hangup (livelock) - db> prompt in endless loop

[Alexey Shuvaev]

On Tue, Dec 16, 2008 at 06:11:34PM +0300, Anton Yuzhaninov wrote:
> My box with fresh current sometimes stops to respond.
>
> On screen in endless loop printed debugger prompt
>
> db>
>
> but I can't type anything here.
>
> Alt+Ctrl+Esc and Alt+Ctrl+Del don't stops this loop.
>
> How I can debug this problem?
>
> system: current from Mon Dec 15 16:16:23 MSK 2008 with GENERIC kernel, amd64, SMP.
>
Me too!

The system is:
# uname -a
FreeBSD wep4035 8.0-CURRENT FreeBSD 8.0-CURRENT #0: Mon Dec 15 14:21:48 CET 2008
     root at wep4035:/usr/obj/usr/src/sys/USB2  amd64

It can hang even in single user mode with only / mounted read-only,
but with already configured network (msk). I have never seen how it
happens, however :(

Alexey.