From f488401076c5570130c018e573f450a9a6c43365 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Mon, 24 May 2010 14:32:10 -0700 Subject: mincore: break do_mincore() into logical pieces Split out functions to handle hugetlb ranges, pte ranges and unmapped ranges, to improve readability but also to prepare the file structure for nested page table walks. No semantic changes intended. Signed-off-by: Johannes Weiner Cc: Andrea Arcangeli Cc: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mincore.c | 171 +++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 97 insertions(+), 74 deletions(-) diff --git a/mm/mincore.c b/mm/mincore.c index 1f6574c5167b..a0c4c10bbab7 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -19,6 +19,42 @@ #include #include +static void mincore_hugetlb_page_range(struct vm_area_struct *vma, + unsigned long addr, unsigned long nr, + unsigned char *vec) +{ +#ifdef CONFIG_HUGETLB_PAGE + struct hstate *h; + int i; + + i = 0; + h = hstate_vma(vma); + while (1) { + unsigned char present; + pte_t *ptep; + /* + * Huge pages are always in RAM for now, but + * theoretically it needs to be checked. + */ + ptep = huge_pte_offset(current->mm, + addr & huge_page_mask(h)); + present = ptep && !huge_pte_none(huge_ptep_get(ptep)); + while (1) { + vec[i++] = present; + addr += PAGE_SIZE; + /* reach buffer limit */ + if (i == nr) + return; + /* check hugepage border */ + if (!(addr & ~huge_page_mask(h))) + break; + } + } +#else + BUG(); +#endif +} + /* * Later we can get more picky about what "in core" means precisely. * For now, simply check to see if the page is in the page cache, @@ -49,6 +85,64 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff) return present; } +static void mincore_unmapped_range(struct vm_area_struct *vma, + unsigned long addr, unsigned long nr, + unsigned char *vec) +{ + int i; + + if (vma->vm_file) { + pgoff_t pgoff; + + pgoff = linear_page_index(vma, addr); + for (i = 0; i < nr; i++, pgoff++) + vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff); + } else { + for (i = 0; i < nr; i++) + vec[i] = 0; + } +} + +static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd, + unsigned long addr, unsigned long nr, + unsigned char *vec) +{ + spinlock_t *ptl; + pte_t *ptep; + int i; + + ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); + for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) { + pte_t pte = *ptep; + pgoff_t pgoff; + + if (pte_none(pte)) + mincore_unmapped_range(vma, addr, 1, vec); + else if (pte_present(pte)) + vec[i] = 1; + else if (pte_file(pte)) { + pgoff = pte_to_pgoff(pte); + vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff); + } else { /* pte is a swap entry */ + swp_entry_t entry = pte_to_swp_entry(pte); + + if (is_migration_entry(entry)) { + /* migration entries are always uptodate */ + vec[i] = 1; + } else { +#ifdef CONFIG_SWAP + pgoff = entry.val; + vec[i] = mincore_page(&swapper_space, pgoff); +#else + WARN_ON(1); + vec[i] = 1; +#endif + } + } + } + pte_unmap_unlock(ptep - 1, ptl); +} + /* * Do a chunk of "sys_mincore()". We've already checked * all the arguments, we hold the mmap semaphore: we should @@ -59,11 +153,7 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v pgd_t *pgd; pud_t *pud; pmd_t *pmd; - pte_t *ptep; - spinlock_t *ptl; unsigned long nr; - int i; - pgoff_t pgoff; struct vm_area_struct *vma; vma = find_vma(current->mm, addr); @@ -72,35 +162,10 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v nr = min(pages, (vma->vm_end - addr) >> PAGE_SHIFT); -#ifdef CONFIG_HUGETLB_PAGE if (is_vm_hugetlb_page(vma)) { - struct hstate *h; - - i = 0; - h = hstate_vma(vma); - while (1) { - unsigned char present; - /* - * Huge pages are always in RAM for now, but - * theoretically it needs to be checked. - */ - ptep = huge_pte_offset(current->mm, - addr & huge_page_mask(h)); - present = ptep && !huge_pte_none(huge_ptep_get(ptep)); - while (1) { - vec[i++] = present; - addr += PAGE_SIZE; - /* reach buffer limit */ - if (i == nr) - return nr; - /* check hugepage border */ - if (!(addr & ~huge_page_mask(h))) - break; - } - } + mincore_hugetlb_page_range(vma, addr, nr, vec); return nr; } -#endif /* * Calculate how many pages there are left in the last level of the @@ -118,53 +183,11 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v if (pmd_none_or_clear_bad(pmd)) goto none_mapped; - ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); - for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) { - pte_t pte = *ptep; - - if (pte_none(pte)) { - if (vma->vm_file) { - pgoff = linear_page_index(vma, addr); - vec[i] = mincore_page(vma->vm_file->f_mapping, - pgoff); - } else - vec[i] = 0; - } else if (pte_present(pte)) - vec[i] = 1; - else if (pte_file(pte)) { - pgoff = pte_to_pgoff(pte); - vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff); - } else { /* pte is a swap entry */ - swp_entry_t entry = pte_to_swp_entry(pte); - - if (is_migration_entry(entry)) { - /* migration entries are always uptodate */ - vec[i] = 1; - } else { -#ifdef CONFIG_SWAP - pgoff = entry.val; - vec[i] = mincore_page(&swapper_space, pgoff); -#else - WARN_ON(1); - vec[i] = 1; -#endif - } - } - } - pte_unmap_unlock(ptep - 1, ptl); - + mincore_pte_range(vma, pmd, addr, nr, vec); return nr; none_mapped: - if (vma->vm_file) { - pgoff = linear_page_index(vma, addr); - for (i = 0; i < nr; i++, pgoff++) - vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff); - } else { - for (i = 0; i < nr; i++) - vec[i] = 0; - } - + mincore_unmapped_range(vma, addr, nr, vec); return nr; } -- cgit v1.2.3