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 <[email protected]> cc: Peter Zijlstra <[email protected]> Signed-off-by: Morten Rasmussen <[email protected]> --- 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 090223f..adf64df 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2778,6 +2778,15 @@ 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 */ @@ -2813,6 +2822,8 @@ 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); } } @@ -2830,14 +2841,20 @@ 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; } @@ -2884,6 +2901,8 @@ 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); } @@ -2910,6 +2929,8 @@ 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 */ } @@ -4929,6 +4950,8 @@ 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); } /* We have migrated, no longer consider this task hot */ @@ -7944,6 +7967,8 @@ 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 } @@ -8003,6 +8028,7 @@ 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 } @@ -8055,6 +8081,8 @@ static void task_move_group_fair(struct task_struct *p, int queued) */ 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 e402133..208237f 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -368,11 +368,15 @@ 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 */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
