struct cfs_rq结构体成员解析

struct sched_avg {
    /*
     * These sums represent an infinite geometric series and so are bound
     * above by 1024/(1-y). Thus we only need a u32 to store them for all
     * choices of y < 1-2^(-32)*1024.
     */
    u32 runnable_avg_sum, runnable_avg_period;  /* 前一个：调度实体累计负载均衡值（不包括未进入运行队列期间的负载均衡值）；后一个：调度实体累计负载均衡值 */
    u64 last_runnable_update;  /* 最近一次更新负载均衡值的时间，用ns表示 */
    s64 decay_count;  /* 记录上次该调度实体离开cfs队列的时间，以ms为单位 */
    unsigned long load_avg_contrib;  /* 该调度实体对它所属的CFS_RQ队列的负载均衡贡献值 */
};

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;

#ifdef    CONFIG_SMP
    atomic_long_t load_avg;
    atomic_t runnable_avg;
#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;
};

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

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

    struct rb_root tasks_timeline;
    struct rb_node *rb_leftmost;

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

#ifdef    CONFIG_SCHED_DEBUG
    unsigned int nr_spread_over;
#endif

#ifdef CONFIG_SMP
    /*
     * CFS Load tracking
     * Under CFS, load is tracked on a per-entity basis and aggregated up.
     * This allows for the description of both thread and group usage (in
     * the FAIR_GROUP_SCHED case).
     */
    unsigned long runnable_load_avg, blocked_load_avg;  /* 前一个：进入到运行队列的调度实体负载均衡总和  后一个：未进入运行队列且被阻塞无法再被调度的实体负载均衡总和 */
    atomic64_t decay_counter;  /* 该cfs队列的累计运行时间，以ms为单位 */
    u64 last_decay;  /* 最近一次进行负载均衡计算的时间点，以ms为单位，注意前面说过1024us是计算负载均衡的周期时间 */
    atomic_long_t removed_load;  /* 阻塞部分的调度实体可能有一些已经离开该cfs队列了，此处记录离开部分的负载均衡，在定期更新的时候会从blocked_load_avg中减去 */

#ifdef CONFIG_FAIR_GROUP_SCHED
    /* Required to track per-cpu representation of a task_group */
    u32 tg_runnable_contrib;  /* 该CFS队列对它所属的TG组的运行时负载贡献值 */
    unsigned long tg_load_contrib;  /* 该CFS队列对它所属的TG组的总负载贡献值，包括 runnable_load_avg, blocked_load_avg*/

    /*
     * 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 */

#ifdef CONFIG_CFS_BANDWIDTH
    int runtime_enabled;
    u64 runtime_expires;
    s64 runtime_remaining;

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