I do apologize if this is going to the wrong group so please recommend another group if inappropriate. I do see it as a possible implementation issue. I have a main program that spawns an MPI process A, and a second spawn from main that spawns MPI process B. What I need is to create a communicator between processes A and B. I don't see a way to do this with the current implementation. I do see a way to do this if the local_comm and the peer_comm arguments in the MPI_Intercomm_create() function called in A and B could be the parent_comm in both processes. Since you can't use the same argument for local_comm and peer_comm in the current implementation, I don't see a path forward. Am I missing something here? Is there another way to create a comm between A and B? Thanks Mike _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss