[ofa-general] OFED 1.4's autoconf.h conflicting with kernel

[Brian J. Murrell]

On Fri, 2009-01-23 at 11:01 -0800, Jeff Becker wrote:
> Hi Brian

Hi (again) Jeff (and everyone else, especially however maintains the
packaging of /usr/src/ofa_kernel),

> Brian J. Murrell wrote:
> >
> > Some research has led me to a message
> > (http://www.mail-archive.com/general@lists.openfabrics.org/msg18161.html) from Jeff Becker back on Thu, 10 Jul 2008 15:58:53 -0700 in which he submitted a patch to integrate NFSRDMA into OFED 1.4 which is what appears to have brought these changes into OFED 1.4.

The more I look at this, the more I'm convinced there is either an angle
I am completely missing or this is just plainly not the way to do this.

It just cannot work to have two "linux/autoconf.h" files for a third
(where the first two parties are OFED and the kernel) party module
build.  There is no guarantee that the third party module won't need to
query about various CONFIG_ definitions of both the kernel and the OFED
stack.

The only way I can think of making this work is to "somehow" "unionize"
these two files (i.e. so there is a single "superset" of them both).
Perhaps it's doable with some kind of #include_next magic, perhaps not.

> I usually build my kernel first (usually with NFS). Then I build OFED.

Right.  This is simple enough.  It's when you want to build another
kernel module that wants the OFED stack that things get sticky.

I realize this is probably not really your area of responsibility and
this dual autoconf.h problem pre-existed your patch, but your patch has
really exacerbated the issue by directly conflicting (CONFIG_SYSCTL is
the particular example I have on hand at the moment) some of the non-IB
kernel defines.

I'd love to engage whoever is directly responsible for this area of the
stack but nobody seems to be responding to my queries or the bug which I
filed yesterday (which is admittedly a short time ago).  I'd try just
posting a patch to fix it, but I think this needs some discussion on how
to really achieve the end goal.

Cheers,
b.