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

From: Jens Axboe
Date: Thu Jan 16 2020 - 11:30:17 EST


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!

--
Jens Axboe