Arjan van de Ven wrote:
Peter Zijlstra wrote:--- 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?the original idea was that you had a default slack that you got from exec time,and then something you could just tweak around yourself independently.... this would throw that out of the window.
It seems to me that changing your scheduling class from userspace would be reasonable justification to change the timer slack to a default value for that class. Thoughts?
-- Darren Hart IBM Linux Technology Center Real-Time Linux Team -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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