temporary trace:

lib/dns/probes.d

@@ -27,4 +27,7 @@ provider libdns {
 	probe xfrin_recv_try_axfr(void *, char *, int);
 	probe xfrin_sent(void *, char *, int);
 	probe xfrin_start(void *, char *);
+
+	probe qpcache_addrdataset_done(void *, void *);
+	probe qpcache_addrdataset_start(void *, void *);
 };

lib/dns/qpcache.c

@@ -61,6 +61,7 @@
 #include <dns/zonekey.h>
 
 #include "db_p.h"
+#include "probes.h"
 #include "qpcache_p.h"
 
 #define CHECK(op)                            \
@@ -3298,6 +3299,8 @@ addrdataset(dns_db_t *db, dns_dbnode_t *node,
 		return (result);
 	}
 
+	LIBDNS_QPCACHE_ADDRDATASET_START(db, node);
+
 	name = dns_fixedname_initname(&fixed);
 	dns_name_copy(&qpnode->name, name);
 	dns_rdataset_getownercase(rdataset, name);
@@ -3453,6 +3456,8 @@ addrdataset(dns_db_t *db, dns_dbnode_t *node,
 		isc_loop_rcu_barrier(isc_loop());
 	}
 
+	LIBDNS_QPCACHE_ADDRDATASET_DONE(db, node);
+
 	return (result);
 }