Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752626Ab3HVJsq (ORCPT ); Thu, 22 Aug 2013 05:48:46 -0400 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:37933 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752273Ab3HVJso (ORCPT ); Thu, 22 Aug 2013 05:48:44 -0400 From: Wanpeng Li To: Andrew Morton Cc: Andi Kleen , Fengguang Wu , Naoya Horiguchi , Tony Luck , gong.chen@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH 3/6] mm/hwpoison: fix num_poisoned_pages error statistics for thp Date: Thu, 22 Aug 2013 17:48:24 +0800 Message-Id: <1377164907-24801-3-git-send-email-liwanp@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1377164907-24801-1-git-send-email-liwanp@linux.vnet.ibm.com> References: <1377164907-24801-1-git-send-email-liwanp@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13082220-3568-0000-0000-0000041F2DA0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1468 Lines: 36 There is a race between hwpoison page and unpoison page, memory_failure set the page hwpoison and increase num_poisoned_pages without hold page lock, and one page count will be accounted against thp for num_poisoned_pages. However, unpoison can occur before memory_failure hold page lock and split transparent hugepage, unpoison will decrease num_poisoned_pages by 1 << compound_order since memory_failure has not yet split transparent hugepage with page lock held. That means we account one page for hwpoison and 1 << compound_order for unpoison. This patch fix it by decrease one account for num_poisoned_pages against no hugetlbfs pages case. Signed-off-by: Wanpeng Li --- mm/memory-failure.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5092e06..6bfd51e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1350,7 +1350,7 @@ int unpoison_memory(unsigned long pfn) return 0; } if (TestClearPageHWPoison(p)) - atomic_long_sub(nr_pages, &num_poisoned_pages); + atomic_long_dec(&num_poisoned_pages); pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn); return 0; } -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/