> >> a better allocator won't have the same effect, it will just be
> >> different.  the allocator is the same whether you merge or don't
> >> merge.  the only difference is the overhead of allocating when you
> >> need less map entries (there are less map entries to scan, and less
> >> memory consumed by them).  in the end, the map entries will still mean
> >> the same thing.
> >
> >i don't see any reason to use the same vm_map_entry structure for
> >chunked blocks.
> 
> even if you used different structures for chunked blocks, you'd still
> have the memory allocated underneath them.

you can use a bitmap (one bit per page) and
i think it's acceptable.

YAMAMOTO Takashi