Just to follow up, I think that the right thing to do with respect to some sort of transactional model is to have some sort of standard way to request such communications take place probably at init time. We have had such an MPI implementation running in production for several years on a multi-thousand process cluster, and the only thing that needs to be exposed to the users is the ability to turn on/off the functionality all the rest is taken care of just fine within the context of the MPI 2.0 standard, and is 100% standard compliant. Cool! Can you post the API for this thing? Might be a useful thing to start from. Also, its a prototype implementation.
This does not deal with hints on the network state. Yeah, I'm not sure if such hints are valuable enough to be included in the spec. It really falls under the quality-of-service ideas what we've tossed around, so we should write up a proposal for those and see how much QoS people really want.
Greg Bronevetsky Post-Doctoral Researcher 1028 Building 451 Lawrence Livermore National Lab (925) 424-5756 [email protected]