From ef6942224a185c9e434f6cfe69fe434e732f5b38 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Wed, 21 Mar 2012 16:34:11 -0700 Subject: [PATCH] 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 Acked-by: Hugh Dickins Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/ksm.c | 34 +++++++++++++++++++--------------- 1 file 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);