Re: [REGRESSION] Re: [PATCH 6.1 033/219] memcg: drop kmem.limit_in_bytes

From: Michal Hocko
Date: Wed Sep 20 2023 - 16:08:19 EST


On Wed 20-09-23 12:46:23, Shakeel Butt wrote:
> On Wed, Sep 20, 2023 at 9:55 AM Michal Hocko <mhocko@xxxxxxxx> wrote:
> >
> > On Wed 20-09-23 08:32:42, Shakeel Butt wrote:
> > > Also I don't think reverting 58056f77502f would give any benefit.
> >
> > Not reverting 58056f77502f would re-introduce the regression in some
> > non-patched versions of Docker runtimes which cannot handle ENOTSUPP.
> > So I think we need to revert both or none of them. I would prefer the
> > later (option 1) as the fix is trivial but I do understand headache
> > of chasing all those outdated deployments or vendor code forks.
>
> I think that would be too much conservative an approach but I don't

Well, TBH I do not really see any sifference between one set of broken
userspace or the other. Both are making assumptions on our interfaces
and they do not overlap unfortunately.

> have a strong opinion against it. Also just to be clear we are not
> talking about full revert of 58056f77502f but just the returning of
> EOPNOTSUPP, right?

If we allow the limit to be set without returning a failure then we
still have options 2 and 3 on how to deal with that. One of them is to
enforce the limit.

--
Michal Hocko
SUSE Labs