From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031015AbdDSSpS (ORCPT ); Wed, 19 Apr 2017 14:45:18 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:56333 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1030777AbdDSSpP (ORCPT ); Wed, 19 Apr 2017 14:45:15 -0400 Subject: Re: [PATCH] of: introduce event tracepoints for dynamic device_node lifecyle To: Steven Rostedt , Frank Rowand References: <1492475525-10827-1-git-send-email-tyreld@linux.vnet.ibm.com> <58F6AA35.2040902@gmail.com> <58F6C088.8020304@gmail.com> <20170418224953.685943a3@grimm.local.home> Cc: Tyrel Datwyler , robh+dt@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, nfont@linux.vnet.ibm.com, mpe@ellerman.id.au, mingo@redhat.com From: Tyrel Datwyler Date: Wed, 19 Apr 2017 11:45:07 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170418224953.685943a3@grimm.local.home> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17041918-0048-0000-0000-00000161E5FF X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006940; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00849718; UDB=6.00419604; IPR=6.00628351; BA=6.00005304; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015095; XFM=3.00000013; UTC=2017-04-19 18:45:13 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17041918-0049-0000-0000-000040A0ADE0 Message-Id: <641aa8ee-9b54-716a-77a1-076cafb95e3a@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-19_16:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1704190155 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/18/2017 07:49 PM, Steven Rostedt wrote: > On Tue, 18 Apr 2017 18:42:32 -0700 > Frank Rowand wrote: > >> And of course the other issue with using tracepoints is the extra space >> required to hold the tracepoint info. With the pr_debug() approach, the >> space usage can be easily removed for a production kernel via a config >> option. > > Now if you are saying you want to be able to enable debugging without > the tracing infrastructure I would agree. As the tracing infrastructure > is large. But I'm working on shrinking it more. The primary consumers of OF_DYNAMIC seem to be pseries and powernv where we are generally going to see the trace infrastructure enabled by default in production. -Tyrel > >> >> Tracepoints are wonderful technology, but not always the proper tool to >> use for debug info. > > But if you are going to have tracing enabled regardless, adding a few > more tracepoints isn't going to make the difference. > > -- Steve > >> >>> If Rob wants to convert printk() style data to trace data (and I can't >>> convince him otherwise) then I will have further comments on this specific >>> patch. >>>