> In order for the patch to be able to move ahead, we'd need to be able > to control this behavior. Right now we rely on the file being there if > we need to repoll, see: > > commit a6ba632d2c249a4390289727c07b8b55eb02a41d > Author: Jens Axboe <axboe@xxxxxxxxx> > Date: Fri Apr 3 11:10:14 2020 -0600 > > io_uring: retry poll if we got woken with non-matching mask > > If this never happened, we would not need the file at all and we could > make it the default behavior. But don't think that's solvable. > > > is there no other way around to close the file descriptor? Even if I > > remove the poll, it doesn't work > > If you remove the poll it should definitely work, as nobody is holding a > reference to it as you have nothing else in flight. Can you clarify what > you mean here? > > I don't think there's another way, outside of having a poll (io_uring > or poll(2), doesn't matter, the behavior is the same) being triggered in > error. That doesn't happen, as mentioned if you do epoll/poll on a file > and you close it, it won't trigger an event. > > > btw if understood correctly poll remove operation refers to all file > > descriptors which arming a poll in the ring buffer right? > > Is there a way to cancel a specific file descriptor poll? > > You can cancel specific requests by identifying them with their > ->user_data. You can cancel a poll either with POLL_REMOVE or > ASYNC_CANCEL, either one will find it. So as long as you have that, and > it's unique, it'll only cancel that one specific request. thanks it works, my bad, I was not aware that user_data is associated with the poll request user_data...just need to remove my server socket poll which binds to an address so I think this patch is not really necessary btw IORING_FEAT_FAST_POLL feature which arming poll for read events, how does it work when the file descriptor(not readable yet) wants to read(non blocking) something and I close(2) the file descriptor? I'm guessing io_uring doesn't hold any reference to it anymore right? --- Josef Grieb
