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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 1321BC2B9F7 for ; Wed, 26 May 2021 09:18:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5FB961248 for ; Wed, 26 May 2021 09:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233157AbhEZJUG (ORCPT ); Wed, 26 May 2021 05:20:06 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:3948 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232412AbhEZJUF (ORCPT ); Wed, 26 May 2021 05:20:05 -0400 Received: from dggems702-chm.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4Fqlfh0xv7zCxB2; Wed, 26 May 2021 17:15:40 +0800 (CST) Received: from dggemi761-chm.china.huawei.com (10.1.198.147) by dggems702-chm.china.huawei.com (10.3.19.179) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Wed, 26 May 2021 17:18:30 +0800 Received: from SWX921481.china.huawei.com (10.126.203.64) by dggemi761-chm.china.huawei.com (10.1.198.147) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 26 May 2021 17:18:27 +0800 From: Barry Song To: , , , , , , CC: , , , , , , , , Barry Song Subject: [PATCH] sched: fair: don't depend on wake_wide if waker and wakee are already in same LLC Date: Wed, 26 May 2021 21:10:57 +1200 Message-ID: <20210526091057.1800-1-song.bao.hua@hisilicon.com> X-Mailer: git-send-email 2.21.0.windows.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.126.203.64] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggemi761-chm.china.huawei.com (10.1.198.147) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org when waker and wakee are already in the same LLC, it is pointless to worry about the competition caused by pulling wakee to waker's LLC domain. Signed-off-by: Barry Song --- kernel/sched/fair.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3248e24a90b0..cfb1bd47acc3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6795,7 +6795,15 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags) new_cpu = prev_cpu; } - want_affine = !wake_wide(p) && cpumask_test_cpu(cpu, p->cpus_ptr); + /* + * we use wake_wide to make smarter pull and avoid cruel + * competition because of jam-packed tasks in waker's LLC + * domain. But if waker and wakee have been already in + * same LLC domain, it seems it is pointless to depend + * on wake_wide + */ + want_affine = (cpus_share_cache(cpu, prev_cpu) || !wake_wide(p)) && + cpumask_test_cpu(cpu, p->cpus_ptr); } rcu_read_lock(); -- 2.25.1