[PATCHv4 01/12] asm-generic: Provide generic_pmdp_establish()

From
Kirill A. Shutemov <hidden>
Date
2017-12-13 10:59:11
Also in
linux-mm, lkml
Reply to
Kirill A. Shutemov, 2017-12-13
This is an implementation of pmdp_establish() that is only suitable for
an architecture that doesn't have hardware dirty/accessed bits. In this
case we can't race with CPU which sets these bits and non-atomic
approach is fine.

Signed-off-by: Kirill A. Shutemov <redacted>
---
 include/asm-generic/pgtable.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index b234d54f2cb6..ae83b14200b8 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -309,6 +309,21 @@ extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 #endif
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * This is an implementation of pmdp_establish() that is only suitable for an
+ * architecture that doesn't have hardware dirty/accessed bits. In this case we
+ * can't race with CPU which sets these bits and non-atomic aproach is fine.
+ */
+static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp, pmd_t pmd)
+{
+	pmd_t old_pmd = *pmdp;
+	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+	return old_pmd;
+}
+#endif
+
 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
 extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 			    pmd_t *pmdp);
-- 
2.15.0

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Thread (19 messages) 19 messages, 3 authors, last reply 2017-12-15
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