From patchwork Wed Jun 27 05:53:17 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yasuaki Ishimatsu X-Patchwork-Id: 167552 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 5ADD31011A4 for ; Wed, 27 Jun 2012 17:14:37 +1000 (EST) Received: from fgwmail6.fujitsu.co.jp (fgwmail6.fujitsu.co.jp [192.51.44.36]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 637AAB6FA8 for ; Wed, 27 Jun 2012 15:53:35 +1000 (EST) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 813AD3EE0C3 for ; Wed, 27 Jun 2012 14:53:33 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 687B945DE50 for ; Wed, 27 Jun 2012 14:53:33 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 441EE45DD78 for ; Wed, 27 Jun 2012 14:53:33 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 35759E18004 for ; Wed, 27 Jun 2012 14:53:33 +0900 (JST) Received: from g01jpexchkw07.g01.fujitsu.local (g01jpexchkw07.g01.fujitsu.local [10.0.194.46]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id E72371DB8038 for ; Wed, 27 Jun 2012 14:53:32 +0900 (JST) Received: from [127.0.0.1] (10.124.101.33) by g01jpexchkw07.g01.fujitsu.local (10.0.194.46) with Microsoft SMTP Server id 14.2.247.3; Wed, 27 Jun 2012 14:53:32 +0900 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <4FEA9FCD.6020405@jp.fujitsu.com> Date: Wed, 27 Jun 2012 14:53:17 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: , , , Subject: [RFC PATCH 7/12] memory-hotplug : check page type in get_page_bootmem References: <4FEA9C88.1070800@jp.fujitsu.com> In-Reply-To: <4FEA9C88.1070800@jp.fujitsu.com> X-Mailman-Approved-At: Wed, 27 Jun 2012 17:06:19 +1000 Cc: len.brown@intel.com, wency@cn.fujitsu.com, paulus@samba.org, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com, cl@linux.com, akpm@linux-foundation.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15rc1 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" There is a possibility that get_page_bootmem() is called to the same page many times. So when get_page_bootmem is called to the same page, the function only increments page->_count. CC: Len Brown CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro CC: Wen Congyang Signed-off-by: Yasuaki Ishimatsu Index: linux-3.5-rc4/mm/memory_hotplug.c =================================================================== --- linux-3.5-rc4.orig/mm/memory_hotplug.c 2012-06-26 13:56:34.371988312 +0900 +++ linux-3.5-rc4/mm/memory_hotplug.c 2012-06-26 14:03:37.564697621 +0900 @@ -95,10 +95,17 @@ static void release_memory_resource(stru static void get_page_bootmem(unsigned long info, struct page *page, unsigned long type) { - page->lru.next = (struct list_head *) type; - SetPagePrivate(page); - set_page_private(page, info); - atomic_inc(&page->_count); + unsigned long page_type; + + page_type = (unsigned long) page->lru.next; + if (type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || + type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){ + page->lru.next = (struct list_head *) type; + SetPagePrivate(page); + set_page_private(page, info); + atomic_inc(&page->_count); + } else + atomic_inc(&page->_count); } /* reference to __meminit __free_pages_bootmem is valid