[ofw] [RFC] Locally generated path records

[Sean Hefty]

>Does RC require reversible paths ? Can't the two directions use
>different paths or is that only UD ?

The CM requires a reversible path for its MADs.  Additionally, neither the linux
nor windows CM _implementations_ support non-reversible path records.

>> I'm not sure that most MPI apps will run through an IB router, so always
>> querying for off subnet paths will probably be needed.
>
>That seems contradictory. Do you mean not needed rather than needed ?

I mean that all PRs that have endpoints on different subnets should be obtained
from the SA.  If PRs can be generated locally to a node, then the PRs should
only be generated if the destination is on the same subnet.

>>  (The current PR format
>> only works for UD traffic between IB subnets anyway.)
>
>Not sure why you say that.

Connected QPs require LID pairs for both subnets.  The PR only carries one of
the LID pairs.

- Sean