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=
"#TOClicense" name=
"license">Licenses
</a></h3>
93 LTTng, UST and LTTV are developed by an open community. LTTng is released under
94 a dual Gnu LGPLv2.1/GPLv2 license, except for very few kernel-specific files
95 which are derived work from the Linux kernel.
97 LTTV is available under the Gnu GPLv2. The low-level LTTV trace reading library
98 is released under Gnu LGPLv2.1.
100 The UST (Userspace Tracing) and the Userspace RCU libraries are released under
101 the LGPLv2.1 license, which allows linking with non-GPL (BSD, proprietary...)
102 applications. The associated headers are released under MIT-style/BSD-style
105 Please refer to each particular file licensing for details.
109 <h3><a href=
"#TOCarch" name=
"arch">Supported architectures
</a></h3>
114 <li> PowerPC
32 and
64 bits
116 <li> Other ARM (with limited timestamping precision, e.g.
1HZ. Need
117 architecture-specific support for better precision)
119 <li> sh (partial architecture-specific instrumentation)
120 <li> sparc64 (partial architecture-specific instrumentation)
121 <li> s390 (partial architecture-specific instrumentation)
122 <li> Other architectures supported without architecture-specific instrumentation
123 and with low-resolution timestamps.
<br>
128 <li> Intel
32/
64 bits
129 <li> PowerPC
32 and
64 bits
130 <li> Possibly others. Takes care of endianness and type size difference between
131 the LTTng traces and the LTTV analysis tool.
136 <h2><a href=
"#TOCsection1" name=
"section1">Installation from sources
</a></h2>
139 <h3><a href=
"#TOCprerequisites" name=
"prerequisites">Prerequisites
</a></h3>
142 Tools needed to follow the package download steps :
150 You have to install the standard development libraries and programs necessary
151 to compile a kernel :
154 (from Documentation/Changes in the Linux kernel tree)
155 Gnu C
2.95.3 # gcc --version
156 Gnu make
3.79.1 # make --version
157 binutils
2.12 # ld -v
158 util-linux
2.10o # fdformat --version
159 module-init-tools
0.9.10 # depmod -V
163 You might also want to have libncurses5 to have the text mode kernel
164 configuration menu, but there are alternatives.
167 Prerequisites for LTTV
0.x.x installation are :
171 gtk
2.4 or better development libraries
172 (Debian : libgtk2.0, libgtk2.0-dev)
173 (Fedora : gtk2, gtk2-devel)
174 note : For Fedora users : this might require at least core
3 from Fedora,
175 or you might have to compile your own GTK2 library.
176 glib
2.4 or better development libraries
177 (Debian : libglib2.0-
0, libglib2.0-dev)
178 (Fedora : glib2, glib2-devel)
179 libpopt development libraries
180 (Debian : libpopt0, libpopt-dev)
182 libpango development libraries
183 (Debian : libpango1.0, libpango1.0-dev)
184 (Fedora : pango, pango-devel)
185 libc6 development librairies
186 (Debian : libc6, libc6-dev)
187 (Fedora : glibc, glibc)
194 See the list of compatibilities between LTTng, ltt-control and LTTV at :
196 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
197 versions compatibility
</a>.
200 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
206 (see http://ltt.polymtl.ca/lttng for package listing)
207 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
208 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
212 <h3><a href=
"#TOCgetlttngsrc" name=
"getlttngsrc">Getting LTTng kernel sources
</a></h3>
217 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
218 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
220 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
221 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
224 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
228 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing a LTTng kernel
</a></h3>
232 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
233 make menuconfig (or make xconfig or make config)
234 Select the < Help
> button if you are not familiar with kernel
236 Items preceded by [*] means they has to be built into the kernel.
237 Items preceded by [M] means they has to be built as modules.
238 Items preceded by [ ] means they should be removed.
239 go to the
"General setup" section
240 Select the following options :
241 [*] Prompt for development and/or incomplete code/drivers
243 [*] Activate userspace markers ABI (experimental, optional)
244 [*] Immediate value optimization (optional)
245 [*] Linux Trace Toolkit Next Generation (LTTng) --->
246 <M> or <*
> Compile lttng tracing probes
247 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
248 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
249 <M> or <*
> Linux Trace Toolkit Serializer
250 <M> or <*
> Linux Trace Toolkit Marker Control
251 <M> or <*
> Linux Trace Toolkit Tracer
252 [*] Align Linux Trace Toolkit Traces
253 <M> or <*
> Support logging events from userspace
254 [*] Support trace extraction from crash dump
255 <M> or <*
> Linux Trace Toolkit Trace Controller
256 <M> or <*
> Linux Trace Toolkit State Dump
262 (if necessary, create a initrd with mkinitrd or your preferate alternative)
263 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
268 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
271 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
272 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
273 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
274 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
275 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
276 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
277 that comes first is the default kernel)
279 select the right entry at the yaboot prompt (see choices : tab, select : type
280 the kernel name followed by enter)
281 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
285 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
286 configuration
</a></h3>
289 You must activate debugfs and specify a mount point. This is typically done in
290 fstab such that it happens at boot time. If you have never used DebugFS before,
291 these operation would do this for you :
295 cp /etc/fstab /etc/fstab.lttng.bkp
296 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
300 then, rebooting or issuing the following command will activate debugfs :
306 You need to load the LTT modules to be able to control tracing from user
307 space. This is done by issuing the following commands. Note however
308 these commands load all LTT modules. Depending on what options you chose to
309 compile statically, you may not need to issue all these commands.
312 modprobe ltt-trace-control
313 modprobe ltt-marker-control
315 modprobe ltt-serialize
318 modprobe kernel-trace
324 modprobe syscall-trace
326 #if locking tracing is wanted, uncomment the following
327 #modprobe lockdep-trace
331 If you want to have complete information about the kernel state (including all
332 the process names), you need to load the ltt-statedump module. This is done by
333 issuing the command :
336 modprobe ltt-statedump
339 You can automate at boot time loading the ltt-control module by :
342 cp /etc/modules /etc/modules.bkp
343 echo ltt-trace-control
>> /etc/modules
344 echo ltt-marker-control
>> /etc/modules
345 echo ltt-tracer
>> /etc/modules
346 echo ltt-serialize
>> /etc/modules
347 echo ltt-relay
>> /etc/modules
348 echo ipc-trace
>> /etc/modules
349 echo kernel-trace
>> /etc/modules
350 echo mm-trace
>> /etc/modules
351 echo net-trace
>> /etc/modules
352 echo fs-trace
>> /etc/modules
353 echo jbd2-trace
>> /etc/modules
354 echo ext4-trace
>> /etc/modules
355 echo syscall-trace
>> /etc/modules
356 echo trap-trace
>> /etc/modules
357 #if locking tracing is wanted, uncomment the following
358 #echo lockdep-trace
>> /etc/modules
362 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
363 ltt-control package (on the traced machine)
</a></h3>
365 (note : the ltt-control package contains lttd and lttctl. Although it has the
366 same name as the ltt-control kernel module, they are *not* the same thing.)
371 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
372 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
373 cd ltt-control-
0.x-xxxx2006
374 (refer to README to see the development libraries that must be installed on you
379 # (run ldconfig to ensure new shared objects are taken into account)
383 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
386 Make sure you selected the kernel menuconfig option :
387 <M> or <*
> Support logging events from userspace
388 And that the ltt-userspace-event kernel module is loaded if selected as a
391 Simple userspace tracing is available through
392 echo
"some text to record" > /mnt/debugfs/ltt/write_event
394 It will appear in the trace under event :
399 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
400 (on the visualisation machine, same
401 or different from the visualisation machine)
</a></h3>
406 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
407 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
408 cd lttv-
0.x.xx-xxxx2008
409 (refer to README to see the development libraries that must be installed on your
414 # (run ldconfig to ensure new shared objects are taken into account)
421 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
423 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
428 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
429 tracing and analyse traces
</a></h3>
431 lttv-gui (or /usr/local/bin/lttv-gui)
432 - Spot the
"Tracing Control" icon : click on it
433 (it's a traffic light icon)
434 - enter the root password
438 * You should now see a trace
441 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
443 The tracing can be controlled from a terminal by using the lttctl command (as
448 lttctl -C -w /tmp/trace1 trace1
450 Stop tracing and destroy trace channels :
454 see lttctl --help for details.
457 (note : to see if the buffers has been filled, look at the dmesg output after
458 lttctl -D or after stopping tracing from the GUI, it will show an event lost
459 count. If it is the case, try using larger buffers. See lttctl --help to learn
460 how. lttv now also shows event lost messages in the console when loading a trace
461 with missing events or lost subbuffers.)
463 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
465 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
466 graphical plugins available.
468 For example, a simple trace dump in text format is available with :
470 lttv -m textDump -t /tmp/trace
473 See lttv -m textDump --help for detailed command line options of textDump.
475 It is, in the current state of the project, very useful to use
"grep" on the
476 text output to filter by specific event fields. You can later copy the timestamp
477 of the events to the clipboard and paste them in the GUI by clicking on the
478 bottom right label
"Current time". Support for this type of filtering should
479 be added to the filter module soon.
481 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
483 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
484 hybrid. It can be especially useful when studying big workloads on a long period
487 When using this mode, the most important, low rate control information will be
488 recorded during all the trace by lttd (i.e. process creation/exit). The high
489 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
490 flight recorder buffer (now named flight-channelname_X).
492 The following lttctl commands take an hybrid trace :
494 Create trace channel, start lttd on normal channels, start tracing:
496 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
499 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
501 lttctl -D -w /tmp/trace2 trace2
504 Each
"overwrite" channel is flight recorder channel.
507 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
508 <li>Flight recorder mode
</li>
510 The flight recorder mode writes data into overwritten buffers for all channels,
511 including control channels, except for the facilities tracefiles. It consists of
512 setting all channels to
"overwrite".
514 The following lttctl commands take a flight recorder trace :
516 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
518 lttctl -D -w /tmp/trace3 trace3
524 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
528 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
529 instrumentation
</a></h3>
533 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>
535 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
539 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
540 for LTTng probe examples.
542 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
544 Add new events to userspace programs with
545 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a>.
546 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
547 allows inserting markers in executables and libraries, currently only on x86_32
550 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
553 Note that a new design document for a
3rd generation of tracepoint/marker-based
554 userspace tracing is available at
<a
555 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
556 Design
</a>. This new infrastructure is not yet implemented.
559 The easy quick-and-dirty way to perform userspace tracing is currently to write
560 an string to /mnt/debugfs/ltt/write_event. See
<a
561 href=
"#userspacetracing">Userspace tracing
</a> in the
562 installation for sources section of this document.
566 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
569 <h3><a href=
"#TOCpkgdebian" name=
"pkgdebian">Create custom LTTV Debian packages
</a></h3>
572 Use : dpkg-buildpackage -rfakeroot
575 You should then have your LTTV .deb files created for your architecture.
577 <h3><a href=
"#TOCpkglttng" name=
"pkglttng">Create custom LTTng packages
</a></h3>
579 For building LTTng Debian packages :
580 get the build tree with patches applies as explained in section
2.
583 make menuconfig (or xconfig or config) (customize your configuration)
584 make-kpkg kernel_image
587 You will then see your freshly created .deb in /usr/src. Install it with
589 dpkg -i /usr/src/(image-name).deb
592 Then, follow the section
"Editing the system wide configuration" in section
2.