Nope on all modern CPUs (X86 and ARM) this is 64 bytes and has been since a looo...

astrange · on Dec 23, 2022

Cache lines are 128 bytes on M1.

But since it’s AMP and not SMP, sharing work across cores doesn’t necessarily work how you expect it to.

bullen · on Dec 23, 2022

Can you ask the OS to give you a certain core type?

128 bytes is perfect 2 x 64! So even if the risk of cache invalidation goes up even if two cores are not writing to the exact same structure the alignment still works!

Good job Apple!

fisf · on Dec 23, 2022

There absolutely are modern systems that have e.g. 128 byte cache lines (M1).