Date: Fri, 11 May 2012 14:09:15 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
To: Glauber Costa <glommer@parallels.com>
cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org,
        kamezawa.hiroyu@jp.fujitsu.com, Tejun Heo <tj@kernel.org>,
        Li Zefan <lizefan@huawei.com>, Greg Thelen <gthelen@google.com>,
        Suleiman Souhlal <suleiman@google.com>, Michal Hocko <mhocko@suse.cz>,
        Johannes Weiner <hannes@cmpxchg.org>, devel@openvz.org,
        Pekka Enberg <penberg@cs.helsinki.fi>
Subject: Re: [PATCH v2 04/29] slub: always get the cache from its page in
 kfree
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On Fri, 11 May 2012, Glauber Costa wrote:

> On 05/11/2012 03:56 PM, Christoph Lameter wrote:
> > On Fri, 11 May 2012, Glauber Costa wrote:
> >
> > > So we don't mix pages from multiple memcgs in the same cache - we believe
> > > that
> > > would be too confusing.
> >
> > Well subsystem create caches and other things that are shared between
> > multiple processes. How can you track that?
>
> Each process that belongs to a memcg triggers the creation of a new child kmem
> cache.

I see that. But there are other subsystems from slab allocators that do
the same. There are also objects that may be used by multiple processes.
F.e what about shm?

> > > /proc/slabinfo reflects this information, by listing the memcg-specific
> > > slabs.
> >
> > What about /sys/kernel/slab/*?
>
> From the PoV of the global system, what you'll see is something like:
> dentry , dentry(2:memcg1), dentry(2:memcg2), etc.

Hmmm.. Would be better to have a hierachy there. /proc/slabinfo is more
legacy.
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