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This commit is contained in:
Fabio Salvini 2016-11-13 10:39:28 +01:00
parent 784416b7ca
commit 51442687a0
3 changed files with 54 additions and 44 deletions
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85
mpi_line/jacobi_mpi_line.c
View File

@ -10,16 +10,22 @@
#define TAG_BORDER 0
void compute_jacobi(int n, double init_value, double threshold, borders b);
double **compute_jacobi(int n, double init_value, double threshold, borders b, int *rows, int *iterations);
int rank;
int numprocs;
int main(int argc, char* argv[]) {
int rank, numprocs;
int n;
double init_value, threshold;
double north, south, east, west;
borders b;
int config_loaded;
configuration config;
double **x;
double startwtime = 0.0, endwtime;
int iterations;
int rows;
MPI_Init(&argc, &argv);
@ -52,35 +58,47 @@ int main(int argc, char* argv[]) {
b.east = east;
b.west = west;
int rows;
if (rank == 0) {
rows = n - (n / numprocs) * (numprocs - 1);
} else {
rows = n / numprocs;
}
LOG(printf("[Process %d/%d] rows: %d\n", rank, numprocs, rows));
double **x;
double max_diff, global_max_diff, new_x;
int i, j, iterations;
MPI_Status status;
double startwtime = 0.0, endwtime;
if (rank == 0) {
startwtime = MPI_Wtime();
}
/* LOG(printf("[Process %d/%d] initializing matrix\n", rank, numprocs)); */
x = compute_jacobi(n, init_value, threshold, b, &rows, &iterations);
if (rank == 0) {
endwtime = MPI_Wtime();
printf("Wall clock time: %fs\n", endwtime - startwtime);
printf("Iterations: %d\n", iterations);
}
destroy_matrix(x, rows);
MPI_Finalize();
return 0;
}
double **compute_jacobi(int n, double init_value, double threshold, borders b, int *rows, int *iterations) {
double **x;
double max_diff, global_max_diff, new_x;
int i, j;
MPI_Status status;
if (rank == 0) {
*rows = n - (n / numprocs) * (numprocs - 1);
} else {
*rows = n / numprocs;
}
LOG(printf("[Process %d/%d] rows: %d\n", rank, numprocs, *rows));
/* LOG(printf("[Process %d/%d] initializing matrix\n", rank, numprocs)); */
/* Initialize the matrix */
x = create_matrix(rows + 2, n + 2);
for (i = 0; i < rows + 2; i++) {
x = create_matrix(*rows + 2, n + 2);
for (i = 0; i < *rows + 2; i++) {
for (j = 1; j <= n; j++) {
x[i][j] = init_value;
}
}
/* Initialize boundary regions */
for (i = 0; i < rows + 2; i++) {
for (i = 0; i < *rows + 2; i++) {
x[i][0] = b.west;
x[i][n + 1] = b.east;
}
@ -91,16 +109,16 @@ int main(int argc, char* argv[]) {
}
if (rank == numprocs - 1){
for (i = 1; i < n + 1; i++) {
x[rows + 1][i] = b.south;
x[*rows + 1][i] = b.south;
}
}
/* LOG(printf("[Process %d/%d] matrix initialized\n", rank, numprocs)); */
/* Iterative refinement of x until values converge */
iterations = 0;
*iterations = 0;
do {
max_diff = 0;
global_max_diff = 0;
for (i = 1; i <= rows; i++) {
for (i = 1; i <= *rows; i++) {
for (j = 1; j <= n; j++) {
new_x = 0.25 * (x[i - 1][j] + x[i][j + 1] + x[i + 1][j] + x[i][j - 1]);
max_diff = (double) fmax(max_diff, fabs(new_x - x[i][j]));
@ -110,8 +128,8 @@ int main(int argc, char* argv[]) {
if (rank % 2 == 0) {
if (rank != numprocs - 1) {
// Send and receive south border
MPI_Send(&x[rows][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[rows + 1][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[*rows][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[*rows + 1][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
}
if (rank != 0) {
// Send and receive north border
@ -124,23 +142,14 @@ int main(int argc, char* argv[]) {
MPI_Send(&x[1][0], n + 2, MPI_DOUBLE, rank - 1, TAG_BORDER, MPI_COMM_WORLD);
if (rank != numprocs - 1) {
// Receive and send south border
MPI_Recv(&x[rows + 1][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[rows][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
MPI_Recv(&x[*rows + 1][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status);
MPI_Send(&x[*rows][0], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD);
}
}
/* LOG(printf("[Process %d/%d] max_diff: %f\n", rank, numprocs, max_diff)); */
MPI_Allreduce(&max_diff, &global_max_diff, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
/* LOG(printf("[Process %d/%d] global_max_diff: %f\n", rank, numprocs, global_max_diff)); */
iterations++;
(*iterations)++;
} while (global_max_diff > threshold);
if (rank == 0) {
endwtime = MPI_Wtime();
printf("Wall clock time: %fs\n", endwtime - startwtime);
printf("Iterations: %d\n", iterations);
}
MPI_Finalize();
return 0;
return x;
}

2
sequential/jacobi.conf
View File

@ -1,7 +1,7 @@
# Configuration file for the Jacobi project.
# The size of the matrix (borders excluded).
N 5000
N 3000
# The value at each border.
NORTH 0.0

11
sequential/jacobi_sequential.c
View File

@ -9,7 +9,7 @@
#include "../config/config.h"
#include "../utils/utils.h"
void compute_jacobi(int n, double init_value, double threshold, borders b);
double **compute_jacobi(int n, double init_value, double threshold, borders b);
int main(int argc, char* argv[]) {
int numprocs;
@ -17,6 +17,7 @@ int main(int argc, char* argv[]) {
configuration config;
borders b;
double startwtime = 0.0, endwtime;
double **x;
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
@ -36,17 +37,18 @@ int main(int argc, char* argv[]) {
b.west = config.west;
startwtime = MPI_Wtime();
compute_jacobi(config.n, config.init_value, config.threshold, b);
x = compute_jacobi(config.n, config.init_value, config.threshold, b);
endwtime = MPI_Wtime();
printf("Wall clock time: %fs\n", endwtime - startwtime);
destroy_matrix(x, config.n + 2);
MPI_Finalize();
return 0;
}
void compute_jacobi(int n, double init_value, double threshold, borders b) {
double **compute_jacobi(int n, double init_value, double threshold, borders b) {
double **x;
double max_diff, new_x;
int i, j;
@ -76,6 +78,5 @@ void compute_jacobi(int n, double init_value, double threshold, borders b) {
}
}
} while (max_diff > threshold);
destroy_matrix(x, n + 2);
return x;
}