From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pallipadi, Venkatesh" Subject: Re: [patch 2/2] x86: Manage ENERGY_PERF_BIAS based on cpufreq governor Date: Wed, 03 Mar 2010 09:55:38 -0800 Message-ID: <1267638938.16916.957.camel@localhost.localdomain> References: <20100303000649.757684000@intel.com> <20100303000849.278509000@intel.com> <20100303164007.GA31365@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: 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 In-Reply-To: <20100303164007.GA31365@srcf.ucam.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org 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" 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