From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH 0/4] thp: fix few MADV_DONTNEED races
Date: Thu, 2 Mar 2017 18:10:30 +0300 [thread overview]
Message-ID: <20170302151034.27829-1-kirill.shutemov@linux.intel.com> (raw)
For MADV_DONTNEED to work properly with huge pages, it's critical to not clear
pmd intermittently unless you hold down_write(mmap_sem). Otherwise
MADV_DONTNEED can miss the THP which can lead to userspace breakage.
See example of such race in commit message of patch 2/4.
All these races are found by code inspection. I haven't seen them triggered.
I don't think it's worth to apply them to stable@.
Kirill A. Shutemov (4):
thp: reduce indentation level in change_huge_pmd()
thp: fix MADV_DONTNEED vs. numa balancing race
thp: fix MADV_DONTNEED vs. MADV_FREE race
thp: fix MADV_DONTNEED vs clear soft dirty race
fs/proc/task_mmu.c | 9 +++++-
mm/huge_memory.c | 86 ++++++++++++++++++++++++++++++++++++------------------
2 files changed, 66 insertions(+), 29 deletions(-)
--
2.11.0
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next reply other threads:[~2017-03-02 15:11 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-02 15:10 Kirill A. Shutemov [this message]
2017-03-02 15:10 ` [PATCH 1/4] thp: reduce indentation level in change_huge_pmd() Kirill A. Shutemov
2017-04-12 11:37 ` Vlastimil Babka
2017-03-02 15:10 ` [PATCH 2/4] thp: fix MADV_DONTNEED vs. numa balancing race Kirill A. Shutemov
2017-03-03 17:17 ` Dave Hansen
2017-04-12 13:33 ` Vlastimil Babka
2017-05-16 14:54 ` Vlastimil Babka
2017-05-16 20:29 ` Andrea Arcangeli
2017-05-23 12:42 ` Vlastimil Babka
2017-06-09 8:21 ` Vlastimil Babka
2017-03-02 15:10 ` [PATCH 3/4] thp: fix MADV_DONTNEED vs. MADV_FREE race Kirill A. Shutemov
2017-03-03 5:35 ` Hillf Danton
2017-03-03 10:26 ` Kirill A. Shutemov
2017-03-06 1:44 ` Minchan Kim
2017-03-07 14:04 ` Kirill A. Shutemov
2017-03-08 6:17 ` Minchan Kim
2017-03-06 2:49 ` Aneesh Kumar K.V
2017-03-07 13:52 ` Kirill A. Shutemov
2017-03-02 15:10 ` [PATCH 4/4] thp: fix MADV_DONTNEED vs clear soft dirty race Kirill A. Shutemov
2017-03-03 22:29 ` Andrew Morton
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