OSCL-LXR linux-6.0.1/​kernel/​sched/​sched.h	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Scheduler internal types and methods:
  */
 #ifndef _KERNEL_SCHED_SCHED_H
 #define _KERNEL_SCHED_SCHED_H
 
 #include <linux/sched/affinity.h>
 #include <linux/sched/autogroup.h>
 #include <linux/sched/cpufreq.h>
 #include <linux/sched/deadline.h>
 #include <linux/sched.h>
 #include <linux/sched/loadavg.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/rseq_api.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/smt.h>
 #include <linux/sched/stat.h>
 #include <linux/sched/sysctl.h>
 #include <linux/sched/task_flags.h>
 #include <linux/sched/task.h>
 #include <linux/sched/topology.h>
 
 #include <linux/atomic.h>
 #include <linux/bitmap.h>
 #include <linux/bug.h>
 #include <linux/capability.h>
 #include <linux/cgroup_api.h>
 #include <linux/cgroup.h>
 #include <linux/context_tracking.h>
 #include <linux/cpufreq.h>
 #include <linux/cpumask_api.h>
 #include <linux/ctype.h>
 #include <linux/file.h>
 #include <linux/fs_api.h>
 #include <linux/hrtimer_api.h>
 #include <linux/interrupt.h>
 #include <linux/irq_work.h>
 #include <linux/jiffies.h>
 #include <linux/kref_api.h>
 #include <linux/kthread.h>
 #include <linux/ktime_api.h>
 #include <linux/lockdep_api.h>
 #include <linux/lockdep.h>
 #include <linux/minmax.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mutex_api.h>
 #include <linux/plist.h>
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/profile.h>
 #include <linux/psi.h>
 #include <linux/rcupdate.h>
 #include <linux/seq_file.h>
 #include <linux/seqlock.h>
 #include <linux/softirq.h>
 #include <linux/spinlock_api.h>
 #include <linux/static_key.h>
 #include <linux/stop_machine.h>
 #include <linux/syscalls_api.h>
 #include <linux/syscalls.h>
 #include <linux/tick.h>
 #include <linux/topology.h>
 #include <linux/types.h>
 #include <linux/u64_stats_sync_api.h>
 #include <linux/uaccess.h>
 #include <linux/wait_api.h>
 #include <linux/wait_bit.h>
 #include <linux/workqueue_api.h>
 
 #include <trace/events/power.h>
 #include <trace/events/sched.h>
 
 #include "../workqueue_internal.h"
 
 #ifdef CONFIG_CGROUP_SCHED
 #include <linux/cgroup.h>
 #include <linux/psi.h>
 #endif
 
 #ifdef CONFIG_SCHED_DEBUG
 # include <linux/static_key.h>
 #endif
 
 #ifdef CONFIG_PARAVIRT
 # include <asm/paravirt.h>
 # include <asm/paravirt_api_clock.h>
 #endif
 
 #include "cpupri.h"
 #include "cpudeadline.h"
 
 #ifdef CONFIG_SCHED_DEBUG
 # define SCHED_WARN_ON(x)      WARN_ONCE(x, #x)
 #else
 # define SCHED_WARN_ON(x)      ({ (void)(x), 0; })
 #endif
 
 struct rq;
 struct cpuidle_state;
 
 /* task_struct::on_rq states: */
 #define TASK_ON_RQ_QUEUED   1
 #define TASK_ON_RQ_MIGRATING    2
 
 extern __read_mostly int scheduler_running;
 
 extern unsigned long calc_load_update;
 extern atomic_long_t calc_load_tasks;
 
 extern unsigned int sysctl_sched_child_runs_first;
 
 extern void calc_global_load_tick(struct rq *this_rq);
 extern long calc_load_fold_active(struct rq *this_rq, long adjust);
 
 extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
 
 extern unsigned int sysctl_sched_rt_period;
 extern int sysctl_sched_rt_runtime;
 extern int sched_rr_timeslice;
 
 /*
  * Helpers for converting nanosecond timing to jiffy resolution
  */
 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
 
 /*
  * Increase resolution of nice-level calculations for 64-bit architectures.
  * The extra resolution improves shares distribution and load balancing of
  * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
  * hierarchies, especially on larger systems. This is not a user-visible change
  * and does not change the user-interface for setting shares/weights.
  *
  * We increase resolution only if we have enough bits to allow this increased
  * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
  * are pretty high and the returns do not justify the increased costs.
  *
  * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to
  * increase coverage and consistency always enable it on 64-bit platforms.
  */
 #ifdef CONFIG_64BIT
 # define NICE_0_LOAD_SHIFT  (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
 # define scale_load(w)      ((w) << SCHED_FIXEDPOINT_SHIFT)
 # define scale_load_down(w) \
 ({ \
     unsigned long __w = (w); \
     if (__w) \
         __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
     __w; \
 })
 #else
 # define NICE_0_LOAD_SHIFT  (SCHED_FIXEDPOINT_SHIFT)
 # define scale_load(w)      (w)
 # define scale_load_down(w) (w)
 #endif
 
 /*
  * Task weight (visible to users) and its load (invisible to users) have
  * independent resolution, but they should be well calibrated. We use
  * scale_load() and scale_load_down(w) to convert between them. The
  * following must be true:
  *
  *  scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD
  *
  */
 #define NICE_0_LOAD     (1L << NICE_0_LOAD_SHIFT)
 
 /*
  * Single value that decides SCHED_DEADLINE internal math precision.
  * 10 -> just above 1us
  * 9  -> just above 0.5us
  */
 #define DL_SCALE        10
 
 /*
  * Single value that denotes runtime == period, ie unlimited time.
  */
 #define RUNTIME_INF     ((u64)~0ULL)
 
 static inline int idle_policy(int policy)
 {
     return policy == SCHED_IDLE;
 }
 static inline int fair_policy(int policy)
 {
     return policy == SCHED_NORMAL || policy == SCHED_BATCH;
 }
 
 static inline int rt_policy(int policy)
 {
     return policy == SCHED_FIFO || policy == SCHED_RR;
 }
 
 static inline int dl_policy(int policy)
 {
     return policy == SCHED_DEADLINE;
 }
 static inline bool valid_policy(int policy)
 {
     return idle_policy(policy) || fair_policy(policy) ||
         rt_policy(policy) || dl_policy(policy);
 }
 
 static inline int task_has_idle_policy(struct task_struct *p)
 {
     return idle_policy(p->policy);
 }
 
 static inline int task_has_rt_policy(struct task_struct *p)
 {
     return rt_policy(p->policy);
 }
 
 static inline int task_has_dl_policy(struct task_struct *p)
 {
     return dl_policy(p->policy);
 }
 
 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
 
 static inline void update_avg(u64 *avg, u64 sample)
 {
     s64 diff = sample - *avg;
     *avg += diff / 8;
 }
 
 /*
  * Shifting a value by an exponent greater *or equal* to the size of said value
  * is UB; cap at size-1.
  */
 #define shr_bound(val, shift)                           \
     (val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1))
 
 /*
  * !! For sched_setattr_nocheck() (kernel) only !!
  *
  * This is actually gross. :(
  *
  * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE
  * tasks, but still be able to sleep. We need this on platforms that cannot
  * atomically change clock frequency. Remove once fast switching will be
  * available on such platforms.
  *
  * SUGOV stands for SchedUtil GOVernor.
  */
 #define SCHED_FLAG_SUGOV    0x10000000
 
 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV)
 
 static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se)
 {
 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
     return unlikely(dl_se->flags & SCHED_FLAG_SUGOV);
 #else
     return false;
 #endif
 }
 
 /*
  * Tells if entity @a should preempt entity @b.
  */
 static inline bool
 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
 {
     return dl_entity_is_special(a) ||
            dl_time_before(a->deadline, b->deadline);
 }
 
 /*
  * 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;
     unsigned int        rt_period_active;
 };
 
 void __dl_clear_params(struct task_struct *p);
 
 struct dl_bandwidth {
     raw_spinlock_t      dl_runtime_lock;
     u64         dl_runtime;
     u64         dl_period;
 };
 
 static inline int dl_bandwidth_enabled(void)
 {
     return sysctl_sched_rt_runtime >= 0;
 }
 
 /*
  * To keep the bandwidth of -deadline tasks under control
  * we need some place where:
  *  - store the maximum -deadline bandwidth of each cpu;
  *  - cache the fraction of bandwidth that is currently allocated in
  *    each root domain;
  *
  * This is all done in the data structure below. It is similar to the
  * one used for RT-throttling (rt_bandwidth), with the main difference
  * that, since here we are only interested in admission control, we
  * do not decrease any runtime while the group "executes", neither we
  * need a timer to replenish it.
  *
  * With respect to SMP, bandwidth is given on a per root domain basis,
  * meaning that:
  *  - bw (< 100%) is the deadline bandwidth of each CPU;
  *  - total_bw is the currently allocated bandwidth in each root domain;
  */
 struct dl_bw {
     raw_spinlock_t      lock;
     u64         bw;
     u64         total_bw;
 };
 
 /*
  * Verify the fitness of task @p to run on @cpu taking into account the
  * CPU original capacity and the runtime/deadline ratio of the task.
  *
  * The function will return true if the CPU original capacity of the
  * @cpu scaled by SCHED_CAPACITY_SCALE >= runtime/deadline ratio of the
  * task and false otherwise.
  */
 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu)
 {
     unsigned long cap = arch_scale_cpu_capacity(cpu);
 
     return cap_scale(p->dl.dl_deadline, cap) >= p->dl.dl_runtime;
 }
 
 extern void init_dl_bw(struct dl_bw *dl_b);
 extern int  sched_dl_global_validate(void);
 extern void sched_dl_do_global(void);
 extern int  sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr);
 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);
 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);
 extern bool __checkparam_dl(const struct sched_attr *attr);
 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);
 extern int  dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
 extern int  dl_cpu_busy(int cpu, struct task_struct *p);
 
 #ifdef CONFIG_CGROUP_SCHED
 
 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;
     u64         runtime;
     u64         burst;
     u64         runtime_snap;
     s64         hierarchical_quota;
 
     u8          idle;
     u8          period_active;
     u8          slack_started;
     struct hrtimer      period_timer;
     struct hrtimer      slack_timer;
     struct list_head    throttled_cfs_rq;
 
     /* Statistics: */
     int         nr_periods;
     int         nr_throttled;
     int         nr_burst;
     u64         throttled_time;
     u64         burst_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;
 
     /* A positive value indicates that this is a SCHED_IDLE group. */
     int         idle;
 
 #ifdef  CONFIG_SMP
     /*
      * load_avg can be heavily contended at clock tick time, so put
      * it in its own cacheline separated from the fields above which
      * will also be accessed at each tick.
      */
     atomic_long_t       load_avg ____cacheline_aligned;
 #endif
 #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_UCLAMP_TASK_GROUP
     /* The two decimal precision [%] value requested from user-space */
     unsigned int        uclamp_pct[UCLAMP_CNT];
     /* Clamp values requested for a task group */
     struct uclamp_se    uclamp_req[UCLAMP_CNT];
     /* Effective clamp values used for a task group */
     struct uclamp_se    uclamp[UCLAMP_CNT];
 #endif
 
 };
 
 #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
 
 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 online_fair_sched_group(struct task_group *tg);
 extern void unregister_fair_sched_group(struct task_group *tg);
 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 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 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);
 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us);
 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us);
 extern long sched_group_rt_runtime(struct task_group *tg);
 extern long sched_group_rt_period(struct task_group *tg);
 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
 
 extern struct task_group *sched_create_group(struct task_group *parent);
 extern void sched_online_group(struct task_group *tg,
                    struct task_group *parent);
 extern void sched_destroy_group(struct task_group *tg);
 extern void sched_release_group(struct task_group *tg);
 
 extern void sched_move_task(struct task_struct *tsk);
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
 
 extern int sched_group_set_idle(struct task_group *tg, long idle);
 
 #ifdef CONFIG_SMP
 extern void set_task_rq_fair(struct sched_entity *se,
                  struct cfs_rq *prev, struct cfs_rq *next);
 #else /* !CONFIG_SMP */
 static inline void set_task_rq_fair(struct sched_entity *se,
                  struct cfs_rq *prev, struct cfs_rq *next) { }
 #endif /* CONFIG_SMP */
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
 #else /* CONFIG_CGROUP_SCHED */
 
 struct cfs_bandwidth { };
 
 #endif  /* CONFIG_CGROUP_SCHED */
 
 extern void unregister_rt_sched_group(struct task_group *tg);
 extern void free_rt_sched_group(struct task_group *tg);
 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
 
 /*
  * u64_u32_load/u64_u32_store
  *
  * Use a copy of a u64 value to protect against data race. This is only
  * applicable for 32-bits architectures.
  */
 #ifdef CONFIG_64BIT
 # define u64_u32_load_copy(var, copy)       var
 # define u64_u32_store_copy(var, copy, val) (var = val)
 #else
 # define u64_u32_load_copy(var, copy)                   \
 ({                                  \
     u64 __val, __val_copy;                      \
     do {                                \
         __val_copy = copy;                  \
         /*                          \
          * paired with u64_u32_store_copy(), ordering access    \
          * to var and copy.                 \
          */                         \
         smp_rmb();                      \
         __val = var;                        \
     } while (__val != __val_copy);                  \
     __val;                              \
 })
 # define u64_u32_store_copy(var, copy, val)             \
 do {                                    \
     typeof(val) __val = (val);                  \
     var = __val;                            \
     /*                              \
      * paired with u64_u32_load_copy(), ordering access to var and  \
      * copy.                            \
      */                             \
     smp_wmb();                          \
     copy = __val;                           \
 } while (0)
 #endif
 # define u64_u32_load(var)      u64_u32_load_copy(var, var##_copy)
 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val)
 
 /* CFS-related fields in a runqueue */
 struct cfs_rq {
     struct load_weight  load;
     unsigned int        nr_running;
     unsigned int        h_nr_running;      /* SCHED_{NORMAL,BATCH,IDLE} */
     unsigned int        idle_nr_running;   /* SCHED_IDLE */
     unsigned int        idle_h_nr_running; /* SCHED_IDLE */
 
     u64         exec_clock;
     u64         min_vruntime;
 #ifdef CONFIG_SCHED_CORE
     unsigned int        forceidle_seq;
     u64         min_vruntime_fi;
 #endif
 
 #ifndef CONFIG_64BIT
     u64         min_vruntime_copy;
 #endif
 
     struct rb_root_cached   tasks_timeline;
 
     /*
      * '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;
     struct sched_entity *next;
     struct sched_entity *last;
     struct sched_entity *skip;
 
 #ifdef  CONFIG_SCHED_DEBUG
     unsigned int        nr_spread_over;
 #endif
 
 #ifdef CONFIG_SMP
     /*
      * CFS load tracking
      */
     struct sched_avg    avg;
 #ifndef CONFIG_64BIT
     u64         last_update_time_copy;
 #endif
     struct {
         raw_spinlock_t  lock ____cacheline_aligned;
         int     nr;
         unsigned long   load_avg;
         unsigned long   util_avg;
         unsigned long   runnable_avg;
     } removed;
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
     unsigned long       tg_load_avg_contrib;
     long            propagate;
     long            prop_runnable_sum;
 
     /*
      *   h_load = weight * f(tg)
      *
      * Where f(tg) is the recursive weight fraction assigned to
      * this group.
      */
     unsigned long       h_load;
     u64         last_h_load_update;
     struct sched_entity *h_load_next;
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 #endif /* CONFIG_SMP */
 
 #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 */
 
     /* Locally cached copy of our task_group's idle value */
     int         idle;
 
 #ifdef CONFIG_CFS_BANDWIDTH
     int         runtime_enabled;
     s64         runtime_remaining;
 
     u64         throttled_pelt_idle;
 #ifndef CONFIG_64BIT
     u64                     throttled_pelt_idle_copy;
 #endif
     u64         throttled_clock;
     u64         throttled_clock_pelt;
     u64         throttled_clock_pelt_time;
     int         throttled;
     int         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;
 }
 
 /* RT IPI pull logic requires IRQ_WORK */
 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP)
 # define HAVE_RT_PUSH_IPI
 #endif
 
 /* Real-Time classes' related field in a runqueue: */
 struct rt_rq {
     struct rt_prio_array    active;
     unsigned int        rt_nr_running;
     unsigned int        rr_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 int        rt_nr_migratory;
     unsigned int        rt_nr_total;
     int         overloaded;
     struct plist_head   pushable_tasks;
 
 #endif /* CONFIG_SMP */
     int         rt_queued;
 
     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 int        rt_nr_boosted;
 
     struct rq       *rq;
     struct task_group   *tg;
 #endif
 };
 
 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq)
 {
     return rt_rq->rt_queued && rt_rq->rt_nr_running;
 }
 
 /* Deadline class' related fields in a runqueue */
 struct dl_rq {
     /* runqueue is an rbtree, ordered by deadline */
     struct rb_root_cached   root;
 
     unsigned int        dl_nr_running;
 
 #ifdef CONFIG_SMP
     /*
      * Deadline values of the currently executing and the
      * earliest ready task on this rq. Caching these facilitates
      * the decision whether or not a ready but not running task
      * should migrate somewhere else.
      */
     struct {
         u64     curr;
         u64     next;
     } earliest_dl;
 
     unsigned int        dl_nr_migratory;
     int         overloaded;
 
     /*
      * Tasks on this rq that can be pushed away. They are kept in
      * an rb-tree, ordered by tasks' deadlines, with caching
      * of the leftmost (earliest deadline) element.
      */
     struct rb_root_cached   pushable_dl_tasks_root;
 #else
     struct dl_bw        dl_bw;
 #endif
     /*
      * "Active utilization" for this runqueue: increased when a
      * task wakes up (becomes TASK_RUNNING) and decreased when a
      * task blocks
      */
     u64         running_bw;
 
     /*
      * Utilization of the tasks "assigned" to this runqueue (including
      * the tasks that are in runqueue and the tasks that executed on this
      * CPU and blocked). Increased when a task moves to this runqueue, and
      * decreased when the task moves away (migrates, changes scheduling
      * policy, or terminates).
      * This is needed to compute the "inactive utilization" for the
      * runqueue (inactive utilization = this_bw - running_bw).
      */
     u64         this_bw;
     u64         extra_bw;
 
     /*
      * Inverse of the fraction of CPU utilization that can be reclaimed
      * by the GRUB algorithm.
      */
     u64         bw_ratio;
 };
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 /* An entity is a task if it doesn't "own" a runqueue */
 #define entity_is_task(se)  (!se->my_q)
 
 static inline void se_update_runnable(struct sched_entity *se)
 {
     if (!entity_is_task(se))
         se->runnable_weight = se->my_q->h_nr_running;
 }
 
 static inline long se_runnable(struct sched_entity *se)
 {
     if (entity_is_task(se))
         return !!se->on_rq;
     else
         return se->runnable_weight;
 }
 
 #else
 #define entity_is_task(se)  1
 
 static inline void se_update_runnable(struct sched_entity *se) {}
 
 static inline long se_runnable(struct sched_entity *se)
 {
     return !!se->on_rq;
 }
 #endif
 
 #ifdef CONFIG_SMP
 /*
  * XXX we want to get rid of these helpers and use the full load resolution.
  */
 static inline long se_weight(struct sched_entity *se)
 {
     return scale_load_down(se->load.weight);
 }
 
 
 static inline bool sched_asym_prefer(int a, int b)
 {
     return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
 }
 
 struct perf_domain {
     struct em_perf_domain *em_pd;
     struct perf_domain *next;
     struct rcu_head rcu;
 };
 
 /* Scheduling group status flags */
 #define SG_OVERLOAD     0x1 /* More than one runnable task on a CPU. */
 #define SG_OVERUTILIZED     0x2 /* One or more CPUs are over-utilized. */
 
 /*
  * 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;
 
     /*
      * Indicate pullable load on at least one CPU, e.g:
      * - More than one runnable task
      * - Running task is misfit
      */
     int         overload;
 
     /* Indicate one or more cpus over-utilized (tipping point) */
     int         overutilized;
 
     /*
      * The bit corresponding to a CPU gets set here if such CPU has more
      * than one runnable -deadline task (as it is below for RT tasks).
      */
     cpumask_var_t       dlo_mask;
     atomic_t        dlo_count;
     struct dl_bw        dl_bw;
     struct cpudl        cpudl;
 
     /*
      * Indicate whether a root_domain's dl_bw has been checked or
      * updated. It's monotonously increasing value.
      *
      * Also, some corner cases, like 'wrap around' is dangerous, but given
      * that u64 is 'big enough'. So that shouldn't be a concern.
      */
     u64 visit_gen;
 
 #ifdef HAVE_RT_PUSH_IPI
     /*
      * For IPI pull requests, loop across the rto_mask.
      */
     struct irq_work     rto_push_work;
     raw_spinlock_t      rto_lock;
     /* These are only updated and read within rto_lock */
     int         rto_loop;
     int         rto_cpu;
     /* These atomics are updated outside of a lock */
     atomic_t        rto_loop_next;
     atomic_t        rto_loop_start;
 #endif
     /*
      * 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;
 
     unsigned long       max_cpu_capacity;
 
     /*
      * NULL-terminated list of performance domains intersecting with the
      * CPUs of the rd. Protected by RCU.
      */
     struct perf_domain __rcu *pd;
 };
 
 extern void init_defrootdomain(void);
 extern int sched_init_domains(const struct cpumask *cpu_map);
 extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
 extern void sched_get_rd(struct root_domain *rd);
 extern void sched_put_rd(struct root_domain *rd);
 
 #ifdef HAVE_RT_PUSH_IPI
 extern void rto_push_irq_work_func(struct irq_work *work);
 #endif
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_UCLAMP_TASK
 /*
  * struct uclamp_bucket - Utilization clamp bucket
  * @value: utilization clamp value for tasks on this clamp bucket
  * @tasks: number of RUNNABLE tasks on this clamp bucket
  *
  * Keep track of how many tasks are RUNNABLE for a given utilization
  * clamp value.
  */
 struct uclamp_bucket {
     unsigned long value : bits_per(SCHED_CAPACITY_SCALE);
     unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE);
 };
 
 /*
  * struct uclamp_rq - rq's utilization clamp
  * @value: currently active clamp values for a rq
  * @bucket: utilization clamp buckets affecting a rq
  *
  * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values.
  * A clamp value is affecting a rq when there is at least one task RUNNABLE
  * (or actually running) with that value.
  *
  * There are up to UCLAMP_CNT possible different clamp values, currently there
  * are only two: minimum utilization and maximum utilization.
  *
  * All utilization clamping values are MAX aggregated, since:
  * - for util_min: we want to run the CPU at least at the max of the minimum
  *   utilization required by its currently RUNNABLE tasks.
  * - for util_max: we want to allow the CPU to run up to the max of the
  *   maximum utilization allowed by its currently RUNNABLE tasks.
  *
  * Since on each system we expect only a limited number of different
  * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track
  * the metrics required to compute all the per-rq utilization clamp values.
  */
 struct uclamp_rq {
     unsigned int value;
     struct uclamp_bucket bucket[UCLAMP_BUCKETS];
 };
 
 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used);
 #endif /* CONFIG_UCLAMP_TASK */
 
 /*
  * 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;
 #ifdef CONFIG_NUMA_BALANCING
     unsigned int        nr_numa_running;
     unsigned int        nr_preferred_running;
     unsigned int        numa_migrate_on;
 #endif
 #ifdef CONFIG_NO_HZ_COMMON
 #ifdef CONFIG_SMP
     unsigned long       last_blocked_load_update_tick;
     unsigned int        has_blocked_load;
     call_single_data_t  nohz_csd;
 #endif /* CONFIG_SMP */
     unsigned int        nohz_tick_stopped;
     atomic_t        nohz_flags;
 #endif /* CONFIG_NO_HZ_COMMON */
 
 #ifdef CONFIG_SMP
     unsigned int        ttwu_pending;
 #endif
     u64         nr_switches;
 
 #ifdef CONFIG_UCLAMP_TASK
     /* Utilization clamp values based on CPU's RUNNABLE tasks */
     struct uclamp_rq    uclamp[UCLAMP_CNT] ____cacheline_aligned;
     unsigned int        uclamp_flags;
 #define UCLAMP_FLAG_IDLE 0x01
 #endif
 
     struct cfs_rq       cfs;
     struct rt_rq        rt;
     struct dl_rq        dl;
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
     /* list of leaf cfs_rq on this CPU: */
     struct list_head    leaf_cfs_rq_list;
     struct list_head    *tmp_alone_branch;
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
     /*
      * 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 int        nr_uninterruptible;
 
     struct task_struct __rcu    *curr;
     struct task_struct  *idle;
     struct task_struct  *stop;
     unsigned long       next_balance;
     struct mm_struct    *prev_mm;
 
     unsigned int        clock_update_flags;
     u64         clock;
     /* Ensure that all clocks are in the same cache line */
     u64         clock_task ____cacheline_aligned;
     u64         clock_pelt;
     unsigned long       lost_idle_time;
     u64         clock_pelt_idle;
     u64         clock_idle;
 #ifndef CONFIG_64BIT
     u64         clock_pelt_idle_copy;
     u64         clock_idle_copy;
 #endif
 
     atomic_t        nr_iowait;
 
 #ifdef CONFIG_SCHED_DEBUG
     u64 last_seen_need_resched_ns;
     int ticks_without_resched;
 #endif
 
 #ifdef CONFIG_MEMBARRIER
     int membarrier_state;
 #endif
 
 #ifdef CONFIG_SMP
     struct root_domain      *rd;
     struct sched_domain __rcu   *sd;
 
     unsigned long       cpu_capacity;
     unsigned long       cpu_capacity_orig;
 
     struct callback_head    *balance_callback;
 
     unsigned char       nohz_idle_balance;
     unsigned char       idle_balance;
 
     unsigned long       misfit_task_load;
 
     /* For active balancing */
     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;
 
     struct sched_avg    avg_rt;
     struct sched_avg    avg_dl;
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
     struct sched_avg    avg_irq;
 #endif
 #ifdef CONFIG_SCHED_THERMAL_PRESSURE
     struct sched_avg    avg_thermal;
 #endif
     u64         idle_stamp;
     u64         avg_idle;
 
     unsigned long       wake_stamp;
     u64         wake_avg_idle;
 
     /* This is used to determine avg_idle's max value */
     u64         max_idle_balance_cost;
 
 #ifdef CONFIG_HOTPLUG_CPU
     struct rcuwait      hotplug_wait;
 #endif
 #endif /* CONFIG_SMP */
 
 #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
     call_single_data_t  hrtick_csd;
 #endif
     struct hrtimer      hrtick_timer;
     ktime_t         hrtick_time;
 #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_CPU_IDLE
     /* Must be inspected within a rcu lock section */
     struct cpuidle_state    *idle_state;
 #endif
 
 #ifdef CONFIG_SMP
     unsigned int        nr_pinned;
 #endif
     unsigned int        push_busy;
     struct cpu_stop_work    push_work;
 
 #ifdef CONFIG_SCHED_CORE
     /* per rq */
     struct rq       *core;
     struct task_struct  *core_pick;
     unsigned int        core_enabled;
     unsigned int        core_sched_seq;
     struct rb_root      core_tree;
 
     /* shared state -- careful with sched_core_cpu_deactivate() */
     unsigned int        core_task_seq;
     unsigned int        core_pick_seq;
     unsigned long       core_cookie;
     unsigned int        core_forceidle_count;
     unsigned int        core_forceidle_seq;
     unsigned int        core_forceidle_occupation;
     u64         core_forceidle_start;
 #endif
 };
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 
 /* CPU runqueue to which this cfs_rq is attached */
 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
 {
     return cfs_rq->rq;
 }
 
 #else
 
 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
 {
     return container_of(cfs_rq, struct rq, cfs);
 }
 #endif
 
 static inline int cpu_of(struct rq *rq)
 {
 #ifdef CONFIG_SMP
     return rq->cpu;
 #else
     return 0;
 #endif
 }
 
 #define MDF_PUSH    0x01
 
 static inline bool is_migration_disabled(struct task_struct *p)
 {
 #ifdef CONFIG_SMP
     return p->migration_disabled;
 #else
     return false;
 #endif
 }
 
 struct sched_group;
 #ifdef CONFIG_SCHED_CORE
 static inline struct cpumask *sched_group_span(struct sched_group *sg);
 
 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled);
 
 static inline bool sched_core_enabled(struct rq *rq)
 {
     return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled;
 }
 
 static inline bool sched_core_disabled(void)
 {
     return !static_branch_unlikely(&__sched_core_enabled);
 }
 
 /*
  * Be careful with this function; not for general use. The return value isn't
  * stable unless you actually hold a relevant rq->__lock.
  */
 static inline raw_spinlock_t *rq_lockp(struct rq *rq)
 {
     if (sched_core_enabled(rq))
         return &rq->core->__lock;
 
     return &rq->__lock;
 }
 
 static inline raw_spinlock_t *__rq_lockp(struct rq *rq)
 {
     if (rq->core_enabled)
         return &rq->core->__lock;
 
     return &rq->__lock;
 }
 
 bool cfs_prio_less(struct task_struct *a, struct task_struct *b, bool fi);
 
 /*
  * Helpers to check if the CPU's core cookie matches with the task's cookie
  * when core scheduling is enabled.
  * A special case is that the task's cookie always matches with CPU's core
  * cookie if the CPU is in an idle core.
  */
 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p)
 {
     /* Ignore cookie match if core scheduler is not enabled on the CPU. */
     if (!sched_core_enabled(rq))
         return true;
 
     return rq->core->core_cookie == p->core_cookie;
 }
 
 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
 {
     bool idle_core = true;
     int cpu;
 
     /* Ignore cookie match if core scheduler is not enabled on the CPU. */
     if (!sched_core_enabled(rq))
         return true;
 
     for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) {
         if (!available_idle_cpu(cpu)) {
             idle_core = false;
             break;
         }
     }
 
     /*
      * A CPU in an idle core is always the best choice for tasks with
      * cookies.
      */
     return idle_core || rq->core->core_cookie == p->core_cookie;
 }
 
 static inline bool sched_group_cookie_match(struct rq *rq,
                         struct task_struct *p,
                         struct sched_group *group)
 {
     int cpu;
 
     /* Ignore cookie match if core scheduler is not enabled on the CPU. */
     if (!sched_core_enabled(rq))
         return true;
 
     for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) {
         if (sched_core_cookie_match(rq, p))
             return true;
     }
     return false;
 }
 
 static inline bool sched_core_enqueued(struct task_struct *p)
 {
     return !RB_EMPTY_NODE(&p->core_node);
 }
 
 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p);
 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags);
 
 extern void sched_core_get(void);
 extern void sched_core_put(void);
 
 #else /* !CONFIG_SCHED_CORE */
 
 static inline bool sched_core_enabled(struct rq *rq)
 {
     return false;
 }
 
 static inline bool sched_core_disabled(void)
 {
     return true;
 }
 
 static inline raw_spinlock_t *rq_lockp(struct rq *rq)
 {
     return &rq->__lock;
 }
 
 static inline raw_spinlock_t *__rq_lockp(struct rq *rq)
 {
     return &rq->__lock;
 }
 
 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p)
 {
     return true;
 }
 
 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
 {
     return true;
 }
 
 static inline bool sched_group_cookie_match(struct rq *rq,
                         struct task_struct *p,
                         struct sched_group *group)
 {
     return true;
 }
 #endif /* CONFIG_SCHED_CORE */
 
 static inline void lockdep_assert_rq_held(struct rq *rq)
 {
     lockdep_assert_held(__rq_lockp(rq));
 }
 
 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass);
 extern bool raw_spin_rq_trylock(struct rq *rq);
 extern void raw_spin_rq_unlock(struct rq *rq);
 
 static inline void raw_spin_rq_lock(struct rq *rq)
 {
     raw_spin_rq_lock_nested(rq, 0);
 }
 
 static inline void raw_spin_rq_lock_irq(struct rq *rq)
 {
     local_irq_disable();
     raw_spin_rq_lock(rq);
 }
 
 static inline void raw_spin_rq_unlock_irq(struct rq *rq)
 {
     raw_spin_rq_unlock(rq);
     local_irq_enable();
 }
 
 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq)
 {
     unsigned long flags;
     local_irq_save(flags);
     raw_spin_rq_lock(rq);
     return flags;
 }
 
 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags)
 {
     raw_spin_rq_unlock(rq);
     local_irq_restore(flags);
 }
 
 #define raw_spin_rq_lock_irqsave(rq, flags) \
 do {                        \
     flags = _raw_spin_rq_lock_irqsave(rq);  \
 } while (0)
 
 #ifdef CONFIG_SCHED_SMT
 extern void __update_idle_core(struct rq *rq);
 
 static inline void update_idle_core(struct rq *rq)
 {
     if (static_branch_unlikely(&sched_smt_present))
         __update_idle_core(rq);
 }
 
 #else
 static inline void update_idle_core(struct rq *rq) { }
 #endif
 
 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
 #define cpu_rq(cpu)     (&per_cpu(runqueues, (cpu)))
 #define this_rq()       this_cpu_ptr(&runqueues)
 #define task_rq(p)      cpu_rq(task_cpu(p))
 #define cpu_curr(cpu)       (cpu_rq(cpu)->curr)
 #define raw_rq()        raw_cpu_ptr(&runqueues)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 static inline struct task_struct *task_of(struct sched_entity *se)
 {
     SCHED_WARN_ON(!entity_is_task(se));
     return container_of(se, struct task_struct, se);
 }
 
 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
 {
     return p->se.cfs_rq;
 }
 
 /* runqueue on which this entity is (to be) queued */
 static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
 {
     return se->cfs_rq;
 }
 
 /* runqueue "owned" by this group */
 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
 {
     return grp->my_q;
 }
 
 #else
 
 static inline struct task_struct *task_of(struct sched_entity *se)
 {
     return container_of(se, struct task_struct, se);
 }
 
 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
 {
     return &task_rq(p)->cfs;
 }
 
 static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
 {
     struct task_struct *p = task_of(se);
     struct rq *rq = task_rq(p);
 
     return &rq->cfs;
 }
 
 /* runqueue "owned" by this group */
 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
 {
     return NULL;
 }
 #endif
 
 extern void update_rq_clock(struct rq *rq);
 
 /*
  * rq::clock_update_flags bits
  *
  * %RQCF_REQ_SKIP - will request skipping of clock update on the next
  *  call to __schedule(). This is an optimisation to avoid
  *  neighbouring rq clock updates.
  *
  * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is
  *  in effect and calls to update_rq_clock() are being ignored.
  *
  * %RQCF_UPDATED - is a debug flag that indicates whether a call has been
  *  made to update_rq_clock() since the last time rq::lock was pinned.
  *
  * If inside of __schedule(), clock_update_flags will have been
  * shifted left (a left shift is a cheap operation for the fast path
  * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use,
  *
  *  if (rq-clock_update_flags >= RQCF_UPDATED)
  *
  * to check if %RQCF_UPDATED is set. It'll never be shifted more than
  * one position though, because the next rq_unpin_lock() will shift it
  * back.
  */
 #define RQCF_REQ_SKIP       0x01
 #define RQCF_ACT_SKIP       0x02
 #define RQCF_UPDATED        0x04
 
 static inline void assert_clock_updated(struct rq *rq)
 {
     /*
      * The only reason for not seeing a clock update since the
      * last rq_pin_lock() is if we're currently skipping updates.
      */
     SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP);
 }
 
 static inline u64 rq_clock(struct rq *rq)
 {
     lockdep_assert_rq_held(rq);
     assert_clock_updated(rq);
 
     return rq->clock;
 }
 
 static inline u64 rq_clock_task(struct rq *rq)
 {
     lockdep_assert_rq_held(rq);
     assert_clock_updated(rq);
 
     return rq->clock_task;
 }
 
 /**
  * By default the decay is the default pelt decay period.
  * The decay shift can change the decay period in
  * multiples of 32.
  *  Decay shift     Decay period(ms)
  *  0           32
  *  1           64
  *  2           128
  *  3           256
  *  4           512
  */
 extern int sched_thermal_decay_shift;
 
 static inline u64 rq_clock_thermal(struct rq *rq)
 {
     return rq_clock_task(rq) >> sched_thermal_decay_shift;
 }
 
 static inline void rq_clock_skip_update(struct rq *rq)
 {
     lockdep_assert_rq_held(rq);
     rq->clock_update_flags |= RQCF_REQ_SKIP;
 }
 
 /*
  * See rt task throttling, which is the only time a skip
  * request is canceled.
  */
 static inline void rq_clock_cancel_skipupdate(struct rq *rq)
 {
     lockdep_assert_rq_held(rq);
     rq->clock_update_flags &= ~RQCF_REQ_SKIP;
 }
 
 struct rq_flags {
     unsigned long flags;
     struct pin_cookie cookie;
 #ifdef CONFIG_SCHED_DEBUG
     /*
      * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
      * current pin context is stashed here in case it needs to be
      * restored in rq_repin_lock().
      */
     unsigned int clock_update_flags;
 #endif
 };
 
 extern struct callback_head balance_push_callback;
 
 /*
  * Lockdep annotation that avoids accidental unlocks; it's like a
  * sticky/continuous lockdep_assert_held().
  *
  * This avoids code that has access to 'struct rq *rq' (basically everything in
  * the scheduler) from accidentally unlocking the rq if they do not also have a
  * copy of the (on-stack) 'struct rq_flags rf'.
  *
  * Also see Documentation/locking/lockdep-design.rst.
  */
 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
 {
     rf->cookie = lockdep_pin_lock(__rq_lockp(rq));
 
 #ifdef CONFIG_SCHED_DEBUG
     rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
     rf->clock_update_flags = 0;
 #ifdef CONFIG_SMP
     SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback);
 #endif
 #endif
 }
 
 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
 {
 #ifdef CONFIG_SCHED_DEBUG
     if (rq->clock_update_flags > RQCF_ACT_SKIP)
         rf->clock_update_flags = RQCF_UPDATED;
 #endif
 
     lockdep_unpin_lock(__rq_lockp(rq), rf->cookie);
 }
 
 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
 {
     lockdep_repin_lock(__rq_lockp(rq), rf->cookie);
 
 #ifdef CONFIG_SCHED_DEBUG
     /*
      * Restore the value we stashed in @rf for this pin context.
      */
     rq->clock_update_flags |= rf->clock_update_flags;
 #endif
 }
 
 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
     __acquires(rq->lock);
 
 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
     __acquires(p->pi_lock)
     __acquires(rq->lock);
 
 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
     __releases(rq->lock)
 {
     rq_unpin_lock(rq, rf);
     raw_spin_rq_unlock(rq);
 }
 
 static inline void
 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
     __releases(rq->lock)
     __releases(p->pi_lock)
 {
     rq_unpin_lock(rq, rf);
     raw_spin_rq_unlock(rq);
     raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
 }
 
 static inline void
 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
     __acquires(rq->lock)
 {
     raw_spin_rq_lock_irqsave(rq, rf->flags);
     rq_pin_lock(rq, rf);
 }
 
 static inline void
 rq_lock_irq(struct rq *rq, struct rq_flags *rf)
     __acquires(rq->lock)
 {
     raw_spin_rq_lock_irq(rq);
     rq_pin_lock(rq, rf);
 }
 
 static inline void
 rq_lock(struct rq *rq, struct rq_flags *rf)
     __acquires(rq->lock)
 {
     raw_spin_rq_lock(rq);
     rq_pin_lock(rq, rf);
 }
 
 static inline void
 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf)
     __releases(rq->lock)
 {
     rq_unpin_lock(rq, rf);
     raw_spin_rq_unlock_irqrestore(rq, rf->flags);
 }
 
 static inline void
 rq_unlock_irq(struct rq *rq, struct rq_flags *rf)
     __releases(rq->lock)
 {
     rq_unpin_lock(rq, rf);
     raw_spin_rq_unlock_irq(rq);
 }
 
 static inline void
 rq_unlock(struct rq *rq, struct rq_flags *rf)
     __releases(rq->lock)
 {
     rq_unpin_lock(rq, rf);
     raw_spin_rq_unlock(rq);
 }
 
 static inline struct rq *
 this_rq_lock_irq(struct rq_flags *rf)
     __acquires(rq->lock)
 {
     struct rq *rq;
 
     local_irq_disable();
     rq = this_rq();
     rq_lock(rq, rf);
     return rq;
 }
 
 #ifdef CONFIG_NUMA
 enum numa_topology_type {
     NUMA_DIRECT,
     NUMA_GLUELESS_MESH,
     NUMA_BACKPLANE,
 };
 extern enum numa_topology_type sched_numa_topology_type;
 extern int sched_max_numa_distance;
 extern bool find_numa_distance(int distance);
 extern void sched_init_numa(int offline_node);
 extern void sched_update_numa(int cpu, bool online);
 extern void sched_domains_numa_masks_set(unsigned int cpu);
 extern void sched_domains_numa_masks_clear(unsigned int cpu);
 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
 #else
 static inline void sched_init_numa(int offline_node) { }
 static inline void sched_update_numa(int cpu, bool online) { }
 static inline void sched_domains_numa_masks_set(unsigned int cpu) { }
 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { }
 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
 {
     return nr_cpu_ids;
 }
 #endif
 
 #ifdef CONFIG_NUMA_BALANCING
 /* The regions in numa_faults array from task_struct */
 enum numa_faults_stats {
     NUMA_MEM = 0,
     NUMA_CPU,
     NUMA_MEMBUF,
     NUMA_CPUBUF
 };
 extern void sched_setnuma(struct task_struct *p, int node);
 extern int migrate_task_to(struct task_struct *p, int cpu);
 extern int migrate_swap(struct task_struct *p, struct task_struct *t,
             int cpu, int scpu);
 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p);
 #else
 static inline void
 init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
 {
 }
 #endif /* CONFIG_NUMA_BALANCING */
 
 #ifdef CONFIG_SMP
 
 static inline void
 queue_balance_callback(struct rq *rq,
                struct callback_head *head,
                void (*func)(struct rq *rq))
 {
     lockdep_assert_rq_held(rq);
 
     /*
      * Don't (re)queue an already queued item; nor queue anything when
      * balance_push() is active, see the comment with
      * balance_push_callback.
      */
     if (unlikely(head->next || rq->balance_callback == &balance_push_callback))
         return;
 
     head->func = (void (*)(struct callback_head *))func;
     head->next = rq->balance_callback;
     rq->balance_callback = head;
 }
 
 #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 destroy_sched_domains: call_rcu 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)
 
 /**
  * highest_flag_domain - Return highest sched_domain containing flag.
  * @cpu:    The CPU whose highest level of sched domain is to
  *      be returned.
  * @flag:   The flag to check for the highest sched_domain
  *      for the given CPU.
  *
  * Returns the highest sched_domain of a CPU which contains the given flag.
  */
 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;
 }
 
 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
 {
     struct sched_domain *sd;
 
     for_each_domain(cpu, sd) {
         if (sd->flags & flag)
             break;
     }
 
     return sd;
 }
 
 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc);
 DECLARE_PER_CPU(int, sd_llc_size);
 DECLARE_PER_CPU(int, sd_llc_id);
 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);
 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa);
 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
 extern struct static_key_false sched_asym_cpucapacity;
 
 struct sched_group_capacity {
     atomic_t        ref;
     /*
      * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
      * for a single CPU.
      */
     unsigned long       capacity;
     unsigned long       min_capacity;       /* Min per-CPU capacity in group */
     unsigned long       max_capacity;       /* Max per-CPU capacity in group */
     unsigned long       next_update;
     int         imbalance;      /* XXX unrelated to capacity but shared group state */
 
 #ifdef CONFIG_SCHED_DEBUG
     int         id;
 #endif
 
     unsigned long       cpumask[];      /* Balance mask */
 };
 
 struct sched_group {
     struct sched_group  *next;          /* Must be a circular list */
     atomic_t        ref;
 
     unsigned int        group_weight;
     struct sched_group_capacity *sgc;
     int         asym_prefer_cpu;    /* CPU of highest priority in group */
     int         flags;
 
     /*
      * The CPUs this group covers.
      *
      * NOTE: this field is variable length. (Allocated dynamically
      * by attaching extra space to the end of the structure,
      * depending on how many CPUs the kernel has booted up with)
      */
     unsigned long       cpumask[];
 };
 
 static inline struct cpumask *sched_group_span(struct sched_group *sg)
 {
     return to_cpumask(sg->cpumask);
 }
 
 /*
  * See build_balance_mask().
  */
 static inline struct cpumask *group_balance_mask(struct sched_group *sg)
 {
     return to_cpumask(sg->sgc->cpumask);
 }
 
 extern int group_balance_cpu(struct sched_group *sg);
 
 #ifdef CONFIG_SCHED_DEBUG
 void update_sched_domain_debugfs(void);
 void dirty_sched_domain_sysctl(int cpu);
 #else
 static inline void update_sched_domain_debugfs(void)
 {
 }
 static inline void dirty_sched_domain_sysctl(int cpu)
 {
 }
 #endif
 
 extern int sched_update_scaling(void);
 #endif /* CONFIG_SMP */
 
 #include "stats.h"
 
 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS)
 
 extern void __sched_core_account_forceidle(struct rq *rq);
 
 static inline void sched_core_account_forceidle(struct rq *rq)
 {
     if (schedstat_enabled())
         __sched_core_account_forceidle(rq);
 }
 
 extern void __sched_core_tick(struct rq *rq);
 
 static inline void sched_core_tick(struct rq *rq)
 {
     if (sched_core_enabled(rq) && schedstat_enabled())
         __sched_core_tick(rq);
 }
 
 #else
 
 static inline void sched_core_account_forceidle(struct rq *rq) {}
 
 static inline void sched_core_tick(struct rq *rq) {}
 
 #endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */
 
 #ifdef CONFIG_CGROUP_SCHED
 
 /*
  * Return the group to which this tasks belongs.
  *
  * We cannot use task_css() 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
     set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
     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
      * successfully executed on another CPU. We must ensure that updates of
      * per-task data have been completed by this moment.
      */
     smp_wmb();
     WRITE_ONCE(task_thread_info(p)->cpu, cpu);
     p->wake_cpu = cpu;
 #endif
 }
 
 /*
  * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
  */
 #ifdef CONFIG_SCHED_DEBUG
 # define const_debug __read_mostly
 #else
 # define const_debug const
 #endif
 
 #define SCHED_FEAT(name, enabled)   \
     __SCHED_FEAT_##name ,
 
 enum {
 #include "features.h"
     __SCHED_FEAT_NR,
 };
 
 #undef SCHED_FEAT
 
 #ifdef CONFIG_SCHED_DEBUG
 
 /*
  * To support run-time toggling of sched features, all the translation units
  * (but core.c) reference the sysctl_sched_features defined in core.c.
  */
 extern const_debug unsigned int sysctl_sched_features;
 
 #ifdef CONFIG_JUMP_LABEL
 #define SCHED_FEAT(name, enabled)                   \
 static __always_inline bool static_branch_##name(struct static_key *key) \
 {                                   \
     return static_key_##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 /* !CONFIG_JUMP_LABEL */
 
 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
 
 #endif /* CONFIG_JUMP_LABEL */
 
 #else /* !SCHED_DEBUG */
 
 /*
  * Each translation unit has its own copy of sysctl_sched_features to allow
  * constants propagation at compile time and compiler optimization based on
  * features default.
  */
 #define SCHED_FEAT(name, enabled)   \
     (1UL << __SCHED_FEAT_##name) * enabled |
 static const_debug __maybe_unused unsigned int sysctl_sched_features =
 #include "features.h"
     0;
 #undef SCHED_FEAT
 
 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
 
 #endif /* SCHED_DEBUG */
 
 extern struct static_key_false sched_numa_balancing;
 extern struct static_key_false sched_schedstats;
 
 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
 }
 
 static inline int task_on_rq_queued(struct task_struct *p)
 {
     return p->on_rq == TASK_ON_RQ_QUEUED;
 }
 
 static inline int task_on_rq_migrating(struct task_struct *p)
 {
     return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
 }
 
 /* Wake flags. The first three directly map to some SD flag value */
 #define WF_EXEC     0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */
 #define WF_FORK     0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */
 #define WF_TTWU     0x08 /* Wakeup;            maps to SD_BALANCE_WAKE */
 
 #define WF_SYNC     0x10 /* Waker goes to sleep after wakeup */
 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */
 
 #ifdef CONFIG_SMP
 static_assert(WF_EXEC == SD_BALANCE_EXEC);
 static_assert(WF_FORK == SD_BALANCE_FORK);
 static_assert(WF_TTWU == SD_BALANCE_WAKE);
 #endif
 
 /*
  * 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
 
 extern const int        sched_prio_to_weight[40];
 extern const u32        sched_prio_to_wmult[40];
 
 /*
  * {de,en}queue flags:
  *
  * DEQUEUE_SLEEP  - task is no longer runnable
  * ENQUEUE_WAKEUP - task just became runnable
  *
  * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
  *                are in a known state which allows modification. Such pairs
  *                should preserve as much state as possible.
  *
  * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
  *        in the runqueue.
  *
  * ENQUEUE_HEAD      - place at front of runqueue (tail if not specified)
  * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
  * ENQUEUE_MIGRATED  - the task was migrated during wakeup
  *
  */
 
 #define DEQUEUE_SLEEP       0x01
 #define DEQUEUE_SAVE        0x02 /* Matches ENQUEUE_RESTORE */
 #define DEQUEUE_MOVE        0x04 /* Matches ENQUEUE_MOVE */
 #define DEQUEUE_NOCLOCK     0x08 /* Matches ENQUEUE_NOCLOCK */
 
 #define ENQUEUE_WAKEUP      0x01
 #define ENQUEUE_RESTORE     0x02
 #define ENQUEUE_MOVE        0x04
 #define ENQUEUE_NOCLOCK     0x08
 
 #define ENQUEUE_HEAD        0x10
 #define ENQUEUE_REPLENISH   0x20
 #ifdef CONFIG_SMP
 #define ENQUEUE_MIGRATED    0x40
 #else
 #define ENQUEUE_MIGRATED    0x00
 #endif
 
 #define RETRY_TASK      ((void *)-1UL)
 
 struct sched_class {
 
 #ifdef CONFIG_UCLAMP_TASK
     int uclamp_enabled;
 #endif
 
     void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
     void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
     void (*yield_task)   (struct rq *rq);
     bool (*yield_to_task)(struct rq *rq, struct task_struct *p);
 
     void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags);
 
     struct task_struct *(*pick_next_task)(struct rq *rq);
 
     void (*put_prev_task)(struct rq *rq, struct task_struct *p);
     void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
 
 #ifdef CONFIG_SMP
     int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
     int  (*select_task_rq)(struct task_struct *p, int task_cpu, int flags);
 
     struct task_struct * (*pick_task)(struct rq *rq);
 
     void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
 
     void (*task_woken)(struct rq *this_rq, struct task_struct *task);
 
     void (*set_cpus_allowed)(struct task_struct *p,
                  const struct cpumask *newmask,
                  u32 flags);
 
     void (*rq_online)(struct rq *rq);
     void (*rq_offline)(struct rq *rq);
 
     struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq);
 #endif
 
     void (*task_tick)(struct rq *rq, struct task_struct *p, int queued);
     void (*task_fork)(struct task_struct *p);
     void (*task_dead)(struct task_struct *p);
 
     /*
      * The switched_from() call is allowed to drop rq->lock, therefore we
      * cannot assume the switched_from/switched_to pair is serialized by
      * rq->lock. They are however serialized by p->pi_lock.
      */
     void (*switched_from)(struct rq *this_rq, struct task_struct *task);
     void (*switched_to)  (struct rq *this_rq, struct task_struct *task);
     void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
                   int oldprio);
 
     unsigned int (*get_rr_interval)(struct rq *rq,
                     struct task_struct *task);
 
     void (*update_curr)(struct rq *rq);
 
 #define TASK_SET_GROUP      0
 #define TASK_MOVE_GROUP     1
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
     void (*task_change_group)(struct task_struct *p, int type);
 #endif
 };
 
 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
     WARN_ON_ONCE(rq->curr != prev);
     prev->sched_class->put_prev_task(rq, prev);
 }
 
 static inline void set_next_task(struct rq *rq, struct task_struct *next)
 {
     next->sched_class->set_next_task(rq, next, false);
 }
 
 
 /*
  * Helper to define a sched_class instance; each one is placed in a separate
  * section which is ordered by the linker script:
  *
  *   include/asm-generic/vmlinux.lds.h
  *
  * *CAREFUL* they are laid out in *REVERSE* order!!!
  *
  * Also enforce alignment on the instance, not the type, to guarantee layout.
  */
 #define DEFINE_SCHED_CLASS(name) \
 const struct sched_class name##_sched_class \
     __aligned(__alignof__(struct sched_class)) \
     __section("__" #name "_sched_class")
 
 /* Defined in include/asm-generic/vmlinux.lds.h */
 extern struct sched_class __sched_class_highest[];
 extern struct sched_class __sched_class_lowest[];
 
 #define for_class_range(class, _from, _to) \
     for (class = (_from); class < (_to); class++)
 
 #define for_each_class(class) \
     for_class_range(class, __sched_class_highest, __sched_class_lowest)
 
 #define sched_class_above(_a, _b)   ((_a) < (_b))
 
 extern const struct sched_class stop_sched_class;
 extern const struct sched_class dl_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;
 
 static inline bool sched_stop_runnable(struct rq *rq)
 {
     return rq->stop && task_on_rq_queued(rq->stop);
 }
 
 static inline bool sched_dl_runnable(struct rq *rq)
 {
     return rq->dl.dl_nr_running > 0;
 }
 
 static inline bool sched_rt_runnable(struct rq *rq)
 {
     return rq->rt.rt_queued > 0;
 }
 
 static inline bool sched_fair_runnable(struct rq *rq)
 {
     return rq->cfs.nr_running > 0;
 }
 
 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
 extern struct task_struct *pick_next_task_idle(struct rq *rq);
 
 #define SCA_CHECK       0x01
 #define SCA_MIGRATE_DISABLE 0x02
 #define SCA_MIGRATE_ENABLE  0x04
 #define SCA_USER        0x08
 
 #ifdef CONFIG_SMP
 
 extern void update_group_capacity(struct sched_domain *sd, int cpu);
 
 extern void trigger_load_balance(struct rq *rq);
 
 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask, u32 flags);
 
 static inline struct task_struct *get_push_task(struct rq *rq)
 {
     struct task_struct *p = rq->curr;
 
     lockdep_assert_rq_held(rq);
 
     if (rq->push_busy)
         return NULL;
 
     if (p->nr_cpus_allowed == 1)
         return NULL;
 
     if (p->migration_disabled)
         return NULL;
 
     rq->push_busy = true;
     return get_task_struct(p);
 }
 
 extern int push_cpu_stop(void *arg);
 
 #endif
 
 #ifdef CONFIG_CPU_IDLE
 static inline void idle_set_state(struct rq *rq,
                   struct cpuidle_state *idle_state)
 {
     rq->idle_state = idle_state;
 }
 
 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
 {
     SCHED_WARN_ON(!rcu_read_lock_held());
 
     return rq->idle_state;
 }
 #else
 static inline void idle_set_state(struct rq *rq,
                   struct cpuidle_state *idle_state)
 {
 }
 
 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
 {
     return NULL;
 }
 #endif
 
 extern void schedule_idle(void);
 
 extern void sysrq_sched_debug_show(void);
 extern void sched_init_granularity(void);
 extern void update_max_interval(void);
 
 extern void init_sched_dl_class(void);
 extern void init_sched_rt_class(void);
 extern void init_sched_fair_class(void);
 
 extern void reweight_task(struct task_struct *p, int prio);
 
 extern void resched_curr(struct rq *rq);
 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 bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
 
 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
 
 #define BW_SHIFT        20
 #define BW_UNIT         (1 << BW_SHIFT)
 #define RATIO_SHIFT     8
 #define MAX_BW_BITS     (64 - BW_SHIFT)
 #define MAX_BW          ((1ULL << MAX_BW_BITS) - 1)
 unsigned long to_ratio(u64 period, u64 runtime);
 
 extern void init_entity_runnable_average(struct sched_entity *se);
 extern void post_init_entity_util_avg(struct task_struct *p);
 
 #ifdef CONFIG_NO_HZ_FULL
 extern bool sched_can_stop_tick(struct rq *rq);
 extern int __init sched_tick_offload_init(void);
 
 /*
  * Tick may be needed by tasks in the runqueue depending on their policy and
  * requirements. If tick is needed, lets send the target an IPI to kick it out of
  * nohz mode if necessary.
  */
 static inline void sched_update_tick_dependency(struct rq *rq)
 {
     int cpu = cpu_of(rq);
 
     if (!tick_nohz_full_cpu(cpu))
         return;
 
     if (sched_can_stop_tick(rq))
         tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
     else
         tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
 }
 #else
 static inline int sched_tick_offload_init(void) { return 0; }
 static inline void sched_update_tick_dependency(struct rq *rq) { }
 #endif
 
 static inline void add_nr_running(struct rq *rq, unsigned count)
 {
     unsigned prev_nr = rq->nr_running;
 
     rq->nr_running = prev_nr + count;
     if (trace_sched_update_nr_running_tp_enabled()) {
         call_trace_sched_update_nr_running(rq, count);
     }
 
 #ifdef CONFIG_SMP
     if (prev_nr < 2 && rq->nr_running >= 2) {
         if (!READ_ONCE(rq->rd->overload))
             WRITE_ONCE(rq->rd->overload, 1);
     }
 #endif
 
     sched_update_tick_dependency(rq);
 }
 
 static inline void sub_nr_running(struct rq *rq, unsigned count)
 {
     rq->nr_running -= count;
     if (trace_sched_update_nr_running_tp_enabled()) {
         call_trace_sched_update_nr_running(rq, -count);
     }
 
     /* Check if we still need preemption */
     sched_update_tick_dependency(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_nr_migrate;
 extern const_debug unsigned int sysctl_sched_migration_cost;
 
 #ifdef CONFIG_SCHED_DEBUG
 extern unsigned int sysctl_sched_latency;
 extern unsigned int sysctl_sched_min_granularity;
 extern unsigned int sysctl_sched_idle_min_granularity;
 extern unsigned int sysctl_sched_wakeup_granularity;
 extern int sysctl_resched_latency_warn_ms;
 extern int sysctl_resched_latency_warn_once;
 
 extern unsigned int sysctl_sched_tunable_scaling;
 
 extern unsigned int sysctl_numa_balancing_scan_delay;
 extern unsigned int sysctl_numa_balancing_scan_period_min;
 extern unsigned int sysctl_numa_balancing_scan_period_max;
 extern unsigned int sysctl_numa_balancing_scan_size;
 #endif
 
 #ifdef CONFIG_SCHED_HRTICK
 
 /*
  * Use hrtick when:
  *  - enabled by features
  *  - hrtimer is actually high res
  */
 static inline int hrtick_enabled(struct rq *rq)
 {
     if (!cpu_active(cpu_of(rq)))
         return 0;
     return hrtimer_is_hres_active(&rq->hrtick_timer);
 }
 
 static inline int hrtick_enabled_fair(struct rq *rq)
 {
     if (!sched_feat(HRTICK))
         return 0;
     return hrtick_enabled(rq);
 }
 
 static inline int hrtick_enabled_dl(struct rq *rq)
 {
     if (!sched_feat(HRTICK_DL))
         return 0;
     return hrtick_enabled(rq);
 }
 
 void hrtick_start(struct rq *rq, u64 delay);
 
 #else
 
 static inline int hrtick_enabled_fair(struct rq *rq)
 {
     return 0;
 }
 
 static inline int hrtick_enabled_dl(struct rq *rq)
 {
     return 0;
 }
 
 static inline int hrtick_enabled(struct rq *rq)
 {
     return 0;
 }
 
 #endif /* CONFIG_SCHED_HRTICK */
 
 #ifndef arch_scale_freq_tick
 static __always_inline
 void arch_scale_freq_tick(void)
 {
 }
 #endif
 
 #ifndef arch_scale_freq_capacity
 /**
  * arch_scale_freq_capacity - get the frequency scale factor of a given CPU.
  * @cpu: the CPU in question.
  *
  * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e.
  *
  *     f_curr
  *     ------ * SCHED_CAPACITY_SCALE
  *     f_max
  */
 static __always_inline
 unsigned long arch_scale_freq_capacity(int cpu)
 {
     return SCHED_CAPACITY_SCALE;
 }
 #endif
 
 #ifdef CONFIG_SCHED_DEBUG
 /*
  * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to
  * acquire rq lock instead of rq_lock(). So at the end of these two functions
  * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of
  * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning.
  */
 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2)
 {
     rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
     /* rq1 == rq2 for !CONFIG_SMP, so just clear RQCF_UPDATED once. */
 #ifdef CONFIG_SMP
     rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
 #endif
 }
 #else
 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {}
 #endif
 
 #ifdef CONFIG_SMP
 
 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2)
 {
 #ifdef CONFIG_SCHED_CORE
     /*
      * In order to not have {0,2},{1,3} turn into into an AB-BA,
      * order by core-id first and cpu-id second.
      *
      * Notably:
      *
      *  double_rq_lock(0,3); will take core-0, core-1 lock
      *  double_rq_lock(1,2); will take core-1, core-0 lock
      *
      * when only cpu-id is considered.
      */
     if (rq1->core->cpu < rq2->core->cpu)
         return true;
     if (rq1->core->cpu > rq2->core->cpu)
         return false;
 
     /*
      * __sched_core_flip() relies on SMT having cpu-id lock order.
      */
 #endif
     return rq1->cpu < rq2->cpu;
 }
 
 extern void double_rq_lock(struct rq *rq1, struct rq *rq2);
 
 #ifdef CONFIG_PREEMPTION
 
 /*
  * 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_rq_unlock(this_rq);
     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)
 {
     if (__rq_lockp(this_rq) == __rq_lockp(busiest) ||
         likely(raw_spin_rq_trylock(busiest))) {
         double_rq_clock_clear_update(this_rq, busiest);
         return 0;
     }
 
     if (rq_order_less(this_rq, busiest)) {
         raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING);
         double_rq_clock_clear_update(this_rq, busiest);
         return 0;
     }
 
     raw_spin_rq_unlock(this_rq);
     double_rq_lock(this_rq, busiest);
 
     return 1;
 }
 
 #endif /* CONFIG_PREEMPTION */
 
 /*
  * 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)
 {
     lockdep_assert_irqs_disabled();
 
     return _double_lock_balance(this_rq, busiest);
 }
 
 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
     __releases(busiest->lock)
 {
     if (__rq_lockp(this_rq) != __rq_lockp(busiest))
         raw_spin_rq_unlock(busiest);
     lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_);
 }
 
 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
 {
     if (l1 > l2)
         swap(l1, l2);
 
     spin_lock(l1);
     spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
 }
 
 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
 {
     if (l1 > l2)
         swap(l1, l2);
 
     spin_lock_irq(l1);
     spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
 }
 
 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
 {
     if (l1 > l2)
         swap(l1, l2);
 
     raw_spin_lock(l1);
     raw_spin_lock_nested(l2, 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)
 {
     if (__rq_lockp(rq1) != __rq_lockp(rq2))
         raw_spin_rq_unlock(rq2);
     else
         __release(rq2->lock);
     raw_spin_rq_unlock(rq1);
 }
 
 extern void set_rq_online (struct rq *rq);
 extern void set_rq_offline(struct rq *rq);
 extern bool sched_smp_initialized;
 
 #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_rq_lock(rq1);
     __acquire(rq2->lock);   /* Fake it out ;) */
     double_rq_clock_clear_update(rq1, rq2);
 }
 
 /*
  * 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_rq_unlock(rq1);
     __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);
 
 #ifdef  CONFIG_SCHED_DEBUG
 extern bool sched_debug_verbose;
 
 extern void print_cfs_stats(struct seq_file *m, int cpu);
 extern void print_rt_stats(struct seq_file *m, int cpu);
 extern void print_dl_stats(struct seq_file *m, int cpu);
 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
 
 extern void resched_latency_warn(int cpu, u64 latency);
 #ifdef CONFIG_NUMA_BALANCING
 extern void
 show_numa_stats(struct task_struct *p, struct seq_file *m);
 extern void
 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
     unsigned long tpf, unsigned long gsf, unsigned long gpf);
 #endif /* CONFIG_NUMA_BALANCING */
 #else
 static inline void resched_latency_warn(int cpu, u64 latency) {}
 #endif /* CONFIG_SCHED_DEBUG */
 
 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
 extern void init_rt_rq(struct rt_rq *rt_rq);
 extern void init_dl_rq(struct dl_rq *dl_rq);
 
 extern void cfs_bandwidth_usage_inc(void);
 extern void cfs_bandwidth_usage_dec(void);
 
 #ifdef CONFIG_NO_HZ_COMMON
 #define NOHZ_BALANCE_KICK_BIT   0
 #define NOHZ_STATS_KICK_BIT 1
 #define NOHZ_NEWILB_KICK_BIT    2
 #define NOHZ_NEXT_KICK_BIT  3
 
 /* Run rebalance_domains() */
 #define NOHZ_BALANCE_KICK   BIT(NOHZ_BALANCE_KICK_BIT)
 /* Update blocked load */
 #define NOHZ_STATS_KICK     BIT(NOHZ_STATS_KICK_BIT)
 /* Update blocked load when entering idle */
 #define NOHZ_NEWILB_KICK    BIT(NOHZ_NEWILB_KICK_BIT)
 /* Update nohz.next_balance */
 #define NOHZ_NEXT_KICK      BIT(NOHZ_NEXT_KICK_BIT)
 
 #define NOHZ_KICK_MASK  (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK)
 
 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
 
 extern void nohz_balance_exit_idle(struct rq *rq);
 #else
 static inline void nohz_balance_exit_idle(struct rq *rq) { }
 #endif
 
 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 extern void nohz_run_idle_balance(int cpu);
 #else
 static inline void nohz_run_idle_balance(int cpu) { }
 #endif
 
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 struct irqtime {
     u64         total;
     u64         tick_delta;
     u64         irq_start_time;
     struct u64_stats_sync   sync;
 };
 
 DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
 
 /*
  * Returns the irqtime minus the softirq time computed by ksoftirqd.
  * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime
  * and never move forward.
  */
 static inline u64 irq_time_read(int cpu)
 {
     struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
     unsigned int seq;
     u64 total;
 
     do {
         seq = __u64_stats_fetch_begin(&irqtime->sync);
         total = irqtime->total;
     } while (__u64_stats_fetch_retry(&irqtime->sync, seq));
 
     return total;
 }
 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
 
 #ifdef CONFIG_CPU_FREQ
 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
 
 /**
  * cpufreq_update_util - Take a note about CPU utilization changes.
  * @rq: Runqueue to carry out the update for.
  * @flags: Update reason flags.
  *
  * This function is called by the scheduler on the CPU whose utilization is
  * being updated.
  *
  * It can only be called from RCU-sched read-side critical sections.
  *
  * The way cpufreq is currently arranged requires it to evaluate the CPU
  * performance state (frequency/voltage) on a regular basis to prevent it from
  * being stuck in a completely inadequate performance level for too long.
  * That is not guaranteed to happen if the updates are only triggered from CFS
  * and DL, though, because they may not be coming in if only RT tasks are
  * active all the time (or there are RT tasks only).
  *
  * As a workaround for that issue, this function is called periodically by the
  * RT sched class to trigger extra cpufreq updates to prevent it from stalling,
  * but that really is a band-aid.  Going forward it should be replaced with
  * solutions targeted more specifically at RT tasks.
  */
 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
 {
     struct update_util_data *data;
 
     data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data,
                           cpu_of(rq)));
     if (data)
         data->func(data, rq_clock(rq), flags);
 }
 #else
 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
 #endif /* CONFIG_CPU_FREQ */
 
 #ifdef arch_scale_freq_capacity
 # ifndef arch_scale_freq_invariant
 #  define arch_scale_freq_invariant()   true
 # endif
 #else
 # define arch_scale_freq_invariant()    false
 #endif
 
 #ifdef CONFIG_SMP
 static inline unsigned long capacity_orig_of(int cpu)
 {
     return cpu_rq(cpu)->cpu_capacity_orig;
 }
 
 /**
  * enum cpu_util_type - CPU utilization type
  * @FREQUENCY_UTIL: Utilization used to select frequency
  * @ENERGY_UTIL:    Utilization used during energy calculation
  *
  * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time
  * need to be aggregated differently depending on the usage made of them. This
  * enum is used within effective_cpu_util() to differentiate the types of
  * utilization expected by the callers, and adjust the aggregation accordingly.
  */
 enum cpu_util_type {
     FREQUENCY_UTIL,
     ENERGY_UTIL,
 };
 
 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
                  enum cpu_util_type type,
                  struct task_struct *p);
 
 static inline unsigned long cpu_bw_dl(struct rq *rq)
 {
     return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
 }
 
 static inline unsigned long cpu_util_dl(struct rq *rq)
 {
     return READ_ONCE(rq->avg_dl.util_avg);
 }
 
 /**
  * cpu_util_cfs() - Estimates the amount of CPU capacity used by CFS tasks.
  * @cpu: the CPU to get the utilization for.
  *
  * The unit of the return value must be the same as the one of CPU capacity
  * so that CPU utilization can be compared with CPU capacity.
  *
  * CPU utilization is the sum of running time of runnable tasks plus the
  * recent utilization of currently non-runnable tasks on that CPU.
  * It represents the amount of CPU capacity currently used by CFS tasks in
  * the range [0..max CPU capacity] with max CPU capacity being the CPU
  * capacity at f_max.
  *
  * The estimated CPU utilization is defined as the maximum between CPU
  * utilization and sum of the estimated utilization of the currently
  * runnable tasks on that CPU. It preserves a utilization "snapshot" of
  * previously-executed tasks, which helps better deduce how busy a CPU will
  * be when a long-sleeping task wakes up. The contribution to CPU utilization
  * of such a task would be significantly decayed at this point of time.
  *
  * CPU utilization can be higher than the current CPU capacity
  * (f_curr/f_max * max CPU capacity) or even the max CPU capacity because
  * of rounding errors as well as task migrations or wakeups of new tasks.
  * CPU utilization has to be capped to fit into the [0..max CPU capacity]
  * range. Otherwise a group of CPUs (CPU0 util = 121% + CPU1 util = 80%)
  * could be seen as over-utilized even though CPU1 has 20% of spare CPU
  * capacity. CPU utilization is allowed to overshoot current CPU capacity
  * though since this is useful for predicting the CPU capacity required
  * after task migrations (scheduler-driven DVFS).
  *
  * Return: (Estimated) utilization for the specified CPU.
  */
 static inline unsigned long cpu_util_cfs(int cpu)
 {
     struct cfs_rq *cfs_rq;
     unsigned long util;
 
     cfs_rq = &cpu_rq(cpu)->cfs;
     util = READ_ONCE(cfs_rq->avg.util_avg);
 
     if (sched_feat(UTIL_EST)) {
         util = max_t(unsigned long, util,
                  READ_ONCE(cfs_rq->avg.util_est.enqueued));
     }
 
     return min(util, capacity_orig_of(cpu));
 }
 
 static inline unsigned long cpu_util_rt(struct rq *rq)
 {
     return READ_ONCE(rq->avg_rt.util_avg);
 }
 #endif
 
 #ifdef CONFIG_UCLAMP_TASK
 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
 
 /**
  * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values.
  * @rq:     The rq to clamp against. Must not be NULL.
  * @util:   The util value to clamp.
  * @p:      The task to clamp against. Can be NULL if you want to clamp
  *      against @rq only.
  *
  * Clamps the passed @util to the max(@rq, @p) effective uclamp values.
  *
  * If sched_uclamp_used static key is disabled, then just return the util
  * without any clamping since uclamp aggregation at the rq level in the fast
  * path is disabled, rendering this operation a NOP.
  *
  * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It
  * will return the correct effective uclamp value of the task even if the
  * static key is disabled.
  */
 static __always_inline
 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
                   struct task_struct *p)
 {
     unsigned long min_util = 0;
     unsigned long max_util = 0;
 
     if (!static_branch_likely(&sched_uclamp_used))
         return util;
 
     if (p) {
         min_util = uclamp_eff_value(p, UCLAMP_MIN);
         max_util = uclamp_eff_value(p, UCLAMP_MAX);
 
         /*
          * Ignore last runnable task's max clamp, as this task will
          * reset it. Similarly, no need to read the rq's min clamp.
          */
         if (rq->uclamp_flags & UCLAMP_FLAG_IDLE)
             goto out;
     }
 
     min_util = max_t(unsigned long, min_util, READ_ONCE(rq->uclamp[UCLAMP_MIN].value));
     max_util = max_t(unsigned long, max_util, READ_ONCE(rq->uclamp[UCLAMP_MAX].value));
 out:
     /*
      * Since CPU's {min,max}_util clamps are MAX aggregated considering
      * RUNNABLE tasks with _different_ clamps, we can end up with an
      * inversion. Fix it now when the clamps are applied.
      */
     if (unlikely(min_util >= max_util))
         return min_util;
 
     return clamp(util, min_util, max_util);
 }
 
 /* Is the rq being capped/throttled by uclamp_max? */
 static inline bool uclamp_rq_is_capped(struct rq *rq)
 {
     unsigned long rq_util;
     unsigned long max_util;
 
     if (!static_branch_likely(&sched_uclamp_used))
         return false;
 
     rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq);
     max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
 
     return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util;
 }
 
 /*
  * When uclamp is compiled in, the aggregation at rq level is 'turned off'
  * by default in the fast path and only gets turned on once userspace performs
  * an operation that requires it.
  *
  * Returns true if userspace opted-in to use uclamp and aggregation at rq level
  * hence is active.
  */
 static inline bool uclamp_is_used(void)
 {
     return static_branch_likely(&sched_uclamp_used);
 }
 #else /* CONFIG_UCLAMP_TASK */
 static inline
 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
                   struct task_struct *p)
 {
     return util;
 }
 
 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; }
 
 static inline bool uclamp_is_used(void)
 {
     return false;
 }
 #endif /* CONFIG_UCLAMP_TASK */
 
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
 static inline unsigned long cpu_util_irq(struct rq *rq)
 {
     return rq->avg_irq.util_avg;
 }
 
 static inline
 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
 {
     util *= (max - irq);
     util /= max;
 
     return util;
 
 }
 #else
 static inline unsigned long cpu_util_irq(struct rq *rq)
 {
     return 0;
 }
 
 static inline
 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
 {
     return util;
 }
 #endif
 
 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
 
 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))
 
 DECLARE_STATIC_KEY_FALSE(sched_energy_present);
 
 static inline bool sched_energy_enabled(void)
 {
     return static_branch_unlikely(&sched_energy_present);
 }
 
 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */
 
 #define perf_domain_span(pd) NULL
 static inline bool sched_energy_enabled(void) { return false; }
 
 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
 
 #ifdef CONFIG_MEMBARRIER
 /*
  * The scheduler provides memory barriers required by membarrier between:
  * - prior user-space memory accesses and store to rq->membarrier_state,
  * - store to rq->membarrier_state and following user-space memory accesses.
  * In the same way it provides those guarantees around store to rq->curr.
  */
 static inline void membarrier_switch_mm(struct rq *rq,
                     struct mm_struct *prev_mm,
                     struct mm_struct *next_mm)
 {
     int membarrier_state;
 
     if (prev_mm == next_mm)
         return;
 
     membarrier_state = atomic_read(&next_mm->membarrier_state);
     if (READ_ONCE(rq->membarrier_state) == membarrier_state)
         return;
 
     WRITE_ONCE(rq->membarrier_state, membarrier_state);
 }
 #else
 static inline void membarrier_switch_mm(struct rq *rq,
                     struct mm_struct *prev_mm,
                     struct mm_struct *next_mm)
 {
 }
 #endif
 
 #ifdef CONFIG_SMP
 static inline bool is_per_cpu_kthread(struct task_struct *p)
 {
     if (!(p->flags & PF_KTHREAD))
         return false;
 
     if (p->nr_cpus_allowed != 1)
         return false;
 
     return true;
 }
 #endif
 
 extern void swake_up_all_locked(struct swait_queue_head *q);
 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
 
 #ifdef CONFIG_PREEMPT_DYNAMIC
 extern int preempt_dynamic_mode;
 extern int sched_dynamic_mode(const char *str);
 extern void sched_dynamic_update(int mode);
 #endif
 
 #endif /* _KERNEL_SCHED_SCHED_H */