mlock() issues

[Sad Clouds <cryintothebluesky%googlemail.com@localhost>]

Hi, I've been trying to figure out why it's not possible to lock more
than 666MB of memory, and I'm beginning to think it might be a kernel
issue.

This is what I'm doing:

Run program as root.
Lock only memory segments that are multiples of system page size.
ulimit -l is set to unlimited.
proc.curproc.rlimit.memorylocked.soft = 697976149
proc.curproc.rlimit.memorylocked.hard = 2093928448

With all of the above set, for some reason it's not possible to lock
more than 666MB.

Can anyone shed some light on this?