> What do you mean by this?

OP's comment is n the context of an article describing extensions to AIO to support polling, one of the benefits of that mechanism is a single call can submit new IO operations simultaneous to registering readiness notifications. AFAIK neither epoll nor kqueue support that

Thanks for weighing in, plenty to digest here

Re: epoll-on-fork, do you mean the behaviour where it associates with the wrong kernel object? I knew about that one, although fork sounds curious, but I think you're probably just referring to the trouble fd leaks can cause due to the former issue