[ofw] [RFC] Locally generated path records

[Sean Hefty]

>Yeah, it's a shame the maintainers for OpenSM on Windows are MIA.  It's
>probably been a year since Windows OpenSM has been synchronized with Linux
>OpenSM.

Once winmad and libibumad are working, it will hopefully be easier to keep the
windows and linux code bases in sync.  The goal would be to keep a single code
repository for diags and opensm, rather than continually porting them into a
separate repository and having to maintain it.

>So the MC group static rate would be the floor for communication for anyone in
>the group then.  That does what I need it to then.

You could probably read the port attributes to determine the rate.  It may not
work on the far side, but I would think that you could discover that through the
CM protocol.

>So path records for UD and RC don't need to be reversible?  Is zero thus a
>better hard coded value?

Well... you need someway for the remote side to send data back.  Setting
reversible = 1 likely works in practice for most configurations.  The CM
requires a reversible path for the CM messages.

I don't know of any apps that actually make use of non-reversible paths.  Maybe
ipoib does?

- Sean