Index: sys/vm/vm_map.c
===================================================================
--- sys/vm/vm_map.c
+++ sys/vm/vm_map.c
@@ -1644,15 +1644,13 @@
 }
 
 static bool
-vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry)
+vm_map_simplify_neighbor_test(vm_map_entry_t prev, vm_map_entry_t entry)
 {
-	vm_size_t prevsize;
 
-	prevsize = prev->end - prev->start;
 	return (prev->end == entry->start &&
 	    prev->object.vm_object == entry->object.vm_object &&
 	    (prev->object.vm_object == NULL ||
-	    prev->offset + prevsize == entry->offset) &&
+	    prev->offset + prev->end - prev->start == entry->offset) &&
 	    prev->eflags == entry->eflags &&
 	    prev->protection == entry->protection &&
 	    prev->max_protection == entry->max_protection &&
@@ -1662,22 +1660,18 @@
 }
 
 static void
-vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry)
+vm_map_simplify_neighbor_deallocate(vm_map_t map, vm_map_entry_t entry)
 {
 
 	/*
-	 * If the backing object is a vnode object,
-	 * vm_object_deallocate() calls vrele().
-	 * However, vrele() does not lock the vnode
-	 * because the vnode has additional
-	 * references.  Thus, the map lock can be kept
-	 * without causing a lock-order reversal with
-	 * the vnode lock.
+	 * If the backing object is a vnode object, vm_object_deallocate()
+	 * calls vrele().  However, vrele() does not lock the vnode because the
+	 * vnode has additional references.  Thus, the map lock can be kept
+	 * without causing a lock-order reversal with the vnode lock.
 	 *
-	 * Since we count the number of virtual page
-	 * mappings in object->un_pager.vnp.writemappings,
-	 * the writemappings value should not be adjusted
-	 * when the entry is disposed of.
+	 * Since we count the number of virtual page mappings in
+	 * object->un_pager.vnp.writemappings, the writemappings value should
+	 * not be adjusted when the entry is disposed of.
 	 */
 	if (entry->object.vm_object != NULL)
 		vm_object_deallocate(entry->object.vm_object);
@@ -1709,22 +1703,22 @@
 
 	prev = entry->prev;
 	if (prev != &map->header &&
-	    vm_map_mergeable_neighbors(prev, entry)) {
+	    vm_map_simplify_neighbor_test(prev, entry)) {
 		vm_map_entry_unlink(map, prev);
 		entry->start = prev->start;
 		entry->offset = prev->offset;
 		if (entry->prev != &map->header)
 			vm_map_entry_resize_free(map, entry->prev);
-		vm_map_merged_neighbor_dispose(map, prev);
+		vm_map_simplify_neighbor_deallocate(map, prev);
 	}
 
 	next = entry->next;
 	if (next != &map->header &&
-	    vm_map_mergeable_neighbors(entry, next)) {
+	    vm_map_simplify_neighbor_test(entry, next)) {
 		vm_map_entry_unlink(map, next);
 		entry->end = next->end;
 		vm_map_entry_resize_free(map, entry);
-		vm_map_merged_neighbor_dispose(map, next);
+		vm_map_simplify_neighbor_deallocate(map, next);
 	}
 }
 /*