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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 EB731C4321E for ; Mon, 10 Sep 2018 10:13:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7C5120865 for ; Mon, 10 Sep 2018 10:13:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7C5120865 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 S1728289AbeIJPG7 (ORCPT ); Mon, 10 Sep 2018 11:06:59 -0400 Received: from terminus.zytor.com ([198.137.202.136]:44911 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726738AbeIJPG7 (ORCPT ); Mon, 10 Sep 2018 11:06:59 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w8AADJWD1807810 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 10 Sep 2018 03:13:19 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w8AADJEO1807807; Mon, 10 Sep 2018 03:13:19 -0700 Date: Mon, 10 Sep 2018 03:13:19 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Morten Rasmussen Message-ID: Cc: tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, mingo@kernel.org, peterz@infradead.org, morten.rasmussen@arm.com Reply-To: hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, morten.rasmussen@arm.com, peterz@infradead.org, torvalds@linux-foundation.org, mingo@kernel.org In-Reply-To: <1530699470-29808-2-git-send-email-morten.rasmussen@arm.com> References: <1530699470-29808-2-git-send-email-morten.rasmussen@arm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/topology: Add static_key for asymmetric CPU capacity optimizations Git-Commit-ID: df054e8445a4011e3d693c2268129c0456108663 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: df054e8445a4011e3d693c2268129c0456108663 Gitweb: https://git.kernel.org/tip/df054e8445a4011e3d693c2268129c0456108663 Author: Morten Rasmussen AuthorDate: Wed, 4 Jul 2018 11:17:39 +0100 Committer: Ingo Molnar CommitDate: Mon, 10 Sep 2018 11:05:48 +0200 sched/topology: Add static_key for asymmetric CPU capacity optimizations The existing asymmetric CPU capacity code should cause minimal overhead for others. Putting it behind a static_key, it has been done for SMT optimizations, would make it easier to extend and improve without causing harm to others moving forward. Signed-off-by: Morten Rasmussen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: dietmar.eggemann@arm.com Cc: gaku.inami.xh@renesas.com Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1530699470-29808-2-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 3 +++ kernel/sched/sched.h | 1 + kernel/sched/topology.c | 9 ++++++++- 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f808ddf2a868..3e5071aeb117 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6188,6 +6188,9 @@ static int wake_cap(struct task_struct *p, int cpu, int prev_cpu) { long min_cap, max_cap; + if (!static_branch_unlikely(&sched_asym_cpucapacity)) + return 0; + min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu)); max_cap = cpu_rq(cpu)->rd->max_cpu_capacity; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 4a2e8cae63c4..0f36adc31ba5 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1185,6 +1185,7 @@ DECLARE_PER_CPU(int, sd_llc_id); DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); DECLARE_PER_CPU(struct sched_domain *, sd_numa); DECLARE_PER_CPU(struct sched_domain *, sd_asym); +extern struct static_key_false sched_asym_cpucapacity; struct sched_group_capacity { atomic_t ref; diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 5c4d583d53ee..b0cdf5e95bda 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -398,6 +398,7 @@ DEFINE_PER_CPU(int, sd_llc_id); DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); DEFINE_PER_CPU(struct sched_domain *, sd_numa); DEFINE_PER_CPU(struct sched_domain *, sd_asym); +DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); static void update_top_cache_domain(int cpu) { @@ -1705,6 +1706,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att struct rq *rq = NULL; int i, ret = -ENOMEM; struct sched_domain_topology_level *tl_asym; + bool has_asym = false; alloc_state = __visit_domain_allocation_hell(&d, cpu_map); if (alloc_state != sa_rootdomain) @@ -1720,8 +1722,10 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att for_each_sd_topology(tl) { int dflags = 0; - if (tl == tl_asym) + if (tl == tl_asym) { dflags |= SD_ASYM_CPUCAPACITY; + has_asym = true; + } sd = build_sched_domain(tl, cpu_map, attr, sd, dflags, i); @@ -1773,6 +1777,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att } rcu_read_unlock(); + if (has_asym) + static_branch_enable_cpuslocked(&sched_asym_cpucapacity); + if (rq && sched_debug_enabled) { pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n", cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity);