Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757793AbcLBAWw (ORCPT ); Thu, 1 Dec 2016 19:22:52 -0500 Received: from outbound-smtp04.blacknight.com ([81.17.249.35]:47432 "EHLO outbound-smtp04.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752680AbcLBAWu (ORCPT ); Thu, 1 Dec 2016 19:22:50 -0500 From: Mel Gorman To: Andrew Morton Cc: Christoph Lameter , Michal Hocko , Vlastimil Babka , Johannes Weiner , Jesper Dangaard Brouer , Linux-MM , Linux-Kernel , Mel Gorman Subject: [PATCH 1/2] mm, page_alloc: Keep pcp count and list contents in sync if struct page is corrupted Date: Fri, 2 Dec 2016 00:22:43 +0000 Message-Id: <20161202002244.18453-2-mgorman@techsingularity.net> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161202002244.18453-1-mgorman@techsingularity.net> References: <20161202002244.18453-1-mgorman@techsingularity.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1391 Lines: 43 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)); spin_unlock(&zone->lock); - return i; + return alloced; } #ifdef CONFIG_NUMA -- 2.10.2