[ofa-general] RDMA over infiniband, diffrences between rdam_cm and libmthca-rdmav2

[Sean Hefty]

>I am new in infiniband, and I am doing some research on rdma.
>I have found two diffrents way of sending data on infiniband protucts
>using rdma.
>The first one use rdam_cm module (from kernel source code), and second
>one use  libmthca-rdmav2/libibverbs.
>
>If someone can explain me the diffrences between this two types of programming.

The library to send data is libibverbs.  The rdma_cm (or librdmacm) is one
method that can be used to setup the QPs for communication.  I.e. exchange the
QP numbers, LIDs, etc.  You could also setup the QPs using the libibcm or just
exchange the data over a standard socket.  If you look at the librdmacm code,
you will see that it calls the libibverbs functions to allocate and modify the
QP.

- Sean