linux-kernel - Re: OOM detection regressions since 4.7

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: <20160823074014.GB15849@x4>
Date:   Tue, 23 Aug 2016 09:40:14 +0200
From:   Markus Trippelsdorf <markus@...ppelsdorf.de>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     Joonsoo Kim <iamjoonsoo.kim@....com>,
        Andrew Morton <akpm@...ux-foundation.org>, greg@...e.cz,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Arkadiusz Miskiewicz <a.miskiewicz@...il.com>,
        Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@...ntum.com>,
        Jiri Slaby <jslaby@...e.com>, Olaf Hering <olaf@...fle.de>,
        Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: OOM detection regressions since 4.7

On 2016.08.23 at 09:33 +0200, Michal Hocko wrote:
> On Tue 23-08-16 13:52:45, Joonsoo Kim wrote:
> [...]
> > Hello, Michal.
> > 
> > I agree with partial revert but revert should be a different form.
> > Below change try to reuse should_compact_retry() version for
> > !CONFIG_COMPACTION but it turned out that it also causes regression in
> > Markus report [1].
> 
> I would argue that CONFIG_COMPACTION=n behaves so arbitrary for high
> order workloads that calling any change in that behavior a regression
> is little bit exaggerated. Disabling compaction should have a very
> strong reason. I haven't heard any so far. I am even wondering whether
> there is a legitimate reason for that these days.

BTW, the current config description:

  CONFIG_COMPACTION:
  Allows the compaction of memory for the allocation of huge pages. 

doesn't make it clear to the user that this is an essential feature.

-- 
Markus