x86: not set node to cpu_to_node if the node is not online

resolve boot problem reported by Mel Gorman:

   http://lkml.org/lkml/2008/2/13/404

init_cpu_to_node will use cpu->apic (from MADT or mptable) and
apic->node(from SRAT or AMD config space with k8_bus_64.c) to have
cpu->node mapping, and later identify_cpu will overwrite them
again...(with nearby_node...)

this patch checks if the node is online, otherwise it will not
update cpu_node map. so keep cpu_node map to online node before
identify_cpu..., to prevent possible error.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/mm/numa_64.c

@@ -622,13 +622,17 @@ void __init init_cpu_to_node(void)
 	int i;
 
 	for (i = 0; i < NR_CPUS; i++) {
+		int node;
 		u16 apicid = x86_cpu_to_apicid_init[i];
 
 		if (apicid == BAD_APICID)
 			continue;
-		if (apicid_to_node[apicid] == NUMA_NO_NODE)
+		node = apicid_to_node[apicid];
+		if (node == NUMA_NO_NODE)
 			continue;
-		numa_set_node(i, apicid_to_node[apicid]);
+		if (!node_online(node))
+			continue;
+		numa_set_node(i, node);
 	}
 }