Re: [Bug #13648] nfsd: page allocation failure

Stephan von Krawczynski
2009-07-31T11:48:43Z

On Thu, 30 Jul 2009 14:30:42 -0700 (PDT)
David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrote:

> On Mon, 27 Jul 2009, Stephan von Krawczynski wrote:
>
> > This is no regression between 2.6.29 and 2.6.30.
> > In fact we could reproduce the problem with kernel versions:
> >
> > 2.6.27.26 < X <= 2.6.30.3
> >
> > (Meaning 2.6.27.26 is the last one _not_ showing the problem).
> >
>
> And 2.6.28.10 is showing the exact same problem as initially reported,
> right?

Yes, that is correct.

> I noticed your /var/log/messages is showing you're using slub as opposed
> to slab (which Justin was using, and causing order-0 allocations errors).
> SLUB uses order-1 allocations for this cache growth and it's failing
> because of memory fragmentation, not because you're truly oom.

Originally I used slab, and as someone wanted me to test slub I tried. The
results looked pretty much the same to me.

> The only thing that is immediately apparent that changed in this path over
> these kernel versions (there were significant changes to e1000e) is the
> CRC stripping. If it's loaded as a module, perhaps you could try
>
> modprobe e1000e CrcStripping=0,0
>
> (assuming you have two adapters).

I will try that.

> I've cc'd some relevant e1000e driver people in the hopes they'll be able
> to diagnose this problem. Memory fragmentation as the result of page
> group changes wouldn't affect order-0 allocations such as this on slab, so
> it's doubtful the VM regressed if you can reproduce the problem with
> CONFIG_SLAB.

I can, as said before, the problem first showed up with slab.

--
Regards,
Stephan