[PATCH 1/5] revert "mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages"
From: Mel Gorman <mgorman@suse.de>
Date: 2012-10-09 16:58:53
Also in:
lkml
Subsystem:
memory management, memory management - memory policy and migration, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: KOSAKI Motohiro <redacted>
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 <redacted>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <redacted>
Cc: Josh Boyer <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
mm/mempolicy.c | 41 ++++++++++++++++++++++++-----------------
1 file changed, 24 insertions(+), 17 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4ada3be..92daa26 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:
--
1.7.9.2
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