XEN3_DOM0 5.99.55 on grinds to a halt shortly after boot (repeatedly)

[Johan Ihrén <johani%johani.org@localhost>]

Hi,

This is 5.99.55 from about July 20th/21st.

Let me start with the observation that this is hardware related, as the same 
exact 5.99.55 disk works like a charm in an older Core 2 Quad machine. But when 
I boot from this disk in a machine with a brand new Core i7 + H67 chipset it 
works "less well".

If I boot the standard XEN3_DOM0 kernel I typically get to the login prompt and 
usually manage to login and give one or two commands before the machine 
basically stops. When I break into DDB it looks like this (typed by hand, no 
serial console):

Stopped in pid 0.2 (system)
breakpoint()
wskbd_translate{}
wskbd_input()
pckbd_input()
pckbcintr()
evtchn_do_event()
call_evtchn_do_event()
hypervisor_callback()
idle_loop()

The interesting thing is that this doesn't look bad to me. This seems to be 
mostly identical to what I'd see if I break into DDB on a machine that's 
working just fine. So what is it doing? I don't know.

Some additional information:

1. If I boot GENERIC it doesn't hang, only XEN3_DOM0 hangs. Furthermore, when 
GENERIC is idling, no services, nothing it is still seeing ~10% interrupts on 
CPU0. That seems to be an awful lot...

2. XEN3_DOM0 grinds to a halt also in single user, although it may take 
slightly longer to get there.

3. "Grinds to a halt" is not the same as "hangs". There is something going on, 
it is just that it has to be measured in geological time units. 

        * Once it happened during fsck and I decided to leave it to it. fsck of 
a 30GB filesystem took several hours (but did complete).

        * I typed "root<RETURN>" at the login prompt when the machine had gone 
catatonic and nothing happened. An hour later there was still no change. But 
the next morning there was the expected "Password:" prompt on the console ;-)

Suggestions for what to try next would be much appreciated.

Regards,

Johan Ihrén