system_refcount   649 kernel/trace/trace_events.c 	WARN_ON_ONCE(system_refcount(system) == 0);
system_refcount   665 kernel/trace/trace_events.c 	WARN_ON_ONCE(system_refcount(system) == 0);
system_refcount   680 kernel/trace/trace_events.c 	WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);