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=-9.9 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 B5EB0C3A59B for ; Fri, 30 Aug 2019 17:56:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DA9420659 for ; Fri, 30 Aug 2019 17:56:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="oK9bcoDr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728202AbfH3Rz4 (ORCPT ); Fri, 30 Aug 2019 13:55:56 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:34218 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728155AbfH3Rzx (ORCPT ); Fri, 30 Aug 2019 13:55:53 -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 x7UHt6HJ088795; Fri, 30 Aug 2019 17:55:11 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-2019-08-05; bh=sBOrdZqaF621yiyYw5GaDxzIsvuxTOLO9r6UrcGwGRY=; b=oK9bcoDrQGrJVVAkJoZpQeir2W+YYvxF22Ba9P9sDa5Q65KshJsVcgX0mErt0jw0jBYF he+tAjjDi05jgpysBh8LDMyW2m0m4w99/5nhXS2A6DQ3kbKe7SIjT2F2J/zs9cego1mw MOlqvliB9sYrZtjWivmU5sCo8Jm1+OmGp4QqcyB4cUI0sjTDEcxSb+S9a/Mfv3kL/9C4 0EPebkCofoiShKYPoDyEALVSmawvXgUtUbrPCxMdBOavCpIX9IZ4k8nz1WTjHODfbb/5 Lv4Or6J6KbzhIQU16Zm4HG8A3WAGQmuW8Qnoja/BGKsOR+fM7+GazmGAFWpqKicrb+I9 Pg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 2uq8fsg214-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Aug 2019 17:55:11 +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 x7UHrA86047245; Fri, 30 Aug 2019 17:54:36 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 2upkrgnseb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Aug 2019 17:54:36 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x7UHsYMs002056; Fri, 30 Aug 2019 17:54:35 GMT Received: from smazumda-Precision-T1600.us.oracle.com (/10.132.91.113) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 30 Aug 2019 10:54:34 -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, parth@linux.ibm.com, patrick.bellasi@arm.com Subject: [RFC PATCH 4/9] sched: SIS_CORE to disable idle core search Date: Fri, 30 Aug 2019 10:49:39 -0700 Message-Id: <20190830174944.21741-5-subhra.mazumdar@oracle.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20190830174944.21741-1-subhra.mazumdar@oracle.com> References: <20190830174944.21741-1-subhra.mazumdar@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9365 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=757 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908300174 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9365 signatures=668685 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=819 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908300174 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use SIS_CORE to disable idle core search. For some workloads select_idle_core becomes a scalability bottleneck, removing it improves throughput. Also there are workloads where disabling it can hurt latency, so need to have an option. Signed-off-by: subhra mazumdar --- kernel/sched/fair.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c31082d..23ec9c6 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6268,9 +6268,11 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) if (!sd) return target; - i = select_idle_core(p, sd, target); - if ((unsigned)i < nr_cpumask_bits) - return i; + if (sched_feat(SIS_CORE)) { + i = select_idle_core(p, sd, target); + if ((unsigned)i < nr_cpumask_bits) + return i; + } i = select_idle_cpu(p, sd, target); if ((unsigned)i < nr_cpumask_bits) -- 2.9.3