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 DE911C0032E for ; Wed, 25 Oct 2023 20:13:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229498AbjJYUNX (ORCPT ); Wed, 25 Oct 2023 16:13:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjJYUNW (ORCPT ); Wed, 25 Oct 2023 16:13:22 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 975BEDC; Wed, 25 Oct 2023 13:13:19 -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 E9CF62F4; Wed, 25 Oct 2023 13:14:00 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C9A543F738; Wed, 25 Oct 2023 13:13:13 -0700 (PDT) Message-ID: Date: Wed, 25 Oct 2023 22:13:12 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency To: Vincent Guittot , 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, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, viresh.kumar@linaro.org, lenb@kernel.org, robert.moore@intel.com, lukasz.luba@arm.com, ionela.voinescu@arm.com, pierre.gondois@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org, acpica-devel@lists.linuxfoundation.org Cc: conor.dooley@microchip.com, suagrfillet@gmail.com, ajones@ventanamicro.com, lftan@kernel.org References: <20231018162540.667646-1-vincent.guittot@linaro.org> <20231018162540.667646-4-vincent.guittot@linaro.org> Content-Language: en-US From: Dietmar Eggemann In-Reply-To: <20231018162540.667646-4-vincent.guittot@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 18/10/2023 18:25, Vincent Guittot wrote: > cpuinfo.max_freq can change at runtime because of boost as an example. This > implies that the value could be different than the one that has been > used when computing the capacity of a CPU. > > The new arch_scale_freq_ref() returns a fixed and coherent reference > frequency that can be used when computing a frequency based on utilization. > > Use this arch_scale_freq_ref() when available and fallback to > policy otherwise. > > Signed-off-by: Vincent Guittot > Reviewed-by: Lukasz Luba > Tested-by: Lukasz Luba > > --- > kernel/sched/cpufreq_schedutil.c | 26 ++++++++++++++++++++++++-- > 1 file changed, 24 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c > index 458d359f5991..6e4030482ae8 100644 > --- a/kernel/sched/cpufreq_schedutil.c > +++ b/kernel/sched/cpufreq_schedutil.c > @@ -114,6 +114,28 @@ static void sugov_deferred_update(struct sugov_policy *sg_policy) > } > } > > +/** > + * cpufreq_get_capacity_ref_freq - get the reference frequency of a given CPU that s/cpufreq_get_capacity_ref_freq/get_capacity_ref_freq s/of a given CPU/for a given cpufreq policy ? (of which the CPU managing it is used for the arch_scale_freq_ref() call in the function. > + * has been used to correlate frequency and compute capacity. > + * @policy: the cpufreq policy of the CPU in question. > + * @use_current: Fallback to current freq instead of policy->cpuinfo.max_freq. Looks like use_current does not exists as a parameter. > + * > + * Return: the reference CPU frequency to compute a capacity. > + */ > +static __always_inline > +unsigned long get_capacity_ref_freq(struct cpufreq_policy *policy) > +{ > + unsigned int freq = arch_scale_freq_ref(policy->cpu); > + > + if (freq) > + return freq; > + > + if (arch_scale_freq_invariant()) > + return policy->cpuinfo.max_freq; > + > + return policy->cur; > +} Reviewed-by: Dietmar Eggemann