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 37CE7C3A59B for ; Fri, 30 Aug 2019 17:55:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0FFF02342B for ; Fri, 30 Aug 2019 17:55:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="hRAHlA+G" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728031AbfH3Rzt (ORCPT ); Fri, 30 Aug 2019 13:55:49 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:34030 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727904AbfH3Rzs (ORCPT ); Fri, 30 Aug 2019 13:55:48 -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 x7UHt6PD088735; Fri, 30 Aug 2019 17:55:10 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=wAuaqsNTYu9PLpGsR9PztanzZXV9e3lo4XXN0aBZ7ak=; b=hRAHlA+GNBi6Flv1rXd9eR+sCusOVFNJveXPZXWPKKNjyFckv84qXx+3FXkNl7q4qrps hQWfQsP2nUte9wgn3kpfuocRoqJ+Z1NUKjeYMjhP+JPPqz+pk/PjXYaAig/028asw6VC 8R9ujkLD2dVz5zU48Av00W3BOBgvlKDNQ2WgYz+Nk0iVMYMVP1L0yJQUDmDM4pxUr7MA SAKfj10xIxmhRnEr9iBbDzoINb6VwJUGNbEb2WV4Mqsn9/zPjU6UBxCiX7cul+4CRJV8 tooWuxsWQVqP4oAn1x3aYN7YVeZOmaaqFSt8AEMr2EVx7cIrGCD74CvbXnng+PMeB+AQ IA== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 2uq8fsg20y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Aug 2019 17:55:09 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7UHrrnH072175; Fri, 30 Aug 2019 17:54:35 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3020.oracle.com with ESMTP id 2upc8xrmea-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Aug 2019 17:54:35 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x7UHsXMU014831; Fri, 30 Aug 2019 17:54:33 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 10:54:33 -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 2/9] sched: add search limit as per latency-nice Date: Fri, 30 Aug 2019 10:49:37 -0700 Message-Id: <20190830174944.21741-3-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=999 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=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 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 Put upper and lower limit on CPU search in select_idle_cpu. The lower limit is set to amount of CPUs in a core while upper limit is derived from the latency-nice of the thread. This ensures for any architecture we will usually search beyond a core. Changing the latency-nice value by user will change the search cost making it appropriate for given workload. Signed-off-by: subhra mazumdar --- kernel/sched/fair.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b08d00c..c31082d 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, nr = INT_MAX; + int cpu, floor, nr = INT_MAX; this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); if (!this_sd) @@ -6205,11 +6205,12 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t return -1; if (sched_feat(SIS_PROP)) { - u64 span_avg = sd->span_weight * avg_idle; - if (span_avg > 4*avg_cost) - nr = div_u64(span_avg, avg_cost); - else - nr = 4; + floor = cpumask_weight(topology_sibling_cpumask(target)); + if (floor < 2) + floor = 2; + nr = (p->latency_nice * sd->span_weight) / LATENCY_NICE_MAX; + if (nr < floor) + nr = floor; } time = local_clock(); -- 2.9.3