Date: Tue, 10 Nov 2015 13:38:08 -0500
From: Tejun Heo <tj@kernel.org>
To: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@kernel.org>,
        Greg Thelen <gthelen@google.com>, Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, linux-mm@kvack.org,
        cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/6] slab: add SLAB_ACCOUNT flag
Message-ID: <20151110183808.GB13740@mtj.duckdns.org>
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On Tue, Nov 10, 2015 at 09:34:05PM +0300, Vladimir Davydov wrote:
> Currently, if we want to account all objects of a particular kmem cache,
> we have to pass __GFP_ACCOUNT to each kmem_cache_alloc call, which is
> inconvenient. This patch introduces SLAB_ACCOUNT flag which if passed to
> kmem_cache_create will force accounting for every allocation from this
> cache even if __GFP_ACCOUNT is not passed.
> 
> This patch does not make any of the existing caches use this flag - it
> will be done later in the series.
> 
> Note, a cache with SLAB_ACCOUNT cannot be merged with a cache w/o
> SLAB_ACCOUNT, i.e. using this flag will probably reduce the number of
> merged slabs even if kmem accounting is not used (only compiled in).

Am I correct in thinking that we should eventually be able to removed
__GFP_ACCOUNT and that only caches explicitly marked with SLAB_ACCOUNT
would need to be handled by kmemcg?

Thanks a lot for doing this!

-- 
tejun
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