From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id 5B3016B025F for ; Thu, 11 Jan 2018 05:08:53 -0500 (EST) Received: by mail-qk0-f200.google.com with SMTP id d125so2216432qkb.8 for ; Thu, 11 Jan 2018 02:08:53 -0800 (PST) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id o48si5097312qto.20.2018.01.11.02.08.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 11 Jan 2018 02:08:52 -0800 (PST) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0BA4YB9097359 for ; Thu, 11 Jan 2018 05:08:51 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0a-001b2d01.pphosted.com with ESMTP id 2fe307y5kn-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 11 Jan 2018 05:08:50 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 11 Jan 2018 10:08:47 -0000 Subject: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE 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> <87mv1phptq.fsf@concordia.ellerman.id.au> <7a44f42e-39d0-1c4b-19e0-7df1b0842c18@linux.vnet.ibm.com> <87tvvw80f2.fsf@concordia.ellerman.id.au> <96458c0a-e273-3fb9-a33b-f6f2d536f90b@linux.vnet.ibm.com> <20180109161355.GL1732@dhcp22.suse.cz> From: Anshuman Khandual Date: Thu, 11 Jan 2018 15:38:37 +0530 MIME-Version: 1.0 In-Reply-To: <20180109161355.GL1732@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko , Anshuman Khandual Cc: Michael Ellerman , 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 On 01/09/2018 09:43 PM, Michal Hocko wrote: > On Tue 09-01-18 17:18:38, Anshuman Khandual wrote: >> On 01/09/2018 03:42 AM, Michael Ellerman wrote: >>> Anshuman Khandual writes: >>> >>>> On 01/07/2018 04:56 PM, Michael Ellerman wrote: >>>>> 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. >>>> >>>> POWER9, RHEL 7.4, gcc (GCC) 4.8.5 20150623, GNU Make 3.82 etc. >>> >>> So what does readelf -a of /bin/sed look like? >> >> Please find here. > > Did you manage to catch _who_ is requesting that anonymous mapping? Do > you need a help with the debugging patch? Not yet, will get back on this. -- 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