From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940261AbdDTKpF (ORCPT ); Thu, 20 Apr 2017 06:45:05 -0400 Received: from mail-io0-f193.google.com ([209.85.223.193]:33627 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934597AbdDTKo7 (ORCPT ); Thu, 20 Apr 2017 06:44:59 -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> <58F81EF4.5070304@gmail.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: <58F89110.1020904@gmail.com> Date: Thu, 20 Apr 2017 03:44:32 -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: <58F81EF4.5070304@gmail.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 On 04/19/17 19:37, Frank Rowand wrote: > 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. And dynamic configuration for the FPGA folks. > -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. >>>>> >> >> . >> > > . >