-.TH "LTTNG" "1" "February 05th, 2014" "" ""
+.TH "LTTNG" "1" "May 13th, 2014" "" ""
.SH "NAME"
lttng \(em LTTng 2.x tracer control command line tool
A context is basically extra information appended to a channel. For instance,
you could ask the tracer to add the PID information for all events in a
channel. You can also add performance monitoring unit counters (perf PMU) using
-the perf kernel API).
+the perf kernel API.
-For example, this command will add the context information 'prio' and two perf
-counters (hardware branch misses and cache misses), to all events in the trace
+For example, this command will add the context information 'prio' and two per-CPU
+perf counters (hardware branch misses and cache misses), to all events in the trace
data output:
.nf
-# lttng add-context \-k \-t prio \-t perf:branch-misses \\
- \-t perf:cache-misses
+# lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\
+ \-t perf:cpu:cache-misses
.fi
Please take a look at the help (\-h/\-\-help) for a detailed list of available
contexts.
+Perf counters are available as per-CPU ("perf:cpu:...") and per-thread
+("perf:thread:...") counters. Currently, per-CPU counters can only be
+used with the kernel tracing domain, and per-thread counters can only be
+used with the UST tracing domain.
+
If no channel is given (\-c), the context is added to all channels that were
already enabled. If the session has no channel, a default channel is created.
Otherwise the context will be added only to the given channel (\-c).
# lttng create calibrate-function
# lttng enable-event calibrate \-\-kernel \\
\-\-function lttng_calibrate_kretprobe
-# lttng add-context \-\-kernel \-t perf:LLC-load-misses \\
- \-t perf:LLC-store-misses \\
- \-t perf:LLC-prefetch-misses
+# lttng add-context \-\-kernel \-t perf:cpu:LLC-load-misses \\
+ \-t perf:cpu:LLC-store-misses \\
+ \-t perf:cpu:LLC-prefetch-misses
# lttng start
# for a in $(seq 1 10); do \\
lttng calibrate \-\-kernel \-\-function;
in overwrite mode and with mmap output (splice not supported).
.TP
.BR "\-\-live [USEC]"
-Set the session exclusively in live mode. The paremeter is the delay in micro
+Set the session exclusively in live mode. The parameter is the delay in micro
seconds before the data is flushed and streamed. The live mode allows you to
stream the trace and view it while it's being recorded by any tracer. For that,
you need a lttng-relayd and this session requires a network URL (\-U or
Discard event when subbuffers are full (default)
.TP
.BR "\-\-overwrite"
-Flight recorder mode : overwrites events when subbuffers are full
+Flight recorder mode: overwrites events when subbuffers are full. The
+number of subbuffer must be 2 or more.
.TP
.BR "\-\-subbuf-size SIZE"
Subbuffer size in bytes {+k,+M,+G}.
.BR "\-C, \-\-tracefile-size SIZE"
Maximum size of each tracefile within a stream (in bytes).
0 means unlimited. (default: 0)
+Note: traces generated with this option may inaccurately report
+discarded events as of CTF 1.8.
.TP
.BR "\-W, \-\-tracefile-count COUNT"
Used in conjunction with \-C option, this will limit the number of files
'$ctx.vtid == 1234'
.fi
+Context information is available to all filters whether or not the add-context
+command has been used to add it to the event's channel, as long as the context
+field exists for that domain. For example, the filter examples given above will
+never fail to link: no add-context is required for the event's channel.
+
.TP
.BR "\-x, \-\-exclude LIST"
Add exclusions to UST tracepoints:
.RE
.PP
+.PP
+\fBload\fP [OPTIONS] [NAME]
+.RS
+Load tracing session configuration
+
+If NAME is omitted, all session configurations found in both the user's session
+configuration directory (default: ~/.lttng/sessions/) and the system session
+configuration directory (default: /etc/lttng/sessions/) will be loaded. Note
+that the sessions in the user directory are loaded first and then the system
+wide directory are loaded.
+
+.B OPTIONS:
+
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-a, \-\-all"
+Load all session configurations (default).
+.TP
+.BR "\-i, \-\-input-path PATH"
+Specify the input path for session configurations. This overrides the default
+session configuration directory.
+.TP
+.BR "\-f, -\-force"
+Overwrite current session configuration(s) if a session of the same name
+already exists.
+.RE
+.PP
+
+.PP
+\fBsave\fP [OPTIONS] [SESSION]
+.RS
+Save tracing session configuration
+
+If SESSION is omitted, all session configurations will be saved to individual
+\fB.lttng\fP files under the user's session configuration directory (default:
+~/.lttng/sessions/). The default session configuration file naming scheme is
+\fBSESSION.lttng\fP.
+
+For instance, a user in the tracing group saving a session from a root session
+daemon will save it in her/his user directory.
+
+.B OPTIONS:
+
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-a, \-\-all"
+Save all session configurations (default).
+.TP
+.BR "\-o, \-\-output-path PATH"
+Specify the output path for saved sessions. This overrides the default session
+configuration directory.
+.TP
+.BR "\-f, -\-force"
+Overwrite session configuration file if session name clashes.
+.RE
+.PP
+
.PP
\fBset-session\fP NAME [OPTIONS]
.RS
Name of the snapshot's output.
.TP
.BR "\-m, \-\-max-size SIZE"
-Maximum size in bytes of the snapshot. The maxium size does not include the
+Maximum size in bytes of the snapshot. The maximum size does not include the
metadata file. Human readable format is accepted: {+k,+M,+G}. For instance,
\-\-max-size 5M
.TP
tool. You can also use \-\-sessiond-path option having the same effect.
.PP
+.PP
+.IP "LTTNG_SESSION_CONFIG_XSD_PATH"
+Set the path in which the \fBsession.xsd\fP session configuration schema may be
+found.
+.PP
+
.SH "SEE ALSO"
.BR babeltrace(1),
.BR lttng-ust(3),
.PP
If you encounter any issues or usability problem, please report it on our
mailing list <lttng-dev@lists.lttng.org> to help improve this project or
-at https://bugs.lttng.org which is a bugtracker.
+at https://bugs.lttng.org which is a bug tracker.
.PP
.SH "CREDITS"
.PP
lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and
David Goulet. More people have since contributed to it. It is currently
-maintained by David Goulet <dgoulet@efficios.com>.
+maintained by Jérémie Galarneau <jeremie.galarneau@efficios.com>.
.PP
projects / lttng-tools.git / blobdiff