Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932871AbbHKWUm (ORCPT ); Tue, 11 Aug 2015 18:20:42 -0400 Received: from blu004-omc1s13.hotmail.com ([65.55.116.24]:51155 "EHLO BLU004-OMC1S13.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753014AbbHKWUj (ORCPT ); Tue, 11 Aug 2015 18:20:39 -0400 X-TMN: [hUcbPbunOpTK+9Lp5SJvKoogplDZXydj] X-Originating-Email: [wanpeng.li@hotmail.com] Message-ID: Subject: Re: [PATCH] mm/hwpoison: fix panic due to split huge zero page To: Andrew Morton References: <20150811141404.ecb19c1a66c32abf60d6663c@linux-foundation.org> CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi From: Wanpeng Li Date: Wed, 12 Aug 2015 06:20:33 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 MIME-Version: 1.0 In-Reply-To: <20150811141404.ecb19c1a66c32abf60d6663c@linux-foundation.org> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 11 Aug 2015 22:20:38.0073 (UTC) FILETIME=[F341E290:01D0D483] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1112 Lines: 30 On 8/12/15 5:14 AM, Andrew Morton wrote: > On Tue, 11 Aug 2015 18:47:57 +0800 Wanpeng Li wrote: > >> ... >> >> Huge zero page is allocated if page fault w/o FAULT_FLAG_WRITE flag. >> The get_user_pages_fast() which called in madvise_hwpoison() will get >> huge zero page if the page is not allocated before. Huge zero page is >> a tranparent huge page, however, it is not an anonymous page. memory_failure >> will split the huge zero page and trigger BUG_ON(is_huge_zero_page(page)); >> After commit (98ed2b0: mm/memory-failure: give up error handling for >> non-tail-refcounted thp), memory_failure will not catch non anon thp >> from madvise_hwpoison path and this bug occur. > So I'm assuming this patch is needed for 4.2 but not in earlier > kernels. I think so. :-) Btw, how about my other hwpoison patches? Regards, Wanpeng Li > -- 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/