Re: Improving spin-lock implementation on ARM.

Alexander Korotkov <aekorotkov(at)gmail(dot)com> writes:
> On Fri, Nov 27, 2020 at 1:55 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> ... and, after retrieving my jaw from the floor, I present the
>> attached. Apple's chips evidently like this style of spinlock a LOT
>> better. The difference is so remarkable that I wonder if I made a
>> mistake somewhere. Can anyone else replicate these results?

> Results look very surprising to me. I didn't expect there would be
> any very busy spin-lock when the number of clients is as low as 4.

Yeah, that wasn't making sense to me either. The most likely explanation
seems to be that I messed up the test somehow ... but I don't see where.
So, again, I'm wondering if anyone else can replicate or refute this.
I can't be the only geek around here who sprang for an M1.

regards, tom lane