From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f175.google.com (mail-ig0-f175.google.com [209.85.213.175]) by kanga.kvack.org (Postfix) with ESMTP id 29EE26B0253 for ; Tue, 11 Aug 2015 18:20:40 -0400 (EDT) Received: by igbij6 with SMTP id ij6so100564398igb.1 for ; Tue, 11 Aug 2015 15:20:40 -0700 (PDT) Received: from BLU004-OMC1S13.hotmail.com (blu004-omc1s13.hotmail.com. [65.55.116.24]) by mx.google.com with ESMTPS id t91si2493581ioi.103.2015.08.11.15.20.39 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 11 Aug 2015 15:20:39 -0700 (PDT) Message-ID: Subject: Re: [PATCH] mm/hwpoison: fix panic due to split huge zero page References: <20150811141404.ecb19c1a66c32abf60d6663c@linux-foundation.org> From: Wanpeng Li Date: Wed, 12 Aug 2015 06:20:33 +0800 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 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi 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, 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