Hi, My objective is I want to calculate the time perform by MPI_Send & MPI_Recv . In case MPI_Send, i can put the timer before the MPI_Send and after its. like this " t1=MPI_Wtime(), MPI_Send.... t2= MPI_Wtime tsend= t2 -t1; it mean when the message go to the system buffer, the control return to the sending process. So I can measure the MPI_Send. But my problem in MPI_Recv. If i do like MPI_Send( put the timer before and after MPI_Recv) I think it wrong. Because we dont know exactly when the message reach the system buffer in receiving side. So how can we measure the MPI_Recv operation time( time when the message is copied from the system buffer to the receive buffer) ?
Thanks