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

K.R. Foley
2005-07-12T16:20:34Z

Ingo Molnar wrote:
> * 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
>

Well I have booted -27 a couple of times and -28 once now without
supplying the noapic boot option and I haven't seen any of the keyboard
repeat problems that I reported late last week. This was on my dual 2.6
Xeon w/HT. I have never seen this behavior on any of my older systems.
Because of the fact that the problem showed up sporadically, I can't say
for sure that it is gone. However, so far so good. I will report any
changes that I see.

--
kr