Re: eventfd: socket does not allow changing to non-blocking

[Thomas Klausner <wiz%NetBSD.org@localhost>]

On Wed, Feb 16, 2022 at 05:47:59AM -0800, Jason Thorpe wrote:
> 
> > On Feb 16, 2022, at 1:51 AM, Thomas Klausner <wiz%NetBSD.org@localhost> wrote:
> > 
> > Hi!
> > 
> > NetBSD recently got an eventfd interface which is supposedly
> > compatible to Linux's.
> > 
> > net/zeromq uses eventfds and has lots of assertions in its test code,
> > and I looked at one of them. It basically makes a new eventfd and then
> > tries to set it to non-blocking mode using fcntl. This fails with
> > 'operation not supported'.
> > 
> > I see that eventfd() is documented as having a flag for non-blocking
> > mode when creating the eventfd, but since zeromq is doing this using
> > fnctl(), I guess this is supposed to work that way as well.
> > 
> > Is this a bug in NetBSD's eventfd implementation or is zeromq wrong
> > here?
> 
> Just a bug, I guess.  Will you file a PR?

Sure!

kern/56718: eventfd: fcntl(O_NONBLOCK) doesn't work
 Thomas