On Tue 18-12-18 20:57:32, Qian Cai wrote: [...] > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 5411de93a363..f083f366ea90 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -985,9 +985,7 @@ extern int page_to_nid(const struct page *page); > #else > static inline int page_to_nid(const struct page *page) > { > - struct page *p = (struct page *)page; > - > - return (PF_POISONED_CHECK(p)->flags >> NODES_PGSHIFT) & NODES_MASK; > + return (page->flags >> NODES_PGSHIFT) & NODES_MASK; > } > #endif
I didn't get to think about a proper fix but this is clearly worng. If the page is still poisoned then flags are clearly bogus and the node you get is a garbage as well. Have you actually tested this patch? -- Michal Hocko SUSE Labs