From patchwork Wed Oct 31 11:23:09 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 1678651 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 36B003FDDA for ; Wed, 31 Oct 2012 11:49:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935419Ab2JaLsc (ORCPT ); Wed, 31 Oct 2012 07:48:32 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:55903 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S932760Ab2JaLsa (ORCPT ); Wed, 31 Oct 2012 07:48:30 -0400 X-IronPort-AV: E=Sophos;i="4.80,687,1344182400"; d="scan'208";a="6108904" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 31 Oct 2012 19:46:47 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q9VBHSUb026747; Wed, 31 Oct 2012 19:17:29 +0800 Received: from ghost.fnst.cn.fujitsu.com ([10.167.225.226]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012103119164473-879576 ; Wed, 31 Oct 2012 19:16:44 +0800 From: Wen Congyang To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Cc: Jiang Liu , Len Brown , Andrew Morton , KOSAKI Motohiro , Yasuaki Ishimatsu , rjw@sisk.pl, Lai Jiangshan , Wen Congyang , David Rientjes , Benjamin Herrenschmidt , Paul Mackerras , Christoph Lameter , Minchan Kim , Dave Hansen , Mel Gorman Subject: [Patch v4 3/8] memory-hotplug: fix NR_FREE_PAGES mismatch Date: Wed, 31 Oct 2012 19:23:09 +0800 Message-Id: <1351682594-17347-4-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 1.8.0 In-Reply-To: <1351682594-17347-1-git-send-email-wency@cn.fujitsu.com> References: <1351682594-17347-1-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/10/31 19:16:44, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/10/31 19:16:54, Serialize complete at 2012/10/31 19:16:54 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org NR_FREE_PAGES will be wrong after offlining pages. We add/dec NR_FREE_PAGES like this now: 1. move all pages in buddy system to MIGRATE_ISOLATE, and dec NR_FREE_PAGES 2. don't add NR_FREE_PAGES when it is freed and the migratetype is MIGRATE_ISOLATE 3. dec NR_FREE_PAGES when offlining isolated pages. 4. add NR_FREE_PAGES when undoing isolate pages. When we come to step 3, all pages are in MIGRATE_ISOLATE list, and NR_FREE_PAGES are right. When we come to step4, all pages are not in buddy system, so we don't change NR_FREE_PAGES in this step, but we change NR_FREE_PAGES in step3. So NR_FREE_PAGES is wrong after offlining pages. So there is no need to change NR_FREE_PAGES in step3. This patch also fixs a problem in step2: if the migratetype is MIGRATE_ISOLATE, we should not add NR_FRR_PAGES when we remove pages from pcppages. Signed-off-by: Wen Congyang Cc: David Rientjes Cc: Jiang Liu Cc: Len Brown Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Christoph Lameter Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Yasuaki Ishimatsu Cc: Dave Hansen Cc: Mel Gorman Signed-off-by: Andrew Morton --- mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5b74de6..a7cd2d1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -667,11 +667,13 @@ static void free_pcppages_bulk(struct zone *zone, int count, /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ __free_one_page(page, zone, 0, mt); trace_mm_page_pcpu_drain(page, 0, mt); - if (is_migrate_cma(mt)) - __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1); + if (likely(mt != MIGRATE_ISOLATE)) { + __mod_zone_page_state(zone, NR_FREE_PAGES, 1); + if (is_migrate_cma(mt)) + __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1); + } } while (--to_free && --batch_free && !list_empty(list)); } - __mod_zone_page_state(zone, NR_FREE_PAGES, count); spin_unlock(&zone->lock); } @@ -5987,8 +5989,6 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) list_del(&page->lru); rmv_page_order(page); zone->free_area[order].nr_free--; - __mod_zone_page_state(zone, NR_FREE_PAGES, - - (1UL << order)); for (i = 0; i < (1 << order); i++) SetPageReserved((page+i)); pfn += (1 << order);