linux-kernel - Re: [PATCH] mm: add config option to select the initial overcommit mode

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: <20160513145445.GT20141@dhcp22.suse.cz>
Date:	Fri, 13 May 2016 16:54:45 +0200
From:	Michal Hocko <mhocko@...nel.org>
To:	Sebastian Frias <sf84@...oste.net>
Cc:	"Austin S. Hemmelgarn" <ahferroin7@...il.com>,
	Mason <slash.tmp@...e.fr>, linux-mm@...ck.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mm: add config option to select the initial overcommit
 mode

On Fri 13-05-16 16:35:20, Sebastian Frias wrote:
> Hi Austin,
> 
> On 05/13/2016 03:51 PM, Austin S. Hemmelgarn wrote:
> > On 2016-05-13 09:32, Sebastian Frias wrote:
> >> I didn't see that in Documentation/vm/overcommit-accounting or am I looking in the wrong place?
> > It's controlled by a sysctl value, so it's listed in Documentation/sysctl/vm.txt
> > The relevant sysctl is vm.oom_kill_allocating_task
> 
> Thanks, I just read that.
> Does not look like a replacement for overcommit=never though.

No this is just an OOM strategy. I wouldn't recommend it though because
the behavior might be really time dependant - unlike the regular OOM
killer strategy to select the largest memory consumer.

And again, overcommit=never doesn't imply no-OOM. It just makes it less
likely. The kernel can consume quite some unreclaimable memory as well.
-- 
Michal Hocko
SUSE Labs