From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754357AbaCFEcM (ORCPT ); Wed, 5 Mar 2014 23:32:12 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:48266 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752275AbaCFEcJ (ORCPT ); Wed, 5 Mar 2014 23:32:09 -0500 Message-ID: <5317FA3B.8060900@oracle.com> Date: Wed, 05 Mar 2014 23:31:55 -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: Naoya Horiguchi CC: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, riel@redhat.com Subject: Re: [PATCH] mm: add pte_present() check on existing hugetlb_entry callbacks References: <53126861.7040107@oracle.com> <1393822946-26871-1-git-send-email-n-horiguchi@ah.jp.nec.com> <5314E0CD.6070308@oracle.com> <5314F661.30202@oracle.com> <1393968743-imrxpynb@n-horiguchi@ah.jp.nec.com> <531657DC.4050204@oracle.com> <1393976967-lnmm5xcs@n-horiguchi@ah.jp.nec.com> In-Reply-To: <1393976967-lnmm5xcs@n-horiguchi@ah.jp.nec.com> Content-Type: text/plain; charset=ISO-2022-JP 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 03/04/2014 06:49 PM, Naoya Horiguchi wrote: > On Tue, Mar 04, 2014 at 05:46:52PM -0500, Sasha Levin wrote: >> On 03/04/2014 04:32 PM, Naoya Horiguchi wrote: >>> # sorry if duplicate message >>> >>> On Mon, Mar 03, 2014 at 04:38:41PM -0500, Sasha Levin wrote: >>>> On 03/03/2014 03:06 PM, Sasha Levin wrote: >>>>> On 03/03/2014 12:02 AM, Naoya Horiguchi wrote: >>>>>> Hi Sasha, >>>>>> >>>>>>>> I can confirm that with this patch the lockdep issue is gone. However, the NULL deref in >>>>>>>> walk_pte_range() and the BUG at mm/hugemem.c:3580 still appear. >>>>>> I spotted the cause of this problem. >>>>>> Could you try testing if this patch fixes it? >>>>> >>>>> I'm seeing a different failure with this patch: >>>> >>>> And the NULL deref still happens. >>> >>> I don't yet find out the root reason why this issue remains. >>> So I tried to run trinity myself but the problem didn't reproduce. >>> (I did simply like "./trinity --group vm --dangerous" a few hours.) >>> Could you show more detail or tips about how the problem occurs? >> >> I run it as root in a disposable vm, that may be the difference here. > > Sorry, I didn't write it but I also run it as root on VM, so condition is > the same. It might depend on kernel config, so I'm now trying the config > you previously gave me, but it doesn't boot correctly on my environment > (panic in initialization). I may need some time to get over this. I'd be happy to help with anything off-list, it shouldn't be too difficult to get that kernel to boot :) I've also reverted the page walker series for now, it makes it impossible to test anything else since it seems that hitting one of the issues is quite easy. Thanks, Sasha