synth_event_add_val
extern int synth_event_add_val(const char *field_name, u64 val,
ret = synth_event_add_val("ts_ns", 1000000, &trace_state);
ret = synth_event_add_val("ts_ms", 1000, &trace_state);
ret = synth_event_add_val("cpu", raw_smp_processor_id(), &trace_state);
ret = synth_event_add_val("next_pid_field", 777, &trace_state);
ret = synth_event_add_val("next_comm_field", (u64)(long)"silly putty",
ret = synth_event_add_val("my_string_field", (u64)(long)"thneed_9",
ret = synth_event_add_val("my_int_field", 3999, &trace_state);
EXPORT_SYMBOL_GPL(synth_event_add_val);