Lock contention over common object, such as the free memory list? I really have not had time to investigate it. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4239776#4239776 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=4239776