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authorAndrea Arcangeli <aarcange@redhat.com>2010-09-22 13:05:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-09-22 17:22:39 -0700
commita247c3a97a0216b18a46243eda26081f1928ec37 (patch)
treeecf6996b252e9cc818d170eba4b8eb25aac3d596 /kernel/fork.c
parentdf08cdc7ef606509debe7677c439be0ca48790e4 (diff)
rmap: fix walk during fork
The below bug in fork led to the rmap walk finding the parent huge-pmd twice instead of just once, because the anon_vma_chain objects of the child vma still point to the vma->vm_mm of the parent. The patch fixes it by making the rmap walk accurate during fork. It's not a big deal normally but it worth being accurate considering the cost is the same. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <jweiner@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index b7e9d60a675d..c445f8cc408d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -356,10 +356,10 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (IS_ERR(pol))
goto fail_nomem_policy;
vma_set_policy(tmp, pol);
+ tmp->vm_mm = mm;
if (anon_vma_fork(tmp, mpnt))
goto fail_nomem_anon_vma_fork;
tmp->vm_flags &= ~VM_LOCKED;
- tmp->vm_mm = mm;
tmp->vm_next = tmp->vm_prev = NULL;
file = tmp->vm_file;
if (file) {