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 <[email protected]> know about it.


>From bf0bd948d1682e3996adc093b43021ed391983e6 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <[email protected]>
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 <[email protected]>

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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Reviewed-by: Paul Turner <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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 [email protected] 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
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to