4 This is a quick start guide for the complete LTTng tool chain. This is divided
5 in three sections respectively Kernel tracing, user-space tracing and reading a
8 See the README file for installation procedure or use the various Linux
11 In order to trace the Kernel, you'll need the lttng-modules >= 2.0 compiled and
12 installed. See http://lttng.org/content/lttng-kernel-tracer for more
13 instructions for that part. For user-space tracing, you'll need an instrumented
14 application, please see http://lttng.org/ust
16 lttng-tools provide a session daemon (ltt-sessiond) that acts as a tracing
17 registry. To trace any instrumented applications or the kernel, a registered
18 tracing session is needed.
20 To interact with the session daemon and a tracing session, you can use the
21 lttng command line UI (lttng).
23 The next sections explain how to do tracing :)
28 You have to modprobe the lttng-modules manually or the session daemon will do
29 it for you if they can be found on your system.
31 You can then start the session daemon by hand or the lttng command line tool
34 List possible kernel events:
38 1) Create a tracing session. A .lttngrc will be created in $HOME containing
39 the session name (here 'mysession') you are working on.
41 # lttng create mysession
43 2) Enable event(s). Here for example, we want only 'sched_switch' and
44 'sys_enter' events for the kernel (-k/--kernel).
46 # lttng enable-event sched_switch,sys_enter -k
48 or enable ALL events (-a/--all):
50 # lttng enable-event -a -k
56 Tracing is in progress at this point and will be written in
57 $HOME/lttng-traces/mysession-<date>-<time>
63 5) Destroy your session after you are done with tracing
70 User-space tracer 2.0 not released at this point. You'll have to use 'ustctl'
71 to control user-space tracing.
76 To read your trace, you'll need babeltrace which will text dump your the trace.
77 Please see http://www.efficios.com/ctf and git tree
78 http://git.efficios.com/?p=babeltrace.git
80 # babeltrace -n $HOME/lttng-traces/mysession-<date>-<time> | less