[PATCH v17 2/7] x86: add pmd_[dirty|mkclean] for THP

From: Minchan Kim
Date: Mon Oct 20 2014 - 06:12:09 EST


MADV_FREE needs pmd_dirty and pmd_mkclean for detecting recent
overwrite of the contents since MADV_FREE syscall is called for
THP page.

This patch adds pmd_dirty and pmd_mkclean for THP page MADV_FREE
support.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx

Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Acked-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
arch/x86/include/asm/pgtable.h | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index aa97a070f09f..2259de0ccd79 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -104,6 +104,11 @@ static inline int pmd_young(pmd_t pmd)
return pmd_flags(pmd) & _PAGE_ACCESSED;
}

+static inline int pmd_dirty(pmd_t pmd)
+{
+ return pmd_flags(pmd) & _PAGE_DIRTY;
+}
+
static inline int pte_write(pte_t pte)
{
return pte_flags(pte) & _PAGE_RW;
@@ -272,6 +277,11 @@ static inline pmd_t pmd_mkold(pmd_t pmd)
return pmd_clear_flags(pmd, _PAGE_ACCESSED);
}

+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+ return pmd_clear_flags(pmd, _PAGE_DIRTY);
+}
+
static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
return pmd_clear_flags(pmd, _PAGE_RW);
--
2.0.0

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