Re: iwlagn: order 2 page allocation failures

[Mel Gorman <mel@csn.ul.ie>]

On Thu, Sep 10, 2009 at 11:18:42AM +0300, Pekka Enberg wrote:
> On Wed, 2009-09-09 at 17:55 +0100, Mel Gorman wrote:
> > On Wed, Sep 09, 2009 at 05:59:30PM +0200, Frans Pop wrote:
> > > On Wednesday 09 September 2009, Mel Gorman wrote:
> > > > Franz, in the full dmesg was there any mention of "SLUB: Unable to
> > > > allocate memory on node"?
> > > 
> > > No, nothing at all. I double checked the kernel log, but it was completely 
> > > quiet in the hours before and after the messages I already posted.
> > > 
> > 
> > Ok, that in itself is unexpected.
> > 
> > Pekka, it looks from the stack trace that the failure is from
> > __alloc_skb and I am guessing the failure path is around here
> > 
> >         size = SKB_DATA_ALIGN(size);
> >         data = kmalloc_node_track_caller(size + sizeof(struct skb_shared_info),
> >                         gfp_mask, node);
> >         if (!data)
> >                 goto nodata;
> > 
> > Why would the SLUB out-of-memory message not appear? It's hardly
> > tripping up on printk_ratelimit() is it?
> 
> That's because it's a large allocation that's passed directly to the
> page allocator. See kmalloc_large_node(), for example.
> 

Pants. Is there any chance that could be fixed so that allocation
failures within SLUB get consistently reported?

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