From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Muckle Subject: Re: [PATCH 6/8] cpufreq/schedutil: sum per-sched class utilization Date: Wed, 16 Mar 2016 11:20:45 -0700 Message-ID: <56E9A3FD.9050309@linaro.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pf0-f174.google.com ([209.85.192.174]:36822 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934953AbcCPSUq (ORCPT ); Wed, 16 Mar 2016 14:20:46 -0400 Received: by mail-pf0-f174.google.com with SMTP id u190so84510600pfb.3 for ; Wed, 16 Mar 2016 11:20:46 -0700 (PDT) In-Reply-To: <20160316073850.GO6344@twins.programming.kicks-ass.net> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Peter Zijlstra , Michael Turquette 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 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.