Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753513AbeAGL1E (ORCPT + 1 other); Sun, 7 Jan 2018 06:27:04 -0500 Received: from ozlabs.org ([103.22.144.67]:41045 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753061AbeAGL1B (ORCPT ); Sun, 7 Jan 2018 06:27:01 -0500 From: Michael Ellerman To: Michal Hocko , Anshuman Khandual Cc: akpm@linux-foundation.org, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au, broonie@kernel.org Subject: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE (was: Re: mmotm 2018-01-04-16-19 uploaded) In-Reply-To: <20180107090229.GB24862@dhcp22.suse.cz> References: <5a4ec4bc.u5I/HzCSE6TLVn02%akpm@linux-foundation.org> <7e35e16a-d71c-2ec8-03ed-b07c2af562f8@linux.vnet.ibm.com> <20180105084631.GG2801@dhcp22.suse.cz> <20180107090229.GB24862@dhcp22.suse.cz> Date: Sun, 07 Jan 2018 22:26:57 +1100 Message-ID: <87mv1phptq.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Michal Hocko writes: > On Sun 07-01-18 12:19:32, Anshuman Khandual wrote: >> On 01/05/2018 02:16 PM, Michal Hocko wrote: > [...] >> > Could you give us more information about the failure please. Debugging >> > patch from http://lkml.kernel.org/r/20171218091302.GL16951@dhcp22.suse.cz >> > should help to see what is the clashing VMA. >> >> Seems like its re-requesting the same mapping again. > > It always seems to be the same mapping which is a bit strange as we > have multiple binaries here. Are these binaries any special? Does this > happen to all bianries (except for init which has obviously started > successfully)? Could you add an additional debugging (at the do_mmap > layer) to see who is requesting the mapping for the first time? > >> [ 23.423642] 9148 (sed): Uhuuh, elf segment at 0000000010030000 requested but the memory is mapped already >> [ 23.423706] requested [10030000, 10040000] mapped [10030000, 10040000] 100073 anon > > I also find it a bit unexpected that this is an anonymous mapping > because the elf loader should always map a file backed one. Anshuman what machine is this on, and what distro and toolchain is it running? I don't see this on any of my machines, so I wonder if this is toolchain/distro specific. cheers