From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932949Ab3CUHn2 (ORCPT ); Thu, 21 Mar 2013 03:43:28 -0400 Received: from mga02.intel.com ([134.134.136.20]:14408 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756214Ab3CUHn1 (ORCPT ); Thu, 21 Mar 2013 03:43:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,884,1355126400"; d="scan'208";a="282614932" Message-ID: <514ABA19.1080807@intel.com> Date: Thu, 21 Mar 2013 15:43:21 +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: 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> In-Reply-To: <514941C5.6080007@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 03/20/2013 12:57 PM, Preeti U Murthy wrote: > Neither core will be able to pull the task from the other to consolidate > the load because the rq->util of t2 and t4, on which no process is > running, continue to show some number even though they degrade with time > and sgs->utils accounts for them. Therefore, > for core1 and core2, the sgs->utils will be slightly above 100 and the > above condition will fail, thus failing them as candidates for > group_leader,since threshold_util will be 200. Thanks for note, Preeti! Did you find some real issue in some platform? In theory, a totally idle cpu has a zero rq->util at least after 3xxms, and in fact, I find the code works fine on my machines. -- Thanks Alex