Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755127Ab2HXIGh (ORCPT ); Fri, 24 Aug 2012 04:06:37 -0400 Received: from cantor2.suse.de ([195.135.220.15]:50251 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753697Ab2HXIG3 (ORCPT ); Fri, 24 Aug 2012 04:06:29 -0400 Date: Fri, 24 Aug 2012 10:06:26 +0200 From: Michal Hocko To: Li Haifeng Cc: Gavin Shan , Andrew Morton , Mel Gorman , Minchan Kim , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: Fixup the page of buddy_higher address's calculation Message-ID: <20120824080626.GC29282@dhcp22.suse.cz> References: <20120823095022.GB10685@dhcp22.suse.cz> <20120823135839.GB19968@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1830 Lines: 47 On Fri 24-08-12 10:08:20, Li Haifeng wrote: [...] > Subject: [PATCH] Fix the page address of higher page's buddy calculation > > Calculate the page address of higher page's buddy should be based > higher_page with the offset between index of higher page and > index of higher page's buddy. Sorry for insisting but could you add an information about when this has been introduced (I have mentioned the commit in the other email) and the effect of the bug so that we can consider whether this is worth backporting to stable trees. > Signed-off-by: Haifeng Li > Signed-off-by: Gavin Shan Other than that Reviewed-by: Michal Hocko > --- > mm/page_alloc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cdef1d4..642cd62 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -536,7 +536,7 @@ static inline void __free_one_page(struct page *page, > combined_idx = buddy_idx & page_idx; > higher_page = page + (combined_idx - page_idx); > buddy_idx = __find_buddy_index(combined_idx, order + 1); > - higher_buddy = page + (buddy_idx - combined_idx); > + higher_buddy = higher_page + (buddy_idx - combined_idx); > if (page_is_buddy(higher_page, higher_buddy, order + 1)) { > list_add_tail(&page->lru, > &zone->free_area[order].free_list[migratetype]); > -- > 1.7.5.4 -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/