CMSPermGenSweepingEnabled vs CMSClassUnloadingEnabled

Question

I\'ve kind of asked this question before - What does JVM flag CMSClassUnloadingEnabled actually do?, but this time it\'s slightly different!

If I start a Java VM wit

Answer 1

From what I can tell, the only thing that the 1.6 JVM does with CMSPermGenSweepingEnabled is to print that message - it's not processed the way it is in 1.5. For CMSClassUnloadingEnabled to have any impact, UseConcMarkSweepGC must also be set.