[benlwalker]

There's one more aspect that I don't think gets enough consideration - you can batch many operations on different file descriptors into a single syscall. For example, if epoll is tracking N sockets and tells you M need to be read, you'd make M + 1 syscalls to do it. With io_uring, you'd make 1 or 2 depending on the mode. Note how it is entirely independent of either N or M.