From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933016Ab3BLKj4 (ORCPT ); Tue, 12 Feb 2013 05:39:56 -0500 Received: from merlin.infradead.org ([205.233.59.134]:39104 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932696Ab3BLKjz (ORCPT ); Tue, 12 Feb 2013 05:39:55 -0500 Message-ID: <1360665592.4485.26.camel@laptop> Subject: Re: [patch v4 11/18] sched: log the cpu utilization at rq From: Peter Zijlstra To: Alex Shi 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 Date: Tue, 12 Feb 2013 11:39:52 +0100 In-Reply-To: <1358996820-23036-12-git-send-email-alex.shi@intel.com> References: <1358996820-23036-1-git-send-email-alex.shi@intel.com> <1358996820-23036-12-git-send-email-alex.shi@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.