Ok, this is likely old news but whenever I update my kernel, I try an
MP version too:

Booting netbsd.mp
2250630+111272+325532 [68+143248+106435]=0x2dd328
OBP version 3, revision 2.25 (plugin rev 2)
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001
    The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
    The Regents of the University of California.  All rights reserved.

NetBSD 1.5S (TOO.MP) #0: Mon Feb 19 23:05:25 PST 2001
    root@too:/l0/NetBSD/obj/sys/compile/TOO.MP
total memory = 159 MB
avail memory = 144 MB
using 896 buffers containing 8264 KB of memory
bootpath: /iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000/esp@f,800000/sd@3,0
mainbus0 (root): SUNW,SPARCstation-20
cpu0 at mainbus0: mid 8: RT620/625 @ 100 MHz, on-chip FPU
cpu0: 256K byte write-back, 64 bytes/line, sw flush: cache enabled
cpu1 at mainbus0: mid 9: RT620/625 @ 100 MHz, on-chip FPU
cpu1: 256K byte write-back, 64 bytes/line, sw flush: cache enabled
obio0 at mainbus0
clock0 at obio0 slot 0 offset 0x200000: mk48t08: hostid 72725820
timer0 at obio0 slot 0 offset 0x300000 delay constant 48
zs0 at obio0 slot 0 offset 0x100000 level 12 softpri 6
zstty0 at zs0 channel 0 (console i/o)
zstty1 at zs0 channel 1
zs1 at obio0 slot 0 offset 0x0 level 12 softpri 6
kbd0 at zs1 channel 0
ms0 at zs1 channel 1
fdc0 at obio0 slot 0 offset 0x700000 level 11: no drives attached
auxreg0 at obio0 slot 0 offset 0x800000
power0 at obio0 slot 0 offset 0xa01000 level 2
iommu0 at mainbus0 ioaddr 0xe0000000: version 0x3/0x1, page-size 4096, range 64MB
sbus0 at iommu0: clock = 25 MHz
dma0 at sbus0 slot 15 offset 0x400000: rev 2
esp0 at dma0 slot 15 offset 0x800000 level 4: ESP100A, 40MHz, SCSI ID 7
scsibus0 at esp0: 8 targets, 8 luns per target
ledma0 at sbus0 slot 15 offset 0x400010: rev 2
le0 at ledma0 slot 15 offset 0xc00000 level 6: address 08:00:20:72:58:20
le0: 8 receive buffers, 2 transmit buffers
bpp0 at sbus0 slot 15 offset 0x4800000 level 2 (ipl 3): rev 2
SUNW,DBRIe at sbus0 slot 14 offset 0x10000 level 9 not configured
qec0 at sbus0 slot 2 offset 0x20000 level 4 (ipl 7): 128K memory
qe0 at qec0 slot 0 offset 0x0 rev 1 address 08:00:20:72:58:20
qe1 at qec0 slot 1 offset 0x0 rev 1 address 08:00:20:72:58:20
qe2 at qec0 slot 2 offset 0x0 rev 1 address 08:00:20:72:58:20
qe3 at qec0 slot 3 offset 0x0 rev 1 address 08:00:20:72:58:20
eccmemctl0 at mainbus0: version 0x0/0x2
scsibus0: waiting 2 seconds for devices to settle...
esp0: target 3: sync negotiation
sd0 at scsibus0 target 3 lun 0: <SEAGATE, ST34371W SUN4.2G, 7462> SCSI2 0/direct fixed
sd0(esp0:3:0): max sync rate 8.06MB/s
sd0: 4094 MB, 3882 cyl, 16 head, 135 sec, 512 bytes/sect x 8385121 sectors
IPsec: Initialized Security Association Processing.
root on sd0a dumps on sd0b
root file system type: ffs
panic: lockmgr: no context
syncing disks... done
Frame pointer is at 0xf61c8ac0
Call traceback:
...

It didn't successfully dump either.

I've not looked at Bill's i386-mp branch since I don't have the
hardware, but I've been assuming that when that gets merged in, would
be a good time to start actually trying to debug some of this on the
sparc.  

--sjg