Hi Nikolay,
At the beginning of your post you wrote you are using "Intel Infiniband 2 ports controller and later on the dump (which i will assume taken from the same client) i see mlx4 mentioned which is the Mellanox adapter driver. can you clarify about your configuration?
Generally speaking, i can't recall seeing a lot of users doing NFSoRDMA. I've seen more users doing ipoib NFS. i suggest you try it first and see if things improves. other then that. i don't have anything smart to say but i will forward this on to folks who are more familiar with NFS...
Cheers!