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Subject: Re: [PATCH 1/3] Added runqueue clock normalized with cpufreq
From: Dario Faggioli <raistlin@linux.it>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Harald Gustafsson <harald.gustafsson@ericsson.com>,
        Harald Gustafsson <hgu1972@gmail.com>, linux-kernel@vger.kernel.org,
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Date: Fri, 17 Dec 2010 20:16:42 +0100
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On Fri, 2010-12-17 at 19:59 +0100, Peter Zijlstra wrote:=20
> > However, converting the basic mechanism into a CPUfreq governor should
> > be easily doable... The only problem is finding the time for that! ;-P=
=20
>=20
> Ah, I think Harald will solve that for you,.. :)
>=20
Yeah, I saw that... Help is a wonderful thing, you know? :-P

> > And, at least for the meantime, this seems a very very nice solution.
> > The only thing I don't like is that division which would end up in bein=
g
> > performed at each tick/update_curr_dl(), but we can try to find out a
> > way to mitigate this, what do you think Harald?
>=20
> A simple mult and shift-right should do. You can either pre-compute for
> a platform, or compute the inv multiplier in the cpufreq notifier thing.
>
Yeah, I was thinking about something like the last solution you just
propose, but we'll consider all of them.

Thanks and Regards,
Dario

--=20
<<This happens because I choose it to happen!>> (Raistlin Majere)
----------------------------------------------------------------------
Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa  (Italy)

http://retis.sssup.it/people/faggioli -- dario.faggioli@jabber.org

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