Re:Towards fearless SIMD, 7 years later
by zozbot234 on Sunday March 30, 2025 @12:41PM
(#43525476)
> Atomics are very expensive operations.
Atomics are very expensive when contended - which is also the case where locks would introduce blocking and reduced performance. Uncontended atomics are relatively cheap.
Re:Towards fearless SIMD, 7 years later
by pclmulqdq on Sunday March 30, 2025 @01:11PM
(#43525726)
I suggest you run a microbenchmark. Uncontended atomics are some of the most expensive assembly instructions out there. They also acquire global system locks on certain stages of execution.
Atomics are very expensive when contended - which is also the case where locks would introduce blocking and reduced performance. Uncontended atomics are relatively cheap.