mm anon rmap: remove anon_vma_moveto_tail

mremap() had a clever optimization where move_ptes() did not take the
anon_vma lock to avoid a race with anon rmap users such as page migration.
 Instead, the avc's were ordered in such a way that the origin vma was
always visited by rmap before the destination.  This ordering and the use
of page table locks rmap usage safe.  However, we want to replace the use
of linked lists in anon rmap with an interval tree, and this will make it
harder to impose such ordering as the interval tree will always be sorted
by the avc->vma->vm_pgoff value.  For now, let's replace the
anon_vma_moveto_tail() ordering function with proper anon_vma locking in
move_ptes().  Once we have the anon interval tree in place, we will
re-introduce an optimization to avoid taking these locks in the most
common cases.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 3fce545df39..7f32cec57e6 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -120,7 +120,6 @@ void anon_vma_init(void);	/* create anon_vma_cachep */
 int  anon_vma_prepare(struct vm_area_struct *);
 void unlink_anon_vmas(struct vm_area_struct *);
 int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *);
-void anon_vma_moveto_tail(struct vm_area_struct *);
 int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *);
 
 static inline void anon_vma_merge(struct vm_area_struct *vma,