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
30,
2010<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>
94 LTTng, UST and LTTV are developed by an open community. LTTng is released under
95 a dual Gnu LGPLv2.1/GPLv2 license, except for very few kernel-specific files
96 which are derived work from the Linux kernel.
98 LTTV is available under the Gnu GPLv2. The low-level LTTV trace reading library
99 is released under Gnu LGPLv2.1.
101 The UST (Userspace Tracing) and the Userspace RCU libraries are released under
102 the LGPLv2.1 license, which allows linking with non-GPL (BSD, proprietary...)
103 applications. The associated headers are released under MIT-style/BSD-style
106 Please refer to each particular file licensing for details.
108 <h3><a href=
"#TOCarch" name=
"arch">Supported architectures
</a></h3>
112 <li> PowerPC
32 and
64 bits
114 <li> Other ARM (with limited timestamping precision, e.g.
1HZ. Need
115 architecture-specific support for better precision)
117 <li> sh (partial architecture-specific instrumentation)
118 <li> sparc64 (partial architecture-specific instrumentation)
119 <li> s390 (partial architecture-specific instrumentation)
120 <li> Other architectures supported without architecture-specific instrumentation
121 and with low-resolution timestamps.
<br>
126 <li> Intel
32/
64 bits
127 <li> PowerPC
32 and
64 bits
128 <li> Possibly others. Takes care of endianness and type size difference between
129 the LTTng traces and the LTTV analysis tool.
134 <h2><a href=
"#TOCsection1" name=
"section1">Installation from sources
</a></h2>
137 <h3><a href=
"#TOCprerequisites" name=
"prerequisites">Prerequisites
</a></h3>
140 Tools needed to follow the package download steps :
148 You have to install the standard development libraries and programs necessary
149 to compile a kernel :
152 (from Documentation/Changes in the Linux kernel tree)
153 Gnu C
2.95.3 # gcc --version
154 Gnu make
3.79.1 # make --version
155 binutils
2.12 # ld -v
156 util-linux
2.10o # fdformat --version
157 module-init-tools
0.9.10 # depmod -V
161 You might also want to have libncurses5 to have the text mode kernel
162 configuration menu, but there are alternatives.
165 Prerequisites for LTTV
0.x.x installation are :
169 gtk
2.4 or better development libraries
170 (Debian : libgtk2.0, libgtk2.0-dev)
171 (Fedora : gtk2, gtk2-devel)
172 note : For Fedora users : this might require at least core
3 from Fedora,
173 or you might have to compile your own GTK2 library.
174 glib
2.4 or better development libraries
175 (Debian : libglib2.0-
0, libglib2.0-dev)
176 (Fedora : glib2, glib2-devel)
177 libpopt development libraries
178 (Debian : libpopt0, libpopt-dev)
180 libpango development libraries
181 (Debian : libpango1.0, libpango1.0-dev)
182 (Fedora : pango, pango-devel)
183 libc6 development librairies
184 (Debian : libc6, libc6-dev)
185 (Fedora : glibc, glibc)
192 See the list of compatibilities between LTTng, ltt-control and LTTV at :
194 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
195 versions compatibility
</a>.
198 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
204 (see http://ltt.polymtl.ca/lttng for package listing)
205 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
206 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
210 <h3><a href=
"#TOCgetlttngsrc" name=
"getlttngsrc">Getting LTTng kernel sources
</a></h3>
215 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
216 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
218 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
219 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
222 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
226 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing a LTTng kernel
</a></h3>
230 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
231 make menuconfig (or make xconfig or make config)
232 Select the < Help
> button if you are not familiar with kernel
234 Items preceded by [*] means they has to be built into the kernel.
235 Items preceded by [M] means they has to be built as modules.
236 Items preceded by [ ] means they should be removed.
237 go to the
"General setup" section
238 Select the following options :
239 [*] Prompt for development and/or incomplete code/drivers
241 [*] Activate userspace markers ABI (experimental, optional)
242 [*] Immediate value optimization (optional)
243 [*] Linux Trace Toolkit Next Generation (LTTng) --->
244 <M> or <*
> Compile lttng tracing probes
245 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
246 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
247 <M> or <*
> Linux Trace Toolkit Serializer
248 <M> or <*
> Linux Trace Toolkit Marker Control
249 <M> or <*
> Linux Trace Toolkit Tracer
250 [*] Align Linux Trace Toolkit Traces
251 <M> or <*
> Support logging events from userspace
252 [*] Support trace extraction from crash dump
253 <M> or <*
> Linux Trace Toolkit Trace Controller
254 <M> or <*
> Linux Trace Toolkit State Dump
260 (if necessary, create a initrd with mkinitrd or your preferate alternative)
261 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
266 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
269 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
270 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
271 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
272 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
273 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
274 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
275 that comes first is the default kernel)
277 select the right entry at the yaboot prompt (see choices : tab, select : type
278 the kernel name followed by enter)
279 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
283 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
284 configuration
</a></h3>
287 You must activate debugfs and specify a mount point. This is typically done in
288 fstab such that it happens at boot time. If you have never used DebugFS before,
289 these operation would do this for you :
293 cp /etc/fstab /etc/fstab.lttng.bkp
294 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
298 then, rebooting or issuing the following command will activate debugfs :
304 You need to load the LTT modules to be able to control tracing from user
305 space. This is done by issuing the following commands. Note however
306 these commands load all LTT modules. Depending on what options you chose to
307 compile statically, you may not need to issue all these commands.
310 modprobe ltt-trace-control
311 modprobe ltt-marker-control
313 modprobe ltt-serialize
316 modprobe kernel-trace
322 modprobe syscall-trace
324 #if locking tracing is wanted, uncomment the following
325 #modprobe lockdep-trace
329 If you want to have complete information about the kernel state (including all
330 the process names), you need to load the ltt-statedump module. This is done by
331 issuing the command :
334 modprobe ltt-statedump
337 You can automate at boot time loading the ltt-control module by :
340 cp /etc/modules /etc/modules.bkp
341 echo ltt-trace-control
>> /etc/modules
342 echo ltt-marker-control
>> /etc/modules
343 echo ltt-tracer
>> /etc/modules
344 echo ltt-serialize
>> /etc/modules
345 echo ltt-relay
>> /etc/modules
346 echo ipc-trace
>> /etc/modules
347 echo kernel-trace
>> /etc/modules
348 echo mm-trace
>> /etc/modules
349 echo net-trace
>> /etc/modules
350 echo fs-trace
>> /etc/modules
351 echo jbd2-trace
>> /etc/modules
352 echo ext4-trace
>> /etc/modules
353 echo syscall-trace
>> /etc/modules
354 echo trap-trace
>> /etc/modules
355 #if locking tracing is wanted, uncomment the following
356 #echo lockdep-trace
>> /etc/modules
360 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
361 ltt-control package (on the traced machine)
</a></h3>
363 (note : the ltt-control package contains lttd and lttctl. Although it has the
364 same name as the ltt-control kernel module, they are *not* the same thing.)
369 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
370 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
371 cd ltt-control-
0.x-xxxx2006
372 (refer to README to see the development libraries that must be installed on you
377 # (run ldconfig to ensure new shared objects are taken into account)
381 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
384 Make sure you selected the kernel menuconfig option :
385 <M> or <*
> Support logging events from userspace
386 And that the ltt-userspace-event kernel module is loaded if selected as a
389 Simple userspace tracing is available through
390 echo
"some text to record" > /mnt/debugfs/ltt/write_event
392 It will appear in the trace under event :
397 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
398 (on the visualisation machine, same
399 or different from the visualisation machine)
</a></h3>
404 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
405 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
406 cd lttv-
0.x.xx-xxxx2008
407 (refer to README to see the development libraries that must be installed on your
412 # (run ldconfig to ensure new shared objects are taken into account)
419 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
421 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
426 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
427 tracing and analyse traces
</a></h3>
429 lttv-gui (or /usr/local/bin/lttv-gui)
430 - Spot the
"Tracing Control" icon : click on it
431 (it's a traffic light icon)
432 - enter the root password
436 * You should now see a trace
439 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
441 The tracing can be controlled from a terminal by using the lttctl command (as
446 lttctl -C -w /tmp/trace1 trace1
448 Stop tracing and destroy trace channels :
452 see lttctl --help for details.
455 (note : to see if the buffers has been filled, look at the dmesg output after
456 lttctl -D or after stopping tracing from the GUI, it will show an event lost
457 count. If it is the case, try using larger buffers. See lttctl --help to learn
458 how. lttv now also shows event lost messages in the console when loading a trace
459 with missing events or lost subbuffers.)
461 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
463 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
464 graphical plugins available.
466 For example, a simple trace dump in text format is available with :
468 lttv -m textDump -t /tmp/trace
471 See lttv -m textDump --help for detailed command line options of textDump.
473 It is, in the current state of the project, very useful to use
"grep" on the
474 text output to filter by specific event fields. You can later copy the timestamp
475 of the events to the clipboard and paste them in the GUI by clicking on the
476 bottom right label
"Current time". Support for this type of filtering should
477 be added to the filter module soon.
479 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
481 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
482 hybrid. It can be especially useful when studying big workloads on a long period
485 When using this mode, the most important, low rate control information will be
486 recorded during all the trace by lttd (i.e. process creation/exit). The high
487 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
488 flight recorder buffer (now named flight-channelname_X).
490 The following lttctl commands take an hybrid trace :
492 Create trace channel, start lttd on normal channels, start tracing:
494 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
497 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
499 lttctl -D -w /tmp/trace2 trace2
502 Each
"overwrite" channel is flight recorder channel.
505 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
506 <li>Flight recorder mode
</li>
508 The flight recorder mode writes data into overwritten buffers for all channels,
509 including control channels, except for the facilities tracefiles. It consists of
510 setting all channels to
"overwrite".
512 The following lttctl commands take a flight recorder trace :
514 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
516 lttctl -D -w /tmp/trace3 trace3
522 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
526 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
527 instrumentation
</a></h3>
531 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>
533 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
537 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
538 for LTTng probe examples.
540 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
542 Add new events to userspace programs with
543 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a>.
544 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
545 allows inserting markers in executables and libraries, currently only on x86_32
548 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
551 Note that a new design document for a
3rd generation of tracepoint/marker-based
552 userspace tracing is available at
<a
553 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
554 Design
</a>. This new infrastructure is not yet implemented.
557 The easy quick-and-dirty way to perform userspace tracing is currently to write
558 an string to /mnt/debugfs/ltt/write_event. See
<a
559 href=
"#userspacetracing">Userspace tracing
</a> in the
560 installation for sources section of this document.
564 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
567 <h3><a href=
"#TOCpkgdebian" name=
"pkgdebian">Create custom LTTV Debian packages
</a></h3>
570 Use : dpkg-buildpackage -rfakeroot
573 You should then have your LTTV .deb files created for your architecture.
575 <h3><a href=
"#TOCpkglttng" name=
"pkglttng">Create custom LTTng packages
</a></h3>
577 For building LTTng Debian packages :
578 get the build tree with patches applies as explained in section
2.
581 make menuconfig (or xconfig or config) (customize your configuration)
582 make-kpkg kernel_image
585 You will then see your freshly created .deb in /usr/src. Install it with
587 dpkg -i /usr/src/(image-name).deb
590 Then, follow the section
"Editing the system wide configuration" in section
2.