pmd_t *pmd = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);  return pmd;
return pgtable_quicklist_alloc();
pmd_alloc_one (struct mm_struct *mm, unsigned long addr){	pmd_t *pmd = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);	return pmd;}