Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756633AbcLBDyq (ORCPT ); Thu, 1 Dec 2016 22:54:46 -0500 Received: from out0-141.mail.aliyun.com ([140.205.0.141]:60787 "EHLO out0-141.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751678AbcLBDye (ORCPT ); Thu, 1 Dec 2016 22:54:34 -0500 X-Greylist: delayed 357 seconds by postgrey-1.27 at vger.kernel.org; Thu, 01 Dec 2016 22:54:33 EST X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e02c03293;MF=hillf.zj@alibaba-inc.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---.7FIjT2-_1480650473; Reply-To: "Hillf Danton" From: "Hillf Danton" To: "'Mel Gorman'" , "'Andrew Morton'" Cc: "'Christoph Lameter'" , "'Michal Hocko'" , "'Vlastimil Babka'" , "'Johannes Weiner'" , "'Jesper Dangaard Brouer'" , "'Linux-MM'" , "'Linux-Kernel'" References: <20161202002244.18453-1-mgorman@techsingularity.net> <20161202002244.18453-2-mgorman@techsingularity.net> In-Reply-To: <20161202002244.18453-2-mgorman@techsingularity.net> Subject: Re: [PATCH 1/2] mm, page_alloc: Keep pcp count and list contents in sync if struct page is corrupted Date: Fri, 02 Dec 2016 11:47:53 +0800 Message-ID: <01d601d24c4e$dca6e190$95f4a4b0$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQIHR4g+bvnVwkChnMB02ZSKZ5j4cAFySElFoH57BjA= Content-Language: zh-cn Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1559 Lines: 47 On Friday, December 02, 2016 8:23 AM Mel Gorman wrote: > Vlastimil Babka pointed out that commit 479f854a207c ("mm, page_alloc: > defer debugging checks of pages allocated from the PCP") will allow the > per-cpu list counter to be out of sync with the per-cpu list contents > if a struct page is corrupted. This patch keeps the accounting in sync. > > Fixes: 479f854a207c ("mm, page_alloc: defer debugging checks of pages allocated from the PCP") > Signed-off-by: Mel Gorman > cc: stable@vger.kernel.org [4.7+] > --- > mm/page_alloc.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 6de9440e3ae2..777ed59570df 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2192,7 +2192,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, > unsigned long count, struct list_head *list, > int migratetype, bool cold) > { > - int i; > + int i, alloced = 0; > > spin_lock(&zone->lock); > for (i = 0; i < count; ++i) { > @@ -2217,13 +2217,14 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, > else > list_add_tail(&page->lru, list); > list = &page->lru; > + alloced++; > if (is_migrate_cma(get_pcppage_migratetype(page))) > __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, > -(1 << order)); > } > __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); Now i is a pure index, yes? > spin_unlock(&zone->lock); > - return i; > + return alloced; > } > > #ifdef CONFIG_NUMA > -- > 2.10.2