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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id A39DFC5CFF1 for ; Tue, 12 Jun 2018 17:48:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 583E32086D for ; Tue, 12 Jun 2018 17:48:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="O5BjAmkU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 583E32086D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934369AbeFLRsq (ORCPT ); Tue, 12 Jun 2018 13:48:46 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:59894 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933076AbeFLRsj (ORCPT ); Tue, 12 Jun 2018 13:48:39 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w5CHjvBR072148; Tue, 12 Jun 2018 17:48:08 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-2017-10-26; bh=RkeuoDl92iFD1adBalzfY5dXtOqBi+bylp8KtP2Cg7s=; b=O5BjAmkUaUMIc+GNFfyz/08Y/wL0QexE16iNKGYcDGD5VhobH9CUWTkbIyVZ4r+miHmT kuaJLsz8N9TPnS2IjeLFdmsCjMsbk9E8Sth4K0xi9Aam5sgl81gK0yMeC6hTcF+Ino32 lPUY0wjWKy/56rMMB6ASjkbqTNt6S1nWF+ZdE+qLPC6iwtJ6M5iPIEDNP5eIlLcSs/8P s8RTJIJJKnXzS4s67BH1XRlO2FltX6MxLzVZW20zzTF77mYRvIXYckTdPaeOywlscD7Z iNk6FVeuH1gQ8WubycmjlCxG/1x8aej8Vd8kqc0wwX6rJ5uciMwL1ykMrhSb+DZUKMEF 0A== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2130.oracle.com with ESMTP id 2jg6b1k4qt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Jun 2018 17:48:08 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w5CHm8B5007518 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Jun 2018 17:48:08 GMT Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w5CHm8GY021157; Tue, 12 Jun 2018 17:48:08 GMT Received: from smazumda-Precision-T1600.us.oracle.com (/10.132.91.87) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 12 Jun 2018 10:48:07 -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, rohit.k.jain@oracle.com, daniel.lezcano@linaro.org Subject: [PATCH 5/5] sched: SIS_CORE to disable idle core search Date: Tue, 12 Jun 2018 10:50:02 -0700 Message-Id: <20180612175002.31453-6-subhra.mazumdar@oracle.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20180612175002.31453-1-subhra.mazumdar@oracle.com> References: <20180612175002.31453-1-subhra.mazumdar@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8922 signatures=668702 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=396 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806120198 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 849c7c8..35a076e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6464,9 +6464,11 @@ 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