RFR: 8316813: NMT: Using WhiteBox API, virtual memory tracking should also be stressed in JMH tests [v2]

[Thomas Stuefe]

On Thu, 1 Feb 2024 18:26:16 GMT, Afshin Zafari <azafari at openjdk.org> wrote:

>> After WhiteBox (`wb.jar`) is added to the lib-test, it is possible to use it in Java benchmarks. This PR uses WhiteBox to access and call directly NMT API and measure their performance in stressed circumstances.
>
> Afshin Zafari has updated the pull request incrementally with one additional commit since the last revision:
> 
>   better names for variables used.

I wonder, though, how much value this benchmark really has. Since we now measure both the mmap call and the registration with NMT. The mmap call may dominate, and/or bring a lot of randomness, since it depends on the context (e.g. do we swap, do we have pages in cache etc).

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PR Comment: https://git.openjdk.org/jdk/pull/17582#issuecomment-1938717389