Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755137AbcCNHcJ (ORCPT ); Mon, 14 Mar 2016 03:32:09 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34004 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755042AbcCNHbx (ORCPT ); Mon, 14 Mar 2016 03:31:53 -0400 From: js1304@gmail.com X-Google-Original-From: iamjoonsoo.kim@lge.com To: Andrew Morton Cc: Rik van Riel , Johannes Weiner , Mel Gorman , Laura Abbott , Minchan Kim , Marek Szyprowski , Michal Nazarewicz , "Aneesh Kumar K.V" , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Joonsoo Kim Subject: [PATCH 1/6] mm/page_alloc: fix same zone check in __pageblock_pfn_to_page() Date: Mon, 14 Mar 2016 16:31:32 +0900 Message-Id: <1457940697-2278-2-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1457940697-2278-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1457940697-2278-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 998 Lines: 34 From: Joonsoo Kim There is a system that node's pfn are overlapped like as following. -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to care this overlapping when iterating pfn range. In __pageblock_pfn_to_page(), there is a check for this but it's not sufficient. This check cannot distinguish the case that zone id is the same but node id is different. This patch fixes it. Signed-off-by: Joonsoo Kim --- mm/page_alloc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8120f07..93293b4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1173,8 +1173,7 @@ struct page *__pageblock_pfn_to_page(unsigned long start_pfn, end_page = pfn_to_page(end_pfn); - /* This gives a shorter code than deriving page_zone(end_page) */ - if (page_zone_id(start_page) != page_zone_id(end_page)) + if (zone != page_zone(end_page)) return NULL; return start_page; -- 1.9.1