CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Force Feroceon L2 cache write through


Linux Kernel Configuration
└─>Force Feroceon L2 cache write through
In linux kernel since version 2.6.28 (release Date: 2008-12-24)  
Say Y here to use the Feroceon L2 cache in writethrough mode.
Unless you specifically require this, say N for writeback mode.