On 12/15/19 8:48 AM, Pavel Begunkov wrote: > On 15/12/2019 08:42, Jens Axboe wrote: >> On 12/14/19 11:43 AM, Jens Axboe wrote: >>> On 12/14/19 7:53 AM, Pavel Begunkov wrote: >>>> There is no reliable way to submit and wait in a single syscall, as >>>> io_submit_sqes() may under-consume sqes (in case of an early error). >>>> Then it will wait for not-yet-submitted requests, deadlocking the user >>>> in most cases. >>>> >>>> In such cases adjust min_complete, so it won't wait for more than >>>> what have been submitted in the current call to io_uring_enter(). It >>>> may be less than totally in-flight including previous submissions, >>>> but this shouldn't do harm and up to a user. >>> >>> Thanks, applied. >> >> This causes a behavioral change where if you ask to submit 1 but >> there's nothing in the SQ ring, then you would get 0 before. Now >> you get -EAGAIN. This doesn't make a lot of sense, since there's no >> point in retrying as that won't change anything. >> >> Can we please just do something like the one I sent, instead of trying >> to over-complicate it? >> > > Ok, when I get to a compiler. Great, thanks. BTW, I noticed when a regression test failed. -- Jens Axboe
