From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933941Ab3GPUcJ (ORCPT ); Tue, 16 Jul 2013 16:32:09 -0400 Received: from mga14.intel.com ([143.182.124.37]:11773 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933879Ab3GPUcI (ORCPT ); Tue, 16 Jul 2013 16:32:08 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,679,1367996400"; d="scan'208";a="269155843" Message-ID: <51E5ADC5.9010105@linux.intel.com> Date: Tue, 16 Jul 2013 13:32:05 -0700 From: Arjan van de Ven User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Peter Zijlstra CC: Morten Rasmussen , mingo@kernel.org, vincent.guittot@linaro.org, preeti@linux.vnet.ibm.com, alex.shi@intel.com, efault@gmx.de, pjt@google.com, len.brown@intel.com, corbet@lwn.net, akpm@linux-foundation.org, torvalds@linux-foundation.org, tglx@linutronix.de, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: Re: [RFC][PATCH 0/9] sched: Power scheduler design proposal References: <51E166C8.3000902@linux.intel.com> <20130715195914.GC23818@dyad.programming.kicks-ass.net> <51E45E8B.705@linux.intel.com> <20130715210650.GF23818@dyad.programming.kicks-ass.net> <20130715211230.GG23818@dyad.programming.kicks-ass.net> <51E47D30.5030203@linux.intel.com> <20130716173848.GA22795@dyad.programming.kicks-ass.net> <51E5947F.4090109@linux.intel.com> <20130716192145.GV17211@twins.programming.kicks-ass.net> <51E5A5AE.7010903@linux.intel.com> <20130716201702.GW17211@twins.programming.kicks-ass.net> In-Reply-To: <20130716201702.GW17211@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/16/2013 1:17 PM, Peter Zijlstra wrote: > On Tue, Jul 16, 2013 at 12:57:34PM -0700, Arjan van de Ven wrote: >> then the question of how much remaining capacity; this is a hard one, and not just >> for Intel. Almost all mobile devices today are thermally constrained, ARM and Intel >> alike (at least the higher performance ones)... the curse of wanting very thin and light >> phones that are made of thermally isolating plastic (so that radio waves can go through) >> and have a nice and bright screen... > > Right, so we might need to track a !idle avg over the thermal domain to > guestimate the head-room and inter-cpu relations. btw one thing to realize is that many of the thermal limits in mobile devices don't have the CPU cores as the primary reason. Other components on the board (screens, modems etc) as well as the GPU likely impact this at least as much as actual cpu usage does. It's usually just that the CPU is the easiest to control down, so that tends to be the first one impacted.