On Mon, Feb 04, 2008 at 02:54:46PM -0500, Richard Treumann wrote: > In my example, each sender task 1 to n-1 will have one rendezvous message > to task 0 at a time. The MPI standard suggests descriptors be small enough > and there be enough descriptor space for reasonable programs . The > standard is clear that unreasonable programs can run out of space and fail. > The standard does not try to quantify reasonableness. You are right about your example, but I was not talking specifically about it. Your example should work with Open MPI over IB/TCP because while rank 0 sleeps without calling progress, transport layer flow control should throttle senders. (SM doesn't have flow control that is why it fails.) What I was trying to say that in MPI a process can't fully control its resource usage.
-- Gleb.