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Message-ID: <1488973076.13674.5.camel@gmail.com>
Subject: Re: [PATCH -mm -v6 2/9] mm, memcg: Support to charge/uncharge
 multiple swap entries
From: Balbir Singh <bsingharora@gmail.com>
To: "Huang, Ying" <ying.huang@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrea Arcangeli <aarcange@redhat.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Vladimir Davydov <vdavydov@virtuozzo.com>,
        Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@kernel.org>,
        Tejun Heo <tj@kernel.org>, cgroups@vger.kernel.org
Date: Wed, 08 Mar 2017 22:37:56 +1100
In-Reply-To: <20170308072613.17634-3-ying.huang@intel.com>
References: <20170308072613.17634-1-ying.huang@intel.com>
         <20170308072613.17634-3-ying.huang@intel.com>
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On Wed, 2017-03-08 at 15:26 +0800, Huang, Ying wrote:
> From: Huang Ying <ying.huang@intel.com>
> 
> This patch make it possible to charge or uncharge a set of continuous
> swap entries in the swap cgroup.  The number of swap entries is
> specified via an added parameter.
> 
> This will be used for the THP (Transparent Huge Page) swap support.
> Where a swap cluster backing a THP may be allocated and freed as a
> whole.  So a set of (HPAGE_PMD_NR) continuous swap entries backing one
> THP need to be charged or uncharged together.  This will batch the
> cgroup operations for the THP swap too.

A quick look at the patches makes it look sane. I wonder if we would
make sense to track THP swapout separately as well
(from a memory.stat perspective)

Balbir Singh