Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751342AbdFXH0B (ORCPT ); Sat, 24 Jun 2017 03:26:01 -0400 Received: from terminus.zytor.com ([65.50.211.136]:43501 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751247AbdFXHZ7 (ORCPT ); Sat, 24 Jun 2017 03:25:59 -0400 Date: Sat, 24 Jun 2017 00:22:16 -0700 From: tip-bot for Rik van Riel Message-ID: Cc: jhladky@redhat.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de, efault@gmx.de, riel@redhat.com, hpa@zytor.com, mgorman@suse.de Reply-To: mgorman@suse.de, hpa@zytor.com, efault@gmx.de, riel@redhat.com, peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org, jhladky@redhat.com, linux-kernel@vger.kernel.org In-Reply-To: <20170623165530.22514-2-riel@redhat.com> References: <20170623165530.22514-2-riel@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/numa: Override part of migrate_degrades_locality() when idle balancing Git-Commit-ID: 739294fb03f590401bbd7faa6d31a507e3ffada5 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1747 Lines: 46 Commit-ID: 739294fb03f590401bbd7faa6d31a507e3ffada5 Gitweb: http://git.kernel.org/tip/739294fb03f590401bbd7faa6d31a507e3ffada5 Author: Rik van Riel AuthorDate: Fri, 23 Jun 2017 12:55:27 -0400 Committer: Ingo Molnar CommitDate: Sat, 24 Jun 2017 08:57:46 +0200 sched/numa: Override part of migrate_degrades_locality() when idle balancing Several tests in the NAS benchmark seem to run a lot slower with NUMA balancing enabled, than with NUMA balancing disabled. The slower run time corresponds with increased idle time. Overriding the final test of migrate_degrades_locality (but still doing the other NUMA tests first) seems to improve performance of those benchmarks. Reported-by: Jirka Hladky Signed-off-by: Rik van Riel Cc: Linus Torvalds Cc: Mel Gorman Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20170623165530.22514-2-riel@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 694c258..6e0c052 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6688,6 +6688,10 @@ static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env) if (dst_nid == p->numa_preferred_nid) return 0; + /* Leaving a core idle is often worse than degrading locality. */ + if (env->idle != CPU_NOT_IDLE) + return -1; + if (numa_group) { src_faults = group_faults(p, src_nid); dst_faults = group_faults(p, dst_nid);