From 6219049ae1ce32b89236646cccaec2a5fc6c4fd2 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Tue, 11 Dec 2012 16:00:37 -0800 Subject: 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 Cc: Andrea Arcangeli Cc: Michal Hocko Cc: Minchan Kim Cc: Ni zhan Chen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/rmap.c | 48 +++++++++++++++++++++++++----------------------- 1 file changed, 25 insertions(+), 23 deletions(-) (limited to 'mm/rmap.c') 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; -- cgit v1.2.3-55-g7522