How to set cache coherent or none coherent?

I am developing for HiFive Unleashed borad.

I am developing my original RTOS.
I want to run independently per COREs.
So that I want none coherent cache mode.

Ex. On ARM processor, cache shareble or nonshareble setting.

How to set cache coherent or none coherent?

Why do you want non-coherent memory? Just run the programs on non-overlapping memory and they will not share the memory.

Ithink,
Overhead available on coherent memory against non-coherent memory.
It’s nothing?

If only one processor is accessing some address range then that address range can not find itself in the cache of any other processor, and thus there is no overhead.

OK.
Thank you for all.