Re: imapd.t failing on OpenBSD, bisects to 13a2088c74fd (kqnotify: drop EV_CLEAR (edge triggering))

[Eric Wong <e@80x24.org>]

Štěpán Němec <stepnem@smrk.net> wrote:
> On Wed, 18 Oct 2023 21:23:18 +0000
> Eric Wong wrote:
> 
> > Though I am curious if it's a red herring or not...  If you have
> > spare cycles to test on 7.3 or 7.4, it'd be greatly appreciated
> > (but no obligations to do so)
> 
> I downgraded the VM to 7.3, ran tests (this time updated to
> 848dedde919 (lei: simplify startq/au_done wakeup
> notifications), just with the EV_CLEAR re-removal on top),
> then upgraded to 7.4, ran tests.  I see the same failure
> pattern everywhere, so I really don't think the OpenBSD
> version is a factor here.

Thanks for the info.  Just curious, what HW specs (ncpus, RAM)
is available on that system?  I wonder if that affects timing
somehow...

> (And again, if you want to have a look yourself, I'd be
> happy to give you access to the machine; still the same
> testing OC VM.)

Unfortunately, my *BSD debugging knowledge is far behind my
Linux; so I'm not sure how much help it'd be...

Some examples of things I miss on OpenBSD:

* /proc/$PID/fdinfo/$FD_OF_EPOLL on Linux is immensely helpful
  for knowing what and how epoll is watching target FDs.  I'm
  not sure if there's a way to introspect kqueue like that

* Linux strace decodes more struct args info than kdump

* ability to control pathname of core dumps

... probably a few other things, but been sick a few days and
brain still foggy :<