From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935209Ab3BTMLO (ORCPT ); Wed, 20 Feb 2013 07:11:14 -0500 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:34768 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934344Ab3BTMLN (ORCPT ); Wed, 20 Feb 2013 07:11:13 -0500 Message-ID: <5124BD07.4050401@linux.vnet.ibm.com> Date: Wed, 20 Feb 2013 17:39:43 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Alex Shi , 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> In-Reply-To: <1361352643.10155.4.camel@laptop> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13022012-5564-0000-0000-000006AFF2B2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? What I mean is,if the answer to the above question is yes,then can we safely assume that the furthur optimizations to the load balancer like the power aware scheduler and the usage of per entity load tracking can be done without considering the real time tasks? Regards Preeti U Murthy >