CONFIG_CP15_BARRIER_EMULATION is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Emulate CP15 Barrier instructions


Linux Kernel Configuration
└─>Kernel Features
└─>Kernel support for 32-bit EL0
└─>Emulate deprecated/obsolete ARMv8 instructions
└─>Emulate CP15 Barrier instructions
In linux kernel since version 3.10 (release Date: 2013-06-30)  
The CP15 barrier instructions - CP15ISB, CP15DSB, and
CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
strongly recommended to use the ISB, DSB, and DMB
instructions instead.

Say Y here to enable software emulation of these
instructions for AArch32 userspace code. When this option is
enabled, CP15 barrier usage is traced which can help
identify software that needs updating. This feature can be
controlled at runtime with the abi.cp15_barrier sysctl.

If unsure, say Y