On Mon, 10 Dec 2007, Kurt Schreiner wrote:
> on my dual opteron system a kernel compiled from fresh -current
> sources hangs during "build.sh ... -j8 ... distribution".
> Breaking to "db>" yields:
>
> Mon Dec 10 16:39:01 MET 2007
>
> NetBSD/amd64 (isunopti) (console)
>
> login: Stopped in pid 0.2 (system) at  netbsd:breakpoint+0x1:  ret
> db{0}> bt
> breakpoint() at netbsd:breakpoint+0x1
> Xintr_ioapic_edge4() at netbsd:Xintr_ioapic_edge4+0xd8
> --- interrupt ---
> _kernel_lock() at netbsd:_kernel_lock+0xe3
> intr_biglock_wrapper() at netbsd:intr_biglock_wrapper+0x18
> Xintr_ioapic_level18() at netbsd:Xintr_ioapic_level18+0xe0
> --- interrupt ---
> _kernel_lock() at netbsd:_kernel_lock+0xe3
> trap() at netbsd:trap+0x769
>
> and than nothing, even db doesn't prompt again for input.
> Only the power switch brings the system back to live...

I'm seeing similar behaviour on a Core 2 Duo with a UP kernel, except at 
boot when launching gdm. This didn't happen until I upgraded my userland 
from 4.99.38-39 vintage to 4.99.42.

Cheers,
Jared