Re: [PATCH v2 3/4] mm/shmem, swap: improve mthp swapin process

From: Kairui Song
Date: Sun Jun 22 2025 - 23:40:34 EST


On Mon, Jun 23, 2025 at 11:37 AM Baolin Wang
<baolin.wang@xxxxxxxxxxxxxxxxx> wrote:
>
> Hi Kairui,
>
> On 2025/6/20 01:55, Kairui Song wrote:
> > From: Kairui Song <kasong@xxxxxxxxxxx>
> >
> > Tidy up the mTHP swapin code, reduce duplicated codes and slightly
> > tweak the workflow.
> >
> > For SWP_SYNCHRONOUS_IO devices, we should skip the readahead and swap
> > cache even if the swapin falls back to order 0. Readahead is not helpful
> > for such devices.
>
> Yes, agree.
>
> > Also consolidates the mTHP related check to one place so they are now
> > all wrapped by CONFIG_TRANSPARENT_HUGEPAGE, and will be trimmed off by
> > compiler if not needed.
>
> I like your idea. But I found this patch hard to review, since you you
> mixed too many changes into one patch. I think you could at least split
> it into 3 patches to make it easier for the reviewer to review and test:
>
> 1. consolidate the mTHP related check to one place (cleanup)
> 2. tidy up the mTHP swapin code (cleanup)
> 3. skip swapcache for order 0
>

Thanks for the suggestion, let me have a try, I will send a V3 later.