| Message ID | 1543491843-23438-1-git-send-email-nic_w@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hugetlbfs: Call VM_BUG_ON_PAGE earlier in free_huge_page | expand |
Reviewed-by: William Kucharski <william.kucharski@oracle.com> > On Nov 29, 2018, at 4:44 AM, Yongkai Wu <nic.wuyk@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 <nic_w@163.com> > Acked-by: Michal Hocko <mhocko@suse.com> > Acked-by: Mike Kravetz <mike.kravetz@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 >
On 11/29/18 5:51 AM, William Kucharski wrote: > Reviewed-by: William Kucharski <william.kucharski@oracle.com> > >> On Nov 29, 2018, at 4:44 AM, Yongkai Wu <nic.wuyk@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 <nic_w@163.com> >> Acked-by: Michal Hocko <mhocko@suse.com> >> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Thank you for fixing the formatting and commit message. Adding Andrew on so he can add to his tree as appropriatre. Also Cc'ing Michal. >> --- >> 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 >> >
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);