When you are done recompiling php/apache on the server, you receive an error as below when accessing the domain.
[Sat Aug 03 03:27:44 2013] [error] [client xx.xx.xx.xx] /usr/bin/php: error while loading shared libraries: libXau.so.6: failed to map segment from shared object: Cannot allocate memory, referer: http://domain.com/
[Sat Aug 03 03:27:44 2013] [error] [client xx.xx.xx.xx] Premature end of script headers: index.php, referer: http://domain.com/
[Sat Aug 03 03:27:45 2013] [error] [client xx.xx.xx.xx] File does not exist: /home/xyz/public_html/abc/sys_cpanel, referer: http://domian.com/abc/
Open the apache config file and comment RLimitMEM. Save the file and restart apache. RLimitMEM Limits the memory consumption of processes launched by Apache httpd children.