From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out5-smtp.messagingengine.com ([66.111.4.29]:41054 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751469AbbFCDWj (ORCPT ); Tue, 2 Jun 2015 23:22:39 -0400 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id C79C9203F3 for ; Tue, 2 Jun 2015 23:22:38 -0400 (EDT) Subject: FAILED: patch "[PATCH] mm, numa: really disable NUMA balancing by default on single" failed to apply to 3.10-stable tree To: mgorman@suse.de, akpm@linux-foundation.org, riel@redhat.com, stable@vger.kernel.org, torvalds@linux-foundation.org Cc: From: Date: Wed, 03 Jun 2015 12:22:36 +0900 Message-ID: <143330175664@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: The patch below does not apply to the 3.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From b0dc2b9bb4ab782115b964310518ee0b17784277 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 14 May 2015 15:17:09 -0700 Subject: [PATCH] mm, numa: really disable NUMA balancing by default on single node machines NUMA balancing is meant to be disabled by default on UMA machines but the check is using nr_node_ids (highest node) instead of num_online_nodes (online nodes). The consequences are that a UMA machine with a node ID of 1 or higher will enable NUMA balancing. This will incur useless overhead due to minor faults with the impact depending on the workload. These are the impact on the stats when running a kernel build on a single node machine whose node ID happened to be 1: vanilla patched NUMA base PTE updates 5113158 0 NUMA huge PMD updates 643 0 NUMA page range updates 5442374 0 NUMA hint faults 2109622 0 NUMA hint local faults 2109622 0 NUMA hint local percent 100 100 NUMA pages migrated 0 0 Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: [3.8+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ede26291d4aa..747743237d9f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2518,7 +2518,7 @@ static void __init check_numabalancing_enable(void) if (numabalancing_override) set_numabalancing_state(numabalancing_override == 1); - if (nr_node_ids > 1 && !numabalancing_override) { + if (num_online_nodes() > 1 && !numabalancing_override) { pr_info("%s automatic NUMA balancing. " "Configure with numa_balancing= or the " "kernel.numa_balancing sysctl",