Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752741AbaFGCwx (ORCPT ); Fri, 6 Jun 2014 22:52:53 -0400 Received: from mail-qa0-f52.google.com ([209.85.216.52]:47511 "EHLO mail-qa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752563AbaFGCwv (ORCPT ); Fri, 6 Jun 2014 22:52:51 -0400 Date: Fri, 6 Jun 2014 22:52:49 -0400 (EDT) From: Nicolas Pitre To: Peter Zijlstra cc: Morten Rasmussen , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "mingo@kernel.org" , "rjw@rjwysocki.net" , "vincent.guittot@linaro.org" , "daniel.lezcano@linaro.org" , "preeti@linux.vnet.ibm.com" , Dietmar Eggemann Subject: Re: [RFC PATCH 06/16] arm: topology: Define TC2 sched energy and provide it to scheduler In-Reply-To: <20140604172712.GJ13930@laptop.programming.kicks-ass.net> Message-ID: References: <1400869003-27769-1-git-send-email-morten.rasmussen@arm.com> <1400869003-27769-7-git-send-email-morten.rasmussen@arm.com> <20140603115015.GZ11096@twins.programming.kicks-ass.net> <20140604160230.GS29593@e103034-lin> <20140604172712.GJ13930@laptop.programming.kicks-ass.net> User-Agent: Alpine 2.11 (LFD 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Jun 2014, Peter Zijlstra wrote: > On Wed, Jun 04, 2014 at 05:02:30PM +0100, Morten Rasmussen wrote: > > On Tue, Jun 03, 2014 at 12:50:15PM +0100, Peter Zijlstra wrote: > > > On Fri, May 23, 2014 at 07:16:33PM +0100, Morten Rasmussen wrote: > > > > +static struct capacity_state cap_states_cluster_a7[] = { > > > > + /* Cluster only power */ > > > > + { .cap = 358, .power = 2967, }, /* 350 MHz */ > > > > + { .cap = 410, .power = 2792, }, /* 400 MHz */ > > > > + { .cap = 512, .power = 2810, }, /* 500 MHz */ > > > > + { .cap = 614, .power = 2815, }, /* 600 MHz */ > > > > + { .cap = 717, .power = 2919, }, /* 700 MHz */ > > > > + { .cap = 819, .power = 2847, }, /* 800 MHz */ > > > > + { .cap = 922, .power = 3917, }, /* 900 MHz */ > > > > + { .cap = 1024, .power = 4905, }, /* 1000 MHz */ > > > > + }; > > > > > > So one thing I remember was that we spoke about restricting this to > > > frequency levels where the voltage changed. > > > > > > Because voltage jumps were the biggest factor to energy usage. > > > > > > Any word on that? > > > > Since we don't drive P-state changes from the scheduler, I think we > > could leave out P-states from the table without too much trouble. Good > > point. > > Well, we eventually want to go there I think. People within Linaro have initial code for this. Should be posted as an RFC soon. > Although we still needed > to come up with something for Intel, because I'm not at all sure how all > that works. Our initial code reuse whatever existing platform specific cpufreq drivers. The idea is to bypass the cpufreq governors. If Intel hardware doesn't provide/allow much control here then the platform driver should already tell the cpufreq core (and by extension the scheduler) about the extent of what can be done. Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/