linux-kernel - Re: [PATCH 07/11] mm: page allocator: Do not call direct reclaim for THP allocations while compaction is deferred

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]

Message-ID: <4EEAC4AC.90600@redhat.com>
Date:	Thu, 15 Dec 2011 23:10:20 -0500
From:	Rik van Riel <riel@...hat.com>
To:	Mel Gorman <mgorman@...e.de>
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Minchan Kim <minchan.kim@...il.com>,
	Dave Jones <davej@...hat.com>, Jan Kara <jack@...e.cz>,
	Andy Isaacson <adi@...apodia.org>,
	Johannes Weiner <jweiner@...hat.com>,
	Nai Xia <nai.xia@...il.com>, Linux-MM <linux-mm@...ck.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 07/11] mm: page allocator: Do not call direct reclaim
 for THP allocations while compaction is deferred

On 12/14/2011 10:41 AM, Mel Gorman wrote:
> If compaction is deferred, direct reclaim is used to try free enough
> pages for the allocation to succeed. For small high-orders, this has
> a reasonable chance of success. However, if the caller has specified
> __GFP_NO_KSWAPD to limit the disruption to the system, it makes more
> sense to fail the allocation rather than stall the caller in direct
> reclaim. This patch skips direct reclaim if compaction is deferred
> and the caller specifies __GFP_NO_KSWAPD.
>
> Async compaction only considers a subset of pages so it is possible for
> compaction to be deferred prematurely and not enter direct reclaim even
> in cases where it should. To compensate for this, this patch also defers
> compaction only if sync compaction failed.
>
> Signed-off-by: Mel Gorman<mgorman@...e.de>
> Acked-by: Minchan Kim<minchan.kim@...il.com>

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/