> requiring you to waste cpu cycles in a polling loop checking if an fd is "ready", epoll in edge-triggered mode does not require this loop to exist in userlan

> requiring you to waste cpu cycles in a polling loop checking if an fd is "ready", epoll in edge-triggered mode does not require this loop to exist in userland. In edge-triggered epoll (or the similar kqueue construct), your work thread(s) will be asleep until the kernel chooses to wake one up.