---
Subject: sched: adjust timer_slack_ns on scheduler policy change
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Date: Thu Mar 12 15:01:02 CET 2009
Ensure RT tasks have 0 timer slack.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
kernel/sched.c | 2 ++
1 file changed, 2 insertions(+)
Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -5511,10 +5511,12 @@ __setscheduler(struct rq *rq, struct tas
case SCHED_NORMAL:
case SCHED_BATCH:
case SCHED_IDLE:
+ p->timer_slack_ns = p->default_timer_slack_ns;
p->sched_class = &fair_sched_class;
break;
case SCHED_FIFO:
case SCHED_RR:
+ p->timer_slack_ns = 0;
p->sched_class = &rt_sched_class;
break;
}
Looking at the default_timer_slack_ns stuff, do we want something like
the below?