---------------------+
   | DLA descriptors            |
   +----------------------------+
   | first virtual DLA segment  |
   +----------------------------+
   | second virtual DLA segment |
   |                            |
   |                            |
   +----------------------------+
              ...
   +----------------------------+
   | last virtual DLA segment   |
   |                            |
   +----------------------------+
</PRE>
   The diagram above does not show the physical order of