sched: Do not consider SCHED_IDLE tasks to be cache hot

This patch adds a check in task_hot to return if the task has SCHED_IDLE
policy. SCHED_IDLE tasks have very low weight, and when run with regular
workloads, are typically scheduled many milliseconds apart. There is no
need to consider these tasks hot for load balancing.

Signed-off-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1287173550-30365-2-git-send-email-ncrao@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Nikhil Rao 2010-10-13 12:09:35 -07:00 committed by Ingo Molnar
parent 17bdcf949d
commit ef8002f684

View File

@ -2025,6 +2025,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
if (p->sched_class != &fair_sched_class) if (p->sched_class != &fair_sched_class)
return 0; return 0;
if (unlikely(p->policy == SCHED_IDLE))
return 0;
/* /*
* Buddy candidates are cache hot: * Buddy candidates are cache hot:
*/ */