[tip:sched/urgent] sched: Fix volanomark performance regression

From: tip-bot for Alex Shi
Date: Thu Nov 18 2010 - 09:09:25 EST


Commit-ID: b5482cfa1c95a188b3054fa33274806add91bbe5
Gitweb: http://git.kernel.org/tip/b5482cfa1c95a188b3054fa33274806add91bbe5
Author: Alex Shi <alex.shi@xxxxxxxxx>
AuthorDate: Tue, 16 Nov 2010 17:34:02 +0800
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 18 Nov 2010 13:11:43 +0100

sched: Fix volanomark performance regression

Commit fab4762 triggers excessive idle balancing, causing a ~30% loss in
volanomark throughput. Remove idle balancing throttle reset.

Originally-by: Alex Shi <alex.shi@xxxxxxxxx>
Signed-off-by: Mike Galbraith <efault@xxxxxx>
Acked-by: Nikhil Rao <ncrao@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <1289928732.5169.211.camel@xxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/sched_fair.c | 4 ----
1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 52ab113..ba0556d 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1758,10 +1758,6 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
set_task_cpu(p, this_cpu);
activate_task(this_rq, p, 0);
check_preempt_curr(this_rq, p, 0);
-
- /* re-arm NEWIDLE balancing when moving tasks */
- src_rq->avg_idle = this_rq->avg_idle = 2*sysctl_sched_migration_cost;
- this_rq->idle_stamp = 0;
}

/*
--
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