Re: [PATCH 1/2] MM: handle THP in swap_*page_fs()

From: Andrew Morton
Date: Thu Apr 28 2022 - 21:21:44 EST


On Fri, 29 Apr 2022 10:43:34 +1000 NeilBrown <neilb@xxxxxxx> wrote:

> Pages passed to swap_readpage()/swap_writepage() are not necessarily all
> the same size - there may be transparent-huge-pages involves.
>
> The BIO paths of swap_*page() handle this correctly, but the SWP_FS_OPS
> path does not.
>
> So we need to use thp_size() to find the size, not just assume
> PAGE_SIZE, and we need to track the total length of the request, not
> just assume it is "page * PAGE_SIZE".

Cool. I added this in the series after
mm-submit-multipage-write-for-swp_fs_ops-swap-space.patch. I could
later squash it into that patch if you think that's more logical.