RFR: 8261447: MethodInvocationCounters frequently run into overflow [v2]

[Lutz Schmidt]

On Fri, 12 Feb 2021 08:29:37 GMT, Lutz Schmidt <lucy at openjdk.org> wrote:

>> I don't really like these .*64 suffixes. Can we just make the counter 64 bit, update the SA as Tobias suggested and keep the existing method names? Or is there a reason for doing this that eludes me?
>
> I introduced the *64 suffixes to not break anything that still uses the old calls. As old uses disappear step by step, I'm more than happy to remove the suffixes. I will have a look into SA and try to make it 64bit counter ready. There may be no new version before the weekend is over.

This is a request for help. Could someone with SA knowledge please check if my assumption is correct?

In hotspot code, the field Method::_compiled_invocation_count is annotated with a comment that it is used by SA. The field is also exposed via vmStructs.cpp to enable such use. I have scanned SA code in OpenJDK11 and OpenJDK head but found no evidence that this particular field is accessed. Is this finding/assumption correct? 

If so, I could just stop exposing the field, making my life easier. Thanks!

-------------

PR: https://git.openjdk.java.net/jdk/pull/2511