../mm/ksm.c:2133:13: error: implicit declaration of function 'cma_page'; did you mean 'vma_pages'?

[sanderhollaar]

Compiling Current Linux kernel for Odroid C5 on NixOS fails with:

../mm/ksm.c: In function 'cmp_and_merge_page':
../mm/ksm.c:2133:13: error: implicit declaration of function 'cma_page'; did you mean 'vma_pages'? [-Werror=implicit-function-declaration]
 2133 |         if (cma_page(page)) {
      |             ^~~~~~~~
      |             vma_pages

I notice I have multiple issues compiling this kernel. Am I holding this wrong somehow?