diff --git a/tools/testing/radix-tree/linux/radix-tree.h b/tools/testing/radix-tree/linux/radix-tree.h
index ce694dd..f4d8532 100644
--- a/tools/testing/radix-tree/linux/radix-tree.h
+++ b/tools/testing/radix-tree/linux/radix-tree.h
@@ -1 +1,18 @@
+#ifndef _TEST_RADIX_TREE_H
+#define _TEST_RADIX_TREE_H
 #include "../../../../include/linux/radix-tree.h"
+
+extern int kmalloc_verbose;
+
+static inline void trace_call_rcu(struct rcu_head *head,
+		void (*func)(struct rcu_head *head))
+{
+	if (kmalloc_verbose)
+		printf("Delaying free of %p to slab\n", (char *)head -
+				offsetof(struct radix_tree_node, rcu_head));
+	call_rcu(head, func);
+}
+#undef call_rcu
+#define call_rcu(x, y) trace_call_rcu(x, y)
+
+#endif /* _TEST_RADIX_TREE_H */