[tialaramex]

> with modern ISAs the core doesn't even spin.

Although tricks like PAUSE are much cheaper than a naive spinlock, they are still spinning as I understand it, just not as frantically because that's pointless and wasteful.

[dataangel]

It's even simpler than that, PAUSE just prevents the CPU from trying to speculatively execute across iterations.

[greatfilter251]

I'm not familiar with a pause instruction in a modern isa. Sounds like x86 crap.

I'm talking about wfi, wfe, and friends.