diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 1a9ef3e..5dce5c2 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -352,6 +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);
 #else
 #define num_online_nodes()	1
 #define num_possible_nodes()	1
@@ -359,6 +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
 #endif
 
 #define any_online_node(mask)			\
diff --git a/lib/cpumask.c b/lib/cpumask.c
index 3a67dc5..7a2a73f 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -43,3 +43,19 @@
 	return cpu;
 }
 EXPORT_SYMBOL(__any_online_cpu);
+
+#if MAX_NUMNODES > 1
+/*
+ * Find the highest possible node id.
+ */
+int highest_possible_node_id(void)
+{
+	unsigned int node;
+	unsigned int highest = 0;
+
+	for_each_node_mask(node, node_possible_map)
+		highest = node;
+	return highest;
+}
+EXPORT_SYMBOL(highest_possible_node_id);
+#endif