From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas-Mich Richter Subject: Re: [PATCH 2/2] perf record: wrong size in perf_record_mmap for last kernel module Date: Tue, 25 Jul 2017 10:26:14 +0200 Message-ID: <1410d73a-ad86-2c14-2e4f-5c4e174f5eba@linux.vnet.ibm.com> References: <20170724143514.55574-1-tmricht@linux.vnet.ibm.com> <20170724143514.55574-2-tmricht@linux.vnet.ibm.com> <20170725065812.GB28831@sejong> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:43554 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751202AbdGYI0U (ORCPT ); Tue, 25 Jul 2017 04:26:20 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6P8OvmG044052 for ; Tue, 25 Jul 2017 04:26:20 -0400 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bwvyycwhx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 25 Jul 2017 04:26:20 -0400 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 25 Jul 2017 09:26:18 +0100 In-Reply-To: <20170725065812.GB28831@sejong> Content-Language: en-IE Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Namhyung Kim Cc: brueckner@linux.vnet.ibm.com, zvonko.kosic@de.ibm.com, linux-perf-users@vger.kernel.org, acme@kernel.org, kernel-team@lge.com On 07/25/2017 08:58 AM, Namhyung Kim wrote: > On Mon, Jul 24, 2017 at 04:35:14PM +0200, Thomas Richter wrote: >> During work on perf report for s390 I ran into the following issue: [...] > > Did you hit a real problem with this? I think it doesn't affect > symbol resolution anyway. I saw a related problem before though.. Sure, that is why I startet digging.... Here is the output of perf report which triggered my investigation last week: 0.79% 0.00% sshd [qeth_l2] [k] 0xfffffc007fb2dbb2 | ---0x44da skb_vlan_push iplstart As said before qeth_l2.ko is the last kernel modules listed in /proc/modules. > https://lkml.org/lkml/2017/6/23/63 > > In this case a module was unloaded after perf record, and loaded again > (but on a slightly different address) before perf report. The record > data has old address but perf report tried to use current address so > it could not find symbols from the module. I need to update the > patchset.. Ok I have looked at this patch series but still do not understand every detail of it. I have not seen it before, I do not follow the linux-kernel mailing list. This amount of traffic kills me... (or my thunderbird) and I end up deleting the incoming mails all the time. However I do follow linux-perf-user mailing list. I found this sufficient because right now I only work on the perf user tool and not the kernel part. > > Anyway I'm ok with this patch. > > Thanks, > Namhyung > [...] -- Thomas Richter, Dept 3303, IBM LTC Boeblingen Germany -- Vorsitzende des Aufsichtsrats: Martina Koederitz Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294