On Sat, 2 Feb 2008, Michael L. Hitch wrote:

>  I finally got around to trying out a more current kernel on one my MP 
> alphas, and have problems with hangs.  I can't get tracebacks from the other 
> CPU - most likely because it is spinning on a lock or mutex with interrupts 
> disabled and the IPI to suspend it can not be processed.  A couple of times 
> the halted CPU appears to be in _kernel_lock().  The last
> one appears to be in mutex_vector_enter(), called from pmap_tlb_shootdown(). 
> I have rev 1.231 of pmap.c.

   One other note:  a -current UP kernel seems to work fine.

   I'm now trying a kernel where I've added a SPINLOCK_SPIN_HOOK in 
the places where sys/kern/mutex.c spins, and my MP kernel has been running 
for over 2 hours.  I'm going to try a LOCKDEBUG kernel again after a while
to see if that's changed by the addition of the SPINLOCK_SPIN_HOOKs.


--
Michael L. Hitch			mhitch@NetBSD.org