...
starttime = MPI_Wtime();
...
...
endtime = MPI_Wtime();
mytime = endtime-starttime;
printf("%d: mysum = %g, time = %g\n",myid,mysum,mytime);
MPI_Reduce(&mytime, &maxtime, 1, MPI_DOUBLE,MPI_MAX, 0, MPI_COMM_WORLD);
MPI_Reduce(&mytime, &mintime, 1, MPI_DOUBLE, MPI_MIN, 0,MPI_COMM_WORLD);
MPI_Reduce(&mytime, &avgtime, 1, MPI_DOUBLE, MPI_SUM, 0,MPI_COMM_WORLD);
if (myid == 0) {
avgtime /= numprocs;
printf("Min: %lf Max: %lf Avg: %lf\n", mintime, maxtime,avgtime);
}