From Fedora Project Wiki

LTTng 2.0


Introduction of the new LTTng infrastructure including its userspace tracer component and the control tool.


  • Email: yannick.brosseau at

Current status

  • Targeted release: Fedora 18
  • Last updated: 2012-10-22
  • Percentage of completion: 100%
    • The tracing component are all present. The babeltrace viewer would have been nice to have, but still in RC upstream.

Detailed Description

The LTTng project aims at providing highly efficient tracing tools for Linux. Its tracers help tracking down performance issues and debugging problems involving multiple concurrent processes and threads. Tracing across multiple systems is also possible.

The LTTng 2.0 Tracer Toolchain allows integrated kernel and user-space tracing from a single user interface: the "lttng" command. The 2.0 kernel tracer can be manually built against a standard kernel. Other new features:

  • Produces CTF (Common Trace Format) natively (,
  • Emit SDT markers
  • See for the complete feature list
  • Allow multiple users and multiple sessions to trace simultaniously

Benefit to Fedora

Bringing the LTTng tracing capability to Fedora users. The lttng-ust library allows developper to instrument their application with static tracepoint. Other packages could be built with integrated ust tracepoint, allowing users to trace them without having to recompile them.


UST tracer and control package are already in place. The last part to add are the basic viewers.

How To Test

  1. Install the packages (mainly lttng-tools)
  2. For userspace tracing
    1. Compile one of the example in /usr/share/doc/lttng-ust/examples/
    2. Create, start a tracing session (
    3. Read the resulting trace

User Experience

New tool (lttng) will be available to manage the tracing.



Contingency Plan

All the tracer component are integrated. The only missing part is one or more viewer. So even without the viewer, it would still be possible to create a trace with the lttng tool. You will need an external tool to view your trace. (Work to package them are already underway)


Release Notes

  • Introduce LTTng 2.0 tracing tools

Comments and Discussion