CONFIG_SPARC64_PAGE_SIZE_512KB is not available for thedefaultarchitecture x86.
Result is shown for architecture sparc64
default or selected kernelversion does not have config value CONFIG_SPARC64_PAGE_SIZE_512KB.
Result is shown for kernelversion 5.4.123

512KB

configname: CONFIG_SPARC64_PAGE_SIZE_512KB

Kernel page size
└─>512KB
In linux kernel since version 2.6.12