I do think it is different. In fact I think that IOCP predates the scheduler activation work. Certainly a proactor event loop (uring iocp) is different from a

I do think it is different. In fact I think that IOCP predates the scheduler activation work. Certainly a proactor event loop (uring iocp) is different from a reactor (poll) from an usage point of view, but you can implement one in term of the other. Scheduler activation is different and it is just a way for the kernel to notify userspace of all rescheduling events (including running out of the scheduling quantum or taking a page fault).