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

From: Johannes Stezenbach
Date: Tue Aug 11 2009 - 11:40:22 EST


On Tue, Aug 11, 2009 at 12:13:07AM +0200, Johannes Stezenbach wrote:
> On Mon, Aug 10, 2009 at 11:31:33PM +0200, Ingo Molnar wrote:
> > * Johannes Stezenbach <js@xxxxxxxxx> wrote:
> > >
> > > Could the warning be caused by the cpufreq ondemand governor? ISTR
> > > that one should switch to the performance governor before doing
> > > any profiling, but I forgot for this test.
> >
> > there might be a connection - it could in theory cause sched_clock()
> > transients and confuse the ring-buffer time-stamping.
>
> I'll try tomorrow after a fresh boot if the warning also appears
> with the performance governor.

Nope, cpufreq was not the culprit. The "Delta way too big!"
warning in rb_reserve_next_event() happens after suspend-to-RAM.


Johannes
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