Re: pack operation is thrashing my server

There really isn't a global "malloc/mmap at most X bytes".

Sure it can never be 100% accurate because other processes
can also steal memory.

Still a 90+% heuristic can work pretty well. If memory < 512MB then don't
use mmap for example. If memory < 256MB do everything as tight
as possible. gcc is using such heuristics quite successfully.

The only problem might be testing coverage for such options.
It might be useful to add options to force it and then run
the test suite with it.

-Andi