[PATCH] Replace highest_possible_node_id() with nr_node_ids

highest_possible_node_id() is currently used to calculate the last possible
node idso that the network subsystem can figure out how to size per node
arrays.

I think having the ability to determine the maximum amount of nodes in a
system at runtime is useful but then we should name this entry
correspondingly, it should return the number of node_ids, and the the value
needs to be setup only once on bootup.  The node_possible_map does not
change after bootup.

This patch introduces nr_node_ids and replaces the use of
highest_possible_node_id().  nr_node_ids is calculated on bootup when the
page allocators pagesets are initialized.

[deweerdt@free.fr: fix oops]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index b1063e9..52c54a5 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -352,7 +352,7 @@
 #define node_possible(node)	node_isset((node), node_possible_map)
 #define first_online_node	first_node(node_online_map)
 #define next_online_node(nid)	next_node((nid), node_online_map)
-int highest_possible_node_id(void);
+extern int nr_node_ids;
 #else
 #define num_online_nodes()	1
 #define num_possible_nodes()	1
@@ -360,7 +360,7 @@
 #define node_possible(node)	((node) == 0)
 #define first_online_node	0
 #define next_online_node(nid)	(MAX_NUMNODES)
-#define highest_possible_node_id()	0
+#define nr_node_ids		1
 #endif
 
 #define any_online_node(mask)			\