From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx124.postini.com [74.125.245.124]) by kanga.kvack.org (Postfix) with SMTP id CC6F66B0070 for ; Mon, 15 Oct 2012 02:00:36 -0400 (EDT) From: "Kirill A. Shutemov" Subject: [PATCH v4 05/10] thp: change_huge_pmd(): keep huge zero page write-protected Date: Mon, 15 Oct 2012 09:00:54 +0300 Message-Id: <1350280859-18801-6-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: <1350280859-18801-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1350280859-18801-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Andrea Arcangeli , linux-mm@kvack.org Cc: Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , "Kirill A. Shutemov" From: "Kirill A. Shutemov" 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 --- 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org