> -----Original Message----- > From: Christoph Hellwig [mailto:[EMAIL PROTECTED] > Sent: Thursday, June 30, 2005 9:03 AM > To: Caitlin Bestler > Cc: openib-general; [EMAIL PROTECTED] > Subject: Re: [openib-general] Making gen2 transport neutral > > On Thu, Jun 30, 2005 at 08:52:54AM -0700, Caitlin Bestler wrote: > > structs: > > typically "struct ib_xyz" is transformed as follows: > > > > struct ib_xyz { > > /* Only IB specific fields remain */ > > /* In some cases fields have been split, because > > * iWARP allows two things to vary that IB had > > * locked together. SGE limits are the primary > > * example of this. iWARP can have different > > * limits on SGE size for each type of message > > */ > > }; > > > > struct iwarp_xyz { > > /* equivalent iWARP specific fields */ > > }; > > > > struct rdma_xyz { > > /* Transport neutral fields. Typically > > * a subset of what was in struct ib_xyz before > > */ > > union { > > struct ib_xyz ib; > > struct iwarp_xyz iwarp; > > } xpt; > > }; > > wrong way around, but we had that before. It should be > > struct ib_foo { > struct rdma_foo common; > ... > } > > struct iwarp_foo { > struct rdma_foo common; > ... > } >
That's a style question that I've heard both opinions on. I'm comfortable with either approach, and actually prefer the one you are suggesting. But I've ususally been on the losing side of those discussions (not that I care strongly either way). If there's a citation in coding standards somewhere that makes this a closed issue please cite it. That would close the discussion quickly. If there isn't a solid rule it really comes down to a question of how likely a new RDMA transport is that is not based upon either IB or iWARP. I doubt it. iWARP differs from IB because it *had* to in order to ride over TCP/IP and SCTP. IB has assumptions that are only possible when the tranport and RDMA layers are intergrated and share acknowledgement messages. For iWARP to emulate that would have required redundant ack messages that would have cluttered the network. _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general