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Linux Trace Toolkit Next Generation or simply LTTng is based on the original Linux Trace Toolkit, but is a new development. It provides a tracing throughout the kernel with the minimum impact on system performances.

For more information about LTTng, please, visit http://ltt.polymtl.ca/ where there is a quickstart guide and some useful articles.

    STLinux LTTng Compatibility table
    STLinux Distribution Kernel version LTTng version ltt-control lttv
    2.2 Starting from the 2.6.17.14_40 0.9.5 (experimental version not fully tested) 0.41-13062007 LinuxTraceToolkitViewer-0.8.83-13062007
    2.3 Starting from the 2.6.23.1-105 0.10-pre14 0.45-11102007 lttv-0.10.0-pre1-15102007

Kernel configuration

The kernel configuration option is CONFIG_LTT. During the kernel configuration phase, in the Instrumentation Support sub-menu, it's possible to configure LTTng components as built-in(s) or as dynamic modules.

Using LTTng 0.10 version

LTTng applications (lttctl, lttv) have been already added in the STLinux distribution as RPM file.

Before starting, you need to activate debugfs and specify a mount point. In target rootFS, the following line must be added in the /etc/fstab file

    debugfs         /mnt/debugfs   debugfs  rw      0       0

The example below shows how to start and stop tracing:

    Start tracing
    #ltt-armall
#lttctl -n trace -d -l /mnt/debugfs/ltt -t /tmp/trace -Z 32768 -V 65536 -z 131072
    Stop tracing
    # lttctl -n trace -R
    Displaying the results
    On the target, you can dump in text mode format using the following command:

    # lttv -m textDump -t /tmp/trace

    Note: Linux Trace Toolkit Viewer (lttv) also provides a graphical interface GTK based (lttv-gui command).

Using old LTTng 0.9.5 version

See the official "Quickstart Guide" for more information.

Notes

  • LTTng host RPM packages and old versions of lttv and ltt-control are not distributed.
    Please download and install them from http://ltt.polymtl.ca/.