A data point in case it is of interest.  I just booted a 1.4X sparc/MP
kernel (output below).

The same kernel config (sans MULTIPROCESSOR and DIAGNOSTIC) compiled
at the same time, booted and is working ok.

--sjg

...
Keyboard not present.  Using tty for input and output.

SPARCstation 20 MP (2 X RT625), No Keyboard
ROM Rev. 2.25R hyperSPARC, 160 MB memory installed, Serial #7493664.
Ethernet address 8:0:20:72:58:20, Host ID: 72725820.



Rebooting with command: netbsd.MP -s                                  
Boot device: /iommu/sbus/espdma@f,400000/esp@f,800000/sd@3,0  File and args: netbsd.MP -s
>> NetBSD/sparc Secondary Boot, Revision 1.9
>> (pk@dolphin, Sat Aug  7 02:01:08 MEST 1999)
Booting netbsd.MP
2090836+116520+328812 [68+134544+98609]=0x2b43b8
entry: 0x4000, bootinfo: 0x2b83b8
bootinfo[0]=0x2b87b8; bootinfo[1]=0x2b83c0
nsym=0x1, ssym=0x27f2ec, esym=0x2b83b8
OBP version 3, revision 2.25 (plugin rev 2)
Copyright (c) 1996, 1997, 1998, 1999, 2000
    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 1.4X (TOO.MP) #2: Sat Apr 29 02:31:38 EST 2000
    root@too.quick.com.au:/l0/NetBSD/obj/u3/NetBSD/current/src/sys/arch/sparc/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 (eeprom)
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: ESP200, 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...
probe(esp0:3:0): max sync rate 10.00MB/s
sd0 at scsibus0 target 3 lun 0: <SEAGATE, ST34371W SUN4.2G, 7462> SCSI2 0/direct fixed
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... 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 giving up
Frame pointer is at 0xf4f88ab8
Call traceback:
  pc = 0xf01a446c  args = (0x1e0010e0, 0x1e001fe0, 0x0, 0xf01df400, 0xf021cc00, 0x5, 0xf4f88b20) fp = 0xf4f88b20
  pc = 0xf004cc1c  args = (0x100, 0x0, 0xf021d400, 0x0, 0x0, 0x0, 0xf4f88b88) fp = 0xf4f88b88
  pc = 0xf003c5a8  args = (0xf01db068, 0x100, 0x1, 0xeefb595f, 0xd1dbbfe5, 0xf8081, 0xf4f88bf0) fp = 0xf4f88bf0
  pc = 0xf0159c2c  args = (0xf0235304, 0x1, 0xfffffffe, 0x0, 0xf027c400, 0xf0235300, 0xf4f88c58) fp = 0xf4f88c58
  pc = 0xf01af1b0  args = (0x5, 0xf0d2b000, 0x0, 0x2, 0xffffffff, 0xaaaaaaaa, 0xf4f88d90) fp = 0xf4f88d90
  pc = 0xf0006254  args = (0x9, 0x3a6, 0xf0d2b000, 0xf4f88e98, 0x40, 0x0, 0xf4f88e38) fp = 0xf4f88e38
  pc = 0xf01a3824  args = (0xf0d2b000, 0x6, 0x3f, 0xf027cc00, 0x40, 0x0, 0xf4f88ee8) fp = 0xf4f88ee8
  pc = 0xf00069a0  args = (0x0, 0x80000000, 0xf0222800, 0xf01a36cc, 0xedfe200, 0x600606, 0xf4f88f50) fp = 0xf4f88f50
  pc = 0xf00072fc  args = (0xf0740f40, 0x0, 0x0, 0x0, 0x0, 0x0, 0xf4f84f50) fp = 0xf4f84f50

dumping to dev 7,1 offset 286887
dump sd0(esp0:3:0): esp0: timed out [ecb 0xf074690c (flags 0x1, dleft 200, stat 0)], <state 2, nexus 0xf07468d8, phase(l 10, c 100, p 3), resid 0, msg(q 0,o 0) >
sd0(esp0:3:0): ncr53c9x_abort: not NEXUS
sd0(esp0:3:0): max sync rate 10.00MB/s
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 succeeded
rebooting

Savecore didn't find anything.