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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 615E6C433FE for ; Fri, 21 Oct 2022 06:16:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230137AbiJUGQb (ORCPT ); Fri, 21 Oct 2022 02:16:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230126AbiJUGQ1 (ORCPT ); Fri, 21 Oct 2022 02:16:27 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 802F4102DF6 for ; Thu, 20 Oct 2022 23:16:26 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id f8-20020a17090a664800b00212464cd49fso1883435pjm.4 for ; Thu, 20 Oct 2022 23:16:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=hVI308eXyS8Lbu1XFDgJY09yiy/y64U8mWrCVAZtfNM=; b=ApOsebNMMrUy1nIx9uaw7MCe9ozsGFebYEhBLz0bsBGKXFN129y/H60GbCNJZsA9iX hwsUE9Z2hqIjcaf8wEsh4qz6GtRIbp6UK2WD0PeZ0gnEFZojbgAsAjRGBYeBsZzQY/rk mdA+TPES9mVRCvQ3uBb77fJAq7rfD5iqvrmB9GZUcsTkC2nlJcJ6NWenQDAvFktb/zA9 4iS7qgImoGOZcEdP5Q/t0LgUISEoSSXgvwjpuch/meb4HXpzSM8/75GBDzTBZQrl9DLu gecBtwLI7dxO/7Wzp7s43WQYUw17KPE68jK2Fd/D+9UR7Adf5blpFf/TixbL/cY1yPPl enWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=hVI308eXyS8Lbu1XFDgJY09yiy/y64U8mWrCVAZtfNM=; b=jyZRBLjOEW9oeQPIgm41VZUxlY3Jsobhetfp8SnQZbiL6Y9Ij8IOWE2iY5NrEUaHPa JZyECnKB6jFODJJsCTqAFLTUg738jTIilxhf+3rqeYpZN3hYasNvLg0SjH3H5HKBYhYx MGDd14zXLF7U2qRvbJvShJ/vua9711sLpO8T95qVqj8PvFd4ZhSBx94njU/G2v1RssMu 5QtAJcr1VxMaXoViI4rSd1hSimvOumDtZrQ6z4FrH58tsjSPDw0+8k0AXqYPaZSQHlFg UA8FsWUrJKmsb7m4cRJf/BjktFTRlHqE9lw7TQTltDn8n9u6gZ3G+R9nssF05BAF6YfT flZw== X-Gm-Message-State: ACrzQf0eBY91qTJmm/YCUUrVWhdHj+bL6k1HoQIPViC7ic5MIorwsmwR 82qlA2gg1+KrL5iebALnLvlp+Q== X-Google-Smtp-Source: AMsMyM6DxwLTzE9ETzTH1ou+CRSd18+kc0m8Tvrp6rLi1Ure9JvkMSuTkm9C9fMGW45Hswz0GBWmwQ== X-Received: by 2002:a17:90b:1b0b:b0:20d:7c31:e75d with SMTP id nu11-20020a17090b1b0b00b0020d7c31e75dmr19924620pjb.101.1666332985621; Thu, 20 Oct 2022 23:16:25 -0700 (PDT) Received: from C02G87K0MD6R.bytedance.net ([139.177.225.244]) by smtp.gmail.com with ESMTPSA id o11-20020a17090a4b4b00b0020d45a155d9sm327532pjl.35.2022.10.20.23.16.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Oct 2022 23:16:24 -0700 (PDT) From: Hao Jia To: mingo@redhat.com, peterz@infradead.org, mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mgorman@techsingularity.net Cc: linux-kernel@vger.kernel.org, Hao Jia Subject: [PATCH 2/2] sched/core: Optimize the order of scanning CPU Date: Fri, 21 Oct 2022 14:15:58 +0800 Message-Id: <20221021061558.34767-3-jiahao.os@bytedance.com> X-Mailer: git-send-email 2.37.0 (Apple Git-136) In-Reply-To: <20221021061558.34767-1-jiahao.os@bytedance.com> References: <20221021061558.34767-1-jiahao.os@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When select_idle_capacity() starts scanning for an idle CPU, it starts with target CPU that has already been checked in select_idle_sibling(). So, we finally try the target CPU. Similarly for task_numa_assign(), we have just checked numa_migrate_on of dst_cpu, so start from the next CPU. This also works for steal_cookie_task(), the first scan must fail and start directly from the next one. Signed-off-by: Hao Jia --- kernel/sched/core.c | 2 +- kernel/sched/fair.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5800b0623ff3..f6ad68714546 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6154,7 +6154,7 @@ static bool steal_cookie_task(int cpu, struct sched_domain *sd) { int i; - for_each_cpu_wrap(i, sched_domain_span(sd), cpu) { + for_each_cpu_wrap(i, sched_domain_span(sd), cpu + 1) { if (i == cpu) continue; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b7cbec539c77..d95ee285734e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1824,7 +1824,7 @@ static void task_numa_assign(struct task_numa_env *env, int start = env->dst_cpu; /* Find alternative idle CPU. */ - for_each_cpu_wrap(cpu, cpumask_of_node(env->dst_nid), start) { + for_each_cpu_wrap(cpu, cpumask_of_node(env->dst_nid), start + 1) { if (cpu == env->best_cpu || !idle_cpu(cpu) || !cpumask_test_cpu(cpu, env->p->cpus_ptr)) { continue; @@ -6663,7 +6663,7 @@ select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target) task_util = uclamp_task_util(p); - for_each_cpu_wrap(cpu, cpus, target) { + for_each_cpu_wrap(cpu, cpus, target + 1) { unsigned long cpu_cap = capacity_of(cpu); if (!available_idle_cpu(cpu) && !sched_idle_cpu(cpu)) -- 2.37.0