[openib-general] mthca FMR correctness (and memory windows)

[Vu Pham]

> As to using FMRs to create virtually contiguous regions, the last data
> I saw about this related to SRP (not on OpenIB), and resulted in a
> gain of ~25% in throughput when using FMRs vs the "full frontal" DMA
> MR.  So there is definitely something to be gained by creating
> virutally contiguous regions, especially if you're doing a lot of RDMA
> reads for which there's a fairly low limit to how many can be in
> flight (4 comes to mind).
> 

Since the NFS server have to do all the RDMA READ/WRITE 
operations, you can help to reduce the work load / cpu util 
/ resources for the NFS server per client (one single 64KB 
RDMA RD/WR comparing to 16x4KB RDMA RD/WR) by doing FMRs on 
the clients


Vu