panic: APIC: Previous IPI is stuck

[Brian Fundakowski Feldman]

On Mon, Sep 27, 2004 at 04:35:44PM -0400, John Baldwin wrote:
> On Friday 24 September 2004 08:24 pm, Andy Farkas wrote:
> > I have been having this problem for a few weeks now. Glad I'm not the only
> > one. My box is a 4xPPro running 5.3-BETA5. It panics with either ULE
> > or 4BSD.
> >
> > My theory is that a physical IPI gets lost somewhere and the kerenl spins
> > waiting for it. But thats just a stab in the dark because nobody cares to
> > explain why IPI's would be stuck.
> 
> The panic has to do with a previous IPI not finished being sent from the same 
> CPU.  I've yet to determine why this happens.  You can try editing 
> sys/i386/i386/local_apic.c and turning on 'DETECT_DEADLOCK' (I think it is 
> just commented out) and seeing if that improves stability.  I also see this 
> on a 4xPIIXeon system I use for testing.

Can KTR logging be leveraged to find the root cause(s) of these deadlocks,
or is it just so wildly unpredictable that it would be of no use?

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green at FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\