From patchwork Thu Oct 5 13:41:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 729910 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 6B2AEE9270E for ; Thu, 5 Oct 2023 15:13:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229461AbjJEPNL (ORCPT ); Thu, 5 Oct 2023 11:13:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233471AbjJEPMP (ORCPT ); Thu, 5 Oct 2023 11:12:15 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6A9C9194; Thu, 5 Oct 2023 06:48:18 -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 7DA30168F; Thu, 5 Oct 2023 06:42:06 -0700 (PDT) Received: from e126645.arm.com (e126645.nice.arm.com [10.34.100.116]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B6CBD3F641; Thu, 5 Oct 2023 06:41:25 -0700 (PDT) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Pierre Gondois , "Rafael J. Wysocki" , Viresh Kumar , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , linux-pm@vger.kernel.org Subject: [PATCH v2] cpufreq: Rebuild sched-domains when removing cpufreq driver Date: Thu, 5 Oct 2023 15:41:20 +0200 Message-Id: <20231005134120.1217829-1-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The Energy Aware Scheduler (EAS) relies on the schedutil governor. When moving to/from the schedutil governor, sched domains must be rebuilt to allow re-evaluating the enablement conditions of EAS. This is done through sched_cpufreq_governor_change(). Having a cpufreq governor assumes a cpufreq driver is running. Inserting/removing a cpufreq driver should trigger a re-evaluation of EAS enablement conditions, avoiding to see EAS enabled when removing a running cpufreq driver. Rebuild the sched domains in schedutil's sugov_init()/sugov_exit(), allowing to check EAS's enablement condition whenever schedutil governor is initialized/exited from. Move relevant code up in schedutil.c to avoid a split and conditional function declaration. Rename sched_cpufreq_governor_change() to sugov_eas_rebuild_sd(). Signed-off-by: Pierre Gondois Acked-by: Viresh Kumar --- drivers/cpufreq/cpufreq.c | 3 +- include/linux/cpufreq.h | 8 ----- kernel/sched/cpufreq_schedutil.c | 55 +++++++++++++++++--------------- 3 files changed, 30 insertions(+), 36 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 60ed89000e82..4bc15634d49c 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1544,7 +1544,7 @@ static int cpufreq_online(unsigned int cpu) /* * Register with the energy model before - * sched_cpufreq_governor_change() is called, which will result + * sugov_eas_rebuild_sd() is called, which will result * in rebuilding of the sched domains, which should only be done * once the energy model is properly initialized for the policy * first. @@ -2652,7 +2652,6 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, ret = cpufreq_start_governor(policy); if (!ret) { pr_debug("governor change\n"); - sched_cpufreq_governor_change(policy, old_gov); return 0; } cpufreq_exit_governor(policy); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 71d186d6933a..1c5ca92a0555 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1193,14 +1193,6 @@ static inline int of_perf_domain_get_sharing_cpumask(int pcpu, const char *list_ } #endif -#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) -void sched_cpufreq_governor_change(struct cpufreq_policy *policy, - struct cpufreq_governor *old_gov); -#else -static inline void sched_cpufreq_governor_change(struct cpufreq_policy *policy, - struct cpufreq_governor *old_gov) { } -#endif - extern unsigned int arch_freq_get_on_cpu(int cpu); #ifndef arch_set_freq_scale diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 4492608b7d7f..901cada51ba7 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -555,6 +555,31 @@ static const struct kobj_type sugov_tunables_ktype = { /********************** cpufreq governor interface *********************/ +#ifdef CONFIG_ENERGY_MODEL +static void rebuild_sd_workfn(struct work_struct *work) +{ + rebuild_sched_domains_energy(); +} + +static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); + +/* + * EAS shouldn't be attempted without sugov, so rebuild the sched_domains + * on governor changes to make sure the scheduler knows about it. + */ +static void sugov_eas_rebuild_sd(void) +{ + /* + * When called from the cpufreq_register_driver() path, the + * cpu_hotplug_lock is already held, so use a work item to + * avoid nested locking in rebuild_sched_domains(). + */ + schedule_work(&rebuild_sd_work); +} +#else +static inline void sugov_eas_rebuild_sd(void) { }; +#endif + struct cpufreq_governor schedutil_gov; static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) @@ -709,6 +734,8 @@ static int sugov_init(struct cpufreq_policy *policy) if (ret) goto fail; + sugov_eas_rebuild_sd(); + out: mutex_unlock(&global_tunables_lock); return 0; @@ -750,6 +777,8 @@ static void sugov_exit(struct cpufreq_policy *policy) sugov_kthread_stop(sg_policy); sugov_policy_free(sg_policy); cpufreq_disable_fast_switch(policy); + + sugov_eas_rebuild_sd(); } static int sugov_start(struct cpufreq_policy *policy) @@ -838,29 +867,3 @@ struct cpufreq_governor *cpufreq_default_governor(void) #endif cpufreq_governor_init(schedutil_gov); - -#ifdef CONFIG_ENERGY_MODEL -static void rebuild_sd_workfn(struct work_struct *work) -{ - rebuild_sched_domains_energy(); -} -static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); - -/* - * EAS shouldn't be attempted without sugov, so rebuild the sched_domains - * on governor changes to make sure the scheduler knows about it. - */ -void sched_cpufreq_governor_change(struct cpufreq_policy *policy, - struct cpufreq_governor *old_gov) -{ - if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) { - /* - * When called from the cpufreq_register_driver() path, the - * cpu_hotplug_lock is already held, so use a work item to - * avoid nested locking in rebuild_sched_domains(). - */ - schedule_work(&rebuild_sd_work); - } - -} -#endif