Where is the default max locked memory value coming from? - apc

Question

So on one system, I have values that are pretty wide open:
$ ulimit -a | grep mem
max locked memory (kbytes, -l) 40000
max memory size (kbytes, -m) unlimited
virtual memory (kbytes, -v) unlimited
Another system has much more limiting values, but I can't for the life of me find out where the 32MB upper limit (it is 32MB despite the mislabling) is being set:
# ulimit -a | grep mem
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
virtual memory (kbytes, -v) unlimited
The second system is a RHEL 5.5 box. I am looking to increase this limit for at least one user- I need a bigger APC mmap memory allocation, but I can't go above 30 MB without running into the above limit, and I would rather not hack the provided apache init script. Where should I be trying to override the system default value so I can map a bigger segment of memory? Doing it in limits.conf for the apache user doesn't do a whole lot; probably because the init script doesn't do anything through PAM.

Answer 1

If the user granularity setting you tried isn't working, you should make sure that's you've correctly matched which user is hitting the limit.
You should also be able to add a line like this to limits.conf:
* hard memlock 40000
That'll change the default setting for all users.
From the limits.conf manpage:
The syntax of the lines is as follows:
<domain> <type> <item> <value>
The fields listed above should be filled as follows:
<domain>
[snip]
· the wildcard *, for default entry.