> where the number of padding locks is determined by how many lock
> structures fit within a 128 byte cache line.
>
> This isn't exactly elegant coding, but it provides a useful improvement
> on an 8-way SMP box when run on 8.0 base. OK, lets be brutal: this looks
> pretty darn stupid. But it does follow the CPU optimization handbook
> advice and I did see a noticeable improvement in performance and a
> reduction in context switching.
>
> I'm not in a position to try this again now on 8.1beta, but I'd welcome
> a performance test result from anybody that is. I'll supply a patch
> against 8.1beta for anyone wanting to test this.
>
I don't have an 8 way available right now but I can run tests on a 4 way
Opteron if that would be helpful.
Emil