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=-8.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, 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 E7E4EC48BD3 for ; Thu, 27 Jun 2019 01:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8E6221882 for ; Thu, 27 Jun 2019 01:35:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="cMK89/vD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726967AbfF0BfW (ORCPT ); Wed, 26 Jun 2019 21:35:22 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:56496 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbfF0BfV (ORCPT ); Wed, 26 Jun 2019 21:35:21 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5R1YVOj126968; Thu, 27 Jun 2019 01:34:31 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=x+M0Mv5Zb9UXiRYfxKM6z9oZmTfxBCdsXIjXQ8gVKSc=; b=cMK89/vDK+iJSBobMebhV6kATak9oM4LlA4o2JRVhOrKeSJ8vnsyEYYdsnodlPvH9G4E nE9HUXfTMD84Hdja9SA6U8JPvs7Z9+WlQgen8A0l5fO223qhJji0WwFWWoZsOQxY4SQ9 xgeiUGYhGIWwSoUOg6zhlubTRpmsP3RrrqqUex56qCh8FRXTkEcylUClrvuyrSo2yq2P 5kxJfUphdi7rJLw8P5WudZnQq/SbLiFie4SDuU3hCKM1ffml9zUvxe7SAt/taIcbaZ/h r6qUHZgBjOB1aRScyKHPB49+Ap0rzpZlkFq4x2bnnrVOQOI2gHe2MzR16ZUJ8lwp7poa dA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2t9c9pwdm1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 27 Jun 2019 01:34:31 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5R1Y9XO018162; Thu, 27 Jun 2019 01:34:30 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 2tat7d4a3y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 27 Jun 2019 01:34:30 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x5R1YR8N007567; Thu, 27 Jun 2019 01:34:27 GMT Received: from smazumda-Precision-T1600.us.oracle.com (/10.132.91.175) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 26 Jun 2019 18:34:27 -0700 From: subhra mazumdar To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mingo@redhat.com, tglx@linutronix.de, steven.sistare@oracle.com, dhaval.giani@oracle.com, daniel.lezcano@linaro.org, vincent.guittot@linaro.org, viresh.kumar@linaro.org, tim.c.chen@linux.intel.com, mgorman@techsingularity.net Subject: [PATCH v3 3/7] sched: rotate the cpu search window for better spread Date: Wed, 26 Jun 2019 18:29:15 -0700 Message-Id: <20190627012919.4341-4-subhra.mazumdar@oracle.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20190627012919.4341-1-subhra.mazumdar@oracle.com> References: <20190627012919.4341-1-subhra.mazumdar@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9300 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=862 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906270016 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9300 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=905 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906270017 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rotate the cpu search window for better spread of threads. This will ensure an idle cpu will quickly be found if one exists. Signed-off-by: subhra mazumdar --- kernel/sched/fair.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b58f08f..c1ca88e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6188,7 +6188,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t u64 avg_cost, avg_idle; u64 time, cost; s64 delta; - int cpu, limit, floor, nr = INT_MAX; + int cpu, limit, floor, target_tmp, nr = INT_MAX; this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); if (!this_sd) @@ -6219,9 +6219,15 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t } } + if (per_cpu(next_cpu, target) != -1) + target_tmp = per_cpu(next_cpu, target); + else + target_tmp = target; + time = local_clock(); - for_each_cpu_wrap(cpu, sched_domain_span(sd), target) { + for_each_cpu_wrap(cpu, sched_domain_span(sd), target_tmp) { + per_cpu(next_cpu, target) = cpu; if (!--nr) return -1; if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) -- 2.9.3