From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f70.google.com (mail-pl0-f70.google.com [209.85.160.70]) by kanga.kvack.org (Postfix) with ESMTP id 16EA46B0069 for ; Wed, 13 Dec 2017 05:58:10 -0500 (EST) Received: by mail-pl0-f70.google.com with SMTP id z3so903057plh.18 for ; Wed, 13 Dec 2017 02:58:10 -0800 (PST) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTPS id g188si1079666pgc.386.2017.12.13.02.58.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Dec 2017 02:58:09 -0800 (PST) From: "Kirill A. Shutemov" Subject: [PATCHv4 00/12] Do not lose dirty bit on THP pages Date: Wed, 13 Dec 2017 13:57:44 +0300 Message-Id: <20171213105756.69879-1-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Vlastimil Babka , Andrea Arcangeli , Michal Hocko , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Vlastimil noted that pmdp_invalidate() is not atomic and we can lose dirty and access bits if CPU sets them after pmdp dereference, but before set_pmd_at(). The bug can lead to data loss, but the race window is tiny and I haven't seen any reports that suggested that it happens in reality. So I don't think it worth sending it to stable. Unfortunately, there's no way to address the issue in a generic way. We need to fix all architectures that support THP one-by-one. All architectures that have THP supported have to provide atomic pmdp_invalidate() that returns previous value. If generic implementation of pmdp_invalidate() is used, architecture needs to provide atomic pmdp_estabish(). pmdp_estabish() is not used out-side generic implementation of pmdp_invalidate() so far, but I think this can change in the future. Aneesh Kumar K.V (2): powerpc/mm: update pmdp_invalidate to return old pmd value mm/thp: Remove pmd_huge_split_prepare Catalin Marinas (1): arm64: Provide pmdp_establish() helper Kirill A. Shutemov (7): asm-generic: Provide generic_pmdp_establish() arc: Use generic_pmdp_establish as pmdp_establish arm/mm: Provide pmdp_establish() helper mips: Use generic_pmdp_establish as pmdp_establish x86/mm: Provide pmdp_establish() helper mm: Do not lose dirty and access bits in pmdp_invalidate() mm: Use updated pmdp_invalidate() interface to track dirty/accessed bits Martin Schwidefsky (1): s390/mm: Modify pmdp_invalidate to return old value. Nitin Gupta (1): sparc64: Update pmdp_invalidate() to return old pmd value arch/arc/include/asm/hugepage.h | 3 + arch/arm/include/asm/pgtable-3level.h | 3 + arch/arm64/include/asm/pgtable.h | 7 +++ arch/mips/include/asm/pgtable.h | 3 + arch/powerpc/include/asm/book3s/64/hash-4k.h | 2 - arch/powerpc/include/asm/book3s/64/hash-64k.h | 2 - arch/powerpc/include/asm/book3s/64/pgtable.h | 13 +---- arch/powerpc/include/asm/book3s/64/radix.h | 6 -- arch/powerpc/mm/pgtable-book3s64.c | 7 ++- arch/powerpc/mm/pgtable-hash64.c | 22 ------- arch/s390/include/asm/pgtable.h | 4 +- arch/sparc/include/asm/pgtable_64.h | 2 +- arch/sparc/mm/tlb.c | 23 ++++++-- arch/x86/include/asm/pgtable-3level.h | 37 +++++++++++- arch/x86/include/asm/pgtable.h | 15 +++++ fs/proc/task_mmu.c | 8 +-- include/asm-generic/pgtable.h | 25 +++++--- mm/huge_memory.c | 83 ++++++++++++--------------- mm/pgtable-generic.c | 6 +- 19 files changed, 156 insertions(+), 115 deletions(-) -- 2.15.0 -- 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