linux-kernel - Re: [PATCH v2 04/11] kmem accounting basic infrastructure

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:	Wed, 15 Aug 2012 15:34:39 +0000
From:	Christoph Lameter <cl@...ux.com>
To:	Glauber Costa <glommer@...allels.com>
cc:	Michal Hocko <mhocko@...e.cz>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, cgroups@...r.kernel.org, devel@...nvz.org,
	Johannes Weiner <hannes@...xchg.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	kamezawa.hiroyu@...fujitsu.com,
	David Rientjes <rientjes@...gle.com>,
	Pekka Enberg <penberg@...nel.org>
Subject: Re: [PATCH v2 04/11] kmem accounting basic infrastructure

On Wed, 15 Aug 2012, Glauber Costa wrote:

> On 08/15/2012 06:47 PM, Christoph Lameter wrote:
> > On Wed, 15 Aug 2012, Michal Hocko wrote:
> >
> >>> That is not what the kernel does, in general. We assume that if he wants
> >>> that memory and we can serve it, we should. Also, not all kernel memory
> >>> is unreclaimable. We can shrink the slabs, for instance. Ying Han
> >>> claims she has patches for that already...
> >>
> >> Are those patches somewhere around?
> >
> > You can already shrink the reclaimable slabs (dentries / inodes) via
> > calls to the subsystem specific shrinkers. Did Ying Han do anything to
> > go beyond that?
> >
> That is not enough for us.
> We would like to make sure that the objects being discarded belong to
> the memcg which is under pressure. We don't need to be perfect here, and
> an occasional slip is totally fine. But if in general, shrinking from
> memcg A will mostly wipe out objects from memcg B, we harmed the system
> in return for nothing good.

How can you figure out which objects belong to which memcg? The ownerships
of dentries and inodes is a dubious concept already.

--
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/