Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone

From: Michal Hocko
Date: Wed Feb 22 2017 - 02:55:13 EST


On Wed 22-02-17 11:02:21, Tetsuo Handa wrote:
> Michal Hocko wrote:
> > On Tue 21-02-17 23:35:07, Tetsuo Handa wrote:
> > > Michal Hocko wrote:
> > > > OK, so it seems that all the distractions are handled now and linux-next
> > > > should provide a reasonable base for testing. You said you weren't able
> > > > to reproduce the original long stalls on too_many_isolated(). I would be
> > > > still interested to see those oom reports and potential anomalies in the
> > > > isolated counts before I send the patch for inclusion so your further
> > > > testing would be more than appreciated. Also stalls > 10s without any
> > > > previous occurrences would be interesting.
> > >
> > > I confirmed that linux-next-20170221 with kmallocwd applied can reproduce
> > > infinite too_many_isolated() loop problem. Please send your patches to linux-next.
> >
> > So I assume that you didn't see the lockup with the patch applied and
> > the OOM killer has resolved the situation by killing other tasks, right?
> > Can I assume your Tested-by?
>
> No. I tested linux-next-20170221 which does not include your patch.
> I didn't test linux-next-20170221 with your patch applied. Your patch will
> avoid infinite too_many_isolated() loop problem in shrink_inactive_list().
> But we need to test different workloads by other people. Thus, I suggest
> you to send your patches to linux-next without my testing.

I will send the patch to Andrew later after merge window closes. It
would be really helpful, though, to see how it handles your workload
which is known to reproduce the oom starvation.
--
Michal Hocko
SUSE Labs