Re: Hang: 2.6.32.4 sky2/DMAR (was [PATCH] sky2: Fix WARNING: atlib/dma-debug.c:902 check_sync)

[Michael Breuer]

On 1/28/2010 5:34 PM, Jarek Poplawski wrote:
> On Thu, Jan 28, 2010 at 01:46:17PM -0500, Michael Breuer wrote:
>    
> > On 1/28/2010 12:08 PM, Stephen Hemminger wrote:
> >      
> > > --- a/lib/dma-debug.c	2010-01-20 15:22:55.919519883 -0800
> > > +++ b/lib/dma-debug.c	2010-01-20 15:26:31.648895638 -0800
> > > @@ -285,11 +285,9 @@ static struct dma_debug_entry *hash_buck
> > >   	}
> > >
> > >   	/*
> > > -	 * If we have multiple matches but no perfect-fit, just return
> > > -	 * NULL.
> > > +	 * If we have multiple matches but no perfect-fit
> > > +	 * return best value and let caller deal with it.
> > >   	 */
> > > -	ret = (matches == 1) ? ret : NULL;
> > > -
> > >   	return ret;
> > >   }
> > >
> > >        
> > Ok - applied. Noise gone... however I'm not sure whether I'll be
> > able to keep dma-debug going long enough to catch anything.
> > num_free_entries keeps dropping... looks like entries are not freed.
> > I'm running with a huge number for now&  sky2 as the driver filter.
> > Is there a reason that entries wouldn't be unmapped, or is
> > dma-debug.c just not processing the unmap correctly?
> >      
> Do you mean it's after this patch or earlier too? I think you might
> use my sky2/receive_copy/pci_unmap_len patch instead to get rid of
> this warning.
>
> Btw, since 1000 was too much, maybe you could try copybreak=256 yet,
> plus additional ping or some other source of shorter packets. And how
> about trying this new switch?
>
> Jarek P.
>    
This is with the pci_unmap_len patch as well as the dma-debug patch. I'm 
not getting any warnings - but dma-debug num-free-entries drops until 
zero and then debugging is disabled. I started with 8,000,000 about 
three hours ago - without load I'm already down to less than half that. 
Again - only looking at sky2. Looks like the dma-debug hash table is 
reducing one entry for every packet, but never increasing the 
num_entries (no unmap perhaps).
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