RFR: 8261229: MethodData is not correctly initialized with TieredStopAtLevel=3

[Igor Ignatyev]

On Sat, 6 Feb 2021 06:16:45 GMT, Igor Veresov <iveresov at openjdk.org> wrote:

> Mostly a typo in compilation mode ergonomics that selected a quick-only mode essentially when the user specified TieredStopAtLevel={1,2,3}. The quick-only mode has an optimization that eliminates parts of the MDO since they are not needed. Meanwhile, the WB API considered it a fair game to request a level 3 compile, that requires a full MDO.
> 
> The fix corrects the original issue and also tries to be extra defensive with WB API (since it's semantics is not clearly specified) by always allocating full MDO if WB API is on.

I don't think we should adjust the product code to behave differently just to satisfy the incorrect assumptions of WhiteBox. it also kinda defeats the purpose of WhiteBox API as we won't be able to go thru the same code path.

-- Igor

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PR: https://git.openjdk.java.net/jdk/pull/2444