On Fri, Jan 11, 2019 at 05:11:57PM +0100, Ilya Dryomov wrote: > I think you can use the new IOCB_CMD_POLL from Christoph and avoid > epoll_wait() in favor of aio/io_uring interface, at least in new high > performance applications. Reaping events entirely in userspace (i.e. > performing io_getevents() without entering the kernel) has been > possible for a long time even with the existing aio interface. For io_uring we can reuse the IOCB_CMD_POLL concept, but we'd have to add a new cancel command, as the uring right now doesn't support cancelation. But I'd rather make that command a new opcode instead of a separate syscall, which would lead to a nicer design. A prototype for this should be fairly easy, I'd just want someone to actually use it for real life testing, like ScyllaDB does for IOCB_CMD_POLL.