From 5d2b3d3695a841231b65b5536a70dc29961c5611 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 12 Aug 2007 18:08:19 +0200 Subject: sched: fix sleeper bonus Peter Ziljstra noticed that the sleeper bonus deduction code was not properly rate-limited: a task that scheduled more frequently would get a disproportionately large deduction. So limit the deduction to delta_exec. Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index c5af38948a1..fedbb51bba9 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -75,7 +75,7 @@ enum { unsigned int sysctl_sched_features __read_mostly = SCHED_FEAT_FAIR_SLEEPERS *1 | - SCHED_FEAT_SLEEPER_AVG *1 | + SCHED_FEAT_SLEEPER_AVG *0 | SCHED_FEAT_SLEEPER_LOAD_AVG *1 | SCHED_FEAT_PRECISE_CPU_LOAD *1 | SCHED_FEAT_START_DEBIT *1 | @@ -304,11 +304,9 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr) delta_mine = calc_delta_mine(delta_exec, curr->load.weight, lw); if (cfs_rq->sleeper_bonus > sysctl_sched_granularity) { - delta = calc_delta_mine(cfs_rq->sleeper_bonus, - curr->load.weight, lw); - if (unlikely(delta > cfs_rq->sleeper_bonus)) - delta = cfs_rq->sleeper_bonus; - + delta = min(cfs_rq->sleeper_bonus, (u64)delta_exec); + delta = calc_delta_mine(delta, curr->load.weight, lw); + delta = min((u64)delta, cfs_rq->sleeper_bonus); cfs_rq->sleeper_bonus -= delta; delta_mine -= delta; } @@ -521,6 +519,8 @@ static void __enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) * Track the amount of bonus we've given to sleepers: */ cfs_rq->sleeper_bonus += delta_fair; + if (unlikely(cfs_rq->sleeper_bonus > sysctl_sched_runtime_limit)) + cfs_rq->sleeper_bonus = sysctl_sched_runtime_limit; schedstat_add(cfs_rq, wait_runtime, se->wait_runtime); } -- cgit v1.2.3-70-g09d2