From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934649Ab3E1Pwv (ORCPT ); Tue, 28 May 2013 11:52:51 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:47334 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934614Ab3E1Pwt (ORCPT ); Tue, 28 May 2013 11:52:49 -0400 Message-ID: <51A4D2CE.90604@intel.com> Date: Tue, 28 May 2013 08:52:46 -0700 From: Dirk Brandewie User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: =?UTF-8?B?SsO2cmcgT3R0ZQ==?= CC: Linux Kernel Mailing List , rafael.j.wysocki@intel.com Subject: Re: [v3.10-rc] intel_pstate question References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jörg, On 05/28/2013 08:02 AM, Jörg Otte wrote: > Hi, > > the sysfs-interface of intel_pstate is different to that of the acpi driver: > - intel_pstate shows current cpu-frequency in "cpuinfo_cur_freq" whereas > the acpi counterpart uses "scaling_cur_freq". > - moreover cpuinfo_cur_freq is readable by root only, whereas > scaling_cur_freq is world readable. > > A monitoring tool must take care of theese differences. > Is this intentional? > This is a side effect of the interface that intel_pstate presents to the cpufreq core. cpuinfo_cur_freq reports the value returned from the scaling driver. scaling_cur_freq reports the current frequency in the governors policy structure. intel_pstate has an internal governor so the core does not try to interpret the policy structure. I don't know why cpuinfo_cur_info is read-only root maybe Rafael knows the history. > Thanks, Jörg > > Please CC me in answeres, I'm not subscribed. >