From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuyang Du Subject: Re: [RFC PATCH 06/16] arm: topology: Define TC2 sched energy and provide it to scheduler Date: Sun, 8 Jun 2014 07:53:07 +0800 Message-ID: <20140607235307.GD22261@intel.com> References: <20140604160230.GS29593@e103034-lin> <20140604172712.GJ13930@laptop.programming.kicks-ass.net> <2484761.vkWavnsDx3@vostro.rjw.lan> <20140605065205.GA3213@twins.programming.kicks-ass.net> <539086B3.2010804@gmail.com> <20140605202930.GA15484@intel.com> <20140606080543.GR6758@twins.programming.kicks-ass.net> <20140606003520.GB22261@intel.com> <20140606105036.GQ3213@twins.programming.kicks-ass.net> <20140606121305.GA8571@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140606121305.GA8571@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: Peter Zijlstra , Dirk Brandewie , "Rafael J. Wysocki" , Morten Rasmussen , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "vincent.guittot@linaro.org" , "daniel.lezcano@linaro.org" , "preeti@linux.vnet.ibm.com" , Dietmar Eggemann , len.brown@intel.com, jacob.jun.pan@linux.intel.com List-Id: linux-pm@vger.kernel.org On Fri, Jun 06, 2014 at 02:13:05PM +0200, Ingo Molnar wrote: > > Leakage current typically gets higher with higher frequencies, but > it's also highly process dependent AFAIK. > In general, you can assume leakage power ~ V^2. > If switching power dissipation is the main factor in power use, then > we can essentially assume that P ~ V^2, at the same frequency - and > scales linearly with frequency - but real work performed also scales > semi-linearly with frequency for many workloads, so that's an > invariant for everything except highly memory bound workloads. > Agreed. Strictly, Energy ~ V^2.