Extend memmap on extra space for more information on page

modulename: page_ext.ko

configname: CONFIG_PAGE_EXTENSION

Linux Kernel Configuration
└─>Memory Debugging
└─>Extend memmap on extra space for more information on page
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Extend memmap on extra space for more information on page. This
could be used for debugging features that need to insert extra
field for every page. This extension enables us to save memory
by not allocating this extra memory according to boottime
configuration.

source code: