From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934323Ab3BTOhC (ORCPT ); Wed, 20 Feb 2013 09:37:02 -0500 Received: from mga11.intel.com ([192.55.52.93]:12725 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933182Ab3BTOhB (ORCPT ); Wed, 20 Feb 2013 09:37:01 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,702,1355126400"; d="scan'208";a="293602977" Message-ID: <5124DF88.5050908@intel.com> Date: Wed, 20 Feb 2013 22:36:56 +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: Preeti U Murthy , 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, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, morten.rasmussen@arm.com Subject: Re: [patch v5 06/15] sched: log the cpu utilization at rq References: <1361164062-20111-1-git-send-email-alex.shi@intel.com> <1361164062-20111-7-git-send-email-alex.shi@intel.com> <1361352643.10155.4.camel@laptop> <5124BD07.4050401@linux.vnet.ibm.com> <1361367264.10155.31.camel@laptop> In-Reply-To: <1361367264.10155.31.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 02/20/2013 09:34 PM, Peter Zijlstra wrote: > On Wed, 2013-02-20 at 17:39 +0530, Preeti U Murthy wrote: >> Hi, >> >>>> /* >>>> * This is the main, per-CPU runqueue data structure. >>>> * >>>> @@ -481,6 +484,7 @@ struct rq { >>>> #endif >>>> >>>> struct sched_avg avg; >>>> + unsigned int util; >>>> }; >>>> >>>> static inline int cpu_of(struct rq *rq) >>> >>> You don't actually compute the rq utilization, you only compute the >>> utilization as per the fair class, so if there's significant RT activity >>> it'll think the cpu is under-utilized, whihc I think will result in the >>> wrong thing. >> >> Correct me if I am wrong,but isn't the current load balancer also >> disregarding the real time tasks to calculate the domain/group/cpu level >> load too? > > Nope, the rt utilization affects the cpu_power, thereby correcting the > weight stuff. The balance policy use group capacity, that implicated using cpu power, but seems capacity is a very rough data. > > -- Thanks Alex