questions about apc-configuration

hey folks, forgive me if any of my questions are obvious and don't hesitate to point me to some documents describing that behaviour or configuration. I've reinstalled apc 3.0.11 after having some problems with the older versions with my php-4.4.x install (don't question why I'm running still php4, its because of old software which needs some time to get rewritten). I've read that in 3.0.11 mmap became the default, hence I compiled apc with mmap support. now, how do I configure how much space is used in mmap or how do I tell it to actually use mmap? Also it seems that my cache is running full with 1 SHM segment of 30M even if I configured it to use 2 SHM segments of that size. Here is some output from the apc.php-script: --- Shared Memory 1 Segment(s) with 30.0 MBytes Cache full count 5376 ... apc.shm_segments 2 apc.shm_size 30 --- any ideas why only one segment is used then? This is on gentoo-linux and using the ebuild-script for that. on another machine I have nearly the opposite problem. apc is configured to use one shm-segment, uses only one shm-segment but allocates two segments (seen by ipcs and the process-size of php). Any ideas how to track this down too? Thanks in advance, Thomas Seifert