--- zzzz-none-000/linux-2.6.28.10/kernel/rcupreempt.c	2009-05-02 18:54:43.000000000 +0000
+++ puma5-6360-529/linux-2.6.28.10/kernel/rcupreempt.c	2009-06-04 07:28:46.000000000 +0000
@@ -1108,6 +1108,7 @@
 
 void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
 {
+    printk("call_rcu executed by pid=%i\n", current->pid);
 	unsigned long flags;
 	struct rcu_data *rdp;