> -----Original Message----- > From: Hillf Danton [mailto:hillf.zj@xxxxxxxxxxxxxxx] > Sent: Monday, December 08, 2014 5:33 PM > To: Wang, Yalin > Cc: linux-kernel; linux-mm@xxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > Andrew Morton; Hillf Danton > Subject: Re: [PATCH] mm:add VM_BUG_ON() for page_mapcount() > > > > > This patch add VM_BUG_ON() for slab page, because _mapcount is an > > union with slab struct in struct page, avoid access _mapcount if this > > page is a slab page. > > Also remove the unneeded bracket. > > > > Signed-off-by: Yalin Wang <yalin.wang@xxxxxxxxxxxxxx> > > --- > > include/linux/mm.h | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/include/linux/mm.h b/include/linux/mm.h index > > 11b65cf..34124c4 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -373,7 +373,8 @@ static inline void reset_page_mapcount(struct page > > *page) > > > > static inline int page_mapcount(struct page *page) { > > - return atomic_read(&(page)->_mapcount) + 1; > > + VM_BUG_ON(PageSlab(page)); > > s/ VM_BUG_ON/ VM_BUG_ON_PAGE/ ? Yes, I will send again . ��.n������g��� �a��� �&ޖ)���)��h���&������梷���� �Ǟ�m������)������^�����������v���O��zf������