Has anyone seen something like this?

I have one machine that does this with some kernels, repeatbly, but works
fine with others, repeatably as well.

...
Kernelized RAIDframe activated                            
wd0 at atabus0 drive 0panic: lockmgr: no context
kdb breakpoint at 11bbfd0                       
Stopped at      netbsd:cpu_Debugger+0x4:        nop
db> bt                                             
lockmgr(18388a8, 0, 0, 3, a, 1860400) at netbsd:lockmgr+0x1ec
uvmfault_lookup(e0017970, 0, cc0db60, 6, fffffffffffffffc, 0) at netbsd:uvmfault_lookup+0x1b4
uvm_fault(18388a0, 0, 1, 1, 1809510, 1875080) at netbsd:uvm_fault+0x70
data_access_fault(e0017b70, 30, 108f004, 0, 50, 800809) at netbsd:data_access_fault+0x418
?(11d7400, 0, 331be458, 6, fffffffffffffffb, 1) at 0x100871c
__wdccommand_done(28681d0, f007a8cc, 54, 12c, 2, 1fe02c00010) at netbsd:__wdccommand_done+0x1b0
cmd_pci_intr(2868000, 0, e0017ed0, cc0d870, 11964cc, 18750c0) at netbsd:cmd_pci_intr+0xbc
...

This is the only machine doing this to me, and I suspect one of it's
disks is marginal - but I don't see how that would be related.

Martin