printf("total size is %.0f speedup is %.2f\n",
(double)stats.total_size,
(1.0*stats.total_size)/(stats.total_written+stats.total_read));
printf("total size is %.0f speedup is %.2f\n",
(double)stats.total_size,
(1.0*stats.total_size)/(stats.total_written+stats.total_read));