1 <!DOCTYPE html PUBLIC
"-//W3C//DTD HTML 4.01 Transitional//EN">
4 <title>Linux Trace Toolkit Next Generation Manual
</title>
8 <h1>Linux Trace Toolkit Next Generation Manual
</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>
19 <li><a href=
"#arch" name=
"TOCarch">Supported architectures
</a></li>
22 <li><a href=
"#section1" name=
"TOCsection1">Installing LTTng and LTTV from
25 <li><a href=
"#prerequisites" name=
"TOCprerequisites">Prerequisistes
</li>
26 <li><a href=
"#getlttng" name=
"TOCgetlttng">Getting the LTTng packages
</li>
27 <li><a href=
"#getlttngsrc" name=
"TOCgetlttngsrc">Getting the LTTng kernel sources
</li>
28 <li><a href=
"#installlttng" name=
"TOCinstalllttng">Installing a LTTng kernel
</li>
29 <li><a href=
"#editconfig" name=
"TOCeditconfig">Editing the system wide
31 <li><a href=
"#getlttctl" name=
"TOCgetlttctl">Getting and installing the
32 ltt-control package
</li>
33 <li><a href=
"#userspacetracing" name=
"TOCuserspacetracing">Userspace Tracing
</li>
34 <li><a href=
"#getlttv" name=
"TOCgetlttv">Getting and installing the LTTV package
</ul>
36 <li><a href=
"#section2" name=
"TOCsection2">Using LTTng and LTTV
</a></li>
38 <li><a href=
"#uselttvgui" name=
"TOCuselttvgui">Use graphical LTTV to control
39 tracing and analyse traces
</a></li>
40 <li><a href=
"#uselttngtext" name=
"TOCuselttngtext">Use text mode LTTng to
41 control tracing
</a></li>
42 <li><a href=
"#uselttvtext" name=
"TOCuselttvtext">Use text mode LTTV
</a></li>
43 <li><a href=
"#hybrid" name=
"TOChybrid">Tracing in
"Hybrid" mode
</a></li>
44 <li><a href=
"#flight" name=
"TOCflight">Tracing in flight recorder mode
</a></li>
47 <li><a href=
"#section3" name=
"TOCsection3">Adding kernel and user-space
50 <li><a href=
"#kerneltp" name=
"TOCkerneltp">Adding kernel instrumentation
</a></li>
51 <li><a href=
"#usertp" name=
"TOCusertp">Adding userspace instrumentation
</a></li>
54 <li><a href=
"#section4" name=
"TOCsection4">Creating Debian and RPM packages
57 <li><a href=
"#pkgdebian" name=
"TOCpkgdebian">Create custom LTTV Debian
58 <li><a href=
"#pkglttng" name=
"TOCpkglttng">Create custom LTTng packages
</a></li>
65 <h2><a href=
"#TOCintro" name=
"intro">Introduction
</a></h2>
67 This document is made of five parts : the first one explains how
68 to install LTTng and LTTV from sources, the second one describes the steps
69 to follow to trace a system and view it. The third part explains
70 briefly how to add a new trace point to the kernel and to user space
71 applications. The fourth and last part explains how to create Debian or RPM
72 packages from the LTTng and LTTV sources.
74 These operations are made for installing the LTTng
0.86 tracer on a linux
2.6.X
75 kernel. You will also find instructions for installation of LTTV
0.12.x : the
76 Linux Trace Toolkit Viewer.
77 To see the list of compatibilities between LTTng, ltt-control, LTTV, please
80 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility
</a>
82 The ongoing work had the Linux Kernel Markers integrated in the mainline Linux
83 kernel since Linux
2.6.24 and the Tracepoints since
2.6.28. In its current
84 state, the lttng patchset is necessary to have the trace clocksource, the
85 instrumentation and the LTTng high-speed data extraction mechanism added to the
90 <h3><a href=
"#TOCarch" name=
"arch">Supported architectures
</a></h3>
95 <li> PowerPC
32 and
64 bits
97 <li> Other ARM (with limited timestamping precision, e.g.
1HZ. Need
98 architecture-specific support for better precision)
100 <li> sh (partial architecture-specific instrumentation)
101 <li> sparc64 (partial architecture-specific instrumentation)
102 <li> s390 (partial architecture-specific instrumentation)
103 <li> Other architectures supported without architecture-specific instrumentation
104 and with low-resolution timestamps.
<br>
109 <li> Intel
32/
64 bits
110 <li> PowerPC
32 and
64 bits
111 <li> Possibly others. Takes care of endianness and type size difference between
112 the LTTng traces and the LTTV analysis tool.
117 <h2><a href=
"#TOCsection1" name=
"section1">Installation from sources
</a></h2>
120 <h3><a href=
"#TOCprerequisites" name=
"prerequisites">Prerequisites
</a></h3>
123 Tools needed to follow the package download steps :
131 You have to install the standard development libraries and programs necessary
132 to compile a kernel :
135 (from Documentation/Changes in the Linux kernel tree)
136 Gnu C
2.95.3 # gcc --version
137 Gnu make
3.79.1 # make --version
138 binutils
2.12 # ld -v
139 util-linux
2.10o # fdformat --version
140 module-init-tools
0.9.10 # depmod -V
144 You might also want to have libncurses5 to have the text mode kernel
145 configuration menu, but there are alternatives.
148 Prerequisites for LTTV
0.x.x installation are :
152 gtk
2.4 or better development libraries
153 (Debian : libgtk2.0, libgtk2.0-dev)
154 (Fedora : gtk2, gtk2-devel)
155 note : For Fedora users : this might require at least core
3 from Fedora,
156 or you might have to compile your own GTK2 library.
157 glib
2.4 or better development libraries
158 (Debian : libglib2.0-
0, libglib2.0-dev)
159 (Fedora : glib2, glib2-devel)
160 libpopt development libraries
161 (Debian : libpopt0, libpopt-dev)
163 libpango development libraries
164 (Debian : libpango1.0, libpango1.0-dev)
165 (Fedora : pango, pango-devel)
166 libc6 development librairies
167 (Debian : libc6, libc6-dev)
168 (Fedora : glibc, glibc)
175 See the list of compatibilities between LTTng, ltt-control and LTTV at :
177 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
178 versions compatibility
</a>.
181 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
187 (see http://ltt.polymtl.ca/lttng for package listing)
188 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
189 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
193 <h3><a href=
"#TOCgetlttngsrc" name=
"getlttngsrc">Getting LTTng kernel sources
</a></h3>
198 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
199 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
201 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
202 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
205 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
209 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing a LTTng kernel
</a></h3>
213 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
214 make menuconfig (or make xconfig or make config)
215 Select the < Help
> button if you are not familiar with kernel
217 Items preceded by [*] means they has to be built into the kernel.
218 Items preceded by [M] means they has to be built as modules.
219 Items preceded by [ ] means they should be removed.
220 go to the
"General setup" section
221 Select the following options :
222 [*] Prompt for development and/or incomplete code/drivers
224 [*] Activate userspace markers ABI (experimental, optional)
225 [*] Immediate value optimization (optional)
226 [*] Linux Trace Toolkit Next Generation (LTTng) --->
227 <M> or <*
> Compile lttng tracing probes
228 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
229 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
230 <M> or <*
> Linux Trace Toolkit Serializer
231 <M> or <*
> Linux Trace Toolkit Marker Control
232 <M> or <*
> Linux Trace Toolkit Tracer
233 [*] Align Linux Trace Toolkit Traces
234 <M> or <*
> Support logging events from userspace
235 [*] Support trace extraction from crash dump
236 <M> or <*
> Linux Trace Toolkit Trace Controller
237 <M> or <*
> Linux Trace Toolkit State Dump
243 (if necessary, create a initrd with mkinitrd or your preferate alternative)
244 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
249 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
252 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
253 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
254 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
255 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
256 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
257 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
258 that comes first is the default kernel)
260 select the right entry at the yaboot prompt (see choices : tab, select : type
261 the kernel name followed by enter)
262 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
266 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
267 configuration
</a></h3>
270 You must activate debugfs and specify a mount point. This is typically done in
271 fstab such that it happens at boot time. If you have never used DebugFS before,
272 these operation would do this for you :
276 cp /etc/fstab /etc/fstab.lttng.bkp
277 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
281 then, rebooting or issuing the following command will activate debugfs :
287 You need to load the LTT modules to be able to control tracing from user
288 space. This is done by issuing the following commands. Note however
289 these commands load all LTT modules. Depending on what options you chose to
290 compile statically, you may not need to issue all these commands.
293 modprobe ltt-trace-control
294 modprobe ltt-marker-control
296 modprobe ltt-serialize
299 modprobe kernel-trace
305 modprobe syscall-trace
307 #if locking tracing is wanted, uncomment the following
308 #modprobe lockdep-trace
312 If you want to have complete information about the kernel state (including all
313 the process names), you need to load the ltt-statedump module. This is done by
314 issuing the command :
317 modprobe ltt-statedump
320 You can automate at boot time loading the ltt-control module by :
323 cp /etc/modules /etc/modules.bkp
324 echo ltt-trace-control
>> /etc/modules
325 echo ltt-marker-control
>> /etc/modules
326 echo ltt-tracer
>> /etc/modules
327 echo ltt-serialize
>> /etc/modules
328 echo ltt-relay
>> /etc/modules
329 echo ipc-trace
>> /etc/modules
330 echo kernel-trace
>> /etc/modules
331 echo mm-trace
>> /etc/modules
332 echo net-trace
>> /etc/modules
333 echo fs-trace
>> /etc/modules
334 echo jbd2-trace
>> /etc/modules
335 echo ext4-trace
>> /etc/modules
336 echo syscall-trace
>> /etc/modules
337 echo trap-trace
>> /etc/modules
338 #if locking tracing is wanted, uncomment the following
339 #echo lockdep-trace
>> /etc/modules
343 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
344 ltt-control package (on the traced machine)
</a></h3>
346 (note : the ltt-control package contains lttd and lttctl. Although it has the
347 same name as the ltt-control kernel module, they are *not* the same thing.)
352 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
353 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
354 cd ltt-control-
0.x-xxxx2006
355 (refer to README to see the development libraries that must be installed on you
362 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
365 Make sure you selected the kernel menuconfig option :
366 <M> or <*
> Support logging events from userspace
367 And that the ltt-userspace-event kernel module is loaded if selected as a
370 Simple userspace tracing is available through
371 echo
"some text to record" > /mnt/debugfs/ltt/write_event
373 It will appear in the trace under event :
378 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
379 (on the visualisation machine, same
380 or different from the visualisation machine)
</a></h3>
385 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
386 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
387 cd lttv-
0.x.xx-xxxx2008
388 (refer to README to see the development libraries that must be installed on your
398 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
400 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
405 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
406 tracing and analyse traces
</a></h3>
408 lttv-gui (or /usr/local/bin/lttv-gui)
409 - Spot the
"Tracing Control" icon : click on it
410 (it's a traffic light icon)
411 - enter the root password
415 * You should now see a trace
418 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
420 The tracing can be controlled from a terminal by using the lttctl command (as
425 lttctl -C -w /tmp/trace1 trace1
427 Stop tracing and destroy trace channels :
431 see lttctl --help for details.
434 (note : to see if the buffers has been filled, look at the dmesg output after
435 lttctl -D or after stopping tracing from the GUI, it will show an event lost
436 count. If it is the case, try using larger buffers. See lttctl --help to learn
437 how. lttv now also shows event lost messages in the console when loading a trace
438 with missing events or lost subbuffers.)
440 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
442 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
443 graphical plugins available.
445 For example, a simple trace dump in text format is available with :
447 lttv -m textDump -t /tmp/trace
450 See lttv -m textDump --help for detailed command line options of textDump.
452 It is, in the current state of the project, very useful to use
"grep" on the
453 text output to filter by specific event fields. You can later copy the timestamp
454 of the events to the clipboard and paste them in the GUI by clicking on the
455 bottom right label
"Current time". Support for this type of filtering should
456 be added to the filter module soon.
458 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
460 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
461 hybrid. It can be especially useful when studying big workloads on a long period
464 When using this mode, the most important, low rate control information will be
465 recorded during all the trace by lttd (i.e. process creation/exit). The high
466 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
467 flight recorder buffer (now named flight-channelname_X).
469 The following lttctl commands take an hybrid trace :
471 Create trace channel, start lttd on normal channels, start tracing:
473 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
476 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
478 lttctl -D -w /tmp/trace2 trace2
481 Each
"overwrite" channel is flight recorder channel.
484 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
485 <li>Flight recorder mode
</li>
487 The flight recorder mode writes data into overwritten buffers for all channels,
488 including control channels, except for the facilities tracefiles. It consists of
489 setting all channels to
"overwrite".
491 The following lttctl commands take a flight recorder trace :
493 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
495 lttctl -D -w /tmp/trace3 trace3
501 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
505 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
506 instrumentation
</a></h3>
510 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=blob;f=Documentation/markers.txt">Documentation/markers.txt
</a>
512 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=blob;f=Documentation/tracepoints.txt">Documentation/tracepoints.txt
</a> in your kernel
516 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
517 for LTTng probe examples.
519 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
521 Add new events to userspace programs with
522 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a>.
523 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
524 allows inserting markers in executables and libraries, currently only on x86_32
527 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
530 Note that a new design document for a
3rd generation of tracepoint/marker-based
531 userspace tracing is available at
<a
532 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
533 Design
</a>. This new infrastructure is not yet implemented.
536 The easy quick-and-dirty way to perform userspace tracing is currently to write
537 an string to /mnt/debugfs/ltt/write_event. See
<a
538 href=
"#userspacetracing">Userspace tracing
</a> in the
539 installation for sources section of this document.
543 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
546 <h3><a href=
"#TOCpkgdebian" name=
"pkgdebian">Create custom LTTV Debian packages
</a></h3>
549 Use : dpkg-buildpackage -rfakeroot
552 You should then have your LTTV .deb files created for your architecture.
554 <h3><a href=
"#TOCpkglttng" name=
"pkglttng">Create custom LTTng packages
</a></h3>
556 For building LTTng Debian packages :
557 get the build tree with patches applies as explained in section
2.
560 make menuconfig (or xconfig or config) (customize your configuration)
561 make-kpkg kernel_image
564 You will then see your freshly created .deb in /usr/src. Install it with
566 dpkg -i /usr/src/(image-name).deb
569 Then, follow the section
"Editing the system wide configuration" in section
2.