__contpte_try_unfold
extern void __contpte_try_unfold(struct mm_struct *mm, unsigned long addr,
__contpte_try_unfold(mm, addr, ptep, pte);
__contpte_try_unfold(mm, addr, ptep, orig_pte);
EXPORT_SYMBOL_GPL(__contpte_try_unfold);
__contpte_try_unfold(vma->vm_mm, addr, ptep, orig_pte);