Re: [RFC PATCH 0/5] mm: support zswap-backed anonymous large folio swapin

[Yosry Ahmed]

> >> Feedback would be especially helpful on:
> >>
> >> 1. whether it makes sense to support all-zswap large folio swapin first,
> >>    while keeping mixed zswap/disk ranges on the order-0 fallback path
> >
> > I think so, yes, but based on my read of the code this RFC only affects
> > synchornous swapin, which is more-or-less zram+zswap. This is an
> > uncommon setup outside of testing.
>
> BLK_FEAT_SYNCHRONOUS is also set for pmem and brd devices I think, but that's
> also pretty uncommon I assume. Well, maybe if your hypervisor provides you with
> an emulated NVDIMM to use as swap backend ... maybe.

Yeah, I said "more-or-less" to capture pmem/brd/etc :P

> I thought there were other ways to get BLK_FEAT_SYNCHRONOUS set, but I don't see
> other usage.
>
> So seeing it for zswap is pretty rare I assume.

Yeah that's my understanding as well.