Dtrace panic'ed

I was trying to run a simple dtrace profiling script, and
panic'ed the machine using today's -current on an 8-way opteron.

I tried to run:
#!/usr/sbin/dtrace -s

profile:::profile-997
{
         _at_a[stack(20)]=count();
}

END
{
         trunc(_at_a, 20);
         printa(_at_a);
}

Everything was fine until I hit ^C.  This appeared
on the tty (which I expected):

dtrace: script '/nfs/home/gallatin/dtrace/profile_stack.d' matched 2 probes
^C
CPU     ID                    FUNCTION:NAME
   1      2                             :END

               kernel`vm_page_splay+0x5b
               kernel`trap+0x482
               kernel`0xffffffff807eb8f3
                 1

               kernel`vm_fault+0x1e2
                 1

               kernel`pagezero+0x17
                 1

               kernel`cpu_idle+0x1
                 1

               kernel`pmap_enter+0x6f
               kernel`0xffffffff807eb8f3
                 1

                 4

               kernel`pagezero+0x11
                 4

               kernel`acpi_cpu_c1+0x6
               kernel`0xffffffff807ebd4e
             14063

And then the machine fell over with this on console:

kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
cpuid = 7; apic id = 07
fault virtual address   = 0x20
fault code              = supervisor read data, page not present
instruction pointer     = 0x8:0xffffffff80e33187
stack pointer           = 0x10:0xfffffffe4004aa70
frame pointer           = 0x10:0xfffffffe4004aa80
code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = resume, IOPL = 0
current process         = 11 (idle: cpu7)
trap number             = 12
panic: page fault
cpuid = 7
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
panic() at panic+0x182
trap_fatal() at trap_fatal+0x2ad
trap_pfault() at trap_pfault+0x294
trap() at trap+0x38b
calltrap() at calltrap+0x8
--- trap 0xc, rip = 0xffffffff80e33187, rsp = 0xfffffffe4004aa70, rbp = 
0xfffffffe4004aa80 ---
cyclic_disable_xcall() at cyclic_disable_xcall+0x7
smp_rendezvous_action() at smp_rendezvous_action+0xb3
Xrendezvous() at Xrendezvous+0x64
--- interrupt, rip = 0xffffffff807e3cf6, rsp = 0xfffffffe4004ab70, rbp = 
0xfffffffe4004ab80 ---
acpi_cpu_c1() at acpi_cpu_c1+0x6
acpi_cpu_idle() at acpi_cpu_idle+0x19c
sched_idletd() at sched_idletd+0x234
fork_exit() at fork_exit+0x118
fork_trampoline() at fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xfffffffe4004ad40, rbp = 0 ---
Uptime: 5m14s
Physical memory: 8177 MB
Dumping 506 MB: 491 475 459 443 427 411 395 379 363 347 331 315 299 283 
267 251 235 219 203 187 171 155 139 123 107 91 75 59 43 27 11


Cheers,

Drew