Erlang gives a reductions budget to processes. After a certain number of reductions, or if a process hits a yield point (like waiting to receive a message), the

Erlang gives a reductions budget to processes. After a certain number of reductions, or if a process hits a yield point (like waiting to receive a message), the process will yield allowing another process to run. Go uses preemption now (since 1.14), but it didn't always. It used to be that you could use a busy loop and that goroutine would never yield. Yield points include things like function entries, syscalls, and a few other points.