lkml.org 
[lkml]   [2012]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH] hugetlb: avoid gratuitous BUG_ON in hugetlb_fault() -> hugetlb_cow()
    From
    On Mon, Apr 30, 2012 at 3:04 AM, Chris Metcalf <cmetcalf@tilera.com> wrote:
    > Commit 66aebce747eaf added code to avoid a race condition by
    > elevating the page refcount in hugetlb_fault() while calling
    > hugetlb_cow().  However, one code path in hugetlb_cow() includes
    > an assertion that the page count is 1, whereas it may now also
    > have the value 2 in this path.  Consensus is that this BUG_ON
    > has served its purpose, so rather than extending it to cover both
    > cases, we just remove it.
    >
    > Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
    > ---

    Acked-by: Hillf Danton <dhillf@gmail.com>

    >  mm/hugetlb.c |    1 -
    >  1 files changed, 0 insertions(+), 1 deletions(-)
    >
    > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
    > index cd65cb1..baaad5d 100644
    > --- a/mm/hugetlb.c
    > +++ b/mm/hugetlb.c
    > @@ -2498,7 +2498,6 @@ retry_avoidcopy:
    >                if (outside_reserve) {
    >                        BUG_ON(huge_pte_none(pte));
    >                        if (unmap_ref_private(mm, vma, old_page, address)) {
    > -                               BUG_ON(page_count(old_page) != 1);
    >                                BUG_ON(huge_pte_none(pte));
    >                                spin_lock(&mm->page_table_lock);
    >                                ptep = huge_pte_offset(mm, address & huge_page_mask(h));
    > --
    > 1.6.5.2
    >
    --
    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: 2012-05-01 16:21    [W:0.027 / U:118.236 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site