[ofw][patch][ND provider] Improving latency of ms-mpi

[Sean Hefty]

>Our suggestion is this: add a new environment variable. If that variable
>doesn't exist the parameter is out only.
>If it is set, the parameter is in/out. This will promise that older
>applications still work as well. People who write according to the new
>api will set this environment variable. Fab, can you make sure that the
>new nd version will allow this parameter to be in/out?
>
>Controlling inline or not will still be done using an environment
>variable (as Leonid sent).
>
>Does this makes sense?

Changing the API is the wrong way to go.  This is the major drawback of adhering
to an external controlled API.

Rather than using an environment variable to indicate that you'll pass in the
value some other way, just let the variable specify what the default inline data
value should be.

- Sean