mm, thp: Do not make page table dirty unconditionally in touch_p[mu]d()

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commit a8f9736645 upstream.

Currently, we unconditionally make page table dirty in touch_pmd().
It may result in false-positive can_follow_write_pmd().

We may avoid the situation, if we would only make the page table entry
dirty if caller asks for write access -- FOLL_WRITE.

The patch also changes touch_pud() in the same way.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Kirill A. Shutemov 2017-11-27 06:21:25 +03:00 • committed by Greg Kroah-Hartman

parent 786b924d39

commit 01ca972745

1 changed files with 13 additions and 23 deletions

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mm/huge_memory.c

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