CONFIG_LARGE_ALLOCS is not available for thedefaultarchitecture x86.
Result is shown for architecture m68knommu
default or selected kernelversion does not have config value CONFIG_LARGE_ALLOCS.
Result is shown for kernelversion 5.4.123

Allow allocating large blocks (> 1MB) of memory

configname: CONFIG_LARGE_ALLOCS

uClinux/68k (w/o MMU) Kernel Configuration
└─>Processor type and features
└─>Allow allocating large blocks (> 1MB) of memory
In linux kernel since version 2.6.12  
Allow the slab memory allocator to keep chains for very large
memory sizes - upto 32MB. You may need this if your system has
a lot of RAM, and you need to able to allocate very large
contiguous chunks. If unsure, say N.