From 818b7bc903fc96665eb6c885b1180e3268756d33 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 31 Jan 2008 22:45:22 +0100 Subject: sched: let +nice tasks have smaller impact MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit patch ef9884e6f29bbe1075204f962a00f7533bf7e8f3 in mainline. Michel Dänzr has bisected an interactivity problem with plus-reniced tasks back to this commit: 810e95ccd58d91369191aa4ecc9e6d4a10d8d0c8 is first bad commit commit 810e95ccd58d91369191aa4ecc9e6d4a10d8d0c8 Author: Peter Zijlstra Date: Mon Oct 15 17:00:14 2007 +0200 sched: another wakeup_granularity fix unit mis-match: wakeup_gran was used against a vruntime fix this by assymetrically scaling the vtime of positive reniced tasks. Bisected-by: Michel Dänzer Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/sched_fair.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index da7c061e720..94e88beb15f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -867,7 +867,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) } gran = sysctl_sched_wakeup_granularity; - if (unlikely(se->load.weight != NICE_0_LOAD)) + /* + * More easily preempt - nice tasks, while not making + * it harder for + nice tasks. + */ + if (unlikely(se->load.weight > NICE_0_LOAD)) gran = calc_delta_fair(gran, &se->load); if (pse->vruntime + gran < se->vruntime) -- cgit v1.2.3-18-g5258