From 45789e4a8f261e08a1f04341589d968d42c4bda9 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Fri, 9 Nov 2012 14:03:58 +1100 Subject: [PATCH] mm: introduce mm_find_pmd() Several place need to find the pmd by(mm_struct, address), so introduce a function to simplify it. Signed-off-by: Bob Liu Cc: Andrea Arcangeli Cc: Michal Hocko Cc: Minchan Kim Cc: Ni zhan Chen Signed-off-by: Andrew Morton --- mm/huge_memory.c | 55 +++++++++--------------------------------------- mm/internal.h | 5 +++++ mm/ksm.c | 14 ++---------- mm/migrate.c | 14 ++---------- mm/rmap.c | 46 ++++++++++++++++++++++------------------ 5 files changed, 44 insertions(+), 90 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 36bed8342bd6..16ee6771c649 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1294,22 +1294,14 @@ pmd_t *page_check_address_pmd(struct page *page, unsigned long address, enum page_check_address_pmd_flag flag) { - pgd_t *pgd; - pud_t *pud; pmd_t *pmd, *ret = NULL; if (address & ~HPAGE_PMD_MASK) goto out; - pgd = pgd_offset(mm, address); - if (!pgd_present(*pgd)) - goto out; - - pud = pud_offset(pgd, address); - if (!pud_present(*pud)) + pmd = mm_find_pmd(mm, address); + if (!pmd) goto out; - - pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) goto out; if (pmd_page(*pmd) != page) @@ -2054,8 +2046,6 @@ static void collapse_huge_page(struct mm_struct *mm, struct vm_area_struct *vma, int node) { - pgd_t *pgd; - pud_t *pud; pmd_t *pmd, _pmd; pte_t *pte; pgtable_t pgtable; @@ -2101,17 +2091,10 @@ static void collapse_huge_page(struct mm_struct *mm, goto out; VM_BUG_ON(vma->vm_flags & VM_NO_THP); - pgd = pgd_offset(mm, address); - if (!pgd_present(*pgd)) - goto out; - - pud = pud_offset(pgd, address); - if (!pud_present(*pud)) + pmd = mm_find_pmd(mm, address); + if (!pmd) goto out; - - pmd = pmd_offset(pud, address); - /* pmd can't go away or become huge under us */ - if (!pmd_present(*pmd) || pmd_trans_huge(*pmd)) + if (pmd_trans_huge(*pmd)) goto out; anon_vma_lock(vma->anon_vma); @@ -2194,8 +2177,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, unsigned long address, struct page **hpage) { - pgd_t *pgd; - pud_t *pud; pmd_t *pmd; pte_t *pte, *_pte; int ret = 0, referenced = 0, none = 0; @@ -2206,16 +2187,10 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, VM_BUG_ON(address & ~HPAGE_PMD_MASK); - pgd = pgd_offset(mm, address); - if (!pgd_present(*pgd)) - goto out; - - pud = pud_offset(pgd, address); - if (!pud_present(*pud)) + pmd = mm_find_pmd(mm, address); + if (!pmd) goto out; - - pmd = pmd_offset(pud, address); - if (!pmd_present(*pmd) || pmd_trans_huge(*pmd)) + if (pmd_trans_huge(*pmd)) goto out; pte = pte_offset_map_lock(mm, pmd, address, &ptl); @@ -2507,22 +2482,12 @@ void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd) static void split_huge_page_address(struct mm_struct *mm, unsigned long address) { - pgd_t *pgd; - pud_t *pud; pmd_t *pmd; VM_BUG_ON(!(address & ~HPAGE_PMD_MASK)); - pgd = pgd_offset(mm, address); - if (!pgd_present(*pgd)) - return; - - pud = pud_offset(pgd, address); - if (!pud_present(*pud)) - return; - - pmd = pmd_offset(pud, address); - if (!pmd_present(*pmd)) + pmd = mm_find_pmd(mm, address); + if (!pmd) return; /* * Caller holds the mmap_sem write mode, so a huge pmd cannot diff --git a/mm/internal.h b/mm/internal.h index a4fa284f6bc2..52d1fa957194 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -91,6 +91,11 @@ extern unsigned long highest_memmap_pfn; extern int isolate_lru_page(struct page *page); extern void putback_lru_page(struct page *page); +/* + * in mm/rmap.c: + */ +extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); + /* * in mm/page_alloc.c */ diff --git a/mm/ksm.c b/mm/ksm.c index ae539f0b8aa1..31ae5ea1eac0 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -778,8 +778,6 @@ static int replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage, pte_t orig_pte) { struct mm_struct *mm = vma->vm_mm; - pgd_t *pgd; - pud_t *pud; pmd_t *pmd; pte_t *ptep; spinlock_t *ptl; @@ -792,18 +790,10 @@ static int replace_page(struct vm_area_struct *vma, struct page *page, if (addr == -EFAULT) goto out; - pgd = pgd_offset(mm, addr); - if (!pgd_present(*pgd)) + pmd = mm_find_pmd(mm, addr); + if (!pmd) goto out; - - pud = pud_offset(pgd, addr); - if (!pud_present(*pud)) - goto out; - - pmd = pmd_offset(pud, addr); BUG_ON(pmd_trans_huge(*pmd)); - if (!pmd_present(*pmd)) - goto out; mmun_start = addr; mmun_end = addr + PAGE_SIZE; diff --git a/mm/migrate.c b/mm/migrate.c index 72d10560caf6..0c5ec37bd2e7 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -91,8 +91,6 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, { struct mm_struct *mm = vma->vm_mm; swp_entry_t entry; - pgd_t *pgd; - pud_t *pud; pmd_t *pmd; pte_t *ptep, pte; spinlock_t *ptl; @@ -103,19 +101,11 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, goto out; ptl = &mm->page_table_lock; } else { - pgd = pgd_offset(mm, addr); - if (!pgd_present(*pgd)) + pmd = mm_find_pmd(mm, addr); + if (!pmd) goto out; - - pud = pud_offset(pgd, addr); - if (!pud_present(*pud)) - goto out; - - pmd = pmd_offset(pud, addr); if (pmd_trans_huge(*pmd)) goto out; - if (!pmd_present(*pmd)) - goto out; ptep = pte_offset_map(pmd, addr); diff --git a/mm/rmap.c b/mm/rmap.c index 2ee1ef0f317b..62a4a8cb8879 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; @@ -1366,16 +1378,8 @@ 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; -- 2.39.5