Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934786AbcCPRgN (ORCPT ); Wed, 16 Mar 2016 13:36:13 -0400 Received: from casper.infradead.org ([85.118.1.10]:36782 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932322AbcCPRgL (ORCPT ); Wed, 16 Mar 2016 13:36:11 -0400 Date: Wed, 16 Mar 2016 18:35:41 +0100 From: Peter Zijlstra To: "Rafael J. Wysocki" Cc: Linux PM list , Juri Lelli , Steve Muckle , ACPI Devel Maling List , Linux Kernel Mailing List , Srinivas Pandruvada , Viresh Kumar , Vincent Guittot , Michael Turquette , Ingo Molnar Subject: Re: [PATCH v4 7/7] cpufreq: schedutil: New governor based on scheduler utilization data Message-ID: <20160316173541.GD6344@twins.programming.kicks-ass.net> References: <1711281.bPmSjlBT7c@vostro.rjw.lan> <11678919.CQLTrQTYxG@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <11678919.CQLTrQTYxG@vostro.rjw.lan> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1497 Lines: 52 On Wed, Mar 16, 2016 at 03:59:18PM +0100, Rafael J. Wysocki wrote: > +static unsigned int get_next_freq(struct cpufreq_policy *policy, > + unsigned long util, unsigned long max) > +{ > + unsigned int freq = arch_scale_freq_invariant() ? > + policy->cpuinfo.max_freq : policy->cur; > + > + return (freq + (freq >> 2)) * util / max; > +} > + > +static void sugov_update_single(struct update_util_data *hook, u64 time, > + unsigned long util, unsigned long max) > +{ > + struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); > + struct sugov_policy *sg_policy = sg_cpu->sg_policy; > + struct cpufreq_policy *policy = sg_policy->policy; > + unsigned int next_f; > + > + if (!sugov_should_update_freq(sg_policy, time)) > + return; > + > + next_f = util <= max ? > + get_next_freq(policy, util, max) : policy->cpuinfo.max_freq; I'm not sure that is correct, would not something like this be more accurate? if (util > max) util = max; next_f = get_next_freq(policy, util, max); After all, if we clip util we will still only increment to the next freq with our multiplication factor. Hmm, or was this meant to deal with the DL/RT stuff? Would then not something like: /* ULONG_MAX is used to force max_freq for Real-Time policies */ if (util == ULONG_MAX) { next_f = policy->cpuinfo.max_freq; } else { if (util > max) util = max; next_f = get_next_freq(policy, util, max); } Be clearer? > + sugov_update_commit(sg_policy, time, next_f); > +}