From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756107Ab2HQNzZ (ORCPT ); Fri, 17 Aug 2012 09:55:25 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:2942 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752240Ab2HQNzS (ORCPT ); Fri, 17 Aug 2012 09:55:18 -0400 X-Authority-Analysis: v=2.0 cv=IOWA+3TG c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=LtHv6dTpUIwA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=LKy4QqaoLnIA:10 a=meVymXHHAAAA:8 a=0RgcGhzwGWWYyDXlZZ0A:9 a=PUjeQqilurYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-ID: <1345211714.3708.24.camel@gandalf.local.home> Subject: Re: [RFC PATCH 1/1] trace: Move trace event enable from fs_initcall to early_initcall From: Steven Rostedt To: Ezequiel Garcia Cc: linux-kernel@vger.kernel.org, Pekka Enberg , tim.bird@am.sony.com, lizefan@huawei.com, Frederic Weisbecker , Ingo Molnar Date: Fri, 17 Aug 2012 09:55:14 -0400 In-Reply-To: References: <1345043907-18299-1-git-send-email-elezegarcia@gmail.com> <1345151883.3708.7.camel@gandalf.local.home> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-08-17 at 08:01 -0300, Ezequiel Garcia wrote: > Regarding the 'complete solution': to be able to capture events from > the very beggining... > Have you thought about this? > Could you give me a hint on how could I implement it? How far in the "beginning"? Before memory is set up? I wouldn't do that. I have in the past (set up before memory was finished being initialized), but things have changed since then. One thing that we could do for those that want really early tracing, is to add a config option to add a static temporary ring buffer, that gets copied into the default ring buffer after memory is set up. That may be the easiest way. Once memory is set up, the ring buffer can be allocated and events can be traced, but the ring buffer needs to be set up first. All it would take is some calls in init/main.c start_kernel() to the initialization. -- Steve