[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
	38	<p>
	39	These operations are made for installing the LTTng 0.86 tracer on a linux 2.6.X
	40	kernel. You will also find instructions for installation of LTTV 0.12.x : the
	41	Linux Trace Toolkit Viewer.
	42	To see the list of compatibilities between LTTng, ltt-control, LTTV, please
	43	refer to :
	44	<a
	45	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>
	46	The lttng patch is necessary to have the tracing hooks in the kernel.
	47
	48	<br>
	49	<br>
	50	Supported architectures :
	51	<br>
	52	LTTng :<br>
	53	<li> x86 32/64 bits
	54	<li> PowerPC 32 and 64 bits
	55	<li> ARM (with limited timestamping precision, e.g. 1HZ. Need
	56	architecture-specific support for better precision)
	57	<li> MIPS
	58	<br>
	59	<br>
	60	LTTV :<br>
	61	<li> Intel 32/64 bits
	62	<li> PowerPC 32 and 64 bits
	63	<li> Possibly others. Takes care of endianness and type size difference between
	64	the LTTng traces and the LTTV analysis tool.
	65
	66	<hr />
	67
	68
	69	<h2><a href="#TOCsection2" name="section2">Installation from sources</a></h2>
	70	<p>
	71
	72	<li>Prerequisites</li>
	73	<ul>
	74	<p>
	75	Tools needed to follow the package download steps :
	76
	77	<li>wget
	78	<li>bzip2
	79	<li>gzip
	80	<li>tar
	81
	82	<p>
	83	You have to install the standard development libraries and programs necessary
	84	to compile a kernel :
	85
	86	<PRE>
	87	(from Documentation/Changes in the Linux kernel tree)
	88	Gnu C 2.95.3 # gcc --version
	89	Gnu make 3.79.1 # make --version
	90	binutils 2.12 # ld -v
	91	util-linux 2.10o # fdformat --version
	92	module-init-tools 0.9.10 # depmod -V
	93	</PRE>
	94
	95	<p>
	96	You might also want to have libncurses5 to have the text mode kernel
	97	configuration menu, but there are alternatives.
	98
	99	<p>
	100	Prerequisites for LTTV 0.x.x installation are :
	101
	102	<PRE>
	103	gcc 3.2 or better
	104	gtk 2.4 or better development libraries
	105	(Debian : libgtk2.0, libgtk2.0-dev)
	106	(Fedora : gtk2, gtk2-devel)
	107	note : For Fedora users : this might require at least core 3 from Fedora,
	108	or you might have to compile your own GTK2 library.
	109	glib 2.4 or better development libraries
	110	(Debian : libglib2.0-0, libglib2.0-dev)
	111	(Fedora : glib2, glib2-devel)
	112	libpopt development libraries
	113	(Debian : libpopt0, libpopt-dev)
	114	(Fedora : popt)
	115	libpango development libraries
	116	(Debian : libpango1.0, libpango1.0-dev)
	117	(Fedora : pango, pango-devel)
	118	libc6 development librairies
	119	(Debian : libc6, libc6-dev)
	120	(Fedora : glibc, glibc)
	121	</PRE>
	122	</ul>
	123
	124	<li>Reminder</li>
	125
	126	<p>
	127	See the list of compatibilities between LTTng, ltt-control and LTTV at :
	128	<a
	129	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
	130	versions compatibility</a>.
	131
	132
	133	<li>Getting the LTTng packages</li>
	134
	135	<PRE>
	136	su -
	137	mkdir /usr/src/lttng
	138	cd /usr/src/lttng
	139	(see http://ltt.polymtl.ca/lttng for package listing)
	140	wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
	141	bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 \| tar xvof -
	142	</PRE>
	143
	144
	145	<li>Getting LTTng kernel sources</li>
	146
	147	<PRE>
	148	su -
	149	cd /usr/src
	150	wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
	151	bzip2 -cd linux-2.6.X.tar.bz2 \| tar xvof -
	152	cd linux-2.6.X
	153	- For LTTng 0.9.4- cat /usr/src/lttng/patch-2.6.X-lttng-0.x.xx \| patch -p1
	154	- For LTTng 0.9.5+ apply the patches in the order specified in the series file,
	155	or use quilt
	156	cd ..
	157	mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
	158	</PRE>
	159
	160
	161	<li>Installing a LTTng kernel</li>
	162
	163	<PRE>
	164	su -
	165	cd /usr/src/linux-2.6.X-lttng-0.x.xx
	166	make menuconfig (or make xconfig or make config)
	167	Select the < Help > button if you are not familiar with kernel
	168	configuration.
	169	Items preceded by [*] means they has to be built into the kernel.
	170	Items preceded by [M] means they has to be built as modules.
	171	Items preceded by [ ] means they should be removed.
	172	go to the "General setup" section
	173	Select the following options :
	174	[*] Prompt for development and/or incomplete code/drivers
	175	[*] Activate markers
	176	[*] Activate userspace markers ABI (experimental, optional)
	177	[*] Immediate value optimization (optional)
	178	[*] Linux Trace Toolkit Next Generation (LTTng) --->
	179	<M> or <*> Compile lttng tracing probes
	180	<M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
	181	<M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
	182	<M> or <*> Linux Trace Toolkit Serializer
	183	<M> or <*> Linux Trace Toolkit Marker Control
	184	<M> or <*> Linux Trace Toolkit Tracer
	185	[*] Align Linux Trace Toolkit Traces
	186	<M> or <*> Support logging events from userspace
	187	[*] Support trace extraction from crash dump
	188	<M> or <*> Linux Trace Toolkit Trace Controller
	189	<M> or <*> Linux Trace Toolkit State Dump
	190	Select <Exit>
	191	Select <Exit>
	192	Select <Yes>
	193	make
	194	make modules_install
	195	(if necessary, create a initrd with mkinitrd or your preferate alternative)
	196	(mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
	197
	198	-- on X86, X86_64
	199	make install
	200	reboot
	201	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	202
	203	-- on PowerPC
	204	cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
	205	cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
	206	cp .config /boot/config-2.6.X-lttng-0.x.xx
	207	depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	208	mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
	209	(edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
	210	that comes first is the default kernel)
	211	ybin
	212	select the right entry at the yaboot prompt (see choices : tab, select : type
	213	the kernel name followed by enter)
	214	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
	215	--
	216	</PRE>
	217
	218	<li>Editing the system wide configuration</li>
	219
	220	<p>
	221	You must activate debugfs and specify a mount point. This is typically done in
	222	fstab such that it happens at boot time. If you have never used DebugFS before,
	223	these operation would do this for you :
	224
	225	<PRE>
	226	mkdir /mnt/debugfs
	227	cp /etc/fstab /etc/fstab.lttng.bkp
	228	echo "debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
	229	</PRE>
	230
	231	<p>
	232	then, rebooting or issuing the following command will activate debugfs :
	233	<PRE>
	234	mount /mnt/debugfs
	235	</PRE>
	236
	237	<p>
	238	You need to load the LTT modules to be able to control tracing from user
	239	space. This is done by issuing the following commands. Note however
	240	these commands load all LTT modules. Depending on what options you chose to
	241	compile statically, you may not need to issue all these commands.
	242
	243	<PRE>
	244	modprobe ltt-trace-control
	245	modprobe ltt-marker-control
	246	modprobe ltt-tracer
	247	modprobe ltt-serialize
	248	modprobe ltt-relay
	249	modprobe ipc-trace
	250	modprobe kernel-trace
	251	modprobe mm-trace
	252	modprobe net-trace
	253	modprobe fs-trace
	254	modprobe jbd2-trace
	255	modprobe ext4-trace
	256	modprobe syscall-trace
	257	modprobe trap-trace
	258	#if locking tracing is wanted, uncomment the following
	259	#modprobe lockdep-trace
	260	</PRE>
	261
	262	<p>
	263	If you want to have complete information about the kernel state (including all
	264	the process names), you need to load the ltt-statedump module. This is done by
	265	issuing the command :
	266
	267	<PRE>
	268	modprobe ltt-statedump
	269	</PRE>
	270	<p>
	271	You can automate at boot time loading the ltt-control module by :
	272
	273	<PRE>
	274	cp /etc/modules /etc/modules.bkp
	275	echo ltt-trace-control >> /etc/modules
	276	echo ltt-marker-control >> /etc/modules
	277	echo ltt-tracer >> /etc/modules
	278	echo ltt-serialize >> /etc/modules
	279	echo ltt-relay >> /etc/modules
	280	echo ipc-trace >> /etc/modules
	281	echo kernel-trace >> /etc/modules
	282	echo mm-trace >> /etc/modules
	283	echo net-trace >> /etc/modules
	284	echo fs-trace >> /etc/modules
	285	echo jbd2-trace >> /etc/modules
	286	echo ext4-trace >> /etc/modules
	287	echo syscall-trace >> /etc/modules
	288	echo trap-trace >> /etc/modules
	289	#if locking tracing is wanted, uncomment the following
	290	#echo lockdep-trace >> /etc/modules
	291	</PRE>
	292
	293	<li>Getting and installing the ltt-control package (on the traced machine)</li>
	294	<p>
	295	(note : the ltt-control package contains lttd and lttctl. Although it has the
	296	same name as the ltt-control kernel module, they are not the same thing.)
	297
	298	<PRE>
	299	su -
	300	cd /usr/src
	301	wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
	302	gzip -cd ltt-control-0.x-xxxx2008.tar.gz \| tar xvof -
	303	cd ltt-control-0.x-xxxx2006
	304	(refer to README to see the development libraries that must be installed on you
	305	system)
	306	./configure
	307	make
	308	make install
	309	</PRE>
	310
	311	<li>Userspace tracing</li>
	312
	313	<PRE>
	314	Make sure you selected the kernel menuconfig option :
	315	<M> or <*> Support logging events from userspace
	316	And that the ltt-userspace-event kernel module is loaded if selected as a
	317	module.
	318
	319	Simple userspace tracing is available through
	320	echo "some text to record" > /mnt/debugfs/ltt/write_event
	321
	322	It will appear in the trace under event :
	323	channel : userspace
	324	event name : event
	325	</PRE>
	326
	327	<li>Getting and installing the LTTV package (on the visualisation machine, same
	328	or different from the visualisation machine)</li>
	329
	330	<PRE>
	331	su -
	332	cd /usr/src
	333	wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
	334	gzip -cd lttv-0.x.xx-xxxx2008.tar.gz \| tar xvof -
	335	cd lttv-0.x.xx-xxxx2008
	336	(refer to README to see the development libraries that must be installed on your
	337	system)
	338	./configure
	339	make
	340	make install
	341
	342
	343	<li>Getting and installing the markers-userspace package for user space
	344	tracing (experimental)</li>
	345
	346	<p>
	347	See <a
	348	href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.
	349
	350	<hr />
	351
	352
	353	<h2><a href="#TOCsection3" name="section3">Using LTTng and LTTV</a></h2>
	354
	355	<li>IMPORTANT : Arm Linux Kernel Markers after each boot</li>
	356
	357	<PRE>
	358	ltt-armall
	359	</PRE>
	360
	361	<li>Use graphical LTTV to control tracing and analyse traces</li>
	362
	363	<PRE>
	364	lttv-gui (or /usr/local/bin/lttv-gui)
	365	- Spot the "Tracing Control" icon : click on it
	366	(it's a traffic light icon)
	367	- enter the root password
	368	- click "start"
	369	- click "stop"
	370	- Yes
	371	* You should now see a trace
	372	</PRE>
	373
	374	<li>Use text mode LTTng to control tracing</li>
	375
	376	<PRE>
	377	The tracing can be controlled from a terminal by using the lttctl command (as
	378	root).
	379
	380	Start tracing :
	381
	382	lttctl -C -w /tmp/trace1 trace1
	383
	384	Stop tracing and destroy trace channels :
	385
	386	lttctl -D trace1
	387
	388	see lttctl --help for details.
	389	<PRE>
	390
	391	<p>
	392	(note : to see if the buffers has been filled, look at the dmesg output after
	393	lttctl -R or after stopping tracing from the GUI, it will show an event lost
	394	count. If it is the case, try using larger buffers. See lttctl --help to learn
	395	how. lttv now also shows event lost messages in the console when loading a trace
	396	with missing events or lost subbuffers.)
	397
	398	<li>Use text mode LTTV</li>
	399
	400	<p>
	401	Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
	402	graphical plugins available.
	403
	404	<p>
	405	For example, a simple trace dump in text format is available with :
	406
	407	<PRE>
	408	lttv -m textDump -t /tmp/trace
	409	</PRE>
	410
	411	<p>
	412	See lttv -m textDump --help for detailed command line options of textDump.
	413
	414	<p>
	415	It is, in the current state of the project, very useful to use "grep" on the
	416	text output to filter by specific event fields. You can later copy the timestamp
	417	of the events to the clipboard and paste them in the GUI by clicking on the
	418	bottom right label "Current time". Support for this type of filtering should
	419	be added to the filter module soon.
	420
	421	<li>Hybrid mode</li>
	422
	423	<p>
	424	Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
	425	hybrid. It can be especially useful when studying big workloads on a long period
	426	of time.
	427
	428	<p>
	429	When using this mode, the most important, low rate control information will be
	430	recorded during all the trace by lttd (i.e. process creation/exit). The high
	431	rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
	432	flight recorder buffer (now named flight-channelname_X).
	433
	434	<p>
	435	The following lttctl commands take an hybrid trace :
	436	<p>
	437	Create trace channel, start lttd on normal channels, start tracing:
	438	<PRE>
	439	lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
	440	</PRE>
	441	<p>
	442	Stop tracing, start lttd on flight recorder channels, destroy trace channels :
	443	<PRE>
	444	lttctl -D -w /tmp/trace2 trace2
	445	</PRE>
	446	<p>
	447	Each "overwrite" channel is flight recorder channel.
	448
	449	<li>Flight recorder mode</li>
	450
	451	<p>
	452	The flight recorder mode writes data into overwritten buffers for all channels,
	453	including control channels, except for the facilities tracefiles. It consists of
	454	setting all channels to "overwrite".
	455
	456	<p>
	457	The following lttctl commands take a flight recorder trace :
	458
	459	<PRE>
	460	lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
	461	...
	462	lttctl -D -w /tmp/trace3 trace3
	463	</PRE>
	464
	465	**************************************************************
	466	** Section 4 * Adding new instrumentations with the markers **
	467	**************************************************************
	468
	469	See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
	470	tree.
	471
	472	* Add new events to userspace programs with userspace markers
	473	http://ltt.polymtl.ca/packages/
	474
	475	Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
	476	allows inserting markers in executables and libraries, currently only on x86_32
	477	and x86_64.
	478
	479	***********************************************************
	480	** Section 5 * Creating Debian or RPM packages **
	481	***********************************************************
	482
	483	* Create custom LTTV Debian packages
	484
	485	Use : dpkg-buildpackage -rfakeroot
	486
	487	You should then have your LTTV .deb files created for your architecture.
	488
	489	* Create custom LTTng packages
	490
	491	For building LTTng Debian packages :
	492
	493	Get the build tree with patches applies as explained in section 2.
	494
	495	make menuconfig (or xconfig or config) (customize your configuration)
	496	make-kpkg kernel_image
	497
	498	You will then see your freshly created .deb in /usr/src. Install it with
	499	dpkg -i /usr/src/(image-name).deb
	500
	501	Then, follow the section "Editing the system wide configuration" in section 2.
	502
	503
	504
	505	</body>
	506	</html>