X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fquickstart.txt;h=f7ec99d373d166743fb39bdb6591c48dafd32c31;hb=ae8564917fa3cb3497ec17951d8ac0ee28de9c81;hp=e5e1f170565de2408d48b068824e76ce1926324e;hpb=e765105490394ee9f663c7c25d343b9146a023da;p=lttng-tools.git
diff --git a/doc/quickstart.txt b/doc/quickstart.txt
index e5e1f1705..f7ec99d37 100644
--- a/doc/quickstart.txt
+++ b/doc/quickstart.txt
@@ -1,82 +1,241 @@
+NOTES:
+--------------
+
+2011-12-12: For user-space tracing, only the global UST domain ("-u" alone) is
+supported meaning that if you enable a tracepoint for user-space it will be
+enabled for all applications for the current tracing session you are working
+on.
+
QUICKSTART
--------------
This is a quick start guide for the complete LTTng tool chain. This is divided
-in three sections respectively Kernel tracing, user-space tracing and reading a
+in three sections respectively kernel tracing, user-space tracing and reading a
trace.
See the README file for installation procedure or use the various Linux
distribution packages.
-In order to trace the Kernel, you'll need the lttng-modules >= 2.0 compiled and
-installed. See http://lttng.org/content/lttng-kernel-tracer for more
-instructions for that part. For user-space tracing, you'll need an instrumented
-application, please see http://lttng.org/ust
+In order to trace the kernel, you'll need the lttng-modules 2.0 compiled and
+installed. See http://lttng.org/lttng2.0 for more instructions for that part.
+For user-space tracing, you'll need an instrumented application with lttng-ust
+2.0.
-lttng-tools provide a session daemon (ltt-sessiond) that acts as a tracing
+lttng-tools provide a session daemon (lttng-sessiond) that acts as a tracing
registry. To trace any instrumented applications or the kernel, a registered
-tracing session is needed.
+tracing session is needed beforehand. To interact with the session daemon and a
+tracing session, you should use the lttng command line UI (lttng). It is also
+possible to use the liblttngctl library for tracing control (lttng.h).
+
+Here is a list of some powerful features the LTTng 2.0 kernel tracer offers:
-To interact with the session daemon and a tracing session, you can use the
-lttng command line UI (lttng).
+ * Kprobes support
+ * Function Tracer support
+ * Context information support (add context data to an event)
+ * Perf counter support
+ * Tracepoint support
-The next sections explain how to do tracing :)
+And for the LTTng UST 2.0 tracer:
+
+ * Applications registration
+ * Automatic tracepoints activation upon app. registration
+ * Context information support
+ * Safe buffers after application crash
+ * Per-user tracing (root access *not* mandatory)
+
+The next sections explains how to do tracing :)
Kernel Tracing
--------------
-You have to modprobe the lttng-modules manually or the session daemon will do
-it for you if they can be found on your system.
+You can start the session daemon by invoking the command "lttng-sessiond", or
+let the lttng command line tool do it for you. The session daemon loads the
+LTTng tracer modules for you if those modules can be found on your system. If
+they are not found, the kernel tracing feature will be unavailable.
-You can then start the session daemon by hand or the lttng command line tool
-will do it for you.
-
-List possible kernel events:
+List available kernel events:
# lttng list -k
-1) Create a tracing session. A .lttngrc will be created in $HOME containing
-the session name (here 'mysession') you are working on.
+1) Create a tracing session. The .lttng directory will be created with .lttngrc
+file in $HOME containing the session name (here 'mysession') you are working
+on.
# lttng create mysession
-2) Enable event(s). Here for example, we want only 'sched_switch' and
-'sys_enter' events for the kernel (-k/--kernel).
+If you have multiple sessions, you can change the current session by using
-# lttng enable-event sched_switch,sys_enter -k
+# lttng set-session myothersession
-or enable ALL events (-a/--all):
+2) Enable all tracepoints and all system call events.
# lttng enable-event -a -k
-3) Start tracing:
+3) Enable tracepoint event(s). Here for example, we want only
+'sched_switch' and 'sched_wakeup' events for the kernel (-k/--kernel).
+
+# lttng enable-event sched_switch,sched_wakeup -k
+
+or enable ALL tracepoint events:
+
+# lttng enable-event -a -k --tracepoint
+
+4) Enable all system call event(s).
+
+# lttng enable-event -a -k --syscall
+
+5) Enable kprobes and/or the function tracer with lttng
+
+This is a new feature made possible by the new LTTng 2.0 kernel tracer. You can
+enable a dynamic probe and data will be output in the trace along side with
+your tracing data.
+
+# lttng enable-event aname -k --probe symbol+0x0
+
+or
+
+# lttng enable-event aname -k --probe 0xffff7260695
+
+Either an
or a can be used for probes.
+
+You can also enable function tracer, which uses the Ftrace API (by Steven
+Rostedt). Again, data will be output in the trace.
+
+# lttng enable-event aname -k --function
+
+6) Enable context information for an event:
+
+This is also a new feature which allows you to add context information to an
+event. For example, you can add the PID along with the event information:
+
+# lttng add-context -k -e sched_switch -t pid
+
+At this point, you will have to look at 'lttng add-context --help' for all
+possible context type.
+
+You can on the same line activate multiple context:
+
+# lttng add-context -k -e sched_switch -t pid -t nice -t tid
+
+7) Enable perf counter for an event:
+
+Again, a new powerful feature is the possibility to add perf counter data
+(using the perf API by Ingo Molnar and Thomas Gleixner) to the trace on a per
+event basis. Let say we want to get the CPU cycles at each event:
+
+# lttng add-context -k -e sched_switch -t perf:cpu-cycles
+
+You'll have to use the add-context help for all possible perf counter values.
+
+8) Start tracing:
# lttng start
-Tracing is in progress at this point and will be written in
+Tracing is in progress at this point and traces will be written in
$HOME/lttng-traces/mysession--