From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96F8AE7D0A2 for ; Thu, 21 Sep 2023 19:28:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229456AbjIUT2I (ORCPT ); Thu, 21 Sep 2023 15:28:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229743AbjIUT1m (ORCPT ); Thu, 21 Sep 2023 15:27:42 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2DCE2A0C3B; Thu, 21 Sep 2023 10:57:37 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A677D1596; Thu, 21 Sep 2023 03:13:01 -0700 (PDT) Received: from localhost (ionvoi01-desktop.cambridge.arm.com [10.2.78.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 27AD13F59C; Thu, 21 Sep 2023 03:12:24 -0700 (PDT) Date: Thu, 21 Sep 2023 11:12:22 +0100 From: Ionela Voinescu To: Vincent Guittot Cc: linux@armlinux.org.uk, catalin.marinas@arm.com, will@kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, sudeep.holla@arm.com, gregkh@linuxfoundation.org, rafael@kernel.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, viresh.kumar@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-pm@vger.kernel.org, conor.dooley@microchip.com, suagrfillet@gmail.com, ajones@ventanamicro.com, lftan@kernel.org Subject: Re: [PATCH 4/4] energy_model: use a fixed reference frequency Message-ID: References: <20230901130312.247719-1-vincent.guittot@linaro.org> <20230901130312.247719-5-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230901130312.247719-5-vincent.guittot@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Friday 01 Sep 2023 at 15:03:12 (+0200), Vincent Guittot wrote: > The last item of a performance domain is not always the performance point > that has been used to compute CPU's capacity. This can lead to different > target frequency compared with other part of the system like schedutil and > would result in wrong energy estimation. > > a new arch_scale_freq_ref() is available to return a fixed and coherent > frequency reference that can be used when computing the CPU's frequency > for an level of utilization. Use this function when available or fallback > to the last performance domain item otherwise. > > Signed-off-by: Vincent Guittot > --- > include/linux/energy_model.h | 20 +++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > > diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h > index b9caa01dfac4..7ee07be6928e 100644 > --- a/include/linux/energy_model.h > +++ b/include/linux/energy_model.h > @@ -204,6 +204,20 @@ struct em_perf_state *em_pd_get_efficient_state(struct em_perf_domain *pd, > return ps; > } > > +#ifdef arch_scale_freq_ref > +static __always_inline > +unsigned long arch_scale_freq_ref_em(int cpu, struct em_perf_domain *pd) The comments in patch 3/4 should be considered for this function and its use as well. Thanks, Ionela. > +{ > + return arch_scale_freq_ref(cpu); > +} > +#else > +static __always_inline > +unsigned long arch_scale_freq_ref_em(int cpu, struct em_perf_domain *pd) > +{ > + return pd->table[pd->nr_perf_states - 1].frequency; > +} > +#endif > + > /** > * em_cpu_energy() - Estimates the energy consumed by the CPUs of a > * performance domain > @@ -224,7 +238,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, > unsigned long max_util, unsigned long sum_util, > unsigned long allowed_cpu_cap) > { > - unsigned long freq, scale_cpu; > + unsigned long freq, ref_freq, scale_cpu; > struct em_perf_state *ps; > int cpu; > > @@ -241,11 +255,11 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, > */ > cpu = cpumask_first(to_cpumask(pd->cpus)); > scale_cpu = arch_scale_cpu_capacity(cpu); > - ps = &pd->table[pd->nr_perf_states - 1]; > + ref_freq = arch_scale_freq_ref_em(cpu, pd); > > max_util = map_util_perf(max_util); > max_util = min(max_util, allowed_cpu_cap); > - freq = map_util_freq(max_util, ps->frequency, scale_cpu); > + freq = map_util_freq(max_util, ref_freq, scale_cpu); > > /* > * Find the lowest performance state of the Energy Model above the > -- > 2.34.1 > >