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 Eclipse LTTng trace analysis tool is released under the EPL and uses the
102 LTTV trace reading library (LGPLv2.1).
104 The UST (Userspace Tracing) and the Userspace RCU libraries are released under
105 the LGPLv2.1 license, which allows linking with non-GPL (BSD, proprietary...)
106 applications. The associated headers are released under MIT-style/BSD-style
109 Please refer to each particular file licensing for details.
111 <h3><a href=
"#TOCarch" name=
"arch">Supported architectures
</a></h3>
115 <li> PowerPC
32 and
64 bits
117 <li> Other ARM (with limited timestamping precision, e.g.
1HZ. Need
118 architecture-specific support for better precision)
120 <li> sh (partial architecture-specific instrumentation)
121 <li> sparc64 (partial architecture-specific instrumentation)
122 <li> s390 (partial architecture-specific instrumentation)
123 <li> Other architectures supported without architecture-specific instrumentation
124 and with low-resolution timestamps.
<br>
129 <li> Intel
32/
64 bits
130 <li> PowerPC
32 and
64 bits
131 <li> Possibly others. Takes care of endianness and type size difference between
132 the LTTng traces and the LTTV analysis tool.
137 <h2><a href=
"#TOCsection1" name=
"section1">Installation from sources
</a></h2>
140 <h3><a href=
"#TOCprerequisites" name=
"prerequisites">Prerequisites
</a></h3>
143 Tools needed to follow the package download steps :
151 You have to install the standard development libraries and programs necessary
152 to compile a kernel :
155 (from Documentation/Changes in the Linux kernel tree)
156 Gnu C
2.95.3 # gcc --version
157 Gnu make
3.79.1 # make --version
158 binutils
2.12 # ld -v
159 util-linux
2.10o # fdformat --version
160 module-init-tools
0.9.10 # depmod -V
164 You might also want to have libncurses5 to have the text mode kernel
165 configuration menu, but there are alternatives.
168 Prerequisites for LTTV
0.x.x installation are :
172 gtk
2.4 or better development libraries
173 (Debian : libgtk2.0, libgtk2.0-dev)
174 (Fedora : gtk2, gtk2-devel)
175 note : For Fedora users : this might require at least core
3 from Fedora,
176 or you might have to compile your own GTK2 library.
177 glib
2.4 or better development libraries
178 (Debian : libglib2.0-
0, libglib2.0-dev)
179 (Fedora : glib2, glib2-devel)
180 libpopt development libraries
181 (Debian : libpopt0, libpopt-dev)
183 libpango development libraries
184 (Debian : libpango1.0, libpango1.0-dev)
185 (Fedora : pango, pango-devel)
186 libc6 development librairies
187 (Debian : libc6, libc6-dev)
188 (Fedora : glibc, glibc)
195 See the list of compatibilities between LTTng, ltt-control and LTTV at :
197 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
198 versions compatibility
</a>.
201 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
207 (see http://ltt.polymtl.ca/lttng for package listing)
208 wget http://ltt.polymtl.ca/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
209 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
213 <h3><a href=
"#TOCgetlttngsrc" name=
"getlttngsrc">Getting LTTng kernel sources
</a></h3>
218 wget http://kernel.org/pub/linux/kernel/v2.6/linux-
2.6.X.tar.bz2
219 bzip2 -cd linux-
2.6.X.tar.bz2 | tar xvof -
221 - For LTTng
0.9.4- cat /usr/src/lttng/patch*-
2.6.X-lttng-
0.x.xx* | patch -p1
222 - For LTTng
0.9.5+ apply the patches in the order specified in the series file,
225 mv linux-
2.6.X linux-
2.6.X-lttng-
0.x.xx
229 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing a LTTng kernel
</a></h3>
233 cd /usr/src/linux-
2.6.X-lttng-
0.x.xx
234 make menuconfig (or make xconfig or make config)
235 Select the
< Help
> button if you are not familiar with kernel
237 Items preceded by [*] means they has to be built into the kernel.
238 Items preceded by [M] means they has to be built as modules.
239 Items preceded by [ ] means they should be removed.
240 go to the
"General setup" section
241 Select the following options :
242 [*] Prompt for development and/or incomplete code/drivers
244 [*] Activate userspace markers ABI (experimental, optional)
245 [*] Immediate value optimization (optional)
246 [*] Linux Trace Toolkit Next Generation (LTTng) ---
>
247 <M
> or
<*
> Compile lttng tracing probes
248 <M
> or
<*
> Linux Trace Toolkit High-speed Lockless Data Relay
249 <M
> or
<*
> Linux Trace Toolkit Lock-Protected Data Relay
250 <M
> or
<*
> Linux Trace Toolkit Serializer
251 <M
> or
<*
> Linux Trace Toolkit Marker Control
252 <M
> or
<*
> Linux Trace Toolkit Tracer
253 [*] Align Linux Trace Toolkit Traces
254 <M
> or
<*
> Support logging events from userspace
255 [*] Support trace extraction from crash dump
256 <M
> or
<*
> Linux Trace Toolkit Trace Controller
257 <M
> or
<*
> Linux Trace Toolkit State Dump
263 (if necessary, create a initrd with mkinitrd or your preferate alternative)
264 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
269 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
272 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
273 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
274 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
275 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
276 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
277 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
278 that comes first is the default kernel)
280 select the right entry at the yaboot prompt (see choices : tab, select : type
281 the kernel name followed by enter)
282 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
286 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
287 configuration
</a></h3>
290 You must activate debugfs and specify a mount point. This is typically done in
291 fstab such that it happens at boot time. If you have never used DebugFS before,
292 these operation would do this for you :
296 cp /etc/fstab /etc/fstab.lttng.bkp
297 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
301 then, rebooting or issuing the following command will activate debugfs :
307 You need to load the LTT modules to be able to control tracing from user
308 space. This is done by issuing the following commands. Note however
309 these commands load all LTT modules. Depending on what options you chose to
310 compile statically, you may not need to issue all these commands.
313 modprobe ltt-trace-control
314 modprobe ltt-marker-control
316 modprobe ltt-serialize
319 modprobe kernel-trace
325 modprobe syscall-trace
327 #if locking tracing is wanted, uncomment the following
328 #modprobe lockdep-trace
332 If you want to have complete information about the kernel state (including all
333 the process names), you need to load the ltt-statedump module. This is done by
334 issuing the command :
337 modprobe ltt-statedump
340 You can automate at boot time loading the ltt-control module by :
343 cp /etc/modules /etc/modules.bkp
344 echo ltt-trace-control
>> /etc/modules
345 echo ltt-marker-control
>> /etc/modules
346 echo ltt-tracer
>> /etc/modules
347 echo ltt-serialize
>> /etc/modules
348 echo ltt-relay
>> /etc/modules
349 echo ipc-trace
>> /etc/modules
350 echo kernel-trace
>> /etc/modules
351 echo mm-trace
>> /etc/modules
352 echo net-trace
>> /etc/modules
353 echo fs-trace
>> /etc/modules
354 echo jbd2-trace
>> /etc/modules
355 echo ext4-trace
>> /etc/modules
356 echo syscall-trace
>> /etc/modules
357 echo trap-trace
>> /etc/modules
358 #if locking tracing is wanted, uncomment the following
359 #echo lockdep-trace
>> /etc/modules
363 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
364 ltt-control package (on the traced machine)
</a></h3>
366 (note : the ltt-control package contains lttd and lttctl. Although it has the
367 same name as the ltt-control kernel module, they are *not* the same thing.)
372 wget http://ltt.polymtl.ca/lttng/ltt-control-
0.x-xxxx2006.tar.gz
373 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
374 cd ltt-control-
0.x-xxxx2006
375 (refer to README to see the development libraries that must be installed on you
380 # (run ldconfig to ensure new shared objects are taken into account)
384 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
387 Make sure you selected the kernel menuconfig option :
388 <M
> or
<*
> Support logging events from userspace
389 And that the ltt-userspace-event kernel module is loaded if selected as a
392 Simple userspace tracing is available through
393 echo
"some text to record" > /mnt/debugfs/ltt/write_event
395 It will appear in the trace under event :
400 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
401 (on the visualisation machine, same
402 or different from the visualisation machine)
</a></h3>
407 wget http://ltt.polymtl.ca/packages/lttv-
0.x.xx-xxxx2008.tar.gz
408 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
409 cd lttv-
0.x.xx-xxxx2008
410 (refer to README to see the development libraries that must be installed on your
415 # (run ldconfig to ensure new shared objects are taken into account)
422 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
424 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
429 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
430 tracing and analyse traces
</a></h3>
432 lttv-gui (or /usr/local/bin/lttv-gui)
433 - Spot the
"Tracing Control" icon : click on it
434 (it's a traffic light icon)
435 - enter the root password
439 * You should now see a trace
442 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
444 The tracing can be controlled from a terminal by using the lttctl command (as
449 lttctl -C -w /tmp/trace1 trace1
451 Stop tracing and destroy trace channels :
455 see lttctl --help for details.
458 (note : to see if the buffers has been filled, look at the dmesg output after
459 lttctl -D or after stopping tracing from the GUI, it will show an event lost
460 count. If it is the case, try using larger buffers. See lttctl --help to learn
461 how. lttv now also shows event lost messages in the console when loading a trace
462 with missing events or lost subbuffers.)
464 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
466 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
467 graphical plugins available.
469 For example, a simple trace dump in text format is available with :
471 lttv -m textDump -t /tmp/trace
474 See lttv -m textDump --help for detailed command line options of textDump.
476 It is, in the current state of the project, very useful to use
"grep" on the
477 text output to filter by specific event fields. You can later copy the timestamp
478 of the events to the clipboard and paste them in the GUI by clicking on the
479 bottom right label
"Current time". Support for this type of filtering should
480 be added to the filter module soon.
482 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
484 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
485 hybrid. It can be especially useful when studying big workloads on a long period
488 When using this mode, the most important, low rate control information will be
489 recorded during all the trace by lttd (i.e. process creation/exit). The high
490 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
491 flight recorder buffer (now named flight-channelname_X).
493 The following lttctl commands take an hybrid trace :
495 Create trace channel, start lttd on normal channels, start tracing:
497 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
500 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
502 lttctl -D -w /tmp/trace2 trace2
505 Each
"overwrite" channel is flight recorder channel.
508 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
509 <li>Flight recorder mode
</li>
511 The flight recorder mode writes data into overwritten buffers for all channels,
512 including control channels, except for the facilities tracefiles. It consists of
513 setting all channels to
"overwrite".
515 The following lttctl commands take a flight recorder trace :
517 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
519 lttctl -D -w /tmp/trace3 trace3
525 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
529 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
530 instrumentation
</a></h3>
534 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>
536 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
540 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
541 for LTTng probe examples.
543 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
545 Add new events to userspace programs with
546 <a href=
"http://ltt.polymtl.ca/packages/">userspace markers packages
</a>.
547 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
548 allows inserting markers in executables and libraries, currently only on x86_32
551 href=
"http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
554 Note that a new design document for a
3rd generation of tracepoint/marker-based
555 userspace tracing is available at
<a
556 href=
"http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
557 Design
</a>. This new infrastructure is not yet implemented.
560 The easy quick-and-dirty way to perform userspace tracing is currently to write
561 an string to /mnt/debugfs/ltt/write_event. See
<a
562 href=
"#userspacetracing">Userspace tracing
</a> in the
563 installation for sources section of this document.
567 <h2><a href=
"#TOCsection4" name=
"section4">Creating Debian or RPM packages
</a></h2>
570 <h3><a href=
"#TOCpkgdebian" name=
"pkgdebian">Create custom LTTV Debian packages
</a></h3>
573 Use : dpkg-buildpackage -rfakeroot
576 You should then have your LTTV .deb files created for your architecture.
578 <h3><a href=
"#TOCpkglttng" name=
"pkglttng">Create custom LTTng packages
</a></h3>
580 For building LTTng Debian packages :
581 get the build tree with patches applies as explained in section
2.
584 make menuconfig (or xconfig or config) (customize your configuration)
585 make-kpkg kernel_image
588 You will then see your freshly created .deb in /usr/src. Install it with
590 dpkg -i /usr/src/(image-name).deb
593 Then, follow the section
"Editing the system wide configuration" in section
2.