CentOS ,I found this tutorial on the internet :
Install mod_perl Under Apache 2
If you already have an apache 2.2 (or later) web server and perl 5.8.8 (or later) installed, you may be able to add mod_perl support without recompiling apache2. The first step is to download and extract the mod_perl source code.
$ wget http://perl.apache.org/dist/mod_perl-2.0-current.tar.gz
$ tar -xvzf mod_perl-2.0-current.tar.gz
$ cd mod_perl-2.0.2
You'll want to note the location of your apache 2.2 installation root now. Mine happens to be under /opt/apache2.2/ but that's just me. You should replace the path I'm using with the path to your own Apache 2.2 installation root in all these examples.
As part of the configuration you must specify the full path to the apache installation root. Run the configuration script, and enter the correct information for your own system...
$ perl Makefile.PL MP_AP_PREFIX=/opt/apache2.2/
As noted in the output printed by the configuration script, the mod_perl apache module will eventually be installed in the modules directory, so add the following line to your apache conf/http.conf file...
LoadModule perl_module modules/mod_perl.so
Now compile and install mod_perl...
$ make && make test
$ sudo make install
You can check that the mod_perl.so file was actually installed in apache's modules directory. If it was and you had no error messages: congratulations! You've now got mod_perl installed. You can restart apache now or continue on with the next step.