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authorBob Liu <lliubbo@gmail.com>2012-12-11 16:00:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 17:22:22 -0800
commit6219049ae1ce32b89236646cccaec2a5fc6c4fd2 (patch)
tree551e8b1d53b8d237678c96cb9b442c746609cfcd /mm/rmap.c
parent344aa35c27acdf70d3c67b5aa7cb6aa8585f80c1 (diff)
mm: introduce mm_find_pmd()
Several place need to find the pmd by(mm_struct, address), so introduce a function to simplify it. [akpm@linux-foundation.org: fix warning] Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Ni zhan Chen <nizhan.chen@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c48
1 files changed, 25 insertions, 23 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 2ee1ef0f317b..46823fb0e801 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -562,6 +562,27 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
return address;
}
+pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd = NULL;
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ pmd = NULL;
+out:
+ return pmd;
+}
+
/*
* Check that @page is mapped at @address into @mm.
*
@@ -574,8 +595,6 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
unsigned long address, spinlock_t **ptlp, int sync)
{
- pgd_t *pgd;
- pud_t *pud;
pmd_t *pmd;
pte_t *pte;
spinlock_t *ptl;
@@ -586,17 +605,10 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
goto check;
}
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
- return NULL;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
+ pmd = mm_find_pmd(mm, address);
+ if (!pmd)
return NULL;
- pmd = pmd_offset(pud, address);
- if (!pmd_present(*pmd))
- return NULL;
if (pmd_trans_huge(*pmd))
return NULL;
@@ -1345,8 +1357,6 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
struct vm_area_struct *vma, struct page *check_page)
{
struct mm_struct *mm = vma->vm_mm;
- pgd_t *pgd;
- pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pte_t pteval;
@@ -1366,16 +1376,8 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
if (end > vma->vm_end)
end = vma->vm_end;
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
- return ret;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
- return ret;
-
- pmd = pmd_offset(pud, address);
- if (!pmd_present(*pmd))
+ pmd = mm_find_pmd(mm, address);
+ if (!pmd)
return ret;
mmun_start = address;