sched.h

Go to the documentation of this file.

#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>

#include "cpupri.h"

extern __read_mostly int scheduler_running;

/*
 * Convert user-nice values [ -20 ... 0 ... 19 ]
 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
 * and back.
 */
#define NICE_TO_PRIO(nice)  (MAX_RT_PRIO + (nice) + 20)
#define PRIO_TO_NICE(prio)  ((prio) - MAX_RT_PRIO - 20)
#define TASK_NICE(p)        PRIO_TO_NICE((p)->static_prio)

/*
 * 'User priority' is the nice value converted to something we
 * can work with better when scaling various scheduler parameters,
 * it's a [ 0 ... 39 ] range.
 */
#define USER_PRIO(p)        ((p)-MAX_RT_PRIO)
#define TASK_USER_PRIO(p)   USER_PRIO((p)->static_prio)
#define MAX_USER_PRIO       (USER_PRIO(MAX_PRIO))

/*
 * Helpers for converting nanosecond timing to jiffy resolution
 */
#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))

#define NICE_0_LOAD     SCHED_LOAD_SCALE
#define NICE_0_SHIFT        SCHED_LOAD_SHIFT

/*
 * These are the 'tuning knobs' of the scheduler:
 */

/*
 * single value that denotes runtime == period, ie unlimited time.
 */
#define RUNTIME_INF ((u64)~0ULL)

static inline int rt_policy(int policy)
{
    if (policy == SCHED_FIFO || policy == SCHED_RR)
        return 1;
    return 0;
}

static inline int task_has_rt_policy(struct task_struct *p)
{
    return rt_policy(p->policy);
}

/*
 * This is the priority-queue data structure of the RT scheduling class:
 */
struct rt_prio_array {
    DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
    struct list_head queue[MAX_RT_PRIO];
};

struct rt_bandwidth {
    /* nests inside the rq lock: */
    raw_spinlock_t      rt_runtime_lock;
    ktime_t         rt_period;
    u64         rt_runtime;
    struct hrtimer      rt_period_timer;
};

extern struct mutex sched_domains_mutex;

#ifdef CONFIG_CGROUP_SCHED

#include <linux/cgroup.h>

struct cfs_rq;
struct rt_rq;

extern struct list_head task_groups;

struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
    raw_spinlock_t lock;
    ktime_t period;
    u64 quota, runtime;
    s64 hierarchal_quota;
    u64 runtime_expires;

    int idle, timer_active;
    struct hrtimer period_timer, slack_timer;
    struct list_head throttled_cfs_rq;

    /* statistics */
    int nr_periods, nr_throttled;
    u64 throttled_time;
#endif
};

/* task group related information */
struct task_group {
    struct cgroup_subsys_state css;

#ifdef CONFIG_FAIR_GROUP_SCHED
    /* schedulable entities of this group on each cpu */
    struct sched_entity **se;
    /* runqueue "owned" by this group on each cpu */
    struct cfs_rq **cfs_rq;
    unsigned long shares;

    atomic_t load_weight;
#endif

#ifdef CONFIG_RT_GROUP_SCHED
    struct sched_rt_entity **rt_se;
    struct rt_rq **rt_rq;

    struct rt_bandwidth rt_bandwidth;
#endif

    struct rcu_head rcu;
    struct list_head list;

    struct task_group *parent;
    struct list_head siblings;
    struct list_head children;

#ifdef CONFIG_SCHED_AUTOGROUP
    struct autogroup *autogroup;
#endif

    struct cfs_bandwidth cfs_bandwidth;
};

#ifdef CONFIG_FAIR_GROUP_SCHED
#define ROOT_TASK_GROUP_LOAD    NICE_0_LOAD

/*
 * A weight of 0 or 1 can cause arithmetics problems.
 * A weight of a cfs_rq is the sum of weights of which entities
 * are queued on this cfs_rq, so a weight of a entity should not be
 * too large, so as the shares value of a task group.
 * (The default weight is 1024 - so there's no practical
 *  limitation from this.)
 */
#define MIN_SHARES  (1UL <<  1)
#define MAX_SHARES  (1UL << 18)
#endif

/* Default task group.
 *  Every task in system belong to this group at bootup.
 */
extern struct task_group root_task_group;

typedef int (*tg_visitor)(struct task_group *, void *);

extern int walk_tg_tree_from(struct task_group *from,
                 tg_visitor down, tg_visitor up, void *data);

/*
 * Iterate the full tree, calling @down when first entering a node and @up when
 * leaving it for the final time.
 *
 * Caller must hold rcu_lock or sufficient equivalent.
 */
static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
{
    return walk_tg_tree_from(&root_task_group, down, up, data);
}

extern int tg_nop(struct task_group *tg, void *data);

extern void free_fair_sched_group(struct task_group *tg);
extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
            struct sched_entity *se, int cpu,
            struct sched_entity *parent);
extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);

extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);

extern void free_rt_sched_group(struct task_group *tg);
extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
        struct sched_rt_entity *rt_se, int cpu,
        struct sched_rt_entity *parent);

#else /* CONFIG_CGROUP_SCHED */

struct cfs_bandwidth { };

#endif  /* CONFIG_CGROUP_SCHED */

/* CFS-related fields in a runqueue */
struct cfs_rq {
    struct load_weight load;
    unsigned int nr_running, h_nr_running;

    u64 exec_clock;
    u64 min_vruntime;
#ifndef CONFIG_64BIT
    u64 min_vruntime_copy;
#endif

    struct rb_root tasks_timeline;
    struct rb_node *rb_leftmost;

    /*
     * 'curr' points to currently running entity on this cfs_rq.
     * It is set to NULL otherwise (i.e when none are currently running).
     */
    struct sched_entity *curr, *next, *last, *skip;

#ifdef  CONFIG_SCHED_DEBUG
    unsigned int nr_spread_over;
#endif

#ifdef CONFIG_FAIR_GROUP_SCHED
    struct rq *rq;  /* cpu runqueue to which this cfs_rq is attached */

    /*
     * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
     * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
     * (like users, containers etc.)
     *
     * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
     * list is used during load balance.
     */
    int on_list;
    struct list_head leaf_cfs_rq_list;
    struct task_group *tg;  /* group that "owns" this runqueue */

#ifdef CONFIG_SMP
    /*
     *   h_load = weight * f(tg)
     *
     * Where f(tg) is the recursive weight fraction assigned to
     * this group.
     */
    unsigned long h_load;

    /*
     * Maintaining per-cpu shares distribution for group scheduling
     *
     * load_stamp is the last time we updated the load average
     * load_last is the last time we updated the load average and saw load
     * load_unacc_exec_time is currently unaccounted execution time
     */
    u64 load_avg;
    u64 load_period;
    u64 load_stamp, load_last, load_unacc_exec_time;

    unsigned long load_contribution;
#endif /* CONFIG_SMP */
#ifdef CONFIG_CFS_BANDWIDTH
    int runtime_enabled;
    u64 runtime_expires;
    s64 runtime_remaining;

    u64 throttled_timestamp;
    int throttled, throttle_count;
    struct list_head throttled_list;
#endif /* CONFIG_CFS_BANDWIDTH */
#endif /* CONFIG_FAIR_GROUP_SCHED */
};

static inline int rt_bandwidth_enabled(void)
{
    return sysctl_sched_rt_runtime >= 0;
}

/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
    struct rt_prio_array active;
    unsigned int rt_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
    struct {
        int curr; /* highest queued rt task prio */
#ifdef CONFIG_SMP
        int next; /* next highest */
#endif
    } highest_prio;
#endif
#ifdef CONFIG_SMP
    unsigned long rt_nr_migratory;
    unsigned long rt_nr_total;
    int overloaded;
    struct plist_head pushable_tasks;
#endif
    int rt_throttled;
    u64 rt_time;
    u64 rt_runtime;
    /* Nests inside the rq lock: */
    raw_spinlock_t rt_runtime_lock;

#ifdef CONFIG_RT_GROUP_SCHED
    unsigned long rt_nr_boosted;

    struct rq *rq;
    struct list_head leaf_rt_rq_list;
    struct task_group *tg;
#endif
};

#ifdef CONFIG_SMP

/*
 * We add the notion of a root-domain which will be used to define per-domain
 * variables. Each exclusive cpuset essentially defines an island domain by
 * fully partitioning the member cpus from any other cpuset. Whenever a new
 * exclusive cpuset is created, we also create and attach a new root-domain
 * object.
 *
 */
struct root_domain {
    atomic_t refcount;
    atomic_t rto_count;
    struct rcu_head rcu;
    cpumask_var_t span;
    cpumask_var_t online;

    /*
     * The "RT overload" flag: it gets set if a CPU has more than
     * one runnable RT task.
     */
    cpumask_var_t rto_mask;
    struct cpupri cpupri;
};

extern struct root_domain def_root_domain;

#endif /* CONFIG_SMP */

/*
 * This is the main, per-CPU runqueue data structure.
 *
 * Locking rule: those places that want to lock multiple runqueues
 * (such as the load balancing or the thread migration code), lock
 * acquire operations must be ordered by ascending &runqueue.
 */
struct rq {
    /* runqueue lock: */
    raw_spinlock_t lock;

    /*
     * nr_running and cpu_load should be in the same cacheline because
     * remote CPUs use both these fields when doing load calculation.
     */
    unsigned int nr_running;
    #define CPU_LOAD_IDX_MAX 5
    unsigned long cpu_load[CPU_LOAD_IDX_MAX];
    unsigned long last_load_update_tick;
#ifdef CONFIG_NO_HZ
    u64 nohz_stamp;
    unsigned long nohz_flags;
#endif
    int skip_clock_update;

    /* capture load from *all* tasks on this cpu: */
    struct load_weight load;
    unsigned long nr_load_updates;
    u64 nr_switches;

    struct cfs_rq cfs;
    struct rt_rq rt;

#ifdef CONFIG_FAIR_GROUP_SCHED
    /* list of leaf cfs_rq on this cpu: */
    struct list_head leaf_cfs_rq_list;
#ifdef CONFIG_SMP
    unsigned long h_load_throttle;
#endif /* CONFIG_SMP */
#endif /* CONFIG_FAIR_GROUP_SCHED */

#ifdef CONFIG_RT_GROUP_SCHED
    struct list_head leaf_rt_rq_list;
#endif

    /*
     * This is part of a global counter where only the total sum
     * over all CPUs matters. A task can increase this counter on
     * one CPU and if it got migrated afterwards it may decrease
     * it on another CPU. Always updated under the runqueue lock:
     */
    unsigned long nr_uninterruptible;

    struct task_struct *curr, *idle, *stop;
    unsigned long next_balance;
    struct mm_struct *prev_mm;

    u64 clock;
    u64 clock_task;

    atomic_t nr_iowait;

#ifdef CONFIG_SMP
    struct root_domain *rd;
    struct sched_domain *sd;

    unsigned long cpu_power;

    unsigned char idle_balance;
    /* For active balancing */
    int post_schedule;
    int active_balance;
    int push_cpu;
    struct cpu_stop_work active_balance_work;
    /* cpu of this runqueue: */
    int cpu;
    int online;

    struct list_head cfs_tasks;

    u64 rt_avg;
    u64 age_stamp;
    u64 idle_stamp;
    u64 avg_idle;
#endif

#ifdef CONFIG_IRQ_TIME_ACCOUNTING
    u64 prev_irq_time;
#endif
#ifdef CONFIG_PARAVIRT
    u64 prev_steal_time;
#endif
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
    u64 prev_steal_time_rq;
#endif

    /* calc_load related fields */
    unsigned long calc_load_update;
    long calc_load_active;

#ifdef CONFIG_SCHED_HRTICK
#ifdef CONFIG_SMP
    int hrtick_csd_pending;
    struct call_single_data hrtick_csd;
#endif
    struct hrtimer hrtick_timer;
#endif

#ifdef CONFIG_SCHEDSTATS
    /* latency stats */
    struct sched_info rq_sched_info;
    unsigned long long rq_cpu_time;
    /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */

    /* sys_sched_yield() stats */
    unsigned int yld_count;

    /* schedule() stats */
    unsigned int sched_count;
    unsigned int sched_goidle;

    /* try_to_wake_up() stats */
    unsigned int ttwu_count;
    unsigned int ttwu_local;
#endif

#ifdef CONFIG_SMP
    struct llist_head wake_list;
#endif
};

static inline int cpu_of(struct rq *rq)
{
#ifdef CONFIG_SMP
    return rq->cpu;
#else
    return 0;
#endif
}

DECLARE_PER_CPU(struct rq, runqueues);

#define cpu_rq(cpu)     (&per_cpu(runqueues, (cpu)))
#define this_rq()       (&__get_cpu_var(runqueues))
#define task_rq(p)      cpu_rq(task_cpu(p))
#define cpu_curr(cpu)       (cpu_rq(cpu)->curr)
#define raw_rq()        (&__raw_get_cpu_var(runqueues))

#ifdef CONFIG_SMP

#define rcu_dereference_check_sched_domain(p) \
    rcu_dereference_check((p), \
                  lockdep_is_held(&sched_domains_mutex))

/*
 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
 * See detach_destroy_domains: synchronize_sched for details.
 *
 * The domain tree of any CPU may only be accessed from within
 * preempt-disabled sections.
 */
#define for_each_domain(cpu, __sd) \
    for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
            __sd; __sd = __sd->parent)

#define for_each_lower_domain(sd) for (; sd; sd = sd->child)

static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
{
    struct sched_domain *sd, *hsd = NULL;

    for_each_domain(cpu, sd) {
        if (!(sd->flags & flag))
            break;
        hsd = sd;
    }

    return hsd;
}

DECLARE_PER_CPU(struct sched_domain *, sd_llc);
DECLARE_PER_CPU(int, sd_llc_id);

extern int group_balance_cpu(struct sched_group *sg);

#endif /* CONFIG_SMP */

#include "stats.h"
#include "auto_group.h"

#ifdef CONFIG_CGROUP_SCHED

/*
 * Return the group to which this tasks belongs.
 *
 * We cannot use task_subsys_state() and friends because the cgroup
 * subsystem changes that value before the cgroup_subsys::attach() method
 * is called, therefore we cannot pin it and might observe the wrong value.
 *
 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
 * core changes this before calling sched_move_task().
 *
 * Instead we use a 'copy' which is updated from sched_move_task() while
 * holding both task_struct::pi_lock and rq::lock.
 */
static inline struct task_group *task_group(struct task_struct *p)
{
    return p->sched_task_group;
}

/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
{
#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
    struct task_group *tg = task_group(p);
#endif

#ifdef CONFIG_FAIR_GROUP_SCHED
    p->se.cfs_rq = tg->cfs_rq[cpu];
    p->se.parent = tg->se[cpu];
#endif

#ifdef CONFIG_RT_GROUP_SCHED
    p->rt.rt_rq  = tg->rt_rq[cpu];
    p->rt.parent = tg->rt_se[cpu];
#endif
}

#else /* CONFIG_CGROUP_SCHED */

static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
static inline struct task_group *task_group(struct task_struct *p)
{
    return NULL;
}

#endif /* CONFIG_CGROUP_SCHED */

static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
    set_task_rq(p, cpu);
#ifdef CONFIG_SMP
    /*
     * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
     * successfuly executed on another CPU. We must ensure that updates of
     * per-task data have been completed by this moment.
     */
    smp_wmb();
    task_thread_info(p)->cpu = cpu;
#endif
}

/*
 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
 */
#ifdef CONFIG_SCHED_DEBUG
# include <linux/static_key.h>
# define const_debug __read_mostly
#else
# define const_debug const
#endif

extern const_debug unsigned int sysctl_sched_features;

#define SCHED_FEAT(name, enabled)   \
    __SCHED_FEAT_##name ,

enum {
#include "features.h"
    __SCHED_FEAT_NR,
};

#undef SCHED_FEAT

#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
static __always_inline bool static_branch__true(struct static_key *key)
{
    return static_key_true(key); /* Not out of line branch. */
}

static __always_inline bool static_branch__false(struct static_key *key)
{
    return static_key_false(key); /* Out of line branch. */
}

#define SCHED_FEAT(name, enabled)                   \
static __always_inline bool static_branch_##name(struct static_key *key) \
{                                   \
    return static_branch__##enabled(key);               \
}

#include "features.h"

#undef SCHED_FEAT

extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
#define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
#else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */

static inline u64 global_rt_period(void)
{
    return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
}

static inline u64 global_rt_runtime(void)
{
    if (sysctl_sched_rt_runtime < 0)
        return RUNTIME_INF;

    return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
}



static inline int task_current(struct rq *rq, struct task_struct *p)
{
    return rq->curr == p;
}

static inline int task_running(struct rq *rq, struct task_struct *p)
{
#ifdef CONFIG_SMP
    return p->on_cpu;
#else
    return task_current(rq, p);
#endif
}


#ifndef prepare_arch_switch
# define prepare_arch_switch(next)  do { } while (0)
#endif
#ifndef finish_arch_switch
# define finish_arch_switch(prev)   do { } while (0)
#endif
#ifndef finish_arch_post_lock_switch
# define finish_arch_post_lock_switch() do { } while (0)
#endif

#ifndef __ARCH_WANT_UNLOCKED_CTXSW
static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
{
#ifdef CONFIG_SMP
    /*
     * We can optimise this out completely for !SMP, because the
     * SMP rebalancing from interrupt is the only thing that cares
     * here.
     */
    next->on_cpu = 1;
#endif
}

static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
{
#ifdef CONFIG_SMP
    /*
     * After ->on_cpu is cleared, the task can be moved to a different CPU.
     * We must ensure this doesn't happen until the switch is completely
     * finished.
     */
    smp_wmb();
    prev->on_cpu = 0;
#endif
#ifdef CONFIG_DEBUG_SPINLOCK
    /* this is a valid case when another task releases the spinlock */
    rq->lock.owner = current;
#endif
    /*
     * If we are tracking spinlock dependencies then we have to
     * fix up the runqueue lock - which gets 'carried over' from
     * prev into current:
     */
    spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);

    raw_spin_unlock_irq(&rq->lock);
}

#else /* __ARCH_WANT_UNLOCKED_CTXSW */
static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
{
#ifdef CONFIG_SMP
    /*
     * We can optimise this out completely for !SMP, because the
     * SMP rebalancing from interrupt is the only thing that cares
     * here.
     */
    next->on_cpu = 1;
#endif
    raw_spin_unlock(&rq->lock);
}

static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
{
#ifdef CONFIG_SMP
    /*
     * After ->on_cpu is cleared, the task can be moved to a different CPU.
     * We must ensure this doesn't happen until the switch is completely
     * finished.
     */
    smp_wmb();
    prev->on_cpu = 0;
#endif
    local_irq_enable();
}
#endif /* __ARCH_WANT_UNLOCKED_CTXSW */


static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
    lw->weight += inc;
    lw->inv_weight = 0;
}

static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
{
    lw->weight -= dec;
    lw->inv_weight = 0;
}

static inline void update_load_set(struct load_weight *lw, unsigned long w)
{
    lw->weight = w;
    lw->inv_weight = 0;
}

/*
 * To aid in avoiding the subversion of "niceness" due to uneven distribution
 * of tasks with abnormal "nice" values across CPUs the contribution that
 * each task makes to its run queue's load is weighted according to its
 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
 * scaled version of the new time slice allocation that they receive on time
 * slice expiry etc.
 */

#define WEIGHT_IDLEPRIO                3
#define WMULT_IDLEPRIO         1431655765

/*
 * Nice levels are multiplicative, with a gentle 10% change for every
 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
 * nice 1, it will get ~10% less CPU time than another CPU-bound task
 * that remained on nice 0.
 *
 * The "10% effect" is relative and cumulative: from _any_ nice level,
 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
 * If a task goes up by ~10% and another task goes down by ~10% then
 * the relative distance between them is ~25%.)
 */
static const int prio_to_weight[40] = {
 /* -20 */     88761,     71755,     56483,     46273,     36291,
 /* -15 */     29154,     23254,     18705,     14949,     11916,
 /* -10 */      9548,      7620,      6100,      4904,      3906,
 /*  -5 */      3121,      2501,      1991,      1586,      1277,
 /*   0 */      1024,       820,       655,       526,       423,
 /*   5 */       335,       272,       215,       172,       137,
 /*  10 */       110,        87,        70,        56,        45,
 /*  15 */        36,        29,        23,        18,        15,
};

/*
 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
 *
 * In cases where the weight does not change often, we can use the
 * precalculated inverse to speed up arithmetics by turning divisions
 * into multiplications:
 */
static const u32 prio_to_wmult[40] = {
 /* -20 */     48388,     59856,     76040,     92818,    118348,
 /* -15 */    147320,    184698,    229616,    287308,    360437,
 /* -10 */    449829,    563644,    704093,    875809,   1099582,
 /*  -5 */   1376151,   1717300,   2157191,   2708050,   3363326,
 /*   0 */   4194304,   5237765,   6557202,   8165337,  10153587,
 /*   5 */  12820798,  15790321,  19976592,  24970740,  31350126,
 /*  10 */  39045157,  49367440,  61356676,  76695844,  95443717,
 /*  15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
};

/* Time spent by the tasks of the cpu accounting group executing in ... */
enum cpuacct_stat_index {
    CPUACCT_STAT_USER,  /* ... user mode */
    CPUACCT_STAT_SYSTEM,    /* ... kernel mode */

    CPUACCT_STAT_NSTATS,
};


#define sched_class_highest (&stop_sched_class)
#define for_each_class(class) \
   for (class = sched_class_highest; class; class = class->next)

extern const struct sched_class stop_sched_class;
extern const struct sched_class rt_sched_class;
extern const struct sched_class fair_sched_class;
extern const struct sched_class idle_sched_class;


#ifdef CONFIG_SMP

extern void trigger_load_balance(struct rq *rq, int cpu);
extern void idle_balance(int this_cpu, struct rq *this_rq);

#else   /* CONFIG_SMP */

static inline void idle_balance(int cpu, struct rq *rq)
{
}

#endif

extern void sysrq_sched_debug_show(void);
extern void sched_init_granularity(void);
extern void update_max_interval(void);
extern void update_group_power(struct sched_domain *sd, int cpu);
extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu);
extern void init_sched_rt_class(void);
extern void init_sched_fair_class(void);

extern void resched_task(struct task_struct *p);
extern void resched_cpu(int cpu);

extern struct rt_bandwidth def_rt_bandwidth;
extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);

extern void update_idle_cpu_load(struct rq *this_rq);

#ifdef CONFIG_CGROUP_CPUACCT
#include <linux/cgroup.h>
/* track cpu usage of a group of tasks and its child groups */
struct cpuacct {
    struct cgroup_subsys_state css;
    /* cpuusage holds pointer to a u64-type object on every cpu */
    u64 __percpu *cpuusage;
    struct kernel_cpustat __percpu *cpustat;
};

extern struct cgroup_subsys cpuacct_subsys;
extern struct cpuacct root_cpuacct;

/* return cpu accounting group corresponding to this container */
static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
{
    return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
                struct cpuacct, css);
}

/* return cpu accounting group to which this task belongs */
static inline struct cpuacct *task_ca(struct task_struct *tsk)
{
    return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
                struct cpuacct, css);
}

static inline struct cpuacct *parent_ca(struct cpuacct *ca)
{
    if (!ca || !ca->css.cgroup->parent)
        return NULL;
    return cgroup_ca(ca->css.cgroup->parent);
}

extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
#else
static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
#endif

#ifdef CONFIG_PARAVIRT
static inline u64 steal_ticks(u64 steal)
{
    if (unlikely(steal > NSEC_PER_SEC))
        return div_u64(steal, TICK_NSEC);

    return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
}
#endif

static inline void inc_nr_running(struct rq *rq)
{
    rq->nr_running++;
}

static inline void dec_nr_running(struct rq *rq)
{
    rq->nr_running--;
}

extern void update_rq_clock(struct rq *rq);

extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);

extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);

extern const_debug unsigned int sysctl_sched_time_avg;
extern const_debug unsigned int sysctl_sched_nr_migrate;
extern const_debug unsigned int sysctl_sched_migration_cost;

static inline u64 sched_avg_period(void)
{
    return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
}

#ifdef CONFIG_SCHED_HRTICK

/*
 * Use hrtick when:
 *  - enabled by features
 *  - hrtimer is actually high res
 */
static inline int hrtick_enabled(struct rq *rq)
{
    if (!sched_feat(HRTICK))
        return 0;
    if (!cpu_active(cpu_of(rq)))
        return 0;
    return hrtimer_is_hres_active(&rq->hrtick_timer);
}

void hrtick_start(struct rq *rq, u64 delay);

#else

static inline int hrtick_enabled(struct rq *rq)
{
    return 0;
}

#endif /* CONFIG_SCHED_HRTICK */

#ifdef CONFIG_SMP
extern void sched_avg_update(struct rq *rq);
static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
{
    rq->rt_avg += rt_delta;
    sched_avg_update(rq);
}
#else
static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
static inline void sched_avg_update(struct rq *rq) { }
#endif

extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);

#ifdef CONFIG_SMP
#ifdef CONFIG_PREEMPT

static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);

/*
 * fair double_lock_balance: Safely acquires both rq->locks in a fair
 * way at the expense of forcing extra atomic operations in all
 * invocations.  This assures that the double_lock is acquired using the
 * same underlying policy as the spinlock_t on this architecture, which
 * reduces latency compared to the unfair variant below.  However, it
 * also adds more overhead and therefore may reduce throughput.
 */
static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
    __releases(this_rq->lock)
    __acquires(busiest->lock)
    __acquires(this_rq->lock)
{
    raw_spin_unlock(&this_rq->lock);
    double_rq_lock(this_rq, busiest);

    return 1;
}

#else
/*
 * Unfair double_lock_balance: Optimizes throughput at the expense of
 * latency by eliminating extra atomic operations when the locks are
 * already in proper order on entry.  This favors lower cpu-ids and will
 * grant the double lock to lower cpus over higher ids under contention,
 * regardless of entry order into the function.
 */
static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
    __releases(this_rq->lock)
    __acquires(busiest->lock)
    __acquires(this_rq->lock)
{
    int ret = 0;

    if (unlikely(!raw_spin_trylock(&busiest->lock))) {
        if (busiest < this_rq) {
            raw_spin_unlock(&this_rq->lock);
            raw_spin_lock(&busiest->lock);
            raw_spin_lock_nested(&this_rq->lock,
                          SINGLE_DEPTH_NESTING);
            ret = 1;
        } else
            raw_spin_lock_nested(&busiest->lock,
                          SINGLE_DEPTH_NESTING);
    }
    return ret;
}

#endif /* CONFIG_PREEMPT */

/*
 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
 */
static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
{
    if (unlikely(!irqs_disabled())) {
        /* printk() doesn't work good under rq->lock */
        raw_spin_unlock(&this_rq->lock);
        BUG_ON(1);
    }

    return _double_lock_balance(this_rq, busiest);
}

static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
    __releases(busiest->lock)
{
    raw_spin_unlock(&busiest->lock);
    lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
}

/*
 * double_rq_lock - safely lock two runqueues
 *
 * Note this does not disable interrupts like task_rq_lock,
 * you need to do so manually before calling.
 */
static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
    __acquires(rq1->lock)
    __acquires(rq2->lock)
{
    BUG_ON(!irqs_disabled());
    if (rq1 == rq2) {
        raw_spin_lock(&rq1->lock);
        __acquire(rq2->lock);   /* Fake it out ;) */
    } else {
        if (rq1 < rq2) {
            raw_spin_lock(&rq1->lock);
            raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
        } else {
            raw_spin_lock(&rq2->lock);
            raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
        }
    }
}

/*
 * double_rq_unlock - safely unlock two runqueues
 *
 * Note this does not restore interrupts like task_rq_unlock,
 * you need to do so manually after calling.
 */
static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
    __releases(rq1->lock)
    __releases(rq2->lock)
{
    raw_spin_unlock(&rq1->lock);
    if (rq1 != rq2)
        raw_spin_unlock(&rq2->lock);
    else
        __release(rq2->lock);
}

#else /* CONFIG_SMP */

/*
 * double_rq_lock - safely lock two runqueues
 *
 * Note this does not disable interrupts like task_rq_lock,
 * you need to do so manually before calling.
 */
static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
    __acquires(rq1->lock)
    __acquires(rq2->lock)
{
    BUG_ON(!irqs_disabled());
    BUG_ON(rq1 != rq2);
    raw_spin_lock(&rq1->lock);
    __acquire(rq2->lock);   /* Fake it out ;) */
}

/*
 * double_rq_unlock - safely unlock two runqueues
 *
 * Note this does not restore interrupts like task_rq_unlock,
 * you need to do so manually after calling.
 */
static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
    __releases(rq1->lock)
    __releases(rq2->lock)
{
    BUG_ON(rq1 != rq2);
    raw_spin_unlock(&rq1->lock);
    __release(rq2->lock);
}

#endif

extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
extern void print_cfs_stats(struct seq_file *m, int cpu);
extern void print_rt_stats(struct seq_file *m, int cpu);

extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);

extern void account_cfs_bandwidth_used(int enabled, int was_enabled);

#ifdef CONFIG_NO_HZ
enum rq_nohz_flag_bits {
    NOHZ_TICK_STOPPED,
    NOHZ_BALANCE_KICK,
    NOHZ_IDLE,
};

#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
#endif

#ifdef CONFIG_IRQ_TIME_ACCOUNTING

DECLARE_PER_CPU(u64, cpu_hardirq_time);
DECLARE_PER_CPU(u64, cpu_softirq_time);

#ifndef CONFIG_64BIT
DECLARE_PER_CPU(seqcount_t, irq_time_seq);

static inline void irq_time_write_begin(void)
{
    __this_cpu_inc(irq_time_seq.sequence);
    smp_wmb();
}

static inline void irq_time_write_end(void)
{
    smp_wmb();
    __this_cpu_inc(irq_time_seq.sequence);
}

static inline u64 irq_time_read(int cpu)
{
    u64 irq_time;
    unsigned seq;

    do {
        seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
        irq_time = per_cpu(cpu_softirq_time, cpu) +
               per_cpu(cpu_hardirq_time, cpu);
    } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));

    return irq_time;
}
#else /* CONFIG_64BIT */
static inline void irq_time_write_begin(void)
{
}

static inline void irq_time_write_end(void)
{
}

static inline u64 irq_time_read(int cpu)
{
    return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
}
#endif /* CONFIG_64BIT */
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */