From 2dac754e10a5d41d94d2d2365c0345d4f215a266 Mon Sep 17 00:00:00 2001 From: Paul Turner Date: Thu, 4 Oct 2012 13:18:30 +0200 Subject: sched: Aggregate load contributed by task entities on parenting cfs_rq For a given task t, we can compute its contribution to load as: task_load(t) = runnable_avg(t) * weight(t) On a parenting cfs_rq we can then aggregate: runnable_load(cfs_rq) = \Sum task_load(t), for all runnable children t Maintain this bottom up, with task entities adding their contributed load to the parenting cfs_rq sum. When a task entity's load changes we add the same delta to the maintained sum. Signed-off-by: Paul Turner Reviewed-by: Ben Segall Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20120823141506.514678907@google.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 47 insertions(+), 4 deletions(-) (limited to 'kernel/sched/fair.c') diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8c5468fcf10..77af759e567 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1081,20 +1081,63 @@ static __always_inline int __update_entity_runnable_avg(u64 now, return decayed; } +/* Compute the current contribution to load_avg by se, return any delta */ +static long __update_entity_load_avg_contrib(struct sched_entity *se) +{ + long old_contrib = se->avg.load_avg_contrib; + + if (!entity_is_task(se)) + return 0; + + se->avg.load_avg_contrib = div64_u64(se->avg.runnable_avg_sum * + se->load.weight, + se->avg.runnable_avg_period + 1); + + return se->avg.load_avg_contrib - old_contrib; +} + /* Update a sched_entity's runnable average */ static inline void update_entity_load_avg(struct sched_entity *se) { - __update_entity_runnable_avg(rq_of(cfs_rq_of(se))->clock_task, &se->avg, - se->on_rq); + struct cfs_rq *cfs_rq = cfs_rq_of(se); + long contrib_delta; + + if (!__update_entity_runnable_avg(rq_of(cfs_rq)->clock_task, &se->avg, + se->on_rq)) + return; + + contrib_delta = __update_entity_load_avg_contrib(se); + if (se->on_rq) + cfs_rq->runnable_load_avg += contrib_delta; } static inline void update_rq_runnable_avg(struct rq *rq, int runnable) { __update_entity_runnable_avg(rq->clock_task, &rq->avg, runnable); } + +/* Add the load generated by se into cfs_rq's child load-average */ +static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, + struct sched_entity *se) +{ + update_entity_load_avg(se); + cfs_rq->runnable_load_avg += se->avg.load_avg_contrib; +} + +/* Remove se's load from this cfs_rq child load-average */ +static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq, + struct sched_entity *se) +{ + update_entity_load_avg(se); + cfs_rq->runnable_load_avg -= se->avg.load_avg_contrib; +} #else static inline void update_entity_load_avg(struct sched_entity *se) {} static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {} +static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, + struct sched_entity *se) {} +static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq, + struct sched_entity *se) {} #endif static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) @@ -1223,7 +1266,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) */ update_curr(cfs_rq); update_cfs_load(cfs_rq, 0); - update_entity_load_avg(se); + enqueue_entity_load_avg(cfs_rq, se); account_entity_enqueue(cfs_rq, se); update_cfs_shares(cfs_rq); @@ -1298,7 +1341,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); - update_entity_load_avg(se); + dequeue_entity_load_avg(cfs_rq, se); update_stats_dequeue(cfs_rq, se); if (flags & DEQUEUE_SLEEP) { -- cgit v1.2.3