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 3BD7DC83F2C for ; Mon, 4 Sep 2023 12:34:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352799AbjIDMej (ORCPT ); Mon, 4 Sep 2023 08:34:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236987AbjIDMei (ORCPT ); Mon, 4 Sep 2023 08:34:38 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 19BA01A7; Mon, 4 Sep 2023 05:34:33 -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 8B4AB143D; Mon, 4 Sep 2023 05:35:10 -0700 (PDT) Received: from [10.57.93.88] (unknown [10.57.93.88]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A5B373F793; Mon, 4 Sep 2023 05:34:27 -0700 (PDT) Message-ID: <840cb103-8ffb-9798-05a3-a557f78f7f7a@arm.com> Date: Mon, 4 Sep 2023 13:35:05 +0100 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 2/4] topology: add a new arch_scale_freq_reference Content-Language: en-US To: Vincent Guittot Cc: conor.dooley@microchip.com, linux-arm-kernel@lists.infradead.org, suagrfillet@gmail.com, juri.lelli@redhat.com, sudeep.holla@arm.com, palmer@dabbelt.com, linux-riscv@lists.infradead.org, ajones@ventanamicro.com, lftan@kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux@armlinux.org.uk, bristot@redhat.com, catalin.marinas@arm.com, bsegall@google.com, will@kernel.org, vschneid@redhat.com, rostedt@goodmis.org, rafael@kernel.org, dietmar.eggemann@arm.com, aou@eecs.berkeley.edu, mingo@redhat.com, paul.walmsley@sifive.com, mgorman@suse.de, gregkh@linuxfoundation.org, peterz@infradead.org, viresh.kumar@linaro.org References: <20230901130312.247719-1-vincent.guittot@linaro.org> <20230901130312.247719-3-vincent.guittot@linaro.org> From: Lukasz Luba In-Reply-To: <20230901130312.247719-3-vincent.guittot@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi Vincent, On 9/1/23 14:03, Vincent Guittot wrote: > Create a new method to get a unique and fixed max frequency. Currently > cpuinfo.max_freq or last item of performance domain are used as the max > frequency when computing the frequency for a level of utilization but: > - cpuinfo_max_freq can change at runtime. boost is one example of > such change. > - cpuinfo.max_freq and last item of the PD can be different leading to > different results betwen cpufreq and energy model. > > We need to save the max frequency that has been used when computing the > CPUs capacity and use this fixed and coherent value to convert between > frequency and CPU's capacity. > > In fact, we already save the frequency that has been used when computing > the capacity of each CPU. We extend the precision to save khZ instead of > Mhz currently and we modify the type to be aligned with other variables > used when converting frequency to capacity and the other way. I do like this 'kHz' change. We also use kHz in the EM, so better aligned now. > > Signed-off-by: Vincent Guittot > --- > arch/arm/include/asm/topology.h | 1 + > arch/arm64/include/asm/topology.h | 1 + > arch/riscv/include/asm/topology.h | 1 + > drivers/base/arch_topology.c | 9 +++------ > include/linux/arch_topology.h | 7 +++++++ > 5 files changed, 13 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h > index c7d2510e5a78..853c4f81ba4a 100644 > --- a/arch/arm/include/asm/topology.h > +++ b/arch/arm/include/asm/topology.h > @@ -13,6 +13,7 @@ > #define arch_set_freq_scale topology_set_freq_scale > #define arch_scale_freq_capacity topology_get_freq_scale > #define arch_scale_freq_invariant topology_scale_freq_invariant > +#define arch_scale_freq_ref topology_get_freq_ref > #endif > > /* Replace task scheduler's default cpu-invariant accounting */ > diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h > index 9fab663dd2de..a323b109b9c4 100644 > --- a/arch/arm64/include/asm/topology.h > +++ b/arch/arm64/include/asm/topology.h > @@ -23,6 +23,7 @@ void update_freq_counters_refs(void); > #define arch_set_freq_scale topology_set_freq_scale > #define arch_scale_freq_capacity topology_get_freq_scale > #define arch_scale_freq_invariant topology_scale_freq_invariant > +#define arch_scale_freq_ref topology_get_freq_ref > > #ifdef CONFIG_ACPI_CPPC_LIB > #define arch_init_invariance_cppc topology_init_cpu_capacity_cppc > diff --git a/arch/riscv/include/asm/topology.h b/arch/riscv/include/asm/topology.h > index e316ab3b77f3..61183688bdd5 100644 > --- a/arch/riscv/include/asm/topology.h > +++ b/arch/riscv/include/asm/topology.h > @@ -9,6 +9,7 @@ > #define arch_set_freq_scale topology_set_freq_scale > #define arch_scale_freq_capacity topology_get_freq_scale > #define arch_scale_freq_invariant topology_scale_freq_invariant > +#define arch_scale_freq_ref topology_get_freq_ref > > /* Replace task scheduler's default cpu-invariant accounting */ > #define arch_scale_cpu_capacity topology_get_cpu_scale > diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c > index b741b5ba82bd..75fa67477a9d 100644 > --- a/drivers/base/arch_topology.c > +++ b/drivers/base/arch_topology.c > @@ -26,7 +26,7 @@ > static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data); > static struct cpumask scale_freq_counters_mask; > static bool scale_freq_invariant; > -static DEFINE_PER_CPU(u32, freq_factor) = 1; > +DEFINE_PER_CPU(unsigned long, freq_factor) = 1; Why it's not static now? > > static bool supports_scale_freq_counters(const struct cpumask *cpus) > { > @@ -183,10 +183,7 @@ void topology_update_thermal_pressure(const struct cpumask *cpus, > > cpu = cpumask_first(cpus); > max_capacity = arch_scale_cpu_capacity(cpu); > - max_freq = per_cpu(freq_factor, cpu); > - > - /* Convert to MHz scale which is used in 'freq_factor' */ > - capped_freq /= 1000; > + max_freq = arch_scale_freq_ref(cpu); > > /* > * Handle properly the boost frequencies, which should simply clean > @@ -411,7 +408,7 @@ init_cpu_capacity_callback(struct notifier_block *nb, > cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus); > > for_each_cpu(cpu, policy->related_cpus) > - per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq / 1000; > + per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq; > > if (cpumask_empty(cpus_to_visit)) { > topology_normalize_cpu_scale(); > diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h > index a07b510e7dc5..7a2dba9c3dc0 100644 > --- a/include/linux/arch_topology.h > +++ b/include/linux/arch_topology.h > @@ -27,6 +27,13 @@ static inline unsigned long topology_get_cpu_scale(int cpu) > > void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity); > > +DECLARE_PER_CPU(unsigned long, freq_factor); > + > +static inline unsigned long topology_get_freq_ref(int cpu) > +{ > + return per_cpu(freq_factor, cpu); > +} > + > DECLARE_PER_CPU(unsigned long, arch_freq_scale); > > static inline unsigned long topology_get_freq_scale(int cpu) Apart from that 'static' missing, that looks good. Regards, Lukasz