UseAdaptiveSizePolicy and other jvm opts

Question

The JVM option -XX:+UseAdaptiveSizePolicy is defined as part of the hotspot ergonomics and can be specified with throughput or the pause time priority.

However, my q

Answer 1

Just FYI, -XX:+UseAdaptiveSizePolicy is enabled by default in any recent version of the Sun JVM.

Also, I found an article:

Avoid trouble: -XX:SurvivorRatio= option is incompatible with the JVM parameter -XX:+UseAdaptiveSizePolicy. Please use either one according to your situation.

I couldn't find a definitive answer for NewSize, but it appears it sets the initial young generation size, not permanent, so it's not mutually exclusive with UseAdaptiveSizePolicy.

However, here's a bunch of articles:

• http://download.oracle.com/javase/1.5.0/docs/guide/vm/gc-ergonomics.html
• http://www.oracle.com/technetwork/java/gc-tuning-5-138395.html
• http://developers.sun.com/mobility/midp/articles/garbagecollection2/

In most cases, however, if you're tuning SurvivorRatio will want to tune NewSize and MaxNewSize.