Jarek Poplawski wrote:

On Fri, Dec 22, 2006 at 06:05:18AM -0800, Ben Greear wrote:

quoted

Jarek Poplawski wrote:

quoted

On Fri, Dec 22, 2006 at 08:13:08AM +0100, Jarek Poplawski wrote:

quoted

On 20-12-2006 03:13, Ben Greear wrote:

quoted

This is from 2.6.18.2 kernel with my patch set.  The MAC-VLANs are in 
active use.
From the backtrace, I am thinking this might be a generic problem, 
however.

Any ideas about what this could be?  It seems to be reproducible every 
day or

...

quoted

If it doesn't help, I hope lockdep will be more
precise when you'll upgrade to 2.6.19 or higher.

... or when you enable lockdep in 2.6.18 (I've
forgotten it's there alredy!).

I got lucky..the system was available by ssh still.  I see this in the boot 
logs..I assume
this means lockdep is enabled?  Should I have expected to see a lockdep 
trace in the case of
his soft-lockup then?

.....
Dec 19 04:33:48 localhost kernel: Lock dependency validator: Copyright (c) 
2006 Red Hat, Inc., Ingo MolnarDec 19 04:33:48 localhost kernel: ... 
MAX_LOCKDEP_SUBCLASSES:    8

Yes, you got it enabled in the config.

If there is no message later about validator
turning off and no warnings which could point
at lockdep then it is working.

But then, IMHO, there is rather small probability
this bug is really from lockup. Another possibility
is hardware irqs (timer in particular) are turned
off by something (maybe those hacks?) for extremely
long time (~10 sec.). 

The system hangs and does not recover (well, a few processes
continue on the other processor for a few minutes before they
too deadlock...)

I am guessing this problem has been around for a while, but it
is only triggered when interfaces are created, and probably only
when UDP traffic is already running heavily on the system.  Most
systems w/out virtual devices will not trigger this sort of
race.

Ben

 
Regards,
Jarek P.

-- 
Ben Greear [off-list ref]
Candela Technologies Inc  http://www.candelatech.com