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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 50A4AC83F3E for ; Tue, 5 Sep 2023 10:05:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HbD3GfN88ZvIDqzpmNa18/3Fx4lxYWmoCSnt9bXlVHU=; b=Z/n6Z0ZgUZKSmF UQt1AgMYPXul/P3psFr9gSFcFjsUjEzsxOjDC2ZreIXR7zmzhn4w13PaVMmCZ/6Yq0dXd7vqKWbEq QqUTYP3x/5vVImGPK+Ct/s0aOqav5SnV10bV8z61MQuuK9/YczuF6Lb4iV7YpQdPyMAnxMx7ETzt/ vLlBGI/+TrccrVnf4tFcf2A4ILWw+eTarTMyGNnhnE+pGKcg9Isk5CTbjmAEaucLF5I21W6ZkEhx+ xEbz8UAOsFP5ftlgiUF/TD5WYPyn8M5TvQ2VVP1qXCgxHzklA7sVUi8GmP3NCUnjQyjMmzFjfNY/M XfHNRS76NZkJDBSVXLQQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qdSwM-005fKc-0q; Tue, 05 Sep 2023 10:05:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qdSwI-005fJw-2v; Tue, 05 Sep 2023 10:05:44 +0000 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 BB74011FB; Tue, 5 Sep 2023 03:06:17 -0700 (PDT) Received: from [10.34.100.102] (e126645.nice.arm.com [10.34.100.102]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D616D3F793; Tue, 5 Sep 2023 03:05:35 -0700 (PDT) Message-ID: Date: Tue, 5 Sep 2023 12:05:30 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH 4/4] energy_model: use a fixed reference frequency Content-Language: en-US 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, 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 Cc: conor.dooley@microchip.com, suagrfillet@gmail.com, ajones@ventanamicro.com, lftan@kernel.org References: <20230901130312.247719-1-vincent.guittot@linaro.org> <20230901130312.247719-5-vincent.guittot@linaro.org> From: Pierre Gondois In-Reply-To: <20230901130312.247719-5-vincent.guittot@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230905_030543_066145_01DA6D5F X-CRM114-Status: GOOD ( 24.87 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Hello Vincent, I tried the patch-set on a platform using cppc_cpufreq and that has boosting frequencies, 1- On such platform, the CPU capacity comes from the CPPC highest_frequency field. The CPU capacity is set to the capacity of the boosting frequency. This behaviour is different from DT platforms where the CPU capacity is updated whenever the boosting mode is enabled (it seems). Wouldn't it be better to have CPU max capacities set to their boosting capacity as for CPPC base platforms ? It seems the max frequency is always available somehow for all the cpufreq drivers with boosting available, i.e. acpi-cpufreq, amd-pstate, cppc_cpufreq. 2- On the CPPC based platforms, the per_cpu freq_factor is not used/updated, meaning that we have: arch_scale_freq_ref_em() \-arch_scale_freq_ref() \-topology_get_freq_ref() \-per_cpu(freq_factor, cpu) (set to the default value: 1) and em_cpu_energy()'s ref_freq variable is then set to 1 instead of the max frequency (leading to a 0 energy computation). 3- Also just in case, arch_scale_freq_ref_policy() and cpufreq_get_hw_max_freq() seem to have close (but not identical) purpose, Regards, Pierre On 9/1/23 15:03, 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) > +{ > + 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 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv