This is a note to let you know that I've just added the patch titled
sched: Do not consider SCHED_IDLE tasks to be cache hot
to the 2.6.32-longterm tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary
The filename of the patch is:
0009-sched-Do-not-consider-SCHED_IDLE-tasks-to-be-cache-h.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the 2.6.32 longterm
tree,
please let <[email protected]> know about it.
>From 9c47bab95bb2c15fe88da9ab8da878105a7e1db5 Mon Sep 17 00:00:00 2001
From: Nikhil Rao <[email protected]>
Date: Thu, 10 Feb 2011 10:23:25 +0100
Subject: sched: Do not consider SCHED_IDLE tasks to be cache hot
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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Mike Galbraith <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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:
*/
Patches currently in longterm-queue-2.6.32 which might be from [email protected]
are
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