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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 0A051C67790 for ; Wed, 25 Jul 2018 14:29:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAC6B20852 for ; Wed, 25 Jul 2018 14:29:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAC6B20852 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.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 S1729495AbeGYPlA (ORCPT ); Wed, 25 Jul 2018 11:41:00 -0400 Received: from terminus.zytor.com ([198.137.202.136]:49201 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728051AbeGYPlA (ORCPT ); Wed, 25 Jul 2018 11:41:00 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w6PESeog402501 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 25 Jul 2018 07:28:40 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w6PESefV402497; Wed, 25 Jul 2018 07:28:40 -0700 Date: Wed, 25 Jul 2018 07:28:40 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Srikar Dronamraju Message-ID: Cc: torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com, mingo@kernel.org, srikar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, mgorman@techsingularity.net, peterz@infradead.org, riel@surriel.com Reply-To: mingo@kernel.org, srikar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, mgorman@techsingularity.net, peterz@infradead.org, riel@surriel.com, torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com In-Reply-To: <1529514181-9842-13-git-send-email-srikar@linux.vnet.ibm.com> References: <1529514181-9842-13-git-send-email-srikar@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/numa: Remove numa_has_capacity() Git-Commit-ID: 2d4056fafa196e1ab4e7161bae4df76f9602d56d X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 2d4056fafa196e1ab4e7161bae4df76f9602d56d Gitweb: https://git.kernel.org/tip/2d4056fafa196e1ab4e7161bae4df76f9602d56d Author: Srikar Dronamraju AuthorDate: Wed, 20 Jun 2018 22:32:53 +0530 Committer: Ingo Molnar CommitDate: Wed, 25 Jul 2018 11:41:08 +0200 sched/numa: Remove numa_has_capacity() task_numa_find_cpu() helps to find the CPU to swap/move the task to. It's guarded by numa_has_capacity(). However node not having capacity shouldn't deter a task swapping if it helps NUMA placement. Further load_too_imbalanced(), which evaluates possibilities of move/swap, provides similar checks as numa_has_capacity. Hence remove numa_has_capacity() to enhance possibilities of task swapping even if load is imbalanced. Running SPECjbb2005 on a 4 node machine and comparing bops/JVM JVMS LAST_PATCH WITH_PATCH %CHANGE 16 25657.9 25804.1 0.569 1 74435 73413 -1.37 Signed-off-by: Srikar Dronamraju Signed-off-by: Peter Zijlstra (Intel) Acked-by: Rik van Riel Cc: Linus Torvalds Cc: Mel Gorman Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1529514181-9842-13-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 36 +++--------------------------------- 1 file changed, 3 insertions(+), 33 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7b4eddec3ccc..3bcf0e864613 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1456,7 +1456,6 @@ struct numa_stats { unsigned long compute_capacity; unsigned int nr_running; - int has_free_capacity; }; /* @@ -1483,8 +1482,7 @@ static void update_numa_stats(struct numa_stats *ns, int nid) * the @ns structure is NULL'ed and task_numa_compare() will * not find this node attractive. * - * We'll either bail at !has_free_capacity, or we'll detect a huge - * imbalance and bail there. + * We'll detect a huge imbalance and bail there. */ if (!cpus) return; @@ -1495,7 +1493,6 @@ static void update_numa_stats(struct numa_stats *ns, int nid) capacity = min_t(unsigned, capacity, DIV_ROUND_CLOSEST(ns->compute_capacity, SCHED_CAPACITY_SCALE)); - ns->has_free_capacity = (ns->nr_running < capacity); } struct task_numa_env { @@ -1698,31 +1695,6 @@ static void task_numa_find_cpu(struct task_numa_env *env, } } -/* Only move tasks to a NUMA node less busy than the current node. */ -static bool numa_has_capacity(struct task_numa_env *env) -{ - struct numa_stats *src = &env->src_stats; - struct numa_stats *dst = &env->dst_stats; - - if (src->has_free_capacity && !dst->has_free_capacity) - return false; - - /* - * Only consider a task move if the source has a higher load - * than the destination, corrected for CPU capacity on each node. - * - * src->load dst->load - * --------------------- vs --------------------- - * src->compute_capacity dst->compute_capacity - */ - if (src->load * dst->compute_capacity * env->imbalance_pct > - - dst->load * src->compute_capacity * 100) - return true; - - return false; -} - static int task_numa_migrate(struct task_struct *p) { struct task_numa_env env = { @@ -1777,8 +1749,7 @@ static int task_numa_migrate(struct task_struct *p) update_numa_stats(&env.dst_stats, env.dst_nid); /* Try to find a spot on the preferred nid. */ - if (numa_has_capacity(&env)) - task_numa_find_cpu(&env, taskimp, groupimp); + task_numa_find_cpu(&env, taskimp, groupimp); /* * Look at other nodes in these cases: @@ -1808,8 +1779,7 @@ static int task_numa_migrate(struct task_struct *p) env.dist = dist; env.dst_nid = nid; update_numa_stats(&env.dst_stats, env.dst_nid); - if (numa_has_capacity(&env)) - task_numa_find_cpu(&env, taskimp, groupimp); + task_numa_find_cpu(&env, taskimp, groupimp); } }