I have the "LOCKDEBUG spl fix" in, and haven't seen a single xcall
   message since.  (But I have LOCKDEBUG in too.)  I have had it freeze
   up twice though.  Both times it was bad enough that the BLINK option
   didn't blink the power light anymore.  The first time it was bad
   enough that I couldn't get into DDB either...  Don't know what to
   look for once I'm in DDB and I can't get a good dump either, since
   everything always panic's at the end of a shutdown.


few commands to run:

db{0}> mach cpu
db{0}> t
db{0}> show reg
db{0}> mach cpu 1
db{0}> t
db{0}> show reg

if you are at db{1} use "mach cpu 0".  if you have more than 1 cpus,
do them all...

that should show a reasonable amount of info about what is happening,
and we can go from there...


.mrg.