From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933036Ab3CVBbJ (ORCPT ); Thu, 21 Mar 2013 21:31:09 -0400 Received: from mga11.intel.com ([192.55.52.93]:58414 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932092Ab3CVBbH (ORCPT ); Thu, 21 Mar 2013 21:31:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,888,1355126400"; d="scan'208";a="306691240" Message-ID: <514BB452.2070906@intel.com> Date: Fri, 22 Mar 2013 09:30:58 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130221 Thunderbird/17.0.3 MIME-Version: 1.0 To: Preeti U Murthy CC: mingo@redhat.com, peterz@infradead.org, efault@gmx.de, torvalds@linux-foundation.org, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de, pjt@google.com, namhyung@kernel.org, vincent.guittot@linaro.org, gregkh@linuxfoundation.org, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, morten.rasmussen@arm.com Subject: Re: [patch v5 14/15] sched: power aware load balance References: <1361164062-20111-1-git-send-email-alex.shi@intel.com> <1361164062-20111-15-git-send-email-alex.shi@intel.com> <514941C5.6080007@linux.vnet.ibm.com> <514ABA19.1080807@intel.com> <514AC7B2.7030400@linux.vnet.ibm.com> <514AD26F.9010905@intel.com> <514AE07A.10100@linux.vnet.ibm.com> In-Reply-To: <514AE07A.10100@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/21/2013 06:27 PM, Preeti U Murthy wrote: >> > did you close all of background system services? >> > In theory the rq->avg.runnable_avg_sum should be zero if there is no >> > task a bit long, otherwise there are some bugs in kernel. > Could you explain why rq->avg.runnable_avg_sum should be zero? What if > some kernel thread ran on this run queue and is now finished? Its > utilisation would be say x.How would that ever drop to 0,even if nothing > ran on it later? the value get from decay_load(): sa->runnable_avg_sum = decay_load(sa->runnable_avg_sum, in decay_load it is possible to be set zero. and /proc/sched_debug also approve this: .tg_runnable_contrib : 0 .tg->runnable_avg : 50 .avg->runnable_avg_sum : 0 .avg->runnable_avg_period : 47507 -- Thanks Alex