RFR: 6942632: Hotspot should be able to use more than 64 logical processors on Windows [v7]

[Saint Wesonga]

On Mon, 4 Mar 2024 06:49:52 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Shouldn't the check for a job object be unconditional? I don't understand what the connection is to either `UseAllWindowsProcessorGroups` or the Windows version here. ??

A job object can enable multiple Windows processor groups. I think running with -XX:-UseAllWindowsProcessorGroups should override the job object enabling processors in >1 processor group (closer to behavior that would be seen in older OpenJDK versions). The approach I've taken adds a warning when this happens. Other than that, I've updated the implementation to respect the number of processors enabled by the job object. On older Windows versions, this includes displaying a warning that only 1 processor group is supported. Please let me know what you think of this approach.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17576#discussion_r1524011699