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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> ARMv7 OMAP3
<li> Other 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> ARMv7 OMAP3
	97	<li> Other ARM (with limited timestamping precision, e.g. 1HZ. Need
	98	architecture-specific support for better precision)
	99	<li> MIPS
	100	<li> sh (partial architecture-specific instrumentation)
	101	<li> sparc64 (partial architecture-specific instrumentation)
	102	<li> s390 (partial architecture-specific instrumentation)
	103	<li> Other architectures supported without architecture-specific instrumentation
	104	and with low-resolution timestamps.<br>
	105	<br>
	106	<br>
	107	LTTV :<br>
	108	<br>
	109	<li> Intel 32/64 bits
	110	<li> PowerPC 32 and 64 bits
	111	<li> Possibly others. Takes care of endianness and type size difference between
	112	the LTTng traces and the LTTV analysis tool.
	113
	114	<hr />
	115
	116
	117	<h2><a href="#TOCsection1" name="section1">Installation from sources</a></h2>
	118	<p>
	119
	120	<h3><a href="#TOCprerequisites" name="prerequisites">Prerequisites</a></h3>
	121	<ul>
	122	<p>
	123	Tools needed to follow the package download steps :
	124
	125	<li>wget
	126	<li>bzip2
	127	<li>gzip
	128	<li>tar
	129
	130	<p>
	131	You have to install the standard development libraries and programs necessary
	132	to compile a kernel :
	133
	134	<PRE>
	135	(from Documentation/Changes in the Linux kernel tree)
	136	Gnu C 2.95.3 # gcc --version
	137	Gnu make 3.79.1 # make --version
	138	binutils 2.12 # ld -v
	139	util-linux 2.10o # fdformat --version
	140	module-init-tools 0.9.10 # depmod -V
	141	</PRE>
	142
	143	<p>
	144	You might also want to have libncurses5 to have the text mode kernel
	145	configuration menu, but there are alternatives.
	146
	147	<p>
	148	Prerequisites for LTTV 0.x.x installation are :
	149
	150	<PRE>
	151	gcc 3.2 or better
	152	gtk 2.4 or better development libraries
	153	(Debian : libgtk2.0, libgtk2.0-dev)
	154	(Fedora : gtk2, gtk2-devel)
	155	note : For Fedora users : this might require at least core 3 from Fedora,
	156	or you might have to compile your own GTK2 library.
	157	glib 2.4 or better development libraries
	158	(Debian : libglib2.0-0, libglib2.0-dev)
	159	(Fedora : glib2, glib2-devel)
	160	libpopt development libraries
	161	(Debian : libpopt0, libpopt-dev)
	162	(Fedora : popt)
	163	libpango development libraries
	164	(Debian : libpango1.0, libpango1.0-dev)
	165	(Fedora : pango, pango-devel)
	166	libc6 development librairies
	167	(Debian : libc6, libc6-dev)
	168	(Fedora : glibc, glibc)
	169	</PRE>
	170	</ul>
	171
	172	<li>Reminder</li>
	173
	174	<p>
	175	See the list of compatibilities between LTTng, ltt-control and LTTV at :
	176	<a
	177	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
	178	versions compatibility</a>.
	179
	180
	181	<h3><a href="#TOCgetlttng" name="getlttng">Getting the LTTng packages</a></h3>
	182
	183	<PRE>
	184	su -
	185	mkdir /usr/src/lttng
	186	cd /usr/src/lttng
	187	(see http://ltt.polymtl.ca/lttng for package listing)
	188	wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
	189	bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 \| tar xvof -
	190	</PRE>
	191
	192
	193	<h3><a href="#TOCgetlttngsrc" name="getlttngsrc">Getting LTTng kernel sources</a></h3>
	194
	195	<PRE>
	196	su -
	197	cd /usr/src
	198	wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
	199	bzip2 -cd linux-2.6.X.tar.bz2 \| tar xvof -
	200	cd linux-2.6.X
	201	- For LTTng 0.9.4- cat /usr/src/lttng/patch-2.6.X-lttng-0.x.xx \| patch -p1
	202	- For LTTng 0.9.5+ apply the patches in the order specified in the series file,
	203	or use quilt
	204	cd ..
	205	mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
	206	</PRE>
	207
	208
	209	<h3><a href="#TOCinstalllttng" name="installlttng">Installing a LTTng kernel</a></h3>
	210
	211	<PRE>
	212	su -
	213	cd /usr/src/linux-2.6.X-lttng-0.x.xx
	214	make menuconfig (or make xconfig or make config)
	215	Select the < Help > button if you are not familiar with kernel
	216	configuration.
	217	Items preceded by [*] means they has to be built into the kernel.
	218	Items preceded by [M] means they has to be built as modules.
	219	Items preceded by [ ] means they should be removed.
	220	go to the "General setup" section
	221	Select the following options :
	222	[*] Prompt for development and/or incomplete code/drivers
	223	[*] Activate markers
	224	[*] Activate userspace markers ABI (experimental, optional)
	225	[*] Immediate value optimization (optional)
	226	[*] Linux Trace Toolkit Next Generation (LTTng) --->
	227	<M> or <*> Compile lttng tracing probes
	228	<M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
	229	<M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
	230	<M> or <*> Linux Trace Toolkit Serializer
	231	<M> or <*> Linux Trace Toolkit Marker Control
	232	<M> or <*> Linux Trace Toolkit Tracer
	233	[*] Align Linux Trace Toolkit Traces
	234	<M> or <*> Support logging events from userspace
	235	[*] Support trace extraction from crash dump
	236	<M> or <*> Linux Trace Toolkit Trace Controller
	237	<M> or <*> Linux Trace Toolkit State Dump
	238	Select <Exit>
	239	Select <Exit>
	240	Select <Yes>
	241	make
	242	make modules_install
	243	(if necessary, create a initrd with mkinitrd or your preferate alternative)
	244	(mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
	245
	246	-- on X86, X86_64
	247	make install
	248	reboot
	249	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	250
	251	-- on PowerPC
	252	cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
	253	cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
	254	cp .config /boot/config-2.6.X-lttng-0.x.xx
	255	depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	256	mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	257	(edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
	258	that comes first is the default kernel)
	259	ybin
	260	select the right entry at the yaboot prompt (see choices : tab, select : type
	261	the kernel name followed by enter)
	262	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	263	--
	264	</PRE>
	265
	266	<h3><a href="#TOCeditconfig" name="editconfig">Editing the system wide
	267	configuration</a></h3>
	268
	269	<p>
	270	You must activate debugfs and specify a mount point. This is typically done in
	271	fstab such that it happens at boot time. If you have never used DebugFS before,
	272	these operation would do this for you :
	273
	274	<PRE>
	275	mkdir /mnt/debugfs
	276	cp /etc/fstab /etc/fstab.lttng.bkp
	277	echo "debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
	278	</PRE>
	279
	280	<p>
	281	then, rebooting or issuing the following command will activate debugfs :
	282	<PRE>
	283	mount /mnt/debugfs
	284	</PRE>
	285
	286	<p>
	287	You need to load the LTT modules to be able to control tracing from user
	288	space. This is done by issuing the following commands. Note however
	289	these commands load all LTT modules. Depending on what options you chose to
	290	compile statically, you may not need to issue all these commands.
	291
	292	<PRE>
	293	modprobe ltt-trace-control
	294	modprobe ltt-marker-control
	295	modprobe ltt-tracer
	296	modprobe ltt-serialize
	297	modprobe ltt-relay
	298	modprobe ipc-trace
	299	modprobe kernel-trace
	300	modprobe mm-trace
	301	modprobe net-trace
	302	modprobe fs-trace
	303	modprobe jbd2-trace
	304	modprobe ext4-trace
	305	modprobe syscall-trace
	306	modprobe trap-trace
	307	#if locking tracing is wanted, uncomment the following
	308	#modprobe lockdep-trace
	309	</PRE>
	310
	311	<p>
	312	If you want to have complete information about the kernel state (including all
	313	the process names), you need to load the ltt-statedump module. This is done by
	314	issuing the command :
	315
	316	<PRE>
	317	modprobe ltt-statedump
	318	</PRE>
	319	<p>
	320	You can automate at boot time loading the ltt-control module by :
	321
	322	<PRE>
	323	cp /etc/modules /etc/modules.bkp
	324	echo ltt-trace-control >> /etc/modules
	325	echo ltt-marker-control >> /etc/modules
	326	echo ltt-tracer >> /etc/modules
	327	echo ltt-serialize >> /etc/modules
	328	echo ltt-relay >> /etc/modules
	329	echo ipc-trace >> /etc/modules
	330	echo kernel-trace >> /etc/modules
	331	echo mm-trace >> /etc/modules
	332	echo net-trace >> /etc/modules
	333	echo fs-trace >> /etc/modules
	334	echo jbd2-trace >> /etc/modules
	335	echo ext4-trace >> /etc/modules
	336	echo syscall-trace >> /etc/modules
	337	echo trap-trace >> /etc/modules
	338	#if locking tracing is wanted, uncomment the following
	339	#echo lockdep-trace >> /etc/modules
	340	</PRE>
	341
	342
	343	<h3><a href="#TOCgetlttctl" name="getlttctl">Getting and installing the
	344	ltt-control package (on the traced machine)</a></h3>
	345	<p>
	346	(note : the ltt-control package contains lttd and lttctl. Although it has the
	347	same name as the ltt-control kernel module, they are not the same thing.)
	348
	349	<PRE>
	350	su -
	351	cd /usr/src
	352	wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
	353	gzip -cd ltt-control-0.x-xxxx2008.tar.gz \| tar xvof -
	354	cd ltt-control-0.x-xxxx2006
	355	(refer to README to see the development libraries that must be installed on you
	356	system)
	357	./configure
	358	make
	359	make install
	360	</PRE>
	361
	362	<h3><a href="#TOCuserspacetracing" name="userspacetracing">Userspace tracing</a></h3>
	363
	364	<PRE>
	365	Make sure you selected the kernel menuconfig option :
	366	<M> or <*> Support logging events from userspace
	367	And that the ltt-userspace-event kernel module is loaded if selected as a
	368	module.
	369
	370	Simple userspace tracing is available through
	371	echo "some text to record" > /mnt/debugfs/ltt/write_event
	372
	373	It will appear in the trace under event :
	374	channel : userspace
	375	event name : event
	376	</PRE>
	377
	378	<h3><a href="#TOCgetlttv" name="getlttv">Getting and installing the LTTV package
	379	(on the visualisation machine, same
	380	or different from the visualisation machine)</a></h3>
	381
	382	<PRE>
	383	su -
	384	cd /usr/src
	385	wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
	386	gzip -cd lttv-0.x.xx-xxxx2008.tar.gz \| tar xvof -
	387	cd lttv-0.x.xx-xxxx2008
	388	(refer to README to see the development libraries that must be installed on your
	389	system)
	390	./configure
	391	make
	392	make install
	393	</PRE>
	394
	395	<hr />
	396
	397
	398	<h2><a href="#TOCsection2" name="section2">Using LTTng and LTTV</a></h2>
	399
	400	<li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing</b></li>
	401	<PRE>
	402	ltt-armall
	403	</PRE>
	404
	405	<h3><a href="#TOCuselttvgui" name="uselttvgui">Use graphical LTTV to control
	406	tracing and analyse traces</a></h3>
	407	<PRE>
	408	lttv-gui (or /usr/local/bin/lttv-gui)
	409	- Spot the "Tracing Control" icon : click on it
	410	(it's a traffic light icon)
	411	- enter the root password
	412	- click "start"
	413	- click "stop"
	414	- Yes
	415	* You should now see a trace
	416	</PRE>
	417
	418	<h3><a href="#TOCuselttngtext" name="uselttngtext">Use text mode LTTng to control tracing</a></h3>
	419	<PRE>
	420	The tracing can be controlled from a terminal by using the lttctl command (as
	421	root).
	422
	423	Start tracing :
	424
	425	lttctl -C -w /tmp/trace1 trace1
	426
	427	Stop tracing and destroy trace channels :
	428
	429	lttctl -D trace1
	430
	431	see lttctl --help for details.
	432	</PRE>
	433	<p>
	434	(note : to see if the buffers has been filled, look at the dmesg output after
	435	lttctl -D or after stopping tracing from the GUI, it will show an event lost
	436	count. If it is the case, try using larger buffers. See lttctl --help to learn
	437	how. lttv now also shows event lost messages in the console when loading a trace
	438	with missing events or lost subbuffers.)
	439
	440	<h3><a href="#TOCuselttvtext" name="uselttvtext">Use text mode LTTV</a></h3>
	441	<p>
	442	Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
	443	graphical plugins available.
	444	<p>
	445	For example, a simple trace dump in text format is available with :
	446	<PRE>
	447	lttv -m textDump -t /tmp/trace
	448	</PRE>
	449	<p>
	450	See lttv -m textDump --help for detailed command line options of textDump.
	451	<p>
	452	It is, in the current state of the project, very useful to use "grep" on the
	453	text output to filter by specific event fields. You can later copy the timestamp
	454	of the events to the clipboard and paste them in the GUI by clicking on the
	455	bottom right label "Current time". Support for this type of filtering should
	456	be added to the filter module soon.
	457
	458	<h3><a href="#TOChybrid" name="hybrid">Tracing in "Hybrid" mode</a></h3>
	459	<p>
	460	Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
	461	hybrid. It can be especially useful when studying big workloads on a long period
	462	of time.
	463	<p>
	464	When using this mode, the most important, low rate control information will be
	465	recorded during all the trace by lttd (i.e. process creation/exit). The high
	466	rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
	467	flight recorder buffer (now named flight-channelname_X).
	468	<p>
	469	The following lttctl commands take an hybrid trace :
	470	<p>
	471	Create trace channel, start lttd on normal channels, start tracing:
	472	<PRE>
	473	lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
	474	</PRE>
	475	<p>
	476	Stop tracing, start lttd on flight recorder channels, destroy trace channels :
	477	<PRE>
	478	lttctl -D -w /tmp/trace2 trace2
	479	</PRE>
	480	<p>
	481	Each "overwrite" channel is flight recorder channel.
	482
	483
	484	<h3><a href="#TOCflight" name="flight">Tracing in flight recorder mode</a></h3>
	485	<li>Flight recorder mode</li>
	486	<p>
	487	The flight recorder mode writes data into overwritten buffers for all channels,
	488	including control channels, except for the facilities tracefiles. It consists of
	489	setting all channels to "overwrite".
	490	<p>
	491	The following lttctl commands take a flight recorder trace :
	492	<PRE>
	493	lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
	494	...
	495	lttctl -D -w /tmp/trace3 trace3
	496	</PRE>
	497
	498	<hr />
	499
	500
	501	<h2><a href="#TOCsection3" name="section3">Adding new instrumentations with the
	502	markers</a></h2>
	503	<p>
	504
	505	<h3><a href="#TOCkerneltp" name="kerneltp">Adding kernel
	506	instrumentation</a></h3>
	507
	508	<p>
	509	See <a
	510	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>
	511	and <a
	512	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
	513	tree.
	514	<p>
	515	Also see <a
	516	href="http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/</a>
	517	for LTTng probe examples.
	518
	519	<h3><a href="#TOCusertp" name="usertp">Adding userspace instrumentation</a></h3>
	520
	521	Add new events to userspace programs with
	522	<a href="http://ltt.polymtl.ca/packages/">userspace markers packages</a>.
	523	Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
	524	allows inserting markers in executables and libraries, currently only on x86_32
	525	and x86_64.
	526	See <a
	527	href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.
	528
	529	<p>
	530	Note that a new design document for a 3rd generation of tracepoint/marker-based
	531	userspace tracing is available at <a
	532	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
	533	Design</a>. This new infrastructure is not yet implemented.
	534
	535	<p>
	536	The easy quick-and-dirty way to perform userspace tracing is currently to write
	537	an string to /mnt/debugfs/ltt/write_event. See <a
	538	href="#userspacetracing">Userspace tracing</a> in the
	539	installation for sources section of this document.
	540
	541	<hr />
	542
	543	<h2><a href="#TOCsection4" name="section4">Creating Debian or RPM packages</a></h2>
	544	<p>
	545
	546	<h3><a href="#TOCpkgdebian" name="pkgdebian">Create custom LTTV Debian packages</a></h3>
	547
	548	<PRE>
	549	Use : dpkg-buildpackage -rfakeroot
	550	</PRE>
	551	<p>
	552	You should then have your LTTV .deb files created for your architecture.
	553
	554	<h3><a href="#TOCpkglttng" name="pkglttng">Create custom LTTng packages</a></h3>
	555	<p>
	556	For building LTTng Debian packages :
	557	get the build tree with patches applies as explained in section 2.
	558
	559	<PRE>
	560	make menuconfig (or xconfig or config) (customize your configuration)
	561	make-kpkg kernel_image
	562	</PRE>
	563	<p>
	564	You will then see your freshly created .deb in /usr/src. Install it with
	565	<PRE>
	566	dpkg -i /usr/src/(image-name).deb
	567	</PRE>
	568	<p>
	569	Then, follow the section "Editing the system wide configuration" in section 2.
	570
	571	<hr />
	572
	573	</body>
	574	</html>