Same problem as the one described in bug 1184536. When httpd service is started with mod_perl installed, /proc/[PID]/comm has different content than without it, rendering e.g. 'killall httpd' unusable.

# rpm -q mod_perl
package mod_perl is not installed
# systemctl start httpd
# for pid in `pgrep httpd`; do cat /proc/$pid/comm; done
httpd
httpd
httpd
httpd
httpd
httpd
# systemctl stop httpd
# yum install mod_perl
...
# systemctl start httpd
# for pid in `pgrep httpd`; do cat /proc/$pid/comm; done
/usr/sbin/httpd
/usr/sbin/httpd
/usr/sbin/httpd
/usr/sbin/httpd
/usr/sbin/httpd
/usr/sbin/httpd

Version-Release number of selected component (if applicable):
mod_perl-2.0.8-10.20140624svn1602105.el7.x86_64
httpd-2.4.6-31.el7.x86_64

+++ This bug was initially created as a clone of Bug #1184536 +++