Reviewed-by: William Kucharski <william.kuchar...@oracle.com>
> On Nov 29, 2018, at 4:44 AM, Yongkai Wu <nic.w...@gmail.com> wrote:
>
> A stack trace was triggered by VM_BUG_ON_PAGE(page_mapcount(page),
> page) in free_huge_page(). Unfortunately, the page->mapping field
> was set to NULL before this test. This made it more difficult to
> determine the root cause of the problem.
>
> Move the VM_BUG_ON_PAGE tests earlier in the function so that if
> they do trigger more information is present in the page struct.
>
> Signed-off-by: Yongkai Wu <ni...@163.com>
> Acked-by: Michal Hocko <mho...@suse.com>
> Acked-by: Mike Kravetz <mike.krav...@oracle.com>
> ---
> mm/hugetlb.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 7f2a28a..14ef274 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1248,10 +1248,11 @@ void free_huge_page(struct page *page)
> (struct hugepage_subpool *)page_private(page);
> bool restore_reserve;
>
> - set_page_private(page, 0);
> - page->mapping = NULL;
> VM_BUG_ON_PAGE(page_count(page), page);
> VM_BUG_ON_PAGE(page_mapcount(page), page);
> +
> + set_page_private(page, 0);
> + page->mapping = NULL;
> restore_reserve = PagePrivate(page);
> ClearPagePrivate(page);
>
> --
> 1.8.3.1
>
