Simple listing of lttng commands.
.SH "COMMANDS"
-.TP
-\fBadd-context\fP
-.nf
+.PP
+\fBadd-context\fP [OPTIONS]
+.RS
Add context to event(s) and/or channel(s).
A context is basically extra information appended to a channel. For instance,
counters (hardware branch misses and cache misses), to all events in the trace
data output:
-# lttng add-context \-k \-t prio \-t perf:branch-misses \-t perf:cache-misses
+.nf
+# lttng add-context \-k \-t prio \-t perf:branch-misses \\
+ \-t perf:cache-misses
+.fi
Please take a look at the help (\-h/\-\-help) for a detailed list of available
contexts.
If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-s, \-\-session NAME
- Apply on session name.
-\-c, \-\-channel NAME
- Apply on channel name.
-\-k, \-\-kernel
- Apply for the kernel tracer
-\-u, \-\-userspace
- Apply for the user-space tracer
-\-t, \-\-type TYPE
- Context type. You can repeat this option on the command line. Please
- use "lttng add-context \-h" to list all available types.
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-s, \-\-session NAME"
+Apply on session name.
+.TP
+.BR "\-c, \-\-channel NAME"
+Apply on channel name.
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.TP
+.BR "\-t, \-\-type TYPE"
+Context type. You can repeat this option on the command line. Please
+use "lttng add-context \-h" to list all available types.
+.RE
+.PP
-.IP "\fBcalibrate\fP"
-.nf
+.PP
+\fBcalibrate\fP [OPTIONS]
+.RS
Quantify LTTng overhead
The LTTng calibrate command can be used to find out the combined average
information (see lttng add-context \-\-help to see the list of available PMU
counters).
+.nf
# 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 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 start
# for a in $(seq 1 10); do \\
lttng calibrate \-\-kernel \-\-function;
done
# lttng destroy
-# babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* | tail \-n 1)
+# babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\
+ | tail \-n 1)
+.fi
The output from babeltrace can be saved to a text file and opened in a
spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between
The average result, for the i7, on 10 samples:
+.nf
Average Std.Dev.
perf_LLC_load_misses: 5.0 0.577
perf_LLC_store_misses: 1.6 0.516
perf_LLC_prefetch_misses: 9.0 14.742
+.fi
As we can notice, the load and store misses are relatively stable across runs
(their standard deviation is relatively low) compared to the prefetch misses.
accounted for quite precisely, but prefetches within a function seems to behave
too erratically (not much causality link between the code executed and the CPU
prefetch activity) to be accounted for.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-k, \-\-kernel
- Apply for the kernel tracer
-\-u, \-\-userspace
- Apply for the user-space tracer
-\-\-function
- Dynamic function entry/return probe (default)
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.TP
+.BR "\-\-function"
+Dynamic function entry/return probe (default)
+.RE
+.PP
-.IP "\fBcreate\fP [NAME] [OPTIONS]
-.nf
+.PP
+.IP \fBcreate\fP [NAME] [OPTIONS]
+.RS
Create tracing session.
A tracing session contains channel(s) which contains event(s). It is domain
The $HOME environment variable can be overridden by defining the environment
variable LTTNG_HOME. This is useful when the user running the commands has
a non-writeable home directory.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-o, \-\-output PATH
- Specify output path for traces
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-o, \-\-output PATH"
+Specify output path for traces
+.TP
+.BR "\-\-no-output"
+Traces will not be outputed
+.TP
+.BR "\-\-snapshot"
+Set the session in snapshot mode. Created in no-output mode and uses the
+URL, if one, as the default snapshot output. Every channel will be set
+in overwrite mode and with mmap output (splice not supported).
+.TP
+.BR "\-U, \-\-set-url=URL"
+Set URL for the consumer output destination. It is persistent for the
+session lifetime. Redo the command to change it. This will set both data
+and control URL for network.
+.TP
+.BR "\-C, \-\-ctrl-url=URL"
+Set control path URL. (Must use -D also)
+.TP
+.BR "\-D, \-\-data-url=URL"
+Set data path URL. (Must use -C also)
+.PP
Using these options, each API call can be controlled individually. For
instance, \-C does not enable the consumer automatically. You'll need the \-e
option for that.
-\-U, \-\-set-url=URL
- Set URL for the consumer output destination. It is persistent for the
- session lifetime. Redo the command to change it. This will set both
- data and control URL for network.
-\-C, \-\-ctrl-url=URL
- Set control path URL. (Must use -D also)
-\-D, \-\-data-url=URL
- Set data path URL. (Must use -C also)
-
.B URL FORMAT:
proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
Supported protocols are (proto):
-> file://...
- Local filesystem full path.
+.TP
+.BR "file://..."
+Local filesystem full path.
-> net://...
- This will use the default network transport layer which is TCP for both
- control (PORT1) and data port (PORT2). The default ports are
- respectively 5342 and 5343. Note that net[6]:// is not yet supported.
+.TP
+.BR "net://..."
+This will use the default network transport layer which is TCP for both
+control (PORT1) and data port (PORT2). The default ports are
+respectively 5342 and 5343. Note that net[6]:// is not yet supported.
-> tcp[6]://...
- Can only be used with -C and -D together
+.TP
+.BR "tcp[6]://..."
+Can only be used with -C and -D together
NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
.B EXAMPLES:
+.nf
# lttng create -U net://192.168.1.42
+.fi
Uses TCP and default ports for the given destination.
+.nf
# lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
+.fi
Uses TCP, default ports and IPv6.
+.nf
# lttng create s1 -U net://myhost.com:3229
-Create session s1 and set its consumer to myhost.com on port 3229 for control.
.fi
+Create session s1 and set its consumer to myhost.com on port 3229 for control.
+.RE
+.PP
-.IP
.IP "\fBdestroy\fP [OPTIONS] [NAME]"
.nf
.IP
+.IP "\fBsnapshot\fP ACTION"
+.nf
+Snapshot command for LTTng session.
+.fi
+
+.B OPTIONS:
+
+.nf
+\-h, \-\-help
+ Show summary of possible options and commands.
+\-\-list-options
+ Simple listing of options
+.fi
+
+.B ACTION:
+
+.nf
+\fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL>
+
+Setup and add an snapshot output for a session. Output are the destination
+where the snapshot will be sent. Only one output is permitted. To change it,
+you'll need to delete it and add back the new one.
+
+\fBdel-output\fP ID | NAME [-s <NAME>]
+
+Delete an output for a session using the ID. You can either specify the
+output's ID that can be found with list-output or the name.
+
+\fBlist-output\fP [-s <NAME>]
+
+List the output of a session. Attributes of the output are printed.
+
+\fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>]
+
+Snapshot a session's buffer(s) for all domains. If an URL is specified, it is
+used instead of a previously added output. Specifying only a name or/and a max
+size will override the current output values. For instance, you can record a
+snapshot with a custom maximum size or with a different name.
+
+$ lttng add-output -n mysnapshot file:///data/snapshot
+[...]
+$ lttng snapshot record -n new_name_snapshot
+
+The above will create a snapshot in /data/snapshot/new_name_snapshot* directory
+rather then in mysnapshot*/
+.fi
+
+.B LONG OPTIONS
+
+.nf
+\-s, \-\-session NAME
+ Apply to session name.
+\-n, \-\-name NAME
+ Name of the snapshot's output.
+\-m, \-\-max-size SIZE
+ Maximum size in bytes of the snapshot. The maxium size does not
+ include the metadata file.
+\-C, \-\-ctrl-url URL
+ Set control path URL. (Must use -D also)
+\-D, \-\-data-url URL
+ Set data path URL. (Must use -C also)
+.fi
+
+.IP
+
.IP "\fBstart\fP [NAME] [OPTIONS]"
.nf
Start tracing
projects / lttng-tools.git / blobdiff