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=
"#licenses" name=
"TOClicenses">Licenses
</a></li>
21 <li><a href=
"#arch" name=
"TOCarch">Supported architectures
</a></li>
24 <li><a href=
"#section1" name=
"TOCsection1">Installing LTTng and LTTV from
27 <li><a href=
"#prerequisites" name=
"TOCprerequisites">Prerequisistes
</li>
28 <li><a href=
"#getlttng" name=
"TOCgetlttng">Getting the LTTng packages
</li>
29 <li><a href=
"#getlttngsrc" name=
"TOCgetlttngsrc">Getting the LTTng kernel sources
</li>
30 <li><a href=
"#installlttng" name=
"TOCinstalllttng">Installing a LTTng kernel
</li>
31 <li><a href=
"#editconfig" name=
"TOCeditconfig">Editing the system wide
33 <li><a href=
"#getlttctl" name=
"TOCgetlttctl">Getting and installing the
34 ltt-control package
</li>
35 <li><a href=
"#userspacetracing" name=
"TOCuserspacetracing">Userspace Tracing
</li>
36 <li><a href=
"#getlttv" name=
"TOCgetlttv">Getting and installing the LTTV package
</ul>
38 <li><a href=
"#section2" name=
"TOCsection2">Using LTTng and LTTV
</a></li>
40 <li><a href=
"#uselttvgui" name=
"TOCuselttvgui">Use graphical LTTV to control
41 tracing and analyse traces
</a></li>
42 <li><a href=
"#uselttngtext" name=
"TOCuselttngtext">Use text mode LTTng to
43 control tracing
</a></li>
44 <li><a href=
"#uselttvtext" name=
"TOCuselttvtext">Use text mode LTTV
</a></li>
45 <li><a href=
"#hybrid" name=
"TOChybrid">Tracing in
"Hybrid" mode
</a></li>
46 <li><a href=
"#flight" name=
"TOCflight">Tracing in flight recorder mode
</a></li>
49 <li><a href=
"#section3" name=
"TOCsection3">Adding kernel and user-space
52 <li><a href=
"#kerneltp" name=
"TOCkerneltp">Adding kernel instrumentation
</a></li>
53 <li><a href=
"#usertp" name=
"TOCusertp">Adding userspace instrumentation
</a></li>
56 <li><a href=
"#section4" name=
"TOCsection4">Creating Debian and RPM packages
59 <li><a href=
"#pkgdebian" name=
"TOCpkgdebian">Create custom LTTV Debian
60 <li><a href=
"#pkglttng" name=
"TOCpkglttng">Create custom LTTng packages
</a></li>
67 <h2><a href=
"#TOCintro" name=
"intro">Introduction
</a></h2>
69 This document is made of five parts : the first one explains how
70 to install LTTng and LTTV from sources, the second one describes the steps
71 to follow to trace a system and view it. The third part explains
72 briefly how to add a new trace point to the kernel and to user space
73 applications. The fourth and last part explains how to create Debian or RPM
74 packages from the LTTng and LTTV sources.
76 These operations are made for installing the LTTng
0.86 tracer on a linux
2.6.X
77 kernel. You will also find instructions for installation of LTTV
0.12.x : the
78 Linux Trace Toolkit Viewer.
79 To see the list of compatibilities between LTTng, ltt-control, LTTV, please
82 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility
</a>
84 The ongoing work had the Linux Kernel Markers integrated in the mainline Linux
85 kernel since Linux
2.6.24 and the Tracepoints since
2.6.28. In its current
86 state, the lttng patchset is necessary to have the trace clocksource, the
87 instrumentation and the LTTng high-speed data extraction mechanism added to the
92 <h3><a href=
"#TOClicenses" name=
"licenses">Licenses
</a></h3>
95 LTTng, UST and LTTV are developed by an open community. LTTng is released under
96 a dual Gnu LGPLv2.1/GPLv2 license, except for very few kernel-specific files
97 which are derived work from the Linux kernel.
99 LTTV is available under the Gnu GPLv2. The low-level LTTV trace reading library
100 is released under Gnu LGPLv2.1.
102 The UST (Userspace Tracing) and the Userspace RCU libraries are released under
103 the LGPLv2.1 license, which allows linking with non-GPL (BSD, proprietary...)
104 applications. The associated headers are released under MIT-style/BSD-style
107 Please refer to each particular file licensing for details.
111 <h3><a href=
"#TOCarch" name=
"arch">Supported architectures
</a></h3>
116 <li> PowerPC
32 and
64 bits
118 <li> Other ARM (with limited timestamping precision, e.g.
1HZ. Need
119 architecture-specific support for better precision)
121 <li> sh (partial architecture-specific instrumentation)
122 <li> sparc64 (partial architecture-specific instrumentation)
123 <li> s390 (partial architecture-specific instrumentation)
124 <li> Other architectures supported without architecture-specific instrumentation
125 and with low-resolution timestamps.
<br>
130 <li> Intel
32/
64 bits
131 <li> PowerPC
32 and
64 bits
132 <li> Possibly others. Takes care of endianness and type size difference between
133 the LTTng traces and the LTTV analysis tool.
138 <h2><a href=
"#TOCsection1" name=
"section1">Installation from sources
</a></h2>
141 <h3><a href=
"#TOCprerequisites" name=
"prerequisites">Prerequisites
</a></h3>
144 Tools needed to follow the package download steps :
152 You have to install the standard development libraries and programs necessary
153 to compile a kernel :
156 (from Documentation/Changes in the Linux kernel tree)
157 Gnu C
2.95.3 # gcc --version
158 Gnu make
3.79.1 # make --version
159 binutils
2.12 # ld -v
160 util-linux
2.10o # fdformat --version
161 module-init-tools
0.9.10 # depmod -V
165 You might also want to have libncurses5 to have the text mode kernel
166 configuration menu, but there are alternatives.
169 Prerequisites for LTTV
0.x.x installation are :
173 gtk
2.4 or better development libraries
174 (Debian : libgtk2.0, libgtk2.0-dev)
175 (Fedora : gtk2, gtk2-devel)
176 note : For Fedora users : this might require at least core
3 from Fedora,
177 or you might have to compile your own GTK2 library.
178 glib
2.4 or better development libraries
179 (Debian : libglib2.0-
0, libglib2.0-dev)
180 (Fedora : glib2, glib2-devel)
181 libpopt development libraries
182 (Debian : libpopt0, libpopt-dev)
184 libpango development libraries
185 (Debian : libpango1.0, libpango1.0-dev)
186 (Fedora : pango, pango-devel)
187 libc6 development librairies
188 (Debian : libc6, libc6-dev)
189 (Fedora : glibc, glibc)
196 See the list of compatibilities between LTTng, ltt-control and LTTV at :
198 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
199 versions compatibility
</a>.
202 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
208 (see http://ltt.polymtl.ca/lttng for package listing)
209 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
210 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
214 <h3><a href=
"#TOCgetlttngsrc" name=
"getlttngsrc">Getting LTTng kernel sources
</a></h3>
219 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
220 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
222 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
223 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
226 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
230 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing a LTTng kernel
</a></h3>
234 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
235 make menuconfig (or make xconfig or make config)
236 Select the < Help
> button if you are not familiar with kernel
238 Items preceded by [*] means they has to be built into the kernel.
239 Items preceded by [M] means they has to be built as modules.
240 Items preceded by [ ] means they should be removed.
241 go to the
"General setup" section
242 Select the following options :
243 [*] Prompt for development and/or incomplete code/drivers
245 [*] Activate userspace markers ABI (experimental, optional)
246 [*] Immediate value optimization (optional)
247 [*] Linux Trace Toolkit Next Generation (LTTng) --->
248 <M> or <*
> Compile lttng tracing probes
249 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
250 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
251 <M> or <*
> Linux Trace Toolkit Serializer
252 <M> or <*
> Linux Trace Toolkit Marker Control
253 <M> or <*
> Linux Trace Toolkit Tracer
254 [*] Align Linux Trace Toolkit Traces
255 <M> or <*
> Support logging events from userspace
256 [*] Support trace extraction from crash dump
257 <M> or <*
> Linux Trace Toolkit Trace Controller
258 <M> or <*
> Linux Trace Toolkit State Dump
264 (if necessary, create a initrd with mkinitrd or your preferate alternative)
265 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
270 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
273 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
274 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
275 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
276 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
277 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
278 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
279 that comes first is the default kernel)
281 select the right entry at the yaboot prompt (see choices : tab, select : type
282 the kernel name followed by enter)
283 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
287 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
288 configuration
</a></h3>
291 You must activate debugfs and specify a mount point. This is typically done in
292 fstab such that it happens at boot time. If you have never used DebugFS before,
293 these operation would do this for you :
297 cp /etc/fstab /etc/fstab.lttng.bkp
298 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
302 then, rebooting or issuing the following command will activate debugfs :
308 You need to load the LTT modules to be able to control tracing from user
309 space. This is done by issuing the following commands. Note however
310 these commands load all LTT modules. Depending on what options you chose to
311 compile statically, you may not need to issue all these commands.
314 modprobe ltt-trace-control
315 modprobe ltt-marker-control
317 modprobe ltt-serialize
320 modprobe kernel-trace
326 modprobe syscall-trace
328 #if locking tracing is wanted, uncomment the following
329 #modprobe lockdep-trace
333 If you want to have complete information about the kernel state (including all
334 the process names), you need to load the ltt-statedump module. This is done by
335 issuing the command :
338 modprobe ltt-statedump
341 You can automate at boot time loading the ltt-control module by :
344 cp /etc/modules /etc/modules.bkp
345 echo ltt-trace-control
>> /etc/modules
346 echo ltt-marker-control
>> /etc/modules
347 echo ltt-tracer
>> /etc/modules
348 echo ltt-serialize
>> /etc/modules
349 echo ltt-relay
>> /etc/modules
350 echo ipc-trace
>> /etc/modules
351 echo kernel-trace
>> /etc/modules
352 echo mm-trace
>> /etc/modules
353 echo net-trace
>> /etc/modules
354 echo fs-trace
>> /etc/modules
355 echo jbd2-trace
>> /etc/modules
356 echo ext4-trace
>> /etc/modules
357 echo syscall-trace
>> /etc/modules
358 echo trap-trace
>> /etc/modules
359 #if locking tracing is wanted, uncomment the following
360 #echo lockdep-trace
>> /etc/modules
364 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
365 ltt-control package (on the traced machine)
</a></h3>
367 (note : the ltt-control package contains lttd and lttctl. Although it has the
368 same name as the ltt-control kernel module, they are *not* the same thing.)
373 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
374 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
375 cd ltt-control-
0.x-xxxx2006
376 (refer to README to see the development libraries that must be installed on you
381 # (run ldconfig to ensure new shared objects are taken into account)
385 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
388 Make sure you selected the kernel menuconfig option :
389 <M> or <*
> Support logging events from userspace
390 And that the ltt-userspace-event kernel module is loaded if selected as a
393 Simple userspace tracing is available through
394 echo
"some text to record" > /mnt/debugfs/ltt/write_event
396 It will appear in the trace under event :
401 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
402 (on the visualisation machine, same
403 or different from the visualisation machine)
</a></h3>
408 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
409 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
410 cd lttv-
0.x.xx-xxxx2008
411 (refer to README to see the development libraries that must be installed on your
416 # (run ldconfig to ensure new shared objects are taken into account)
423 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
425 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
430 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
431 tracing and analyse traces
</a></h3>
433 lttv-gui (or /usr/local/bin/lttv-gui)
434 - Spot the
"Tracing Control" icon : click on it
435 (it's a traffic light icon)
436 - enter the root password
440 * You should now see a trace
443 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
445 The tracing can be controlled from a terminal by using the lttctl command (as
450 lttctl -C -w /tmp/trace1 trace1
452 Stop tracing and destroy trace channels :
456 see lttctl --help for details.
459 (note : to see if the buffers has been filled, look at the dmesg output after
460 lttctl -D or after stopping tracing from the GUI, it will show an event lost
461 count. If it is the case, try using larger buffers. See lttctl --help to learn
462 how. lttv now also shows event lost messages in the console when loading a trace
463 with missing events or lost subbuffers.)
465 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
467 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
468 graphical plugins available.
470 For example, a simple trace dump in text format is available with :
472 lttv -m textDump -t /tmp/trace
475 See lttv -m textDump --help for detailed command line options of textDump.
477 It is, in the current state of the project, very useful to use
"grep" on the
478 text output to filter by specific event fields. You can later copy the timestamp
479 of the events to the clipboard and paste them in the GUI by clicking on the
480 bottom right label
"Current time". Support for this type of filtering should
481 be added to the filter module soon.
483 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
485 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
486 hybrid. It can be especially useful when studying big workloads on a long period
489 When using this mode, the most important, low rate control information will be
490 recorded during all the trace by lttd (i.e. process creation/exit). The high
491 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
492 flight recorder buffer (now named flight-channelname_X).
494 The following lttctl commands take an hybrid trace :
496 Create trace channel, start lttd on normal channels, start tracing:
498 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
501 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
503 lttctl -D -w /tmp/trace2 trace2
506 Each
"overwrite" channel is flight recorder channel.
509 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
510 <li>Flight recorder mode
</li>
512 The flight recorder mode writes data into overwritten buffers for all channels,
513 including control channels, except for the facilities tracefiles. It consists of
514 setting all channels to
"overwrite".
516 The following lttctl commands take a flight recorder trace :
518 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
520 lttctl -D -w /tmp/trace3 trace3
526 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
530 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
531 instrumentation
</a></h3>
535 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>
537 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=blob;f=Documentation/trace/tracepoints.txt">Documentation/trace/tracepoints.txt
</a> in your kernel
541 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
542 for LTTng probe examples.
544 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
546 Add new events to userspace programs with
547 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a>.
548 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
549 allows inserting markers in executables and libraries, currently only on x86_32
552 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
555 Note that a new design document for a
3rd generation of tracepoint/marker-based
556 userspace tracing is available at
<a
557 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
558 Design
</a>. This new infrastructure is not yet implemented.
561 The easy quick-and-dirty way to perform userspace tracing is currently to write
562 an string to /mnt/debugfs/ltt/write_event. See
<a
563 href=
"#userspacetracing">Userspace tracing
</a> in the
564 installation for sources section of this document.
568 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
571 <h3><a href=
"#TOCpkgdebian" name=
"pkgdebian">Create custom LTTV Debian packages
</a></h3>
574 Use : dpkg-buildpackage -rfakeroot
577 You should then have your LTTV .deb files created for your architecture.
579 <h3><a href=
"#TOCpkglttng" name=
"pkglttng">Create custom LTTng packages
</a></h3>
581 For building LTTng Debian packages :
582 get the build tree with patches applies as explained in section
2.
585 make menuconfig (or xconfig or config) (customize your configuration)
586 make-kpkg kernel_image
589 You will then see your freshly created .deb in /usr/src. Install it with
591 dpkg -i /usr/src/(image-name).deb
594 Then, follow the section
"Editing the system wide configuration" in section
2.