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=-0.7 required=3.0 tests=FORGED_MUA_MOZILLA, 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 997D1C32771 for ; Mon, 6 Jan 2020 08:30:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77A29215A4 for ; Mon, 6 Jan 2020 08:30:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726050AbgAFIa0 (ORCPT ); Mon, 6 Jan 2020 03:30:26 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:4020 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgAFIa0 (ORCPT ); Mon, 6 Jan 2020 03:30:26 -0500 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0068S7Nt101653 for ; Mon, 6 Jan 2020 03:30:24 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2xb92kt47w-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 06 Jan 2020 03:30:24 -0500 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 6 Jan 2020 08:30:22 -0000 Received: from b06avi18878370.portsmouth.uk.ibm.com (9.149.26.194) by e06smtp03.uk.ibm.com (192.168.101.133) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 6 Jan 2020 08:30:21 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0068UKgI34865568 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 6 Jan 2020 08:30:20 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8AC71AE059 for ; Mon, 6 Jan 2020 08:30:20 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2EF41AE064 for ; Mon, 6 Jan 2020 08:30:20 +0000 (GMT) Received: from [9.199.159.50] (unknown [9.199.159.50]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP for ; Mon, 6 Jan 2020 08:30:20 +0000 (GMT) From: Ritesh Harjani Subject: About BUFFER_TRACE macro in include/linux/jbd2.h To: linux-ext4@vger.kernel.org Date: Mon, 6 Jan 2020 14:00:19 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 20010608-0012-0000-0000-0000037AD0C9 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20010608-0013-0000-0000-000021B6E8FC Message-Id: <20200106083020.2EF41AE064@d06av26.portsmouth.uk.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2020-01-06_01:2020-01-06,2020-01-06 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 adultscore=0 lowpriorityscore=0 spamscore=0 phishscore=0 priorityscore=1501 impostorscore=0 bulkscore=0 malwarescore=0 mlxlogscore=999 suspectscore=1 clxscore=1031 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-2001060078 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Hello Community, A very happy new year to all of you!! :) Had some query on BUFFER_TRACE macro. Here it goes:- While debugging some issue w.r.t jbd2/bh I came across this empty macro definition of BUFFER_TRACE in include/linux/jbd2.h. Though this is called from multiple places, but I could not find any definition of this as such. I could see some patches on mailing list which are still calling this macro. So that means I am definitely missing something here. Could you please help me understand how can one use this "BUFFER_TRACE" macro for debugging? I could not find any ftrace event related to this macro. For my debugging as of now I ended up creating a file in include/trace/events/buffer_debug.h and added the definition of BUFFER_TRACE macro there. On more googling I did find some old patch which enabled CONFIG_BUFFER_DEBUG. http://people.redhat.com/sct/patches/ext3-2.4/for-2.4.19/98-debug/00-ext3-debug.patch But this seemed pretty old and I could not find anything latest on this which is related to above patch. Any pointers pls? -ritesh