Re: [RFC PATCH] mm: z3fold: rename CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED

[Yosry Ahmed <yosryahmed@google.com>]

On Sun, Jan 21, 2024 at 11:42 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Tue, Jan 16, 2024 at 12:19:39PM -0800, Yosry Ahmed wrote:
> > Well, better compression ratios for one :)
> >
> > I think a long time ago there were complaints that zsmalloc had higher
> > latency than zbud/z3fold, but since then a lot of things have changed
> > (including nice compaction optimization from Sergey, and compaction
> > was one of the main factors AFAICT). Also, recent experiments that
> > Chris Li conducted showed that (at least in our setup), the
> > decompression is only a small part of the fault latency with zswap
> > (i.e. not the main factor) -- so I am not sure if it actually matters
> > in practice.
> >
> > That said, I have not conducted any experiments personally with z3fold
> > or zbud, which is why I proposed the conservative approach of marking
> > as deprecated first. However, if others believe this is unnecessary I
> > am fine with removal as well. Whatever we agree on is fine by me.
>
> In general deprecated is for code that has active (intentional) users
> and/or would break setups.  I does sound to me like that is not the
> case here, but others might understand this better.

I generally agree. So far we have no knowledge of active users, and if
there are some, I expect most of them to be able to switch to zsmalloc
with no problems. That being said, I was trying to take the
conservative approach. If others agree I can send a removal patch
instead.