So I would argue that this proposal is not nearly as radical as it might appear
at first. The only real difference is the API, which does of course have some
consequences for implementors. Exactly what those consequences are is something
that we must now determine.
Regarding your specific points, I basically agree with Bill's answers. In our
specific implementation, we would not derive any benefit from making the spawn
operation collective for the parent communicator. Instead, we would most likely
implement the current chapter by performing a spawn on a single process and
then doing a broadcast at the parent's end to set up the intercommunicator. I
would also like to hear from the MPP vendors on this, are there concrete
advantages to making the spawn operation collective?
And, just for the record, I'd like to say that I very much prefer the new
-- Eric Salo Silicon Graphics Inc. "Do you know what the (415)933-2998 2011 N. Shoreline Blvd, 7L-802 last Xon said, just firstname.lastname@example.org Mountain View, CA 94043-1389 before he died?"