CONFIG_KERNEL_STACK_ORDER is not available for thedefaultarchitecture x86.
Result is shown for architecture um

Kernel stack size order


Linux Kernel Configuration
└─>UML-specific options
└─>Kernel stack size order
In linux kernel since version 2.6.12  
This option determines the size of UML kernel stacks. They will
be 1 << order pages. The default is OK unless you're running Valgrind
on UML, in which case, set this to 3.
It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
increase in the size of the state which needs to be saved when handling