EF> uvm_fault(0xffff80004e263b10, 0x10, 2)-> e
EF> kernel: page fault trap, code=0
EF> Stopped in pid 8186.1 (tar) at netbsd:dqget+0x118 movq %rdx,0(%rax)

PC> What is the corresponding source line in the kernel sources?
Well, that's the MD code (sys/arch/amd64/amd64/trap.c) dropping into DDB
after the MI code (sys/uvm/uvm_fault.c) returned an error.

PC> Do you have netbsd.gdb from this kernel?
Yes (or I can build it easily).
The problem is I don't get a backtrace. Neither from DDB nor gdb.
The second problem is I don't know anything about UVM.

PC> What type of filesystem was this on?
FFSv2.