Re: Kernel falls apart under light memory pressure (i.e. linking vmlinux)

[KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>]

On Wed, 18 May 2011 22:15:53 -0400
Andrew Lutomirski <luto@mit.edu> wrote:

> On Wed, May 18, 2011 at 1:17 AM, Minchan Kim <minchan.kim@gmail.com> wrote:
> > On Wed, May 18, 2011 at 4:22 AM, Andrew Lutomirski <luto@mit.edu> wrote:

> > Andrew, Could you test this patch with !pgdat_balanced patch?
> > I think we shouldn't see OOM message if we have lots of free swap space.
> >
> > == CUT_HERE ==
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index f73b865..cc23f04 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -1341,10 +1341,6 @@ static inline bool
> > should_reclaim_stall(unsigned long nr_taken,
> > A  A  A  A if (current_is_kswapd())
> > A  A  A  A  A  A  A  A return false;
> >
> > - A  A  A  /* Only stall on lumpy reclaim */
> > - A  A  A  if (sc->reclaim_mode & RECLAIM_MODE_SINGLE)
> > - A  A  A  A  A  A  A  return false;
> > -
> > A  A  A  A /* If we have relaimed everything on the isolated list, no stall */
> > A  A  A  A if (nr_freed == nr_taken)
> > A  A  A  A  A  A  A  A return false;
> >
> >
> >
> > Then, if you don't see any unnecessary OOM but still see the hangup,
> > could you apply this patch based on previous?
> 
> With this patch, I started GNOME and Firefox, turned on swap, and ran
> test_mempressure.sh 1500 1400 1.  Instant panic (or OOPS and hang or
> something -- didn't get the top part).  Picture attached -- it looks
> like memcg might be involved.  I'm running F15, so it might even be
> doing something.
> 

Hmm, what kernel version do you use ?
I think memcg is not guilty because RIP is shrink_page_list().
But ok, I'll dig this. Could you give us your .config ?

Thanks,
-Kame


> I won't be able to get netconsole dumps until next week because I'm
> out of town and only have this one computer here.
> 
> I haven't tried the other patch.
> 
> Also, the !pgdat_balanced fix plus the if (need_resched()) return
> false patch just hung once on 2.6.37-rc9.  I don't know what triggered
> it.  Maybe yum.
> 
> --Andy

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