Re: [PATCH memcg 0/1] false global OOM triggered by memcg-limited task

From: Shakeel Butt
Date: Tue Oct 19 2021 - 01:33:43 EST


On Mon, Oct 18, 2021 at 11:52 AM Vasily Averin <vvs@xxxxxxxxxxxxx> wrote:
>
> On 18.10.2021 18:07, Shakeel Butt wrote:
> > On Mon, Oct 18, 2021 at 5:27 AM Michal Hocko <mhocko@xxxxxxxx> wrote:
> >>
> >> [restore the cc list]
> >>
> >> On Mon 18-10-21 15:14:26, Vasily Averin wrote:
> >>> On 18.10.2021 14:53, Michal Hocko wrote:
> >>>> On Mon 18-10-21 13:05:35, Vasily Averin wrote:
> >>>>> On 18.10.2021 12:04, Michal Hocko wrote:
> >>>>> Here we call try_charge_memcg() that return success and approve the allocation,
> >>>>> however then we hit into kmem limit and fail the allocation.
> >>>>
> >>>> Just to make sure I understand this would be for the v1 kmem explicit
> >>>> limit, correct?
> >>>
> >>> yes, I mean this limit.
> >>
> >> OK, thanks for the clarification. This is a known problem. Have a look
> >> at I think we consider that one to 0158115f702b ("memcg, kmem: deprecate
> >> kmem.limit_in_bytes"). We are reporting the deprecated and to-be removed
> >> status since 2019 without any actual report sugested by the kernel
> >> message. Maybe we should try and remove it and see whether that prompts
> >> some pushback.
> >>
> >
> > Yes, I think now should be the right time to take the next step for
> > deprecation of kmem limits:
> > https://lore.kernel.org/all/20201118175726.2453120-1-shakeelb@xxxxxxxxxx/
>
> Are you going to push it to stable kernels too?
>

Not really. Is there a reason I should? More exposure to catch breakage?