我试图使用以下程序以编程方式了解缓存的影响.我正在使用代码获得段错误.我使用了GDB(用-g -O0编译),发现它是分段错误

start = clock() (first occourance)

难道我做错了什么？代码看起来很好.有人可以指出错误吗？

#include dio.h>
#include cpu_time;
    int i = 0;
    int arr[MAX_SIZE];

    /* cpu clock ticks count start */
    start = clock();

    /* Loop 1 */
    for (i = 0; i < MAX_SIZE; i++) 
        arr[i] *= 3;

    /* cpu clock ticks count stop */
    end = clock();

    cpu_time = ((double) (end - start)) / CLOCKS_PER_SEC;

    printf("cpu time for loop 1 %.6f secs.\n",cpu_time);

    /* cpu clock ticks count start */
    start = clock();

    /* Loop 2 */
    for (i = 0; i < MAX_SIZE; i += 16) 
        arr[i] *= 3;

    /* cpu clock ticks count stop */
    end = clock();

    cpu_time = ((double) (end - start)) / CLOCKS_PER_SEC;

    printf("cpu time for loop 2 %.6f secs.\n",cpu_time);

    return 0;
}