lkml.org 
[lkml]   [2005]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    SubjectRe: 2.6.15-rc4 panic in __nr_to_section() with CONFIG_SPARSEMEM
    From
    Date
    On Wed, 2005-12-07 at 15:22 -0800, Badari Pulavarty wrote:
    > BTW, the problem seems to be while dealing with shared memory areas
    > that are backed by largepages.

    I think this is likely not directly a sparsemem problem. It probably
    just shows symptoms earlier.

    See the attached patch. It attempts to detect and handle hugetlb pages
    in the smaps code. However, I think one of the root issues here is that
    bad_pmd() triggers for hugetlb pmds. I audited a few places where it is
    called, and at least a couple of them can't have hugepages handed into
    them, like fork().

    -- Dave



    ---

    proc-dups-dave/fs/proc/task_mmu.c | 22 ++++++++++++++++++++++
    1 files changed, 22 insertions(+)

    diff -puN fs/proc/task_mmu.c~task_mmu_fix fs/proc/task_mmu.c
    --- proc-dups/fs/proc/task_mmu.c~task_mmu_fix 2005-12-07 16:34:38.000000000 -0800
    +++ proc-dups-dave/fs/proc/task_mmu.c 2005-12-07 16:34:47.000000000 -0800
    @@ -245,6 +245,28 @@ static inline void smaps_pmd_range(struc
    pmd = pmd_offset(pud, addr);
    do {
    next = pmd_addr_end(addr, end);
    +
    + if (pmd_huge(*pmd)) {
    + struct page *page;
    +
    + page = follow_huge_pmd(vma->vm_mm, addr, pmd, 0);
    + if (!page)
    + continue;
    +
    + mss->resident += HPAGE_SIZE;
    + if (page_count(page) >= 2) {
    + if (pte_dirty(*(pte_t *)pmd))
    + mss->shared_dirty += HPAGE_SIZE;
    + else
    + mss->shared_clean += HPAGE_SIZE;
    + } else {
    + if (pte_dirty(*(pte_t *)pmd))
    + mss->private_dirty += HPAGE_SIZE;
    + else
    + mss->private_clean += HPAGE_SIZE;
    + }
    + continue;
    + }
    if (pmd_none_or_clear_bad(pmd))
    continue;
    smaps_pte_range(vma, pmd, addr, next, mss);
    _

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-12-08 01:50    [W:0.026 / U:0.136 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site