-#define pmd_alloc(mm, pud, address) \
-({ pmd_t *ret; \
- if (pgd_none(*pud)) \
- ret = __pmd_alloc(mm, pud, address); \
- else \
- ret = pmd_offset(pud, address); \
- ret; \
-})
+#define pmd_alloc(mm, pud, address) \
+ ((unlikely(pgd_none(*(pud))) && __pmd_alloc(mm, pud, address))? \
+ NULL: pmd_offset(pud, address))