diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index a4c592b66e10b7cee1fadf6ff93e42bd62d8f695..0fdbc5e0730234b124bd098c01a7eed2a717f76d 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -2675,7 +2675,7 @@ static void __init rcu_init_geometry(void)
 {
 	int i;
 	int j;
-	int n = NR_CPUS;
+	int n = nr_cpu_ids;
 	int rcu_capacity[MAX_RCU_LVLS + 1];
 
 	/* If the compile-time values are accurate, just leave. */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 70e0fd256cc6b824453cad62d1b1cfdb83df3f5c..ef2b5231afa41120d3c8a12f3fb8826717d7b26c 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -72,6 +72,8 @@ static void __init rcu_bootup_announce_oddness(void)
 #endif
 	if (rcu_fanout_leaf != CONFIG_RCU_FANOUT_LEAF)
 		printk(KERN_INFO "\tExperimental boot-time adjustment of leaf fanout to %d.\n", rcu_fanout_leaf);
+	if (nr_cpu_ids != NR_CPUS)
+		printk(KERN_INFO "\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids);
 }
 
 #ifdef CONFIG_TREE_PREEMPT_RCU