I have a process taking almost 100% CPU (according to top) but doing an
"strace -f -p PID_of_the_process" shows nothing, the process seems to be
sitting there doing nothing even tough its eating the CPU.

This particular process is part of a cgi script.

If I launch the script from the command line or from cron, and I send the
strace output to a file, the process ends normally and quickly.

If the process is running from a cgi-script, it misbehaves. And the strace
command output shows nothing after a certain point.

If I compare the output of the 2 strace files, they are identical with
regard to this program up to a certain system call (access) afterward, the
command line version continues, while the sci-script version does not call
"access", it's last system call is a read from a config file (the same as
the command line version, with the same result)

Any help appreciated, I have to troubleshoot this.