From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 6E1706B0038 for ; Thu, 1 Dec 2016 22:48:14 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id x23so139978923pgx.6 for ; Thu, 01 Dec 2016 19:48:14 -0800 (PST) Received: from out4433.biz.mail.alibaba.com (out4433.biz.mail.alibaba.com. [47.88.44.33]) by mx.google.com with ESMTP id s2si3101028pgd.57.2016.12.01.19.48.11 for ; Thu, 01 Dec 2016 19:48:13 -0800 (PST) Reply-To: "Hillf Danton" From: "Hillf Danton" 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 Content-Language: zh-cn Sender: owner-linux-mm@kvack.org List-ID: To: 'Mel Gorman' , 'Andrew Morton' Cc: 'Christoph Lameter' , 'Michal Hocko' , 'Vlastimil Babka' , 'Johannes Weiner' , 'Jesper Dangaard Brouer' , 'Linux-MM' , 'Linux-Kernel' 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org