Index: sys/sys/pctrie.h
===================================================================
--- sys/sys/pctrie.h
+++ sys/sys/pctrie.h
@@ -473,6 +473,42 @@
 	/* Synchronize to make changes visible. */			\
 	pctrie_node_store(parentp, child, access);			\
 	return (res);							\
+}									\
+									\
+static __inline __unused int						\
+name##_PCTRIE_TRANSFER(struct pctrie_iter *src, struct type *ptr,	\
+    struct pctrie_iter *dst, uint64_t dindex)				\
+{									\
+	struct pctrie_node *d_child, *freed, *node, *s_child;		\
+	smr_pctnode_t *dst_p, *src_p;					\
+	uint64_t *val = name##_PCTRIE_PTR2VAL(ptr);			\
+									\
+	if (val == NULL)						\
+		panic("%s: key not found", __func__);			\
+	dst_p = pctrie_iter_insert_lookup(dst, dindex);			\
+	node = pctrie_node_load(dst_p, NULL, PCTRIE_UNSERIALIZED);	\
+	if (node != PCTRIE_NULL) {					\
+		d_child = allocfn(dst->ptree);				\
+		if (__predict_false(d_child == NULL))			\
+			return (ENOMEM);				\
+	}								\
+	src_p = pctrie_iter_remove(src, &s_child);			\
+	if (s_child != PCTRIE_NULL) {					\
+		freed = pctrie_node_load(src_p, NULL,			\
+		    PCTRIE_UNSERIALIZED);				\
+	} else								\
+		freed = NULL;						\
+	pctrie_node_store(src_p, s_child, PCTRIE_UNSERIALIZED);		\
+	*val = dindex;							\
+	if (node != PCTRIE_NULL)					\
+		pctrie_insert_node(val, dst->node, node, d_child);	\
+	else								\
+		d_child = pctrie_toleaf(val);				\
+	/* Synchronize to make changes visible. */			\
+	pctrie_node_store(dst_p, d_child, access);			\
+	if (freed != NULL)						\
+		freefn(src->ptree, freed);				\
+	return (0);							\
 }
 
 smr_pctnode_t	*pctrie_insert_lookup(struct pctrie *ptree, uint64_t index,
Index: sys/vm/vm_page.c
===================================================================
--- sys/vm/vm_page.c
+++ sys/vm/vm_page.c
@@ -1937,38 +1937,19 @@
 vm_page_iter_rename(struct pctrie_iter *old_pages, vm_page_t m,
     vm_object_t new_object, vm_pindex_t new_pindex)
 {
-	vm_page_t mpred;
-	vm_pindex_t opidx;
+	struct pctrie_iter new_pages;
 
 	KASSERT((m->ref_count & VPRC_OBJREF) != 0,
 	    ("%s: page %p is missing object ref", __func__, m));
 	VM_OBJECT_ASSERT_WLOCKED(m->object);
 	VM_OBJECT_ASSERT_WLOCKED(new_object);
-
-	/*
-	 * Create a custom version of vm_page_insert() which does not depend
-	 * by m_prev and can cheat on the implementation aspects of the
-	 * function.
-	 */
-	opidx = m->pindex;
-	m->pindex = new_pindex;
-	if (vm_radix_insert_lookup_lt(&new_object->rtree, m, &mpred) != 0) {
-		m->pindex = opidx;
+	vm_page_iter_init(&new_pages, new_object);
+	if (vm_radix_transfer(old_pages, m, &new_pages, new_pindex) != 0)
 		return (false);
-	}
 
-	/*
-	 * The operation cannot fail anymore.  The removal must happen before
-	 * the listq iterator is tainted.
-	 */
-	m->pindex = opidx;
-	vm_radix_iter_remove(old_pages);
+	/* The operation cannot fail anymore. */
 	vm_page_remove_radixdone(m);
-
-	/* Return back to the new pindex to complete vm_page_insert(). */
-	m->pindex = new_pindex;
 	m->object = new_object;
-
 	vm_page_insert_radixdone(m, new_object);
 	if (vm_page_any_valid(m))
 		vm_page_dirty(m);
Index: sys/vm/vm_radix.h
===================================================================
--- sys/vm/vm_radix.h
+++ sys/vm/vm_radix.h
@@ -366,5 +366,18 @@
 	return (VM_RADIX_PCTRIE_REPLACE(&rtree->rt_trie, newpage));
 }
 
+/*
+ * Remove the page last visited by the src iterator, change its vm_index to
+ * dindex, and insert it near the dst iterator.  Panic if the src page has been
+ * removed or if the dst trie already has a dindex page.  Return zero on success
+ * or a non-zero error on memory allocation failure.
+ */
+static __inline int
+vm_radix_transfer(struct pctrie_iter *src, vm_page_t m,
+    struct pctrie_iter *dst, vm_pindex_t dindex)
+{
+	return (VM_RADIX_PCTRIE_TRANSFER(src, m, dst, dindex));
+}
+
 #endif /* _KERNEL */
 #endif /* !_VM_RADIX_H_ */