From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755435Ab0CCRzn (ORCPT ); Wed, 3 Mar 2010 12:55:43 -0500 Received: from mga14.intel.com ([143.182.124.37]:58104 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755406Ab0CCRzk (ORCPT ); Wed, 3 Mar 2010 12:55:40 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,574,1262592000"; d="scan'208";a="250432232" Subject: Re: [patch 2/2] x86: Manage ENERGY_PERF_BIAS based on cpufreq governor From: "Pallipadi, Venkatesh" To: Matthew Garrett Cc: Ingo Molnar , H Peter Anvin , Thomas Gleixner , Len Brown , Dave Jones , "linux-kernel@vger.kernel.org" , "linux-acpi@vger.kernel.org" In-Reply-To: <20100303164007.GA31365@srcf.ucam.org> References: <20100303000649.757684000@intel.com> <20100303000849.278509000@intel.com> <20100303164007.GA31365@srcf.ucam.org> Content-Type: text/plain Date: Wed, 03 Mar 2010 09:55:38 -0800 Message-Id: <1267638938.16916.957.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 (2.24.3-1.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-03-03 at 08:40 -0800, Matthew Garrett wrote: > Have you done any measurements with this bit being set dynamically by > ondemand depending on the target frequency? > The not so good part about this feature is that its setting is opaque. Different CPUs can use this value for different optimizations. So, in future we may have to change the value of this MSR based on frequency or other metrics. But, for CPUs which support this MSR today, changing the value with frequency do not make any difference. Thanks, Venki