Re: [PATCH -mm -v4 00/21] mm, THP, swap: Swapout/swapin THP in one piece

Sergey Senozhatsky
2018-07-04T02:12:02Z

On (06/27/18 21:51), Andrew Morton wrote:
> On Fri, 22 Jun 2018 11:51:30 +0800 "Huang, Ying" <ying.huang@intel.com> wrote:
>
> > This is the final step of THP (Transparent Huge Page) swap
> > optimization. After the first and second step, the splitting huge
> > page is delayed from almost the first step of swapout to after swapout
> > has been finished. In this step, we avoid splitting THP for swapout
> > and swapout/swapin the THP in one piece.
>
> It's a tremendously good performance improvement. It's also a
> tremendously large patchset :(

Will zswap gain a THP swap out/in support at some point?

mm/zswap.c: static int zswap_frontswap_store(...)
...
/* THP isn't supported */
if (PageTransHuge(page)) {
ret = -EINVAL;
goto reject;
}

-ss