From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758332Ab2IEJpB (ORCPT ); Wed, 5 Sep 2012 05:45:01 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:47222 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751493Ab2IEJoz (ORCPT ); Wed, 5 Sep 2012 05:44:55 -0400 X-IronPort-AV: E=Sophos;i="4.80,373,1344182400"; d="scan'208";a="5789227" From: wency@cn.fujitsu.com To: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@vger.kernel.org Cc: rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, Wen Congyang Subject: [RFC v9 PATCH 13/21] memory-hotplug: check page type in get_page_bootmem Date: Wed, 5 Sep 2012 17:25:47 +0800 Message-Id: <1346837155-534-14-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1346837155-534-1-git-send-email-wency@cn.fujitsu.com> References: <1346837155-534-1-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/09/05 17:20:02, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/09/05 17:20:04, Serialize complete at 2012/09/05 17:20:04 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yasuaki Ishimatsu The function get_page_bootmem() may be called more than one time to the same page. There is no need to set page's type, private if the function is not the first time called to the page. Note: the patch is just optimization and does not fix any problem. 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 CC: Wen Congyang Signed-off-by: Yasuaki Ishimatsu --- mm/memory_hotplug.c | 15 +++++++++++---- 1 files changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index d736df3..26a5012 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -95,10 +95,17 @@ static void release_memory_resource(struct resource *res) 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 (page_type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || + page_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 -- 1.7.1