[lttv.git] / trunk / lttv / QUICKSTART.html

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<head>
  <title>Linux Trace Toolkit Quickstart</title>
</head>
  <body>

<h1>Linux Trace Toolkit Quickstart</h1>

Author : Mathieu Desnoyers, September 2005<br>
Last update : January 21st, 2009<br>

<h2>Table of Contents</h2>
<ul>

<li><a href="#intro" name="TOCintro">Introduction</a></li>
<li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
sources</a></li>
<li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
<li><a href="#section3" name="TOCsection3">Adding kernel and user-space
tracepoints</a></li>
<li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
from LTTV</a>

</ul>

<hr />

<h2><a href="#TOCintro" name="intro">Introduction</a></h2>
<p>
This document is made of four 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 lttng patch is necessary to have the tracing hooks in the kernel.

<br>
<br>
Supported architectures : 
<br>
LTTng :<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
<br>
<br>
LTTV :<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="#TOCsection2" name="section2">Installation from sources</a></h2>
<p>

<li>Prerequisites</li>
<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>.


<li>Getting the LTTng packages</li>

<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>


<li>Getting LTTng kernel sources</li>

<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>


<li>Installing a LTTng kernel</li>

<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>

<li>Editing the system wide configuration</li>

<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>

<li>Getting and installing the ltt-control package (on the traced machine)</li>
<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>

<li>Userspace tracing</li>

<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>

<li>Getting and installing the LTTV package (on the visualisation machine, same
or different from the visualisation machine)</li>

<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


<li>Getting and installing the markers-userspace package for user space
tracing (experimental)</li>
<p>
See <a
href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.

<hr />


<h2><a href="#TOCsection3" name="section3">Using LTTng and LTTV</a></h2>

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

<li>Use graphical LTTV to control tracing and analyse traces</li>
<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>

<li>Use text mode LTTng to control tracing</li>
<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 -R 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.)

<li>Use text mode LTTV</li>
<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.

<li>Hybrid mode</li>
<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.

<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>

**************************************************************
** Section 4 * Adding new instrumentations with the markers **
**************************************************************

See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
tree.

* Add new events to userspace programs with userspace markers
http://ltt.polymtl.ca/packages/

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.

***********************************************************
** Section 5 * Creating Debian or RPM packages           **
***********************************************************

* Create custom LTTV Debian packages

Use : dpkg-buildpackage -rfakeroot

You should then have your LTTV .deb files created for your architecture.

* Create custom LTTng packages

For building LTTng Debian packages :

Get the build tree with patches applies as explained in section 2.

make menuconfig (or xconfig or config) (customize your configuration)
make-kpkg kernel_image

You will then see your freshly created .deb in /usr/src. Install it with
dpkg -i /usr/src/(image-name).deb

Then, follow the section "Editing the system wide configuration" in section 2.


  </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 Quickstart</title>
	5	</head>
	6	<body>
	7
	8	<h1>Linux Trace Toolkit Quickstart</h1>
	9
	10	Author : Mathieu Desnoyers, September 2005<br>
	11	Last update : January 21st, 2009<br>
	12
	13	<h2>Table of Contents</h2>
	14	<ul>
	15
	16	<li><a href="#intro" name="TOCintro">Introduction</a></li>
	17	<li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
	18	sources</a></li>
	19	<li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
	20	<li><a href="#section3" name="TOCsection3">Adding kernel and user-space
	21	tracepoints</a></li>
	22	<li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
	23	from LTTV</a>
	24
	25	</ul>
	26
	27	<hr />
	28
	29	<h2><a href="#TOCintro" name="intro">Introduction</a></h2>
	30	<p>
	31	This document is made of four parts : the first one explains how
	32	to install LTTng and LTTV from sources, the second one describes the steps
	33	to follow to trace a system and view it. The third part explains
	34	briefly how to add a new trace point to the kernel and to user space
	35	applications. The fourth and last part explains how to create Debian or RPM
	36	packages from the LTTng and LTTV sources.
	37	<p>
	38	These operations are made for installing the LTTng 0.86 tracer on a linux 2.6.X
	39	kernel. You will also find instructions for installation of LTTV 0.12.x : the
	40	Linux Trace Toolkit Viewer.
	41	To see the list of compatibilities between LTTng, ltt-control, LTTV, please
	42	refer to :
	43	<a
	44	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>
	45	The lttng patch is necessary to have the tracing hooks in the kernel.
	46
	47	<br>
	48	<br>
	49	Supported architectures :
	50	<br>
	51	LTTng :<br>
	52	<li> x86 32/64 bits
	53	<li> PowerPC 32 and 64 bits
	54	<li> ARM (with limited timestamping precision, e.g. 1HZ. Need
	55	architecture-specific support for better precision)
	56	<li> MIPS
	57	<br>
	58	<br>
	59	LTTV :<br>
	60	<li> Intel 32/64 bits
	61	<li> PowerPC 32 and 64 bits
	62	<li> Possibly others. Takes care of endianness and type size difference between
	63	the LTTng traces and the LTTV analysis tool.
	64
	65	<hr />
	66
	67
	68	<h2><a href="#TOCsection2" name="section2">Installation from sources</a></h2>
	69	<p>
	70
	71	<li>Prerequisites</li>
	72	<ul>
	73	<p>
	74	Tools needed to follow the package download steps :
	75
	76	<li>wget
	77	<li>bzip2
	78	<li>gzip
	79	<li>tar
	80
	81	<p>
	82	You have to install the standard development libraries and programs necessary
	83	to compile a kernel :
	84
	85	<PRE>
	86	(from Documentation/Changes in the Linux kernel tree)
	87	Gnu C 2.95.3 # gcc --version
	88	Gnu make 3.79.1 # make --version
	89	binutils 2.12 # ld -v
	90	util-linux 2.10o # fdformat --version
	91	module-init-tools 0.9.10 # depmod -V
	92	</PRE>
	93
	94	<p>
	95	You might also want to have libncurses5 to have the text mode kernel
	96	configuration menu, but there are alternatives.
	97
	98	<p>
	99	Prerequisites for LTTV 0.x.x installation are :
	100
	101	<PRE>
	102	gcc 3.2 or better
	103	gtk 2.4 or better development libraries
	104	(Debian : libgtk2.0, libgtk2.0-dev)
	105	(Fedora : gtk2, gtk2-devel)
	106	note : For Fedora users : this might require at least core 3 from Fedora,
	107	or you might have to compile your own GTK2 library.
	108	glib 2.4 or better development libraries
	109	(Debian : libglib2.0-0, libglib2.0-dev)
	110	(Fedora : glib2, glib2-devel)
	111	libpopt development libraries
	112	(Debian : libpopt0, libpopt-dev)
	113	(Fedora : popt)
	114	libpango development libraries
	115	(Debian : libpango1.0, libpango1.0-dev)
	116	(Fedora : pango, pango-devel)
	117	libc6 development librairies
	118	(Debian : libc6, libc6-dev)
	119	(Fedora : glibc, glibc)
	120	</PRE>
	121	</ul>
	122
	123	<li>Reminder</li>
	124
	125	<p>
	126	See the list of compatibilities between LTTng, ltt-control and LTTV at :
	127	<a
	128	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
	129	versions compatibility</a>.
	130
	131
	132	<li>Getting the LTTng packages</li>
	133
	134	<PRE>
	135	su -
	136	mkdir /usr/src/lttng
	137	cd /usr/src/lttng
	138	(see http://ltt.polymtl.ca/lttng for package listing)
	139	wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
	140	bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 \| tar xvof -
	141	</PRE>
	142
	143
	144	<li>Getting LTTng kernel sources</li>
	145
	146	<PRE>
	147	su -
	148	cd /usr/src
	149	wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
	150	bzip2 -cd linux-2.6.X.tar.bz2 \| tar xvof -
	151	cd linux-2.6.X
	152	- For LTTng 0.9.4- cat /usr/src/lttng/patch-2.6.X-lttng-0.x.xx \| patch -p1
	153	- For LTTng 0.9.5+ apply the patches in the order specified in the series file,
	154	or use quilt
	155	cd ..
	156	mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
	157	</PRE>
	158
	159
	160	<li>Installing a LTTng kernel</li>
	161
	162	<PRE>
	163	su -
	164	cd /usr/src/linux-2.6.X-lttng-0.x.xx
	165	make menuconfig (or make xconfig or make config)
	166	Select the < Help > button if you are not familiar with kernel
	167	configuration.
	168	Items preceded by [*] means they has to be built into the kernel.
	169	Items preceded by [M] means they has to be built as modules.
	170	Items preceded by [ ] means they should be removed.
	171	go to the "General setup" section
	172	Select the following options :
	173	[*] Prompt for development and/or incomplete code/drivers
	174	[*] Activate markers
	175	[*] Activate userspace markers ABI (experimental, optional)
	176	[*] Immediate value optimization (optional)
	177	[*] Linux Trace Toolkit Next Generation (LTTng) --->
	178	<M> or <*> Compile lttng tracing probes
	179	<M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
	180	<M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
	181	<M> or <*> Linux Trace Toolkit Serializer
	182	<M> or <*> Linux Trace Toolkit Marker Control
	183	<M> or <*> Linux Trace Toolkit Tracer
	184	[*] Align Linux Trace Toolkit Traces
	185	<M> or <*> Support logging events from userspace
	186	[*] Support trace extraction from crash dump
	187	<M> or <*> Linux Trace Toolkit Trace Controller
	188	<M> or <*> Linux Trace Toolkit State Dump
	189	Select <Exit>
	190	Select <Exit>
	191	Select <Yes>
	192	make
	193	make modules_install
	194	(if necessary, create a initrd with mkinitrd or your preferate alternative)
	195	(mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
	196
	197	-- on X86, X86_64
	198	make install
	199	reboot
	200	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	201
	202	-- on PowerPC
	203	cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
	204	cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
	205	cp .config /boot/config-2.6.X-lttng-0.x.xx
	206	depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	207	mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	208	(edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
	209	that comes first is the default kernel)
	210	ybin
	211	select the right entry at the yaboot prompt (see choices : tab, select : type
	212	the kernel name followed by enter)
	213	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	214	--
	215	</PRE>
	216
	217	<li>Editing the system wide configuration</li>
	218
	219	<p>
	220	You must activate debugfs and specify a mount point. This is typically done in
	221	fstab such that it happens at boot time. If you have never used DebugFS before,
	222	these operation would do this for you :
	223
	224	<PRE>
	225	mkdir /mnt/debugfs
	226	cp /etc/fstab /etc/fstab.lttng.bkp
	227	echo "debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
	228	</PRE>
	229
	230	<p>
	231	then, rebooting or issuing the following command will activate debugfs :
	232	<PRE>
	233	mount /mnt/debugfs
	234	</PRE>
	235
	236	<p>
	237	You need to load the LTT modules to be able to control tracing from user
	238	space. This is done by issuing the following commands. Note however
	239	these commands load all LTT modules. Depending on what options you chose to
	240	compile statically, you may not need to issue all these commands.
	241
	242	<PRE>
	243	modprobe ltt-trace-control
	244	modprobe ltt-marker-control
	245	modprobe ltt-tracer
	246	modprobe ltt-serialize
	247	modprobe ltt-relay
	248	modprobe ipc-trace
	249	modprobe kernel-trace
	250	modprobe mm-trace
	251	modprobe net-trace
	252	modprobe fs-trace
	253	modprobe jbd2-trace
	254	modprobe ext4-trace
	255	modprobe syscall-trace
	256	modprobe trap-trace
	257	#if locking tracing is wanted, uncomment the following
	258	#modprobe lockdep-trace
	259	</PRE>
	260
	261	<p>
	262	If you want to have complete information about the kernel state (including all
	263	the process names), you need to load the ltt-statedump module. This is done by
	264	issuing the command :
	265
	266	<PRE>
	267	modprobe ltt-statedump
	268	</PRE>
	269	<p>
	270	You can automate at boot time loading the ltt-control module by :
	271
	272	<PRE>
	273	cp /etc/modules /etc/modules.bkp
	274	echo ltt-trace-control >> /etc/modules
	275	echo ltt-marker-control >> /etc/modules
	276	echo ltt-tracer >> /etc/modules
	277	echo ltt-serialize >> /etc/modules
	278	echo ltt-relay >> /etc/modules
	279	echo ipc-trace >> /etc/modules
	280	echo kernel-trace >> /etc/modules
	281	echo mm-trace >> /etc/modules
	282	echo net-trace >> /etc/modules
	283	echo fs-trace >> /etc/modules
	284	echo jbd2-trace >> /etc/modules
	285	echo ext4-trace >> /etc/modules
	286	echo syscall-trace >> /etc/modules
	287	echo trap-trace >> /etc/modules
	288	#if locking tracing is wanted, uncomment the following
	289	#echo lockdep-trace >> /etc/modules
	290	</PRE>
	291
	292	<li>Getting and installing the ltt-control package (on the traced machine)</li>
	293	<p>
	294	(note : the ltt-control package contains lttd and lttctl. Although it has the
	295	same name as the ltt-control kernel module, they are not the same thing.)
	296
	297	<PRE>
	298	su -
	299	cd /usr/src
	300	wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
	301	gzip -cd ltt-control-0.x-xxxx2008.tar.gz \| tar xvof -
	302	cd ltt-control-0.x-xxxx2006
	303	(refer to README to see the development libraries that must be installed on you
	304	system)
	305	./configure
	306	make
	307	make install
	308	</PRE>
	309
	310	<li>Userspace tracing</li>
	311
	312	<PRE>
	313	Make sure you selected the kernel menuconfig option :
	314	<M> or <*> Support logging events from userspace
	315	And that the ltt-userspace-event kernel module is loaded if selected as a
	316	module.
	317
	318	Simple userspace tracing is available through
	319	echo "some text to record" > /mnt/debugfs/ltt/write_event
	320
	321	It will appear in the trace under event :
	322	channel : userspace
	323	event name : event
	324	</PRE>
	325
	326	<li>Getting and installing the LTTV package (on the visualisation machine, same
	327	or different from the visualisation machine)</li>
	328
	329	<PRE>
	330	su -
	331	cd /usr/src
	332	wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
	333	gzip -cd lttv-0.x.xx-xxxx2008.tar.gz \| tar xvof -
	334	cd lttv-0.x.xx-xxxx2008
	335	(refer to README to see the development libraries that must be installed on your
	336	system)
	337	./configure
	338	make
	339	make install
	340
	341
	342	<li>Getting and installing the markers-userspace package for user space
	343	tracing (experimental)</li>
	344	<p>
	345	See <a
	346	href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.
	347
	348	<hr />
	349
	350
	351	<h2><a href="#TOCsection3" name="section3">Using LTTng and LTTV</a></h2>
	352
	353	<li>IMPORTANT : Arm Linux Kernel Markers after each boot</li>
	354	<PRE>
	355	ltt-armall
	356	</PRE>
	357
	358	<li>Use graphical LTTV to control tracing and analyse traces</li>
	359	<PRE>
	360	lttv-gui (or /usr/local/bin/lttv-gui)
	361	- Spot the "Tracing Control" icon : click on it
	362	(it's a traffic light icon)
	363	- enter the root password
	364	- click "start"
	365	- click "stop"
	366	- Yes
	367	* You should now see a trace
	368	</PRE>
	369
	370	<li>Use text mode LTTng to control tracing</li>
	371	<PRE>
	372	The tracing can be controlled from a terminal by using the lttctl command (as
	373	root).
	374
	375	Start tracing :
	376
	377	lttctl -C -w /tmp/trace1 trace1
	378
	379	Stop tracing and destroy trace channels :
	380
	381	lttctl -D trace1
	382
	383	see lttctl --help for details.
	384	<PRE>
	385	<p>
	386	(note : to see if the buffers has been filled, look at the dmesg output after
	387	lttctl -R or after stopping tracing from the GUI, it will show an event lost
	388	count. If it is the case, try using larger buffers. See lttctl --help to learn
	389	how. lttv now also shows event lost messages in the console when loading a trace
	390	with missing events or lost subbuffers.)
	391
	392	<li>Use text mode LTTV</li>
	393	<p>
	394	Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
	395	graphical plugins available.
	396	<p>
	397	For example, a simple trace dump in text format is available with :
	398	<PRE>
	399	lttv -m textDump -t /tmp/trace
	400	</PRE>
	401	<p>
	402	See lttv -m textDump --help for detailed command line options of textDump.
	403	<p>
	404	It is, in the current state of the project, very useful to use "grep" on the
	405	text output to filter by specific event fields. You can later copy the timestamp
	406	of the events to the clipboard and paste them in the GUI by clicking on the
	407	bottom right label "Current time". Support for this type of filtering should
	408	be added to the filter module soon.
	409
	410	<li>Hybrid mode</li>
	411	<p>
	412	Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
	413	hybrid. It can be especially useful when studying big workloads on a long period
	414	of time.
	415	<p>
	416	When using this mode, the most important, low rate control information will be
	417	recorded during all the trace by lttd (i.e. process creation/exit). The high
	418	rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
	419	flight recorder buffer (now named flight-channelname_X).
	420	<p>
	421	The following lttctl commands take an hybrid trace :
	422	<p>
	423	Create trace channel, start lttd on normal channels, start tracing:
	424	<PRE>
	425	lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
	426	</PRE>
	427	<p>
	428	Stop tracing, start lttd on flight recorder channels, destroy trace channels :
	429	<PRE>
	430	lttctl -D -w /tmp/trace2 trace2
	431	</PRE>
	432	<p>
	433	Each "overwrite" channel is flight recorder channel.
	434
	435	<li>Flight recorder mode</li>
	436	<p>
	437	The flight recorder mode writes data into overwritten buffers for all channels,
	438	including control channels, except for the facilities tracefiles. It consists of
	439	setting all channels to "overwrite".
	440	<p>
	441	The following lttctl commands take a flight recorder trace :
	442	<PRE>
	443	lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
	444	...
	445	lttctl -D -w /tmp/trace3 trace3
	446	</PRE>
	447
	448	**************************************************************
	449	** Section 4 * Adding new instrumentations with the markers **
	450	**************************************************************
	451
	452	See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
	453	tree.
	454
	455	* Add new events to userspace programs with userspace markers
	456	http://ltt.polymtl.ca/packages/
	457
	458	Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
	459	allows inserting markers in executables and libraries, currently only on x86_32
	460	and x86_64.
	461
	462	***********************************************************
	463	** Section 5 * Creating Debian or RPM packages **
	464	***********************************************************
	465
	466	* Create custom LTTV Debian packages
	467
	468	Use : dpkg-buildpackage -rfakeroot
	469
	470	You should then have your LTTV .deb files created for your architecture.
	471
	472	* Create custom LTTng packages
	473
	474	For building LTTng Debian packages :
	475
	476	Get the build tree with patches applies as explained in section 2.
	477
	478	make menuconfig (or xconfig or config) (customize your configuration)
	479	make-kpkg kernel_image
	480
	481	You will then see your freshly created .deb in /usr/src. Install it with
	482	dpkg -i /usr/src/(image-name).deb
	483
	484	Then, follow the section "Editing the system wide configuration" in section 2.
	485
	486
	487
	488	</body>
	489	</html>