diff options
author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2009-12-14 18:00:01 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-15 08:53:24 -0800 |
commit | 5dc37642cbce34619e4588a9f0bdad1d2f870956 (patch) | |
tree | 00165a3a0b3d768abaf83cf44642f09398b989cc /fs/proc | |
parent | d33b9f45bd24a6391bc05e2b5a13c1b5787ca9c2 (diff) |
mm hugetlb: add hugepage support to pagemap
This patch enables extraction of the pfn of a hugepage from
/proc/pid/pagemap in an architecture independent manner.
Details
-------
My test program (leak_pagemap) works as follows:
- creat() and mmap() a file on hugetlbfs (file size is 200MB == 100 hugepages,)
- read()/write() something on it,
- call page-types with option -p,
- munmap() and unlink() the file on hugetlbfs
Without my patches
------------------
$ ./leak_pagemap
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000000 1 0 __________________________________
0x0000000000000804 1 0 __R________M______________________ referenced,mmap
0x000000000000086c 81 0 __RU_lA____M______________________ referenced,uptodate,lru,active,mmap
0x0000000000005808 5 0 ___U_______Ma_b___________________ uptodate,mmap,anonymous,swapbacked
0x0000000000005868 12 0 ___U_lA____Ma_b___________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c 1 0 __RU_lA____Ma_b___________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
total 101 0
The output of page-types don't show any hugepage.
With my patches
---------------
$ ./leak_pagemap
flags page-count MB symbolic-flags long-symbolic-flags
0x0000000000000000 1 0 __________________________________
0x0000000000030000 51100 199 ________________TG________________ compound_tail,huge
0x0000000000028018 100 0 ___UD__________H_G________________ uptodate,dirty,compound_head,huge
0x0000000000000804 1 0 __R________M______________________ referenced,mmap
0x000000000000080c 1 0 __RU_______M______________________ referenced,uptodate,mmap
0x000000000000086c 80 0 __RU_lA____M______________________ referenced,uptodate,lru,active,mmap
0x0000000000005808 4 0 ___U_______Ma_b___________________ uptodate,mmap,anonymous,swapbacked
0x0000000000005868 12 0 ___U_lA____Ma_b___________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c 1 0 __RU_lA____Ma_b___________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
total 51300 200
The output of page-types shows 51200 pages contributing to hugepages,
containing 100 head pages and 51100 tail pages as expected.
[akpm@linux-foundation.org: build fix]
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>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
-rw-r--r-- | fs/proc/task_mmu.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2a1bef9203c6..47c03f4336b8 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -650,6 +650,50 @@ 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); + if (vma) + 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); + if (vma) + 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 +786,7 @@ 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 = ± |