panic: APIC: Previous IPI is stuck

Brian Fundakowski Feldman green at
Mon Sep 27 14:55:19 PDT 2004

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                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\

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