From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59974 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753992AbdGJPZJ (ORCPT ); Mon, 10 Jul 2017 11:25:09 -0400 Subject: Patch "sched/numa: Override part of migrate_degrades_locality() when idle balancing" has been added to the 4.12-stable tree To: riel@redhat.com, efault@gmx.de, gregkh@linuxfoundation.org, jhladky@redhat.com, mgorman@suse.de, mgorman@techsingularity.net, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Mon, 10 Jul 2017 17:24:54 +0200 Message-ID: <149970029411191@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled sched/numa: Override part of migrate_degrades_locality() when idle balancing to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sched-numa-override-part-of-migrate_degrades_locality-when-idle-balancing.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 739294fb03f590401bbd7faa6d31a507e3ffada5 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Fri, 23 Jun 2017 12:55:27 -0400 Subject: sched/numa: Override part of migrate_degrades_locality() when idle balancing From: Rik van Riel commit 739294fb03f590401bbd7faa6d31a507e3ffada5 upstream. 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 Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman --- kernel/sched/fair.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6661,6 +6661,10 @@ static int migrate_degrades_locality(str 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); Patches currently in stable-queue which might be from riel@redhat.com are queue-4.12/sched-numa-hide-numa_wake_affine-from-up-build.patch queue-4.12/sched-numa-use-down_read_trylock-for-the-mmap_sem.patch queue-4.12/sched-core-implement-new-approach-to-scale-select_idle_cpu.patch queue-4.12/sched-fair-remove-effective_load.patch queue-4.12/sched-numa-implement-numa-node-level-wake_affine.patch queue-4.12/sched-fair-simplify-wake_affine-for-the-single-socket-case.patch queue-4.12/sched-fair-cpumask-export-for_each_cpu_wrap.patch queue-4.12/sched-numa-override-part-of-migrate_degrades_locality-when-idle-balancing.patch