglock;
 561        wait_queue_head_t       signalfd_wqh;
 562};
 563
 564struct pacct_struct {
 565        int                     ac_flag;
 566        long                    ac_exitcode;
 567        unsigned long           ac_mem;
 568        cputime_t               ac_utime, ac_stime;
 569        unsigned long           ac_minflt, ac_majflt;
 570};
 571
 572struct cpu_itimer {
 573        cputime_t expires;
 574        cputime_t incr;
 575        u32 error;
 576        u32 incr_error;
 577};
 578
 579/**
 580 * struct prev_cputime - snaphsot of system and user cputime
 581 * @utime: time spent in user mode
 582 * @stime: time spent in system mode
 583 * @lock: protects the above two fields
 584 *
 585 * Stores previous user/system time values such that we can guarantee
 586 * monotonicity.
 587 */
 588struct prev_cputime {
 589#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 590        cputime_t utime;
 591        cputime_t stime;
 592        raw_spinlock_t lock;
 593#endif
 594};
 595
 596static inline void prev_cputime_init(struct prev_cputime *prev)
 597{
 598#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 599        prev->utime = prev->stime = 0;
 600        raw_spin_lock_init(&prev->lock);
 601#endif
 602}
 603
 604/**
 605 * struct task_cputime - collected CPU time counts
 606 * @utime:              time spent in user mode, in &cputime_t units
 607 * @stime:              time spent in kernel mode, in &cputime_t units
 608 * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
 609 *
 610 * This structure groups together three kinds of CPU time that are tracked for
 611 * threads and thread groups.  Most things considering CPU time want to group
 612 * these counts together and treat all three of them in parallel.
 613 */
 614struct task_cputime {
 615        cputime_t utime;
 616        cputime_t stime;
 617        unsigned long long sum_exec_runtime;
 618};
 619
 620/* Alternate field names when used to cache expirations. */
 621#define virt_exp        utime
 622#define prof_exp        stime
 623#define sched_exp       sum_exec_runtime
 624
 625#define INIT_CPUTIME    \
 626        (struct task_cputime) {                                 \
 627                .utime = 0,                                     \
 628                .stime = 0,                                     \
 629                .sum_exec_runtime = 0,                          \
 630        }
 631
 632/*
 633 * This is the atomic variant of task_cputime, which can be used for
 634 * storing and updating task_cputime statistics without locking.
 635 */
 636struct task_cputime_atomic {
 637        atomic64_t utime;
 638        atomic64_t stime;
 639        atomic64_t sum_exec_runtime;
 640};
 641
 642#define INIT_CPUTIME_ATOMIC \
 643        (struct task_cputime_atomic) {                          \
 644                .utime = ATOMIC64_INIT(0),                      \
 645                .stime = ATOMIC64_INIT(0),                      \
 646                .sum_exec_runtime = ATOMIC64_INIT(0),           \
 647        }
 648
 649#define PREEMPT_DISABLED        (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
 650
 651/*
 652 * Disable preemption until the scheduler is running -- use an unconditional
 653 * value so that it also works on !PREEMPT_COUNT kernels.
 654 *
 655 * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
 656 */
 657#define INIT_PREEMPT_COUNT      PREEMPT_OFFSET
 658
 659/*
 660 * Initial preempt_count value; reflects the preempt_count schedule invariant
 661 * which states that during context switches:
 662 *
 663 *    preempt_count() == 2*PREEMPT_DISABLE_OFFSET
 664 *
 665 * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
 666 * Note: See finish_task_switch().
 667 */
 668#define FORK_PREEMPT_COUNT      (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
 669
 670/**
 671 * struct thread_group_cputimer - thread group interval timer counts
 672 * @cputime_atomic:     atomic thread group interval timers.
 673 * @running:            true when there are timers running and
 674 *                      @cputime_atomic receives updates.
 675 * @checking_timer:     true when a thread in the group is in the
 676 *                      process of checking for thread group timers.
 677 *
 678 * This structure contains the version of task_cputime, above, that is
 679 * used for thread group CPU timer calculations.
 680 */
 681struct thread_group_cputimer {
 682        struct task_cputime_atomic cputime_atomic;
 683        bool running;
 684        bool checking_timer;
 685};
 686
 687#include <linux/rwsem.h>
 688struct autogroup;
 689
 690/*
 691 * NOTE! "signal_struct" does not have its own
 692 * locking, because a shared signal_struct always
 693 * implies a shared sighand_struct, so locking
 694 * sighand_struct is always a proper superset of
 695 * the locking of signal_struct.
 696 */
 697struct signal_struct {
 698        atomic_t                sigcnt;
 699        atomic_t                live;
 700        int                     nr_threads;
 701        struct list_head        thread_head;
 702
 703        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 704
 705        /* current thread group signal load-balancing target: */
 706        struct task_struct      *curr_target;
 707
 708        /* shared signal handling: */
 709        struct sigpending       shared_pending;
 710
 711        /* thread group exit support */
 712        int                     group_exit_code;
 713        /* overloaded:
 714         * - notify group_exit_task when ->count is equal to notify_count
 715         * - everyone except group_exit_task is stopped during signal delivery
 716         *   of fatal signals, group_exit_task processes the signal.
 717         */
 718        int                     notify_count;
 719        struct task_struct      *group_exit_task;
 720
 721        /* thread group stop support, overloads group_exit_code too */
 722        int                     group_stop_count;
 723        unsigned int            flags; /* see SIGNAL_* flags below */
 724
 725        /*
 726         * PR_SET_CHILD_SUBREAPER marks a process, like a service
 727         * manager, to re-parent orphan (double-forking) child processes
 728         * to this process instead of 'init'. The service manager is
 729         * able to receive SIGCHLD signals and is able to investigate
 730         * the process until it calls wait(). All children of this
 731         * process will inherit a flag if they should look for a
 732         * child_subreaper process at exit.
 733         */
 734        unsigned int            is_child_subreaper:1;
 735        unsigned int            has_child_subreaper:1;
 736
 737        /* POSIX.1b Interval Timers */
 738        int                     posix_timer_id;
 739        struct list_head        posix_timers;
 740
 741        /* ITIMER_REAL timer for the process */
 742        struct hrtimer real_timer;
 743        struct pid *leader_pid;
 744        ktime_t it_real_incr;
 745
 746        /*
 747         * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
 748         * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
 749         * values are defined to 0 and 1 respectively
 750         */
 751        struct cpu_itimer it[2];
 752
 753        /*
 754         * Thread group totals for process CPU timers.
 755         * See thread_group_cputimer(), et al, for details.
 756         */
 757        struct thread_group_cputimer cputimer;
 758
 759        /* Earliest-expiration cache. */
 760        struct task_cputime cputime_expires;
 761
 762#ifdef CONFIG_NO_HZ_FULL
 763        atomic_t tick_dep_mask;
 764#endif
 765
 766        struct list_head cpu_timers[3];
 767
 768        struct pid *tty_old_pgrp;
 769
 770        /* boolean value for session group leader */
 771        int leader;
 772
 773        struct tty_struct *tty; /* NULL if no tty */
 774
 775#ifdef CONFIG_SCHED_AUTOGROUP
 776        struct autogroup *autogroup;
 777#endif
 778        /*
 779         * Cumulative resource counters for dead threads in the group,
 780         * and for reaped dead child processes forked by this group.
 781         * Live threads maintain their own counters and add to these
 782         * in __exit_signal, except for the group leader.
 783         */
 784        seqlock_t stats_lock;
 785        cputime_t utime, stime, cutime, cstime;
 786        cputime_t gtime;
 787        cputime_t cgtime;
 788        struct prev_cputime prev_cputime;
 789        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 790        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 791        unsigned long inblock, oublock, cinblock, coublock;
 792        unsigned long maxrss, cmaxrss;
 793        struct task_io_accounting ioac;
 794
 795        /*
 796         * Cumulative ns of schedule CPU time fo dead threads in the
 797         * group, not including a zombie group leader, (This only differs
 798         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 799         * other than jiffies.)
 800         */
 801        unsigned long long sum_sched_runtime;
 802
 803        /*
 804         * We don't bother to synchronize most readers of this at all,
 805         * because there is no reader checking a limit that actually needs
 806         * to get both rlim_cur and rlim_max atomically, and either one
 807         * alone is a single word that can safely be read normally.
 808         * getrlimit/setrlimit use task_lock(current->group_leader) to
 809         * protect this instead of the siglock, because they really
 810         * have no need to disable irqs.
 811         */
 812        struct rlimit rlim[RLIM_NLIMITS];
 813
 814#ifdef CONFIG_BSD_PROCESS_ACCT
 815        struct pacct_struct pacct;      /* per-process accounting information */
 816#endif
 817#ifdef CONFIG_TASKSTATS
 818        struct taskstats *stats;
 819#endif
 820#ifdef CONFIG_AUDIT
 821        unsigned audit_tty;
 822        struct tty_audit_buf *tty_audit_buf;
 823#endif
 824
 825        /*
 826         * Thread is the potential origin of an oom condition; kill first on
 827         * oom
 828         */
 829        bool oom_flag_origin;
 830        short oom_score_adj;            /* OOM kill score adjustment */
 831        short oom_score_adj_min;        /* OOM kill score adjustment min value.
 832                                         * Only settable by CAP_SYS_RESOURCE. */
 833        struct mm_struct *oom_mm;       /* recorded mm when the thread group got
 834                                         * killed by the oom killer */
 835
 836        struct mutex cred_guard_mutex;  /* guard against foreign influences on
 837                                         * credential calculations
 838                                         * (notably. ptrace) */
 839};
 840
 841/*
 842 * Bits in flags field of signal_struct.
 843 */
 844#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 845#define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
 846#define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
 847#define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
 848/*
 849 * Pending notifications to parent.
 850 */
 851#define SIGNAL_CLD_STOPPED      0x00000010
 852#define SIGNAL_CLD_CONTINUED    0x00000020
 853#define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
 854
 855#define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
 856
 857#define SIGNAL_STOP_MASK (SIGNAL_CLD_MASK | SIGNAL_STOP_STOPPED | \
 858                          SIGNAL_STOP_CONTINUED)
 859
 860static inline void signal_set_stop_flags(struct signal_struct *sig,
 861                                         unsigned int flags)
 862{
 863        WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP));
 864        sig->flags = (sig->flags & ~SIGNAL_STOP_MASK) | flags;
 865}
 866
 867/* If true, all threads except ->group_exit_task have pending SIGKILL */
 868static inline int signal_group_exit(const struct signal_struct *sig)
 869{
 870        return  (sig->flags & SIGNAL_GROUP_EXIT) ||
 871                (sig->group_exit_task != NULL);
 872}
 873
 874/*
 875 * Some day this will be a full-fledged user tracking system..
 876 */
 877struct user_struct {
 878        atomic_t __count;       /* reference count */
 879        atomic_t processes;     /* How many processes does this user have? */
 880        atomic_t sigpending;    /* How many pending signals does this user have? */
 881#ifdef CONFIG_INOTIFY_USER
 882        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 883        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 884#endif
 885#ifdef CONFIG_FANOTIFY
 886        atomic_t fanotify_listeners;
 887#endif
 888#ifdef CONFIG_EPOLL
 889        atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
 890#endif
 891#ifdef CONFIG_POSIX_MQUEUE
 892        /* protected by mq_lock */
 893        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 894#endif
 895        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 896        unsigned long unix_inflight;    /* How many files in flight in unix sockets */
 897        atomic_long_t pipe_bufs;  /* how many pages are allocated in pipe buffers */
 898
 899#ifdef CONFIG_KEYS
 900        struct key *uid_keyring;        /* UID specific keyring */
 901        struct key *session_keyring;    /* UID's default session keyring */
 902#endif
 903
 904        /* Hash table maintenance information */
 905        struct hlist_node uidhash_node;
 906        kuid_t uid;
 907
 908#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL)
 909        atomic_long_t locked_vm;
 910#endif
 911};
 912
 913extern int uids_sysfs_init(void);
 914
 915extern struct user_struct *find_user(kuid_t);
 916
 917extern struct user_struct root_user;
 918#define INIT_USER (&root_user)
 919
 920
 921struct backing_dev_info;
 922struct reclaim_state;
 923
 924#ifdef CONFIG_SCHED_INFO
 925struct sched_info {
 926        /* cumulative counters */
 927        unsigned long pcount;         /* # of times run on this cpu */
 928        unsigned long long run_delay; /* time spent waiting on a runqueue */
 929
 930        /* timestamps */
 931        unsigned long long last_arrival,/* when we last ran on a cpu */
 932                           last_queued; /* when we were last queued to run */
 933};
 934#endif /* CONFIG_SCHED_INFO */
 935
 936#ifdef CONFIG_TASK_DELAY_ACCT
 937struct task_delay_info {
 938        spinlock_t      lock;
 939        unsigned int    flags;  /* Private per-task flags */
 940
 941        /* For each stat XXX, add following, aligned appropriately
 942         *
 943         * struct timespec XXX_start, XXX_end;
 944         * u64 XXX_delay;
 945         * u32 XXX_count;
 946         *
 947         * Atomicity of updates to XXX_delay, XXX_count protected by
 948         * single lock above (split into XXX_lock if contention is an issue).
 949         */
 950
 951        /*
 952         * XXX_count is incremented on every XXX operation, the delay
 953         * associated with the operation is added to XXX_delay.
 954         * XXX_delay contains the accumulated delay time in nanoseconds.
 955         */
 956        u64 blkio_start;        /* Shared by blkio, swapin */
 957        u64 blkio_delay;        /* wait for sync block io completion */
 958        u64 swapin_delay;       /* wait for swapin block io completion */
 959        u32 blkio_count;        /* total count of the number of sync block */
 960                                /* io operations performed */
 961        u32 swapin_count;       /* total count of the number of swapin block */
 962                                /* io operations performed */
 963
 964        u64 freepages_start;
 965        u64 freepages_delay;    /* wait for memory reclaim */
 966        u32 freepages_count;    /* total count of memory reclaim */
 967};
 968#endif  /* CONFIG_TASK_DELAY_ACCT */
 969
 970static inline int sched_info_on(void)
 971{
 972#ifdef CONFIG_SCHEDSTATS
 973        return 1;
 974#elif defined(CONFIG_TASK_DELAY_ACCT)
 975        extern int delayacct_on;
 976        return delayacct_on;
 977#else
 978        return 0;
 979#endif
 980}
 981
 982#ifdef CONFIG_SCHEDSTATS
 983void force_schedstat_enabled(void);
 984#endif
 985
 986enum cpu_idle_type {
 987        CPU_IDLE,
 988        CPU_NOT_IDLE,
 989        CPU_NEWLY_IDLE,
 990        CPU_MAX_IDLE_TYPES
 991};
 992
 993/*
 994 * Integer metrics need fixed point arithmetic, e.g., sched/fair
 995 * has a few: load, load_avg, util_avg, freq, and capacity.
 996 *
 997 * We define a basic fixed point arithmetic range, and then formalize
 998 * all these metrics based on that basic range.
 999 */
1000# define SCHED_FIXEDPOINT_SHIFT 10
1001# define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
1002
1003/*
1004 * Increase resolution of cpu_capacity calculations
1005 */
1006#define SCHED_CAPACITY_SHIFT    SCHED_FIXEDPOINT_SHIFT
1007#define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
1008
1009/*
1010 * Wake-queues are lists of tasks with a pending wakeup, whose
1011 * callers have already marked the task as woken internally,
1012 * and can thus carry on. A common use case is being able to
1013 * do the wakeups once the corresponding user lock as been
1014 * released.
1015 *
1016 * We hold reference to each task in the list across the wakeup,
1017 * thus guaranteeing that the memory is still valid by the time
1018 * the actual wakeups are performed in wake_up_q().
1019 *
1020 * One per task suffices, because there's never a need for a task to be
1021 * in two wake queues simultaneously; it is forbidden to abandon a task
1022 * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
1023 * already in a wake queue, the wakeup will happen soon and the second
1024 * waker can just skip it.
1025 *
1026 * The DEFINE_WAKE_Q macro declares and initializes the list head.
1027 * wake_up_q() does NOT reinitialize the list; it's expected to be
1028 * called near the end of a function, where the fact that the queue is
1029 * not used again will be easy to see by inspection.
1030 *
1031 * Note that this can cause spurious wakeups. schedule() callers
1032 * must ensure the call is done inside a loop, confirming that the
1033 * wakeup condition has in fact occurred.
1034 */
1035struct wake_q_node {
1036        struct wake_q_node *next;
1037};
1038
1039struct wake_q_head {
1040        struct wake_q_node *first;
1041        struct wake_q_node **lastp;
1042};
1043
1044#define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
1045
1046#define DEFINE_WAKE_Q(name)                             \
1047        struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
1048
1049extern void wake_q_add(struct wake_q_head *head,
1050                       struct task_struct *task);
1051extern void wake_up_q(struct wake_q_head *head);
1052
1053/*
1054 * sched-domains (multiprocessor balancing) declarations:
1055 */
1056#ifdef CONFIG_SMP
1057#define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
1058#define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
1059#define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
1060#define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
1061#define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
1062#define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
1063#define SD_ASYM_CPUCAPACITY     0x0040  /* Groups have different max cpu capacities */
1064#define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu capacity */
1065#define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
1066#define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
1067#define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
1068#define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
1069#define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
1070#define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
1071#define SD_NUMA                 0x4000  /* cross-node balancing */
1072
1073#ifdef CONFIG_SCHED_SMT
1074static inline int cpu_smt_flags(void)
1075{
1076        return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
1077}
1078#endif
1079
1080#ifdef CONFIG_SCHED_MC
1081static inline int cpu_core_flags(void)
1082{
1083        return SD_SHARE_PKG_RESOURCES;
1084}
1085#endif
1086
1087#ifdef CONFIG_NUMA
1088static inline int cpu_numa_flags(void)
1089{
1090        return SD_NUMA;
1091}
1092#endif
1093
1094extern int arch_asym_cpu_priority(int cpu);
1095
1096struct sched_domain_attr {
1097        int relax_domain_level;
1098};
1099
1100#define SD_ATTR_INIT    (struct sched_domain_attr) {    \
1101        .relax_domain_level = -1,                       \
1102}
1103
1104extern int sched_domain_level_max;
1105
1106struct sched_group;
1107
1108struct sched_domain_shared {
1109        atomic_t        ref;
1110        atomic_t        nr_busy_cpus;
1111        int             has_idle_cores;
1112};
1113
1114struct sched_domain {
1115        /* These fields must be setup */
1116        struct sched_domain *parent;    /* top domain must be null terminated */
1117        struct sched_domain *child;     /* bottom domain must be null terminated */
1118        struct sched_group *groups;     /* the balancing groups of the domain */
1119        unsigned long min_interval;     /* Minimum balance interval ms */
1120        unsigned long max_interval;     /* Maximum balance interval ms */
1121        unsigned int busy_factor;       /* less balancing by factor if busy */
1122        unsigned int imbalance_pct;     /* No balance until over watermark */
1123        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
1124        unsigned int busy_idx;
1125        unsigned int idle_idx;
1126        unsigned int newidle_idx;
1127        unsigned int wake_idx;
1128        unsigned int forkexec_idx;
1129        unsigned int smt_gain;
1130
1131        int nohz_idle;                  /* NOHZ IDLE status */
1132        int flags;                      /* See SD_* */
1133        int level;
1134
1135        /* Runtime fields. */
1136        unsigned long last_balance;     /* init to jiffies. units in jiffies */
1137        unsigned int balance_interval;  /* initialise to 1. units in ms. */
1138        unsigned int nr_balance_failed; /* initialise to 0 */
1139
1140        /* idle_balance() stats */
1141        u64 max_newidle_lb_cost;
1142        unsigned long next_decay_max_lb_cost;
1143
1144        u64 avg_scan_cost;              /* select_idle_sibling */
1145
1146#ifdef CONFIG_SCHEDSTATS
1147        /* load_balance() stats */
1148        unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1149        unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1150        unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1151        unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1152        unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1153        unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1154        unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1155        unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1156
1157        /* Active load balancing */
1158        unsigned int alb_count;
1159        unsigned int alb_failed;
1160        unsigned int alb_pushed;
1161
1162        /* SD_BALANCE_EXEC stats */
1163        unsigned int sbe_count;
1164        unsigned int sbe_balanced;
1165        unsigned int sbe_pushed;
1166
1167        /* SD_BALANCE_FORK stats */
1168        unsigned int sbf_count;
1169        unsigned int sbf_balanced;
1170        unsigned int sbf_pushed;
1171
1172        /* try_to_wake_up() stats */
1173        unsigned int ttwu_wake_remote;
1174        unsigned int ttwu_move_affine;
1175        unsigned int ttwu_move_balance;
1176#endif
1177#ifdef CONFIG_SCHED_DEBUG
1178        char *name;
1179#endif
1180        union {
1181                void *private;          /* used during construction */
1182                struct rcu_head rcu;    /* used during destruction */
1183        };
1184        struct sched_domain_shared *shared;
1185
1186        unsigned int span_weight;
1187        /*
1188         * Span of all CPUs in this domain.
1189         *
1190         * NOTE: this field is variable length. (Allocated dynamically
1191         * by attaching extra space to the end of the structure,
1192         * depending on how many CPUs the kernel has booted up with)
1193         */
1194        unsigned long span[0];
1195};
1196
1197static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1198{
1199        return to_cpumask(sd->span);
1200}
1201
1202extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1203                                    struct sched_domain_attr *dattr_new);
1204
1205/* Allocate an array of sched domains, for partition_sched_domains(). */
1206cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1207void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1208
1209bool cpus_share_cache(int this_cpu, int that_cpu);
1210
1211typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1212typedef int (*sched_domain_flags_f)(void);
1213
1214#define SDTL_OVERLAP    0x01
1215
1216struct sd_data {
1217        struct sched_domain **__percpu sd;
1218        struct sched_domain_shared **__percpu sds;
1219        struct sched_group **__percpu sg;
1220        struct sched_group_capacity **__percpu sgc;
1221};
1222
1223struct sched_domain_topology_level {
1224        sched_domain_mask_f mask;
1225        sched_domain_flags_f sd_flags;
1226        int                 flags;
1227        int                 numa_level;
1228        struct sd_data      data;
1229#ifdef CONFIG_SCHED_DEBUG
1230        char                *name;
1231#endif
1232};
1233
1234extern void set_sched_topology(struct sched_domain_topology_level *tl);
1235extern void wake_up_if_idle(int cpu);
1236
1237#ifdef CONFIG_SCHED_DEBUG
1238# define SD_INIT_NAME(type)             .name = #type
1239#else
1240# define SD_INIT_NAME(type)
1241#endif
1242
1243#else /* CONFIG_SMP */
1244
1245struct sched_domain_attr;
1246
1247static inline void
1248partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1249                        struct sched_domain_attr *dattr_new)
1250{
1251}
1252
1253static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1254{
1255        return true;
1256}
1257
1258#endif  /* !CONFIG_SMP */
1259
1260
1261struct io_context;                      /* See blkdev.h */
1262
1263
1264#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1265extern void prefetch_stack(struct task_struct *t);
1266#else
1267static inline void prefetch_stack(struct task_struct *t) { }
1268#endif
1269
1270struct audit_context;           /* See audit.c */
1271struct mempolicy;
1272struct pipe_inode_info;
1273struct uts_namespace;
1274
1275struct load_weight {
1276        unsigned long weight;
1277        u32 inv_weight;
1278};
1279
1280/*
1281 * The load_avg/util_avg accumulates an infinite geometric series
1282 * (see __update_load_avg() in kernel/sched/fair.c).
1283 *
1284 * [load_avg definition]
1285 *
1286 *   load_avg = runnable% * scale_load_down(load)
1287 *
1288 * where runnable% is the time ratio that a sched_entity is runnable.
1289 * For cfs_rq, it is the aggregated load_avg of all runnable and
1290 * blocked sched_entities.
1291 *
1292 * load_avg may also take frequency scaling into account:
1293 *
1294 *   load_avg = runnable% * scale_load_down(load) * freq%
1295 *
1296 * where freq% is the CPU frequency normalized to the highest frequency.
1297 *
1298 * [util_avg definition]
1299 *
1300 *   util_avg = running% * SCHED_CAPACITY_SCALE
1301 *
1302 * where running% is the time ratio that a sched_entity is running on
1303 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
1304 * and blocked sched_entities.
1305 *
1306 * util_avg may also factor frequency scaling and CPU capacity scaling:
1307 *
1308 *   util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
1309 *
1310 * where freq% is the same as above, and capacity% is the CPU capacity
1311 * normalized to the greatest capacity (due to uarch differences, etc).
1312 *
1313 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
1314 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
1315 * we therefore scale them to as large a range as necessary. This is for
1316 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
1317 *
1318 * [Overflow issue]
1319 *
1320 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
1321 * with the highest load (=88761), always runnable on a single cfs_rq,
1322 * and should not overflow as the number already hits PID_MAX_LIMIT.
1323 *
1324 * For all other cases (including 32-bit kernels), struct load_weight's
1325 * weight will overflow first before we do, because:
1326 *
1327 *    Max(load_avg) <= Max(load.weight)
1328 *
1329 * Then it is the load_weight's responsibility to consider overflow
1330 * issues.
1331 */
1332struct sched_avg {
1333        u64 last_update_time, load_sum;
1334        u32 util_sum, period_contrib;
1335        unsigned long load_avg, util_avg;
1336};
1337
1338#ifdef CONFIG_SCHEDSTATS
1339struct sched_statistics {
1340        u64                     wait_start;
1341        u64                     wait_max;
1342        u64                     wait_count;
1343        u64                     wait_sum;
1344        u64                     iowait_count;
1345        u64                     iowait_sum;
1346
1347        u64                     sleep_start;
1348        u64                     sleep_max;
1349        s64                     sum_sleep_runtime;
1350
1351        u64                     block_start;
1352        u64                     block_max;
1353        u64                     exec_max;
1354        u64                     slice_max;
1355
1356        u64                     nr_migrations_cold;
1357        u64                     nr_failed_migrations_affine;
1358        u64                     nr_failed_migrations_running;
1359        u64                     nr_failed_migrations_hot;
1360        u64                     nr_forced_migrations;
1361
1362        u64                     nr_wakeups;
1363        u64                     nr_wakeups_sync;
1364        u64                     nr_wakeups_migrate;
1365        u64                     nr_wakeups_local;
1366        u64                     nr_wakeups_remote;
1367        u64                     nr_wakeups_affine;
1368        u64                     nr_wakeups_affine_attempts;
1369        u64                     nr_wakeups_passive;
1370        u64                     nr_wakeups_idle;
1371};
1372#endif
1373
1374struct sched_entity {
1375        struct load_weight      load;           /* for load-balancing */
1376        struct rb_node          run_node;
1377        struct list_head        group_node;
1378        unsigned int            on_rq;
1379
1380        u64                     exec_start;
1381        u64                     sum_exec_runtime;
1382        u64                     vruntime;
1383        u64                     prev_sum_exec_runtime;
1384
1385        u64                     nr_migrations;
1386
1387#ifdef CONFIG_SCHEDSTATS
1388        struct sched_statistics statistics;
1389#endif
1390
1391#ifdef CONFIG_FAIR_GROUP_SCHED
1392        int                     depth;
1393        struct sched_entity     *parent;
1394        /* rq on which this entity is (to be) queued: */
1395        struct cfs_rq           *cfs_rq;
1396        /* rq "owned" by this entity/group: */
1397        struct cfs_rq           *my_q;
1398#endif
1399
1400#ifdef CONFIG_SMP
1401        /*
1402         * Per entity load average tracking.
1403         *
1404         * Put into separate cache line so it does not
1405         * collide with read-mostly values above.
1406         */
1407        struct sched_avg        avg ____cacheline_aligned_in_smp;
1408#endif
1409};
1410
1411struct sched_rt_entity {
1412        struct list_head run_list;
1413        unsigned long timeout;
1414        unsigned long watchdog_stamp;
1415        unsigned int time_slice;
1416        unsigned short on_rq;
1417        unsigned short on_list;
1418
1419        struct sched_rt_entity *back;
1420#ifdef CONFIG_RT_GROUP_SCHED
1421        struct sched_rt_entity  *parent;
1422        /* rq on which this entity is (to be) queued: */
1423        struct rt_rq            *rt_rq;
1424        /* rq "owned" by this entity/group: */
1425        struct rt_rq            *my_q;
1426#endif
1427};
1428
1429struct sched_dl_entity {
1430        struct rb_node  rb_node;
1431
1432        /*
1433         * Original scheduling parameters. Copied here from sched_attr
1434         * during sched_setattr(), they will remain the same until
1435         * the next sched_setattr().
1436         */
1437        u64 dl_runtime;         /* maximum runtime for each instance    */
1438        u64 dl_deadline;        /* relative deadline of each instance   */
1439        u64 dl_period;          /* separation of two instances (period) */
1440        u64 dl_bw;              /* dl_runtime / dl_deadline             */
1441
1442        /*
1443         * Actual scheduling parameters. Initialized with the values above,
1444         * they are continously updated during task execution. Note that
1445         * the remaining runtime could be < 0 in case we are in overrun.
1446         */
1447        s64 runtime;            /* remaining runtime for this instance  */
1448        u64 deadline;           /* absolute deadline for this instance  */
1449        unsigned int flags;     /* specifying the scheduler behaviour   */
1450
1451        /*
1452         * Some bool flags:
1453         *
1454         * @dl_throttled tells if we exhausted the runtime. If so, the
1455         * task has to wait for a replenishment to be performed at the
1456         * next firing of dl_timer.
1457         *
1458         * @dl_boosted tells if we are boosted due to DI. If so we are
1459         * outside bandwidth enforcement mechanism (but only until we
1460         * exit the critical section);
1461         *
1462         * @dl_yielded tells if task gave up the cpu before consuming
1463         * all its available runtime during the last job.
1464         */
1465        int dl_throttled, dl_boosted, dl_yielded;
1466
1467        /*
1468         * Bandwidth enforcement timer. Each -deadline task has its
1469         * own bandwidth to be enforced, thus we need one timer per task.
1470         */
1471        struct hrtimer dl_timer;
1472};
1473
1474union rcu_special {
1475        struct {
1476                u8 blocked;
1477                u8 need_qs;
1478                u8 exp_need_qs;
1479                u8 pad; /* Otherwise the compiler can store garbage here. */
1480        } b; /* Bits. */
1481        u32 s; /* Set of bits. */
1482};
1483struct rcu_node;
1484
1485enum perf_event_task_context {
1486        perf_invalid_context = -1,
1487        perf_hw_context = 0,
1488        perf_sw_context,
1489        perf_nr_task_contexts,
1490};
1491
1492/* Track pages that require TLB flushes */
1493struct tlbflush_unmap_batch {
1494        /*
1495         * Each bit set is a CPU that potentially has a TLB entry for one of
1496         * the PFNs being flushed. See set_tlb_ubc_flush_pending().
1497         */
1498        struct cpumask cpumask;
1499
1500        /* True if any bit in cpumask is set */
1501        bool flush_required;
1502
1503        /*
1504         * If true then the PTE was dirty when unmapped. The entry must be
1505         * flushed before IO is initiated or a stale TLB entry potentially
1506         * allows an update without redirtying the page.
1507         */
1508        bool writable;
1509};
1510
1511struct task_struct {
1512#ifdef CONFIG_THREAD_INFO_IN_TASK
1513        /*
1514         * For reasons of header soup (see current_thread_info()), this
1515         * must be the first element of task_struct.
1516         */
1517        struct thread_info thread_info;
1518#endif
1519        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1520        void *stack;
1521        atomic_t usage;
1522        unsigned int flags;     /* per process flags, defined below */
1523        unsigned int ptrace;
1524
1525#ifdef CONFIG_SMP
1526        struct llist_node wake_entry;
1527        int on_cpu;
1528#ifdef CONFIG_THREAD_INFO_IN_TASK
1529        unsigned int cpu;       /* current CPU */
1530#endif
1531        unsigned int wakee_flips;
1532        unsigned long wakee_flip_decay_ts;
1533        struct task_struct *last_wakee;
1534
1535        int wake_cpu;
1536#endif
1537        int on_rq;
1538
1539        int prio, static_prio, normal_prio;
1540        unsigned int rt_priority;
1541        const struct sched_class *sched_class;
1542        struct sched_entity se;
1543        struct sched_rt_entity rt;
1544#ifdef CONFIG_CGROUP_SCHED
1545        struct task_group *sched_task_group;
1546#endif
1547        struct sched_dl_entity dl;
1548
1549#ifdef CONFIG_PREEMPT_NOTIFIERS
1550        /* list of struct preempt_notifier: */
1551        struct hlist_head preempt_notifiers;
1552#endif
1553
1554#ifdef CONFIG_BLK_DEV_IO_TRACE
1555        unsigned int btrace_seq;
1556#endif
1557
1558        unsigned int policy;
1559        int nr_cpus_allowed;
1560        cpumask_t cpus_allowed;
1561
1562#ifdef CONFIG_PREEMPT_RCU
1563        int rcu_read_lock_nesting;
1564        union rcu_special rcu_read_unlock_special;
1565        struct list_head rcu_node_entry;
1566        struct rcu_node *rcu_blocked_node;
1567#endif /* #ifdef CONFIG_PREEMPT_RCU */
1568#ifdef CONFIG_TASKS_RCU
1569        unsigned long rcu_tasks_nvcsw;
1570        bool rcu_tasks_holdout;
1571        struct list_head rcu_tasks_holdout_list;
1572        int rcu_tasks_idle_cpu;
1573#endif /* #ifdef CONFIG_TASKS_RCU */
1574
1575#ifdef CONFIG_SCHED_INFO
1576        struct sched_info sched_info;
1577#endif
1578
1579        struct list_head tasks;
1580#ifdef CONFIG_SMP
1581        struct plist_node pushable_tasks;
1582        struct rb_node pushable_dl_tasks;
1583#endif
1584
1585        struct mm_struct *mm, *active_mm;
1586        /* per-thread vma caching */
1587        u32 vmacache_seqnum;
1588        struct vm_area_struct *vmacache[VMACACHE_SIZE];
1589#if defined(SPLIT_RSS_COUNTING)
1590        struct task_rss_stat    rss_stat;
1591#endif
1592/* task state */
1593        int exit_state;
1594        int exit_code, exit_signal;
1595        int pdeath_signal;  /*  The signal sent when the parent dies  */
1596        unsigned long jobctl;   /* JOBCTL_*, siglock protected */
1597
1598        /* Used for emulating ABI behavior of previous Linux versions */
1599        unsigned int personality;
1600
1601        /* scheduler bits, serialized by scheduler locks */
1602        unsigned sched_reset_on_fork:1;
1603        unsigned sched_contributes_to_load:1;
1604        unsigned sched_migrated:1;
1605        unsigned sched_remote_wakeup:1;
1606        unsigned :0; /* force alignment to the next boundary */
1607
1608        /* unserialized, strictly 'current' */
1609        unsigned in_execve:1; /* bit to tell LSMs we're in execve */
1610        unsigned in_iowait:1;
1611#if !defined(TIF_RESTORE_SIGMASK)
1612        unsigned restore_sigmask:1;
1613#endif
1614#ifdef CONFIG_MEMCG
1615        unsigned memcg_may_oom:1;
1616#ifndef CONFIG_SLOB
1617        unsigned memcg_kmem_skip_account:1;
1618#endif
1619#endif
1620#ifdef CONFIG_COMPAT_BRK
1621        unsigned brk_randomized:1;
1622#endif
1623
1624        unsigned long atomic_flags; /* Flags needing atomic access. */
1625
1626        struct restart_block restart_block;
1627
1628        pid_t pid;
1629        pid_t tgid;
1630
1631#ifdef CONFIG_CC_STACKPROTECTOR
1632        /* Canary value for the -fstack-protector gcc feature */
1633        unsigned long stack_canary;
1634#endif
1635        /*
1636         * pointers to (original) parent process, youngest child, younger sibling,
1637         * older sibling, respectively.  (p->father can be replaced with
1638         * p->real_parent->pid)
1639         */
1640        struct task_struct __rcu *real_parent; /* real parent process */
1641        struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1642        /*
1643         * children/sibling forms the list of my natural children
1644         */
1645        struct list_head children;      /* list of my children */
1646        struct list_head sibling;       /* linkage in my parent's children list */
1647        struct task_struct *group_leader;       /* threadgroup leader */
1648
1649        /*
1650         * ptraced is the list of tasks this task is using ptrace on.
1651         * This includes both natural children and PTRACE_ATTACH targets.
1652         * p->ptrace_entry is p's link on the p->parent->ptraced list.
1653         */
1654        struct list_head ptraced;
1655        struct list_head ptrace_entry;
1656
1657        /* PID/PID hash table linkage. */
1658        struct pid_link pids[PIDTYPE_MAX];
1659        struct list_head thread_group;
1660        struct list_head thread_node;
1661
1662        struct completion *vfork_done;          /* for vfork() */
1663        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1664        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1665
1666        cputime_t utime, stime;
1667#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1668        cputime_t utimescaled, stimescaled;
1669#endif
1670        cputime_t gtime;
1671        struct prev_cputime prev_cputime;
1672#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1673        seqcount_t vtime_seqcount;
1674        unsigned long long vtime_snap;
1675        enum {
1676                /* Task is sleeping or running in a CPU with VTIME inactive */
1677                VTIME_INACTIVE = 0,
1678                /* Task runs in userspace in a CPU with VTIME active */
1679                VTIME_USER,
1680                /* Task runs in kernelspace in a CPU with VTIME active */
1681                VTIME_SYS,
1682        } vtime_snap_whence;
1683#endif
1684
1685#ifdef CONFIG_NO_HZ_FULL
1686        atomic_t tick_dep_mask;
1687#endif
1688        unsigned long nvcsw, nivcsw; /* context switch counts */
1689        u64 start_time;         /* monotonic time in nsec */
1690        u64 real_start_time;    /* boot based time in nsec */
1691/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1692        unsigned long min_flt, maj_flt;
1693
1694        struct task_cputime cputime_expires;
1695        struct list_head cpu_timers[3];
1696
1697/* process credentials */
1698        const struct cred __rcu *ptracer_cred; /* Tracer's credentials at attach */
1699        const struct cred __rcu *real_cred; /* objective and real subjective task
1700                                         * credentials (COW) */
1701        const struct cred __rcu *cred;  /* effective (overridable) subjective task
1702                                         * credentials (COW) */
1703        char comm[TASK_COMM_LEN]; /* executable name excluding path
1704                                     - access with [gs]et_task_comm (which lock
1705                                       it with task_lock())
1706                                     - initialized normally by setup_new_exec */
1707/* file system info */
1708        struct nameidata *nameidata;
1709#ifdef CONFIG_SYSVIPC
1710/* ipc stuff */
1711        struct sysv_sem sysvsem;
1712        struct sysv_shm sysvshm;
1713#endif
1714#ifdef CONFIG_DETECT_HUNG_TASK
1715/* hung task detection */
1716        unsigned long last_switch_count;
1717#endif
1718/* filesystem information */
1719        struct fs_struct *fs;
1720/* open file information */
1721        struct files_struct *files;
1722/* namespaces */
1723        struct nsproxy *nsproxy;
1724/* signal handlers */
1725        struct signal_struct *signal;
1726        struct sighand_struct *sighand;
1727
1728        sigset_t blocked, real_blocked;
1729        sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1730        struct sigpending pending;
1731
1732        unsigned long sas_ss_sp;
1733        size_t sas_ss_size;
1734        unsigned sas_ss_flags;
1735
1736        struct callback_head *task_works;
1737
1738        struct audit_context *audit_context;
1739#ifdef CONFIG_AUDITSYSCALL
1740        kuid_t loginuid;
1741        unsigned int sessionid;
1742#endif
1743        struct seccomp seccomp;
1744
1745/* Thread group tracking */
1746        u32 parent_exec_id;
1747        u32 self_exec_id;
1748/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1749 * mempolicy */
1750        spinlock_t alloc_lock;
1751
1752        /* Protection of the PI data structures: */
1753        raw_spinlock_t pi_lock;
1754
1755        struct wake_q_node wake_q;
1756
1757#ifdef CONFIG_RT_MUTEXES
1758        /* PI waiters blocked on a rt_mutex held by this task */
1759        struct rb_root pi_waiters;
1760        struct rb_node *pi_waiters_leftmost;
1761        /* Deadlock detection and priority inheritance handling */
1762        struct rt_mutex_waiter *pi_blocked_on;
1763#endif
1764
1765#ifdef CONFIG_DEBUG_MUTEXES
1766        /* mutex deadlock detection */
1767        struct mutex_waiter *blocked_on;
1768#endif
1769#ifdef CONFIG_TRACE_IRQFLAGS
1770        unsigned int irq_events;
1771        unsigned long hardirq_enable_ip;
1772        unsigned long hardirq_disable_ip;
1773        unsigned int hardirq_enable_event;
1774        unsigned int hardirq_disable_event;
1775        int hardirqs_enabled;
1776        int hardirq_context;
1777        unsigned long softirq_disable_ip;
1778        unsigned long softirq_enable_ip;
1779        unsigned int softirq_disable_event;
1780        unsigned int softirq_enable_event;
1781        int softirqs_enabled;
1782        int softirq_context;
1783#endif
1784#ifdef CONFIG_LOCKDEP
1785# define MAX_LOCK_DEPTH 48UL
1786        u64 curr_chain_key;
1787        int lockdep_depth;
1788        unsigned int lockdep_recursion;
1789        struct held_lock held_locks[MAX_LOCK_DEPTH];
1790        gfp_t lockdep_reclaim_gfp;
1791#endif
1792#ifdef CONFIG_UBSAN
1793        unsigned int in_ubsan;
1794#endif
1795
1796/* journalling filesystem info */
1797        void *journal_info;
1798
1799/* stacked block device info */
1800        struct bio_list *bio_list;
1801
1802#ifdef CONFIG_BLOCK
1803/* stack plugging */
1804        struct blk_plug *plug;
1805#endif
1806
1807/* VM state */
1808        struct reclaim_state *reclaim_state;
1809
1810        struct backing_dev_info *backing_dev_info;
1811
1812        struct io_context *io_context;
1813
1814        unsigned long ptrace_message;
1815        siginfo_t *last_siginfo; /* For ptrace use.  */
1816        struct task_io_accounting ioac;
1817#if defined(CONFIG_TASK_XACCT)
1818        u64 acct_rss_mem1;      /* accumulated rss usage */
1819        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1820        cputime_t acct_timexpd; /* stime + utime since last update */
1821#endif
1822#ifdef CONFIG_CPUSETS
1823        nodemask_t mems_allowed;        /* Protected by alloc_lock */
1824        seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1825        int cpuset_mem_spread_rotor;
1826        int cpuset_slab_spread_rotor;
1827#endif
1828#ifdef CONFIG_CGROUPS
1829        /* Control Group info protected by css_set_lock */
1830        struct css_set __rcu *cgroups;
1831        /* cg_list protected by css_set_lock and tsk->alloc_lock */
1832        struct list_head cg_list;
1833#endif
1834#ifdef CONFIG_INTEL_RDT_A
1835        int closid;
1836#endif
1837#ifdef CONFIG_FUTEX
1838        struct robust_list_head __user *robust_list;
1839#ifdef CONFIG_COMPAT
1840        struct compat_robust_list_head __user *compat_robust_list;
1841#endif
1842        struct list_head pi_state_list;
1843        struct futex_pi_state *pi_state_cache;
1844#endif
1845#ifdef CONFIG_PERF_EVENTS
1846        struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1847        struct mutex perf_event_mutex;
1848        struct list_head perf_event_list;
1849#endif
1850#ifdef CONFIG_DEBUG_PREEMPT
1851        unsigned long preempt_disable_ip;
1852#endif
1853#ifdef CONFIG_NUMA
1854        struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1855        short il_next;
1856        short pref_node_fork;
1857#endif
1858#ifdef CONFIG_NUMA_BALANCING
1859        int numa_scan_seq;
1860        unsigned int numa_scan_period;
1861        unsigned int numa_scan_period_max;
1862        int numa_preferred_nid;
1863        unsigned long numa_migrate_retry;
1864        u64 node_stamp;                 /* migration stamp  */
1865        u64 last_task_numa_placement;
1866        u64 last_sum_exec_runtime;
1867        struct callback_head numa_work;
1868
1869        struct list_head numa_entry;
1870        struct numa_group *numa_group;
1871
1872        /*
1873         * numa_faults is an array split into four regions:
1874         * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1875         * in this precise order.
1876         *
1877         * faults_memory: Exponential decaying average of faults on a per-node
1878         * basis. Scheduling placement decisions are made based on these
1879         * counts. The values remain static for the duration of a PTE scan.
1880         * faults_cpu: Track the nodes the process was running on when a NUMA
1881         * hinting fault was incurred.
1882         * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1883         * during the current scan window. When the scan completes, the counts
1884         * in faults_memory and faults_cpu decay and these values are copied.
1885         */
1886        unsigned long *numa_faults;
1887        unsigned long total_numa_faults;
1888
1889        /*
1890         * numa_faults_locality tracks if faults recorded during the last
1891         * scan window were remote/local or failed to migrate. The task scan
1892         * period is adapted based on the locality of the faults with different
1893         * weights depending on whether they were shared or private faults
1894         */
1895        unsigned long numa_faults_locality[3];
1896
1897        unsigned long numa_pages_migrated;
1898#endif /* CONFIG_NUMA_BALANCING */
1899
1900#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1901        struct tlbflush_unmap_batch tlb_ubc;
1902#endif
1903
1904        struct rcu_head rcu;
1905
1906        /*
1907         * cache last used pipe for splice
1908         */
1909        struct pipe_inode_info *splice_pipe;
1910
1911        struct page_frag task_frag;
1912
1913#ifdef  CONFIG_TASK_DELAY_ACCT
1914        struct task_delay_info *delays;
1915#endif
1916#ifdef CONFIG_FAULT_INJECTION
1917        int make_it_fail;
1918#endif
1919        /*
1920         * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1921         * balance_dirty_pages() for some dirty throttling pause
1922         */
1923        int nr_dirtied;
1924        int nr_dirtied_pause;
1925        unsigned long dirty_paused_when; /* start of a write-and-pause period */
1926
1927#ifdef CONFIG_LATENCYTOP
1928        int latency_record_count;
1929        struct latency_record latency_record[LT_SAVECOUNT];
1930#endif
1931        /*
1932         * time slack values; these are used to round up poll() and
1933         * select() etc timeout values. These are in nanoseconds.
1934         */
1935        u64 timer_slack_ns;
1936        u64 default_timer_slack_ns;
1937
1938#ifdef CONFIG_KASAN
1939        unsigned int kasan_depth;
1940#endif
1941#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1942        /* Index of current stored address in ret_stack */
1943        int curr_ret_stack;
1944        /* Stack of return addresses for return function tracing */
1945        struct ftrace_ret_stack *ret_stack;
1946        /* time stamp for last schedule */
1947        unsigned long long ftrace_timestamp;
1948        /*
1949         * Number of functions that haven't been traced
1950         * because of depth overrun.
1951         */
1952        atomic_t trace_overrun;
1953        /* Pause for the tracing */
1954        atomic_t tracing_graph_pause;
1955#endif
1956#ifdef CONFIG_TRACING
1957        /* state flags for use by tracers */
1958        unsigned long trace;
1959        /* bitmask and counter of trace recursion */
1960        unsigned long trace_recursion;
1961#endif /* CONFIG_TRACING */
1962#ifdef CONFIG_KCOV
1963        /* Coverage collection mode enabled for this task (0 if disabled). */
1964        enum kcov_mode kcov_mode;
1965        /* Size of the kcov_area. */
1966        unsigned        kcov_size;
1967        /* Buffer for coverage collection. */
1968        void            *kcov_area;
1969        /* kcov desciptor wired with this task or NULL. */
1970        struct kcov     *kcov;
1971#endif
1972#ifdef CONFIG_MEMCG
1973        struct mem_cgroup *memcg_in_oom;
1974        gfp_t memcg_oom_gfp_mask;
1975        int memcg_oom_order;
1976
1977        /* number of pages to reclaim on returning to userland */
1978        unsigned int memcg_nr_pages_over_high;
1979#endif
1980#ifdef CONFIG_UPROBES
1981        struct uprobe_task *utask;
1982#endif
1983#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1984        unsigned int    sequential_io;
1985        unsigned int    sequential_io_avg;
1986#endif
1987#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1988        unsigned long   task_state_change;
1989#endif
1990        int pagefault_disabled;
1991#ifdef CONFIG_MMU
1992        struct task_struct *oom_reaper_list;
1993#endif
1994#ifdef CONFIG_VMAP_STACK
1995        struct vm_struct *stack_vm_area;
1996#endif
1997#ifdef CONFIG_THREAD_INFO_IN_TASK
1998        /* A live task holds one reference. */
1999        atomic_t stack_refcount;
2000#endif
2001/* CPU-specific state of this task */
2002        struct thread_struct thread;
2003/*
2004 * WARNING: on x86, 'thread_struct' contains a variable-sized
2005 * structure.  It *MUST* be at the end of 'task_struct'.
2006 *
2007 * Do not put anything below here!
2008 */
2009};
2010
2011#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
2012extern int arch_task_struct_size __read_mostly;
2013#else
2014# define arch_task_struct_size (sizeof(struct task_struct))
2015#endif
2016
2017#ifdef CONFIG_VMAP_STACK
2018static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
2019{
2020        return t->stack_vm_area;
2021}
2022#else
2023static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
2024{
2025        return NULL;
2026}
2027#endif
2028
2029/* Future-safe accessor for struct task_struct's cpus_allowed. */
2030#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
2031
2032static inline int tsk_nr_cpus_allowed(struct task_struct *p)
2033{
2034        return p->nr_cpus_allowed;
2035}
2036
2037#define TNF_MIGRATED    0x01
2038#define TNF_NO_GROUP    0x02
2039#define TNF_SHARED      0x04
2040#define TNF_FAULT_LOCAL 0x08
2041#define TNF_MIGRATE_FAIL 0x10
2042
2043static inline bool in_vfork(struct task_struct *tsk)
2044{
2045        bool ret;
2046
2047        /*
2048         * need RCU to access ->real_parent if CLONE_VM was used along with
2049         * CLONE_PARENT.
2050         *
2051         * We check real_parent->mm == tsk->mm because CLONE_VFORK does not
2052         * imply CLONE_VM
2053         *
2054         * CLONE_VFORK can be used with CLONE_PARENT/CLONE_THREAD and thus
2055         * ->real_parent is not necessarily the task doing vfork(), so in
2056         * theory we can't rely on task_lock() if we want to dereference it.
2057         *
2058         * And in this case we can't trust the real_parent->mm == tsk->mm
2059         * check, it can be false negative. But we do not care, if init or
2060         * another oom-unkillable task does this it should blame itself.
2061         */
2062        rcu_read_lock();
2063        ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
2064        rcu_read_unlock();
2065
2066        return ret;
2067}
2068
2069#ifdef CONFIG_NUMA_BALANCING
2070extern void task_numa_fault(int last_node, int node, int pages, int flags);
2071extern pid_t task_numa_group_id(struct task_struct *p);
2072extern void set_numabalancing_state(bool enabled);
2073extern void task_numa_free(struct task_struct *p);
2074extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
2075                                        int src_nid, int dst_cpu);
2076#else
2077static inline void task_numa_fault(int last_node, int node, int pages,
2078                                   int flags)
2079{
2080}
2081static inline pid_t task_numa_group_id(struct task_struct *p)
2082{
2083        return 0;
2084}
2085static inline void set_numabalancing_state(bool enabled)
2086{
2087}
2088static inline void task_numa_free(struct task_struct *p)
2089{
2090}
2091static inline bool should_numa_migrate_memory(struct task_struct *p,
2092                                struct page *page, int src_nid, int dst_cpu)
2093{
2094        return true;
2095}
2096#endif
2097
2098static inline struct pid *task_pid(struct task_struct *task)
2099{
2100        return task->pids[PIDTYPE_PID].pid;
2101}
2102
2103static inline struct pid *task_tgid(struct task_struct *task)
2104{
2105        return task->group_leader->pids[PIDTYPE_PID].pid;
2106}
2107
2108/*
2109 * Without tasklist or rcu lock it is not safe to dereference
2110 * the result of task_pgrp/task_session even if task == current,
2111 * we can race with another thread doing sys_setsid/sys_setpgid.
2112 */
2113static inline struct pid *task_pgrp(struct task_struct *task)
2114{
2115        return task->group_leader->pids[PIDTYPE_PGID].pid;
2116}
2117
2118static inline struct pid *task_session(struct task_struct *task)
2119{
2120        return task->group_leader->pids[PIDTYPE_SID].pid;
2121}
2122
2123struct pid_namespace;
2124
2125/*
2126 * the helpers to get the task's different pids as they are seen
2127 * from various namespaces
2128 *
2129 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
2130 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
2131 *                     current.
2132 * task_xid_nr_ns()  : id seen from the ns specified;
2133 *
2134 * set_task_vxid()   : assigns a virtual id to a task;
2135 *
2136 * see also pid_nr() etc in include/linux/pid.h
2137 */
2138pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
2139                        struct pid_namespace *ns);
2140
2141static inline pid_t task_pid_nr(struct task_struct *tsk)
2142{
2143        return tsk->pid;
2144}
2145
2146static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
2147                                        struct pid_namespace *ns)
2148{
2149        return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
2150}
2151
2152static inline pid_t task_pid_vnr(struct task_struct *tsk)
2153{
2154        return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
2155}
2156
2157
2158static inline pid_t task_tgid_nr(struct task_struct *tsk)
2159{
2160        return tsk->tgid;
2161}
2162
2163pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
2164
2165static inline pid_t task_tgid_vnr(struct task_struct *tsk)
2166{
2167        return pid_vnr(task_tgid(tsk));
2168}
2169
2170
2171static inline int pid_alive(const struct task_struct *p);
2172static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
2173{
2174        pid_t pid = 0;
2175
2176        rcu_read_lock();
2177        if (pid_alive(tsk))
2178                pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
2179        rcu_read_unlock();
2180
2181        return pid;
2182}
2183
2184static inline pid_t task_ppid_nr(const struct task_struct *tsk)
2185{
2186        return task_ppid_nr_ns(tsk, &init_pid_ns);
2187}
2188
2189static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
2190                                        struct pid_namespace *ns)
2191{
2192        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
2193}
2194
2195static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
2196{
2197        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
2198}
2199
2200
2201static inline pid_t task_session_nr_ns(struct task_struct *tsk,
2202                                        struct pid_namespace *ns)
2203{
2204        return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
2205}
2206
2207static inline pid_t task_session_vnr(struct task_struct *tsk)
2208{
2209        return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
2210}
2211
2212/* obsolete, do not use */
2213static inline pid_t task_pgrp_nr(struct task_struct *tsk)
2214{
2215        return task_pgrp_nr_ns(tsk, &init_pid_ns);
2216}
2217
2218/**
2219 * pid_alive - check that a task structure is not stale
2220 * @p: Task structure to be checked.
2221 *
2222 * Test if a process is not yet dead (at most zombie state)
2223 * If pid_alive fails, then pointers within the task structure
2224 * can be stale and must not be dereferenced.
2225 *
2226 * Return: 1 if the process is alive. 0 otherwise.
2227 */
2228static inline int pid_alive(const struct task_struct *p)
2229{
2230        return p->pids[PIDTYPE_PID].pid != NULL;
2231}
2232
2233/**
2234 * is_global_init - check if a task structure is init. Since init
2235 * is free to have sub-threads we need to check tgid.
2236 * @tsk: Task structure to be checked.
2237 *
2238 * Check if a task structure is the first user space task the kernel created.
2239 *
2240 * Return: 1 if the task structure is init. 0 otherwise.
2241 */
2242static inline int is_global_init(struct task_struct *tsk)
2243{
2244        return task_tgid_nr(tsk) == 1;
2245}
2246
2247extern struct pid *cad_pid;
2248
2249extern void free_task(struct task_struct *tsk);
2250#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
2251
2252extern void __put_task_struct(struct task_struct *t);
2253
2254static inline void put_task_struct(struct task_struct *t)
2255{
2256        if (atomic_dec_and_test(&t->usage))
2257                __put_task_struct(t);
2258}
2259
2260struct task_struct *task_rcu_dereference(struct task_struct **ptask);
2261struct task_struct *try_get_task_struct(struct task_struct **ptask);
2262
2263#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
2264extern void task_cputime(struct task_struct *t,
2265                         cputime_t *utime, cputime_t *stime);
2266extern cputime_t task_gtime(struct task_struct *t);
2267#else
2268static inline void task_cputime(struct task_struct *t,
2269                                cputime_t *utime, cputime_t *stime)
2270{
2271        *utime = t->utime;
2272        *stime = t->stime;
2273}
2274
2275static inline cputime_t task_gtime(struct task_struct *t)
2276{
2277        return t->gtime;
2278}
2279#endif
2280
2281#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
2282static inline void task_cputime_scaled(struct task_struct *t,
2283                                       cputime_t *utimescaled,
2284                                       cputime_t *stimescaled)
2285{
2286        *utimescaled = t->utimescaled;
2287        *stimescaled = t->stimescaled;
2288}
2289#else
2290static inline void task_cputime_scaled(struct task_struct *t,
2291                                       cputime_t *utimescaled,
2292                                       cputime_t *stimescaled)
2293{
2294        task_cputime(t, utimescaled, stimescaled);
2295}
2296#endif
2297
2298extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2299extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2300
2301/*
2302 * Per process flags
2303 */
2304#define PF_IDLE         0x00000002      /* I am an IDLE thread */
2305#define PF_EXITING      0x00000004      /* getting shut down */
2306#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
2307#define PF_VCPU         0x00000010      /* I'm a virtual CPU */
2308#define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
2309#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
2310#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
2311#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
2312#define PF_DUMPCORE     0x00000200      /* dumped core */
2313#define PF_SIGNALED     0x00000400      /* killed by a signal */
2314#define PF_MEMALLOC     0x00000800      /* Allocating memory */
2315#define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
2316#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
2317#define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
2318#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
2319#define PF_FROZEN       0x00010000      /* frozen for system suspend */
2320#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
2321#define PF_KSWAPD       0x00040000      /* I am kswapd */
2322#define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
2323#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
2324#define PF_KTHREAD      0x00200000      /* I am a kernel thread */
2325#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
2326#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
2327#define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
2328#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
2329#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
2330#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
2331#define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
2332
2333/*
2334 * Only the _current_ task can read/write to tsk->flags, but other
2335 * tasks can access tsk->flags in readonly mode for example
2336 * with tsk_used_math (like during threaded core dumping).
2337 * There is however an exception to this rule during ptrace
2338 * or during fork: the ptracer task is allowed to write to the
2339 * child->flags of its traced child (same goes for fork, the parent
2340 * can write to the child->flags), because we're guaranteed the
2341 * child is not running and in turn not changing child->flags
2342 * at the same time the parent does it.
2343 */
2344#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2345#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2346#define clear_used_math() clear_stopped_child_used_math(current)
2347#define set_used_math() set_stopped_child_used_math(current)
2348#define conditional_stopped_child_used_math(condition, child) \
2349        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2350#define conditional_used_math(condition) \
2351        conditional_stopped_child_used_math(condition, current)
2352#define copy_to_stopped_child_used_math(child) \
2353        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2354/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2355#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2356#define used_math() tsk_used_math(current)
2357
2358/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2359 * __GFP_FS is also cleared as it implies __GFP_IO.
2360 */
2361static inline gfp_t memalloc_noio_flags(gfp_t flags)
2362{
2363        if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2364                flags &= ~(__GFP_IO | __GFP_FS);
2365        return flags;
2366}
2367
2368static inline unsigned int memalloc_noio_save(void)
2369{
2370        unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2371        current->flags |= PF_MEMALLOC_NOIO;
2372        return flags;
2373}
2374
2375static inline void memalloc_noio_restore(unsigned int flags)
2376{
2377        current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2378}
2379
2380/* Per-process atomic flags. */
2381#define PFA_NO_NEW_PRIVS 0      /* May not gain new privileges. */
2382#define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2383#define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2384#define PFA_LMK_WAITING  3      /* Lowmemorykiller is waiting */
2385
2386
2387#define TASK_PFA_TEST(name, func)                                       \
2388        static inline bool task_##func(struct task_struct *p)           \
2389        { return test_bit(PFA_##name, &p->atomic_flags); }
2390#define TASK_PFA_SET(name, func)                                        \
2391        static inline void task_set_##func(struct task_struct *p)       \
2392        { set_bit(PFA_##name, &p->atomic_flags); }
2393#define TASK_PFA_CLEAR(name, func)                                      \
2394        static inline void task_clear_##func(struct task_struct *p)     \
2395        { clear_bit(PFA_##name, &p->atomic_flags); }
2396
2397TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2398TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2399
2400TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2401TASK_PFA_SET(SPREAD_PAGE, spread_page)
2402TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2403
2404TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2405TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2406TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2407
2408TASK_PFA_TEST(LMK_WAITING, lmk_waiting)
2409TASK_PFA_SET(LMK_WAITING, lmk_waiting)
2410
2411/*
2412 * task->jobctl flags
2413 */
2414#define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
2415
2416#define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
2417#define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
2418#define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
2419#define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
2420#define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
2421#define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
2422#define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
2423
2424#define JOBCTL_STOP_DEQUEUED    (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2425#define JOBCTL_STOP_PENDING     (1UL << JOBCTL_STOP_PENDING_BIT)
2426#define JOBCTL_STOP_CONSUME     (1UL << JOBCTL_STOP_CONSUME_BIT)
2427#define JOBCTL_TRAP_STOP        (1UL << JOBCTL_TRAP_STOP_BIT)
2428#define JOBCTL_TRAP_NOTIFY      (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2429#define JOBCTL_TRAPPING         (1UL << JOBCTL_TRAPPING_BIT)
2430#define JOBCTL_LISTENING        (1UL << JOBCTL_LISTENING_BIT)
2431
2432#define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2433#define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2434
2435extern bool task_set_jobctl_pending(struct task_struct *task,
2436                                    unsigned long mask);
2437extern void task_clear_jobctl_trapping(struct task_struct *task);
2438extern void task_clear_jobctl_pending(struct task_struct *task,
2439                                      unsigned long mask);
2440
2441static inline void rcu_copy_process(struct task_struct *p)
2442{
2443#ifdef CONFIG_PREEMPT_RCU
2444        p->rcu_read_lock_nesting = 0;
2445        p->rcu_read_unlock_special.s = 0;
2446        p->rcu_blocked_node = NULL;
2447        INIT_LIST_HEAD(&p->rcu_node_entry);
2448#endif /* #ifdef CONFIG_PREEMPT_RCU */
2449#ifdef CONFIG_TASKS_RCU
2450        p->rcu_tasks_holdout = false;
2451        INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2452        p->rcu_tasks_idle_cpu = -1;
2453#endif /* #ifdef CONFIG_TASKS_RCU */
2454}
2455
2456static inline void tsk_restore_flags(struct task_struct *task,
2457                                unsigned long orig_flags, unsigned long flags)
2458{
2459        task->flags &= ~flags;
2460        task->flags |= orig_flags & flags;
2461}
2462
2463extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2464                                     const struct cpumask *trial);
2465extern int task_can_attach(struct task_struct *p,
2466                           const struct cpumask *cs_cpus_allowed);
2467#ifdef CONFIG_SMP
2468extern void do_set_cpus_allowed(struct task_struct *p,
2469                               const struct cpumask *new_mask);
2470
2471extern int set_cpus_allowed_ptr(struct task_struct *p,
2472                                const struct cpumask *new_mask);
2473#else
2474static inline void do_set_cpus_allowed(struct task_struct *p,
2475                                      const struct cpumask *new_mask)
2476{
2477}
2478static inline int set_cpus_allowed_ptr(struct task_struct *p,
2479                                       const struct cpumask *new_mask)
2480{
2481        if (!cpumask_test_cpu(0, new_mask))
2482                return -EINVAL;
2483        return 0;
2484}
2485#endif
2486
2487#ifdef CONFIG_NO_HZ_COMMON
2488void calc_load_enter_idle(void);
2489void calc_load_exit_idle(void);
2490#else
2491static inline void calc_load_enter_idle(void) { }
2492static inline void calc_load_exit_idle(void) { }
2493#endif /* CONFIG_NO_HZ_COMMON */
2494
2495#ifndef cpu_relax_yield
2496#define cpu_relax_yield() cpu_relax()
2497#endif
2498
2499/*
2500 * Do not use outside of architecture code which knows its limitations.
2501 *
2502 * sched_clock() has no promise of monotonicity or bounded drift between
2503 * CPUs, use (which you should not) requires disabling IRQs.
2504 *
2505 * Please use one of the three interfaces below.
2506 */
2507extern unsigned long long notrace sched_clock(void);
2508/*
2509 * See the comment in kernel/sched/clock.c
2510 */
2511extern u64 running_clock(void);
2512extern u64 sched_clock_cpu(int cpu);
2513
2514
2515extern void sched_clock_init(void);
2516
2517#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2518static inline void sched_clock_tick(void)
2519{
2520}
2521
2522static inline void sched_clock_idle_sleep_event(void)
2523{
2524}
2525
2526static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2527{
2528}
2529
2530static inline u64 cpu_clock(int cpu)
2531{
2532        return sched_clock();
2533}
2534
2535static inline u64 local_clock(void)
2536{
2537        return sched_clock();
2538}
2539#else
2540/*
2541 * Architectures can set this to 1 if they have specified
2542 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2543 * but then during bootup it turns out that sched_clock()
2544 * is reliable after all:
2545 */
2546extern int sched_clock_stable(void);
2547extern void set_sched_clock_stable(void);
2548extern void clear_sched_clock_stable(void);
2549
2550extern void sched_clock_tick(void);
2551extern void sched_clock_idle_sleep_event(void);
2552extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2553
2554/*
2555 * As outlined in clock.c, provides a fast, high resolution, nanosecond
2556 * time source that is monotonic per cpu argument and has bounded drift
2557 * between cpus.
2558 *
2559 * ######################### BIG FAT WARNING ##########################
2560 * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
2561 * # go backwards !!                                                  #
2562 * ####################################################################
2563 */
2564static inline u64 cpu_clock(int cpu)
2565{
2566        return sched_clock_cpu(cpu);
2567}
2568
2569static inline u64 local_clock(void)
2570{
2571        return sched_clock_cpu(raw_smp_processor_id());
2572}
2573#endif
2574
2575#ifdef CONFIG_IRQ_TIME_ACCOUNTING
2576/*
2577 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2578 * The reason for this explicit opt-in is not to have perf penalty with
2579 * slow sched_clocks.
2580 */
2581extern void enable_sched_clock_irqtime(void);
2582extern void disable_sched_clock_irqtime(void);
2583#else
2584static inline void enable_sched_clock_irqtime(void) {}
2585static inline void disable_sched_clock_irqtime(void) {}
2586#endif
2587
2588extern unsigned long long
2589task_sched_runtime(struct task_struct *task);
2590
2591/* sched_exec is called by processes performing an exec */
2592#ifdef CONFIG_SMP
2593extern void sched_exec(void);
2594#else
2595#define sched_exec()   {}
2596#endif
2597
2598extern void sched_clock_idle_sleep_event(void);
2599extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2600
2601#ifdef CONFIG_HOTPLUG_CPU
2602extern void idle_task_exit(void);
2603#else
2604static inline void idle_task_exit(void) {}
2605#endif
2606
2607#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2608extern void wake_up_nohz_cpu(int cpu);
2609#else
2610static inline void wake_up_nohz_cpu(int cpu) { }
2611#endif
2612
2613#ifdef CONFIG_NO_HZ_FULL
2614extern u64 scheduler_tick_max_deferment(void);
2615#endif
2616
2617#ifdef CONFIG_SCHED_AUTOGROUP
2618extern void sched_autogroup_create_attach(struct task_struct *p);
2619extern void sched_autogroup_detach(struct task_struct *p);
2620extern void sched_autogroup_fork(struct signal_struct *sig);
2621extern void sched_autogroup_exit(struct signal_struct *sig);
2622extern void sched_autogroup_exit_task(struct task_struct *p);
2623#ifdef CONFIG_PROC_FS
2624extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2625extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2626#endif
2627#else
2628static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2629static inline void sched_autogroup_detach(struct task_struct *p) { }
2630static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2631static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2632static inline void sched_autogroup_exit_task(struct task_struct *p) { }
2633#endif
2634
2635extern int yield_to(struct task_struct *p, bool preempt);
2636extern void set_user_nice(struct task_struct *p, long nice);
2637extern int task_prio(const struct task_struct *p);
2638/**
2639 * task_nice - return the nice value of a given task.
2640 * @p: the task in question.
2641 *
2642 * Return: The nice value [ -20 ... 0 ... 19 ].
2643 */
2644static inline int task_nice(const struct task_struct *p)
2645{
2646        return PRIO_TO_NICE((p)->static_prio);
2647}
2648extern int can_nice(const struct task_struct *p, const int nice);
2649extern int task_curr(const struct task_struct *p);
2650extern int idle_cpu(int cpu);
2651extern int sched_setscheduler(struct task_struct *, int,
2652                              const struct sched_param *);
2653extern int sched_setscheduler_nocheck(struct task_struct *, int,
2654                                      const struct sched_param *);
2655extern int sched_setattr(struct task_struct *,
2656                         const struct sched_attr *);
2657extern struct task_struct *idle_task(int cpu);
2658/**
2659 * is_idle_task - is the specified task an idle task?
2660 * @p: the task in question.
2661 *
2662 * Return: 1 if @p is an idle task. 0 otherwise.
2663 */
2664static inline bool is_idle_task(const struct task_struct *p)
2665{
2666        return !!(p->flags & PF_IDLE);
2667}
2668extern struct task_struct *curr_task(int cpu);
2669extern void ia64_set_curr_task(int cpu, struct task_struct *p);
2670
2671void yield(void);
2672
2673union thread_union {
2674#ifndef CONFIG_THREAD_INFO_IN_TASK
2675        struct thread_info thread_info;
2676#endif
2677        unsigned long stack[THREAD_SIZE/sizeof(long)];
2678};
2679
2680#ifndef __HAVE_ARCH_KSTACK_END
2681static inline int kstack_end(void *addr)
2682{
2683        /* Reliable end of stack detection:
2684         * Some APM bios versions misalign the stack
2685         */
2686        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2687}
2688#endif
2689
2690extern union thread_union init_thread_union;
2691extern struct task_struct init_task;
2692
2693extern struct   mm_struct init_mm;
2694
2695extern struct pid_namespace init_pid_ns;
2696
2697/*
2698 * find a task by one of its numerical ids
2699 *
2700 * find_task_by_pid_ns():
2701 *      finds a task by its pid in the specified namespace
2702 * find_task_by_vpid():
2703 *      finds a task by its virtual pid
2704 *
2705 * see also find_vpid() etc in include/linux/pid.h
2706 */
2707
2708extern struct task_struct *find_task_by_vpid(pid_t nr);
2709extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2710                struct pid_namespace *ns);
2711
2712/* per-UID process charging. */
2713extern struct user_struct * alloc_uid(kuid_t);
2714static inline struct user_struct *get_uid(struct user_struct *u)
2715{
2716        atomic_inc(&u->__count);
2717        return u;
2718}
2719extern void free_uid(struct user_struct *);
2720
2721#include <asm/current.h>
2722
2723extern void xtime_update(unsigned long ticks);
2724
2725extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2726extern int wake_up_process(struct task_struct *tsk);
2727extern void wake_up_new_task(struct task_struct *tsk);
2728#ifdef CONFIG_SMP
2729 extern void kick_process(struct task_struct *tsk);
2730#else
2731 static inline void kick_process(struct task_struct *tsk) { }
2732#endif
2733extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2734extern void sched_dead(struct task_struct *p);
2735
2736extern void proc_caches_init(void);
2737extern void flush_signals(struct task_struct *);
2738extern void ignore_signals(struct task_struct *);
2739extern void flush_signal_handlers(struct task_struct *, int force_default);
2740extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2741
2742static inline int kernel_dequeue_signal(siginfo_t *info)
2743{
2744        struct task_struct *tsk = current;
2745        siginfo_t __info;
2746        int ret;
2747
2748        spin_lock_irq(&tsk->sighand->siglock);
2749        ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
2750        spin_unlock_irq(&tsk->sighand->siglock);
2751
2752        return ret;
2753}
2754
2755static inline void kernel_signal_stop(void)
2756{
2757        spin_lock_irq(&current->sighand->siglock);
2758        if (current->jobctl & JOBCTL_STOP_DEQUEUED)
2759                __set_current_state(TASK_STOPPED);
2760        spin_unlock_irq(&current->sighand->siglock);
2761
2762        schedule();
2763}
2764
2765extern void release_task(struct task_struct * p);
2766extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2767extern int force_sigsegv(int, struct task_struct *);
2768extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2769extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2770extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2771extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2772                                const struct cred *, u32);
2773extern int kill_pgrp(struct pid *pid, int sig, int priv);
2774extern int kill_pid(struct pid *pid, int sig, int priv);
2775extern int kill_proc_info(int, struct siginfo *, pid_t);
2776extern __must_check bool do_notify_parent(struct task_struct *, int);
2777extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2778extern void force_sig(int, struct task_struct *);
2779extern int send_sig(int, struct task_struct *, int);
2780extern int zap_other_threads(struct task_struct *p);
2781extern struct sigqueue *sigqueue_alloc(void);
2782extern void sigqueue_free(struct sigqueue *);
2783extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2784extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2785
2786#ifdef TIF_RESTORE_SIGMASK
2787/*
2788 * Legacy restore_sigmask accessors.  These are inefficient on
2789 * SMP architectures because they require atomic operations.
2790 */
2791
2792/**
2793 * set_restore_sigmask() - make sure saved_sigmask processing gets done
2794 *
2795 * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
2796 * will run before returning to user mode, to process the flag.  For
2797 * all callers, TIF_SIGPENDING is already set or it's no harm to set
2798 * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
2799 * arch code will notice on return to user mode, in case those bits
2800 * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
2801 * signal code always gets run when TIF_RESTORE_SIGMASK is set.
2802 */
2803static inline void set_restore_sigmask(void)
2804{
2805        set_thread_flag(TIF_RESTORE_SIGMASK);
2806        WARN_ON(!test_thread_flag(TIF_SIGPENDING));
2807}
2808static inline void clear_restore_sigmask(void)
2809{
2810        clear_thread_flag(TIF_RESTORE_SIGMASK);
2811}
2812static inline bool test_restore_sigmask(void)
2813{
2814        return test_thread_flag(TIF_RESTORE_SIGMASK);
2815}
2816static inline bool test_and_clear_restore_sigmask(void)
2817{
2818        return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
2819}
2820
2821#else   /* TIF_RESTORE_SIGMASK */
2822
2823/* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
2824static inline void set_restore_sigmask(void)
2825{
2826        current->restore_sigmask = true;
2827        WARN_ON(!test_thread_flag(TIF_SIGPENDING));
2828}
2829static inline void clear_restore_sigmask(void)
2830{
2831        current->restore_sigmask = false;
2832}
2833static inline bool test_restore_sigmask(void)
2834{
2835        return current->restore_sigmask;
2836}
2837static inline bool test_and_clear_restore_sigmask(void)
2838{
2839        if (!current->restore_sigmask)
2840                return false;
2841        current->restore_sigmask = false;
2842        return true;
2843}
2844#endif
2845
2846static inline void restore_saved_sigmask(void)
2847{
2848        if (test_and_clear_restore_sigmask())
2849                __set_current_blocked(&current->saved_sigmask);
2850}
2851
2852static inline sigset_t *sigmask_to_save(void)
2853{
2854        sigset_t *res = &current->blocked;
2855        if (unlikely(test_restore_sigmask()))
2856                res = &current->saved_sigmask;
2857        return res;
2858}
2859
2860static inline int kill_cad_pid(int sig, int priv)
2861{
2862        return kill_pid(cad_pid, sig, priv);
2863}
2864
2865/* These can be the second arg to send_sig_info/send_group_sig_info.  */
2866#define SEND_SIG_NOINFO ((struct siginfo *) 0)
2867#define SEND_SIG_PRIV   ((struct siginfo *) 1)
2868#define SEND_SIG_FORCED ((struct siginfo *) 2)
2869
2870/*
2871 * True if we are on the alternate signal stack.
2872 */
2873static inline int on_sig_stack(unsigned long sp)
2874{
2875        /*
2876         * If the signal stack is SS_AUTODISARM then, by construction, we
2877         * can't be on the signal stack unless user code deliberately set
2878         * SS_AUTODISARM when we were already on it.
2879         *
2880         * This improves reliability: if user state gets corrupted such that
2881         * the stack pointer points very close to the end of the signal stack,
2882         * then this check will enable the signal to be handled anyway.
2883         */
2884        if (current->sas_ss_flags & SS_AUTODISARM)
2885                return 0;
2886
2887#ifdef CONFIG_STACK_GROWSUP
2888        return sp >= current->sas_ss_sp &&
2889                sp - current->sas_ss_sp < current->sas_ss_size;
2890#else
2891        return sp > current->sas_ss_sp &&
2892                sp - current->sas_ss_sp <= current->sas_ss_size;
2893#endif
2894}
2895
2896static inline int sas_ss_flags(unsigned long sp)
2897{
2898        if (!current->sas_ss_size)
2899                return SS_DISABLE;
2900
2901        return on_sig_stack(sp) ? SS_ONSTACK : 0;
2902}
2903
2904static inline void sas_ss_reset(struct task_struct *p)
2905{
2906        p->sas_ss_sp = 0;
2907        p->sas_ss_size = 0;
2908        p->sas_ss_flags = SS_DISABLE;
2909}
2910
2911static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2912{
2913        if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2914#ifdef CONFIG_STACK_GROWSUP
2915                return current->sas_ss_sp;
2916#else
2917                return current->sas_ss_sp + current->sas_ss_size;
2918#endif
2919        return sp;
2920}
2921
2922/*
2923 * Routines for handling mm_structs
2924 */
2925extern struct mm_struct * mm_alloc(void);
2926
2927/* mmdrop drops the mm and the page tables */
2928extern void __mmdrop(struct mm_struct *);
2929static inline void mmdrop(struct mm_struct *mm)
2930{
2931        if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2932                __mmdrop(mm);
2933}
2934
2935static inline void mmdrop_async_fn(struct work_struct *work)
2936{
2937        struct mm_struct *mm = container_of(work, struct mm_struct, async_put_work);
2938        __mmdrop(mm);
2939}
2940
2941static inline void mmdrop_async(struct mm_struct *mm)
2942{
2943        if (unlikely(atomic_dec_and_test(&mm->mm_count))) {
2944                INIT_WORK(&mm->async_put_work, mmdrop_async_fn);
2945                schedule_work(&mm->async_put_work);
2946        }
2947}
2948
2949static inline bool mmget_not_zero(struct mm_struct *mm)
2950{
2951        return atomic_inc_not_zero(&mm->mm_users);
2952}
2953
2954/* mmput gets rid of the mappings and all user-space */
2955extern void mmput(struct mm_struct *);
2956#ifdef CONFIG_MMU
2957/* same as above but performs the slow path from the async context. Can
2958 * be called from the atomic context as well
2959 */
2960extern void mmput_async(struct mm_struct *);
2961#endif
2962
2963/* Grab a reference to a task's mm, if it is not already going away */
2964extern struct mm_struct *get_task_mm(struct task_struct *task);
2965/*
2966 * Grab a reference to a task's mm, if it is not already going away
2967 * and ptrace_may_access with the mode parameter passed to it
2968 * succeeds.
2969 */
2970extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2971/* Remove the current tasks stale references to the old mm_struct */
2972extern void mm_release(struct task_struct *, struct mm_struct *);
2973
2974#ifdef CONFIG_HAVE_COPY_THREAD_TLS
2975extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2976                        struct task_struct *, unsigned long);
2977#else
2978extern int copy_thread(unsigned long, unsigned long, unsigned long,
2979                        struct task_struct *);
2980
2981/* Architectures that haven't opted into copy_thread_tls get the tls argument
2982 * via pt_regs, so ignore the tls argument passed via C. */
2983static inline int copy_thread_tls(
2984                unsigned long clone_flags, unsigned long sp, unsigned long arg,
2985                struct task_struct *p, unsigned long tls)
2986{
2987        return copy_thread(clone_flags, sp, arg, p);
2988}
2989#endif
2990extern void flush_thread(void);
2991
2992#ifdef CONFIG_HAVE_EXIT_THREAD
2993extern void exit_thread(struct task_struct *tsk);
2994#else
2995static inline void exit_thread(struct task_struct *tsk)
2996{
2997}
2998#endif
2999
3000extern void exit_files(struct task_struct *);
3001extern void __cleanup_sighand(struct sighand_struct *);
3002
3003extern void exit_itimers(struct signal_struct *);
3004extern void flush_itimer_signals(void);
3005
3006extern void do_group_exit(int);
3007
3008extern int do_execve(struct filename *,
3009                     const char __user * const __user *,
3010                     const char __user * const __user *);
3011extern int do_execveat(int, struct filename *,
3012                       const char __user * const __user *,
3013                       const char __user * const __user *,
3014                       int);
3015extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
3016extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
3017struct task_struct *fork_idle(int);
3018extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
3019
3020extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
3021static inline void set_task_comm(struct task_struct *tsk, const char *from)
3022{
3023        __set_task_comm(tsk, from, false);
3024}
3025extern char *get_task_comm(char *to, struct task_struct *tsk);
3026
3027#ifdef CONFIG_SMP
3028void scheduler_ipi(void);
3029extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
3030#else
3031static inline void scheduler_ipi(void) { }
3032static inline unsigned long wait_task_inactive(struct task_struct *p,
3033                                               long match_state)
3034{
3035        return 1;
3036}
3037#endif
3038
3039#define tasklist_empty() \
3040        list_empty(&init_task.tasks)
3041
3042#define next_task(p) \
3043        list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
3044
3045#define for_each_process(p) \
3046        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
3047
3048extern bool current_is_single_threaded(void);
3049
3050/*
3051 * Careful: do_each_thread/while_each_thread is a double loop so
3052 *          'break' will not work as expected - use goto instead.
3053 */
3054#define do_each_thread(g, t) \
3055        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
3056
3057#define while_each_thread(g, t) \
3058        while ((t = next_thread(t)) != g)
3059
3060#define __for_each_thread(signal, t)    \
3061        list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
3062
3063#define for_each_thread(p, t)           \
3064        __for_each_thread((p)->signal, t)
3065
3066/* Careful: this is a double loop, 'break' won't work as expected. */
3067#define for_each_process_thread(p, t)   \
3068        for_each_process(p) for_each_thread(p, t)
3069
3070static inline int get_nr_threads(struct task_struct *tsk)
3071{
3072        return tsk->signal->nr_threads;
3073}
3074
3075static inline bool thread_group_leader(struct task_struct *p)
3076{
3077        return p->exit_signal >= 0;
3078}
3079
3080/* Do to the insanities of de_thread it is possible for a process
3081 * to have the pid of the thread group leader without actually being
3082 * the thread group leader.  For iteration through the pids in proc
3083 * all we care about is that we have a task with the appropriate
3084 * pid, we don't actually care if we have the right task.
3085 */
3086static inline bool has_group_leader_pid(struct task_struct *p)
3087{
3088        return task_pid(p) == p->signal->leader_pid;
3089}
3090
3091static inline
3092bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
3093{
3094        return p1->signal == p2->signal;
3095}
3096
3097static inline struct task_struct *next_thread(const struct task_struct *p)
3098{
3099        return list_entry_rcu(p->thread_group.next,
3100                              struct task_struct, thread_group);
3101}
3102
3103static inline int thread_group_empty(struct task_struct *p)
3104{
3105        return list_empty(&p->thread_group);
3106}
3107
3108#define delay_group_leader(p) \
3109                (thread_group_leader(p) && !thread_group_empty(p))
3110
3111/*
3112 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
3113 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
3114 * pins the final release of task.io_context.  Also protects ->cpuset and
3115 * ->cgroup.subsys[]. And ->vfork_done.
3116 *
3117 * Nests both inside and outside of read_lock(&tasklist_lock).
3118 * It must not be nested with write_lock_irq(&tasklist_lock),
3119 * neither inside nor outside.
3120 */
3121static inline void task_lock(struct task_struct *p)
3122{
3123        spin_lock(&p->alloc_lock);
3124}
3125
3126static inline void task_unlock(struct task_struct *p)
3127{
3128        spin_unlock(&p->alloc_lock);
3129}
3130
3131extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
3132                                                        unsigned long *flags);
3133
3134static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
3135                                                       unsigned long *flags)
3136{
3137        struct sighand_struct *ret;
3138
3139        ret = __lock_task_sighand(tsk, flags);
3140        (void)__cond_lock(&tsk->sighand->siglock, ret);
3141        return ret;
3142}
3143
3144static inline void unlock_task_sighand(struct task_struct *tsk,
3145                                                unsigned long *flags)
3146{
3147        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
3148}
3149
3150/**
3151 * threadgroup_change_begin - mark the beginning of changes to a threadgroup
3152 * @tsk: task causing the changes
3153 *
3154 * All operations which modify a threadgroup - a new thread joining the
3155 * group, death of a member thread (the assertion of PF_EXITING) and
3156 * exec(2) dethreading the process and replacing the leader - are wrapped
3157 * by threadgroup_change_{begin|end}().  This is to provide a place which
3158 * subsystems needing threadgroup stability can hook into for
3159 * synchronization.
3160 */
3161static inline void threadgroup_change_begin(struct task_struct *tsk)
3162{
3163        might_sleep();
3164        cgroup_threadgroup_change_begin(tsk);
3165}
3166
3167/**
3168 * threadgroup_change_end - mark the end of changes to a threadgroup
3169 * @tsk: task causing the changes
3170 *
3171 * See threadgroup_change_begin().
3172 */
3173static inline void threadgroup_change_end(struct task_struct *tsk)
3174{
3175        cgroup_threadgroup_change_end(tsk);
3176}
3177
3178#ifdef CONFIG_THREAD_INFO_IN_TASK
3179
3180static inline struct thread_info *task_thread_info(struct task_struct *task)
3181{
3182        return &task->thread_info;
3183}
3184
3185/*
3186 * When accessing the stack of a non-current task that might exit, use
3187 * try_get_task_stack() instead.  task_stack_page will return a pointer
3188 * that could get freed out from under you.
3189 */
3190static inline void *task_stack_page(const struct task_struct *task)
3191{
3192        return task->stack;
3193}
3194
3195#define setup_thread_stack(new,old)     do { } while(0)
3196
3197static inline unsigned long *end_of_stack(const struct task_struct *task)
3198{
3199        return task->stack;
3200}
3201
3202#elif !defined(__HAVE_THREAD_FUNCTIONS)
3203
3204#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
3205#define task_stack_page(task)   ((void *)(task)->stack)
3206
3207static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
3208{
3209        *task_thread_info(p) = *task_thread_info(org);
3210        task_thread_info(p)->task = p;
3211}
3212
3213/*
3214 * Return the address of the last usable long on the stack.
3215 *
3216 * When the stack grows down, this is just above the thread
3217 * info struct. Going any lower will corrupt the threadinfo.
3218 *
3219 * When the stack grows up, this is the highest address.
3220 * Beyond that position, we corrupt data on the next page.
3221 */
3222static inline unsigned long *end_of_stack(struct task_struct *p)
3223{
3224#ifdef CONFIG_STACK_GROWSUP
3225        return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
3226#else
3227        return (unsigned long *)(task_thread_info(p) + 1);
3228#endif
3229}
3230
3231#endif
3232
3233#ifdef CONFIG_THREAD_INFO_IN_TASK
3234static inline void *try_get_task_stack(struct task_struct *tsk)
3235{
3236        return atomic_inc_not_zero(&tsk->stack_refcount) ?
3237                task_stack_page(tsk) : NULL;
3238}
3239
3240extern void put_task_stack(struct task_struct *tsk);
3241#else
3242static inline void *try_get_task_stack(struct task_struct *tsk)
3243{
3244        return task_stack_page(tsk);
3245}
3246
3247static inline void put_task_stack(struct task_struct *tsk) {}
3248#endif
3249
3250#define task_stack_end_corrupted(task) \
3251                (*(end_of_stack(task)) != STACK_END_MAGIC)
3252
3253static inline int object_is_on_stack(void *obj)
3254{
3255        void *stack = task_stack_page(current);
3256
3257        return (obj >= stack) && (obj < (stack + THREAD_SIZE));
3258}
3259
3260extern void thread_stack_cache_init(void);
3261
3262#ifdef CONFIG_DEBUG_STACK_USAGE
3263static inline unsigned long stack_not_used(struct task_struct *p)
3264{
3265        unsigned long *n = end_of_stack(p);
3266
3267        do {    /* Skip over canary */
3268# ifdef CONFIG_STACK_GROWSUP
3269                n--;
3270# else
3271                n++;
3272# endif
3273        } while (!*n);
3274
3275# ifdef CONFIG_STACK_GROWSUP
3276        return (unsigned long)end_of_stack(p) - (unsigned long)n;
3277# else
3278        return (unsigned long)n - (unsigned long)end_of_stack(p);
3279# endif
3280}
3281#endif
3282extern void set_task_stack_end_magic(struct task_struct *tsk);
3283
3284/* set thread flags in other task's structures
3285 * - see asm/thread_info.h for TIF_xxxx flags available
3286 */
3287static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
3288{
3289        set_ti_thread_flag(task_thread_info(tsk), flag);
3290}
3291
3292static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3293{
3294        clear_ti_thread_flag(task_thread_info(tsk), flag);
3295}
3296
3297static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
3298{
3299        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
3300}
3301
3302static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3303{
3304        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
3305}
3306
3307static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
3308{
3309        return test_ti_thread_flag(task_thread_info(tsk), flag);
3310}
3311
3312static inline void set_tsk_need_resched(struct task_struct *tsk)
3313{
3314        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3315}
3316
3317static inline void clear_tsk_need_resched(struct task_struct *tsk)
3318{
3319        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3320}
3321
3322static inline int test_tsk_need_resched(struct task_struct *tsk)
3323{
3324        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
3325}
3326
3327static inline int restart_syscall(void)
3328{
3329        set_tsk_thread_flag(current, TIF_SIGPENDING);
3330        return -ERESTARTNOINTR;
3331}
3332
3333static inline int signal_pending(struct task_struct *p)
3334{
3335        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
3336}
3337
3338static inline int __fatal_signal_pending(struct task_struct *p)
3339{
3340        return unlikely(sigismember(&p->pending.signal, SIGKILL));
3341}
3342
3343static inline int fatal_signal_pending(struct task_struct *p)
3344{
3345        return signal_pending(p) && __fatal_signal_pending(p);
3346}
3347
3348static inline int signal_pending_state(long state, struct task_struct *p)
3349{
3350        if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
3351                return 0;
3352        if (!signal_pending(p))
3353                return 0;
3354
3355        return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
3356}
3357
3358/*
3359 * cond_resched() and cond_resched_lock(): latency reduction via
3360 * explicit rescheduling in places that are safe. The return
3361 * value indicates whether a reschedule was done in fact.
3362 * cond_resched_lock() will drop the spinlock before scheduling,
3363 * cond_resched_softirq() will enable bhs before scheduling.
3364 */
3365#ifndef CONFIG_PREEMPT
3366extern int _cond_resched(void);
3367#else
3368static inline int _cond_resched(void) { return 0; }
3369#endif
3370
3371#define cond_resched() ({                       \
3372        ___might_sleep(__FILE__, __LINE__, 0);  \
3373        _cond_resched();                        \
3374})
3375
3376extern int __cond_resched_lock(spinlock_t *lock);
3377
3378#define cond_resched_lock(lock) ({                              \
3379        ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
3380        __cond_resched_lock(lock);                              \
3381})
3382
3383extern int __cond_resched_softirq(void);
3384
3385#define cond_resched_softirq() ({                                       \
3386        ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
3387        __cond_resched_softirq();                                       \
3388})
3389
3390static inline void cond_resched_rcu(void)
3391{
3392#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
3393        rcu_read_unlock();
3394        cond_resched();
3395        rcu_read_lock();
3396#endif
3397}
3398
3399static inline unsigned long get_preempt_disable_ip(struct task_struct *p)
3400{
3401#ifdef CONFIG_DEBUG_PREEMPT
3402        return p->preempt_disable_ip;
3403#else
3404        return 0;
3405#endif
3406}
3407
3408/*
3409 * Does a critical section need to be broken due to another
3410 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
3411 * but a general need for low latency)
3412 */
3413static inline int spin_needbreak(spinlock_t *lock)
3414{
3415#ifdef CONFIG_PREEMPT
3416        return spin_is_contended(lock);
3417#else
3418        return 0;
3419#endif
3420}
3421
3422/*
3423 * Idle thread specific functions to determine the need_resched
3424 * polling state.
3425 */
3426#ifdef TIF_POLLING_NRFLAG
3427static inline int tsk_is_polling(struct task_struct *p)
3428{
3429        return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
3430}
3431
3432static inline void __current_set_polling(void)
3433{
3434        set_thread_flag(TIF_POLLING_NRFLAG);
3435}
3436
3437static inline bool __must_check current_set_polling_and_test(void)
3438{
3439        __current_set_polling();
3440
3441        /*
3442         * Polling state must be visible before we test NEED_RESCHED,
3443         * paired by resched_curr()
3444         */
3445        smp_mb__after_atomic();
3446
3447        return unlikely(tif_need_resched());
3448}
3449
3450static inline void __current_clr_polling(void)
3451{
3452        clear_thread_flag(TIF_POLLING_NRFLAG);
3453}
3454
3455static inline bool __must_check current_clr_polling_and_test(void)
3456{
3457        __current_clr_polling();
3458
3459        /*
3460         * Polling state must be visible before we test NEED_RESCHED,
3461         * paired by resched_curr()
3462         */
3463        smp_mb__after_atomic();
3464
3465        return unlikely(tif_need_resched());
3466}
3467
3468#else
3469static inline int tsk_is_polling(struct task_struct *p) { return 0; }
3470static inline void __current_set_polling(void) { }
3471static inline void __current_clr_polling(void) { }
3472
3473static inline bool __must_check current_set_polling_and_test(void)
3474{
3475        return unlikely(tif_need_resched());
3476}
3477static inline bool __must_check current_clr_polling_and_test(void)
3478{
3479        return unlikely(tif_need_resched());
3480}
3481#endif
3482
3483static inline void current_clr_polling(void)
3484{
3485        __current_clr_polling();
3486
3487        /*
3488         * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3489         * Once the bit is cleared, we'll get IPIs with every new
3490         * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3491         * fold.
3492         */
3493        smp_mb(); /* paired with resched_curr() */
3494
3495        preempt_fold_need_resched();
3496}
3497
3498static __always_inline bool need_resched(void)
3499{
3500        return unlikely(tif_need_resched());
3501}
3502
3503/*
3504 * Thread group CPU time accounting.
3505 */
3506void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3507void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3508
3509/*
3510 * Reevaluate whether the task has signals pending delivery.
3511 * Wake the task if so.
3512 * This is required every time the blocked sigset_t changes.
3513 * callers must hold sighand->siglock.
3514 */
3515extern void recalc_sigpending_and_wake(struct task_struct *t);
3516extern void recalc_sigpending(void);
3517
3518extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3519
3520static inline void signal_wake_up(struct task_struct *t, bool resume)
3521{
3522        signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3523}
3524static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3525{
3526        signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3527}
3528
3529/*
3530 * Wrappers for p->thread_info->cpu access. No-op on UP.
3531 */
3532#ifdef CONFIG_SMP
3533
3534static inline unsigned int task_cpu(const struct task_struct *p)
3535{
3536#ifdef CONFIG_THREAD_INFO_IN_TASK
3537        return p->cpu;
3538#else
3539        return task_thread_info(p)->cpu;
3540#endif
3541}
3542
3543static inline int task_node(const struct task_struct *p)
3544{
3545        return cpu_to_node(task_cpu(p));
3546}
3547
3548extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3549
3550#else
3551
3552static inline unsigned int task_cpu(const struct task_struct *p)
3553{
3554        return 0;
3555}
3556
3557static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3558{
3559}
3560
3561#endif /* CONFIG_SMP */
3562
3563/*
3564 * In order to reduce various lock holder preemption latencies provide an
3565 * interface to see if a vCPU is currently running or not.
3566 *
3567 * This allows us to terminate optimistic spin loops and block, analogous to
3568 * the native optimistic spin heuristic of testing if the lock owner task is
3569 * running or not.
3570 */
3571#ifndef vcpu_is_preempted
3572# define vcpu_is_preempted(cpu) false
3573#endif
3574
3575extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3576extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3577
3578#ifdef CONFIG_CGROUP_SCHED
3579extern struct task_group root_task_group;
3580#endif /* CONFIG_CGROUP_SCHED */
3581
3582extern int task_can_switch_user(struct user_struct *up,
3583                                        struct task_struct *tsk);
3584
3585#ifdef CONFIG_TASK_XACCT
3586static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3587{
3588        tsk->ioac.rchar += amt;
3589}
3590
3591static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3592{
3593        tsk->ioac.wchar += amt;
3594}
3595
3596static inline void inc_syscr(struct task_struct *tsk)
3597{
3598        tsk->ioac.syscr++;
3599}
3600
3601static inline void inc_syscw(struct task_struct *tsk)
3602{
3603        tsk->ioac.syscw++;
3604}
3605#else
3606static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3607{
3608}
3609
3610static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3611{
3612}
3613
3614static inline void inc_syscr(struct task_struct *tsk)
3615{
3616}
3617
3618static inline void inc_syscw(struct task_struct *tsk)
3619{
3620}
3621#endif
3622
3623#ifndef TASK_SIZE_OF
3624#define TASK_SIZE_OF(tsk)       TASK_SIZE
3625#endif
3626
3627#ifdef CONFIG_MEMCG
3628extern void mm_update_next_owner(struct mm_struct *mm);
3629#else
3630static inline void mm_update_next_owner(struct mm_struct *mm)
3631{
3632}
3633#endif /* CONFIG_MEMCG */
3634
3635static inline unsigned long task_rlimit(const struct task_struct *tsk,
3636                unsigned int limit)
3637{
3638        return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3639}
3640
3641static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3642                unsigned int limit)
3643{
3644        return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3645}
3646
3647static inline unsigned long rlimit(unsigned int limit)
3648{
3649        return task_rlimit(current, limit);
3650}
3651
3652static inline unsigned long rlimit_max(unsigned int limit)
3653{
3654        return task_rlimit_max(current, limit);
3655}
3656
3657#define SCHED_CPUFREQ_RT        (1U << 0)
3658#define SCHED_CPUFREQ_DL        (1U << 1)
3659#define SCHED_CPUFREQ_IOWAIT    (1U << 2)
3660
3661#define SCHED_CPUFREQ_RT_DL     (SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL)
3662
3663#ifdef CONFIG_CPU_FREQ
3664struct update_util_data {
3665       void (*func)(struct update_util_data *data, u64 time, unsigned int flags);
3666};
3667
3668void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
3669                       void (*func)(struct update_util_data *data, u64 time,
3670                                    unsigned int flags));
3671void cpufreq_remove_update_util_hook(int cpu);
3672#endif /* CONFIG_CPU_FREQ */
3673
3674#endif
3675
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