Build Supercomputers with Raspberry Pi 3

Using unrestrained MPI code logic

From here on, you can unleash the full power of your machine by simply commenting out the restraining outer for loop statement, as shown following in the code fragment. Most MPI codes you will write will not necessarily have the for loop coding format, but most of the exercises in this book will use this type of coding structure.

The code fragment will allow unrestrained processing:

// for(total_iter = 1; total_iter < n; total_iter++) ç comment this line { sum = 0.0; // width = 1.0 / (double)total_iter; // width of a segment ç comment this line width = 1.0 / (double)n; // width of a segment ç use this line // for(i = rank + 1; i <= total_iter; i += numprocs) ç comment this line for(i = rank + 1; i <= n; i += numprocs) ...