CONFIG_IA64_UNCACHED_ALLOCATOR is not available for thedefaultarchitecture x86.
Result is shown for architecture ia64
default or selected kernelversion does not have config value CONFIG_IA64_UNCACHED_ALLOCATOR.
Result is shown for kernelversion 6.9.9

CONFIG_IA64_UNCACHED_ALLOCATOR (not configurable)

modulename: uncached.ko

configname: CONFIG_IA64_UNCACHED_ALLOCATOR

Linux Kernel Configuration
└─>Processor type and features
└─>IA64_UNCACHED_ALLOCATOR
In linux kernel since version 2.6.13 (release Date: 2005-08-28)  
source code:
arch/ia64/kernel/uncached.c

is depended by
CONFIG_MSPEC