Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCH, RFC 5/9] thp: change_huge_pmd(): keep huge zero page write-protected | Date | Thu, 9 Aug 2012 12:08:16 +0300 |
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From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
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 <kirill.shutemov@linux.intel.com> --- 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 f5029d4..4001f1a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1248,6 +1248,8 @@ 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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