From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f52.google.com (mail-pb0-f52.google.com [209.85.160.52]) by kanga.kvack.org (Postfix) with ESMTP id 5D31A6B0031 for ; Fri, 27 Jun 2014 10:53:30 -0400 (EDT) Received: by mail-pb0-f52.google.com with SMTP id rq2so4630255pbb.25 for ; Fri, 27 Jun 2014 07:53:30 -0700 (PDT) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id hn2si14169417pbc.256.2014.06.27.07.53.29 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 27 Jun 2014 07:53:29 -0700 (PDT) Message-ID: <53AD84CE.20806@oracle.com> Date: Fri, 27 Jun 2014 10:50:54 -0400 From: Sasha Levin MIME-Version: 1.0 Subject: Re: mm: shm: hang in shmem_fallocate References: <52AE7B10.2080201@oracle.com> <52F6898A.50101@oracle.com> <52F82E62.2010709@oracle.com> <539A0FC8.8090504@oracle.com> <53A9A7D8.2020703@suse.cz> <53AC383F.3010007@oracle.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Vlastimil Babka , Konstantin Khlebnikov , Dave Jones , Andrew Morton , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, LKML On 06/27/2014 01:59 AM, Hugh Dickins wrote: >> > First, this: >> > >> > [ 681.267487] BUG: unable to handle kernel paging request at ffffea0003480048 >> > [ 681.268621] IP: zap_pte_range (mm/memory.c:1132) > Weird, I don't think we've seen anything like that before, have we? > I'm pretty sure it's not a consequence of my "index = min(index, end)", > but what it portends I don't know. Please confirm mm/memory.c:1132 - > that's the "if (PageAnon(page))" line, isn't it? Which indeed matches > the code below. So accessing page->mapping is causing an oops... Right, that's the correct line. At this point I'm pretty sure that it's somehow related to that one line patch since it reproduced fairly quickly after applying it, and when I removed it I didn't see it happening again during the overnight fuzzing. Thanks, Sasha -- 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