From patchwork Thu May 30 20:34:56 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 247730 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id B1C0B2C00A7 for ; Fri, 31 May 2013 06:36:39 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Ui9aL-0003i2-KL; Thu, 30 May 2013 20:36:33 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Ui9Yp-0002ut-S6 for kernel-team@lists.ubuntu.com; Thu, 30 May 2013 20:34:59 +0000 Received: from c-67-160-231-42.hsd1.ca.comcast.net ([67.160.231.42] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Ui9Yp-0002l6-GM; Thu, 30 May 2013 20:34:59 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1Ui9Yn-0003Px-0T; Thu, 30 May 2013 13:34:57 -0700 From: Kamal Mostafa To: "Aneesh Kumar K.V" Subject: [ 3.8.y.z extended stable ] Patch "mm/THP: use pmd_populate() to update the pmd with pgtable_t pointer" has been added to staging queue Date: Thu, 30 May 2013 13:34:56 -0700 Message-Id: <1369946096-13105-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 X-Extended-Stable: 3.8 Cc: Andrea Arcangeli , Benjamin Herrenschmidt , Kamal Mostafa , Hugh Dickins , kernel-team@lists.ubuntu.com, Andrew Morton , Linus Torvalds X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled mm/THP: use pmd_populate() to update the pmd with pgtable_t pointer to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.2. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 096ad310f6b99c2315a91677645d6d9ed7836427 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 24 May 2013 15:55:21 -0700 Subject: mm/THP: use pmd_populate() to update the pmd with pgtable_t pointer commit 7c3425123ddfdc5f48e7913ff59d908789712b18 upstream. We should not use set_pmd_at to update pmd_t with pgtable_t pointer. set_pmd_at is used to set pmd with huge pte entries and architectures like ppc64, clear few flags from the pte when saving a new entry. Without this change we observe bad pte errors like below on ppc64 with THP enabled. BUG: Bad page map in process ld mm=0xc000001ee39f4780 pte:7fc3f37848000001 pmd:c000001ec0000000 Signed-off-by: Aneesh Kumar K.V Cc: Hugh Dickins Cc: Benjamin Herrenschmidt Reviewed-by: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- mm/huge_memory.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) -- 1.8.1.2 diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b795dcf..9459edd 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2366,7 +2366,12 @@ static void collapse_huge_page(struct mm_struct *mm, pte_unmap(pte); spin_lock(&mm->page_table_lock); BUG_ON(!pmd_none(*pmd)); - set_pmd_at(mm, address, pmd, _pmd); + /* + * We can only use set_pmd_at when establishing + * hugepmds and never for establishing regular pmds that + * points to regular pagetables. Use pmd_populate for that + */ + pmd_populate(mm, pmd, pmd_pgtable(_pmd)); spin_unlock(&mm->page_table_lock); anon_vma_unlock_write(vma->anon_vma); goto out;