From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFCv5 PATCH 30/46] sched: Add cpu capacity awareness to wakeup balancing Date: Thu, 13 Aug 2015 20:24:09 +0200 Message-ID: <20150813182409.GB19282@twins.programming.kicks-ass.net> References: <1436293469-25707-1-git-send-email-morten.rasmussen@arm.com> <1436293469-25707-31-git-send-email-morten.rasmussen@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from casper.infradead.org ([85.118.1.10]:59460 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752637AbbHMSYN (ORCPT ); Thu, 13 Aug 2015 14:24:13 -0400 Content-Disposition: inline In-Reply-To: <1436293469-25707-31-git-send-email-morten.rasmussen@arm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Morten Rasmussen Cc: mingo@redhat.com, vincent.guittot@linaro.org, daniel.lezcano@linaro.org, Dietmar Eggemann , yuyang.du@intel.com, mturquette@baylibre.com, rjw@rjwysocki.net, Juri Lelli , sgurrappadi@nvidia.com, pang.xunlei@zte.com.cn, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org On Tue, Jul 07, 2015 at 07:24:13PM +0100, Morten Rasmussen wrote: > > This patch adds capacity awareness to find_idlest_{group,queue} (used by > SD_BALANCE_{FORK,EXEC}) such that groups/cpus that can accommodate the > waking task based on task utilization are preferred. In addition, wakeup > of existing tasks (SD_BALANCE_WAKE) is sent through > find_idlest_{group,queue} if the task doesn't fit the capacity of the > previous cpu to allow it to escape (override wake_affine) when > necessary instead of relying on periodic/idle/nohz_idle balance to > eventually sort it out. > That's policy not guided by the energy model.. Also we need something clever for the wakeup balancing, the current stuff all stinks :/