[ofa-general] Re: How to tell what OFED rev a distro derived IB modules?

[Jason Gunthorpe]

On Sun, Apr 26, 2009 at 02:31:18PM +0300, Jack Morgenstein wrote:
> On Friday 24 April 2009 02:48, Jason Gunthorpe wrote:
> > AFAIK, Ubuntu does not do any work on their IB drivers, so the driver
> > is stock 2.6.27.
> > 
> > In principle OFED is supposed to start with an upstream kernel and
> > backport those drivers to various distributions. OFED 1.3 was using
> > 2.6.24, OFED 1.4 is apparently using 2.6.27.
> > 
> > So it should be similar to OFED 1.4
> > 
> > Though bear in mind OFED still patches things with stuff that is not
> > yet accepted upstream so there will be some differences.
> > 
> > It should be compatible with the OFED 1.4 userspace.
> > 
> Beware -- you should not use OFED userspace with a non-ofed kernel for ConnectX HCAs.
> The OFED 1.4 ConnectX driver includes the XRC (Extended RC) patches -- which grab
> 23 (the MSB) of the QP number to indicate an XRC SRQ in CQEs.  Non-OFED kernels do not
> reserve bit 23 for this usage, so you will experience incompatibility problems.
> 
> In general, you should not use OFED userspace libraries with non-OFED kernel distributions.

That is hugely unfriendly and not really 'the linux way'..

Jason