Re: [PATCH v3 2/4] mm/oom: handle remote ooms

Shakeel Butt
2021-11-16T21:55:54Z

On Tue, Nov 16, 2021 at 1:27 PM Mina Almasry <almasrymina@google.com> wrote:
>
> On Tue, Nov 16, 2021 at 3:29 AM Michal Hocko <mhocko@suse.com> wrote:
[...]
> > Yes, exactly. I meant that all this special casing would be done at the
> > shmem layer as it knows how to communicate this usecase.
> >
>
> Awesome. The more I think of it I think the ENOSPC handling is perfect
> for this use case, because it gives all users of the shared memory and
> remote chargers a chance to gracefully handle the ENOSPC or the SIGBUS
> when we hit the nothing to kill case. The only issue is finding a
> clean implementation, and if the implementation I just proposed sounds
> good to you then I see no issues and I'm happy to submit this in the
> next version. Shakeel and others I would love to know what you think
> either now or when I post the next version.
>

The direction seems reasonable to me. I would have more comments on
the actual code. At the high level I would prefer not to expose these
cases in the filesystem code (shmem or others) and instead be done in
a new memcg interface for filesystem users.