From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754603AbbCXQCL (ORCPT ); Tue, 24 Mar 2015 12:02:11 -0400 Received: from casper.infradead.org ([85.118.1.10]:36453 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754588AbbCXQCI (ORCPT ); Tue, 24 Mar 2015 12:02:08 -0400 Date: Tue, 24 Mar 2015 17:01:55 +0100 From: Peter Zijlstra To: Morten Rasmussen Cc: mingo@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, yuyang.du@intel.com, preeti@linux.vnet.ibm.com, mturquette@linaro.org, nico@linaro.org, rjw@rjwysocki.net, juri.lelli@arm.com, linux-kernel@vger.kernel.org Subject: Re: [RFCv3 PATCH 46/48] sched: Turn off fast idling of cpus on a partially loaded system Message-ID: <20150324160155.GV23123@twins.programming.kicks-ass.net> References: <1423074685-6336-1-git-send-email-morten.rasmussen@arm.com> <1423074685-6336-47-git-send-email-morten.rasmussen@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1423074685-6336-47-git-send-email-morten.rasmussen@arm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 04, 2015 at 06:31:23PM +0000, Morten Rasmussen wrote: > From: Dietmar Eggemann > > We do not want to miss out on the ability to do energy-aware idle load > balancing if the system is only partially loaded since the operational > range of energy-aware scheduling corresponds to a partially loaded > system. We might want to pull a single remaining task from a potential > src cpu towards an idle destination cpu if the energy model tells us > this is worth doing to save energy. Should this not pair with a change to need_active_balance() ?