Commit ef9884e6 authored Jan 31, 2008 by Peter Zijlstra Committed by Ingo Molnar Jan 31, 2008

sched: let +nice tasks have smaller impact



Michel Dänzr has bisected an interactivity problem with
plus-reniced tasks back to this commit:

 810e95cc is first bad commit
 commit 810e95cc
 Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
 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 <michel@tungstengraphics.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 296825cb

kernel/sched_fair.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -1106,7 +1106,11 @@ 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)