From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756197AbaCFEoe (ORCPT ); Wed, 5 Mar 2014 23:44:34 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:19731 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751573AbaCFEod (ORCPT ); Wed, 5 Mar 2014 23:44:33 -0500 Message-ID: <5317FD2A.9020003@oracle.com> Date: Wed, 05 Mar 2014 23:44:26 -0500 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: "Kirill A. Shutemov" CC: Andrea Arcangeli , "linux-mm@kvack.org" , Andrew Morton , LKML Subject: Re: mm: kernel BUG at mm/huge_memory.c:2785! References: <530F3F0A.5040304@oracle.com> <20140227150313.3BA27E0098@blue.fi.intel.com> <53166881.1020504@oracle.com> <20140305135232.EC420E0098@blue.fi.intel.com> In-Reply-To: <20140305135232.EC420E0098@blue.fi.intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2014 08:52 AM, Kirill A. Shutemov wrote: > Sasha Levin wrote: >> On 02/27/2014 10:03 AM, Kirill A. Shutemov wrote: >>> Sasha Levin wrote: >>>>> Hi all, >>>>> >>>>> While fuzzing with trinity inside a KVM tools guest running latest -next kernel I've stumbled on the >>>>> following spew: >>>>> >>>>> [ 1428.146261] kernel BUG at mm/huge_memory.c:2785! >>> Hm, interesting. >>> >>> It seems we either failed to split huge page on vma split or it >>> materialized from under us. I don't see how it can happen: >>> >>> - it seems we do the right thing with vma_adjust_trans_huge() in >>> __split_vma(); >>> - we hold ->mmap_sem all the way from vm_munmap(). At least I don't see >>> a place where we could drop it; >>> >>> Andrea, any ideas? >> >> And a somewhat related issue (please correct me if I'm wrong): > > Yeah. Looks similar. And I still have no idea how it could happened. > > Do you trinity logs for the crash? I can't get it to reproduce with trinity logging enabled, I guess it makes it harder for the race to occur. I'll keep it running through the night but don't really have high hopes. Thanks, Sasha