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Commit ef694222 authored by Bob Liu's avatar Bob Liu Committed by Linus Torvalds
Browse files

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: default avatarBob Liu <lliubbo@gmail.com>
Acked-by: default avatarHugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cc9a6c87

mm/ksm.c

+19 −15
Original line number Original line Diff line number Diff line
@@ -374,6 +374,20 @@ static int break_ksm(struct vm_area_struct *vma, unsigned long addr) 
	return (ret & VM_FAULT_OOM) ? -ENOMEM : 0;

	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)

static void break_cow(struct rmap_item *rmap_item)

{

{

	struct mm_struct *mm = rmap_item->mm;

	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);

	put_anon_vma(rmap_item->anon_vma);





	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_sem);

	if (ksm_test_exit(mm))

	vma = find_mergeable_vma(mm, addr);

		goto out;

	if (vma)

	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);

		break_ksm(vma, addr);

out:

	up_read(&mm->mmap_sem);

	up_read(&mm->mmap_sem);

}

}
@@ -421,12 +429,8 @@ static struct page *get_mergeable_page(struct rmap_item *rmap_item) 
	struct page *page;

	struct page *page;





	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_sem);

	if (ksm_test_exit(mm))

	vma = find_mergeable_vma(mm, addr);

		goto out;

	if (!vma)

	vma = find_vma(mm, addr);

	if (!vma || vma->vm_start > addr)

		goto out;

	if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)

		goto out;

		goto out;





	page = follow_page(vma, addr, FOLL_GET);

	page = follow_page(vma, addr, FOLL_GET);