epoll_register_kevent
if (epoll_register_kevent(td, epfp, fd, EVFILT_READ, 0) != ENOENT ||
epoll_register_kevent(td, epfp, fd, EVFILT_WRITE, 0) != ENOENT)
error1 = epoll_register_kevent(td, epfp, fd, EVFILT_READ, EV_DELETE);
error2 = epoll_register_kevent(td, epfp, fd, EVFILT_WRITE, EV_DELETE);
static int epoll_register_kevent(struct thread *td, struct file *epfp,