Re: [PATCH -mm -v7 0/9] THP swap: Delay splitting THP during swapping out

From: Andrew Morton
Date: Tue Mar 28 2017 - 18:14:34 EST


On Tue, 28 Mar 2017 13:32:00 +0800 "Huang, Ying" <ying.huang@xxxxxxxxx> wrote:

> Hi, Andrew, could you help me to check whether the overall design is
> reasonable?
>
> Hi, Hugh, Shaohua, Minchan and Rik, could you help me to review the
> swap part of the patchset? Especially [1/9], [3/9], [4/9], [5/9],
> [6/9], [9/9].
>
> Hi, Andrea could you help me to review the THP part of the patchset?
> Especially [2/9], [7/9] and [8/9].
>
> Hi, Johannes, Michal and Vladimir, I am not very confident about the
> memory cgroup part, especially [2/9]. Could you help me to review it?
>
> And for all, Any comment is welcome!
>
>
> Recently, the performance of the storage devices improved so fast that
> we cannot saturate the disk bandwidth with single logical CPU when do
> page swap out even on a high-end server machine. Because the
> performance of the storage device improved faster than that of single
> logical CPU. And it seems that the trend will not change in the near
> future. On the other hand, the THP becomes more and more popular
> because of increased memory size. So it becomes necessary to optimize
> THP swap performance.

I'll merge this patchset for testing purposes, but I don't believe that
it has yet had sufficient review. And thanks for drawing our attention
to those parts where you believe close review is needed - that helps.