Kanevsky, Arkady wrote:
Sean, SWG discussed today the extending private data format proposal to SIDR_REQ. The group does not see the need for it since ULP is no RDMA aware. That is ULP does not use RDMA operations. Do you have some specific ULP in mind for this functionality? For UDP a different IP address can be used for each message. There is no persistent connection.
I didn't have any particular ULP in mind. I was thinking more of a generic application that wanted to use UDP style addressing over IB, similar to what's being discussed for using TCP style addressing over IB.
It seems that there needs to be a way to map a given destination address to a remote QP/qkey. Regardless if the IP address is carried in each ULP message, it would still need to be in the SIDR REQ in order to locate the correct QP.
Such a ULP won't use RDMA or atomic operations, but still benefits by having QP and CQ semantics, such as direct hardware access from userspace and pre-posted receive buffers, while avoiding the overhead of IP (or IPoIB). So, I would consider the application as being "RDMA aware", with "RDMA" hardware defined as that which provides QP semantics. I view it similar to applications that sit over DAPL that do only sends and receives.
In any case, this can be treated as a separate issue than what's being defined for connections. It could just be beneficial that if it is ever defined that it use the same private data format.
- Sean _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
