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

Balbir Singh
2017-03-08T11:37:56Z

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