From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-f44.google.com (mail-yh0-f44.google.com [209.85.213.44]) by kanga.kvack.org (Postfix) with ESMTP id BC2296B0035 for ; Wed, 5 Mar 2014 23:44:31 -0500 (EST) Received: by mail-yh0-f44.google.com with SMTP id f73so2151369yha.3 for ; Wed, 05 Mar 2014 20:44:31 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id v3si8051158yhv.124.2014.03.05.20.44.31 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 05 Mar 2014 20:44:31 -0800 (PST) Message-ID: <5317FD2A.9020003@oracle.com> Date: Wed, 05 Mar 2014 23:44:26 -0500 From: Sasha Levin MIME-Version: 1.0 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 Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Andrea Arcangeli , "linux-mm@kvack.org" , Andrew Morton , LKML 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 -- 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