Re: [PATCH -mm -v6 2/9] mm, memcg: Support to charge/uncharge multiple swap entries

[Balbir Singh]

On Wed, 2017-03-08 at 15:26 +0800, Huang, Ying wrote:
> From: Huang Ying <ying.huang@xxxxxxxxx>
>Â
> This patch make it possible to charge or uncharge a set of continuous
> swap entries in the swap cgroup.ÂÂThe number of swap entries is
> specified via an added parameter.
>Â
> 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.ÂÂSo a set of (HPAGE_PMD_NR) continuous swap entries backing one
> THP need to be charged or uncharged together.ÂÂThis 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