hangup (livelock) - db> prompt in endless loop

[Paul B. Mahol]

On 12/17/08, Alexey Shuvaev <shuvaev at physik.uni-wuerzburg.de> wrote:
> 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 :(

Looks like syscons problem, does it happen with kern.smp.disabled=1?

-- 
Paul