CONFIG_MSPEC is not available for thedefaultarchitecture x86.
Result is shown for architecture ia64

Memory special operations driver

modulename: mspec.ko

configname: CONFIG_MSPEC

Linux Kernel Configuration
└─>Memory special operations driver
In linux kernel since version 2.6.19 (release Date: 2006-11-29)  
If you have an ia64 and you want to enable memory special
operations support (formerly known as fetchop), say Y here,
otherwise say N.

source code: