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

Tobias Oetiker
2009-10-20T12:58:51Z

Hi Mel,

Today Mel Gorman wrote:

> 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?

5 as well ... before an after ...

> > 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.

you are saing that the problem might be even older ?

we do have 8GB ram and 16 GB swap, so it should not fail to allocate all that
often

top - 14:58:34 up 19:54, 6 users, load average: 2.09, 1.94, 1.97
Tasks: 451 total, 1 running, 449 sleeping, 0 stopped, 1 zombie
Cpu(s): 3.5%us, 15.5%sy, 2.0%ni, 72.2%id, 6.5%wa, 0.1%hi, 0.3%si, 0.0%st
Mem: 8198504k total, 7599132k used, 599372k free, 1212636k buffers
Swap: 16777208k total, 83568k used, 16693640k free, 610136k cached

cheers
tobi

--
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi@oetiker.ch ++41 62 775 9902 / sb: -9900