extern void sum_thread_stats(struct thread_stat *dst, struct thread_stat *src, int nr);
extern void sum_group_stats(struct group_run_stats *dst, struct group_run_stats *src);
extern void init_thread_stat(struct thread_stat *ts);
extern void init_group_run_stat(struct group_run_stats *gs);
extern void eta_to_str(char *str, unsigned long eta_sec);
extern int calc_lat(struct io_stat *is, unsigned long *min, unsigned long *max, double *mean, double *dev);
extern void sum_thread_stats(struct thread_stat *dst, struct thread_stat *src, int nr);
extern void sum_group_stats(struct group_run_stats *dst, struct group_run_stats *src);
extern void init_thread_stat(struct thread_stat *ts);
extern void init_group_run_stat(struct group_run_stats *gs);
extern void eta_to_str(char *str, unsigned long eta_sec);
extern int calc_lat(struct io_stat *is, unsigned long *min, unsigned long *max, double *mean, double *dev);