On Thursday, September 13, 2007, Chris Snook wrote:
quoted text
> Jesse Barnes wrote:
> > I just narrowed down a weird problem where I was losing more than
> > 50% of my vblank interrupts to what seems to be the hires timers
> > patch.  Stock 2.6.23-rc5 works fine, but the latest (171) kernel
> > from rawhide drops most of my interrupts unless I also have another
> > interrupt source running (e.g. if I hold down a key or move the
> > mouse I get the expected number of vblank interrupts, otherwise I
> > get between 3 and 30 instead of the expected 60 per second).
> >
> > Any ideas?  It seems like it might be bad APIC programming, but I
> > haven't gone through those mods to look for suspects...
>
> What happens if you boot with 'noapic' or 'pci=nomsi'?  Please post
> dmesg as well so we can see how the kernel is initializing the
> relevant hardware.

noapic gives me the same behavior as nohz=off and pci=nomsi doesn't seem 
to do anything (still get the same lossy interrupts behavior).

dmesg from stock booth (i.e. lossy problem) attached.

Jesse