Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761337AbZCSUr0 (ORCPT ); Thu, 19 Mar 2009 16:47:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759466AbZCSUrO (ORCPT ); Thu, 19 Mar 2009 16:47:14 -0400 Received: from smtp.ultrahosting.com ([74.213.174.254]:55375 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756391AbZCSUrN (ORCPT ); Thu, 19 Mar 2009 16:47:13 -0400 Date: Thu, 19 Mar 2009 16:43:55 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@qirst.com To: Mel Gorman cc: Linux Memory Management List , Pekka Enberg , Rik van Riel , KOSAKI Motohiro , Johannes Weiner , Nick Piggin , Linux Kernel Mailing List , Lin Ming , Zhang Yanmin , Peter Zijlstra Subject: Re: [PATCH 20/35] Use a pre-calculated value for num_online_nodes() In-Reply-To: Message-ID: References: <1237196790-7268-1-git-send-email-mel@csn.ul.ie> <1237196790-7268-21-git-send-email-mel@csn.ul.ie> <20090316163626.GJ24293@csn.ul.ie> <20090318150833.GC4629@csn.ul.ie> <20090318180152.GB24462@csn.ul.ie> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5484 Lines: 166 Trying to the same in the style of nr_node_ids etc. Subject: Provide nr_online_nodes and nr_possible_nodes It seems that its beneficial to have a less expensive way to check for the number of currently active and possible nodes in a NUMA system. This will simplify further kernel optimizations for the cases in which only a single node is online or possible. Signed-off-by: Christoph Lameter Index: linux-2.6/include/linux/nodemask.h =================================================================== --- linux-2.6.orig/include/linux/nodemask.h 2009-03-19 15:04:28.000000000 -0500 +++ linux-2.6/include/linux/nodemask.h 2009-03-19 15:33:18.000000000 -0500 @@ -408,6 +408,20 @@ #define next_online_node(nid) next_node((nid), node_states[N_ONLINE]) extern int nr_node_ids; +extern int nr_online_nodes; +extern int nr_possible_nodes; + +static inline void node_set_online(int nid) +{ + node_set_state(nid, N_ONLINE); + nr_online_nodes = num_node_state(N_ONLINE); +} + +static inline void node_set_offline(int nid) +{ + node_clear_state(nid, N_ONLINE); + nr_online_nodes = num_node_state(N_ONLINE); +} #else static inline int node_state(int node, enum node_states state) @@ -434,7 +448,8 @@ #define first_online_node 0 #define next_online_node(nid) (MAX_NUMNODES) #define nr_node_ids 1 - +#define nr_online_nodes 1 +#define nr_possible_nodes 1 #endif #define node_online_map node_states[N_ONLINE] @@ -454,8 +469,7 @@ #define node_online(node) node_state((node), N_ONLINE) #define node_possible(node) node_state((node), N_POSSIBLE) -#define node_set_online(node) node_set_state((node), N_ONLINE) -#define node_set_offline(node) node_clear_state((node), N_ONLINE) + #define for_each_node(node) for_each_node_state(node, N_POSSIBLE) #define for_each_online_node(node) for_each_node_state(node, N_ONLINE) Index: linux-2.6/mm/hugetlb.c =================================================================== --- linux-2.6.orig/mm/hugetlb.c 2009-03-19 15:11:49.000000000 -0500 +++ linux-2.6/mm/hugetlb.c 2009-03-19 15:12:13.000000000 -0500 @@ -875,7 +875,7 @@ * can no longer free unreserved surplus pages. This occurs when * the nodes with surplus pages have no free pages. */ - unsigned long remaining_iterations = num_online_nodes(); + unsigned long remaining_iterations = nr_online_nodes; /* Uncommit the reservation */ h->resv_huge_pages -= unused_resv_pages; @@ -904,7 +904,7 @@ h->surplus_huge_pages--; h->surplus_huge_pages_node[nid]--; nr_pages--; - remaining_iterations = num_online_nodes(); + remaining_iterations = nr_online_nodes; } } } Index: linux-2.6/mm/page_alloc.c =================================================================== --- linux-2.6.orig/mm/page_alloc.c 2009-03-19 15:12:19.000000000 -0500 +++ linux-2.6/mm/page_alloc.c 2009-03-19 15:30:21.000000000 -0500 @@ -168,6 +168,10 @@ #if MAX_NUMNODES > 1 int nr_node_ids __read_mostly = MAX_NUMNODES; EXPORT_SYMBOL(nr_node_ids); +int nr_online_nodes __read_mostly = 1; +EXPORT_SYMBOL(nr_online_nodes); +int nr_possible_nodes __read_mostly = MAX_NUMNODES; +EXPORT_SYMBOL(nr_possible_nodes); #endif int page_group_by_mobility_disabled __read_mostly; @@ -2115,7 +2119,7 @@ } -#define MAX_NODE_LOAD (num_online_nodes()) +#define MAX_NODE_LOAD nr_online_nodes static int node_load[MAX_NUMNODES]; /** Index: linux-2.6/mm/slab.c =================================================================== --- linux-2.6.orig/mm/slab.c 2009-03-19 15:13:45.000000000 -0500 +++ linux-2.6/mm/slab.c 2009-03-19 15:15:28.000000000 -0500 @@ -881,7 +881,6 @@ */ static int use_alien_caches __read_mostly = 1; -static int numa_platform __read_mostly = 1; static int __init noaliencache_setup(char *s) { use_alien_caches = 0; @@ -1434,9 +1433,8 @@ int order; int node; - if (num_possible_nodes() == 1) { + if (nr_possible_nodes == 1) { use_alien_caches = 0; - numa_platform = 0; } for (i = 0; i < NUM_INIT_LISTS; i++) { @@ -3526,7 +3524,7 @@ * variable to skip the call, which is mostly likely to be present in * the cache. */ - if (numa_platform && cache_free_alien(cachep, objp)) + if (nr_possible_nodes > 1 && cache_free_alien(cachep, objp)) return; if (likely(ac->avail < ac->limit)) { Index: linux-2.6/mm/slub.c =================================================================== --- linux-2.6.orig/mm/slub.c 2009-03-19 15:13:15.000000000 -0500 +++ linux-2.6/mm/slub.c 2009-03-19 15:13:38.000000000 -0500 @@ -3648,7 +3648,7 @@ to_cpumask(l->cpus)); } - if (num_online_nodes() > 1 && !nodes_empty(l->nodes) && + if (nr_online_nodes > 1 && !nodes_empty(l->nodes) && len < PAGE_SIZE - 60) { len += sprintf(buf + len, " nodes="); len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50, Index: linux-2.6/net/sunrpc/svc.c =================================================================== --- linux-2.6.orig/net/sunrpc/svc.c 2009-03-19 15:16:21.000000000 -0500 +++ linux-2.6/net/sunrpc/svc.c 2009-03-19 15:16:51.000000000 -0500 @@ -124,7 +124,7 @@ { unsigned int node; - if (num_online_nodes() > 1) { + if (nr_online_nodes > 1) { /* * Actually have multiple NUMA nodes, * so split pools on NUMA node boundaries -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/