Re: [Xen-devel] [PATCH] use per-cpu variables in cpufreq

[Juergen Gross <juergen.gross@xxxxxxxxxxxxxx>]

On 05/27/11 15:11, Keir Fraser wrote:
> On 27/05/2011 12:11, "Juergen Gross"<juergen.gross@xxxxxxxxxxxxxx>  wrote:
>
> > The cpufreq driver used some local arrays indexed by cpu number. This patch
> > replaces those arrays by per-cpu variables. The AMD and INTEL specific parts
> > used different per-cpu data structures with nearly identical semantics.
> > Fold the two structures into one by adding a generic architecture data item.
> Xen's per-cpu data gets freed across cpu offline/online, whereas cpu-indexed
> arrays of course do not. Will the cpufreq state be correctly handled across
> offline/online if we switch to per-cpu vars?
As far as I could see, yes. The data should only be used for cpus with
a valid acpid->cpuid translation, which is created when a cpu is going
online and destroyed when it is going offline again.
It would be nice, however, if the INTEL and/or AMD code owners could
give an ack on this...


Juergen

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