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authorBob Liu <lliubbo@gmail.com>2012-03-21 16:34:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-21 17:54:59 -0700
commitef6942224a185c9e434f6cfe69fe434e732f5b38 (patch)
treee26664dbfd6077129d75f555757d36b5fbec43c2 /mm/ksm.c
parentcc9a6c8776615f9c194ccf0b63a0aa5628235545 (diff)
downloadlwn-ef6942224a185c9e434f6cfe69fe434e732f5b38.tar.gz
lwn-ef6942224a185c9e434f6cfe69fe434e732f5b38.zip
ksm: cleanup: introduce find_mergeable_vma()
There are multiple places which perform the same check. Add a new find_mergeable_vma() to handle this. Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/ksm.c')
-rw-r--r--mm/ksm.c34
1 files changed, 19 insertions, 15 deletions
diff --git a/mm/ksm.c b/mm/ksm.c
index a6d3fb7e6c10..47c885368890 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -374,6 +374,20 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
return (ret & VM_FAULT_OOM) ? -ENOMEM : 0;
}
+static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm,
+ unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ if (ksm_test_exit(mm))
+ return NULL;
+ vma = find_vma(mm, addr);
+ if (!vma || vma->vm_start > addr)
+ return NULL;
+ if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+ return NULL;
+ return vma;
+}
+
static void break_cow(struct rmap_item *rmap_item)
{
struct mm_struct *mm = rmap_item->mm;
@@ -387,15 +401,9 @@ static void break_cow(struct rmap_item *rmap_item)
put_anon_vma(rmap_item->anon_vma);
down_read(&mm->mmap_sem);
- if (ksm_test_exit(mm))
- goto out;
- vma = find_vma(mm, addr);
- if (!vma || vma->vm_start > addr)
- goto out;
- if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
- goto out;
- break_ksm(vma, addr);
-out:
+ vma = find_mergeable_vma(mm, addr);
+ if (vma)
+ break_ksm(vma, addr);
up_read(&mm->mmap_sem);
}
@@ -421,12 +429,8 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item)
struct page *page;
down_read(&mm->mmap_sem);
- if (ksm_test_exit(mm))
- goto out;
- vma = find_vma(mm, addr);
- if (!vma || vma->vm_start > addr)
- goto out;
- if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+ vma = find_mergeable_vma(mm, addr);
+ if (!vma)
goto out;
page = follow_page(vma, addr, FOLL_GET);