I want to understand more about the point 'lock contention' in the free memory list. In your case, you have 1GB Heap, with 4 cores. So, assume your young gen size is 100MB, the old gen is around 900MB. So each core will share 900MB / 4 = around 225MB. If I can use 8 cores, each core will share 113MB. Lock contention occurs because each thread is working on 'Too few' old gen size? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4240193#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...