From patchwork Tue Jul 3 06:01:34 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yasuaki Ishimatsu X-Patchwork-Id: 168711 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 3E2862C07A0 for ; Tue, 3 Jul 2012 16:02:44 +1000 (EST) Received: from fgwmail5.fujitsu.co.jp (fgwmail5.fujitsu.co.jp [192.51.44.35]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 7CDFA2C00F8 for ; Tue, 3 Jul 2012 16:01:49 +1000 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 6A0953EE0C3 for ; Tue, 3 Jul 2012 15:01:47 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 501B445DE52 for ; Tue, 3 Jul 2012 15:01:47 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 3852F45DE50 for ; Tue, 3 Jul 2012 15:01:47 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1A74E1DB8042 for ; Tue, 3 Jul 2012 15:01:47 +0900 (JST) Received: from g01jpexchyt08.g01.fujitsu.local (g01jpexchyt08.g01.fujitsu.local [10.128.194.47]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id C346D1DB803B for ; Tue, 3 Jul 2012 15:01:46 +0900 (JST) Received: from [127.0.0.1] (10.124.101.33) by g01jpexchyt08.g01.fujitsu.local (10.128.194.47) with Microsoft SMTP Server id 14.2.309.2; Tue, 3 Jul 2012 15:01:43 +0900 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <4FF28ABE.4010200@jp.fujitsu.com> Date: Tue, 3 Jul 2012 15:01:34 +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 v2 8/13] memory-hotplug : check page type in get_page_bootmem References: <4FF287C3.4030901@jp.fujitsu.com> In-Reply-To: <4FF287C3.4030901@jp.fujitsu.com> Cc: len.brown@intel.com, paulus@samba.org, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com, rientjes@google.com, cl@linux.com, akpm@linux-foundation.org, liuj97@gmail.com X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 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: David Rientjes CC: Jiang Liu CC: Len Brown CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Christoph Lameter Cc: Minchan Kim CC: Andrew Morton CC: KOSAKI Motohiro Signed-off-by: Yasuaki Ishimatsu --- mm/memory_hotplug.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) Index: linux-3.5-rc4/mm/memory_hotplug.c =================================================================== --- linux-3.5-rc4.orig/mm/memory_hotplug.c 2012-07-03 14:22:10.170116406 +0900 +++ linux-3.5-rc4/mm/memory_hotplug.c 2012-07-03 14:22:12.299089413 +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