linux-kernel - Re: [PATCH 27/34] mm, vmscan: Have kswapd reclaim from all zones if reclaiming and buffer_heads_over

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: <20160712181048.GC7821@cmpxchg.org>
Date:	Tue, 12 Jul 2016 14:10:48 -0400
From:	Johannes Weiner <hannes@...xchg.org>
To:	Mel Gorman <mgorman@...hsingularity.net>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Linux-MM <linux-mm@...ck.org>, Rik van Riel <riel@...riel.com>,
	Vlastimil Babka <vbabka@...e.cz>,
	Minchan Kim <minchan@...nel.org>,
	Joonsoo Kim <iamjoonsoo.kim@....com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 27/34] mm, vmscan: Have kswapd reclaim from all zones if
 reclaiming and buffer_heads_over_limit

On Fri, Jul 08, 2016 at 10:35:03AM +0100, Mel Gorman wrote:
> The buffer_heads_over_limit limit in kswapd is inconsistent with direct
> reclaim behaviour. It may force an an attempt to reclaim from all zones and
> then not reclaim at all because higher zones were balanced than required
> by the original request.
> 
> This patch will causes kswapd to consider reclaiming from all zones if
> buffer_heads_over_limit.  However, if there are eligible zones for the
> allocation request that woke kswapd then no reclaim will occur even if
> buffer_heads_over_limit. This avoids kswapd over-reclaiming just because
> buffer_heads_over_limit.
> 
> Signed-off-by: Mel Gorman <mgorman@...hsingularity.net>

Acked-by: Johannes Weiner <hannes@...xchg.org>