Re: [PATCH] mm,page_alloc: PF_WQ_WORKER threads must sleep at should_reclaim_retry().

[Michal Hocko]

On Tue 31-07-18 06:01:48, Tetsuo Handa wrote:
> On 2018/07/31 4:10, Michal Hocko wrote:
> > Since should_reclaim_retry() should be a natural reschedule point,
> > let's do the short sleep for PF_WQ_WORKER threads unconditionally in
> > order to guarantee that other pending work items are started. This will
> > workaround this problem and it is less fragile than hunting down when
> > the sleep is missed. E.g. we used to have a sleeping point in the oom
> > path but this has been removed recently because it caused other issues.
> > Having a single sleeping point is more robust.
> 
> linux.git has not removed the sleeping point in the OOM path yet. Since removing the
> sleeping point in the OOM path can mitigate CVE-2016-10723, please do so immediately.

is this an {Acked,Reviewed,Tested}-by?

I will send the patch to Andrew if the patch is ok. 

> (And that change will conflict with Roman's cgroup aware OOM killer patchset. But it
> should be easy to rebase.)

That is still a WIP so I would lose sleep over it.
-- 
Michal Hocko
SUSE Labs