CONFIG_SINGLE_MEMORY_CHUNK is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

Use one physical chunk of memory only

configname: CONFIG_SINGLE_MEMORY_CHUNK

Linux/68k Kernel Configuration
└─>Platform dependent setup
└─>Use one physical chunk of memory only
In linux kernel since version 2.6.12  
Ignore all but the first contiguous chunk of physical memory for VM
purposes. This will save a few bytes kernel size and may speed up
some operations. Say N if not sure.