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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 DEBA2C3A59E for ; Mon, 26 Aug 2019 09:51:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB5852070B for ; Mon, 26 Aug 2019 09:51:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730151AbfHZJvV (ORCPT ); Mon, 26 Aug 2019 05:51:21 -0400 Received: from foss.arm.com ([217.140.110.172]:55484 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726616AbfHZJvV (ORCPT ); Mon, 26 Aug 2019 05:51:21 -0400 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 2DF0715AD; Mon, 26 Aug 2019 02:51:20 -0700 (PDT) Received: from [192.168.0.9] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D3CF3F59C; Mon, 26 Aug 2019 02:51:18 -0700 (PDT) Subject: Re: [PATCH] sched/cpufreq: Align trace event behavior of fast switching To: Peter Zijlstra , "Rafael J. Wysocki" Cc: Douglas RAILLARD , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, viresh.kumar@linaro.org, mingo@redhat.com References: <20190807153340.11516-1-douglas.raillard@arm.com> <3316959.EEulJYEQYJ@kreacher> <20190826094058.GP2369@hirez.programming.kicks-ass.net> From: Dietmar Eggemann Message-ID: Date: Mon, 26 Aug 2019 11:51:17 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190826094058.GP2369@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 26/08/2019 11:40, Peter Zijlstra wrote: > On Mon, Aug 26, 2019 at 11:10:52AM +0200, Rafael J. Wysocki wrote: >> On Wednesday, August 7, 2019 5:33:40 PM CEST Douglas RAILLARD wrote: >>> Fast switching path only emits an event for the CPU of interest, whereas the >>> regular path emits an event for all the CPUs that had their frequency changed, >>> i.e. all the CPUs sharing the same policy. >>> >>> With the current behavior, looking at cpu_frequency event for a given CPU that >>> is using the fast switching path will not give the correct frequency signal. >>> >>> Signed-off-by: Douglas RAILLARD >>> --- >>> kernel/sched/cpufreq_schedutil.c | 7 ++++++- >>> 1 file changed, 6 insertions(+), 1 deletion(-) >>> >>> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c >>> index 1f82ab108bab..975ccc3de807 100644 >>> --- a/kernel/sched/cpufreq_schedutil.c >>> +++ b/kernel/sched/cpufreq_schedutil.c >>> @@ -153,6 +153,7 @@ static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time, >>> unsigned int next_freq) >>> { >>> struct cpufreq_policy *policy = sg_policy->policy; >>> + int cpu; >>> >>> if (!sugov_update_next_freq(sg_policy, time, next_freq)) >>> return; >>> @@ -162,7 +163,11 @@ static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time, >>> return; >>> >>> policy->cur = next_freq; >>> - trace_cpu_frequency(next_freq, smp_processor_id()); >>> + >>> + if (trace_cpu_frequency_enabled()) { >>> + for_each_cpu(cpu, policy->cpus) >>> + trace_cpu_frequency(next_freq, cpu); >>> + } >>> } >>> >>> static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time, >>> >> >> Peter, any comments here? > > I was thinking this would be a static map and dealing with it would be > something trivially done in post (or manually while reading), but sure, > whatever: > > Acked-by: Peter Zijlstra (Intel) I think our EAS tooling expects the behavior of the non-fast-switching driver (cpufreq.c cpufreq_notify_transition() CPUFREQ_POSTCHANGE). Pixel 3 is the first device with a fast-switching driver we test on. Not sure about the extra 'if trace_cpu_frequency_enabled()' but I guess it doesn't hurt.