On Thu, May 5, 2022 at 3:25 PM Suleiman Souhlal <suleiman@xxxxxxxxxx> wrote: > > On Fri, May 6, 2022 at 4:33 AM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote: > > > > On Thu, Apr 28, 2022 at 9:54 AM Yang Shi <shy828301@xxxxxxxxx> 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. Yes, it was a design choice. zswap was cache-like (tiering) and zram was storage-like (endpoint). Though nowadays the distinction is blurry. It had nothing to do with zram being in staging -- when we took zswap, it was out of the tree.
