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=-11.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 34A6FC07E85 for ; Tue, 11 Dec 2018 15:37:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC16020672 for ; Tue, 11 Dec 2018 15:37:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC16020672 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727176AbeLKPhG (ORCPT ); Tue, 11 Dec 2018 10:37:06 -0500 Received: from terminus.zytor.com ([198.137.202.136]:47163 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726448AbeLKPhG (ORCPT ); Tue, 11 Dec 2018 10:37:06 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id wBBFae6j4043181 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 11 Dec 2018 07:36:40 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id wBBFaerY4043178; Tue, 11 Dec 2018 07:36:40 -0800 Date: Tue, 11 Dec 2018 07:36:40 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Quentin Perret Message-ID: Cc: tglx@linutronix.de, hpa@zytor.com, quentin.perret@arm.com, torvalds@linux-foundation.org, efault@gmx.de, mingo@kernel.org, linux-kernel@vger.kernel.org, peterz@infradead.org Reply-To: torvalds@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, quentin.perret@arm.com, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, efault@gmx.de In-Reply-To: <20181203095628.11858-10-quentin.perret@arm.com> References: <20181203095628.11858-10-quentin.perret@arm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/toplogy: Introduce the 'sched_energy_present' static key Git-Commit-ID: 1f74de8798c93ce14801cc4e772603e51c841c33 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 1f74de8798c93ce14801cc4e772603e51c841c33 Gitweb: https://git.kernel.org/tip/1f74de8798c93ce14801cc4e772603e51c841c33 Author: Quentin Perret AuthorDate: Mon, 3 Dec 2018 09:56:22 +0000 Committer: Ingo Molnar CommitDate: Tue, 11 Dec 2018 15:17:01 +0100 sched/toplogy: Introduce the 'sched_energy_present' static key In order to make sure Energy Aware Scheduling (EAS) will not impact systems where no Energy Model is available, introduce a static key guarding the access to EAS code. Since EAS is enabled on a per-root-domain basis, the static key is enabled when at least one root domain meets all conditions for EAS. Signed-off-by: Quentin Perret Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: adharmap@codeaurora.org Cc: chris.redpath@arm.com Cc: currojerez@riseup.net Cc: dietmar.eggemann@arm.com Cc: edubezval@gmail.com Cc: gregkh@linuxfoundation.org Cc: javi.merino@kernel.org Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: pkondeti@codeaurora.org Cc: rjw@rjwysocki.net Cc: skannan@codeaurora.org Cc: smuckle@google.com Cc: srinivas.pandruvada@linux.intel.com Cc: thara.gopinath@linaro.org Cc: tkjos@google.com Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Cc: viresh.kumar@linaro.org Link: https://lkml.kernel.org/r/20181203095628.11858-10-quentin.perret@arm.com Signed-off-by: Ingo Molnar --- kernel/sched/sched.h | 4 ++++ kernel/sched/topology.c | 28 ++++++++++++++++++++++++---- 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index fd84900b0b21..2b3cf356e958 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2296,3 +2296,7 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned #else #define perf_domain_span(pd) NULL #endif + +#ifdef CONFIG_SMP +extern struct static_key_false sched_energy_present; +#endif diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 0a5a1d3a4eae..3f35ba1d8fde 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -201,6 +201,7 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) return 1; } +DEFINE_STATIC_KEY_FALSE(sched_energy_present); #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) DEFINE_MUTEX(sched_energy_mutex); bool sched_energy_update; @@ -273,6 +274,19 @@ static void destroy_perf_domain_rcu(struct rcu_head *rp) free_pd(pd); } +static void sched_energy_set(bool has_eas) +{ + if (!has_eas && static_branch_unlikely(&sched_energy_present)) { + if (sched_debug()) + pr_info("%s: stopping EAS\n", __func__); + static_branch_disable_cpuslocked(&sched_energy_present); + } else if (has_eas && !static_branch_unlikely(&sched_energy_present)) { + if (sched_debug()) + pr_info("%s: starting EAS\n", __func__); + static_branch_enable_cpuslocked(&sched_energy_present); + } +} + /* * EAS can be used on a root domain if it meets all the following conditions: * 1. an Energy Model (EM) is available; @@ -299,7 +313,7 @@ static void destroy_perf_domain_rcu(struct rcu_head *rp) #define EM_MAX_COMPLEXITY 2048 extern struct cpufreq_governor schedutil_gov; -static void build_perf_domains(const struct cpumask *cpu_map) +static bool build_perf_domains(const struct cpumask *cpu_map) { int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map); struct perf_domain *pd = NULL, *tmp; @@ -365,7 +379,7 @@ static void build_perf_domains(const struct cpumask *cpu_map) if (tmp) call_rcu(&tmp->rcu, destroy_perf_domain_rcu); - return; + return !!pd; free: free_pd(pd); @@ -373,6 +387,8 @@ free: rcu_assign_pointer(rd->pd, NULL); if (tmp) call_rcu(&tmp->rcu, destroy_perf_domain_rcu); + + return false; } #else static void free_pd(struct perf_domain *pd) { } @@ -2114,6 +2130,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], struct sched_domain_attr *dattr_new) { + bool __maybe_unused has_eas = false; int i, j, n; int new_topology; @@ -2177,14 +2194,17 @@ match2: for (i = 0; i < ndoms_new; i++) { for (j = 0; j < n && !sched_energy_update; j++) { if (cpumask_equal(doms_new[i], doms_cur[j]) && - cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) + cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) { + has_eas = true; goto match3; + } } /* No match - add perf. domains for a new rd */ - build_perf_domains(doms_new[i]); + has_eas |= build_perf_domains(doms_new[i]); match3: ; } + sched_energy_set(has_eas); #endif /* Remember the new sched domains: */