Gentoo's Bugzilla –
Attachment 646866 Details for
Bug 729928x11-drivers/nvidia-drivers-450.51-r1 without CONFIG_MMU_NOTIFIER - .../work/kernel/nvidia-uvm/uvm8_va_space_mm.c:256:16: error: implicit declaration of function '__mmu_notifier_register'; did you mean 'uvm_mmu_notifier_register'?