(originally known as the LTTng QUICKSTART guide)
<h2>Table of Contents</h2>
-<ul>
+<ul>
<li><a href="#intro" name="TOCintro">Introduction</a></li>
+<ul>
+<li><a href="#arch" name="TOCarch">Supported architectures</a></li>
+</ul>
+
<li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
sources</a></li>
<ul>
ltt-control package</li>
<li><a href="#userspacetracing" name="TOCuserspacetracing">Userspace Tracing</li>
<li><a href="#getlttv" name="TOCgetlttv">Getting and installing the LTTV package</ul>
+
<li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
+<ul>
+<li><a href="#uselttvgui" name="TOCuselttvgui">Use graphical LTTV to control
+tracing and analyse traces</a></li>
+<li><a href="#uselttngtext" name="TOCuselttngtext">Use text mode LTTng to
+control tracing</a></li>
+<li><a href="#uselttvtext" name="TOCuselttvtext">Use text mode LTTV</a></li>
+<li><a href="#hybrid" name="TOChybrid">Tracing in "Hybrid" mode</a></li>
+<li><a href="#flight" name="TOCflight">Tracing in flight recorder mode</a></li>
+</ul>
+
<li><a href="#section3" name="TOCsection3">Adding kernel and user-space
instrumentation</a>
<ul>
<li><a href="#kerneltp" name="TOCkerneltp">Adding kernel instrumentation</a></li>
<li><a href="#usertp" name="TOCusertp">Adding userspace instrumentation</a></li>
</ul>
+
<li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
from LTTV</a></li>
<ul>
<li><a href="#pkgdebian" name="TOCpkgdebian">Create custom LTTV Debian
<li><a href="#pkglttng" name="TOCpkglttng">Create custom LTTng packages</a></li>
-
</ul>
+<li><a href="#section5" name="TOCsection5">Examples of LTTng use in the
+field</a></li>
+
</ul>
<hr />
<h2><a href="#TOCintro" name="intro">Introduction</a></h2>
<p>
-This document is made of four parts : the first one explains how
+This document is made of five parts : the first one explains how
to install LTTng and LTTV from sources, the second one describes the steps
to follow to trace a system and view it. The third part explains
briefly how to add a new trace point to the kernel and to user space
-applications. The fourth and last part explains how to create Debian or RPM
-packages from the LTTng and LTTV sources.
+applications. The fourth part explains how to create Debian or RPM
+packages from the LTTng and LTTV sources. The fifth and last part describes use
+of LTTng in the field.
<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
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.
+The ongoing work had the Linux Kernel Markers integrated in the mainline Linux
+kernel since Linux 2.6.24 and the Tracepoints since 2.6.28. In its current
+state, the lttng patchset is necessary to have the trace clocksource, the
+instrumentation and the LTTng high-speed data extraction mechanism added to the
+kernel.
+
+<br>
<br>
+<h3><a href="#TOCarch" name="arch">Supported architectures</a></h3>
<br>
-Supported architectures :
-br>
LTTng :<br>
+<br>
<li> x86 32/64 bits
<li> PowerPC 32 and 64 bits
<li> ARM (with limited timestamping precision, e.g. 1HZ. Need
architecture-specific support for better precision)
<li> MIPS
+<li> sh (partial architecture-specific instrumentation)
+<li> sparc64 (partial architecture-specific instrumentation)
+<li> s390 (partial architecture-specific instrumentation)
+<li> Other architectures supported without architecture-specific instrumentation
+and with low-resolution timestamps.<br>
<br>
<br>
LTTV :<br>
+<br>
<li> Intel 32/64 bits
<li> PowerPC 32 and 64 bits
<li> Possibly others. Takes care of endianness and type size difference between
<h2><a href="#TOCsection2" name="section2">Using LTTng and LTTV</a></h2>
-<li>IMPORTANT : Arm Linux Kernel Markers after each boot</li>
+<li><b>IMPORTANT : Arm Linux Kernel Markers after each boot before tracing</b></li>
<PRE>
ltt-armall
</PRE>
-<li>Use graphical LTTV to control tracing and analyse traces</li>
+<h3><a href="#TOCuselttvgui" name="uselttvgui">Use graphical LTTV to control
+tracing and analyse traces</a></h3>
<PRE>
lttv-gui (or /usr/local/bin/lttv-gui)
- Spot the "Tracing Control" icon : click on it
* You should now see a trace
</PRE>
-<li>Use text mode LTTng to control tracing</li>
+<h3><a href="#TOCuselttngtext" name="uselttngtext">Use text mode LTTng to control tracing</a></h3>
<PRE>
The tracing can be controlled from a terminal by using the lttctl command (as
root).
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>
+<h3><a href="#TOCuselttvtext" name="uselttvtext">Use text mode LTTV</a></h3>
<p>
Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
graphical plugins available.
bottom right label "Current time". Support for this type of filtering should
be added to the filter module soon.
-<li>Hybrid mode</li>
+<h3><a href="#TOChybrid" name="hybrid">Tracing in "Hybrid" mode</a></h3>
<p>
Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
hybrid. It can be especially useful when studying big workloads on a long period
<p>
Each "overwrite" channel is flight recorder channel.
+
+<h3><a href="#TOCflight" name="flight">Tracing in flight recorder mode</a></h3>
<li>Flight recorder mode</li>
<p>
The flight recorder mode writes data into overwritten buffers for all channels,
<p>
Then, follow the section "Editing the system wide configuration" in section 2.
+<hr />
+
+<h2><a href="#TOCsection5" name="section5">Examples of LTTng use in the field</a></h2>
+<p>
+A few examples of successful LTTng users :
+
+<ul>
+<li> Google are deploying LTTng on their servers. They want to use it to
+ monitor their production servers (with flight recorder mode tracing)
+ and to help them solve hard to reproduce problems. They have had
+ success with such tracing approach to fix "rare disk delay" issues and
+ VM-related issues presented in this article :
+<ul>
+ <li> <a href="http://ltt.polymtl.ca/papers/bligh-Reprint.pdf">Linux Kernel
+Debugging on Google-sized clusters at Ottawa Linux
+ Symposium 2007</a>
+</ul>
+<li> IBM Research have had problems with Commercial Scale-out applications,
+ which are being an increasing trend to split large server workloads.
+ They used LTTng successfully to solve a distributed filesystem-related
+ issue. It's presented in the same paper above.
+
+<li> Autodesk, in the development of their next-generation of Linux
+ audio/video edition applications, used LTTng extensively to solve
+ soft real-time issues they had. Also presented in the same paper.
+
+<li> Wind River included LTTng in their Linux distribution so their
+ clients, already familiar to Wind River own tracing solution in
+ VxWorks, car have the same kind of feature they have relied on for a
+ long time.
+<li> Montavista have integrated LTTng in their distribution for the same
+ reasons. It's used by Sony amongst others.
+<li> SuSE are currently integrating LTTng in their next SLES distribution,
+ because their clients asking for solutions which supports a kernel
+ closer to real-time need such tools to debug their problems.
+
+<li> A project between Ericsson, the Canadian Defense, NSERC and various
+ universities is just starting. It aims at monitoring and debugging
+ multi-core systems and provide automated and help user system behavior
+ analysis.
+
+<li> Siemens have been using LTTng internally for quite some time now.
+</ul>
</body>
</html>
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