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>
19 <li><a href=
"#section1" name=
"TOCsection1">Installing LTTng and LTTV from
22 <li><a href=
"#prerequisites" name=
"TOCprerequisites">Prerequisistes
</li>
23 <li><a href=
"#getlttng" name=
"TOCgetlttng">Getting the LTTng packages
</li>
24 <li><a href=
"#getlttngsrc" name=
"TOCgetlttngsrc">Getting the LTTng kernel sources
</li>
25 <li><a href=
"#installlttng" name=
"TOCinstalllttng">Installing a LTTng kernel
</li>
26 <li><a href=
"#editconfig" name=
"TOCeditconfig">Editing the system wide
28 <li><a href=
"#getlttctl" name=
"TOCgetlttctl">Getting and installing the
29 ltt-control package
</li>
30 <li><a href=
"#userspacetracing" name=
"TOCuserspacetracing">Userspace Tracing
</li>
31 <li><a href=
"#getlttv" name=
"TOCgetlttv">Getting and installing the LTTV package
</ul>
33 <li><a href=
"#section2" name=
"TOCsection2">Using LTTng and LTTV
</a></li>
35 <li><a href=
"#uselttvgui" name=
"TOCuselttvgui">Use graphical LTTV to control
36 tracing and analyse traces
</a></li>
37 <li><a href=
"#uselttngtext" name=
"TOCuselttngtext">Use text mode LTTng to
38 control tracing
</a></li>
39 <li><a href=
"#uselttvtext" name=
"TOCuselttvtext">Use text mode LTTV
</a></li>
40 <li><a href=
"#hybrid" name=
"TOChybrid">Tracing in
"Hybrid" mode
</a></li>
41 <li><a href=
"#flight" name=
"TOCflight">Tracing in flight recorder mode
</a></li>
44 <li><a href=
"#section3" name=
"TOCsection3">Adding kernel and user-space
47 <li><a href=
"#kerneltp" name=
"TOCkerneltp">Adding kernel instrumentation
</a></li>
48 <li><a href=
"#usertp" name=
"TOCusertp">Adding userspace instrumentation
</a></li>
51 <li><a href=
"#section4" name=
"TOCsection4">Creating Debian and RPM packages
54 <li><a href=
"#pkgdebian" name=
"TOCpkgdebian">Create custom LTTV Debian
55 <li><a href=
"#pkglttng" name=
"TOCpkglttng">Create custom LTTng packages
</a></li>
62 <h2><a href=
"#TOCintro" name=
"intro">Introduction
</a></h2>
64 This document is made of four parts : the first one explains how
65 to install LTTng and LTTV from sources, the second one describes the steps
66 to follow to trace a system and view it. The third part explains
67 briefly how to add a new trace point to the kernel and to user space
68 applications. The fourth and last part explains how to create Debian or RPM
69 packages from the LTTng and LTTV sources.
71 These operations are made for installing the LTTng
0.86 tracer on a linux
2.6.X
72 kernel. You will also find instructions for installation of LTTV
0.12.x : the
73 Linux Trace Toolkit Viewer.
74 To see the list of compatibilities between LTTng, ltt-control, LTTV, please
77 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility
</a>
78 The lttng patch is necessary to have the tracing hooks in the kernel.
82 Supported architectures :
86 <li> PowerPC
32 and
64 bits
87 <li> ARM (with limited timestamping precision, e.g.
1HZ. Need
88 architecture-specific support for better precision)
94 <li> PowerPC
32 and
64 bits
95 <li> Possibly others. Takes care of endianness and type size difference between
96 the LTTng traces and the LTTV analysis tool.
101 <h2><a href=
"#TOCsection1" name=
"section1">Installation from sources
</a></h2>
104 <h3><a href=
"#TOCprerequisites" name=
"prerequisites">Prerequisites
</a></h3>
107 Tools needed to follow the package download steps :
115 You have to install the standard development libraries and programs necessary
116 to compile a kernel :
119 (from Documentation/Changes in the Linux kernel tree)
120 Gnu C
2.95.3 # gcc --version
121 Gnu make
3.79.1 # make --version
122 binutils
2.12 # ld -v
123 util-linux
2.10o # fdformat --version
124 module-init-tools
0.9.10 # depmod -V
128 You might also want to have libncurses5 to have the text mode kernel
129 configuration menu, but there are alternatives.
132 Prerequisites for LTTV
0.x.x installation are :
136 gtk
2.4 or better development libraries
137 (Debian : libgtk2.0, libgtk2.0-dev)
138 (Fedora : gtk2, gtk2-devel)
139 note : For Fedora users : this might require at least core
3 from Fedora,
140 or you might have to compile your own GTK2 library.
141 glib
2.4 or better development libraries
142 (Debian : libglib2.0-
0, libglib2.0-dev)
143 (Fedora : glib2, glib2-devel)
144 libpopt development libraries
145 (Debian : libpopt0, libpopt-dev)
147 libpango development libraries
148 (Debian : libpango1.0, libpango1.0-dev)
149 (Fedora : pango, pango-devel)
150 libc6 development librairies
151 (Debian : libc6, libc6-dev)
152 (Fedora : glibc, glibc)
159 See the list of compatibilities between LTTng, ltt-control and LTTV at :
161 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
162 versions compatibility
</a>.
165 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
171 (see http://ltt.polymtl.ca/lttng for package listing)
172 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
173 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
177 <h3><a href=
"#TOCgetlttngsrc" name=
"getlttngsrc">Getting LTTng kernel sources
</a></h3>
182 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
183 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
185 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
186 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
189 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
193 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing a LTTng kernel
</a></h3>
197 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
198 make menuconfig (or make xconfig or make config)
199 Select the < Help
> button if you are not familiar with kernel
201 Items preceded by [*] means they has to be built into the kernel.
202 Items preceded by [M] means they has to be built as modules.
203 Items preceded by [ ] means they should be removed.
204 go to the
"General setup" section
205 Select the following options :
206 [*] Prompt for development and/or incomplete code/drivers
208 [*] Activate userspace markers ABI (experimental, optional)
209 [*] Immediate value optimization (optional)
210 [*] Linux Trace Toolkit Next Generation (LTTng) --->
211 <M> or <*
> Compile lttng tracing probes
212 <M> or <*
> Linux Trace Toolkit High-speed Lockless Data Relay
213 <M> or <*
> Linux Trace Toolkit Lock-Protected Data Relay
214 <M> or <*
> Linux Trace Toolkit Serializer
215 <M> or <*
> Linux Trace Toolkit Marker Control
216 <M> or <*
> Linux Trace Toolkit Tracer
217 [*] Align Linux Trace Toolkit Traces
218 <M> or <*
> Support logging events from userspace
219 [*] Support trace extraction from crash dump
220 <M> or <*
> Linux Trace Toolkit Trace Controller
221 <M> or <*
> Linux Trace Toolkit State Dump
227 (if necessary, create a initrd with mkinitrd or your preferate alternative)
228 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
233 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
236 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
237 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
238 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
239 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
240 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
241 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
242 that comes first is the default kernel)
244 select the right entry at the yaboot prompt (see choices : tab, select : type
245 the kernel name followed by enter)
246 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
250 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
251 configuration
</a></h3>
254 You must activate debugfs and specify a mount point. This is typically done in
255 fstab such that it happens at boot time. If you have never used DebugFS before,
256 these operation would do this for you :
260 cp /etc/fstab /etc/fstab.lttng.bkp
261 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
265 then, rebooting or issuing the following command will activate debugfs :
271 You need to load the LTT modules to be able to control tracing from user
272 space. This is done by issuing the following commands. Note however
273 these commands load all LTT modules. Depending on what options you chose to
274 compile statically, you may not need to issue all these commands.
277 modprobe ltt-trace-control
278 modprobe ltt-marker-control
280 modprobe ltt-serialize
283 modprobe kernel-trace
289 modprobe syscall-trace
291 #if locking tracing is wanted, uncomment the following
292 #modprobe lockdep-trace
296 If you want to have complete information about the kernel state (including all
297 the process names), you need to load the ltt-statedump module. This is done by
298 issuing the command :
301 modprobe ltt-statedump
304 You can automate at boot time loading the ltt-control module by :
307 cp /etc/modules /etc/modules.bkp
308 echo ltt-trace-control
>> /etc/modules
309 echo ltt-marker-control
>> /etc/modules
310 echo ltt-tracer
>> /etc/modules
311 echo ltt-serialize
>> /etc/modules
312 echo ltt-relay
>> /etc/modules
313 echo ipc-trace
>> /etc/modules
314 echo kernel-trace
>> /etc/modules
315 echo mm-trace
>> /etc/modules
316 echo net-trace
>> /etc/modules
317 echo fs-trace
>> /etc/modules
318 echo jbd2-trace
>> /etc/modules
319 echo ext4-trace
>> /etc/modules
320 echo syscall-trace
>> /etc/modules
321 echo trap-trace
>> /etc/modules
322 #if locking tracing is wanted, uncomment the following
323 #echo lockdep-trace
>> /etc/modules
327 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
328 ltt-control package (on the traced machine)
</a></h3>
330 (note : the ltt-control package contains lttd and lttctl. Although it has the
331 same name as the ltt-control kernel module, they are *not* the same thing.)
336 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
337 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
338 cd ltt-control-
0.x-xxxx2006
339 (refer to README to see the development libraries that must be installed on you
346 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
349 Make sure you selected the kernel menuconfig option :
350 <M> or <*
> Support logging events from userspace
351 And that the ltt-userspace-event kernel module is loaded if selected as a
354 Simple userspace tracing is available through
355 echo
"some text to record" > /mnt/debugfs/ltt/write_event
357 It will appear in the trace under event :
362 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
363 (on the visualisation machine, same
364 or different from the visualisation machine)
</a></h3>
369 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
370 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
371 cd lttv-
0.x.xx-xxxx2008
372 (refer to README to see the development libraries that must be installed on your
382 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
384 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
389 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
390 tracing and analyse traces
</a></h3>
392 lttv-gui (or /usr/local/bin/lttv-gui)
393 - Spot the
"Tracing Control" icon : click on it
394 (it's a traffic light icon)
395 - enter the root password
399 * You should now see a trace
402 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
404 The tracing can be controlled from a terminal by using the lttctl command (as
409 lttctl -C -w /tmp/trace1 trace1
411 Stop tracing and destroy trace channels :
415 see lttctl --help for details.
418 (note : to see if the buffers has been filled, look at the dmesg output after
419 lttctl -R or after stopping tracing from the GUI, it will show an event lost
420 count. If it is the case, try using larger buffers. See lttctl --help to learn
421 how. lttv now also shows event lost messages in the console when loading a trace
422 with missing events or lost subbuffers.)
424 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
426 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
427 graphical plugins available.
429 For example, a simple trace dump in text format is available with :
431 lttv -m textDump -t /tmp/trace
434 See lttv -m textDump --help for detailed command line options of textDump.
436 It is, in the current state of the project, very useful to use
"grep" on the
437 text output to filter by specific event fields. You can later copy the timestamp
438 of the events to the clipboard and paste them in the GUI by clicking on the
439 bottom right label
"Current time". Support for this type of filtering should
440 be added to the filter module soon.
442 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
444 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
445 hybrid. It can be especially useful when studying big workloads on a long period
448 When using this mode, the most important, low rate control information will be
449 recorded during all the trace by lttd (i.e. process creation/exit). The high
450 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
451 flight recorder buffer (now named flight-channelname_X).
453 The following lttctl commands take an hybrid trace :
455 Create trace channel, start lttd on normal channels, start tracing:
457 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
460 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
462 lttctl -D -w /tmp/trace2 trace2
465 Each
"overwrite" channel is flight recorder channel.
468 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
469 <li>Flight recorder mode
</li>
471 The flight recorder mode writes data into overwritten buffers for all channels,
472 including control channels, except for the facilities tracefiles. It consists of
473 setting all channels to
"overwrite".
475 The following lttctl commands take a flight recorder trace :
477 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
479 lttctl -D -w /tmp/trace3 trace3
485 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
489 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
490 instrumentation
</a></h3>
494 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>
496 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
500 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
501 for LTTng probe examples.
503 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
505 Add new events to userspace programs with
506 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a>.
507 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
508 allows inserting markers in executables and libraries, currently only on x86_32
511 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
514 Note that a new design document for a
3rd generation of tracepoint/marker-based
515 userspace tracing is available at
<a
516 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
517 Design
</a>. This new infrastructure is not yet implemented.
520 The easy quick-and-dirty way to perform userspace tracing is currently to write
521 an string to /mnt/debugfs/ltt/write_event. See
<a
522 href=
"#userspacetracing">Userspace tracing
</a> in the
523 installation for sources section of this document.
527 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
530 <h3><a href=
"#TOCpkgdebian" name=
"pkgdebian">Create custom LTTV Debian packages
</a></h3>
533 Use : dpkg-buildpackage -rfakeroot
536 You should then have your LTTV .deb files created for your architecture.
538 <h3><a href=
"#TOCpkglttng" name=
"pkglttng">Create custom LTTng packages
</a></h3>
540 For building LTTng Debian packages :
541 get the build tree with patches applies as explained in section
2.
544 make menuconfig (or xconfig or config) (customize your configuration)
545 make-kpkg kernel_image
548 You will then see your freshly created .deb in /usr/src. Install it with
550 dpkg -i /usr/src/(image-name).deb
553 Then, follow the section
"Editing the system wide configuration" in section
2.