From d6b5591829bd348a5fbe1c428d28dea00621cdba Mon Sep 17 00:00:00 2001 From: Paul Turner Date: Mon, 15 Nov 2010 15:47:09 -0800 Subject: sched: Allow update_cfs_load() to update global load Refactor the global load updates from update_shares_cpu() so that update_cfs_load() can update global load when it is more than ~10% out of sync. The new global_load parameter allows us to force an update, regardless of the error factor so that we can synchronize w/ update_shares(). Signed-off-by: Paul Turner Signed-off-by: Peter Zijlstra LKML-Reference: <20101115234938.377473595@google.com> Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 44 +++++++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 15 deletions(-) (limited to 'kernel/sched_fair.c') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index e7e2f08e6d01..390ce30ff2d0 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -539,7 +539,7 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) return calc_delta_fair(sched_slice(cfs_rq, se), se); } -static void update_cfs_load(struct cfs_rq *cfs_rq); +static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update); static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta); /* @@ -565,7 +565,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr, #ifdef CONFIG_FAIR_GROUP_SCHED cfs_rq->load_unacc_exec_time += delta_exec; if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) { - update_cfs_load(cfs_rq); + update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq, 0); } #endif @@ -704,7 +704,22 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) } #if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED -static void update_cfs_load(struct cfs_rq *cfs_rq) +static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq, + int global_update) +{ + struct task_group *tg = cfs_rq->tg; + long load_avg; + + load_avg = div64_u64(cfs_rq->load_avg, cfs_rq->load_period+1); + load_avg -= cfs_rq->load_contribution; + + if (global_update || abs(load_avg) > cfs_rq->load_contribution / 8) { + atomic_add(load_avg, &tg->load_weight); + cfs_rq->load_contribution += load_avg; + } +} + +static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update) { u64 period = sysctl_sched_shares_window; u64 now, delta; @@ -731,6 +746,11 @@ static void update_cfs_load(struct cfs_rq *cfs_rq) cfs_rq->load_avg += delta * load; } + /* consider updating load contribution on each fold or truncate */ + if (global_update || cfs_rq->load_period > period + || !cfs_rq->load_period) + update_cfs_rq_load_contribution(cfs_rq, global_update); + while (cfs_rq->load_period > period) { /* * Inline assembly required to prevent the compiler @@ -790,7 +810,7 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta) reweight_entity(cfs_rq_of(se), se, shares); } #else /* CONFIG_FAIR_GROUP_SCHED */ -static inline void update_cfs_load(struct cfs_rq *cfs_rq) +static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update) { } @@ -920,7 +940,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); - update_cfs_load(cfs_rq); + update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq, se->load.weight); account_entity_enqueue(cfs_rq, se); @@ -981,7 +1001,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) if (se != cfs_rq->curr) __dequeue_entity(cfs_rq, se); se->on_rq = 0; - update_cfs_load(cfs_rq); + update_cfs_load(cfs_rq, 0); account_entity_dequeue(cfs_rq, se); update_min_vruntime(cfs_rq); update_cfs_shares(cfs_rq, 0); @@ -1216,7 +1236,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); - update_cfs_load(cfs_rq); + update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq, 0); } @@ -1246,7 +1266,7 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) for_each_sched_entity(se) { struct cfs_rq *cfs_rq = cfs_rq_of(se); - update_cfs_load(cfs_rq); + update_cfs_load(cfs_rq, 0); update_cfs_shares(cfs_rq, 0); } @@ -2052,7 +2072,6 @@ static int update_shares_cpu(struct task_group *tg, int cpu) struct cfs_rq *cfs_rq; unsigned long flags; struct rq *rq; - long load_avg; if (!tg->se[cpu]) return 0; @@ -2063,12 +2082,7 @@ static int update_shares_cpu(struct task_group *tg, int cpu) raw_spin_lock_irqsave(&rq->lock, flags); update_rq_clock(rq); - update_cfs_load(cfs_rq); - - load_avg = div64_u64(cfs_rq->load_avg, cfs_rq->load_period+1); - load_avg -= cfs_rq->load_contribution; - atomic_add(load_avg, &tg->load_weight); - cfs_rq->load_contribution += load_avg; + update_cfs_load(cfs_rq, 1); /* * We need to update shares after updating tg->load_weight in -- cgit v1.2.3-70-g09d2