From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757286AbZKWLxT (ORCPT ); Mon, 23 Nov 2009 06:53:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757273AbZKWLxR (ORCPT ); Mon, 23 Nov 2009 06:53:17 -0500 Received: from hera.kernel.org ([140.211.167.34]:56016 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757278AbZKWLxO (ORCPT ); Mon, 23 Nov 2009 06:53:14 -0500 Date: Mon, 23 Nov 2009 11:52:43 GMT From: tip-bot for Yinghai Lu Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, yinghai@kernel.org, rusty@rustcorp.com.au, torvalds@linux-foundation.org, akpm@linux-foundation.org, tj@kernel.org, tglx@linutronix.de, rientjes@google.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, yinghai@kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, rusty@rustcorp.com.au, tj@kernel.org, tglx@linutronix.de, rientjes@google.com, mingo@elte.hu In-Reply-To: <4B07A739.3030104@kernel.org> References: <4B07A739.3030104@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86, numa: Use near(er) online node instead of roundrobin for NUMA Message-ID: Git-Commit-ID: d9c2d5ac6af87b4491bff107113aaf16f6c2b2d9 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 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 Commit-ID: d9c2d5ac6af87b4491bff107113aaf16f6c2b2d9 Gitweb: http://git.kernel.org/tip/d9c2d5ac6af87b4491bff107113aaf16f6c2b2d9 Author: Yinghai Lu AuthorDate: Sat, 21 Nov 2009 00:23:37 -0800 Committer: Ingo Molnar CommitDate: Mon, 23 Nov 2009 10:06:24 +0100 x86, numa: Use near(er) online node instead of roundrobin for NUMA CPU to node mapping is set via the following sequence: 1. numa_init_array(): Set up roundrobin from cpu to online node 2. init_cpu_to_node(): Set that according to apicid_to_node[] according to srat only handle the node that is online, and leave other cpu on node without ram (aka not online) to still roundrobin. 3. later call srat_detect_node for Intel/AMD, will use first_online node or nearby node. Problem is that setup_per_cpu_areas() is not called between 2 and 3, the per_cpu for cpu on node with ram is on different node, and could put that on node with two hops away. So try to optimize this and add find_near_online_node() and call init_cpu_to_node(). Signed-off-by: Yinghai Lu Cc: Tejun Heo Cc: Linus Torvalds Cc: Thomas Gleixner Cc: H. Peter Anvin Cc: Rusty Russell Cc: David Rientjes Cc: Andrew Morton LKML-Reference: <4B07A739.3030104@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel.c | 6 +++++- arch/x86/mm/numa_64.c | 21 ++++++++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 40e1835..c900b73 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -263,8 +263,12 @@ static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c) /* Don't do the funky fallback heuristics the AMD version employs for now. */ node = apicid_to_node[apicid]; - if (node == NUMA_NO_NODE || !node_online(node)) + if (node == NUMA_NO_NODE) node = first_node(node_online_map); + else if (!node_online(node)) { + /* reuse the value from init_cpu_to_node() */ + node = cpu_to_node(cpu); + } numa_set_node(cpu, node); printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node); diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c index 3acd870..83bbc70 100644 --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -764,6 +764,25 @@ static __init int numa_setup(char *opt) early_param("numa", numa_setup); #ifdef CONFIG_NUMA + +static __init int find_near_online_node(int node) +{ + int n, val; + int min_val = INT_MAX; + int best_node = -1; + + for_each_online_node(n) { + val = node_distance(node, n); + + if (val < min_val) { + min_val = val; + best_node = n; + } + } + + return best_node; +} + /* * Setup early cpu_to_node. * @@ -795,7 +814,7 @@ void __init init_cpu_to_node(void) if (node == NUMA_NO_NODE) continue; if (!node_online(node)) - continue; + node = find_near_online_node(node); numa_set_node(cpu, node); } }