Re: [PATCH 00/15] add zpdesc memory descriptor for zswap.zpool

Yosry Ahmed
2024-06-25T10:31:22Z

On Tue, Jun 25, 2024 at 1:11 AM Alex Shi <seakeel@gmail.com> wrote:
>
>
>
> On 6/25/24 5:46 AM, Yosry Ahmed wrote:
> > On Thu, Jun 20, 2024 at 10:42 PM <alexs@kernel.org> wrote:
> >>
> >> From: Alex Shi <alexs@kernel.org>
> >>
> >> According to Metthew's plan, the page descriptor will be replace by a 8
> >> bytes mem_desc on destination purpose.
> >> https://lore.kernel.org/lkml/YvV1KTyzZ+Jrtj9x@casper.infradead.org/
> >>
> >> Here is a implement on z3fold to replace page descriptor by zpdesc,
> >> which is still overlay on struct page now. but it's a step move forward
> >> above destination.
> >>
> >> To name the struct zpdesc instead of z3fold_desc, since there are 3 zpool
> >> usages under zswap, zbud, z3fold, zsmalloc. It looks like we may extend the
> >> zpdesc to zbud and zsmalloc, combined their usage into one.
> >
> > Please do not focus your development efforts on z3fold. We really want
> > to deprecate/remove it, as well as zbud eventually. See [1].
> >
> > For zsmalloc, there is already an ongoing effort to split zsdesc from
> > struct page [2].
> >
> > [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndqF+3+_Vg@mail.gmail.com/
>
> Hi Yosry,
>
> Thanks a lot for the info and comments! It's my stupid w/o checking the email list before work on it.
> Anyway don't know if z3fold would be removed, jut left this tested patchset here if someone need it.

It's partially our fault for leaving z3fold knowing that it is headed
toward deprecation/removal. FWIW, I tried to remove it or mark it as
deprecated, but there was some resistance :/