trace_event_add_trigger
retval = trace_event_add_trigger(params->common.events, optarg);
retval = trace_event_add_trigger(params->common.events, optarg);
retval = trace_event_add_trigger(params->common.events, optarg);
retval = trace_event_add_trigger(params->common.events, optarg);
int trace_event_add_trigger(struct trace_events *event, char *trigger);