I don't think that I can actively hack on the JVM, but I can tell you that XPerf is a great way to determine where you're spending your time. http://www.microso

I don't think that I can actively hack on the JVM, but I can tell you that XPerf is a great way to determine where you're spending your time. http://www.microsoftpdc.com/2009/CL16 http://www.microsoftpdc.com/2009/CL16 is a really good intro video on the topic, it's a very powerful tool (though doesn't provide as much analysis as Instruments for example)