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  <title>Linux Trace Toolkit Next Generation Manual</title>
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<h1>Linux Trace Toolkit Next Generation Manual</h1>

Author : Mathieu Desnoyers, September 2005<br>
Last update : January 21st, 2009<br>
(originally known as the LTTng QUICKSTART guide)

<h2>Table of Contents</h2>

<ul>
<li><a href="#intro" name="TOCintro">Introduction</a></li>
<ul>
<li><a href="#arch" name="TOCarch">Supported architectures</a></li>
</ul>

<li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
sources</a></li>
<ul>
<li><a href="#prerequisites" name="TOCprerequisites">Prerequisistes</li>
<li><a href="#getlttng" name="TOCgetlttng">Getting the LTTng packages</li>
<li><a href="#getlttngsrc" name="TOCgetlttngsrc">Getting the LTTng kernel sources</li>
<li><a href="#installlttng" name="TOCinstalllttng">Installing a LTTng kernel</li>
<li><a href="#editconfig" name="TOCeditconfig">Editing the system wide
configuration</a>
<li><a href="#getlttctl" name="TOCgetlttctl">Getting and installing the
ltt-control package</li>
<li><a href="#userspacetracing" name="TOCuserspacetracing">Userspace Tracing</li>
<li><a href="#getlttv" name="TOCgetlttv">Getting and installing the LTTV package</ul>

<li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
<ul>
<li><a href="#uselttvgui" name="TOCuselttvgui">Use graphical LTTV to control
tracing and analyse traces</a></li>
<li><a href="#uselttngtext" name="TOCuselttngtext">Use text mode LTTng to
control tracing</a></li>
<li><a href="#uselttvtext" name="TOCuselttvtext">Use text mode LTTV</a></li>
<li><a href="#hybrid" name="TOChybrid">Tracing in "Hybrid" mode</a></li>
<li><a href="#flight" name="TOCflight">Tracing in flight recorder mode</a></li>
</ul>

<li><a href="#section3" name="TOCsection3">Adding kernel and user-space
instrumentation</a>
<ul>
<li><a href="#kerneltp" name="TOCkerneltp">Adding kernel instrumentation</a></li>
<li><a href="#usertp" name="TOCusertp">Adding userspace instrumentation</a></li>
</ul>

<li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
from LTTV</a></li>
<ul>
<li><a href="#pkgdebian" name="TOCpkgdebian">Create custom LTTV Debian
<li><a href="#pkglttng" name="TOCpkglttng">Create custom LTTng packages</a></li>
</ul>

</ul>

<hr />

<h2><a href="#TOCintro" name="intro">Introduction</a></h2>
<p>
This document is made of five parts : the first one explains how
to install LTTng and LTTV from sources, the second one describes the steps
to follow to trace a system and view it. The third part explains
briefly how to add a new trace point to the kernel and to user space
applications. The fourth and last part explains how to create Debian or RPM
packages from the LTTng and LTTV sources.
<p>
These operations are made for installing the LTTng 0.86 tracer on a linux 2.6.X
kernel. You will also find instructions for installation of LTTV 0.12.x : the
Linux Trace Toolkit Viewer. 
To see the list of compatibilities between LTTng, ltt-control, LTTV, please
refer to :
<a
href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>

The ongoing work had the Linux Kernel Markers integrated in the mainline Linux
kernel since Linux 2.6.24 and the Tracepoints since 2.6.28. In its current
state, the lttng patchset is necessary to have the trace clocksource, the
instrumentation and the LTTng high-speed data extraction mechanism added to the
kernel.

<br>
<br>
<h3><a href="#TOCarch" name="arch">Supported architectures</a></h3>
<br>
LTTng :<br>
<br>
<li> x86 32/64 bits
<li> PowerPC 32 and 64 bits
<li> ARM (with limited timestamping precision, e.g. 1HZ. Need
architecture-specific support for better precision)
<li> MIPS
<li> sh (partial architecture-specific instrumentation)
<li> sparc64 (partial architecture-specific instrumentation)
<li> s390 (partial architecture-specific instrumentation)
<li> Other architectures supported without architecture-specific instrumentation
and with low-resolution timestamps.<br>
<br>
<br>
LTTV :<br>
<br>
<li> Intel 32/64 bits
<li> PowerPC 32 and 64 bits
<li> Possibly others. Takes care of endianness and type size difference between
the LTTng traces and the LTTV analysis tool.

<hr />


<h2><a href="#TOCsection1" name="section1">Installation from sources</a></h2>
<p>

<h3><a href="#TOCprerequisites" name="prerequisites">Prerequisites</a></h3>
<ul>
<p>
Tools needed to follow the package download steps :

<li>wget
<li>bzip2
<li>gzip
<li>tar

<p>
You have to install the standard development libraries and programs necessary
to compile a kernel :

<PRE>
(from Documentation/Changes in the Linux kernel tree)
Gnu C                2.95.3                # gcc --version
Gnu make             3.79.1                # make --version
binutils             2.12                  # ld -v
util-linux           2.10o                 # fdformat --version
module-init-tools    0.9.10                # depmod -V
</PRE>

<p>
You might also want to have libncurses5 to have the text mode kernel
configuration menu, but there are alternatives.

<p>
Prerequisites for LTTV 0.x.x installation are :

<PRE>
gcc 3.2 or better
gtk 2.4 or better development libraries
  (Debian : libgtk2.0, libgtk2.0-dev)
  (Fedora : gtk2, gtk2-devel)
  note : For Fedora users : this might require at least core 3 from Fedora,
  or you might have to compile your own GTK2 library.
glib 2.4 or better development libraries
  (Debian : libglib2.0-0, libglib2.0-dev)
  (Fedora : glib2, glib2-devel)
libpopt development libraries
  (Debian : libpopt0, libpopt-dev)
  (Fedora : popt)
libpango development libraries
  (Debian : libpango1.0, libpango1.0-dev)
  (Fedora : pango, pango-devel)
libc6 development librairies 
  (Debian : libc6, libc6-dev)
  (Fedora : glibc, glibc)
</PRE>
</ul>

<li>Reminder</li>

<p>
See the list of compatibilities between LTTng, ltt-control and LTTV at :
<a
href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
versions compatibility</a>.


<h3><a href="#TOCgetlttng" name="getlttng">Getting the LTTng packages</a></h3>

<PRE>
su -
mkdir /usr/src/lttng
cd /usr/src/lttng
(see http://ltt.polymtl.ca/lttng for package listing)
wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 | tar xvof -
</PRE>


<h3><a href="#TOCgetlttngsrc" name="getlttngsrc">Getting LTTng kernel sources</a></h3>

<PRE>
su -
cd /usr/src
wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
bzip2 -cd linux-2.6.X.tar.bz2 | tar xvof -
cd linux-2.6.X
- For LTTng 0.9.4- cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1
- For LTTng 0.9.5+ apply the patches in the order specified in the series file,
  or use quilt
cd ..
mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
</PRE>


<h3><a href="#TOCinstalllttng" name="installlttng">Installing a LTTng kernel</a></h3>

<PRE>
su -
cd /usr/src/linux-2.6.X-lttng-0.x.xx
make menuconfig (or make xconfig or make config)
    Select the < Help > button if you are not familiar with kernel
    configuration.
    Items preceded by [*] means they has to be built into the kernel.
    Items preceded by [M] means they has to be built as modules.
    Items preceded by [ ] means they should be removed.
  go to the "General setup" section
    Select the following options :
    [*] Prompt for development and/or incomplete code/drivers
    [*] Activate markers
    [*] Activate userspace markers ABI (experimental, optional)
    [*] Immediate value optimization (optional)
    [*] Linux Trace Toolkit Next Generation (LTTng) --->
    <M> or <*> Compile lttng tracing probes
    <M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
    <M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
    <M> or <*> Linux Trace Toolkit Serializer
    <M> or <*>   Linux Trace Toolkit Marker Control
    <M> or <*>     Linux Trace Toolkit Tracer
    [*] Align Linux Trace Toolkit Traces
    <M> or <*> Support logging events from userspace
    [*] Support trace extraction from crash dump
    <M> or <*> Linux Trace Toolkit Trace Controller
    <M> or <*> Linux Trace Toolkit State Dump
  Select <Exit>
  Select <Exit>
  Select <Yes>
make
make modules_install
(if necessary, create a initrd with mkinitrd or your preferate alternative)
(mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)

-- on X86, X86_64
make install
reboot
Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.

-- on PowerPC
cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
cp .config /boot/config-2.6.X-lttng-0.x.xx
depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
(edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
that comes first is the default kernel)
ybin
select the right entry at the yaboot prompt (see choices : tab, select : type
the kernel name followed by enter)
Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
--
</PRE>

<h3><a href="#TOCeditconfig" name="editconfig">Editing the system wide
configuration</a></h3>

<p>
You must activate debugfs and specify a mount point. This is typically done in
fstab such that it happens at boot time.  If you have never used DebugFS before,
these operation would do this for you :

<PRE>
mkdir /mnt/debugfs
cp /etc/fstab /etc/fstab.lttng.bkp
echo "debugfs         /mnt/debugfs    debugfs rw              0       0"  >> /etc/fstab
</PRE>

<p>
then, rebooting or issuing the following command will activate debugfs :
<PRE>
mount /mnt/debugfs
</PRE>

<p>
You need to load the LTT modules to be able to control tracing from user
space. This is done by issuing the following commands. Note however
these commands load all LTT modules. Depending on what options you chose to
compile statically, you may not need to issue all these commands. 

<PRE>
modprobe ltt-trace-control
modprobe ltt-marker-control
modprobe ltt-tracer
modprobe ltt-serialize
modprobe ltt-relay
modprobe ipc-trace
modprobe kernel-trace
modprobe mm-trace
modprobe net-trace
modprobe fs-trace
modprobe jbd2-trace
modprobe ext4-trace
modprobe syscall-trace
modprobe trap-trace
#if locking tracing is wanted, uncomment the following
#modprobe lockdep-trace
</PRE>

<p>
If you want to have complete information about the kernel state (including all
the process names), you need to load the ltt-statedump module. This is done by
issuing the command :

<PRE>
modprobe ltt-statedump
</PRE>
<p>
You can automate at boot time loading the ltt-control module by :

<PRE>
cp /etc/modules /etc/modules.bkp
echo ltt-trace-control >> /etc/modules
echo ltt-marker-control >> /etc/modules
echo ltt-tracer >> /etc/modules
echo ltt-serialize >> /etc/modules
echo ltt-relay >> /etc/modules
echo ipc-trace >> /etc/modules
echo kernel-trace >> /etc/modules
echo mm-trace >> /etc/modules
echo net-trace >> /etc/modules
echo fs-trace >> /etc/modules
echo jbd2-trace >> /etc/modules
echo ext4-trace >> /etc/modules
echo syscall-trace >> /etc/modules
echo trap-trace >> /etc/modules
#if locking tracing is wanted, uncomment the following
#echo lockdep-trace >> /etc/modules
</PRE>


<h3><a href="#TOCgetlttctl" name="getlttctl">Getting and installing the
ltt-control package (on the traced machine)</a></h3>
<p>
(note : the ltt-control package contains lttd and lttctl. Although it has the
same name as the ltt-control kernel module, they are *not* the same thing.)

<PRE>
su -
cd /usr/src
wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
gzip -cd ltt-control-0.x-xxxx2008.tar.gz | tar xvof -
cd ltt-control-0.x-xxxx2006
(refer to README to see the development libraries that must be installed on you
system)
./configure
make
make install
</PRE>

<h3><a href="#TOCuserspacetracing" name="userspacetracing">Userspace tracing</a></h3>

<PRE>
Make sure you selected the kernel menuconfig option :
    <M> or <*> Support logging events from userspace
And that the ltt-userspace-event kernel module is loaded if selected as a
module.

Simple userspace tracing is available through
echo "some text to record" > /mnt/debugfs/ltt/write_event

It will appear in the trace under event :
channel : userspace
event name : event
</PRE>

<h3><a href="#TOCgetlttv" name="getlttv">Getting and installing the LTTV package
(on the visualisation machine, same
or different from the visualisation machine)</a></h3>

<PRE>
su -
cd /usr/src
wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
gzip -cd lttv-0.x.xx-xxxx2008.tar.gz | tar xvof -
cd lttv-0.x.xx-xxxx2008
(refer to README to see the development libraries that must be installed on your
system)
./configure
make
make install
</PRE>

<hr />


<h2><a href="#TOCsection2" name="section2">Using LTTng and LTTV</a></h2>

<li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing</b></li>
<PRE>
ltt-armall
</PRE>

<h3><a href="#TOCuselttvgui" name="uselttvgui">Use graphical LTTV to control
tracing and analyse traces</a></h3>
<PRE>
lttv-gui (or /usr/local/bin/lttv-gui)
  - Spot the "Tracing Control" icon : click on it
      (it's a traffic light icon)
    - enter the root password
    - click "start"
    - click "stop"
    - Yes
      * You should now see a trace
</PRE>

<h3><a href="#TOCuselttngtext" name="uselttngtext">Use text mode LTTng to control tracing</a></h3>
<PRE>
The tracing can be controlled from a terminal by using the lttctl command (as
root).

Start tracing :

lttctl -C -w /tmp/trace1 trace1

Stop tracing and destroy trace channels :

lttctl -D trace1

see lttctl --help for details.
</PRE>
<p>
(note : to see if the buffers has been filled, look at the dmesg output after
lttctl -D or after stopping tracing from the GUI, it will show an event lost
count. If it is the case, try using larger buffers. See lttctl --help to learn 
how. lttv now also shows event lost messages in the console when loading a trace
with missing events or lost subbuffers.)

<h3><a href="#TOCuselttvtext" name="uselttvtext">Use text mode LTTV</a></h3>
<p>
Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
graphical plugins available.
<p>
For example, a simple trace dump in text format is available with :
<PRE>
lttv -m textDump -t /tmp/trace
</PRE>
<p>
See lttv -m textDump --help for detailed command line options of textDump.
<p>
It is, in the current state of the project, very useful to use "grep" on the
text output to filter by specific event fields. You can later copy the timestamp
of the events to the clipboard and paste them in the GUI by clicking on the
bottom right label "Current time". Support for this type of filtering should
be added to the filter module soon.

<h3><a href="#TOChybrid" name="hybrid">Tracing in "Hybrid" mode</a></h3>
<p>
Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
hybrid. It can be especially useful when studying big workloads on a long period
of time.
<p>
When using this mode, the most important, low rate control information will be
recorded during all the trace by lttd (i.e. process creation/exit). The high
rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
flight recorder buffer (now named flight-channelname_X).
<p>
The following lttctl commands take an hybrid trace :
<p>
Create trace channel, start lttd on normal channels, start tracing:
<PRE>
lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
</PRE>
<p>
Stop tracing, start lttd on flight recorder channels, destroy trace channels :
<PRE>
lttctl -D -w /tmp/trace2 trace2
</PRE>
<p>
Each "overwrite" channel is flight recorder channel.


<h3><a href="#TOCflight" name="flight">Tracing in flight recorder mode</a></h3>
<li>Flight recorder mode</li>
<p>
The flight recorder mode writes data into overwritten buffers for all channels,
including control channels, except for the facilities tracefiles. It consists of
setting all channels to "overwrite".
<p>
The following lttctl commands take a flight recorder trace :
<PRE>
lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
...
lttctl -D -w /tmp/trace3 trace3
</PRE>

<hr />


<h2><a href="#TOCsection3" name="section3">Adding new instrumentations with the
markers</a></h2>
<p>

<h3><a href="#TOCkerneltp" name="kerneltp">Adding kernel
instrumentation</a></h3>

<p>
See <a
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>
and <a
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
tree.
<p>
Also see <a
href="http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/</a>
for LTTng probe examples.

<h3><a href="#TOCusertp" name="usertp">Adding userspace instrumentation</a></h3>

Add new events to userspace programs with
<a href="http://ltt.polymtl.ca/packages/">userspace markers packages</a>.
Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
allows inserting markers in executables and libraries, currently only on x86_32
and x86_64.
See <a
href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.

<p>
Note that a new design document for a 3rd generation of tracepoint/marker-based
userspace tracing is available at <a
href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
Design</a>. This new infrastructure is not yet implemented.

<p>
The easy quick-and-dirty way to perform userspace tracing is currently to write
an string to /mnt/debugfs/ltt/write_event. See <a
href="#userspacetracing">Userspace tracing</a> in the
installation for sources section of this document.

<hr />

<h2><a href="#TOCsection4" name="section4">Creating Debian or RPM packages</a></h2>
<p>

<h3><a href="#TOCpkgdebian" name="pkgdebian">Create custom LTTV Debian packages</a></h3>

<PRE>
Use : dpkg-buildpackage -rfakeroot
</PRE>
<p>
You should then have your LTTV .deb files created for your architecture.

<h3><a href="#TOCpkglttng" name="pkglttng">Create custom LTTng packages</a></h3>
<p>
For building LTTng Debian packages :
get the build tree with patches applies as explained in section 2.

<PRE>
make menuconfig (or xconfig or config) (customize your configuration)
make-kpkg kernel_image
</PRE>
<p>
You will then see your freshly created .deb in /usr/src. Install it with
<PRE>
dpkg -i /usr/src/(image-name).deb
</PRE>
<p>
Then, follow the section "Editing the system wide configuration" in section 2.

<hr />

  </body>
</html>
Commit	Line	Data
	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
	2	<html>
	3	<head>
	4	<title>Linux Trace Toolkit Next Generation Manual</title>
	5	</head>
	6	<body>
	7
	8	<h1>Linux Trace Toolkit Next Generation Manual</h1>
	9
	10	Author : Mathieu Desnoyers, September 2005<br>
	11	Last update : January 21st, 2009<br>
	12	(originally known as the LTTng QUICKSTART guide)
	13
	14	<h2>Table of Contents</h2>
	15
	16	<ul>
	17	<li><a href="#intro" name="TOCintro">Introduction</a></li>
	18	<ul>
	19	<li><a href="#arch" name="TOCarch">Supported architectures</a></li>
	20	</ul>
	21
	22	<li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
	23	sources</a></li>
	24	<ul>
	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
	30	configuration</a>
	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>
	35
	36	<li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
	37	<ul>
	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>
	45	</ul>
	46
	47	<li><a href="#section3" name="TOCsection3">Adding kernel and user-space
	48	instrumentation</a>
	49	<ul>
	50	<li><a href="#kerneltp" name="TOCkerneltp">Adding kernel instrumentation</a></li>
	51	<li><a href="#usertp" name="TOCusertp">Adding userspace instrumentation</a></li>
	52	</ul>
	53
	54	<li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
	55	from LTTV</a></li>
	56	<ul>
	57	<li><a href="#pkgdebian" name="TOCpkgdebian">Create custom LTTV Debian
	58	<li><a href="#pkglttng" name="TOCpkglttng">Create custom LTTng packages</a></li>
	59	</ul>
	60
	61	</ul>
	62
	63	<hr />
	64
	65	<h2><a href="#TOCintro" name="intro">Introduction</a></h2>
	66	<p>
	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.
	73	<p>
	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
	78	refer to :
	79	<a
	80	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>
	81
	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
	86	kernel.
	87
	88	<br>
	89	<br>
	90	<h3><a href="#TOCarch" name="arch">Supported architectures</a></h3>
	91	<br>
	92	LTTng :<br>
	93	<br>
	94	<li> x86 32/64 bits
	95	<li> PowerPC 32 and 64 bits
	96	<li> ARM (with limited timestamping precision, e.g. 1HZ. Need
	97	architecture-specific support for better precision)
	98	<li> MIPS
	99	<li> sh (partial architecture-specific instrumentation)
	100	<li> sparc64 (partial architecture-specific instrumentation)
	101	<li> s390 (partial architecture-specific instrumentation)
	102	<li> Other architectures supported without architecture-specific instrumentation
	103	and with low-resolution timestamps.<br>
	104	<br>
	105	<br>
	106	LTTV :<br>
	107	<br>
	108	<li> Intel 32/64 bits
	109	<li> PowerPC 32 and 64 bits
	110	<li> Possibly others. Takes care of endianness and type size difference between
	111	the LTTng traces and the LTTV analysis tool.
	112
	113	<hr />
	114
	115
	116	<h2><a href="#TOCsection1" name="section1">Installation from sources</a></h2>
	117	<p>
	118
	119	<h3><a href="#TOCprerequisites" name="prerequisites">Prerequisites</a></h3>
	120	<ul>
	121	<p>
	122	Tools needed to follow the package download steps :
	123
	124	<li>wget
	125	<li>bzip2
	126	<li>gzip
	127	<li>tar
	128
	129	<p>
	130	You have to install the standard development libraries and programs necessary
	131	to compile a kernel :
	132
	133	<PRE>
	134	(from Documentation/Changes in the Linux kernel tree)
	135	Gnu C 2.95.3 # gcc --version
	136	Gnu make 3.79.1 # make --version
	137	binutils 2.12 # ld -v
	138	util-linux 2.10o # fdformat --version
	139	module-init-tools 0.9.10 # depmod -V
	140	</PRE>
	141
	142	<p>
	143	You might also want to have libncurses5 to have the text mode kernel
	144	configuration menu, but there are alternatives.
	145
	146	<p>
	147	Prerequisites for LTTV 0.x.x installation are :
	148
	149	<PRE>
	150	gcc 3.2 or better
	151	gtk 2.4 or better development libraries
	152	(Debian : libgtk2.0, libgtk2.0-dev)
	153	(Fedora : gtk2, gtk2-devel)
	154	note : For Fedora users : this might require at least core 3 from Fedora,
	155	or you might have to compile your own GTK2 library.
	156	glib 2.4 or better development libraries
	157	(Debian : libglib2.0-0, libglib2.0-dev)
	158	(Fedora : glib2, glib2-devel)
	159	libpopt development libraries
	160	(Debian : libpopt0, libpopt-dev)
	161	(Fedora : popt)
	162	libpango development libraries
	163	(Debian : libpango1.0, libpango1.0-dev)
	164	(Fedora : pango, pango-devel)
	165	libc6 development librairies
	166	(Debian : libc6, libc6-dev)
	167	(Fedora : glibc, glibc)
	168	</PRE>
	169	</ul>
	170
	171	<li>Reminder</li>
	172
	173	<p>
	174	See the list of compatibilities between LTTng, ltt-control and LTTV at :
	175	<a
	176	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
	177	versions compatibility</a>.
	178
	179
	180	<h3><a href="#TOCgetlttng" name="getlttng">Getting the LTTng packages</a></h3>
	181
	182	<PRE>
	183	su -
	184	mkdir /usr/src/lttng
	185	cd /usr/src/lttng
	186	(see http://ltt.polymtl.ca/lttng for package listing)
	187	wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
	188	bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 \| tar xvof -
	189	</PRE>
	190
	191
	192	<h3><a href="#TOCgetlttngsrc" name="getlttngsrc">Getting LTTng kernel sources</a></h3>
	193
	194	<PRE>
	195	su -
	196	cd /usr/src
	197	wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
	198	bzip2 -cd linux-2.6.X.tar.bz2 \| tar xvof -
	199	cd linux-2.6.X
	200	- For LTTng 0.9.4- cat /usr/src/lttng/patch-2.6.X-lttng-0.x.xx \| patch -p1
	201	- For LTTng 0.9.5+ apply the patches in the order specified in the series file,
	202	or use quilt
	203	cd ..
	204	mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
	205	</PRE>
	206
	207
	208	<h3><a href="#TOCinstalllttng" name="installlttng">Installing a LTTng kernel</a></h3>
	209
	210	<PRE>
	211	su -
	212	cd /usr/src/linux-2.6.X-lttng-0.x.xx
	213	make menuconfig (or make xconfig or make config)
	214	Select the < Help > button if you are not familiar with kernel
	215	configuration.
	216	Items preceded by [*] means they has to be built into the kernel.
	217	Items preceded by [M] means they has to be built as modules.
	218	Items preceded by [ ] means they should be removed.
	219	go to the "General setup" section
	220	Select the following options :
	221	[*] Prompt for development and/or incomplete code/drivers
	222	[*] Activate markers
	223	[*] Activate userspace markers ABI (experimental, optional)
	224	[*] Immediate value optimization (optional)
	225	[*] Linux Trace Toolkit Next Generation (LTTng) --->
	226	<M> or <*> Compile lttng tracing probes
	227	<M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
	228	<M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
	229	<M> or <*> Linux Trace Toolkit Serializer
	230	<M> or <*> Linux Trace Toolkit Marker Control
	231	<M> or <*> Linux Trace Toolkit Tracer
	232	[*] Align Linux Trace Toolkit Traces
	233	<M> or <*> Support logging events from userspace
	234	[*] Support trace extraction from crash dump
	235	<M> or <*> Linux Trace Toolkit Trace Controller
	236	<M> or <*> Linux Trace Toolkit State Dump
	237	Select <Exit>
	238	Select <Exit>
	239	Select <Yes>
	240	make
	241	make modules_install
	242	(if necessary, create a initrd with mkinitrd or your preferate alternative)
	243	(mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
	244
	245	-- on X86, X86_64
	246	make install
	247	reboot
	248	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	249
	250	-- on PowerPC
	251	cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
	252	cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
	253	cp .config /boot/config-2.6.X-lttng-0.x.xx
	254	depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	255	mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	256	(edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
	257	that comes first is the default kernel)
	258	ybin
	259	select the right entry at the yaboot prompt (see choices : tab, select : type
	260	the kernel name followed by enter)
	261	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	262	--
	263	</PRE>
	264
	265	<h3><a href="#TOCeditconfig" name="editconfig">Editing the system wide
	266	configuration</a></h3>
	267
	268	<p>
	269	You must activate debugfs and specify a mount point. This is typically done in
	270	fstab such that it happens at boot time. If you have never used DebugFS before,
	271	these operation would do this for you :
	272
	273	<PRE>
	274	mkdir /mnt/debugfs
	275	cp /etc/fstab /etc/fstab.lttng.bkp
	276	echo "debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
	277	</PRE>
	278
	279	<p>
	280	then, rebooting or issuing the following command will activate debugfs :
	281	<PRE>
	282	mount /mnt/debugfs
	283	</PRE>
	284
	285	<p>
	286	You need to load the LTT modules to be able to control tracing from user
	287	space. This is done by issuing the following commands. Note however
	288	these commands load all LTT modules. Depending on what options you chose to
	289	compile statically, you may not need to issue all these commands.
	290
	291	<PRE>
	292	modprobe ltt-trace-control
	293	modprobe ltt-marker-control
	294	modprobe ltt-tracer
	295	modprobe ltt-serialize
	296	modprobe ltt-relay
	297	modprobe ipc-trace
	298	modprobe kernel-trace
	299	modprobe mm-trace
	300	modprobe net-trace
	301	modprobe fs-trace
	302	modprobe jbd2-trace
	303	modprobe ext4-trace
	304	modprobe syscall-trace
	305	modprobe trap-trace
	306	#if locking tracing is wanted, uncomment the following
	307	#modprobe lockdep-trace
	308	</PRE>
	309
	310	<p>
	311	If you want to have complete information about the kernel state (including all
	312	the process names), you need to load the ltt-statedump module. This is done by
	313	issuing the command :
	314
	315	<PRE>
	316	modprobe ltt-statedump
	317	</PRE>
	318	<p>
	319	You can automate at boot time loading the ltt-control module by :
	320
	321	<PRE>
	322	cp /etc/modules /etc/modules.bkp
	323	echo ltt-trace-control >> /etc/modules
	324	echo ltt-marker-control >> /etc/modules
	325	echo ltt-tracer >> /etc/modules
	326	echo ltt-serialize >> /etc/modules
	327	echo ltt-relay >> /etc/modules
	328	echo ipc-trace >> /etc/modules
	329	echo kernel-trace >> /etc/modules
	330	echo mm-trace >> /etc/modules
	331	echo net-trace >> /etc/modules
	332	echo fs-trace >> /etc/modules
	333	echo jbd2-trace >> /etc/modules
	334	echo ext4-trace >> /etc/modules
	335	echo syscall-trace >> /etc/modules
	336	echo trap-trace >> /etc/modules
	337	#if locking tracing is wanted, uncomment the following
	338	#echo lockdep-trace >> /etc/modules
	339	</PRE>
	340
	341
	342	<h3><a href="#TOCgetlttctl" name="getlttctl">Getting and installing the
	343	ltt-control package (on the traced machine)</a></h3>
	344	<p>
	345	(note : the ltt-control package contains lttd and lttctl. Although it has the
	346	same name as the ltt-control kernel module, they are not the same thing.)
	347
	348	<PRE>
	349	su -
	350	cd /usr/src
	351	wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
	352	gzip -cd ltt-control-0.x-xxxx2008.tar.gz \| tar xvof -
	353	cd ltt-control-0.x-xxxx2006
	354	(refer to README to see the development libraries that must be installed on you
	355	system)
	356	./configure
	357	make
	358	make install
	359	</PRE>
	360
	361	<h3><a href="#TOCuserspacetracing" name="userspacetracing">Userspace tracing</a></h3>
	362
	363	<PRE>
	364	Make sure you selected the kernel menuconfig option :
	365	<M> or <*> Support logging events from userspace
	366	And that the ltt-userspace-event kernel module is loaded if selected as a
	367	module.
	368
	369	Simple userspace tracing is available through
	370	echo "some text to record" > /mnt/debugfs/ltt/write_event
	371
	372	It will appear in the trace under event :
	373	channel : userspace
	374	event name : event
	375	</PRE>
	376
	377	<h3><a href="#TOCgetlttv" name="getlttv">Getting and installing the LTTV package
	378	(on the visualisation machine, same
	379	or different from the visualisation machine)</a></h3>
	380
	381	<PRE>
	382	su -
	383	cd /usr/src
	384	wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
	385	gzip -cd lttv-0.x.xx-xxxx2008.tar.gz \| tar xvof -
	386	cd lttv-0.x.xx-xxxx2008
	387	(refer to README to see the development libraries that must be installed on your
	388	system)
	389	./configure
	390	make
	391	make install
	392	</PRE>
	393
	394	<hr />
	395
	396
	397	<h2><a href="#TOCsection2" name="section2">Using LTTng and LTTV</a></h2>
	398
	399	<li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing</b></li>
	400	<PRE>
	401	ltt-armall
	402	</PRE>
	403
	404	<h3><a href="#TOCuselttvgui" name="uselttvgui">Use graphical LTTV to control
	405	tracing and analyse traces</a></h3>
	406	<PRE>
	407	lttv-gui (or /usr/local/bin/lttv-gui)
	408	- Spot the "Tracing Control" icon : click on it
	409	(it's a traffic light icon)
	410	- enter the root password
	411	- click "start"
	412	- click "stop"
	413	- Yes
	414	* You should now see a trace
	415	</PRE>
	416
	417	<h3><a href="#TOCuselttngtext" name="uselttngtext">Use text mode LTTng to control tracing</a></h3>
	418	<PRE>
	419	The tracing can be controlled from a terminal by using the lttctl command (as
	420	root).
	421
	422	Start tracing :
	423
	424	lttctl -C -w /tmp/trace1 trace1
	425
	426	Stop tracing and destroy trace channels :
	427
	428	lttctl -D trace1
	429
	430	see lttctl --help for details.
	431	</PRE>
	432	<p>
	433	(note : to see if the buffers has been filled, look at the dmesg output after
	434	lttctl -D or after stopping tracing from the GUI, it will show an event lost
	435	count. If it is the case, try using larger buffers. See lttctl --help to learn
	436	how. lttv now also shows event lost messages in the console when loading a trace
	437	with missing events or lost subbuffers.)
	438
	439	<h3><a href="#TOCuselttvtext" name="uselttvtext">Use text mode LTTV</a></h3>
	440	<p>
	441	Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
	442	graphical plugins available.
	443	<p>
	444	For example, a simple trace dump in text format is available with :
	445	<PRE>
	446	lttv -m textDump -t /tmp/trace
	447	</PRE>
	448	<p>
	449	See lttv -m textDump --help for detailed command line options of textDump.
	450	<p>
	451	It is, in the current state of the project, very useful to use "grep" on the
	452	text output to filter by specific event fields. You can later copy the timestamp
	453	of the events to the clipboard and paste them in the GUI by clicking on the
	454	bottom right label "Current time". Support for this type of filtering should
	455	be added to the filter module soon.
	456
	457	<h3><a href="#TOChybrid" name="hybrid">Tracing in "Hybrid" mode</a></h3>
	458	<p>
	459	Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
	460	hybrid. It can be especially useful when studying big workloads on a long period
	461	of time.
	462	<p>
	463	When using this mode, the most important, low rate control information will be
	464	recorded during all the trace by lttd (i.e. process creation/exit). The high
	465	rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
	466	flight recorder buffer (now named flight-channelname_X).
	467	<p>
	468	The following lttctl commands take an hybrid trace :
	469	<p>
	470	Create trace channel, start lttd on normal channels, start tracing:
	471	<PRE>
	472	lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
	473	</PRE>
	474	<p>
	475	Stop tracing, start lttd on flight recorder channels, destroy trace channels :
	476	<PRE>
	477	lttctl -D -w /tmp/trace2 trace2
	478	</PRE>
	479	<p>
	480	Each "overwrite" channel is flight recorder channel.
	481
	482
	483	<h3><a href="#TOCflight" name="flight">Tracing in flight recorder mode</a></h3>
	484	<li>Flight recorder mode</li>
	485	<p>
	486	The flight recorder mode writes data into overwritten buffers for all channels,
	487	including control channels, except for the facilities tracefiles. It consists of
	488	setting all channels to "overwrite".
	489	<p>
	490	The following lttctl commands take a flight recorder trace :
	491	<PRE>
	492	lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
	493	...
	494	lttctl -D -w /tmp/trace3 trace3
	495	</PRE>
	496
	497	<hr />
	498
	499
	500	<h2><a href="#TOCsection3" name="section3">Adding new instrumentations with the
	501	markers</a></h2>
	502	<p>
	503
	504	<h3><a href="#TOCkerneltp" name="kerneltp">Adding kernel
	505	instrumentation</a></h3>
	506
	507	<p>
	508	See <a
	509	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>
	510	and <a
	511	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
	512	tree.
	513	<p>
	514	Also see <a
	515	href="http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/</a>
	516	for LTTng probe examples.
	517
	518	<h3><a href="#TOCusertp" name="usertp">Adding userspace instrumentation</a></h3>
	519
	520	Add new events to userspace programs with
	521	<a href="http://ltt.polymtl.ca/packages/">userspace markers packages</a>.
	522	Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
	523	allows inserting markers in executables and libraries, currently only on x86_32
	524	and x86_64.
	525	See <a
	526	href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.
	527
	528	<p>
	529	Note that a new design document for a 3rd generation of tracepoint/marker-based
	530	userspace tracing is available at <a
	531	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
	532	Design</a>. This new infrastructure is not yet implemented.
	533
	534	<p>
	535	The easy quick-and-dirty way to perform userspace tracing is currently to write
	536	an string to /mnt/debugfs/ltt/write_event. See <a
	537	href="#userspacetracing">Userspace tracing</a> in the
	538	installation for sources section of this document.
	539
	540	<hr />
	541
	542	<h2><a href="#TOCsection4" name="section4">Creating Debian or RPM packages</a></h2>
	543	<p>
	544
	545	<h3><a href="#TOCpkgdebian" name="pkgdebian">Create custom LTTV Debian packages</a></h3>
	546
	547	<PRE>
	548	Use : dpkg-buildpackage -rfakeroot
	549	</PRE>
	550	<p>
	551	You should then have your LTTV .deb files created for your architecture.
	552
	553	<h3><a href="#TOCpkglttng" name="pkglttng">Create custom LTTng packages</a></h3>
	554	<p>
	555	For building LTTng Debian packages :
	556	get the build tree with patches applies as explained in section 2.
	557
	558	<PRE>
	559	make menuconfig (or xconfig or config) (customize your configuration)
	560	make-kpkg kernel_image
	561	</PRE>
	562	<p>
	563	You will then see your freshly created .deb in /usr/src. Install it with
	564	<PRE>
	565	dpkg -i /usr/src/(image-name).deb
	566	</PRE>
	567	<p>
	568	Then, follow the section "Editing the system wide configuration" in section 2.
	569
	570	<hr />
	571
	572	</body>
	573	</html>