1 <!DOCTYPE html PUBLIC
"-//W3C//DTD HTML 4.01 Transitional//EN">
4 <title>Linux Trace Toolkit Quickstart
</title>
8 <h1>Linux Trace Toolkit Quickstart
</h1>
10 Author : Mathieu Desnoyers, September
2005<br>
11 Last update : January
21st,
2009<br>
13 <h2>Table of Contents
</h2>
16 <li><a href=
"#intro" name=
"TOCintro">Introduction
</a></li>
17 <li><a href=
"#section1" name=
"TOCsection1">Installing LTTng and LTTV from
19 <li><a href=
"#section2" name=
"TOCsection2">Using LTTng and LTTV
</a></li>
20 <li><a href=
"#section3" name=
"TOCsection3">Adding kernel and user-space
22 <li><a href=
"#section4" name=
"TOCsection4">Creating Debian and RPM packages
29 <h2><a href=
"#TOCintro" name=
"intro">Introduction
</a></h2>
31 This document is made of four parts : the first one explains how
32 to install LTTng and LTTV from sources, the second one describes the steps
33 to follow to trace a system and view it. The third part explains
34 briefly how to add a new trace point to the kernel and to user space
35 applications. The fourth and last part explains how to create Debian or RPM
36 packages from the LTTng and LTTV sources.
39 These operations are made for installing the LTTng
0.86 tracer on a linux
2.6.X
40 kernel. You will also find instructions for installation of LTTV
0.12.x : the
41 Linux Trace Toolkit Viewer.
42 To see the list of compatibilities between LTTng, ltt-control, LTTV, please
45 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility
</a>
46 The lttng patch is necessary to have the tracing hooks in the kernel.
50 Supported architectures :
54 <li> PowerPC
32 and
64 bits
55 <li> ARM (with limited timestamping precision, e.g.
1HZ. Need
56 architecture-specific support for better precision)
62 <li> PowerPC
32 and
64 bits
63 <li> Possibly others. Takes care of endianness and type size difference between
64 the LTTng traces and the LTTV analysis tool.
69 <h2><a href=
"#TOCsection2" name=
"section2">Installation from sources
</a></h2>
72 <li>Prerequisites
</li>
75 Tools needed to follow the package download steps :
83 You have to install the standard development libraries and programs necessary
86 (from Documentation/Changes in the Linux kernel tree)
87 <li>Gnu C \tnbsp;
2.95.3 \tnbsp; # gcc --version
88 <li>Gnu make \tnbsp;
3.79.1 \tnbsp; # make --version
89 <li>binutils \tnbsp;
2.12 \tnbsp; # ld -v
90 <li>util-linux \tnbsp;
2.10o \tnbsp; # fdformat --version
91 <li>module-init-tools \tnbsp;
0.9.10 \tnbsp; # depmod -V
94 You might also want to have libncurses5 to have the text mode kernel
95 configuration menu, but there are alternatives.
98 Prerequisites for LTTV
0.x.x installation are :
100 <li>gcc
3.2 or better
101 <li>gtk
2.4 or better development libraries
102 (Debian : libgtk2.0, libgtk2.0-dev)
103 (Fedora : gtk2, gtk2-devel)
104 note : For Fedora users : this might require at least core
3 from Fedora,
105 or you might have to compile your own GTK2 library.
106 <li>glib
2.4 or better development libraries
107 (Debian : libglib2.0-
0, libglib2.0-dev)
108 (Fedora : glib2, glib2-devel)
109 <li>libpopt development libraries
110 (Debian : libpopt0, libpopt-dev)
112 <li>libpango development libraries
113 (Debian : libpango1.0, libpango1.0-dev)
114 (Fedora : pango, pango-devel)
115 <li>libc6 development librairies
116 (Debian : libc6, libc6-dev)
117 (Fedora : glibc, glibc)
122 See the list of compatibilities between LTTng, ltt-control and LTTV at :
124 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
125 versions compatibility
</a>.
128 * Getting the LTTng packages
133 (see http://ltt.polymtl.ca/lttng for package listing)
134 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
135 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
138 * Getting LTTng kernel sources
142 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
143 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
145 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
146 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
149 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
152 * Installing a LTTng kernel
155 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
156 make menuconfig (or make xconfig or make config)
157 Select the < Help
> button if you are not familiar with kernel
159 Items preceded by [*] means they has to be built into the kernel.
160 Items preceded by [M] means they has to be built as modules.
161 Items preceded by [ ] means they should be removed.
162 go to the
"General setup" section
163 Select the following options :
164 [*] Prompt for development and/or incomplete code/drivers
166 [*] Activate userspace markers ABI (experimental, optional)
167 [*] Immediate value optimization (optional)
168 [*] Linux Trace Toolkit Next Generation (LTTng) --->
169 <M> or <*
> Compile lttng tracing probes
170 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
171 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
172 <M> or <*
> Linux Trace Toolkit Serializer
173 <M> or <*
> Linux Trace Toolkit Marker Control
174 <M> or <*
> Linux Trace Toolkit Tracer
175 [*] Align Linux Trace Toolkit Traces
176 <M> or <*
> Support logging events from userspace
177 [*] Support trace extraction from crash dump
178 <M> or <*
> Linux Trace Toolkit Trace Controller
179 <M> or <*
> Linux Trace Toolkit State Dump
185 (if necessary, create a initrd with mkinitrd or your preferate alternative)
186 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
191 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
194 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
195 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
196 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
197 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
198 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
199 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
200 that comes first is the default kernel)
202 select the right entry at the yaboot prompt (see choices : tab, select : type
203 the kernel name followed by enter)
204 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
209 * Editing the system wide configuration
211 You must activate debugfs and specify a mount point. This is typically done in
212 fstab such that it happens at boot time.
214 If you have never used DebugFS before, these operation would do this for you :
217 cp /etc/fstab /etc/fstab.lttng.bkp
218 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
220 then, rebooting or issuing the following command will activate debugfs :
224 You need to load the LTT modules to be able to control tracing from user
225 space. This is done by issuing the following commands. Note however
226 these commands load all LTT modules. Depending on what options you chose to
227 compile statically, you may not need to issue all these commands.
229 modprobe ltt-trace-control
230 modprobe ltt-marker-control
232 modprobe ltt-serialize
235 modprobe kernel-trace
241 modprobe syscall-trace
243 #if locking tracing is wanted, uncomment the following
244 #modprobe lockdep-trace
246 If you want to have complete information about the kernel state (including all
247 the process names), you need to load the ltt-statedump module. This is done by
248 issuing the command :
250 modprobe ltt-statedump
252 You can automate at boot time loading the ltt-control module by :
254 cp /etc/modules /etc/modules.bkp
255 echo ltt-trace-control
>> /etc/modules
256 echo ltt-marker-control
>> /etc/modules
257 echo ltt-tracer
>> /etc/modules
258 echo ltt-serialize
>> /etc/modules
259 echo ltt-relay
>> /etc/modules
260 echo ipc-trace
>> /etc/modules
261 echo kernel-trace
>> /etc/modules
262 echo mm-trace
>> /etc/modules
263 echo net-trace
>> /etc/modules
264 echo fs-trace
>> /etc/modules
265 echo jbd2-trace
>> /etc/modules
266 echo ext4-trace
>> /etc/modules
267 echo syscall-trace
>> /etc/modules
268 echo trap-trace
>> /etc/modules
269 #if locking tracing is wanted, uncomment the following
270 #echo lockdep-trace
>> /etc/modules
273 * Getting and installing the ltt-control package (on the traced machine)
274 (note : the ltt-control package contains lttd and lttctl. Although it has the
275 same name as the ltt-control kernel module, they are *not* the same thing.)
278 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
279 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
280 cd ltt-control-
0.x-xxxx2006
281 (refer to README to see the development libraries that must be installed on you
290 Make sure you selected the kernel menuconfig option :
291 <M> or <*
> Support logging events from userspace
292 And that the ltt-userspace-event kernel module is loaded if selected as a
295 Simple userspace tracing is available through
296 echo
"some text to record" > /mnt/debugfs/ltt/write_event
298 It will appear in the trace under event :
303 * Getting and installing the LTTV package (on the visualisation machine, same or
304 different from the visualisation machine)
308 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
309 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
310 cd lttv-
0.x.xx-xxxx2008
311 (refer to README to see the development libraries that must be installed on your
318 * Getting and installing the markers-userspace package for user space tracing
320 See http://ltt.polymtl.ca/packages/markers-userspace-
0.5.tar.bz2 or more recent.
324 ***********************************************************
325 ** Section
3 * Using LTTng and LTTV **
326 ***********************************************************
328 * IMPORTANT : Arm Linux Kernel Markers after each boot
332 * Use graphical LTTV to control tracing and analyse traces
334 lttv-gui (or /usr/local/bin/lttv-gui)
335 - Spot the
"Tracing Control" icon : click on it
336 (it's a traffic light icon)
337 - enter the root password
341 * You should now see a trace
343 * Use text mode LTTng to control tracing
345 The tracing can be controlled from a terminal by using the lttctl command (as
350 lttctl -C -w /tmp/trace1 trace1
352 Stop tracing and destroy trace channels :
356 see lttctl --help for details.
358 (note : to see if the buffers has been filled, look at the dmesg output after
359 lttctl -R or after stopping tracing from the GUI, it will show an event lost
360 count. If it is the case, try using larger buffers. See lttctl --help to learn
361 how. lttv now also shows event lost messages in the console when loading a trace
362 with missing events or lost subbuffers.)
366 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
367 graphical plugins available.
369 For example, a simple trace dump in text format is available with :
371 lttv -m textDump -t /tmp/trace
373 see lttv -m textDump --help for detailed command line options of textDump.
375 It is, in the current state of the project, very useful to use
"grep" on the
376 text output to filter by specific event fields. You can later copy the timestamp
377 of the events to the clipboard and paste them in the GUI by clicking on the
378 bottom right label
"Current time". Support for this type of filtering should
379 be added to the filter module soon.
383 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
384 hybrid. It can be especially useful when studying big workloads on a long period
387 When using this mode, the most important, low rate control information will be
388 recorded during all the trace by lttd (i.e. process creation/exit). The high
389 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
390 flight recorder buffer (now named flight-channelname_X).
392 The following lttctl commands take an hybrid trace :
394 Create trace channel, start lttd on normal channels, start tracing:
395 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
397 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
398 lttctl -D -w /tmp/trace2 trace2
400 Each
"overwrite" channel is flight recorder channel.
402 * Flight recorder mode
404 The flight recorder mode writes data into overwritten buffers for all channels,
405 including control channels, except for the facilities tracefiles. It consists of
406 setting all channels to
"overwrite".
408 The following lttctl commands take a flight recorder trace :
410 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
412 lttctl -D -w /tmp/trace3 trace3
415 **************************************************************
416 ** Section
4 * Adding new instrumentations with the markers **
417 **************************************************************
419 See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
422 * Add new events to userspace programs with userspace markers
423 http://ltt.polymtl.ca/packages/
425 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
426 allows inserting markers in executables and libraries, currently only on x86_32
429 ***********************************************************
430 ** Section
5 * Creating Debian or RPM packages **
431 ***********************************************************
433 * Create custom LTTV Debian packages
435 Use : dpkg-buildpackage -rfakeroot
437 You should then have your LTTV .deb files created for your architecture.
439 * Create custom LTTng packages
441 For building LTTng Debian packages :
443 Get the build tree with patches applies as explained in section
2.
445 make menuconfig (or xconfig or config) (customize your configuration)
446 make-kpkg kernel_image
448 You will then see your freshly created .deb in /usr/src. Install it with
449 dpkg -i /usr/src/(image-name).deb
451 Then, follow the section
"Editing the system wide configuration" in section
2.