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[Qemu-devel] [PULL 4/6] Update documentation for LTTng ust tracing
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 4/6] Update documentation for LTTng ust tracing |
Date: |
Wed, 19 Feb 2014 16:45:57 +0100 |
From: Mohamad Gebai <address@hidden>
Signed-off-by: Mohamad Gebai <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
docs/tracing.txt | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/docs/tracing.txt b/docs/tracing.txt
index bfc261b..bf2e15c 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -214,6 +214,42 @@ The "ust" backend uses the LTTng Userspace Tracer library.
There are no
monitor commands built into QEMU, instead UST utilities should be used to list,
enable/disable, and dump traces.
+Package lttng-tools is required for userspace tracing. You must ensure that the
+current user belongs to the "tracing" group, or manually launch the
+lttng-sessiond daemon for the current user prior to running any instance of
+QEMU.
+
+While running an instrumented QEMU, LTTng should be able to list all available
+events:
+
+ lttng list -u
+
+Create tracing session:
+
+ lttng create mysession
+
+Enable events:
+
+ lttng enable-event qemu:g_malloc -u
+
+Where the events can either be a comma-separated list of events, or "-a" to
+enable all tracepoint events. Start and stop tracing as needed:
+
+ lttng start
+ lttng stop
+
+View the trace:
+
+ lttng view
+
+Destroy tracing session:
+
+ lttng destroy
+
+Babeltrace can be used at any later time to view the trace:
+
+ babeltrace $HOME/lttng-traces/mysession-<date>-<time>
+
=== SystemTap ===
The "dtrace" backend uses DTrace sdt probes but has only been tested with
--
1.8.5.3
- [Qemu-devel] [PULL 0/6] Tracing patches, Stefan Hajnoczi, 2014/02/19
- [Qemu-devel] [PULL 1/6] Fix configure script for LTTng 2.x, Stefan Hajnoczi, 2014/02/19
- [Qemu-devel] [PULL 2/6] Modified the tracetool framework for LTTng 2.x, Stefan Hajnoczi, 2014/02/19
- [Qemu-devel] [PULL 4/6] Update documentation for LTTng ust tracing,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL 3/6] Adapt Makefiles to the new LTTng ust interface, Stefan Hajnoczi, 2014/02/19
- [Qemu-devel] [PULL 5/6] Add ust generated files to .gitignore, Stefan Hajnoczi, 2014/02/19
- [Qemu-devel] [PULL 6/6] trace-events: Fix typo in "offset", Stefan Hajnoczi, 2014/02/19
- Re: [Qemu-devel] [PULL 0/6] Tracing patches, Lluís Vilanova, 2014/02/19
- Re: [Qemu-devel] [PULL 0/6] Tracing patches, Peter Maydell, 2014/02/21