Re: [Bug #14141] order 2 page allocation failures (generic)

Mel Gorman
2009-10-20T12:51:33Z

On Tue, Oct 20, 2009 at 01:44:50PM +0200, Tobias Oetiker wrote:
> Hi Mel,
>
> Today Mel Gorman wrote:
>
> > On Mon, Oct 19, 2009 at 10:17:06PM +0200, Tobias Oetiker wrote:
>
> > > Oct 19 22:09:52 johan kernel: [11157.121600] [<ffffffff813ebd42>] skb_copy+0x32/0xa0 [kern.warning]
> > > Oct 19 22:09:52 johan kernel: [11157.121615] [<ffffffffa07dd33c>] vboxNetFltLinuxPacketHandler+0x5c/0xd0 [vboxnetflt] [kern.warning]
> > > Oct 19 22:09:52 johan kernel: [11157.121620] [<ffffffff813f2512>] dev_hard_start_xmit+0x142/0x320 [kern.warning]
> >
> > Are the number of failures at least reduced or are they occuring at the
> > same rate?
>
> not that it would have any statistical significance, but I had 5
> failure (clusters) yesterday morning and 5 this morning ...
>

Before the patches were applied, how many failures were you seeing in
the morning?

> the failures often show up in groups I saved one on
> http://tobi.oetiker.ch/cluster-2009-10-20-08-31.txt
>
> > Also, what was the last kernel that worked for you with this
> > configuration?
>
> that would be 2.6.24 ... I have not upgraded in quite some time.
> But since the io performance of 2.6.31 is about double in my tests
> I thought it would be a good thing todo ...
>

That significant a different in performance may explain differences in timing
as well. i.e. the allocator is being put under more pressure now than it
was previously as more processes make forward progress.

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab