pcsx2 VMManager: MacOS CPU count detection

Add CPU count detection for macOS Fixes #8585

So M1 users don't keep coming to us with performance issues because they have MTVU off

Note: cpuinfo prefers relying on cpuid over sysctl, which makes it misdetect M1s in Rosetta as 8 symmetric cores, so we're skipping cpuinfo on macOS.

Reset to default settings and see if MTVU is enabled

Apr 11 '23 01:04 TellowKrinkle

LGTM, tested M1, and intels with 2c/4t and 6c/12t

Apr 11 '23 02:04 DigitalMajestic

Wondering if this would be better placed in the Darwin directory in common.

Apr 11 '23 02:04 stenzek

Wondering if this would be better placed in the Darwin directory in common.

Like just put the macOS specific code there, or add a cpu detection header and move all the cpu detection (+ affinity setting?) there?

May 10 '23 23:05 TellowKrinkle

Was just thinking abstract the routine to get the big/small core count (i.e. the sysctl stuff).

May 11 '23 04:05 stenzek

@DigitalMajestic Could you test again and make sure it still works?

May 13 '23 21:05 TellowKrinkle

LGTM

May 15 '23 21:05 DigitalMajestic