From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Wed, 29 Nov 2017 17:02:29 +0000 (-0500)
Subject: babeltrace-filter.lttng-utils.debug-info(7): fix LTTng prerequisites
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=a4c4205aa5847091494ce48fe8a78db1e36c8b68

babeltrace-filter.lttng-utils.debug-info(7): fix LTTng prerequisites

Add:

* Enable LTTng-UST state dump events.
* Enable LTTng-UST dynamic linker tracing helper events.

Convert some prose to procedures.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt b/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt
index 08820296..e640cdef 100644
--- a/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt
+++ b/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt
@@ -97,29 +97,58 @@ LTTng prerequisites
 A {comp} component can only analyze user space events generated by
 http://lttng.org[LTTng]{nbsp}2.8.0 or later.
 
-The filter component needs the LTTng-UST events to contain the
-`ip` and `vpid` fields in their context.
-
-To add those context fields with the man:lttng(1) command-line tool
-before the tracers are active (before `lttng start`):
+To get debugging information for LTTng-UST events which occur in
+executables and libraries which the system's loader loads (what
+you can see with man:ldd(1)):
 
+. Add the `ip` and `vpid` context fields to user space event records:
++
+--
 [role="term"]
 ----
 $ lttng add-context --userspace --type=ip --type=vpid
 ----
+--
++
+See man:lttng-add-context(1) for more details.
 
-See man:lttng-add-context(1) for more information.
+. Enable the LTTng-UST state dump events:
++
+--
+[role="term"]
+----
+$ lttng enable-event --userspace 'lttng_ust_statedump:*'
+----
+--
++
+See man:lttng-enable-event(1) and man:lttng-ust(3) for more details.
 
 To get debugging information for LTTng-UST events which occur in
-dynamically loaded objects, for example plugins, start the application
-to trace with the LTTng-UST dynamic linking helper:
+dynamically loaded objects, for example plugins:
 
+. Do the previous steps (add context fields and enable
+  the LTTng-UST state dump events).
+
+. Enable the LTTng-UST dynamic linker tracing helper events:
++
+--
 [role="term"]
 ----
-$ LD_PRELOAD=liblttng-ust-dl.so my-app
+$ lttng enable-event --userspace 'lttng_ust_dl:*'
 ----
+--
++
+See man:lttng-ust-dl(3) for more details.
 
-See man:lttng-ust-dl(3) for more information.
+. When you are ready to trace, start your application with the
+  `LD_PRELOAD` environment variable set to `liblttng-ust-dl.so`:
++
+--
+[role="term"]
+----
+$ LD_PRELOAD=liblttng-ust-dl.so my-app
+----
+--
 
 
 Separate debugging information