Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> > On Nov 29, 2018, at 4:44 AM, Yongkai Wu <nic.wuyk@xxxxxxxxx> 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 <nic_w@xxxxxxx> > Acked-by: Michal Hocko <mhocko@xxxxxxxx> > Acked-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > --- > 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 >
