If I understand correctly: If the memory is allocated using malloc() ie. brk() it can't be returned to the system. It will only be placed into a free list. If it is allocated using mmap then it can. Don't know if that actually helps much though. James --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx