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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 31927C28CC5 for ; Sun, 9 Jun 2019 01:55:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 042F1214C6 for ; Sun, 9 Jun 2019 01:55:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="j1N+Q6/+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728081AbfFIBzU (ORCPT ); Sat, 8 Jun 2019 21:55:20 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:54442 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727444AbfFIBzU (ORCPT ); Sat, 8 Jun 2019 21:55:20 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x591rdEJ030612; Sun, 9 Jun 2019 01:54:44 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=j1N+Q6/+fFyoxnDn0l58lkMlsruewpWCLdPi1/j5S9DQN6qMkgJ/6LrrucGOe2JKyjW2 16klZr6wbzumwBJuHHtQr6VSGHWPsb5T7kImjgpDfShBAsfUtb9HmFQ4do/xTd1eMdzt ZWGg/uggEZLDGvwMMnGTePDjcjDW/dn78hfhf18tYuPLZlV893mDmTkOwNIHsnvHNwIr 89reU5EfAec+GoxYEZE8CE1Tx0hj5YoPGaIOZLJUbeQjtGFr8UclUMDHBDgP4TpBv7Er EsJCgOv3Us4Mi0dJj4h8+ne7Hg8crdX1aYK/8rg3nQMbM3QyWGwwqxelDmhF8BaoVDnC xw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2t05nqa0mf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 09 Jun 2019 01:54:44 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x591rB8Z026415; Sun, 9 Jun 2019 01:54:44 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2t024tcfmp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 09 Jun 2019 01:54:44 +0000 Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x591sd55030390; Sun, 9 Jun 2019 01:54:40 GMT Received: from smazumda-Precision-T1600.us.oracle.com (/10.132.91.175) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sat, 08 Jun 2019 18:54:39 -0700 From: subhra mazumdar To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, mingo@redhat.com, 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: Sat, 8 Jun 2019 18:49:50 -0700 Message-Id: <20190609014954.1033-4-subhra.mazumdar@oracle.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20190609014954.1033-1-subhra.mazumdar@oracle.com> References: <20190609014954.1033-1-subhra.mazumdar@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9282 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=846 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906090012 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9282 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=881 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906090013 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