To: linux-kernel@vger.kernel.org
From: Wes Felter <wesley@felter.org>
Subject: Re: Dual Core on Linux questions
Date: Mon, 20 Mar 2006 13:23:32 -0600
Message-ID: <dvmvge$v43$1@sea.gmane.org>
References: <20060318082434.M33432@linuxwireless.org>
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Alejandro Bonilla wrote:
> Hi,
> 
> I have a few questions about the PM Dual Core and how could it really work
> with Linux. Sorry if there are new patches on LKML about any of these things:
> 
> Could each processor or die, have it's own cpufreq scaling governor?
> 
> Is there a way to allow one die to be idle and let the other one normal?
> 
> So in other words, could we manage these processors speedstep, utilization and
> workload individually?

This depends on your hardware. I was reading the Sossaman data sheet the 
other day, and it says that the entire chip must run at the same 
frequency. You can set each core to a different frequency, but the 
hardware chooses the higher of the two. Likewise, the entire chip can 
sleep, but individual cores can only go into C1. I imagine the Core Duo 
is the same.

IIRC, the dual-core Opterons behave a little differently but the two 
cores still have to run at the same frequency.

Wes Felter - wesley@felter.org

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