Dtrace: hotkernel+buildworld -> crash

Hi,

I'm not sure if it's a known issue or not, but running hotkernel
script from DTraceToolkit-0.99
during "make buildworld -j8" easily crashes -current  (cvsup'ed on Oct
20th) on amd64 (Quad core Q9450)
when I press ^C to stop the script.

Kernel is GENERIC with WITNESS/INVARIANTS disabled and some
SCSI/wireless/NIC drivers removed.

I was unable to dump kernel core - debugger always gets another trap
and returns
to the prompt. The box does not have serial ports, so I've typed in
portions of stack
traces below from the screen.

One common thing across all crashes I've seen so far is that crashed
process always
dies in the same place with the following backtrace. Apparently it attempts to
dereference $rip which is 0.

cyclic_disable_xcall+0x7
smp_rendezvous_action
Xrendezvous
----interrupt

Dtrace process itself always has the same stack trace:

smp_tlb_shootdown
pmap_invalidate_page
pmap_remove_pte
pmap_remove
vm_map_delete
vm_map_remove
uma_large_free
free
dtrace_buffer_free
dtrace_state_destroy
dtrace_close
...

I'll try to reproduce the issue with WITNESS/INVARIANTS turned ON. Perhaps that
would provide more hints on what's wrong. Meanwhile, if someone can suggest
anything I can do to help troubleshoot this, that would be great as
I'm a bit out of
my depth here.

-- 
--Artem