Add an API to allow getting the number of "performance" cores-only

Feature or enhancement

Proposal:

Currently Python provides os.cpu_count() which returns the total number of physical CPU cores.

On macOS M-class machines (and probably other ARM hardware), there are actually two types of CPU cores: performance cores, and efficiency cores.

For many tasks where a user wants to do "1 task per core", it really only makes sense to do 1 task per performance core.

Therefore it'd be sensible to expose this number. On macOS it can be found with the hw.perflevel0.logicalcpu sysctl.

This could be done in one of two ways, a new function, e.g. os.performance_cpu_count(), or as a keyword-argument to os.cpu_count(performance_cores_only=True).

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

まず既存の os.cpu_count() API とプラットフォーム固有の実装を読み、次に提案で説明されている macOS の hw.perflevel0.logicalcpu sysctl を調査します。サポート対象のプラットフォーム全体で、新しい関数とキーワード引数の選択肢を比較し、関連するテストを特定します。選択した API が、サポート対象システムについて文書化された動作とカバレッジを備え、パフォーマンスコア数を確実に公開できれば完了です。