CONFIG_ARCH_SPARSEMEM_ENABLE (not configurable)

configname: CONFIG_ARCH_SPARSEMEM_ENABLE

Linux Kernel Configuration for x86
└─>Processor type and features
└─>ARCH_SPARSEMEM_ENABLE
In linux kernel since version 2.6.13 (release Date: 2005-08-28)  

depends
CONFIG_NUMA or CONFIG_EXPERIMENTAL
CONFIG_X86_64 or CONFIG_X86_PC