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Date: Wed, 25 Jul 2012 22:16:34 +0400
From: Glauber Costa <glommer@parallels.com>
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To: Christoph Lameter <cl@linux.com>
CC: <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        David Rientjes <rientjes@google.com>,
        Pekka Enberg <penberg@kernel.org>, Greg Thelen <gthelen@google.com>,
        Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.cz>,
        Frederic Weisbecker <fweisbec@gmail.com>, <devel@openvz.org>,
        <cgroups@vger.kernel.org>, Pekka Enberg <penberg@cs.helsinki.fi>,
        Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        Suleiman Souhlal <suleiman@google.com>
Subject: Re: [PATCH 10/10] memcg/sl[au]b: shrink dead caches
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On 07/25/2012 09:13 PM, Christoph Lameter wrote:
> On Wed, 25 Jul 2012, Glauber Costa wrote:
> 
>> In the slub allocator, when the last object of a page goes away, we
>> don't necessarily free it - there is not necessarily a test for empty
>> page in any slab_free path.
> 
> That is true for the slab allocator as well. In either case calling
> kmem_cache_shrink() will make the objects go away by draining the cached
> objects and freeing the pages used for the objects back to the page
> allocator. You do not need this patch. Just call the proper functions to
> drop the objecgts in the caches in either allocator.
> 
>> The slab allocator has a time based reaper that would eventually get rid
>> of the objects, but we can also call it explicitly, since dead caches
>> are not a likely event.
> 
> So this is already for both allocators?
> 
Yes, I just didn't updated the whole changelog. my bad.