numa_trivial.c
a4f3918662b9ancarola

numa_trivial.c
View Options

			#include <omp.h>
			#include <stdio.h>
			#include <stdlib.h>
			#include "utility.h"
			#include <stdint.h>

			#define GB (uint64_t)(1 << 30)
			#define SIZE (uint64_t)(8*GB)

			volatile uint8_t *arr;

			#define CACHE_LINE 64

			inline uint64_t next_addr(uint64_t i){
			// Change this part
			return 1;
			}

			inline void init_array(){
			// Change this part
			for(uint64_t i=0; i<SIZE; ++i){
			arr[i] = 1;
			}
			}

			int main(){
			uint64_t i, counter;
			double time;
			volatile uint8_t temp;

			arr = (uint8_t*) malloc(SIZE);
			rand_gen gen = init_rand();

			init_array();

			//Start timer
			set_clock();

			for(i=0, counter=0; i<SIZE; counter++){
			temp = arr[i];
			i += next_addr(i);
			}

			//Stop timer
			time = elapsed_time();

			temp = next_rand(gen)*10;
			i = temp; // Just to suppress the compiler warning for not using temp and gen

			if(counter < 10000000)
			printf("ERROR: Too few accesses. You have to access more elements to measure reasonable time difference.\n");
			if((time/counter) < 1.0e-8)
			printf("ERROR: Time per access is too small. You have to further deoptimize the program to measure reasonable time difference.\n");
			printf("Traversing %lx GB array took total time = %.4g seconds, number of accesses = %lu, %.4g seconds per access\n", SIZE/GB, time, counter, time/counter);

			return 0;
			}