On Wed, Dec 02, 2009 at 12:38:31PM +0200, Liran Liss wrote: > > > So? There are substantial semantic differences for *all* non-rdmacm > > applications. Even common ones like OpenMPI. You propose to ignore them? > > On the contrary! Any application that *does* care what the link layer is > can look up a new field in port_attr (rather than a new node transport > type). > Applications that don't, both old and new, can continue as normal - no > changes to the code are required.
Existing apps rely on transport_type == IBV_TRANSPORT_IB to indicate IB management is present. There are many examples of this. The art of API compatability is to not break existing old apps, so you don't get to change the meaning of transport_type == IBV_TRANSPORT_IB to mean 'it is only IB verbs like'. That breaks the API. Adding a new field to port_attr preserves functionality but not compatability. I hope you understand the difference. > So, all relevant apps will work great with either IB or RDMAoE, in a > transparent manner. No, they won't. They will see transport_type == IBV_TRANSPORT_IB and attempt to do PR queries to the SM. That won't work on RDMAoE. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
