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

Set custom consistent memory pool size

configname: CONFIG_CONSISTENT_SIZE_BOOL

Linux Kernel Configuration
└─>Advanced setup
└─>Set custom consistent memory pool size
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
This option allows you to set the size of the
consistent memory pool. This pool of virtual memory
is used to make consistent memory allocations.