diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0241b1b55a04..729e7fc7634b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1611,10 +1611,6 @@ static void __sched_fork(struct task_struct *p) p->se.vruntime = 0; INIT_LIST_HEAD(&p->se.group_node); -#ifdef CONFIG_SMP - p->se.avg.runnable_avg_period = 0; - p->se.avg.runnable_avg_sum = 0; -#endif #ifdef CONFIG_SCHEDSTATS memset(&p->se.statistics, 0, sizeof(p->se.statistics)); #endif @@ -1758,6 +1754,8 @@ void wake_up_new_task(struct task_struct *p) set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); #endif + /* Initialize new task's runnable average */ + init_task_runnable_average(p); rq = __task_rq_lock(p); activate_task(rq, p, 0); p->on_rq = 1; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 36eadaaa4e5b..e1602a0fdbf8 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -680,6 +680,26 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) return calc_delta_fair(sched_slice(cfs_rq, se), se); } +#ifdef CONFIG_SMP +static inline void __update_task_entity_contrib(struct sched_entity *se); + +/* Give new task start runnable values to heavy its load in infant time */ +void init_task_runnable_average(struct task_struct *p) +{ + u32 slice; + + p->se.avg.decay_count = 0; + slice = sched_slice(task_cfs_rq(p), &p->se) >> 10; + p->se.avg.runnable_avg_sum = slice; + p->se.avg.runnable_avg_period = slice; + __update_task_entity_contrib(&p->se); +} +#else +void init_task_runnable_average(struct task_struct *p) +{ +} +#endif + /* * Update the current task's runtime statistics. Skip current tasks that * are not in our scheduling class. @@ -1527,6 +1547,10 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, * We track migrations using entity decay_count <= 0, on a wake-up * migration we use a negative decay count to track the remote decays * accumulated while sleeping. + * + * Newly forked tasks are enqueued with se->avg.decay_count == 0, they + * are seen by enqueue_entity_load_avg() as a migration with an already + * constructed load_avg_contrib. */ if (unlikely(se->avg.decay_count <= 0)) { se->avg.last_runnable_update = rq_clock_task(rq_of(cfs_rq)); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 31d25f80a7c6..9c65d46504b1 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1048,6 +1048,8 @@ extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime extern void update_idle_cpu_load(struct rq *this_rq); +extern void init_task_runnable_average(struct task_struct *p); + #ifdef CONFIG_PARAVIRT static inline u64 steal_ticks(u64 steal) {