Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756749AbYJIWfl (ORCPT ); Thu, 9 Oct 2008 18:35:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753858AbYJIWfQ (ORCPT ); Thu, 9 Oct 2008 18:35:16 -0400 Received: from zcars04e.nortel.com ([47.129.242.56]:41409 "EHLO zcars04e.nortel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbYJIWfO (ORCPT ); Thu, 9 Oct 2008 18:35:14 -0400 Message-ID: <48EE871A.2030302@nortel.com> Date: Thu, 09 Oct 2008 16:35:06 -0600 From: "Chris Friesen" User-Agent: Mozilla Thunderbird 1.0.2-6 (X11/20050513) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Peter Zijlstra CC: Mathieu Desnoyers , Sam Ravnborg , linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Thomas Gleixner , Steven Rostedt Subject: Re: Building a tracing userspace tool in the kernel tree References: <20081009191626.GA29344@Krystal> <1223590513.7382.45.camel@lappy.programming.kicks-ass.net> In-Reply-To: <1223590513.7382.45.camel@lappy.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 09 Oct 2008 22:35:09.0628 (UTC) FILETIME=[4944DFC0:01C92A5F] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1172 Lines: 33 Peter Zijlstra wrote: > On Thu, 2008-10-09 at 15:16 -0400, Mathieu Desnoyers wrote: > >>Hi Sam, >> >>At the kernel summit, people seemed to be interested to have the basic >>userspace tools required to extract and pretty-print a trace available >>within the kernel tree. Therefore, what I am trying to do is something >>along the lines of >> >>ltt/usr/ >>ltt/usr/tracectl/ (control tracing) >>ltt/usr/tracesplice/ (splice buffers to disk) >>ltt/usr/tracecat/ (merge sort and format the binary buffers into >> human-readable text) > > > I'd rather have you provide that interface from the kernel much like > ftrace does. So we can do: > > # cat /debug/tracing/lttng/trace > Do we really want to reserve memory in the kernel to store all the data? Assuming not, do we really want to have to deal with filesystem namespaces in the kernel when interpreting which file we want to log to? Chris -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/