1 <!DOCTYPE html PUBLIC
"-//W3C//DTD HTML 4.01 Transitional//EN">
4 <title>Linux Trace Toolkit Next Generation User Documentation
</title>
8 <h1>Linux Trace Toolkit Next Generation User Documentation
</h1>
10 Author : Mathieu Desnoyers, September
2005<br>
11 Last update : January
21st,
2009<br>
12 (originally known as the LTTng QUICKSTART guide)
14 <h2>Table of Contents
</h2>
17 <li><a href=
"#intro" name=
"TOCintro">Introduction
</a></li>
18 <li><a href=
"#section1" name=
"TOCsection1">Installing LTTng and LTTV from
20 <li><a href=
"#section2" name=
"TOCsection2">Using LTTng and LTTV
</a></li>
21 <li><a href=
"#section3" name=
"TOCsection3">Adding kernel and user-space
23 <li><a href=
"#section4" name=
"TOCsection4">Creating Debian and RPM packages
30 <h2><a href=
"#TOCintro" name=
"intro">Introduction
</a></h2>
32 This document is made of four parts : the first one explains how
33 to install LTTng and LTTV from sources, the second one describes the steps
34 to follow to trace a system and view it. The third part explains
35 briefly how to add a new trace point to the kernel and to user space
36 applications. The fourth and last part explains how to create Debian or RPM
37 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=
"#TOCsection1" name=
"section1">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
87 (from Documentation/Changes in the Linux kernel tree)
88 Gnu C
2.95.3 # gcc --version
89 Gnu make
3.79.1 # make --version
91 util-linux
2.10o # fdformat --version
92 module-init-tools
0.9.10 # depmod -V
96 You might also want to have libncurses5 to have the text mode kernel
97 configuration menu, but there are alternatives.
100 Prerequisites for LTTV
0.x.x installation are :
104 gtk
2.4 or better development libraries
105 (Debian : libgtk2.0, libgtk2.0-dev)
106 (Fedora : gtk2, gtk2-devel)
107 note : For Fedora users : this might require at least core
3 from Fedora,
108 or you might have to compile your own GTK2 library.
109 glib
2.4 or better development libraries
110 (Debian : libglib2.0-
0, libglib2.0-dev)
111 (Fedora : glib2, glib2-devel)
112 libpopt development libraries
113 (Debian : libpopt0, libpopt-dev)
115 libpango development libraries
116 (Debian : libpango1.0, libpango1.0-dev)
117 (Fedora : pango, pango-devel)
118 libc6 development librairies
119 (Debian : libc6, libc6-dev)
120 (Fedora : glibc, glibc)
127 See the list of compatibilities between LTTng, ltt-control and LTTV at :
129 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
130 versions compatibility
</a>.
133 <li>Getting the LTTng packages
</li>
139 (see http://ltt.polymtl.ca/lttng for package listing)
140 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
141 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
145 <li>Getting LTTng kernel sources
</li>
150 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
151 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
153 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
154 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
157 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
161 <li>Installing a LTTng kernel
</li>
165 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
166 make menuconfig (or make xconfig or make config)
167 Select the < Help
> button if you are not familiar with kernel
169 Items preceded by [*] means they has to be built into the kernel.
170 Items preceded by [M] means they has to be built as modules.
171 Items preceded by [ ] means they should be removed.
172 go to the
"General setup" section
173 Select the following options :
174 [*] Prompt for development and/or incomplete code/drivers
176 [*] Activate userspace markers ABI (experimental, optional)
177 [*] Immediate value optimization (optional)
178 [*] Linux Trace Toolkit Next Generation (LTTng) --->
179 <M> or <*
> Compile lttng tracing probes
180 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
181 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
182 <M> or <*
> Linux Trace Toolkit Serializer
183 <M> or <*
> Linux Trace Toolkit Marker Control
184 <M> or <*
> Linux Trace Toolkit Tracer
185 [*] Align Linux Trace Toolkit Traces
186 <M> or <*
> Support logging events from userspace
187 [*] Support trace extraction from crash dump
188 <M> or <*
> Linux Trace Toolkit Trace Controller
189 <M> or <*
> Linux Trace Toolkit State Dump
195 (if necessary, create a initrd with mkinitrd or your preferate alternative)
196 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
201 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
204 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
205 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
206 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
207 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
208 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
209 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
210 that comes first is the default kernel)
212 select the right entry at the yaboot prompt (see choices : tab, select : type
213 the kernel name followed by enter)
214 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
218 <li>Editing the system wide configuration
</li>
221 You must activate debugfs and specify a mount point. This is typically done in
222 fstab such that it happens at boot time. If you have never used DebugFS before,
223 these operation would do this for you :
227 cp /etc/fstab /etc/fstab.lttng.bkp
228 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
232 then, rebooting or issuing the following command will activate debugfs :
238 You need to load the LTT modules to be able to control tracing from user
239 space. This is done by issuing the following commands. Note however
240 these commands load all LTT modules. Depending on what options you chose to
241 compile statically, you may not need to issue all these commands.
244 modprobe ltt-trace-control
245 modprobe ltt-marker-control
247 modprobe ltt-serialize
250 modprobe kernel-trace
256 modprobe syscall-trace
258 #if locking tracing is wanted, uncomment the following
259 #modprobe lockdep-trace
263 If you want to have complete information about the kernel state (including all
264 the process names), you need to load the ltt-statedump module. This is done by
265 issuing the command :
268 modprobe ltt-statedump
271 You can automate at boot time loading the ltt-control module by :
274 cp /etc/modules /etc/modules.bkp
275 echo ltt-trace-control
>> /etc/modules
276 echo ltt-marker-control
>> /etc/modules
277 echo ltt-tracer
>> /etc/modules
278 echo ltt-serialize
>> /etc/modules
279 echo ltt-relay
>> /etc/modules
280 echo ipc-trace
>> /etc/modules
281 echo kernel-trace
>> /etc/modules
282 echo mm-trace
>> /etc/modules
283 echo net-trace
>> /etc/modules
284 echo fs-trace
>> /etc/modules
285 echo jbd2-trace
>> /etc/modules
286 echo ext4-trace
>> /etc/modules
287 echo syscall-trace
>> /etc/modules
288 echo trap-trace
>> /etc/modules
289 #if locking tracing is wanted, uncomment the following
290 #echo lockdep-trace
>> /etc/modules
293 <li>Getting and installing the ltt-control package (on the traced machine)
</li>
295 (note : the ltt-control package contains lttd and lttctl. Although it has the
296 same name as the ltt-control kernel module, they are *not* the same thing.)
301 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
302 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
303 cd ltt-control-
0.x-xxxx2006
304 (refer to README to see the development libraries that must be installed on you
311 <li>Userspace tracing
</li>
314 Make sure you selected the kernel menuconfig option :
315 <M> or <*
> Support logging events from userspace
316 And that the ltt-userspace-event kernel module is loaded if selected as a
319 Simple userspace tracing is available through
320 echo
"some text to record" > /mnt/debugfs/ltt/write_event
322 It will appear in the trace under event :
327 <li>Getting and installing the LTTV package (on the visualisation machine, same
328 or different from the visualisation machine)
</li>
333 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
334 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
335 cd lttv-
0.x.xx-xxxx2008
336 (refer to README to see the development libraries that must be installed on your
343 <li>Getting and installing the markers-userspace package for user space
344 tracing (experimental)
</li>
347 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
352 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
354 <li>IMPORTANT : Arm Linux Kernel Markers after each boot
</li>
359 <li>Use graphical LTTV to control tracing and analyse traces
</li>
361 lttv-gui (or /usr/local/bin/lttv-gui)
362 - Spot the
"Tracing Control" icon : click on it
363 (it's a traffic light icon)
364 - enter the root password
368 * You should now see a trace
371 <li>Use text mode LTTng to control tracing
</li>
373 The tracing can be controlled from a terminal by using the lttctl command (as
378 lttctl -C -w /tmp/trace1 trace1
380 Stop tracing and destroy trace channels :
384 see lttctl --help for details.
387 (note : to see if the buffers has been filled, look at the dmesg output after
388 lttctl -R or after stopping tracing from the GUI, it will show an event lost
389 count. If it is the case, try using larger buffers. See lttctl --help to learn
390 how. lttv now also shows event lost messages in the console when loading a trace
391 with missing events or lost subbuffers.)
393 <li>Use text mode LTTV
</li>
395 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
396 graphical plugins available.
398 For example, a simple trace dump in text format is available with :
400 lttv -m textDump -t /tmp/trace
403 See lttv -m textDump --help for detailed command line options of textDump.
405 It is, in the current state of the project, very useful to use
"grep" on the
406 text output to filter by specific event fields. You can later copy the timestamp
407 of the events to the clipboard and paste them in the GUI by clicking on the
408 bottom right label
"Current time". Support for this type of filtering should
409 be added to the filter module soon.
413 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
414 hybrid. It can be especially useful when studying big workloads on a long period
417 When using this mode, the most important, low rate control information will be
418 recorded during all the trace by lttd (i.e. process creation/exit). The high
419 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
420 flight recorder buffer (now named flight-channelname_X).
422 The following lttctl commands take an hybrid trace :
424 Create trace channel, start lttd on normal channels, start tracing:
426 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
429 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
431 lttctl -D -w /tmp/trace2 trace2
434 Each
"overwrite" channel is flight recorder channel.
436 <li>Flight recorder mode
</li>
438 The flight recorder mode writes data into overwritten buffers for all channels,
439 including control channels, except for the facilities tracefiles. It consists of
440 setting all channels to
"overwrite".
442 The following lttctl commands take a flight recorder trace :
444 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
446 lttctl -D -w /tmp/trace3 trace3
452 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
457 See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
460 <li>Add new events to userspace programs with
461 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a></li>
464 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
465 allows inserting markers in executables and libraries, currently only on x86_32
470 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
473 <li>Create custom LTTV Debian packages
</li>
476 Use : dpkg-buildpackage -rfakeroot
479 You should then have your LTTV .deb files created for your architecture.
481 <li>Create custom LTTng packages
</li>
483 For building LTTng Debian packages :
484 get the build tree with patches applies as explained in section
2.
487 make menuconfig (or xconfig or config) (customize your configuration)
488 make-kpkg kernel_image
491 You will then see your freshly created .deb in /usr/src. Install it with
493 dpkg -i /usr/src/(image-name).deb
496 Then, follow the section
"Editing the system wide configuration" in section
2.