thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE

These macros will be used in a later patch, where all usages are expected to be optimized away without #ifdef CONFIG_TRANSPARENT_HUGEPAGE. But to detect unexpected usages, we convert the existing BUG() to BUILD_BUG(). [[email protected]: fix build in mm/pgtable-generic.c] Signed-off-by: Naoya Horiguchi <[email protected]> Acked-by: Hillf Danton <[email protected]> Reviewed-by: Andrea Arcangeli <[email protected]> Reviewed-by: KAMEZAWA Hiroyuki <[email protected]> Acked-by: David Rientjes <[email protected]> Cc: Daisuke Nishimura <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
adn770 · Mar 22, 2012 · d8c37c4 · d8c37c4
1 parent 8d32ff8
commit d8c37c4
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Showing 2 changed files with 9 additions and 7 deletions.
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
@@ -51,6 +51,9 @@ extern pmd_t *page_check_address_pmd(struct page *page,
 				     unsigned long address,
 				     enum page_check_address_pmd_flag flag);
 
+#define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
+#define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
 #define HPAGE_PMD_MASK HPAGE_MASK
@@ -102,8 +105,6 @@ extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
 		BUG_ON(pmd_trans_splitting(*____pmd) ||			\
 		       pmd_trans_huge(*____pmd));			\
 	} while (0)
-#define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
-#define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
 #if HPAGE_PMD_ORDER > MAX_ORDER
 #error "hugepages can't be allocated by the buddy allocator"
 #endif
@@ -158,9 +159,9 @@ static inline struct page *compound_trans_head(struct page *page)
 	return page;
 }
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
-#define HPAGE_PMD_SHIFT ({ BUG(); 0; })
-#define HPAGE_PMD_MASK ({ BUG(); 0; })
-#define HPAGE_PMD_SIZE ({ BUG(); 0; })
+#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
+#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
+#define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 
 #define hpage_nr_pages(x) 1
 

diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
@@ -70,10 +70,11 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma,
 			   unsigned long address, pmd_t *pmdp)
 {
 	int young;
-#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+#else
 	BUG();
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 	young = pmdp_test_and_clear_young(vma, address, pmdp);
 	if (young)
 		flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);