Ping pong exercise from MPI day2
Additional comments:
- Ping-pong is to be executed between 2 processes.
- Place a ping-pong counter to count the back and forth. Each ping-pong shot(aka messge transfer) will add 1 to the counter.
- MPI_Send and MPI_Recv performs blocking operations. This means that the code after these statements won't execute until the operations are completed and a receipt is sent back.
- Use MPI_Wtime() to get the times and then subtract them.