Profiling Apache with LD_PRELOAD

["Nedeljko Vasic" <vasic.nedeljko@xxxxxxxxx>]

I'm trying to profile Apache Web server 2.2.8 on my Debian machine. Precisely, I need to measure mean values and standard deviations for each system call. At this point, T'm using LD_PRELOAD environment variable to create a simple imposer for system calls. I thought that using SetEnv directive within httpd.cong will help, but it wasn't the case. It only helps for cgi srcipts as stated here http://httpd.apache.org/docs/2.2/env.html. However, I still cannot catch any workers' activity. It seems to me that I need to find a sanitization place, where children are created. So, I inserted  setenv("LD_PRELOAD", "mylib.so",1) into make_child function of ./server/mpm/prefork/prefork.c but didn't get expected result. I think that apache is keep cleaning environment variables elsewhere. Could you please suggest my any potential approach, I'm pretty much desperate after a few days working on this :) All comments are more then welcome.

Cheers,
Nedeljko