Re: Strange issues with epoll since 5.0

[Eric Wong]

Eric Wong <e...@80x24.org> wrote:
> Deepa Dinamani <deepa.ker...@gmail.com> wrote:
> > I'm not sure what the hang in the userspace is about. Is it because
> > the syscall did not return an error or the particular signal was
> > blocked etc.
> 
> Uh, ok; that's less comforting.

Nevermind, I think I understand everything, now.  epoll_pwait
never set errno without our patch.

cmogstored does this in notify.c:

        /* wait_intr calls epoll_pwait: */
        mfd = mog_idleq_wait_intr(mog_notify_queue, timeout);
        if (mfd)
                notify_queue_step(mfd);
        else if (errno == EINTR) /* EINTR fails to be noticed */
                note_run();