Tested by Peter, with the following debugging change:
```
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index a678635..5070e67 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -481,6 +481,9 @@ static const char w_stillcold[] = "Witness is still cold\n";
static struct witness_order_list_entry order_lists[] = {
+ { "ufs", &lock_class_lockmgr },
+ { "allproc", &lock_class_sx },
+ { NULL, NULL },
/*
* sx locks
*/
```