The OFED has support of new memory registration mechanisms that the o2iblnd currently don't use.

• IB_WR_FAST_REG_MR: work request based asynchronous memory registration. It removes memory registration out of the critical path and has the potential of improving throughput.
• IB_WR_REG_INDIR_MR: allows registration of non-page aligned memory fragments. See:
  https://www.mail-archive.com/linux-rdma@vger.kernel.org/msg21430.html

The 1st one may improve throughput and the 2nd one may solve the long-standing issue of "too many RDMA frags" failures we had (forgot which ticket, Liang?).

We should do some investigation and decide whether to add support of these OFED features to the o2iblnd.