From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757614Ab3BNDKd (ORCPT ); Wed, 13 Feb 2013 22:10:33 -0500 Received: from mga02.intel.com ([134.134.136.20]:48587 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753935Ab3BNDK3 (ORCPT ); Wed, 13 Feb 2013 22:10:29 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,660,1355126400"; d="scan'208";a="285500482" Message-ID: <511C559F.4090800@intel.com> Date: Thu, 14 Feb 2013 11:10:23 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120912 Thunderbird/15.0.1 MIME-Version: 1.0 To: Peter Zijlstra CC: torvalds@linux-foundation.org, mingo@redhat.com, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de, pjt@google.com, namhyung@kernel.org, efault@gmx.de, vincent.guittot@linaro.org, gregkh@linuxfoundation.org, preeti@linux.vnet.ibm.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [patch v4 11/18] sched: log the cpu utilization at rq References: <1358996820-23036-1-git-send-email-alex.shi@intel.com> <1358996820-23036-12-git-send-email-alex.shi@intel.com> <1360665592.4485.26.camel@laptop> In-Reply-To: <1360665592.4485.26.camel@laptop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/12/2013 06:39 PM, Peter Zijlstra wrote: > On Thu, 2013-01-24 at 11:06 +0800, Alex Shi wrote: >> >> The cpu's utilization is to measure how busy is the cpu. >> util = cpu_rq(cpu)->avg.runnable_avg_sum >> / cpu_rq(cpu)->avg.runnable_avg_period; >> >> Since the util is no more than 1, we use its percentage value in later >> caculations. And set the the FULL_UTIL as 100%. >> >> In later power aware scheduling, we are sensitive for how busy of the >> cpu, not how much weight of its load. As to power consuming, it is more >> related with cpu busy time, not the load weight. > > I think we can make that argument in general; that is irrespective of > the actual policy. We simply never had anything better to go with. > > So please clarify why you think this only applies to power aware > scheduling. Um, the rq->util is a general argument. It can be used on any other places if needed, not power aware scheduling specific. > -- Thanks Alex