The memory in 64-bit LispWorks is arranged in segments, which belong to generations. Unlike 32-bit LispWorks, segments are sparsely allocated in memory, that is they not contiguous.
Each segment has an allocation type, which defines the type of objects that the segment contains. The system creates and destroys segments as needed. A generation may or may not contain a segment for a specific allocation type, and a generation may contain more than one segment for any particular allocation type. Segments may change in size.
You can see the allocation for each allocation type in the output of:
(room t)
Additionally you can see the segments of each generation in the output of:
(room :full)
After the total allocation in each generation, this prints the allocation type for each segment followed by the hexadecimal address range for allocating objects.