Index: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
===================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
@@ -1420,6 +1420,9 @@
 	 */
 	if (offset == db->db.db_offset && blksz == db->db.db_size &&
 	    DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA) {
+#ifdef _KERNEL
+		curthread->td_ru.ru_oublock++;
+#endif
 		dbuf_assign_arcbuf(db, buf, tx);
 		dbuf_rele(db, FTAG);
 	} else {