PG_M
if (!check_only && writable && (pte32 & PG_M) == 0) {
pte32, pte32 | PG_M) == 0) {
if (!check_only && writable && (pte & PG_M) == 0) {
if (atomic_cmpset_64(&ptpbase[ptpindex], pte, pte | PG_M) == 0)