How Rust optimizes async/await
As a reminder, you don't need to use async/await to implement socket servers in Rust. You can use threads, and they scale quite well. M:N scheduling was found to be slower than 1:1 scheduling on Linux, which is why Rust doesn't use that solution.Async/await is a great feature for those who require performance beyond what threads (backed by either 1:1 or M:N implementations) can provide. One of the major reasons behind the superior performance of async/await futures relative to threads/goroutines/etc. is that async/await compiles to a state machine in the manner described in this post, so a stack is not needed.