x/sys/unix: add darwin efficiency core scheduling integer constants

[lattwood]

Proposal Details

Darwin has the ability to force scheduling to the efficiency cores on Apple Silicon through the setpriority syscall, but the integer constants currently aren't exposed.

I think changing the regex here: cs.opensource.google / github from PRIO_(PROCESS|PGRP|USER) to PRIO_(PROCESS|PGRP|USER|DARWIN_THREAD|DARWIN_PROCESS|DARWIN_BG|DARWIN_NONUI) or PRIO_(PROCESS|PGRP|USER|DARWIN_(THREAD|PROCESS|BG|NONUI)) would result in being able to force execution onto an efficiency core.

As an additional reference, here's the CPython PR: python/cpython#103545

I'd love to actually land this change in Go myself, but frankly don't know where to begin.

[ianlancetaylor]

Thanks. There is normally no need for a proposal to add support for a system call or system constants to x/sys/unix. Taking this out of the proposal process.

[lattwood]

@ianlancetaylor ahh, wasn't sure which was the right type