-> [ 0.000000] [1:@S1] Comm to C1, same weight/penalty (w_a == w_b, ~20) for everybody, each comm should take 1s and finish at the same time
-> [ 0.000000] [3:@S2] Comm to C2, same weight/penalty (w_a == w_b, ~20) for everybody, each comm should take 1s and finish at the same time
+> [ 0.000000] [1:@S1] Send to C1, same weight/penalty (w_a == w_b, ~20) for everybody, each comm should take 1s and finish at the same time
+> [ 0.000000] [3:@S2] Send to C2, same weight/penalty (w_a == w_b, ~20) for everybody, each comm should take 1s and finish at the same time