[openib-general] cma private data length

[Steve Wise]

Sean/IB experts:

I'm running a version of rdma_bw from src/userspace/perftest that I
ported to utilize the RDMA CMA library for connection setup (stay tuned
for a patch to offer this to the trunk).  The CMA version exchanges the
rkey information during RDMA connection setup using private data.  I
noticed that over IB the private data length received is != to the size
of the private data submitted by the application.  I send 24 bytes both
ways and always get 56 bytes in the RDMA_CM_EVENT_CONNECT_REQUEST event
and 196 bytes on the RDMA_CM_EVENT_ESTABLISHED event.  The first 24
bytes, however, are correct so the data is being exchanged.  Over iWARP,
the lengths are 24...

Is this a bug in the CMA or IB CM? 

Thanks,

Steve.