Messages in this thread | | | From | "Hillf Danton" <> | Subject | Re: [PATCH V3] mm:add VM_BUG_ON_PAGE() for page_mapcount() | Date | Tue, 09 Dec 2014 11:18:32 +0800 |
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> > This patch add VM_BUG_ON_PAGE() 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@sonymobile.com> > --- Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
> 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 b464611..a117527 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -449,7 +449,8 @@ static inline void page_mapcount_reset(struct page *page) > > static inline int page_mapcount(struct page *page) > { > - return atomic_read(&(page)->_mapcount) + 1; > + VM_BUG_ON_PAGE(PageSlab(page), page); > + return atomic_read(&page->_mapcount) + 1; > } > > static inline int page_count(struct page *page) > -- > 2.1.3
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