Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754246AbYAPUk3 (ORCPT ); Wed, 16 Jan 2008 15:40:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750896AbYAPUkR (ORCPT ); Wed, 16 Jan 2008 15:40:17 -0500 Received: from outbound-sin.frontbridge.com ([207.46.51.80]:6705 "EHLO outbound4-sin-R.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751269AbYAPUkO (ORCPT ); Wed, 16 Jan 2008 15:40:14 -0500 X-BigFish: VP X-MS-Exchange-Organization-Antispam-Report: OrigIP: 160.33.98.75;Service: EHS Message-ID: <478E6CDA.6090004@am.sony.com> Date: Wed, 16 Jan 2008 12:45:14 -0800 From: Tim Bird User-Agent: Thunderbird 1.5.0.4 (X11/20060614) MIME-Version: 1.0 To: Mathieu Desnoyers CC: Steven Rostedt , LKML , Ingo Molnar , Linus Torvalds , Andrew Morton , Peter Zijlstra , Christoph Hellwig , Gregory Haskins , Arnaldo Carvalho de Melo , Thomas Gleixner , Sam Ravnborg , "Frank Ch. Eigler" , Steven Rostedt , Paul Mackerras , Daniel Walker Subject: Re: [RFC PATCH 16/22 -v2] add get_monotonic_cycles References: <20080115220824.GB22242@Krystal> <20080116031730.GA2164@Krystal> <20080116145604.GB31329@Krystal> <20080116152838.GA970@Krystal> <20080116170011.GA3651@Krystal> <20080116201713.GA14336@Krystal> In-Reply-To: <20080116201713.GA14336@Krystal> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 16 Jan 2008 20:40:07.0725 (UTC) FILETIME=[FB1ECDD0:01C8587F] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1823 Lines: 61 Mathieu Desnoyers wrote: > If LTTng is already ported to your specific kernel, the learning-curve > is not big at all. Here is what the latency_tracer over LTTng guide > could look like : > > Well, once you have LTTng in your kernel and have compiled and installed > the ltt-control and lttv packages (configure, make, make install), all > that would be needed is : > > (there may be some bits in the QUICKSTART GUIDE on > http://ltt.polymtl.ca, like adding the debugfs mount to fstab and make sure > the LTTng modules are loaded) > > #arm all the markers > ltt-armall > #start lttng tracing > lttctl -n test -t /tmp/trace1 -d -l /mnt/debugfs/ltt > > -> start latency tracer > -> stop latency tracer > -> trigger latency tracer dump > > While the tracing is active, trigger the condition... > > (rince, repeat, can handle multiple latency tracer dumps) > > #stop lttng tracing > lttctl -n test -R > #disarm all markers > ltt-disarmall > > You can easily test the trace with : > lttv -m textDump -t /tmp/trace1 > > Your users would issue something like : > > lttv -m latencytracerDump -t /tmp/trace1 No offense, but this is still quite a bit harder than: echo 1 >/proc/something ... wait a bit ... cat /proc/something (substitute /sys or /debugfs where appropriate) Having to compile something (besides the kernel) for the target is sometimes a major hassle. I avoided it completely with KFT. -- Tim ============================= Tim Bird Architecture Group Chair, CE Linux Forum Senior Staff Engineer, Sony Corporation of America ============================= -- 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/