On Tue, Feb 21, 2012 at 16:42, Jed Brown <[email protected]> wrote:

On Tue, Feb 21, 2012 at 16:37, Barry Smith <[email protected]> wrote:

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Oh, you mean using pthreads to spawn a thread that waits at blocking collective? :-)

The thread should (eventually) be handled by the MPI implementation (because I don't want every library spawning their own thread).

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BTW; do you really think MPI-3 will exist? Or it should exist?

I can call MPIX_Iallreduce() (and lots of other non-blocking collectives) today.

An interface by which libraries could make progress on "user-defined non-blocking collectives" (like matrix assembly, collective semantics, but requiring multiple rounds of communication) is something I would like to see eventually, preferably in MPI. I chatted with Bill and others at the ICERM meeting last month and wrote a paragraph on it for the PUF proposal.