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| author | KOSAKI Motohiro <kosaki.motohiro@gmail.com> | 2012-10-08 16:29:14 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-13 05:38:56 +0900 |
| commit | 14cfd9f986d521f3f97139fa2ae5db67886059d1 (patch) | |
| tree | ecef4bf5f2993d525f676b56ae025125fe1036a6 /mm | |
| parent | 160f00fefef1e5b72be0745236d2b65d14b99ed4 (diff) | |
| download | lwn-14cfd9f986d521f3f97139fa2ae5db67886059d1.tar.gz lwn-14cfd9f986d521f3f97139fa2ae5db67886059d1.zip | |
revert "mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages"
commit 8d34694c1abf29df1f3c7317936b7e3e2e308d9b upstream.
Commit 05f144a0d5c2 ("mm: mempolicy: Let vma_merge and vma_split handle
vma->vm_policy linkages") removed vma->vm_policy updates code but it is
the purpose of mbind_range(). Now, mbind_range() is virtually a no-op
and while it does not allow memory corruption it is not the right fix.
This patch is a revert.
[mgorman@suse.de: Edited changelog]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mempolicy.c | 41 |
1 files changed, 24 insertions, 17 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 9afcbad632ec..ed3cc1bea49b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -607,6 +607,27 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end, return first; } +/* Apply policy to a single VMA */ +static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) +{ + int err = 0; + struct mempolicy *old = vma->vm_policy; + + pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", + vma->vm_start, vma->vm_end, vma->vm_pgoff, + vma->vm_ops, vma->vm_file, + vma->vm_ops ? vma->vm_ops->set_policy : NULL); + + if (vma->vm_ops && vma->vm_ops->set_policy) + err = vma->vm_ops->set_policy(vma, new); + if (!err) { + mpol_get(new); + vma->vm_policy = new; + mpol_put(old); + } + return err; +} + /* Step 2: apply policy to a range and do splits. */ static int mbind_range(struct mm_struct *mm, unsigned long start, unsigned long end, struct mempolicy *new_pol) @@ -655,23 +676,9 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, if (err) goto out; } - - /* - * Apply policy to a single VMA. The reference counting of - * policy for vma_policy linkages has already been handled by - * vma_merge and split_vma as necessary. If this is a shared - * policy then ->set_policy will increment the reference count - * for an sp node. - */ - pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", - vma->vm_start, vma->vm_end, vma->vm_pgoff, - vma->vm_ops, vma->vm_file, - vma->vm_ops ? vma->vm_ops->set_policy : NULL); - if (vma->vm_ops && vma->vm_ops->set_policy) { - err = vma->vm_ops->set_policy(vma, new_pol); - if (err) - goto out; - } + err = policy_vma(vma, new_pol); + if (err) + goto out; } out: |