====== GC in jboss-cli ======
''cd'' to the directory of your jboss's bin, and run
<code>
jboss-cli
connect
/core-service=platform-mbean/type=memory:gc
exit
</code>
You might also want to query the memory usage before and after the GC by 
<code>
/core-service=platform-mbean/type=memory:query
</code>