2.4.10-pre15 -> final breaks IOAPIC on UP?

[Matthias Andree <matthias.andree@stud.uni-dortmund.de>]

Hi,

I recently reported difficulties with several 2.4.9-ac and
2.4.10-vanilla versions that froze solid when exiting an X11 display and
returning to text-mode display (XFree 4.1.0, Diamond V550 (Riva TNT)
with nv driver), not even SysRq would help.

After some research (took several hours worth of trail & error), I think
I found the culprit, but first look at the figures. All share the same
configuration which I can provide on request, which includes IOAPIC
support on Uniprocessor machines (Duron/700 in Gigabyte 7ZX-R here):

2.4.9: ok
2.4.10-pre7: ok
2.4.10-pre12: ok
2.4.10-pre14: ok
2.4.10-pre15: ok
2.4.10-final: broken, freezes
2.4.10-final: ok if compiled without IOAPIC support on UP.

So, I believe that any IOAPIC related change between 2.4.10-pre15 and
2.4.10-final breaks my X11 here.

Any comments?

-- 
Matthias Andree

"Those who give up essential liberties for temporary safety deserve
neither liberty nor safety." - Benjamin Franklin