Re: [PATCH] io_uring: wakeup threads waiting for EPOLLOUT events

From: Stefano Garzarella
Date: Thu Jan 16 2020 - 12:03:59 EST


On Thu, Jan 16, 2020 at 09:30:12AM -0700, Jens Axboe wrote:
> On 1/16/20 9:26 AM, Stefano Garzarella wrote:
> >> Since the use case is mostly single submitter, unless you're doing
> >> something funky or unusual, you're not going to be needing POLLOUT ever.
> >
> > The case that I had in mind was with kernel side polling enabled and
> > a single submitter that can use epoll() to wait free slots in the SQ
> > ring. (I don't have a test, maybe I can write one...)
>
> Right, I think that's the only use case where it makes sense, because
> you have someone else draining the sq side for you. A test case would
> indeed be nice, liburing has a good arsenal of test cases and this would
> be a good addition!

Sure, I'll send a test to liburing for this case!

Thanks,
Stefano