Re: [v6 PATCH 0/7]: cpuidle/x86/POWER: Cleanup idle powermanagement code in x86, cleanup drivers/cpuidle/cpuidle.c and introducecpuidle to POWER.

From: Arjan van de Ven
Date: Thu Sep 24 2009 - 08:25:58 EST


On Thu, 24 Sep 2009 10:42:41 +0530
Arun R Bharadwaj <arun@xxxxxxxxxxxxxxxxxx> wrote:

> * Arun R Bharadwaj <arun@xxxxxxxxxxxxxxxxxx> [2009-09-22 16:55:27]:
>
> Hi Len, (or other acpi folks),
>
> I had a question regarding ACPI-cpuidle interaction in the current
> implementation.
>
> Currently, every cpu (i.e. acpi_processor) registers to cpuidle as
> a cpuidle_device. So every cpu has to go through the process of
> setting up the idle states and then registering as a cpuidle device.
>
> What exactly is the reason behind this?
>

technically a BIOS can opt to give you C states via ACPI on some cpus,
but not on others.

in practice when this happens it tends to be a bug.. but it's
technically a valid configuration



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Arjan van de Ven Intel Open Source Technology Centre
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visit http://www.lesswatts.org
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