Function vm_map_entry_unlink

freebsd/vm/vm_map.c:1480–1520

};

static void
vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry,
    enum unlink_merge_type op)
{
	vm_map_entry_t header, llist, rlist, root;
	vm_size_t max_free_left, max_free_right;

	VM_MAP_ASSERT_LOCKED(map);
	header = &map->header;
	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
	KASSERT(root != NULL,
	    ("vm_map_entry_unlink: unlink object not mapped"));

	vm_map_splay_findprev(root, &llist);
	vm_map_splay_findnext(root, &rlist);
	if (op == UNLINK_MERGE_NEXT) {
		rlist->start = root->start;
		rlist->offset = root->offset;
	}
	if (llist != header) {
		root = llist;
		llist = root->right;
		max_free_left = vm_map_splay_merge_left(header, root, llist);
		max_free_right = vm_map_splay_merge_succ(header, root, rlist);
	} else if (rlist != header) {
		root = rlist;
		rlist = root->left;
		max_free_left = vm_map_splay_merge_pred(header, root, llist);
		max_free_right = vm_map_splay_merge_right(header, root, rlist);
	} else {
		header->left = header->right = header;
		root = NULL;
	}
	if (root != NULL)
		root->max_free = vm_size_max(max_free_left, max_free_right);
	map->root = root;
	VM_MAP_ASSERT_CONSISTENT(map);
	map->nentries--;
	CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
	    map->nentries, entry);
}

/*
 *	vm_map_entry_resize: