From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7615FC10DCE for ; Thu, 12 Mar 2020 11:48:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A89A2071B for ; Thu, 12 Mar 2020 11:48:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727027AbgCLLs5 (ORCPT ); Thu, 12 Mar 2020 07:48:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:7118 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726044AbgCLLs4 (ORCPT ); Thu, 12 Mar 2020 07:48:56 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02CBiYWo140092 for ; Thu, 12 Mar 2020 07:48:56 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2yqkw31vub-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 12 Mar 2020 07:48:53 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 12 Mar 2020 11:48:36 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp02.uk.ibm.com (192.168.101.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 12 Mar 2020 11:48:33 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02CBmWg229950146 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Mar 2020 11:48:32 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F3E584C062; Thu, 12 Mar 2020 11:48:31 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C16104C052; Thu, 12 Mar 2020 11:48:31 +0000 (GMT) Received: from oc3784624756.ibm.com (unknown [9.152.212.155]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 12 Mar 2020 11:48:31 +0000 (GMT) Subject: Re: [PATCH] perf documentation: Add desription forHEADER_TRACING_DATA To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, gor@linux.ibm.com, sumanthk@linux.ibm.com, heiko.carstens@de.ibm.com References: <20200303070846.18335-1-tmricht@linux.ibm.com> <20200311135815.GD19277@kernel.org> From: Thomas Richter Organization: IBM Date: Thu, 12 Mar 2020 12:48:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200311135815.GD19277@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 20031211-0008-0000-0000-0000035C0F06 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20031211-0009-0000-0000-00004A7D5896 Message-Id: <747c8b92-a342-3e0c-4232-19df02250496@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-03-12_03:2020-03-11,2020-03-12 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 mlxscore=0 malwarescore=0 adultscore=0 bulkscore=0 lowpriorityscore=0 phishscore=0 clxscore=1015 priorityscore=1501 suspectscore=0 spamscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003120064 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/11/20 2:58 PM, Arnaldo Carvalho de Melo wrote: > Em Tue, Mar 03, 2020 at 08:08:46AM +0100, Thomas Richter escreveu: >> Add description and layout in the perf.data file for >> the header part describing trace data used in commands >> perf record -e XXX >> where XXX is a probe or tracepoint. > > Did you write this from scratch? I was going thru it and couldn't find > what that "Note member 'ftrace_count' can be zero." refers to, couldn't > find this ftrace_counter, is this outdated? > > [root@five ~]# find /sys/kernel/debug/tracing/events/ -type f | xargs grep ftrace_count > [root@five ~]# find /sys/kernel/debug/tracing/events/ -name ftrace_count > [root@five ~]# uname -a > Linux five 5.5.5-200.fc31.x86_64 #1 SMP Wed Feb 19 23:28:07 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux > [root@five ~]# > > The part about using a probe and then go on dissecting it is really > nice, I'll try reproducing it soon, > > Thanks, > Arnaldo, yes, I wrote this from scratch. I decided to invest some time into the documentation after I have spent nearly 3 week in debugging why commands perf record -e probe:vfs_getname followed by perf report did not print the file name on s390. Remember we talked about failing test case 65: Check open filename arg using perf trace + vfs_getname. (Steven Rostedt and Masami Hiramatsu helped me on this). On ftrace_count: This is not a file available in /sys/kernel/debug/tracing. It is a value saved in function tracing_data_get record_ftrace_files copy_event_system --> Check for some format file in directories /sys/kernel/debug/tracing/events/ftrace/*/ Depending on what probe was defined, there is no hit and zero is written to the output. Hope this helps. -- Thomas Richter, Dept 3252, IBM s390 Linux Development, Boeblingen, Germany -- Vorsitzender des Aufsichtsrats: Matthias Hartmann Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294