Re: 2.6.31-rc5 regression: x86 MCE malfunction on Thinkpad T42p

From: Ingo Molnar
Date: Mon Aug 10 2009 - 09:32:16 EST



* Johannes Stezenbach <js@xxxxxxxxx> wrote:

> On Mon, Aug 10, 2009 at 02:32:28PM +0200, Andi Kleen wrote:
> > > > The appended patch should remove the warning. Can you please test it?
> > >
> > > It works (no more warning), but I feel I'm better off using "lapic"
> >
> > Thanks for testing.
> >
> > > because it enables thermal monitoring and performance counters.
> >
> > When the BIOS doesn't enable it then force enabling lapic might not work.
> >
> > This could cause either boot failures (obvious) or more subtle
> > problems like SMM doing something unexpected. Just saying that
> > if you have strange problems later first try disabling this
> > option again.
>
> Thanks for the heads-up. I remember I tried to use oprofile in
> the past on this machine and was disappointed that it only got the
> timer event. I'll keep lapic for now unless I see signs of
> instability.

What's the output of something like 'perf stat true', and does 'perf
top' output something - i.e. do perfcounters work in general? Once
you get to that stage and it works then it should be fine.

Ingo
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