Re: [BUG] 2.6.21-rc1,2,3 regressions on my system that I found so far

Thomas Gleixner
2007-03-16T23:37:56Z

Maxim,

On Fri, 2007-03-16 at 12:30 +0200, Maxim Levitsky wrote:
> 3) Sometimes I get this (once in three boots or so)
>
> [ 36.217405] ENABLING IO-APIC IRQs
> [ 36.217587] ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1
> [ 36.433917] APIC timer disabled due to verification failure.
>
> And NO_HZ is disabled due to that (I get 1000/s timer's interrupts)
> I haven't investigated that yet.
> It looks like another new test that my hardware fails to perform...

Yes, this is probably caused by SMM code trying to emulate a PS/2
keyboard from a (maybe connected or not) USB keyboard. Unfortunately we
have no way to disable this BIOS misfeature in the early boot process.
Arjan, Len ?????

I built in this test to rule out bogus LAPIC timer calibration values
which are sometimes off by factor 2-10.

But I also built in a calibration against the PM-Timer, which turned out
to be quite reliable and I think the additional verification step is
only necessary for sytems without PM-Timer.

That was a bit over cautious from my side. I send a patch to avoid this
when PM-Timer is available in a separate mail.

tglx