split_huge_pmd
split_huge_pmd(vma, pmd, addr);
split_huge_pmd(vmf->vma, vmf->pmd, vmf->address);
split_huge_pmd(vma, pmd, start);
split_huge_pmd(vma, pmd, address);
split_huge_pmd(vma, pmdp, addr);
split_huge_pmd(pmc->old, old_pmd, pmc->old_addr);
split_huge_pmd(walk->vma, pmd, addr);
split_huge_pmd(src_vma, src_pmd, src_addr);