Current GHA runs both Mac x86 and Mac AArch64 build and test jobs. Mac x86 was here from day 1, and Mac AArch64 was added with JDK-8325194 in early 2024.

The world seems to have moved to M1/2/3 chips for Mac platforms. Lots of OpenJDK developers on Macs likely have AArch64 machines now.

In GHA infrastructure, the latest runners available for Mac x86 are macos-13. macos-14 and macos-15 are not available for standard Mac x86 runners: https://github.com/actions/runner-images?tab=readme-ov-file#available-images. GH seem to have no plans for introducing Mac x86 runners for newer MacOS-es: https://github.com/actions/runner-images/issues/9741#issuecomment-2075259811.

AFAIU, MacOS 13 will EOL 3 years after release, so around Oct 2025. I expect the availability for macos-13 runners for x86 to gradually decrease well before that. I have anecdotal evidence that often the GHA testing for my PRs is waiting on Mac x86 runners to pick up test jobs.

I think we are at the point when we can and should stop testing Mac x86 in GHA, demoting this platform to build only. In future, we would likely remove the build jobs as well.