MAX_PRIO_STR_LEN
printf(" %-*s", MAX_PRIO_STR_LEN, "prio");
printf(" %-*s", MAX_PRIO_STR_LEN, "");
printf(" %.*s", MAX_PRIO_STR_LEN, graph_dotted_line);
printf(" %-*s ", MAX_PRIO_STR_LEN, timehist_get_priostr(evsel, thread, sample));