From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754122AbaJCPii (ORCPT ); Fri, 3 Oct 2014 11:38:38 -0400 Received: from casper.infradead.org ([85.118.1.10]:34690 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754051AbaJCPia (ORCPT ); Fri, 3 Oct 2014 11:38:30 -0400 Date: Fri, 3 Oct 2014 17:38:26 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, preeti@linux.vnet.ibm.com, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org, riel@redhat.com, Morten.Rasmussen@arm.com, efault@gmx.de, nicolas.pitre@linaro.org, linaro-kernel@lists.linaro.org, daniel.lezcano@linaro.org, dietmar.eggemann@arm.com, pjt@google.com, bsegall@google.com Subject: Re: [PATCH v6 5/6] sched: replace capacity_factor by usage Message-ID: <20141003153826.GM2849@worktop.programming.kicks-ass.net> References: <1411488485-10025-1-git-send-email-vincent.guittot@linaro.org> <1411488485-10025-6-git-send-email-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1411488485-10025-6-git-send-email-vincent.guittot@linaro.org> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 23, 2014 at 06:08:04PM +0200, Vincent Guittot wrote: > This implementation of utilization_avg_contrib doesn't solve the scaling > in-variance problem, so i have to scale the utilization with original > capacity of the CPU in order to get the CPU usage and compare it with the > capacity. Once the scaling invariance will have been added in > utilization_avg_contrib, we will remove the scale of utilization_avg_contrib > by cpu_capacity_orig in get_cpu_usage. But the scaling invariance will come > in another patchset. I would have expected this in the previous patch that introduced that lot. Including a few words on how/why the cpu_capacity is a 'good' approximation etc.. > Finally, the sched_group->sched_group_capacity->capacity_orig has been removed > because it's more used during load balance. That sentence is a contradiction, I expect there's a negative gone missing someplace.