On Wed, Jun 1, 2022 at 11:21 AM Jens Axboe <axboe@xxxxxxxxx> wrote: > > Of the added opcodes in io_uring, that one I'm actually certain never > ended up getting used. I see no reason why we can't just deprecate it > and eventually just wire it up to io_eopnotsupp(). > > IOW, that won't be the one holding us back killing epoll. That really would be lovely. I think io_uring at least in theory might have the potential to _help_ kill epoll, since I suspect a lot of epoll users might well prefer io_uring instead. I say "in theory", because it does require that io_uring itself doesn't keep any of the epoll code alive, but also because we've seen over and over that people just don't migrate to newer interfaces because it's just too much work and the old ones still work.. Of course, we haven't exactly helped things - right now the whole EPOLL thing is "default y" and behind a EXPERT define, so people aren't even asked if they want it. Because it used to be one of those things everybody enabled because it was new and shiny and cool. And sadly, there are a few things that epoll really shines at, so I suspect that will never really change ;( Linus