linux-kernel - Re: [PATCH 0/50] Basic scheduler support for automatic NUMA balancing V7

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Date:	Tue, 10 Sep 2013 22:03:46 -0400
From:	Rik van Riel <riel@...hat.com>
To:	Mel Gorman <mgorman@...e.de>
CC:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...nel.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>,
	Linux-MM <linux-mm@...ck.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/50] Basic scheduler support for automatic NUMA balancing
 V7

On 09/10/2013 05:31 AM, Mel Gorman wrote:
> It has been a long time since V6 of this series and time for an update. Much
> of this is now stabilised with the most important addition being the inclusion
> of Peter and Rik's work on grouping tasks that share pages together.
> 
> This series has a number of goals. It reduces overhead of automatic balancing
> through scan rate reduction and the avoidance of TLB flushes. It selects a
> preferred node and moves tasks towards their memory as well as moving memory
> toward their task. It handles shared pages and groups related tasks together.

The attached two patches should fix the task grouping issues
we discussed on #mm earlier.

Now on to the load balancer. When specjbb takes up way fewer
CPUs than what are available on a node, it is possible for
multiple specjbb processes to end up on the same NUMA node,
and the load balancer makes no attempt to move some of them
to completely idle loads.

I have not figured out yet how to fix that behaviour...

-- 
All rights reversed

View attachment "0061-exec-leave-numa-group.patch" of type "text/x-patch" (2246 bytes)

View attachment "0062-numa-join-group-carefully.patch" of type "text/x-patch" (6168 bytes)