From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id C85106B0044 for ; Fri, 24 Aug 2012 04:06:30 -0400 (EDT) Date: Fri, 24 Aug 2012 10:06:26 +0200 From: Michal Hocko 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: Sender: owner-linux-mm@kvack.org List-ID: To: Li Haifeng Cc: Gavin Shan , Andrew Morton , Mel Gorman , Minchan Kim , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org