From f3c0c2d50a775d19e5d5f286e61439d863ef2f9c Mon Sep 17 00:00:00 2001 From: Morten Rasmussen Date: Tue, 23 Sep 2014 15:49:09 +0100 Subject: sched: Track blocked utilization contributions Introduces the blocked utilization, the utilization counter-part to cfs_rq->utilization_load_avg. It is the sum of sched_entity utilization contributions of entities that were recently on the cfs_rq that are currently blocked. Combined with sum of contributions of entities currently on the cfs_rq or currently running (cfs_rq->utilization_load_avg) this can provide a more stable average view of the cpu usage. cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Morten Rasmussen --- kernel/sched/fair.c | 30 +++++++++++++++++++++++++++++- kernel/sched/sched.h | 8 ++++++-- 2 files changed, 35 insertions(+), 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 05e5562c6bdc..81f11427e9b1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2499,6 +2499,15 @@ static inline void subtract_blocked_load_contrib(struct cfs_rq *cfs_rq, cfs_rq->blocked_load_avg = 0; } +static inline void subtract_utilization_blocked_contrib(struct cfs_rq *cfs_rq, + long utilization_contrib) +{ + if (likely(utilization_contrib < cfs_rq->utilization_blocked_avg)) + cfs_rq->utilization_blocked_avg -= utilization_contrib; + else + cfs_rq->utilization_blocked_avg = 0; +} + static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq); /* Update a sched_entity's runnable average */ @@ -2534,6 +2543,8 @@ static inline void update_entity_load_avg(struct sched_entity *se, cfs_rq->utilization_load_avg += utilization_delta; } else { subtract_blocked_load_contrib(cfs_rq, -contrib_delta); + subtract_utilization_blocked_contrib(cfs_rq, + -utilization_delta); } } @@ -2551,14 +2562,20 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update) return; if (atomic_long_read(&cfs_rq->removed_load)) { - unsigned long removed_load; + unsigned long removed_load, removed_utilization; removed_load = atomic_long_xchg(&cfs_rq->removed_load, 0); + removed_utilization = + atomic_long_xchg(&cfs_rq->removed_utilization, 0); subtract_blocked_load_contrib(cfs_rq, removed_load); + subtract_utilization_blocked_contrib(cfs_rq, + removed_utilization); } if (decays) { cfs_rq->blocked_load_avg = decay_load(cfs_rq->blocked_load_avg, decays); + cfs_rq->utilization_blocked_avg = + decay_load(cfs_rq->utilization_blocked_avg, decays); atomic64_add(decays, &cfs_rq->decay_counter); cfs_rq->last_decay = now; } @@ -2605,6 +2622,8 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, /* migrated tasks did not contribute to our blocked load */ if (wakeup) { subtract_blocked_load_contrib(cfs_rq, se->avg.load_avg_contrib); + subtract_utilization_blocked_contrib(cfs_rq, + se->avg.utilization_avg_contrib); update_entity_load_avg(se, 0); } @@ -2631,6 +2650,8 @@ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq, cfs_rq->utilization_load_avg -= se->avg.utilization_avg_contrib; if (sleep) { cfs_rq->blocked_load_avg += se->avg.load_avg_contrib; + cfs_rq->utilization_blocked_avg += + se->avg.utilization_avg_contrib; se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter); } /* migrations, e.g. sleep=0 leave decay_count == 0 */ } @@ -4644,6 +4665,8 @@ migrate_task_rq_fair(struct task_struct *p, int next_cpu) se->avg.decay_count = -__synchronize_entity_decay(se); atomic_long_add(se->avg.load_avg_contrib, &cfs_rq->removed_load); + atomic_long_add(se->avg.utilization_avg_contrib, + &cfs_rq->removed_utilization); } } #endif /* CONFIG_SMP */ @@ -7404,6 +7427,8 @@ static void switched_from_fair(struct rq *rq, struct task_struct *p) if (se->avg.decay_count) { __synchronize_entity_decay(se); subtract_blocked_load_contrib(cfs_rq, se->avg.load_avg_contrib); + subtract_utilization_blocked_contrib(cfs_rq, + se->avg.utilization_avg_contrib); } #endif } @@ -7463,6 +7488,7 @@ void init_cfs_rq(struct cfs_rq *cfs_rq) #ifdef CONFIG_SMP atomic64_set(&cfs_rq->decay_counter, 1); atomic_long_set(&cfs_rq->removed_load, 0); + atomic_long_set(&cfs_rq->removed_utilization, 0); #endif } @@ -7515,6 +7541,8 @@ static void task_move_group_fair(struct task_struct *p, int on_rq) */ se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter); cfs_rq->blocked_load_avg += se->avg.load_avg_contrib; + cfs_rq->utilization_blocked_avg += + se->avg.utilization_avg_contrib; #endif } } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 12d0efabc2dd..d76c74328179 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -264,11 +264,15 @@ struct cfs_rq { * the blocked sched_entities on the rq. * utilization_load_avg is the sum of the average running time of the * sched_entities on the rq. + * utilization_blocked_avg is the utilization equivalent of + * blocked_load_avg, i.e. the sum of running contributions of blocked + * sched_entities associated with the rq. */ - unsigned long runnable_load_avg, blocked_load_avg, utilization_load_avg; + unsigned long runnable_load_avg, blocked_load_avg; + unsigned long utilization_load_avg, utilization_blocked_avg; atomic64_t decay_counter; u64 last_decay; - atomic_long_t removed_load; + atomic_long_t removed_load, removed_utilization; #ifdef CONFIG_FAIR_GROUP_SCHED /* Required to track per-cpu representation of a task_group */ -- cgit v1.2.3