From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f180.google.com (mail-ob0-f180.google.com [209.85.214.180]) by kanga.kvack.org (Postfix) with ESMTP id 78F156B00E2 for ; Mon, 9 Dec 2013 15:34:45 -0500 (EST) Received: by mail-ob0-f180.google.com with SMTP id wo20so4337130obc.11 for ; Mon, 09 Dec 2013 12:34:45 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id mx9si8452184obc.145.2013.12.09.12.34.43 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 09 Dec 2013 12:34:44 -0800 (PST) Message-ID: <52A6275F.4040007@oracle.com> Date: Mon, 09 Dec 2013 15:26:07 -0500 From: Sasha Levin MIME-Version: 1.0 Subject: Re: kernel BUG in munlock_vma_pages_range References: <52A3D0C3.1080504@oracle.com> <52A58E8A.3050401@suse.cz> <52A5F83F.4000207@oracle.com> <52A5F9EE.4010605@suse.cz> In-Reply-To: <52A5F9EE.4010605@suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka , Andrew Morton Cc: joern@logfs.org, mgorman@suse.de, Michel Lespinasse , riel@redhat.com, LKML , "linux-mm@kvack.org" On 12/09/2013 12:12 PM, Vlastimil Babka wrote: > On 12/09/2013 06:05 PM, Sasha Levin wrote: >> On 12/09/2013 04:34 AM, Vlastimil Babka wrote: >>> Hello, I will look at it, thanks. >>> Do you have specific reproduction instructions? >> >> Not really, the fuzzer hit it once and I've been unable to trigger it again. Looking at >> the piece of code involved it might have had something to do with hugetlbfs, so I'll crank >> up testing on that part. > > Thanks. Do you have trinity log and the .config file? I'm currently unable to even boot linux-next > with my config/setup due to a GPF. > Looking at code I wouldn't expect that it could encounter a tail page, without first encountering a > head page and skipping the whole huge page. At least in THP case, as TLB pages should be split when > a vma is split. As for hugetlbfs, it should be skipped for mlock/munlock operations completely. One > of these assumptions is probably failing here... If it helps, I've added a dump_page() in case we hit a tail page there and got: [ 980.172299] page:ffffea003e5e8040 count:0 mapcount:1 mapping: (null) index:0 x0 [ 980.173412] page flags: 0x2fffff80008000(tail) I can also add anything else in there to get other debug output if you think of something else useful. 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