P0 P1 commA 0 1 2 3 4 5 6 7 8 P2 P3 commB 0 1 2 6 5 4 3 commA_mpi P0 P1 leader rank in local = 0 remote rank in peer = 3 0 1 commB_mpi P2 P3 leader rank in local = 1 remote rank in peer = 0 0 1 step 1 step 2 commA_mpi P0 P1 0 1 commB_mpi P2 P3 0 1 step 3 P0 P1 0 1 2 3 4 5 6 7 8 P2 P3 0 1 2 6 5 4 3 inter_comm_mpi inter_comm false true 50 1.0 cm false 10 0 true true true 2.0.8 1867 1176 53 24 0.8489555436529191 true true true 138