Re: [PATCH 4/5] mm: zswap: add basic meminfo and vmstat coverage

Suleiman Souhlal
2022-05-05T22:24:51Z

On Fri, May 6, 2022 at 4:33 AM Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrote:
>
> On Thu, Apr 28, 2022 at 9:54 AM Yang Shi <shy828301-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> >
> [...]
> > > Yes, we have some modifications to zswap to make it work without any
> > > backing real swap. Though there is a future plan to move to zram
> > > eventually.
> >
> > Interesting, if so why not just simply use zram?
> >
>
> Historical reasons. When we started trying out the zswap, I think zram
> was still in staging or not stable enough (Suleiman can give a better
> answer).

One of the reasons we chose zswap instead of zram is that zswap can
reject pages.
Also, we wanted to have per-memcg pools, which zswap made much easier to do.

-- Suleiman