I'm running a linux web server that uses apache, php, and suphp. Each time a guest accesses the server, suphp is started, the php interpreter is started and the php file is processed, but all of these files are on the disk.
I want to make it so that when the suphp and php programs start for the first time, they get cached in memory, and then the next time (and times after that) they try to start again, they will load from memory, making the startup time much smaller.
I think there is a setting inside /proc somewhere that can help me with this, but I'm not sure which one.
What you're trying to change is an aspect of application behavior, not kernel behavior, so there is nothing in /proc that will help you.
PHP opcode caching is not available under suPHP. You will need to use something else (possibly mod_php or FastCGI) to take advantage of it.