| Date | Tue, 15 Feb 2011 17:46:00 -0800 | From | Greg KH <> | Subject | [094/115] sched: Do not consider SCHED_IDLE tasks to be cache hot |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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Commit: ef8002f6848236de5adc613063ebeabddea8a6fb upstream
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> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- kernel/sched.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/kernel/sched.c +++ b/kernel/sched.c @@ -2014,6 +2014,9 @@ task_hot(struct task_struct *p, u64 now, if (p->sched_class != &fair_sched_class) return 0; + if (unlikely(p->policy == SCHED_IDLE)) + return 0; + /* * Buddy candidates are cache hot: */
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