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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBE51C5DF60 for ; Thu, 7 Nov 2019 13:00:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9EB442178F for ; Thu, 7 Nov 2019 13:00:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388729AbfKGNAa (ORCPT ); Thu, 7 Nov 2019 08:00:30 -0500 Received: from foss.arm.com ([217.140.110.172]:55734 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726873AbfKGNAa (ORCPT ); Thu, 7 Nov 2019 08:00:30 -0500 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 865C331B; Thu, 7 Nov 2019 05:00:29 -0800 (PST) Received: from [192.168.0.9] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B1BAE3F6C4; Thu, 7 Nov 2019 05:00:27 -0800 (PST) Subject: Re: [Patch v5 5/6] thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping From: Dietmar Eggemann To: Thara Gopinath , mingo@redhat.com, peterz@infradead.org, ionela.voinescu@arm.com, vincent.guittot@linaro.org, rui.zhang@intel.com, edubezval@gmail.com, qperret@google.com Cc: linux-kernel@vger.kernel.org, amit.kachhap@gmail.com, javi.merino@kernel.org, daniel.lezcano@linaro.org References: <1572979786-20361-1-git-send-email-thara.gopinath@linaro.org> <1572979786-20361-6-git-send-email-thara.gopinath@linaro.org> <05c53b6f-fd16-3e8b-e8da-ea56325cec33@arm.com> Message-ID: Date: Thu, 7 Nov 2019 14:00:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <05c53b6f-fd16-3e8b-e8da-ea56325cec33@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/11/2019 13:50, Dietmar Eggemann wrote: > On 05/11/2019 19:49, Thara Gopinath wrote: > > [...] > >> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c >> index 391f397..c65b7c4 100644 >> --- a/drivers/thermal/cpu_cooling.c >> +++ b/drivers/thermal/cpu_cooling.c >> @@ -218,6 +218,27 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, >> } >> >> /** >> + * update_sched_max_capacity - update scheduler about change in cpu >> + * max frequency. >> + * @cpus: list of cpus whose max capacity needs udating in scheduler. >> + * @cur_max_freq: current maximum frequency. >> + * @max_freq: highest possible frequency. >> + */ >> +static void update_sched_max_capacity(struct cpumask *cpus, >> + unsigned int cur_max_freq, >> + unsigned int max_freq) >> +{ >> + int cpu; >> + unsigned long capacity; >> + >> + for_each_cpu(cpu, cpus) { >> + capacity = cur_max_freq * arch_scale_cpu_capacity(cpu); >> + capacity /= max_freq; >> + update_thermal_pressure(cpu, capacity); >> + } >> +} >> + >> +/** > > Have you seen > https://lore.kernel.org/r/2b19d7da-412c-932f-7251-110eadbef3e3@arm.com ? > > Also the naming 'update_thermal_pressure()' is not really suitable for > an external task scheduler interface. If I see this called in the > cooling device code, I wouldn't guess that this is a task scheduler > interface. > > [...] The current interface to bring in frequency and uarch (CPU) invariance information into the task scheduler is arch_scale_[freq|cpu]_capacity. So why not follow this approach for the thermal->sched interface? +#ifndef arch_scale_thermal_capacity +static __always_inline +unsigned long arch_scale_thermal_capacity(int cpu) +{ + return 0; +} +#endif Leave per_cpu(thermal_pressure, cpu) within cpu cooling and let cpu cooling (or even platform) #define arch_scale_thermal_capacity.