Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935166AbcCPSUs (ORCPT ); Wed, 16 Mar 2016 14:20:48 -0400 Received: from mail-pf0-f173.google.com ([209.85.192.173]:34996 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934994AbcCPSUq (ORCPT ); Wed, 16 Mar 2016 14:20:46 -0400 Subject: Re: [PATCH 6/8] cpufreq/schedutil: sum per-sched class utilization To: Peter Zijlstra , Michael Turquette References: <1457932932-28444-1-git-send-email-mturquette+renesas@baylibre.com> <1457932932-28444-7-git-send-email-mturquette+renesas@baylibre.com> <20160315212926.GG6344@twins.programming.kicks-ass.net> <20160315220951.30639.12872@quark.deferred.io> <20160316073850.GO6344@twins.programming.kicks-ass.net> Cc: rjw@rjwysocki.net, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Juri.Lelli@arm.com, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, vincent.guittot@linaro.org, Michael Turquette From: Steve Muckle X-Enigmail-Draft-Status: N1110 Message-ID: <56E9A3FD.9050309@linaro.org> Date: Wed, 16 Mar 2016 11:20:45 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160316073850.GO6344@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 656 Lines: 14 On 03/16/2016 12:38 AM, Peter Zijlstra wrote: > Somewhere in the giant discussions I mentioned that we should be looking > at a CPPC like interface and pass {min,max} tuples to the cpufreq > selection thingy. > > In that same discussion I also mentioned that we must compute min as the > hard dl reservation, but that for max we can actually use the avg dl + > avg rt + avg cfs. > > That way there is far more room for selecting a sensible frequency. Doesn't the above min/max policy mean that the platform will likely underserve the task load? If avg dl+rt+cfs represents our best estimate of the work to be done, I would think that should be the min.