Re: [PATCH] mm/memcontrol: respect zswap.writeback setting from parent cg too

[Yosry Ahmed <yosryahmed@google.com>]

On Mon, Aug 19, 2024 at 6:01 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Mon, 19 Aug 2024 12:05:44 -0700 Yosry Ahmed <yosryahmed@google.com> wrote:
>
> > > Ah yeah, I was thinking this could be done in a follow-up patch.
> > >
> > > But yes, please - documentation. Preferably everything together as v2.
> > >
> > > >
> > > > Also, do we want a Fixes tag and to backport this so that current
> > > > users get the new behavior ASAP?
> > >
> > > Hmm, I wonder if it's more confusing for users to change the behavior
> > > in older kernels.
> > >
> > > (OTOH, if this already is what people expect, then yeah it's a good
> > > idea to backport).
> >
> > My rationale is that if people will inevitably get the behavior change
> > when they upgrade their kernel, I'd rather they get it sooner rather
> > than later, before more users start depending on the old behavior.
> >
> > I am guessing there is a chance this is not what backports are meant
> > for. Andrew, any thoughts on this?
>
> I agree.  It does depend on how long the old behavior has been out in
> the field, and on our assessment of how many people are likely to
> inconvenienced.  So... yes please, what is that Fixes:?
>

It's commit 501a06fe8e4c ("zswap: memcontrol: implement zswap
writeback disabling"). It landed in v6.8.

I suspect there aren't many users that depend on the old behavior so
far, so I would prefer to get this backported so that it's less likely
that more (or any) users start depending on the old behavior.