Re: 2.6.36-rc7: net/bridge causes temporary network I/O lockups [2]

From: Patrick Ringl
Date: Mon Oct 18 2010 - 16:37:56 EST


On 10/18/2010 06:16 PM, Herbert Xu wrote:
On Sat, Oct 16, 2010 at 08:15:31PM +0200, Patrick Ringl wrote:
Hi,

okay I narrowed down the issue. I watched all function calls of the
'bridge' module with the help of a small systemtap probe of mine. I
first traced a timespan where the issue did not occur, then one where it
did and composed an intersection of these two:
I can't reproduce this problem here so I'll need your help to
track it down.

Can you see if you can relate the lock-ups to specific events
such as a particular packet being sent through the bridge?
The problem is definitely somewhere in the 2.6.34 commit regarding IGMP snooping (when disabling it, everything works). I have attached a tcpdump log of data coming through the bridge and data coming through an attached port (eth1). The lockups are easily spotted, since I use mtr to constantly ping the problematic machine, and there aren't any incoming/outgoing packets during the lockup.
If we can recreate the problem on demand that that helps us to
find the root cause.

You mentioned that you took packet dumps on the system. If you
can show us the packets through the bridge and its ports when
the problem occurs that would be great.

Thanks,
Anything else I could possibly provide? :-)

regards,
Patrick

Attachment: dump_br0
Description: Binary data

Attachment: dump_eth1
Description: Binary data