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

To: Jan Beulich <JBeulich@xxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] x86/cpufreq: fix turbo mode detection
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 6 May 2010 16:16:57 +0100
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On 06/05/2010 14:10, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:

> acpi_cpufreq_cpu_init() does generally not run on the CPU the policy
> it deals with is related to, hence using cpuid() directly works only
> as long as all CPUs in the system are identical (which admittedly
> is commonly the case).

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.

> Also fix a minor glitch in xenpm, which I noticed while looking into
> the original inconsistencies on one of my systems.

Would belong in a separate patch. Also it's not clear to me what the
'glitch' is. Printing an asterisk might be frivolous/pointless, but is it

 -- Keir

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