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
<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.
<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
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
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>
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
...