NFS + Infiniband problem

[Rick Macklem]

[stuff related to slow performance snipped]
Try disabling TSO, that is the most common cause of NFS RPC
transport issues.
# sysctl net.inet.tcp.tso=0
will do it, if you can't do it for the interface.
(Also, try disabling LSO, LRO if the interface will let you do so.)

You can also try mounting with "rsize=8192,wsize=8192" and if that works
fairly well, then just keep doubling it until it no longer works well.

I know nothing about InfiniBand, so if the above doesn't help, hopefully
someone familiar with InfiniBand can help.

Good luck with it, rick