From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33241 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752378AbcEBABz (ORCPT ); Sun, 1 May 2016 20:01:55 -0400 Subject: Patch "mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check" has been added to the 4.4-stable tree To: koct9i@gmail.com, aarcange@redhat.com, akpm@linux-foundation.org, dvyukov@google.com, gregkh@linuxfoundation.org, kirill.shutemov@linux.intel.com, torvalds@linux-foundation.org, vbabka@suse.cz Cc: , From: Date: Sun, 01 May 2016 17:01:54 -0700 Message-ID: <1462147314165226@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-huge_memory-replace-vm_no_thp-vm_bug_on-with-actual-vma-check.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 3486b85a29c1741db99d0c522211c82d2b7a56d0 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 28 Apr 2016 16:18:32 -0700 Subject: mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check From: Konstantin Khlebnikov commit 3486b85a29c1741db99d0c522211c82d2b7a56d0 upstream. Khugepaged detects own VMAs by checking vm_file and vm_ops but this way it cannot distinguish private /dev/zero mappings from other special mappings like /dev/hpet which has no vm_ops and popultes PTEs in mmap. This fixes false-positive VM_BUG_ON and prevents installing THP where they are not expected. Link: http://lkml.kernel.org/r/CACT4Y+ZmuZMV5CjSFOeXviwQdABAgT7T+StKfTqan9YDtgEi5g@mail.gmail.com Fixes: 78f11a255749 ("mm: thp: fix /dev/zero MAP_PRIVATE and vm_flags cleanups") Signed-off-by: Konstantin Khlebnikov Reported-by: Dmitry Vyukov Acked-by: Vlastimil Babka Acked-by: Kirill A. Shutemov Cc: Dmitry Vyukov Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/huge_memory.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2134,10 +2134,9 @@ int khugepaged_enter_vma_merge(struct vm * page fault if needed. */ return 0; - if (vma->vm_ops) + if (vma->vm_ops || (vm_flags & VM_NO_THP)) /* khugepaged not yet working on file or special mappings */ return 0; - VM_BUG_ON_VMA(vm_flags & VM_NO_THP, vma); hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; if (hstart < hend) @@ -2498,8 +2497,7 @@ static bool hugepage_vma_check(struct vm return false; if (is_vma_temporary_stack(vma)) return false; - VM_BUG_ON_VMA(vma->vm_flags & VM_NO_THP, vma); - return true; + return !(vma->vm_flags & VM_NO_THP); } static void collapse_huge_page(struct mm_struct *mm, Patches currently in stable-queue which might be from koct9i@gmail.com are queue-4.4/numa-fix-proc-pid-numa_maps-for-thp.patch queue-4.4/mm-huge_memory-replace-vm_no_thp-vm_bug_on-with-actual-vma-check.patch