diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6b8889d..c623e0c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2056,6 +2056,7 @@
 }
 EXPORT_SYMBOL_GPL(free_vm_area);
 
+#ifdef CONFIG_SMP
 static struct vmap_area *node_to_va(struct rb_node *n)
 {
 	return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
@@ -2336,6 +2337,7 @@
 		free_vm_area(vms[i]);
 	kfree(vms);
 }
+#endif	/* CONFIG_SMP */
 
 #ifdef CONFIG_PROC_FS
 static void *s_start(struct seq_file *m, loff_t *pos)