RFR: 8362193: Re-work MacOS/AArch64 SpinPause to handle SB

[Evgeny Astigeevich]

On Mon, 21 Jul 2025 16:10:56 GMT, Andrew Haley <aph at openjdk.org> wrote:

> > > Do you not think we should implement the Arm-recommended solution in https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/multi-threaded-applications-arm?
> > 
> > 
> > When we get armv8.7 hardware, I'd like to try their solution.
> 
> OK, that makes sense.

In Apple Silicon CPU Optimization Guide I found M4 supports FEAT_SB (Armv8.5-A), FEAT_ECV (Armv8.6-A) and FEAT_WFxT (Armv8.7-A). I will try to get access to it to test the implementation.

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PR Comment: https://git.openjdk.org/jdk/pull/26387#issuecomment-3120128077