find_target_event_var 3920 kernel/trace/trace_events_hist.c 	var_field = find_target_event_var(hist_data, NULL, NULL, track_data_var_str);
find_target_event_var 4206 kernel/trace/trace_events_hist.c 	hist_field = find_target_event_var(hist_data, system, event, var);