Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- /**********************************************************************************************
- * Matrix Multiplication Program using MPI.
- *
- * Viraj Brian Wijesuriya - University of Colombo School of Computing, Sri Lanka.
- *
- * Works with any type of two matrixes [A], [B] which could be multiplied to produce a matrix [c].
- *
- * Master process initializes the multiplication operands, distributes the muliplication
- * operation to worker processes and reduces the worker results to construct the final output.
- *
- ************************************************************************************************/
- #include<stdio.h>
- #include<mpi.h>
- #define NUM_ROWS_A 12 //rows of input [A]
- #define NUM_COLUMNS_A 12 //columns of input [A]
- #define NUM_ROWS_B 12 //rows of input [B]
- #define NUM_COLUMNS_B 12 //columns of input [B]
- #define MASTER_TO_SLAVE_TAG 1 //tag for messages sent from master to slaves
- #define SLAVE_TO_MASTER_TAG 4 //tag for messages sent from slaves to master
- void makeAB(); //makes the [A] and [B] matrixes
- void printArray(); //print the content of output matrix [C];
- int rank; //process rank
- int size; //number of processes
- int i, j, k; //helper variables
- double mat_a[NUM_ROWS_A][NUM_COLUMNS_A]; //declare input [A]
- double mat_b[NUM_ROWS_B][NUM_COLUMNS_B]; //declare input [B]
- double mat_result[NUM_ROWS_A][NUM_COLUMNS_B]; //declare output [C]
- double start_time; //hold start time
- double end_time; // hold end time
- int low_bound; //low bound of the number of rows of [A] allocated to a slave
- int upper_bound; //upper bound of the number of rows of [A] allocated to a slave
- int portion; //portion of the number of rows of [A] allocated to a slave
- MPI_Status status; // store status of a MPI_Recv
- MPI_Request request; //capture request of a MPI_Isend
- int main(int argc, char *argv[])
- {
- MPI_Init(&argc, &argv); //initialize MPI operations
- MPI_Comm_rank(MPI_COMM_WORLD, &rank); //get the rank
- MPI_Comm_size(MPI_COMM_WORLD, &size); //get number of processes
- /* master initializes work*/
- if (rank == 0) {
- makeAB();
- start_time = MPI_Wtime();
- for (i = 1; i < size; i++) {//for each slave other than the master
- portion = (NUM_ROWS_A / (size - 1)); // calculate portion without master
- low_bound = (i - 1) * portion;
- if (((i + 1) == size) && ((NUM_ROWS_A % (size - 1)) != 0)) {//if rows of [A] cannot be equally divided among slaves
- upper_bound = NUM_ROWS_A; //last slave gets all the remaining rows
- } else {
- upper_bound = low_bound + portion; //rows of [A] are equally divisable among slaves
- }
- //send the low bound first without blocking, to the intended slave
- MPI_Isend(&low_bound, 1, MPI_INT, i, MASTER_TO_SLAVE_TAG, MPI_COMM_WORLD, &request);
- //next send the upper bound without blocking, to the intended slave
- MPI_Isend(&upper_bound, 1, MPI_INT, i, MASTER_TO_SLAVE_TAG + 1, MPI_COMM_WORLD, &request);
- //finally send the allocated row portion of [A] without blocking, to the intended slave
- MPI_Isend(&mat_a[low_bound][0], (upper_bound - low_bound) * NUM_COLUMNS_A, MPI_DOUBLE, i, MASTER_TO_SLAVE_TAG + 2, MPI_COMM_WORLD, &request);
- }
- }
- //broadcast [B] to all the slaves
- MPI_Bcast(&mat_b, NUM_ROWS_B*NUM_COLUMNS_B, MPI_DOUBLE, 0, MPI_COMM_WORLD);
- /* work done by slaves*/
- if (rank > 0) {
- //receive low bound from the master
- MPI_Recv(&low_bound, 1, MPI_INT, 0, MASTER_TO_SLAVE_TAG, MPI_COMM_WORLD, &status);
- //next receive upper bound from the master
- MPI_Recv(&upper_bound, 1, MPI_INT, 0, MASTER_TO_SLAVE_TAG + 1, MPI_COMM_WORLD, &status);
- //finally receive row portion of [A] to be processed from the master
- MPI_Recv(&mat_a[low_bound][0], (upper_bound - low_bound) * NUM_COLUMNS_A, MPI_DOUBLE, 0, MASTER_TO_SLAVE_TAG + 2, MPI_COMM_WORLD, &status);
- for (i = low_bound; i < upper_bound; i++) {//iterate through a given set of rows of [A]
- for (j = 0; j < NUM_COLUMNS_B; j++) {//iterate through columns of [B]
- for (k = 0; k < NUM_ROWS_B; k++) {//iterate through rows of [B]
- mat_result[i][j] += (mat_a[i][k] * mat_b[k][j]);
- }
- }
- }
- //send back the low bound first without blocking, to the master
- MPI_Isend(&low_bound, 1, MPI_INT, 0, SLAVE_TO_MASTER_TAG, MPI_COMM_WORLD, &request);
- //send the upper bound next without blocking, to the master
- MPI_Isend(&upper_bound, 1, MPI_INT, 0, SLAVE_TO_MASTER_TAG + 1, MPI_COMM_WORLD, &request);
- //finally send the processed portion of data without blocking, to the master
- MPI_Isend(&mat_result[low_bound][0], (upper_bound - low_bound) * NUM_COLUMNS_B, MPI_DOUBLE, 0, SLAVE_TO_MASTER_TAG + 2, MPI_COMM_WORLD, &request);
- }
- /* master gathers processed work*/
- if (rank == 0) {
- for (i = 1; i < size; i++) {// untill all slaves have handed back the processed data
- //receive low bound from a slave
- MPI_Recv(&low_bound, 1, MPI_INT, i, SLAVE_TO_MASTER_TAG, MPI_COMM_WORLD, &status);
- //receive upper bound from a slave
- MPI_Recv(&upper_bound, 1, MPI_INT, i, SLAVE_TO_MASTER_TAG + 1, MPI_COMM_WORLD, &status);
- //receive processed data from a slave
- MPI_Recv(&mat_result[low_bound][0], (upper_bound - low_bound) * NUM_COLUMNS_B, MPI_DOUBLE, i, SLAVE_TO_MASTER_TAG + 2, MPI_COMM_WORLD, &status);
- }
- end_time = MPI_Wtime();
- printf("\nRunning Time = %f\n\n", end_time - start_time);
- printArray();
- }
- MPI_Finalize(); //finalize MPI operations
- return 0;
- }
- void makeAB()
- {
- for (i = 0; i < NUM_ROWS_A; i++) {
- for (j = 0; j < NUM_COLUMNS_A; j++) {
- mat_a[i][j] = i + j;
- }
- }
- for (i = 0; i < NUM_ROWS_B; i++) {
- for (j = 0; j < NUM_COLUMNS_B; j++) {
- mat_b[i][j] = i*j;
- }
- }
- }
- void printArray()
- {
- for (i = 0; i < NUM_ROWS_A; i++) {
- printf("\n");
- for (j = 0; j < NUM_COLUMNS_A; j++)
- printf("%8.2f ", mat_a[i][j]);
- }
- printf("\n\n\n");
- for (i = 0; i < NUM_ROWS_B; i++) {
- printf("\n");
- for (j = 0; j < NUM_COLUMNS_B; j++)
- printf("%8.2f ", mat_b[i][j]);
- }
- printf("\n\n\n");
- for (i = 0; i < NUM_ROWS_A; i++) {
- printf("\n");
- for (j = 0; j < NUM_COLUMNS_B; j++)
- printf("%8.2f ", mat_result[i][j]);
- }
- printf("\n\n");
- }
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement