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

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<html>
<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>

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>.


* Getting the LTTng packages

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 -


* Getting LTTng kernel sources

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


* Installing a LTTng kernel

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.
--


* Editing the system wide configuration

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 :

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

then, rebooting or issuing the following command will activate debugfs :

mount /mnt/debugfs

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. 

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

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 :

modprobe ltt-statedump

You can automate at boot time loading the ltt-control module by :

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


* Getting and installing the ltt-control package (on the traced machine)
(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.)
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


* Userspace tracing

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


* Getting and installing the LTTV package (on the visualisation machine, same or
  different from the visualisation machine)

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


* Getting and installing the markers-userspace package for user space tracing
(experimental)
See http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2 or more recent.


***********************************************************
** Section 3 * Using LTTng and LTTV                      **
***********************************************************

* IMPORTANT : Arm Linux Kernel Markers after each boot

ltt-armall

* Use graphical LTTV to control tracing and analyse traces

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

* Use text mode LTTng to control tracing

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.

(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.)

* Use text mode LTTV

Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
graphical plugins available.

For example, a simple trace dump in text format is available with :

lttv -m textDump -t /tmp/trace

see lttv -m textDump --help for detailed command line options of textDump.

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.

* Hybrid mode

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.

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).

The following lttctl commands take an hybrid trace :

Create trace channel, start lttd on normal channels, start tracing:
lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2

Stop tracing, start lttd on flight recorder channels, destroy trace channels :
lttctl -D -w /tmp/trace2 trace2

Each "overwrite" channel is flight recorder channel.

* Flight recorder mode

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".

The following lttctl commands take a flight recorder trace :

lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
...
lttctl -D -w /tmp/trace3 trace3


**************************************************************
** 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
c924c2c6	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
c924c2c6	10	Author : Mathieu Desnoyers, September 2005<br>
24070967	11	Last update : January 21st, 2009<br>
	12
	13	<h2>Table of Contents</h2>
	14	<ul>
	15
f9ff56f3	16	<li><a href="#intro" name="TOCintro">Introduction</a></li>
24070967	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>
633bc4a3	22	<li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
633bc4a3	23	from LTTV</a>
c924c2c6	24
f9ff56f3	25	</ul>
	26
	27	<hr />
	28
b9e1fab1	29	<h2><a href="#TOCintro" name="intro">Introduction</a></h2>
c924c2c6	30	<p>
633bc4a3	31	This document is made of four parts : the first one explains how
24070967	32	to install LTTng and LTTV from sources, the second one describes the steps
633bc4a3	33	to follow to trace a system and view it. The third part explains
c924c2c6	34	briefly how to add a new trace point to the kernel and to user space
633bc4a3	35	applications. The fourth and last part explains how to create Debian or RPM
633bc4a3	36	packages from the LTTng and LTTV sources.
c924c2c6	37
c924c2c6	38	<p>
24070967	39	These operations are made for installing the LTTng 0.86 tracer on a linux 2.6.X
c924c2c6	40	kernel. You will also find instructions for installation of LTTV 0.12.x : the
c924c2c6	41	Linux Trace Toolkit Viewer.
24070967	42	To see the list of compatibilities between LTTng, ltt-control, LTTV, please
24070967	43	refer to :
c924c2c6	44	<a
c924c2c6	45	href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>
24070967	46	The lttng patch is necessary to have the tracing hooks in the kernel.
c924c2c6	47
24070967	48	<br>
24070967	49	<br>
633bc4a3	50	Supported architectures :
24070967	51	<br>
c924c2c6	52	LTTng :<br>
c924c2c6	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>
24070967	59	<br>
c924c2c6	60	LTTV :<br>
c924c2c6	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
f9ff56f3	66	<hr />
f9ff56f3	67
c924c2c6	68
633bc4a3	69	<h2><a href="#TOCsection2" name="section2">Installation from sources</a></h2>
633bc4a3	70	<p>
c924c2c6	71
633bc4a3	72	<li>Prerequisites</li>
	73	<ul>
	74	<p>
c924c2c6	75	Tools needed to follow the package download steps :
c924c2c6	76
633bc4a3	77	<li>wget
	78	<li>bzip2
	79	<li>gzip
	80	<li>tar
c924c2c6	81
633bc4a3	82	<p>
c924c2c6	83	You have to install the standard development libraries and programs necessary
	84	to compile a kernel :
	85
84cf5903	86	<PRE>
c924c2c6	87	(from Documentation/Changes in the Linux kernel tree)
84cf5903	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>
c924c2c6	94
633bc4a3	95	<p>
c924c2c6	96	You might also want to have libncurses5 to have the text mode kernel
	97	configuration menu, but there are alternatives.
	98
633bc4a3	99	<p>
c924c2c6	100	Prerequisites for LTTV 0.x.x installation are :
c924c2c6	101
84cf5903	102	<PRE>
	103	gcc 3.2 or better
	104	gtk 2.4 or better development libraries
c924c2c6	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.
84cf5903	109	glib 2.4 or better development libraries
c924c2c6	110	(Debian : libglib2.0-0, libglib2.0-dev)
c924c2c6	111	(Fedora : glib2, glib2-devel)
84cf5903	112	libpopt development libraries
c924c2c6	113	(Debian : libpopt0, libpopt-dev)
c924c2c6	114	(Fedora : popt)
84cf5903	115	libpango development libraries
c924c2c6	116	(Debian : libpango1.0, libpango1.0-dev)
c924c2c6	117	(Fedora : pango, pango-devel)
84cf5903	118	libc6 development librairies
c924c2c6	119	(Debian : libc6, libc6-dev)
c924c2c6	120	(Fedora : glibc, glibc)
84cf5903	121	</PRE>
633bc4a3	122	</ul>
c924c2c6	123
633bc4a3	124	<li>Reminder/<li>
c924c2c6	125
633bc4a3	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>.
c924c2c6	130
	131
	132	* Getting the LTTng packages
	133
	134	su -
	135	mkdir /usr/src/lttng
	136	cd /usr/src/lttng
	137	(see http://ltt.polymtl.ca/lttng for package listing)
	138	wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
	139	bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 \| tar xvof -
	140
	141
	142	* Getting LTTng kernel sources
	143
	144	su -
	145	cd /usr/src
	146	wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
	147	bzip2 -cd linux-2.6.X.tar.bz2 \| tar xvof -
	148	cd linux-2.6.X
	149	- For LTTng 0.9.4- cat /usr/src/lttng/patch-2.6.X-lttng-0.x.xx \| patch -p1
	150	- For LTTng 0.9.5+ apply the patches in the order specified in the series file,
	151	or use quilt
	152	cd ..
	153	mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
	154
	155
	156	* Installing a LTTng kernel
	157
	158	su -
	159	cd /usr/src/linux-2.6.X-lttng-0.x.xx
	160	make menuconfig (or make xconfig or make config)
	161	Select the < Help > button if you are not familiar with kernel
	162	configuration.
	163	Items preceded by [*] means they has to be built into the kernel.
	164	Items preceded by [M] means they has to be built as modules.
	165	Items preceded by [ ] means they should be removed.
	166	go to the "General setup" section
	167	Select the following options :
	168	[*] Prompt for development and/or incomplete code/drivers
	169	[*] Activate markers
	170	[*] Activate userspace markers ABI (experimental, optional)
	171	[*] Immediate value optimization (optional)
	172	[*] Linux Trace Toolkit Next Generation (LTTng) --->
	173	<M> or <*> Compile lttng tracing probes
	174	<M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
	175	<M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
	176	<M> or <*> Linux Trace Toolkit Serializer
	177	<M> or <*> Linux Trace Toolkit Marker Control
	178	<M> or <*> Linux Trace Toolkit Tracer
	179	[*] Align Linux Trace Toolkit Traces
	180	<M> or <*> Support logging events from userspace
	181	[*] Support trace extraction from crash dump
	182	<M> or <*> Linux Trace Toolkit Trace Controller
	183	<M> or <*> Linux Trace Toolkit State Dump
	184	Select <Exit>
	185	Select <Exit>
	186	Select <Yes>
	187	make
	188	make modules_install
	189	(if necessary, create a initrd with mkinitrd or your preferate alternative)
	190	(mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
	191
	192	-- on X86, X86_64
	193	make install
194	reboot
195	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
196
197	-- on PowerPC
198	cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
199	cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
200	cp .config /boot/config-2.6.X-lttng-0.x.xx
201	depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
202	mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
203	(edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
204	that comes first is the default kernel)
205	ybin
206	select the right entry at the yaboot prompt (see choices : tab, select : type
207	the kernel name followed by enter)
208	Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
209	--
210
211
212
213	* Editing the system wide configuration
214
215	You must activate debugfs and specify a mount point. This is typically done in
216	fstab such that it happens at boot time.
217
218	If you have never used DebugFS before, these operation would do this for you :
219
220	mkdir /mnt/debugfs
221	cp /etc/fstab /etc/fstab.lttng.bkp
222	echo "debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab
223
224	then, rebooting or issuing the following command will activate debugfs :
225
226	mount /mnt/debugfs
227
228	You need to load the LTT modules to be able to control tracing from user
229	space. This is done by issuing the following commands. Note however
230	these commands load all LTT modules. Depending on what options you chose to
231	compile statically, you may not need to issue all these commands.
232
233	modprobe ltt-trace-control
234	modprobe ltt-marker-control
235	modprobe ltt-tracer
236	modprobe ltt-serialize
237	modprobe ltt-relay
238	modprobe ipc-trace
239	modprobe kernel-trace
240	modprobe mm-trace
241	modprobe net-trace
242	modprobe fs-trace
243	modprobe jbd2-trace
244	modprobe ext4-trace
245	modprobe syscall-trace
246	modprobe trap-trace
247	#if locking tracing is wanted, uncomment the following
248	#modprobe lockdep-trace
249
250	If you want to have complete information about the kernel state (including all
251	the process names), you need to load the ltt-statedump module. This is done by
252	issuing the command :
253
254	modprobe ltt-statedump
255
256	You can automate at boot time loading the ltt-control module by :
257
258	cp /etc/modules /etc/modules.bkp
259	echo ltt-trace-control >> /etc/modules
260	echo ltt-marker-control >> /etc/modules
261	echo ltt-tracer >> /etc/modules
262	echo ltt-serialize >> /etc/modules
263	echo ltt-relay >> /etc/modules
264	echo ipc-trace >> /etc/modules
265	echo kernel-trace >> /etc/modules
266	echo mm-trace >> /etc/modules
267	echo net-trace >> /etc/modules
268	echo fs-trace >> /etc/modules
269	echo jbd2-trace >> /etc/modules
270	echo ext4-trace >> /etc/modules
271	echo syscall-trace >> /etc/modules
272	echo trap-trace >> /etc/modules
273	#if locking tracing is wanted, uncomment the following
274	#echo lockdep-trace >> /etc/modules
275
276
277	* Getting and installing the ltt-control package (on the traced machine)
278	(note : the ltt-control package contains lttd and lttctl. Although it has the
279	same name as the ltt-control kernel module, they are not the same thing.)
280	su -
281	cd /usr/src
282	wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
283	gzip -cd ltt-control-0.x-xxxx2008.tar.gz \| tar xvof -
284	cd ltt-control-0.x-xxxx2006
285	(refer to README to see the development libraries that must be installed on you
286	system)
287	./configure
288	make
289	make install
290
291
292	* Userspace tracing
293
294	Make sure you selected the kernel menuconfig option :
295	<M> or <*> Support logging events from userspace
296	And that the ltt-userspace-event kernel module is loaded if selected as a
297	module.
298
299	Simple userspace tracing is available through
300	echo "some text to record" > /mnt/debugfs/ltt/write_event
301
302	It will appear in the trace under event :
303	channel : userspace
304	event name : event
305
306
307	* Getting and installing the LTTV package (on the visualisation machine, same or
308	different from the visualisation machine)
309
310	su -
311	cd /usr/src
312	wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
313	gzip -cd lttv-0.x.xx-xxxx2008.tar.gz \| tar xvof -
314	cd lttv-0.x.xx-xxxx2008
315	(refer to README to see the development libraries that must be installed on your
316	system)
317	./configure
318	make
319	make install
320
321
322	* Getting and installing the markers-userspace package for user space tracing
323	(experimental)
324	See http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2 or more recent.
325
326
327
328	***********************************************************
329	** Section 3 * Using LTTng and LTTV **
330	***********************************************************
331
332	* IMPORTANT : Arm Linux Kernel Markers after each boot
333
334	ltt-armall
335
336	* Use graphical LTTV to control tracing and analyse traces
337
338	lttv-gui (or /usr/local/bin/lttv-gui)
339	- Spot the "Tracing Control" icon : click on it
340	(it's a traffic light icon)
341	- enter the root password
342	- click "start"
343	- click "stop"
344	- Yes
345	* You should now see a trace
346
347	* Use text mode LTTng to control tracing
348
349	The tracing can be controlled from a terminal by using the lttctl command (as
350	root).
351
352	Start tracing :
353
354	lttctl -C -w /tmp/trace1 trace1
355
356	Stop tracing and destroy trace channels :
357
358	lttctl -D trace1
359
360	see lttctl --help for details.
361
362	(note : to see if the buffers has been filled, look at the dmesg output after
363	lttctl -R or after stopping tracing from the GUI, it will show an event lost
364	count. If it is the case, try using larger buffers. See lttctl --help to learn
365	how. lttv now also shows event lost messages in the console when loading a trace
366	with missing events or lost subbuffers.)
367
368	* Use text mode LTTV
369
370	Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
371	graphical plugins available.
372
373	For example, a simple trace dump in text format is available with :
374
375	lttv -m textDump -t /tmp/trace
376
377	see lttv -m textDump --help for detailed command line options of textDump.
378
379	It is, in the current state of the project, very useful to use "grep" on the
380	text output to filter by specific event fields. You can later copy the timestamp
381	of the events to the clipboard and paste them in the GUI by clicking on the
382	bottom right label "Current time". Support for this type of filtering should
383	be added to the filter module soon.
384
385	* Hybrid mode
386
387	Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
388	hybrid. It can be especially useful when studying big workloads on a long period
389	of time.
390
391	When using this mode, the most important, low rate control information will be
392	recorded during all the trace by lttd (i.e. process creation/exit). The high
393	rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
394	flight recorder buffer (now named flight-channelname_X).
395
396	The following lttctl commands take an hybrid trace :
397
398	Create trace channel, start lttd on normal channels, start tracing:
399	lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
400
401	Stop tracing, start lttd on flight recorder channels, destroy trace channels :
402	lttctl -D -w /tmp/trace2 trace2
403
404	Each "overwrite" channel is flight recorder channel.
405
406	* Flight recorder mode
407
408	The flight recorder mode writes data into overwritten buffers for all channels,
409	including control channels, except for the facilities tracefiles. It consists of
410	setting all channels to "overwrite".
411
412	The following lttctl commands take a flight recorder trace :
413
414	lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
415	...
416	lttctl -D -w /tmp/trace3 trace3
417
418
419	**************************************************************
420	** Section 4 * Adding new instrumentations with the markers **
421	**************************************************************
422
423	See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
424	tree.
425
426	* Add new events to userspace programs with userspace markers
427	http://ltt.polymtl.ca/packages/
428
429	Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
430	allows inserting markers in executables and libraries, currently only on x86_32
431	and x86_64.
432
633bc4a3	433	***********************************************************
	434	** Section 5 * Creating Debian or RPM packages **
	435	***********************************************************
	436
	437	* Create custom LTTV Debian packages
	438
	439	Use : dpkg-buildpackage -rfakeroot
	440
	441	You should then have your LTTV .deb files created for your architecture.
	442
	443	* Create custom LTTng packages
	444
	445	For building LTTng Debian packages :
	446
	447	Get the build tree with patches applies as explained in section 2.
	448
	449	make menuconfig (or xconfig or config) (customize your configuration)
	450	make-kpkg kernel_image
	451
	452	You will then see your freshly created .deb in /usr/src. Install it with
	453	dpkg -i /usr/src/(image-name).deb
	454
	455	Then, follow the section "Editing the system wide configuration" in section 2.
	456
	457
	458
c924c2c6	459	</body>
c924c2c6	460	</html>