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Date: Tue, 23 Sep 2014 11:31:11 +0400
From: Vladimir Davydov <vdavydov@parallels.com>
To: Johannes Weiner <hannes@cmpxchg.org>
CC: Andrew Morton <akpm@linux-foundation.org>, <linux-kernel@vger.kernel.org>,
        <linux-mm@kvack.org>, Michal Hocko <mhocko@suse.cz>,
        Christoph Lameter <cl@linux.com>
Subject: Re: [PATCH 1/2] memcg: move memcg_{alloc,free}_cache_params to
 slab_common.c
Message-ID: <20140923073111.GC3588@esperanza>
References: <e768785511927d65bd3e6d9f65ab2a9851a3d73d.1411054735.git.vdavydov@parallels.com>
 <20140922200825.GA5373@cmpxchg.org>
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On Mon, Sep 22, 2014 at 04:08:25PM -0400, Johannes Weiner wrote:
> On Thu, Sep 18, 2014 at 07:50:19PM +0400, Vladimir Davydov wrote:
> > The only reason why they live in memcontrol.c is that we get/put css
> > reference to the owner memory cgroup in them. However, we can do that in
> > memcg_{un,}register_cache.
> > 
> > So let's move them to slab_common.c and make them static.
> > 
> > Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
> > Cc: Johannes Weiner <hannes@cmpxchg.org>
> > Cc: Michal Hocko <mhocko@suse.cz>
> > Cc: Christoph Lameter <cl@linux.com>
> 
> Cool, so you get rid of the back-and-forth between memcg and slab, and
> thereby also shrink the public memcg interface.

It should be mentioned that we still call memcg_update_array_size()
(defined at memcontrol.c) from memcg_update_all_caches()
(slab_common.c), because we must hold the slab_mutex while updating
memcg_limited_groups_array_size. However, I'm going to remove this
requirement and get rid of memcg_update_array_size() too. This is what
"[PATCH -mm 10/14] memcg: add rwsem to sync against memcg_caches arrays
relocation", which is a part of my "Per memcg slab shrinkers" patch set,
does.

Thanks,
Vladimir