linux-kernel - Re: [PATCH 43/63] sched: numa: Use {cpu, pid} to create task groups for shared faults

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 07 Oct 2013 15:09:18 -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 43/63] sched: numa: Use {cpu, pid} to create task groups
 for shared faults

On 10/07/2013 06:29 AM, Mel Gorman wrote:
> From: Peter Zijlstra <peterz@...radead.org>
> 
> While parallel applications tend to align their data on the cache
> boundary, they tend not to align on the page or THP boundary.
> Consequently tasks that partition their data can still "false-share"
> pages presenting a problem for optimal NUMA placement.
> 
> This patch uses NUMA hinting faults to chain tasks together into
> numa_groups. As well as storing the NID a task was running on when
> accessing a page a truncated representation of the faulting PID is
> stored. If subsequent faults are from different PIDs it is reasonable
> to assume that those two tasks share a page and are candidates for
> being grouped together. Note that this patch makes no scheduling
> decisions based on the grouping information.
> 
> Signed-off-by: Peter Zijlstra <peterz@...radead.org>
> Signed-off-by: Mel Gorman <mgorman@...e.de>

Reviewed-by: Rik van Riel <riel@...hat.com>


-- 
All rights reversed
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/