Re: Real-Time Preemption, -RT-2.6.12-final-V0.7.50-24

Ingo Molnar
2005-07-12T16:04:03Z

* K.R. Foley <kr@cybsft.com> wrote:

> Ingo Molnar wrote:
> >* Daniel Walker <dwalker@mvista.com> wrote:
> >
> >
> >>I observed a situation on a dual xeon where IOAPIC_POSTFLUSH , if on,
> >>would actually cause spurious interrupts. It was odd cause it's
> >>suppose to stop them .. If there was a lot of interrupt traffic on one
> >>IRQ , it would cause interrupt traffic on another IRQ. This would
> >>result in "nobody cared" messages , and the storming IRQ line would
> >>get shutdown.
> >>
> >>This would only happen in PREEMPT_RT .
> >
> >
> >does it happen with the latest kernel too? There were a couple of things
> >broken in the IOAPIC code in various earlier versions.
> >
> > Ingo
>
> Is this why I have been able to boot the latest versions without the
> noapic option (and without noticeable keyboard repeat problems) or has
> it just been dumb luck?

yes, i think it's related - the IO-APIC code is now more robust than
ever, and that's why any known-broken system would be important to
re-check.

Ingo