Re: [PATCH] libibverbs init.c: remove stderr warnings if no userspace driver found

Yann Droneaud
2015-05-11T21:32:42Z

Hi,

Le lundi 11 mai 2015 à 20:32 +0000, Jeff Squyres (jsquyres) a écrit :
> On May 9, 2015, at 8:04 AM, Yann Droneaud <ydroneaud-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org> wrote:
> >
> > Le vendredi 08 mai 2015 à 11:21 -0700, Jeff Squyres a écrit :
> >> Signed-off-by: Jeff Squyres <jsquyres-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> >
> > This is a little short for an explanation: what was the issue with the
> > error messages ?
>
> Cisco has stopped shipping its libibverbs usnic driver, although we
> are still using the kernel driver in the /sys/class/infiniband space
> (since it's the only way to be upstream). Specifically: instead of
> using libibverbs for userspace access, we are now using libfabric.
>

OK.

(I have to find some information about this libfabric which is already
released as 1.0.0 version).

> That is: it's not a warning or an error if libibverbs cannot find a
> userspace driver for kernel devices. Indeed, returning a num_devices
> of 0 is sufficient -- the middleware shouldn't be unconditionally
> printing out stderr message; let the upper layer application do that
> (if it wants to).
>

This paragraph should definitively be part of your commit message.

> FWIW, Sean just removed a similar set of stderr warnings from librdmacm:
>
> http://git.openfabrics.org/?p=~shefty/librdmacm.git;a=commitdiff;h=2b2aad809afc56fa3157f5cf99036f92b9c90f16
>

I don't think this a good thing to remove all the error messages
unconditionally. It could have been made a build option + an environment
variable option to help mere mortals to debug their setups.

Regards.

--
Yann Droneaud
OPTEYA