Making PrintEscapeAnalysis a diagnostic option on product VM?

Chris Newland cnewland at
Fri Jun 19 10:16:24 UTC 2015

Hi, hope this is the correct list (perhaps serviceability?)

I'm experimenting with some HotSpot changes that log escape analysis
decisions so that I can visualise eliminated allocations at the source and
bytecode levels in JITWatch[1].

My plan was to build a companion VM for JITWatch based on the product VM
that would allow users to inspect some of the deeper workings such as EA
and DCE that are not present in the LogCompilation output.

I mentioned this to some performance guys at Devoxx and they didn't like
the custom VM idea and suggested I put in a request to consider making
-XX:+PrintEscapeAnalysis available under -XX:+UnlockDiagnosticVMOptions on
the product VM (it's currently a notproduct option).

If this is something you would consider than could I also request
consideration of -XX:+PrintEliminateAllocations.

All I would need is the class, method, and bci of each NoEscape detected.

Kind regards,



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