Re: [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts

[David Dillow <dave@thedillows.org>]

On Sat, 2009-08-22 at 05:07 -0700, Eric W. Biederman wrote:
> ebiederm@xmission.com (Eric W. Biederman) writes:
> 
> > David Dillow <dave@thedillows.org> writes:
> >
> >>
> >> Re-looking at the code, I'd guess that some IRQ status line is getting
> >> stuck high, but I don't see why -- we should acknowledge all outstanding
> >> interrupts each time through the loop, whether we care about them or
> >> not.
> >>
> >> Could reproduce a problem with the following patch applied, and send the
> >> full dmesg, please?
> >
> > Here is what I get.
> >
> > r8169 screaming irq status 00000085 mask 0000ffff event 0000803f napi 0000001d
> 
> And now that the machine has come out of it, that was followed by:
> Looks like the soft lockup did not manage to trigger in this case.

I need some more context, please. What is the network load through this
NIC when you have the issues? Light, heavy? Can you give me more details
about the machine? A full dmesg from boot until this happens would help
quite a bit. At a minimum it would help answer which version of the chip
we're dealing with and what the machine it is in looks like.

Can you reproduce this with pci=nomsi? I'm assuming it the chip running
in MSI mode.

Also, can you reproduce it when booting UP (or maxcpus=1)? I'm thinking
about a race between rtl8169_interrupt() and rtl8169_poll(), but it
isn't jumping out at me.

Also, I'm having connectivity troubles this weekend, so my response may
be spotty. :(