Symbol: system_refcount
kernel/trace/trace_events.c
1230
WARN_ON_ONCE(system_refcount(system) == 0);
kernel/trace/trace_events.c
1246
WARN_ON_ONCE(system_refcount(system) == 0);
kernel/trace/trace_events.c
1261
WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);