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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 CEF41C4338F for ; Mon, 26 Jul 2021 10:24:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1E44608FB for ; Mon, 26 Jul 2021 10:24:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232815AbhGZJng (ORCPT ); Mon, 26 Jul 2021 05:43:36 -0400 Received: from outbound-smtp38.blacknight.com ([46.22.139.221]:56849 "EHLO outbound-smtp38.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232619AbhGZJnc (ORCPT ); Mon, 26 Jul 2021 05:43:32 -0400 Received: from mail.blacknight.com (pemlinmail06.blacknight.ie [81.17.255.152]) by outbound-smtp38.blacknight.com (Postfix) with ESMTPS id 4C2331A1B for ; Mon, 26 Jul 2021 11:24:00 +0100 (IST) Received: (qmail 23587 invoked from network); 26 Jul 2021 10:24:00 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.17.255]) by 81.17.254.9 with ESMTPA; 26 Jul 2021 10:23:59 -0000 From: Mel Gorman To: LKML Cc: Ingo Molnar , Peter Zijlstra , Vincent Guittot , Valentin Schneider , Aubrey Li , Mel Gorman Subject: [PATCH 6/9] sched/fair: Make select_idle_cpu() proportional to cores Date: Mon, 26 Jul 2021 11:22:44 +0100 Message-Id: <20210726102247.21437-7-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210726102247.21437-1-mgorman@techsingularity.net> References: <20210726102247.21437-1-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra (Intel) Instead of calculating how many (logical) CPUs to scan, compute how many cores to scan. This changes behaviour for anything !SMT2. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Mel Gorman --- kernel/sched/core.c | 17 ++++++++++++----- kernel/sched/fair.c | 11 +++++++++-- kernel/sched/sched.h | 2 ++ 3 files changed, 23 insertions(+), 7 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2d9ff40f4661..7c073b67f1ea 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8647,11 +8647,18 @@ int sched_cpu_activate(unsigned int cpu) balance_push_set(cpu, false); #ifdef CONFIG_SCHED_SMT - /* - * When going up, increment the number of cores with SMT present. - */ - if (cpumask_weight(cpu_smt_mask(cpu)) == 2) - static_branch_inc_cpuslocked(&sched_smt_present); + do { + int weight = cpumask_weight(cpu_smt_mask(cpu)); + + if (weight > sched_smt_weight) + sched_smt_weight = weight; + + /* + * When going up, increment the number of cores with SMT present. + */ + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_inc_cpuslocked(&sched_smt_present); + } while (0); #endif set_cpu_active(cpu, true); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 125c020746b8..20b9255ebf97 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6076,6 +6076,8 @@ static inline int __select_idle_cpu(int cpu, struct task_struct *p) DEFINE_STATIC_KEY_FALSE(sched_smt_present); EXPORT_SYMBOL_GPL(sched_smt_present); +int __read_mostly sched_smt_weight = 1; + static inline void set_idle_cores(int cpu, int val) { struct sched_domain_shared *sds; @@ -6194,6 +6196,8 @@ static inline bool test_idle_cores(int cpu, bool def) return def; } +#define sched_smt_weight 1 + static inline int select_idle_core(struct task_struct *p, int core, struct cpumask *cpus, int *idle_cpu) { return __select_idle_cpu(core, p); @@ -6206,6 +6210,8 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd #endif /* CONFIG_SCHED_SMT */ +#define sis_min_cores 2 + /* * Scan the LLC domain for idle CPUs; this is dynamically regulated by * comparing the average scan cost (tracked in sd->avg_scan_cost) against the @@ -6246,11 +6252,12 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool avg_cost = this_sd->avg_scan_cost + 1; span_avg = sd->span_weight * avg_idle; - if (span_avg > 4*avg_cost) + if (span_avg > sis_min_cores * avg_cost) nr = div_u64(span_avg, avg_cost); else - nr = 4; + nr = sis_min_cores; + nr *= sched_smt_weight; time = cpu_clock(this); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e31179e6c6ff..4d47a0969710 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1351,6 +1351,8 @@ do { \ #ifdef CONFIG_SCHED_SMT extern void __update_idle_core(struct rq *rq); +extern int sched_smt_weight; + static inline void update_idle_core(struct rq *rq) { if (static_branch_unlikely(&sched_smt_present)) -- 2.26.2