[Mpi3-hybridpm] MPI_HELPER_TEAM_CREATE description of INFO

Bronis R. de Supinski bronis at llnl.gov
Thu Feb 17 06:34:36 CST 2011


I think Pavan will be changing to something more along
the lines of "static" and "dynamic", which seemed to
sit better with the other forum members. In that case,
I think the initial description is in terms of what the
implementation does (assign work to the threads statically
or dynamically). I agree that we should also state what
the implications are from the application perspective
(LEAVE is synchronizing across threads so all threads
must call it for any to complete it versus LEAVE has
thread-local completion semantics -- the differences
are significant enough that I think two different
LEAVE functions are appropriate), perhaps in an advice
to users...


On Thu, 17 Feb 2011, Douglas Miller wrote:

> Hi Pavan,
> I'm still looking for a description of the INFO keys "balanced" and "singular" that I like. I guess what seems odd to me about the description in v1.0 is that "balanced" is described in terms of what the implementation does, while "singular" is in terms of what the application does. Wouldn't it be less confusing if both spoke to how the application writer can determine if their code fits a particular model? The way I imagine it, the application writer will have a block of code (in mind or in source files) that does MPI calls and they think it is a candidate for parallelism using a helper team. They would then compare their code to the requirements for "balanced" and "singular" and set them as appropriate.
> I guess we would then have "advice to implementers" that helps guide the implementer on how they should handle the INFO.
> would you agree? I can make an attempt to come up with some text for "balanced" from the application developer's point of view.
> thanks,
> _______________________________________________
> Douglas Miller BlueGene Messaging Development
> IBM Corp., Rochester, MN USA Bldg 030-2 A410
> dougmill at us.ibm.com Douglas Miller/Rochester/IBM

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