重要的 CFS 数据结构

struct task_struct { /* Defined in 2.6.23:/usr/include/linux/sched.h */
....
-   struct prio_array *array;
+  struct sched_entity se;
+  struct sched_class *sched_class;
....
....
};

struct sched_entity { /* Defined in 2.6.23:/usr/include/linux/sched.h */
long wait_runtime;   /* Amount of time the entity must run to become completely */
/* fair and balanced.*/
s64 fair_key;
struct load_weight   load;         /* for load-balancing */
struct rb_node run_node;            /* To be part of Red-black tree data structure */
unsigned int on_rq;
....
};

struct sched_class { /* Defined in 2.6.23:/usr/include/linux/sched.h */
struct sched_class *next;
void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
void (*yield_task) (struct rq *rq, struct task_struct *p);

void (*check_preempt_curr) (struct rq *rq, struct task_struct *p);

struct task_struct * (*pick_next_task) (struct rq *rq);
void (*put_prev_task) (struct rq *rq, struct task_struct *p);

unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
struct rq *busiest,
unsigned long max_nr_move, unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio);

void (*set_curr_task) (struct rq *rq);
void (*task_tick) (struct rq *rq, struct task_struct *p);
void (*task_new) (struct rq *rq, struct task_struct *p);
};

struct cfs_rq {/* Defined in 2.6.23:kernel/sched.c */
struct load_weight load;
unsigned long nr_running;

s64 fair_clock; /* runqueue wide global clock */
u64 exec_clock;
s64 wait_runtime;
u64 sleeper_bonus;
unsigned long wait_runtime_overruns, wait_runtime_underruns;

struct rb_root tasks_timeline; /* Points to the root of the rb-tree*/
struct rb_node *rb_leftmost; /* Points to most eligible task to give the CPU */
struct rb_node *rb_load_balance_curr;
#ifdef CONFIG_FAIR_GROUP_SCHED
struct sched_entity *curr; /* Currently running entity */
struct rq *rq;      /* cpu runqueue to which this cfs_rq is attached */
...
...
#endif
};

[root@dodge ~]# sysctl -A|grep "sched" | grep -v "domain"
kernel.sched_min_granularity_ns = 4000000
kernel.sched_latency_ns = 40000000
kernel.sched_wakeup_granularity_ns = 2000000
kernel.sched_batch_wakeup_granularity_ns = 25000000
kernel.sched_stat_granularity_ns = 0
kernel.sched_runtime_limit_ns = 40000000
kernel.sched_child_runs_first = 1
kernel.sched_features = 29
kernel.sched_compat_yield = 0
[root@dodge ~]#

struct sched_entity { /* Defined in /usr/include/linux/sched.h */
- long    wait_runtime;
- s64     fair_key;
+ u64     vruntime;
- u64     wait_start_fair;
- u64     sleep_start_fair;
...
...
}

struct cfs_rq { /* Defined in kernel/sched.c */
-         s64 fair_clock;
-         s64 wait_runtime;
-         u64 sleeper_bonus;
-         unsigned long wait_runtime_overruns, wait_runtime_underruns;
+        u64 min_vruntime;

+        struct sched_entity *curr;

+#ifdef CONFIG_FAIR_GROUP_SCHED
...
+        struct task_group *tg;    /* group that "owns" this runqueue */
...
#endif
};

struct task_group { /* Defined in kernel/sched.c */
#ifdef CONFIG_FAIR_CGROUP_SCHED
struct cgroup_subsys_state css;
#endif
/* 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;
/* spinlock to serialize modification to shares */
spinlock_t lock;
struct rcu_head rcu;
};