Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940018AbdDTCiL (ORCPT ); Wed, 19 Apr 2017 22:38:11 -0400 Received: from mail-io0-f194.google.com ([209.85.223.194]:35107 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764848AbdDTCiH (ORCPT ); Wed, 19 Apr 2017 22:38:07 -0400 Subject: Re: [PATCH] of: introduce event tracepoints for dynamic device_node lifecyle To: Tyrel Datwyler , Steven Rostedt 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> <641aa8ee-9b54-716a-77a1-076cafb95e3a@linux.vnet.ibm.com> Cc: 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: Frank Rowand Message-ID: <58F81EF4.5070304@gmail.com> Date: Wed, 19 Apr 2017 19:37:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <641aa8ee-9b54-716a-77a1-076cafb95e3a@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1355 Lines: 44 On 04/19/17 11:45, Tyrel Datwyler wrote: > 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. Another primary consumer will be overlays for ARM expansion boards. Still a work in progress. -Frank > > -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. >>>> > > . >