From b77d69db9f4ba03b2ed17e383c2d73ca89f5ab14 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 28 Aug 2007 12:53:24 +0200 Subject: sched: fix wait_start_fair condition in update_stats_wait_end() Peter Zijlstra noticed the following bug in SCHED_FEAT_SKIP_INITIAL (which is disabled by default at the moment): it relies on se.wait_start_fair being 0 while update_stats_wait_end() did not recognize a 0 value, so instead of 'skipping' the initial interval we gave the new child a maximum boost of +runtime-limit ... (No impact on the default kernel, but nice to fix for completeness.) Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra Signed-off-by: Mike Galbraith --- kernel/sched_fair.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 9f06094e5275..0c718857176f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -489,6 +489,9 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) { unsigned long delta_fair; + if (unlikely(!se->wait_start_fair)) + return; + delta_fair = (unsigned long)min((u64)(2*sysctl_sched_runtime_limit), (u64)(cfs_rq->fair_clock - se->wait_start_fair)); -- cgit v1.2.2