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Re: [Xen-devel] [PATCH] x86/cpufreq: fix turbo mode detection

To: Jan Beulich <JBeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] x86/cpufreq: fix turbo mode detection
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 6 May 2010 17:46:59 +0100
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On 06/05/2010 16:25, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:

>> Doesn't the fact that acpi_cpufreq_driver.getavg is a single global function
>> pointer defeat the object of this patch? The effect of proper localised
>> checking of cpuid_ecx(6) is still global.
>> The check of cpuid_eax(6) yields a localised effect (on policy->turbo, where
>> policy does appear to be per-cpu). But whether 'fixing' that but not
>> properly the other is worthwhile, I'm not sure.
> Yes, only one of the two were really an issue, but since I needed
> to move part of this code around, I decided to move it all at once
> in case later other bits (with non-global) meaning would get used.

Yeah, but do cpuid_ecx(6) cross-cpu differences really not matter, or is it
just that it has global effect so there was nothing more you could (easily)
do? I mean, if that latter then the solution is really half-baked isn't it.
And is half-baked worth doing?

 -- Keir

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