+Linux Trace Toolkit Quickstart
+------------------------------
+Author : Mathieu Desnoyers, September 2005
+Last update : May 14, 2007
-QUICKSTART
-
-How to use LTTng and LTTV in a few lines :
-This document is made of four parts : The first one explains how to install
+This document is made of four parts : the first one explains how to install
LTTng and LTTV from Debian and RPM binary packages, the second one explains how
to install LTTng and LTTV from sources and the third one describes the steps
to follow to trace a system and view it. The fourth and last part explains
The following lttng patch is necessary to have the tracing hooks in the kernel.
The following ltt-control module controls the tracing.
-Required programs and librairies are assumed to be automatically installed in an
+Required programs and libraries are assumed to be automatically installed in an
installation with Debian or RPM packages. In the case of an installation from
sources, the dependencies are listed.
PowerPC 32 and 64 bits
-
-Author : Mathieu Desnoyers, September 2005
-Last update : May 30, 2006
-
-
***********************************************************
** Section 1 * Installation from Debian or RPM packages **
***********************************************************
-** NOTE : RPM and debian packages are only made once a version has been
+** NOTE : RPM and Debian packages are only made once a version has been
thoroughly tested. If they do not exist at the moment, please install from
sources (see section 2 below). To see the list of compatibilities between
LTTng, ltt-control, LTTV, genevent and lttng-modules, please refer to
package.
-* Install from Deb packages on Debian :
+* Install from .deb packages on Debian :
You can use the ltt.polymtl.ca apt source to get LTTV for Debian :
o gzip
o tar
-You have to install the standard development librairies and programs necessary
+You have to install the standard development libraries and programs necessary
to compile a kernel :
(from Documentation/Changes in the Linux kernel tree)
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
-cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1
+- 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
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 command :
+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-control
modprobe ltt-core
wget http://ltt.polymtl.ca/packages/LinuxTraceToolkitViewer-0.x.xx-xxxx2006.tar.gz
gzip -cd LinuxTraceToolkitViewer-0.x.xx-xxxx2006.tar.gz | tar xvof -
cd LinuxTraceToolkitViewer-0.x.xx-xxxx2006
-(refer to README to see the development libraries that must be installed on you
+(refer to README to see the development libraries that must be installed on your
system)
./configure
make
** Section 3 * Using LTTng and LTTV **
***********************************************************
+* 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)
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 -n tracename -d -l /mnt/relayfs/ltt -t /tmp/trace1 -m hybrid
+
+Stop tracing, start lttd on flight recorder channels, destroy trace channels :
+lttctl -n tracename -f -l /mnt/relayfs/ltt -t /tmp/trace1 -m hybrid
+
+
+We will need to tweak what we consider "important" medium rate events. For
+instance, thread branding events are actually considered a "high rate" event
+when it should be considered "medium rate". The same should apply for the
+state dump process enumeration.
+
+* Flight recorder mode
+
+The flight recorder mode writes data into overwritten buffers for all channels,
+including control channels, except for the facilities tracefiles.
+
+The following lttctl commands take a flight recorder trace :
+
+lttctl -n trace -c -m flight
+lttd -n -d -t /tmp/trace -c /sys/kernel/debug/ltt
+lttctl -n trace -s
+.. do stuff
+lttctl -n trace -q
+lttd -f -d -t /tmp/trace -c /sys/kernel/debug/ltt
+lttctl -m trace -r
+
***********************************************************
** Section 4 * Adding new instrumentations with genevent **
make install
-* Add new events to the kernel with genevent
+* Add new events to the kernel with genevent (deprecated in LTTng 0.9.x)
su -
cd /usr/local/share/ltt-control/facilities
will be connected to your marker and will typically call the logging
functions found in the header file you created with genevent.
-* Add new events to userspace programs with genevent
-See http://ltt.polymtl.ca/ > USERSPACE TRACING QUICKSTART
+* Add new kernel events
+*Important* note : in its current state, LTTng and LTTV needs the programmer
+to keep the marker/probe format string and the XML description of the
+event data types in sync by hand. Failure to do so will result in errors in
+LTTV.
+See the markers documentation to see how to describe the marker. You will need
+to clone probe modules found in ltt/probes to connect them to the markers so
+that the information can be recorded in the trace.
+* Add new events to userspace programs with genevent
+See http://ltt.polymtl.ca/ > USERSPACE TRACING QUICKSTART
+User-space tracing still uses genevent, which is subject to change in a near
+future.
projects / lttv.git / blobdiff