Debug notifier call chains

configname: CONFIG_DEBUG_NOTIFIERS

Linux Kernel Configuration
└─>Kernel hacking
└─>Debug kernel data structures
└─>Debug notifier call chains
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Enable this to turn on sanity checking for notifier call chains.
This is most useful for kernel developers to make sure that
modules properly unregister themselves from notifier chains.
This is a relatively cheap check but if you care about maximum
performance, say N.