On Wed, 14 Jul 1999 12:43:07 +0000 
 Niall Smart <niall@pobox.com> wrote:

 > Perhaps it could be an additional flag to mmap, in this way
 > people wishing to run an overcommited system could do so
 > but those writing programs which must not overcommit for
 > certain memory allocations could ensure they did not do so.

This has already been mentioned.  SVR4 has MAP_NORESERVE specifcally
for this purpose.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>