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 : September
3,
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 the LTTng kernel patchset, LTTng
80 modules, ltt-control, LTTV, please refer to :
82 href=
"http://lttng.org/cgi-bin/gitweb.cgi?p=lttv.git;a=blob_plain;f=doc/developer/lttng-lttv-compatibility.html;hb=HEAD">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
2.16 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://lttng.org/cgi-bin/gitweb.cgi?p=lttv.git;a=blob_plain;f=doc/developer/lttng-lttv-compatibility.html;hb=HEAD">LTTng+LTTV versions compatibility
</a>.
200 <h3><a href=
"#TOCgetlttng" name=
"getlttng">Getting the LTTng packages
</a></h3>
206 (see http://lttng.org/files/lttng for package listing)
207 wget http://lttng.org/files/lttng/patch-
2.6.X-lttng-
0.x.xx.tar.bz2
208 wget http://lttng.org/files/lttng/lttng-modules-
0.x.tar.bz2
209 bzip2 -cd patch-
2.6.X-lttng-
0.x.xx.tar.bz2 | tar xvof -
210 bzip2 -cd lttng-modules-
0.x.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 [*] Immediate value optimization (optional)
251 (if necessary, create a initrd with mkinitrd or your preferate alternative)
252 (mkinitrd -o /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx)
257 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
260 cp vmlinux.strip /boot/vmlinux-
2.6.X-lttng-
0.x.xx
261 cp System.map /boot/System.map-
2.6.X-lttng-
0.x.xx
262 cp .config /boot/config-
2.6.X-lttng-
0.x.xx
263 depmod -ae -F /boot/System.map-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
264 mkinitrd /boot/initrd.img-
2.6.X-lttng-
0.x.xx
2.6.X-lttng-
0.x.xx
265 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
266 that comes first is the default kernel)
268 select the right entry at the yaboot prompt (see choices : tab, select : type
269 the kernel name followed by enter)
270 Select the Linux
2.6.X-lttng-
0.x.xx kernel in your boot loader.
275 <h3><a href=
"#TOCinstalllttng" name=
"installlttng">Installing the LTTng modules
</a></h3>
279 cd /usr/src/lttng/lttng-modules-
0.x
280 KERNELDIR=/usr/src/linux-
2.6.X-lttng-
0.x.xx make
281 KERNELDIR=/usr/src/linux-
2.6.X-lttng-
0.x.xx make modules_install
283 Optionally, make can be prefixed with tracer options:
285 EXTRA_CFLAGS=
"-DLTT_DEBUG_EVENT_SIZE" make
286 EXTRA_CFLAGS=
"-DLTT_VMCORE" make
287 EXTRA_CFLAGS=
"-DLTT_DEBUG_EVENT_SIZE -DLTT_VMCORE" make
290 <h3><a href=
"#TOCeditconfig" name=
"editconfig">Editing the system wide
291 configuration
</a></h3>
294 You must activate debugfs and specify a mount point. This is typically done in
295 fstab such that it happens at boot time. If you have never used DebugFS before,
296 these operation would do this for you :
300 cp /etc/fstab /etc/fstab.lttng.bkp
301 echo
"debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
305 then, rebooting or issuing the following command will activate debugfs :
311 You need to load the LTT modules to be able to control tracing from user
312 space. This is done by issuing the following commands. Note however
313 these commands load all LTT modules. Depending on what options you chose to
314 compile statically, you may not need to issue all these commands.
317 modprobe ltt-trace-control
318 modprobe ltt-marker-control
322 modprobe kernel-trace
328 modprobe syscall-trace
331 #if locking tracing is wanted, uncomment the following
332 #modprobe lockdep-trace
336 If you want to have complete information about the kernel state (including all
337 the process names), you need to load the ltt-statedump module. This is done by
338 issuing the command :
341 modprobe ltt-statedump
344 You can automate at boot time loading the ltt-control module by :
347 cp /etc/modules /etc/modules.bkp
348 echo ltt-trace-control
>> /etc/modules
349 echo ltt-marker-control
>> /etc/modules
350 echo ltt-tracer
>> /etc/modules
351 echo ltt-relay
>> /etc/modules
352 echo ipc-trace
>> /etc/modules
353 echo kernel-trace
>> /etc/modules
354 echo mm-trace
>> /etc/modules
355 echo net-trace
>> /etc/modules
356 echo fs-trace
>> /etc/modules
357 echo jbd2-trace
>> /etc/modules
358 echo ext4-trace
>> /etc/modules
359 echo syscall-trace
>> /etc/modules
360 echo trap-trace
>> /etc/modules
361 #if locking tracing is wanted, uncomment the following
362 #echo lockdep-trace
>> /etc/modules
366 <h3><a href=
"#TOCgetlttctl" name=
"getlttctl">Getting and installing the
367 ltt-control package (on the traced machine)
</a></h3>
369 (note : the ltt-control package contains lttd and lttctl. Although it has the
370 same name as the ltt-control kernel module, they are *not* the same thing.)
375 wget http://lttng.org/files/lttng/ltt-control-
0.x-xxxx2006.tar.gz
376 gzip -cd ltt-control-
0.x-xxxx2008.tar.gz | tar xvof -
377 cd ltt-control-
0.x-xxxx2006
378 (refer to README to see the development libraries that must be installed on you
383 # (run ldconfig to ensure new shared objects are taken into account)
387 <h3><a href=
"#TOCuserspacetracing" name=
"userspacetracing">Userspace tracing
</a></h3>
390 Make sure you selected the kernel menuconfig option :
391 <M
> or
<*
> Support logging events from userspace
392 And that the ltt-userspace-event kernel module is loaded if selected as a
395 Simple userspace tracing is available through
396 echo
"some text to record" > /mnt/debugfs/ltt/write_event
398 It will appear in the trace under event :
403 <h3><a href=
"#TOCgetlttv" name=
"getlttv">Getting and installing the LTTV package
404 (on the visualisation machine, same
405 or different from the visualisation machine)
</a></h3>
410 wget http://lttng.org/files/packages/lttv-
0.x.xx-xxxx2008.tar.gz
411 gzip -cd lttv-
0.x.xx-xxxx2008.tar.gz | tar xvof -
412 cd lttv-
0.x.xx-xxxx2008
413 (refer to README to see the development libraries that must be installed on your
418 # (run ldconfig to ensure new shared objects are taken into account)
425 <h2><a href=
"#TOCsection2" name=
"section2">Using LTTng and LTTV
</a></h2>
427 <li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing
</b></li>
432 <h3><a href=
"#TOCuselttvgui" name=
"uselttvgui">Use graphical LTTV to control
433 tracing and analyse traces
</a></h3>
435 lttv-gui (or /usr/local/bin/lttv-gui)
436 - Spot the
"Tracing Control" icon : click on it
437 (it's a traffic light icon)
438 - enter the root password
442 * You should now see a trace
445 <h3><a href=
"#TOCuselttngtext" name=
"uselttngtext">Use text mode LTTng to control tracing
</a></h3>
447 The tracing can be controlled from a terminal by using the lttctl command (as
452 lttctl -C -w /tmp/trace1 trace1
454 Stop tracing and destroy trace channels :
458 see lttctl --help for details.
461 (note : to see if the buffers has been filled, look at the dmesg output after
462 lttctl -D or after stopping tracing from the GUI, it will show an event lost
463 count. If it is the case, try using larger buffers. See lttctl --help to learn
464 how. lttv now also shows event lost messages in the console when loading a trace
465 with missing events or lost subbuffers.)
467 <h3><a href=
"#TOCuselttvtext" name=
"uselttvtext">Use text mode LTTV
</a></h3>
469 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
470 graphical plugins available.
472 For example, a simple trace dump in text format is available with :
474 lttv -m textDump -t /tmp/trace
477 See lttv -m textDump --help for detailed command line options of textDump.
479 It is, in the current state of the project, very useful to use
"grep" on the
480 text output to filter by specific event fields. You can later copy the timestamp
481 of the events to the clipboard and paste them in the GUI by clicking on the
482 bottom right label
"Current time". Support for this type of filtering should
483 be added to the filter module soon.
485 <h3><a href=
"#TOChybrid" name=
"hybrid">Tracing in
"Hybrid" mode
</a></h3>
487 Starting from LTTng
0.5.105 and ltt-control
0.20, a new mode can be used :
488 hybrid. It can be especially useful when studying big workloads on a long period
491 When using this mode, the most important, low rate control information will be
492 recorded during all the trace by lttd (i.e. process creation/exit). The high
493 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
494 flight recorder buffer (now named flight-channelname_X).
496 The following lttctl commands take an hybrid trace :
498 Create trace channel, start lttd on normal channels, start tracing:
500 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=
1 trace2
503 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
505 lttctl -D -w /tmp/trace2 trace2
508 Each
"overwrite" channel is flight recorder channel.
511 <h3><a href=
"#TOCflight" name=
"flight">Tracing in flight recorder mode
</a></h3>
512 <li>Flight recorder mode
</li>
514 The flight recorder mode writes data into overwritten buffers for all channels,
515 including control channels, except for the facilities tracefiles. It consists of
516 setting all channels to
"overwrite".
518 The following lttctl commands take a flight recorder trace :
520 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=
1 trace3
522 lttctl -D -w /tmp/trace3 trace3
528 <h2><a href=
"#TOCsection3" name=
"section3">Adding new instrumentations with the
532 <h3><a href=
"#TOCkerneltp" name=
"kerneltp">Adding kernel
533 instrumentation
</a></h3>
537 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>
539 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
543 href=
"http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/
</a>
544 for LTTng probe examples.
546 <h3><a href=
"#TOCusertp" name=
"usertp">Adding userspace instrumentation
</a></h3>
548 Add new events to userspace programs with
549 <a href=
"http://lttng.org/files/packages/">userspace markers packages
</a>.
550 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
551 allows inserting markers in executables and libraries, currently only on x86_32
554 href=
"http://lttng.org/files/packages/markers-userspace-0.5.tar.bz2">markers-userspace-
0.5.tar.bz2
</a> or more recent.
557 Note that tracepoint/marker-based userspace tracing is available at
<a
558 href=
"http://lttng.org/ust/">LTTng User-space Tracer (UST)
</a>.
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.