[PATCH 6/8] thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()

From: Kirill A. Shutemov
Date: Tue Jun 11 2013 - 11:34:20 EST


From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>

It's confusing that mk_huge_pmd() has semantics different from mk_pte()
or mk_pmd(). I spent some time on debugging issue cased by this
inconsistency.

Let's move maybe_pmd_mkwrite() out of mk_huge_pmd() and adjust
prototype to match mk_pte().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3622e0be..5cd63f0 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -695,11 +695,10 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
return pmd;
}

-static inline pmd_t mk_huge_pmd(struct page *page, struct vm_area_struct *vma)
+static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot)
{
pmd_t entry;
- entry = mk_pmd(page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ entry = mk_pmd(page, prot);
entry = pmd_mkhuge(entry);
return entry;
}
@@ -732,7 +731,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
pte_free(mm, pgtable);
} else {
pmd_t entry;
- entry = mk_huge_pmd(page, vma);
+ entry = mk_huge_pmd(page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
page_add_new_anon_rmap(page, vma, haddr);
pgtable_trans_huge_deposit(mm, pmd, pgtable);
set_pmd_at(mm, haddr, pmd, entry);
@@ -1215,7 +1215,8 @@ alloc:
goto out_mn;
} else {
pmd_t entry;
- entry = mk_huge_pmd(new_page, vma);
+ entry = mk_huge_pmd(new_page, vma->vm_page_prot);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
pmdp_clear_flush(vma, haddr, pmd);
page_add_new_anon_rmap(new_page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
@@ -2361,7 +2362,8 @@ static void collapse_huge_page(struct mm_struct *mm,
__SetPageUptodate(new_page);
pgtable = pmd_pgtable(_pmd);

- _pmd = mk_huge_pmd(new_page, vma);
+ _pmd = mk_huge_pmd(new_page, vma->vm_page_prot);
+ _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);

/*
* spin_lock() below is not the equivalent of smp_wmb(), so
--
1.7.10.4

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