Material analisis del rendimiento

src/omp/false-sharing/cache-miss-col-parallel.c

@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <omp.h>
+#include <stdlib.h>
+
+#define NUM  10000
+
+float   array[NUM][NUM];
+
+int main( int argc, char *argv[ ] ){
+  float sum = 0.;
+
+  if (argc < 2) {
+    printf("Se espera el número de hilos\n");
+    return -1;
+  }
+
+  omp_set_num_threads(atoi(argv[1]));
+  double start = omp_get_wtime();
+
+#pragma omp parallel for shared(array) reduction(+:sum)
+  for( int i = 0; i < NUM; i++ ){
+    for( int j = 0; j < NUM; j++ ){
+      sum += array[ j ][ i ]; // acceso por columnas (j, i)
+    }
+  }
+  double finish = omp_get_wtime();
+  double elapsed = finish - start;
+
+  printf("Tiempo = %2.8f seconds\n", elapsed);
+} 

src/omp/false-sharing/cache-miss-col.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <omp.h>
+
+#define NUM  10000
+
+float   array[NUM][NUM];
+
+int main( int argc, char *argv[ ] ){
+  float sum = 0.;
+
+  double start = omp_get_wtime();
+
+  for( int i = 0; i < NUM; i++ ){
+    for( int j = 0; j < NUM; j++ ){
+      sum += array[ j ][ i ]; // acceso por columnas (j, i)
+    }
+  }
+  double finish = omp_get_wtime();
+  double elapsed = finish - start;
+
+  printf("Tiempo = %2.8f seconds\n", elapsed);
+} 

src/omp/false-sharing/cache-miss-row-parallel.c

@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <omp.h>
+#include <stdlib.h>
+
+#define NUM  10000
+
+float array[NUM][NUM];
+
+int main( int argc, char *argv[ ] ){
+  float sum = 0.;
+
+  if (argc < 2) {
+    printf("Se espera el número de hilos\n");
+    return -1;
+  }
+
+  omp_set_num_threads(atoi(argv[1]));
+
+  double start = omp_get_wtime();
+
+#pragma omp parallel for shared(array) reduction(+:sum) schedule(dynamic)
+  for( int i = 0; i < NUM; i++ ){
+    for( int j = 0; j < NUM; j++ ){
+      sum += array[ i ][ j ]; // acceso por filas
+    }
+  }
+  double finish = omp_get_wtime();
+  double elapsed = finish - start;
+
+  printf("Tiempo = %2.8f seconds\n", elapsed);
+} 

src/omp/false-sharing/cache-miss-row.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <omp.h>
+
+#define NUM  10000
+
+float array[NUM][NUM];
+
+int main( int argc, char *argv[ ] ){
+  float sum = 0.;
+
+  double start = omp_get_wtime();
+
+  for( int i = 0; i < NUM; i++ ){
+    for( int j = 0; j < NUM; j++ ){
+      sum += array[ i ][ j ]; // acceso por filas
+    }
+  }
+  double finish = omp_get_wtime();
+  double elapsed = finish - start;
+
+  printf("Tiempo = %2.8f seconds\n", elapsed);
+}