This is a note to let you know that I've just added the patch titled
sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sched-ensure-update_cfs_shares-is-called-for-parents-of-continuously-running-tasks.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bf0bd948d1682e3996adc093b43021ed391983e6 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Fri, 26 Jul 2013 23:48:42 +0200
Subject: sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
commit bf0bd948d1682e3996adc093b43021ed391983e6 upstream.
We typically update a task_group's shares within the dequeue/enqueue
path. However, continuously running tasks sharing a CPU are not
subject to these updates as they are only put/picked. Unfortunately,
when we reverted f269ae046 (in 17bc14b7), we lost the augmenting
periodic update that was supposed to account for this; resulting in a
potential loss of fairness.
To fix this, re-introduce the explicit update in
update_cfs_rq_blocked_load() [called via entity_tick()].
Reported-by: Max Hailperin <max@xxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Reviewed-by: Paul Turner <pjt@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-9545m3apw5d93ubyrotrj31y@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/sched/fair.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1984,6 +1984,7 @@ entity_tick(struct cfs_rq *cfs_rq, struc
*/
update_entity_load_avg(curr, 1);
update_cfs_rq_blocked_load(cfs_rq, 1);
+ update_cfs_shares(cfs_rq);
#ifdef CONFIG_SCHED_HRTICK
/*
Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are
queue-3.10/sched-ensure-update_cfs_shares-is-called-for-parents-of-continuously-running-tasks.patch
queue-3.10/perf-x86-fix-intel-qpi-uncore-event-definitions.patch
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