From: Juergen Gross <juergen.gross@ts.fujitsu.com>
To: Keir Fraser <keir@xen.org>
Cc: xen-devel@lists.xensource.com
Subject: Re: [PATCH] use per-cpu variables in cpufreq
Date: Fri, 27 May 2011 15:29:17 +0200 [thread overview]
Message-ID: <4DDFA72D.2060806@ts.fujitsu.com> (raw)
In-Reply-To: <CA0561A7.2DB3E%keir@xen.org>
On 05/27/11 15:11, Keir Fraser wrote:
> On 27/05/2011 12:11, "Juergen Gross"<juergen.gross@ts.fujitsu.com> 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
--
Juergen Gross Principal Developer Operating Systems
TSP ES&S SWE OS6 Telephone: +49 (0) 89 3222 2967
Fujitsu Technology Solutions e-mail: juergen.gross@ts.fujitsu.com
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next prev parent reply other threads:[~2011-05-27 13:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-27 11:11 [PATCH] use per-cpu variables in cpufreq Juergen Gross
2011-05-27 13:11 ` Keir Fraser
2011-05-27 13:29 ` Juergen Gross [this message]
2011-05-28 7:52 ` Keir Fraser
2011-05-30 5:47 ` Juergen Gross
2011-05-30 9:45 ` Keir Fraser
2011-05-31 1:51 ` Tian, Kevin
2011-05-31 7:31 ` Keir Fraser
2011-05-31 7:37 ` Liu, Jinsong
2011-05-30 8:06 ` Tian, Kevin
2011-05-30 15:33 ` Liu, Jinsong
2011-06-10 19:00 ` Langsdorf, Mark
2011-06-14 9:04 ` Juergen Gross
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