CONFIG_ARCH_DISCONTIGMEM_ENABLE is not available for thedefaultarchitecture x86.
Result is shown for architecture m32r

Internal RAM Support

configname: CONFIG_ARCH_DISCONTIGMEM_ENABLE

Linux/M32R Kernel Configuration
└─>Processor type and features
└─>Internal RAM Support
In linux kernel since version 2.6.13 (release Date: 2005-08-28)