RFR: 8303210: [linux, Windows] Enable UseSystemMemoryBarrier by default if possible [v2]

[David Holmes]

On Sat, 25 Feb 2023 16:14:10 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> I'd like to enable UseSystemMemoryBarrier by default on supported Operating Systems in order to improve performance of thread state transitions (I/O, JNI, foreign function calls, JIT compiler threads, etc.). See JBS issue for more details.
>> Unfortunately, the feature was not yet implemented on all platforms. I added the code, but need the platform maintainers to check if it can be used reliably (and ideally if the performance improves). It's easy to switch it off again in case of problems.
>
> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix log message for platforms which don't support it.

I'm running a swag of our benchmarks on linux-x64 and linux-aarch64 with the flag simply set to true. Preliminary results show a big hit on startup benchmarks on both platforms!

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PR: https://git.openjdk.org/jdk/pull/12753