Messages in this thread Patch in this message | | | Date | Mon, 07 Dec 2009 16:59:25 +0900 | From | Naoya Horiguchi <> | Subject | [PATCH 2/2] mm hugetlb: add hugepage support to pagemap |
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This patch enables to extract pfn of the hugepage from /proc/pid/pagemap in architecture independent manner.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wu Fengguang <fengguang.wu@intel.com> --- fs/proc/task_mmu.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/linux/mm.h | 3 +++ mm/pagewalk.c | 18 ++++++++++++++++-- 3 files changed, 62 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2a1bef9..5d8e86b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -650,6 +650,48 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, return err; } +static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset) +{ + u64 pme = 0; + if (pte_present(pte)) + pme = PM_PFRAME(pte_pfn(pte) + offset) + | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; + return pme; +} + +static int pagemap_hugetlb_range(pte_t *pte, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct vm_area_struct *vma; + struct pagemapread *pm = walk->private; + struct hstate *hs = NULL; + int err = 0; + + vma = find_vma(walk->mm, addr); + hs = hstate_vma(vma); + for (; addr != end; addr += PAGE_SIZE) { + u64 pfn = PM_NOT_PRESENT; + + if (vma && (addr >= vma->vm_end)) { + vma = find_vma(walk->mm, addr); + hs = hstate_vma(vma); + } + + if (vma && (vma->vm_start <= addr) && is_vm_hugetlb_page(vma)) { + /* calculate pfn of the "raw" page in the hugepage. */ + int offset = (addr & ~huge_page_mask(hs)) >> PAGE_SHIFT; + pfn = huge_pte_to_pagemap_entry(*pte, offset); + } + err = add_to_pagemap(addr, pfn, pm); + if (err) + return err; + } + + cond_resched(); + + return err; +} + /* * /proc/pid/pagemap - an array mapping virtual pages to pfns * @@ -742,6 +784,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, pagemap_walk.pmd_entry = pagemap_pte_range; pagemap_walk.pte_hole = pagemap_pte_hole; + pagemap_walk.hugetlb_entry = pagemap_hugetlb_range; pagemap_walk.mm = mm; pagemap_walk.private = ± diff --git a/include/linux/mm.h b/include/linux/mm.h index 4d33403..14835f0 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -758,6 +758,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlb, * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry * @pte_entry: if set, called for each non-empty PTE (4th-level) entry * @pte_hole: if set, called for each hole at all levels + * @hugetlb_entry: if set, called for each hugetlb entry * * (see walk_page_range for more details) */ @@ -767,6 +768,8 @@ struct mm_walk { int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *); int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *); int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *); + int (*hugetlb_entry)(pte_t *, unsigned long, unsigned long, + struct mm_walk *); struct mm_struct *mm; void *private; }; diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 3d88824..2d27a23 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -106,9 +106,11 @@ int walk_page_range(unsigned long addr, unsigned long end, struct mm_walk *walk) { pgd_t *pgd; + pte_t *pte; unsigned long next; int err = 0; struct vm_area_struct *vma; + struct hstate *hs; if (addr >= end) return err; @@ -120,11 +122,23 @@ int walk_page_range(unsigned long addr, unsigned long end, do { next = pgd_addr_end(addr, end); - /* skip hugetlb vma to avoid hugepage PMD being cleared - * in pmd_none_or_clear_bad(). */ + /* + * handle hugetlb vma individually because pagetable walk for + * the hugetlb page is dependent on the architecture and + * we can't handled it in the same manner as non-huge pages. + */ vma = find_vma(walk->mm, addr); if (is_vm_hugetlb_page(vma)) { next = (vma->vm_end < next) ? vma->vm_end : next; + hs = hstate_vma(vma); + pte = huge_pte_offset(walk->mm, + addr & huge_page_mask(hs)); + if (pte && !huge_pte_none(huge_ptep_get(pte)) + && walk->hugetlb_entry) + err = walk->hugetlb_entry(pte, addr, + next, walk); + if (err) + break; continue; } -- 1.6.0.6
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