[PATCH v4 2/3] thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE

From: Naoya Horiguchi
Date: Mon Mar 12 2012 - 18:32:12 EST


These macros will be used in later patch, where all usage are expected
to be optimized away without #ifdef CONFIG_TRANSPARENT_HUGEPAGE.
But to detect unexpected usages, we convert existing BUG() to BUILD_BUG().

Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Acked-by: Hillf Danton <dhillf@xxxxxxxxx>
Reviewed-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
---
include/linux/huge_mm.h | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)

diff --git linux-next-20120307.orig/include/linux/huge_mm.h linux-next-20120307/include/linux/huge_mm.h
index f56cacb..c8af7a2 100644
--- linux-next-20120307.orig/include/linux/huge_mm.h
+++ linux-next-20120307/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

--
1.7.7.6

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