提交 ef694222 编写于 作者: B Bob Liu 提交者: Linus Torvalds

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: NBob Liu <lliubbo@gmail.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 cc9a6c87
......@@ -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);
......
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