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author | Wei Yang <richardw.yang@linux.intel.com> | 2019-11-30 17:50:56 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-01 06:29:19 -0800 |
commit | 47b390d23bf81894395c8773acf6f73c66465dc4 (patch) | |
tree | 40d7190a134cabb8c87ce679fd72271f45be9955 /mm/z3fold.c | |
parent | aba6dfb75fe15650991442efd137c32fbf2e2b85 (diff) | |
download | linux-47b390d23bf81894395c8773acf6f73c66465dc4.tar.bz2 |
mm/rmap.c: don't reuse anon_vma if we just want a copy
Before commit 7a3ef208e662 ("mm: prevent endless growth of anon_vma
hierarchy"), anon_vma_clone() doesn't change dst->anon_vma. While after
this commit, anon_vma_clone() will try to reuse an exist one on forking.
But this commit go a little bit further for the case not forking.
anon_vma_clone() is called from __vma_split(), __split_vma(), copy_vma()
and anon_vma_fork(). For the first three places, the purpose here is
get a copy of src and we don't expect to touch dst->anon_vma even it is
NULL.
While after that commit, it is possible to reuse an anon_vma when
dst->anon_vma is NULL. This is not we intend to have.
This patch stops reuse of anon_vma for non-fork cases.
Link: http://lkml.kernel.org/r/20191011072256.16275-1-richardw.yang@linux.intel.com
Fixes: 7a3ef208e662 ("mm: prevent endless growth of anon_vma hierarchy")
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/z3fold.c')
0 files changed, 0 insertions, 0 deletions