Re: [GIT PULL] io_uring updates for 5.18-rc1

[Linus Torvalds <torvalds@linux-foundation.org>]

On Wed, Jun 1, 2022 at 11:21 AM Jens Axboe <axboe@kernel.dk> 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