--- xnu/xnu-12377.101.15/libkern/c++/priority_queue.cpp
+++ xnu/xnu-7195.101.1/libkern/c++/priority_queue.cpp
@@ -29,7 +29,6 @@
 #if KERNEL
 #include <kern/priority_queue.h>
 #include <mach/vm_param.h>
-#include <vm/vm_memtag.h>
 
 #ifdef __LP64__
 static_assert(PRIORITY_QUEUE_ENTRY_CHILD_BITS >= VM_KERNEL_POINTER_SIGNIFICANT_BITS,
@@ -129,18 +128,12 @@
 	static inline void
 	pack_child(entry_t e, const entry_t child)
 	{
-#if CONFIG_KERNEL_TAGGING
-		e->tag = vm_memtag_extract_tag((vm_offset_t)child);
-#endif /* CONFIG_KERNEL_TAGGING */
 		e->child = (long)child;
 	}
 
 	static inline entry_t
 	unpack_child(entry_t e)
 	{
-#if CONFIG_KERNEL_TAGGING
-		return (entry_t)(vm_memtag_insert_tag(e->child, e->tag));
-#endif /* CONFIG_KERNEL_TAGGING */
 		return (entry_t)e->child;
 	}
 
@@ -234,12 +227,6 @@
 	}
 
 	static inline void
-	list_clear(entry_t e)
-	{
-		e->next = e->prev = NULL;
-	}
-
-	static inline void
 	list_remove(entry_t elt)
 	{
 		assert(elt->prev != NULL);
@@ -255,31 +242,13 @@
 		if (elt->next != NULL) {
 			elt->next->prev = elt->prev;
 		}
-		list_clear(elt);
 	}
 
 	static inline bool
 	sift_down(queue_t que, entry_t elt)
 	{
-		bool was_root = (que->pq_root == elt);
-
-		if (!was_root) {
-			remove_non_root(que, elt);
-			insert(que, elt, false);
-		} else if (unpack_child(elt)) {
-			remove_root(que, elt);
-			insert(que, elt, false);
-		} else {
-			/*
-			 * If the queue is reduced to a single element,
-			 * we have nothing to do.
-			 *
-			 * It is important not to, so that pq_root remains
-			 * non null at all times during priority changes,
-			 * so that unsynchronized peeking at the "emptiness"
-			 * of the priority queue works as expected.
-			 */
-		}
+		bool was_root = remove(que, elt);
+		insert(que, elt);
 		return was_root;
 	}
 
@@ -293,7 +262,7 @@
 		/* Remove the element from its current level list */
 		list_remove(elt);
 		/* Re-insert the element into the heap with a merge */
-		return insert(que, elt, false);
+		return insert(que, elt);
 	}
 
 	static inline entry_t
@@ -313,7 +282,6 @@
 			child = meld_pair(que, child);
 			new_root = merge_pair(que, que->pq_root, child);
 			que->pq_root = new_root;
-			pack_child(elt, nullptr);
 		}
 
 		return elt;
@@ -352,12 +320,8 @@
 	}
 
 	static inline bool
-	insert(queue_t que, entry_t elt, bool clear = true)
-	{
-		if (clear) {
-			list_clear(elt);
-			pack_child(elt, nullptr);
-		}
+	insert(queue_t que, entry_t elt)
+	{
 		return (que->pq_root = merge_pair(que, que->pq_root, elt)) == elt;
 	}
 
@@ -365,13 +329,7 @@
 	remove_root(queue_t que, entry_t old_root)
 	{
 		entry_t new_root = unpack_child(old_root);
-
-		if (new_root) {
-			que->pq_root = meld_pair(que, new_root);
-			pack_child(old_root, nullptr);
-		} else {
-			que->pq_root = NULL;
-		}
+		que->pq_root = new_root ? meld_pair(que, new_root) : NULL;
 		return old_root;
 	}
 
@@ -380,9 +338,13 @@
 	{
 		if (elt == que->pq_root) {
 			remove_root(que, elt);
+			elt->next = elt->prev = NULL;
+			elt->child = 0;
 			return true;
 		} else {
 			remove_non_root(que, elt);
+			elt->next = elt->prev = NULL;
+			elt->child = 0;
 			return false;
 		}
 	}