[ofw] [RFC] Locally generated path records

[Hal Rosenstock]

On Mon, Jul 21, 2008 at 4:56 PM, Sean Hefty <sean.hefty at intel.com> wrote:
>>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.

OK; I missed the distinction between on and off subnet previously.

>>>  (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.

For the reversible path case.

-- Hal

>
> - Sean
>
>