[...]
> A more problematic (for some definition of problematic) situation is
> when there are many objects of different sizes and if objects whose
> size is identical have vastly differing lifetimes. This introduces
> so-called 'external fragmentation' into the malloc heap
Additional information: The usual 'household number' associated with
that would be that an allocator is considered memory efficient if not
more than 50% of the memory managed by it is effectively lost due to
external fragementation.