[PATCH v4 05/10] thp: change_huge_pmd(): keep huge zero page write-protected
From: Kirill A. Shutemov <hidden>
Date: 2012-10-15 06:00:42
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lkml
Subsystem:
memory management, memory management - thp (transparent huge page), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds
From: "Kirill A. Shutemov" <redacted> We want to get page fault on write attempt to huge zero page, so let's keep it write-protected. Signed-off-by: Kirill A. Shutemov <redacted> --- mm/huge_memory.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 76548b1..8dbb1e4 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c@@ -1258,6 +1258,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, pmd_t entry; entry = pmdp_get_and_clear(mm, addr, pmd); entry = pmd_modify(entry, newprot); + if (is_huge_zero_pmd(entry)) + entry = pmd_wrprotect(entry); set_pmd_at(mm, addr, pmd, entry); spin_unlock(&vma->vm_mm->page_table_lock); ret = 1;
--
1.7.7.6
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