From 14541623a473ae3f2e4b910bbb2d219b504b17ba Mon Sep 17 00:00:00 2001 From: Fabio Salvini Date: Sun, 13 Nov 2016 13:11:24 +0100 Subject: [PATCH] mpi line with matrix exchange --- mpi_line/jacobi_mpi_line.c | 61 +++++++++++++++++++++++++++----------- utils/utils.c | 22 +++++++------- utils/utils.h | 18 ++++++++++- 3 files changed, 73 insertions(+), 28 deletions(-) diff --git a/mpi_line/jacobi_mpi_line.c b/mpi_line/jacobi_mpi_line.c index 5f07080..2a99683 100644 --- a/mpi_line/jacobi_mpi_line.c +++ b/mpi_line/jacobi_mpi_line.c @@ -3,14 +3,16 @@ */ #include +#include #include #include #include "../config/config.h" #include "../utils/utils.h" #define TAG_BORDER 0 +#define TAG_MATRIX 1 -double *compute_jacobi(int n, double init_value, double threshold, borders b, int *rows, int *iterations); +double *compute_jacobi(int n, double init_value, double threshold, borders b, int *iterations); int rank; int numprocs; @@ -25,7 +27,6 @@ int main(int argc, char* argv[]) { double *x; double startwtime = 0.0, endwtime; int iterations; - int rows; MPI_Init(&argc, &argv); @@ -62,12 +63,13 @@ int main(int argc, char* argv[]) { startwtime = MPI_Wtime(); } - x = compute_jacobi(n, init_value, threshold, b, &rows, &iterations); + x = compute_jacobi(n, init_value, threshold, b, &iterations); if (rank == 0) { endwtime = MPI_Wtime(); printf("Wall clock time: %fs\n", endwtime - startwtime); printf("Iterations: %d\n", iterations); + /* print_sa_matrix(x, n + 2, n + 2); */ } destroy_sa_matrix(x); @@ -77,28 +79,31 @@ int main(int argc, char* argv[]) { return 0; } -double *compute_jacobi(int n, double init_value, double threshold, borders b, int *rows, int *iterations) { +double *compute_jacobi(int n, double init_value, double threshold, borders b, int *iterations) { + double *complete_x; double *x; double max_diff, global_max_diff, new_x; int i, j; + int rows, rows_to_transmit; + int receive_pos; MPI_Status status; if (rank == 0) { - *rows = n - (n / numprocs) * (numprocs - 1); + rows = n - (n / numprocs) * (numprocs - 1); } else { - *rows = n / numprocs; + rows = n / numprocs; } - LOG(printf("[Process %d/%d] rows: %d\n", rank, numprocs, *rows)); + 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_sa_matrix(*rows + 2, n + 2); - for (i = 0; i < *rows + 2; i++) { + x = create_sa_matrix(rows + 2, n + 2); + for (i = 0; i < rows + 2; i++) { for (j = 1; j <= n; j++) { x[sa_index(n + 2, i, j)] = init_value; } } /* Initialize boundary regions */ - for (i = 0; i < *rows + 2; i++) { + for (i = 0; i < rows + 2; i++) { x[sa_index(n + 2, i, 0)] = b.west; x[sa_index(n + 2, i, n + 1)] = b.east; } @@ -109,7 +114,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in } if (rank == numprocs - 1){ for (i = 1; i < n + 1; i++) { - x[sa_index(n + 2, *rows + 1, i)] = b.south; + x[sa_index(n + 2, rows + 1, i)] = b.south; } } /* LOG(printf("[Process %d/%d] matrix initialized\n", rank, numprocs)); */ @@ -118,7 +123,7 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in 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[sa_index(n + 2, i - 1, j)] + x[sa_index(n + 2, i, j + 1)] + x[sa_index(n + 2, i + 1, j)] + x[sa_index(n + 2, i, j - 1)]); max_diff = (double) fmax(max_diff, fabs(new_x - x[sa_index(n + 2, i, j)])); @@ -128,8 +133,8 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in if (rank % 2 == 0) { if (rank != numprocs - 1) { // Send and receive south border - MPI_Send(&x[sa_index(n + 2, *rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); - MPI_Recv(&x[sa_index(n + 2, *rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); + MPI_Send(&x[sa_index(n + 2, rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); + MPI_Recv(&x[sa_index(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); } if (rank != 0) { // Send and receive north border @@ -142,8 +147,8 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in MPI_Send(&x[sa_index(n + 2, 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[sa_index(n + 2, *rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); - MPI_Send(&x[sa_index(n + 2, *rows, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD); + MPI_Recv(&x[sa_index(n + 2, rows + 1, 0)], n + 2, MPI_DOUBLE, rank + 1, TAG_BORDER, MPI_COMM_WORLD, &status); + MPI_Send(&x[sa_index(n + 2, 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)); */ @@ -151,5 +156,27 @@ double *compute_jacobi(int n, double init_value, double threshold, borders b, in /* LOG(printf("[Process %d/%d] global_max_diff: %f\n", rank, numprocs, global_max_diff)); */ (*iterations)++; } while (global_max_diff > threshold); - return x; + + if (rank == 0) { + complete_x = create_sa_matrix(n + 2, n + 2); + memcpy(complete_x, x, (rows + 1) * (n + 2) * sizeof(double)); /* rows + 2 if rank == numprocs - 1 */ + rows_to_transmit = n / numprocs; + receive_pos = rows + 1; + for (i = 1; i < numprocs; i++) { + if (i == numprocs - 1) { + rows_to_transmit++; + } + MPI_Recv(&complete_x[sa_index(n + 2, receive_pos, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, i, TAG_MATRIX, MPI_COMM_WORLD, &status); + receive_pos += n / numprocs; + } + } else { + complete_x = NULL; + rows_to_transmit = rows; + if (rank == numprocs - 1) { + rows_to_transmit++; + } + MPI_Send(&x[sa_index(n + 2, 1, 0)], rows_to_transmit * (n + 2), MPI_DOUBLE, 0, TAG_MATRIX, MPI_COMM_WORLD); + } + + return complete_x; } diff --git a/utils/utils.c b/utils/utils.c index ee8f553..bf533c0 100644 --- a/utils/utils.c +++ b/utils/utils.c @@ -1,9 +1,6 @@ #include #include -/* - * Create a matrix stored in a single array. - */ double *create_sa_matrix(int rows, int cols) { double *x; @@ -11,21 +8,26 @@ double *create_sa_matrix(int rows, int cols) { return x; } -/* - * Destroy a single array matrix. - */ void destroy_sa_matrix(double *x) { free(x); } -/* - * Get the index for the single array matrix - * that correspond to the given row and column. - */ int sa_index(int cols, int r, int c) { return r * cols + c; } + +void print_sa_matrix(double *x, int rows, int cols) { + int i, j; + for (i = 0; i < rows; i++) { + for (j = 0; j < cols; j++) { + printf("%f\t", x[sa_index(cols, i, j)]); + } + printf("\n"); + } + fflush(stdout); +} + double **create_matrix(int rows, int cols) { int i; double **x; diff --git a/utils/utils.h b/utils/utils.h index 201cc60..29c343f 100644 --- a/utils/utils.h +++ b/utils/utils.h @@ -17,11 +17,27 @@ typedef struct borders { } borders; +/* + * Create a matrix stored in a single array. + */ double *create_sa_matrix(int rows, int cols); + +/* + * Destroy a single array matrix. + */ void destroy_sa_matrix(double *x); + +/* + * Get the index for the single array matrix + * that correspond to the given row and column. + */ int sa_index(int cols, int r, int c); +/* + * Print a single array matrix. + */ +void print_sa_matrix(double *x, int rows, int cols); + double **create_matrix(int rows, int cols); void destroy_matrix(double **x, int rows); - void print_matrix(double **x, int rows, int cols);