Hi, Am 05.06.2012 um 15:39 schrieb Mudassar Majeed:
> Let say there are N MPI processes. Each MPI process > has to communicate with some T processes, where T < N. This information is a > directed graph (and every process knows only about its own). I need to > convert it to undirected graph, so that each process will inform T other > processes about it. Every process will update this information. (that may be > stored in an array of maximum size N). What can be the best way to exchange > this information among all MPI processes ? MPI_AllGather and MPI_AllGatherv > do not solve my problem. I'm not sure whether I understand the problem in the correct way: in principle you want to gather all information maybe to the rank 0 process from each process, and then broadcast the complete information to all processes. Why is MPI_AllGather not working for you then? Each element needs to be a vector with the index of the targeted T processes flagged. Each of the T processes have to look then into the received vectors (from all processes) whether they are mentioned there. Each of the T processes can be targeted by more than one of the N processes? -- Reuti
