Re: High cpu temperature with 2.6.32, bisection shows commit 69d258 (fwd)

From: Arjan van de Ven
Date: Sat Jan 09 2010 - 23:14:00 EST

On Sat, 9 Jan 2010 18:07:14 -0800
Ray Lee <ray-lk@xxxxxxxxxxxxx> wrote:

> On Sat, Jan 9, 2010 at 4:42 PM, Arjan van de Ven
> <arjan@xxxxxxxxxxxxx> wrote:
> > basically it appears that your machine, when the kernel asks for C2,
> > exits C2 immediately again.
> >
> > The old algorithm somehow caught this and stopped asking for C2
> > most of the time; the new algorithm doesn't see any activity and
> > asks for C2 again.
> This change of behavior will certainly bite more users out there. Is
> there any way we can detect the systems that aren't honoring the C2
> request and limit back to C1?

it's not very likely that there are many such systems; it takes work to
break C2....
so far in 6 months 2 systems showed up, and this includes a fedora

on the other hand, it's not so easy to detect the situation; exiting c2
quickly can also happen in normal use, so we'd have to have some sort of
threshold, which will be fragile by itself.

Arjan van de Ven Intel Open Source Technology Centre
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