Commit | Line | Data |
---|---|---|
391b9c72 | 1 | .TH "LTTNG" "1" "December 3rd, 2012" "" "" |
6991b181 DG |
2 | |
3 | .SH "NAME" | |
c5db699c | 4 | lttng \(em LTTng 2.x tracer control command line tool |
6991b181 DG |
5 | |
6 | .SH "SYNOPSIS" | |
7 | ||
8 | .PP | |
9 | .nf | |
10 | lttng [OPTIONS] <COMMAND> | |
11 | .fi | |
12 | .SH "DESCRIPTION" | |
13 | ||
14 | .PP | |
15 | The LTTng project aims at providing highly efficient tracing tools for Linux. | |
16 | It's tracers help tracking down performance issues and debugging problems | |
17 | involving multiple concurrent processes and threads. Tracing across multiple | |
18 | systems is also possible. | |
19 | ||
fa072eae | 20 | The \fBlttng\fP command line tool from the lttng-tools package is used to control |
6991b181 DG |
21 | both kernel and user-space tracing. Every interactions with the tracer should |
22 | be done by this tool or by the liblttng-ctl provided with the lttng-tools | |
23 | package. | |
24 | ||
25 | LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry, | |
50a3b92a | 26 | which allows you to interact with multiple tracers (kernel and user-space) |
6991b181 DG |
27 | inside the same container, a tracing session. Traces can be gathered from the |
28 | kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading | |
29 | those traces is done using the babeltrace(1) text viewer. | |
30 | ||
50a3b92a DG |
31 | We introduce the notion of \fBtracing domains\fP which is essentially a type of |
32 | tracer (kernel or user space for now). In the future, we could see a third | |
33 | tracer being for instance an hypervisor. For some commands, you'll need to | |
34 | specify on which domain the command applies (-u or -k). For instance, enabling | |
35 | a kernel event, you must specify the kernel domain to the command so we know | |
36 | for which tracer this event is for. | |
37 | ||
6991b181 DG |
38 | In order to trace the kernel, the session daemon needs to be running as root. |
39 | LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is | |
40 | in that group can interact with the root session daemon and thus trace the | |
41 | kernel. Session daemons can co-exist meaning that you can have a session daemon | |
fa072eae YB |
42 | running as Alice that can be used to trace her applications along side with a |
43 | root daemon or even a Bob daemon. We highly recommend to start the session | |
6991b181 DG |
44 | daemon at boot time for stable and long term tracing. |
45 | ||
46 | Every user-space applications instrumented with lttng-ust(3), will | |
47 | automatically register to the session daemon. This feature gives you the | |
48 | ability to list available traceable applications and tracepoints on a per user | |
49 | basis. (See \fBlist\fP command). | |
50 | .SH "OPTIONS" | |
51 | ||
52 | .PP | |
53 | This program follow the usual GNU command line syntax with long options starting with | |
54 | two dashes. Below is a summary of the available options. | |
55 | .PP | |
56 | ||
57 | .TP | |
c9e32613 | 58 | .BR "\-h, \-\-help" |
6991b181 DG |
59 | Show summary of possible options and commands. |
60 | .TP | |
c9e32613 | 61 | .BR "\-v, \-\-verbose" |
6991b181 | 62 | Increase verbosity. |
d829b38c | 63 | Three levels of verbosity are available which are triggered by putting additional v to |
fa072eae | 64 | the option (\-vv or \-vvv) |
6991b181 | 65 | .TP |
c9e32613 | 66 | .BR "\-q, \-\-quiet" |
6991b181 DG |
67 | Suppress all messages (even errors). |
68 | .TP | |
c9e32613 | 69 | .BR "\-g, \-\-group NAME" |
6991b181 DG |
70 | Set unix tracing group name. (default: tracing) |
71 | .TP | |
c9e32613 | 72 | .BR "\-n, \-\-no-sessiond" |
6991b181 DG |
73 | Don't automatically spawn a session daemon. |
74 | .TP | |
391b9c72 | 75 | .BR "\-\-sessiond\-path PATH" |
6991b181 DG |
76 | Set session daemon full binary path. |
77 | .TP | |
c9e32613 | 78 | .BR "\-\-list\-options" |
6991b181 DG |
79 | Simple listing of lttng options. |
80 | .TP | |
c9e32613 | 81 | .BR "\-\-list\-commands" |
6991b181 DG |
82 | Simple listing of lttng commands. |
83 | .SH "COMMANDS" | |
84 | ||
812a5eb7 | 85 | .PP |
6991b181 | 86 | \fBadd-context\fP |
812a5eb7 | 87 | .RS |
6991b181 DG |
88 | Add context to event(s) and/or channel(s). |
89 | ||
391b9c72 DG |
90 | A context is basically extra information appended to a channel. For instance, |
91 | you could ask the tracer to add the PID information for all events in a | |
92 | channel. You can also add performance monitoring unit counters (perf PMU) using | |
93 | the perf kernel API). | |
6991b181 DG |
94 | |
95 | For example, this command will add the context information 'prio' and two perf | |
96 | counters (hardware branch misses and cache misses), to all events in the trace | |
97 | data output: | |
98 | ||
812a5eb7 MD |
99 | .nf |
100 | # lttng add-context \-k \-t prio \-t perf:branch-misses \\ | |
101 | \-t perf:cache-misses | |
102 | .fi | |
6991b181 | 103 | |
c9e32613 | 104 | Please take a look at the help (\-h/\-\-help) for a detailed list of available |
6991b181 DG |
105 | contexts. |
106 | ||
bd337b98 DG |
107 | If no channel is given (\-c), the context is added to all channels that were |
108 | already enabled. If the session has no channel, a default channel is created. | |
109 | Otherwise the context will be added only to the given channel (\-c). | |
6991b181 | 110 | |
c9e32613 | 111 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 112 | file. |
6991b181 DG |
113 | |
114 | .B OPTIONS: | |
115 | ||
812a5eb7 MD |
116 | .TP |
117 | .BR "\-h, \-\-help" | |
118 | Show summary of possible options and commands. | |
119 | .TP | |
120 | .BR "\-s, \-\-session NAME" | |
121 | Apply on session name. | |
122 | .TP | |
123 | .BR "\-c, \-\-channel NAME" | |
124 | Apply on channel name. | |
125 | .TP | |
126 | .BR "\-k, \-\-kernel" | |
127 | Apply for the kernel tracer | |
128 | .TP | |
129 | .BR "\-u, \-\-userspace" | |
130 | Apply for the user-space tracer | |
131 | .TP | |
132 | .BR "\-t, \-\-type TYPE" | |
133 | Context type. You can repeat this option on the command line. Please | |
134 | use "lttng add-context \-h" to list all available types. | |
135 | .RE | |
136 | .PP | |
6991b181 DG |
137 | |
138 | .IP | |
139 | ||
140 | .IP "\fBcalibrate\fP" | |
141 | .nf | |
142 | Quantify LTTng overhead | |
143 | ||
144 | The LTTng calibrate command can be used to find out the combined average | |
145 | overhead of the LTTng tracer and the instrumentation mechanisms used. This | |
146 | overhead can be calibrated in terms of time or using any of the PMU performance | |
147 | counter available on the system. | |
148 | ||
149 | For now, the only calibration implemented is that of the kernel function | |
150 | instrumentation (kretprobes). | |
151 | ||
152 | * Calibrate kernel function instrumentation | |
153 | ||
154 | Let's use an example to show this calibration. We use an i7 processor with 4 | |
155 | general-purpose PMU registers. This information is available by issuing dmesg, | |
156 | looking for "generic registers". | |
157 | ||
158 | This sequence of commands will gather a trace executing a kretprobe hooked on | |
159 | an empty function, gathering PMU counters LLC (Last Level Cache) misses | |
c9e32613 | 160 | information (see lttng add-context \-\-help to see the list of available PMU |
6991b181 DG |
161 | counters). |
162 | ||
163 | # lttng create calibrate-function | |
c9e32613 DG |
164 | # lttng enable-event calibrate \-\-kernel \-\-function lttng_calibrate_kretprobe |
165 | # lttng add-context \-\-kernel \-t perf:LLC-load-misses \-t perf:LLC-store-misses \\ | |
166 | \-t perf:LLC-prefetch-misses | |
6991b181 DG |
167 | # lttng start |
168 | # for a in $(seq 1 10); do \\ | |
c9e32613 | 169 | lttng calibrate \-\-kernel \-\-function; |
6991b181 DG |
170 | done |
171 | # lttng destroy | |
c9e32613 | 172 | # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* | tail \-n 1) |
6991b181 DG |
173 | |
174 | The output from babeltrace can be saved to a text file and opened in a | |
175 | spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between | |
176 | consecutive "calibrate_entry" and "calibrate_return" events. Note that these | |
177 | counters are per-CPU, so scheduling events would need to be present to account | |
178 | for migration between CPU. Therefore, for calibration purposes, only events | |
179 | staying on the same CPU must be considered. | |
180 | ||
181 | The average result, for the i7, on 10 samples: | |
182 | ||
183 | Average Std.Dev. | |
184 | perf_LLC_load_misses: 5.0 0.577 | |
185 | perf_LLC_store_misses: 1.6 0.516 | |
186 | perf_LLC_prefetch_misses: 9.0 14.742 | |
187 | ||
188 | As we can notice, the load and store misses are relatively stable across runs | |
189 | (their standard deviation is relatively low) compared to the prefetch misses. | |
190 | We can conclude from this information that LLC load and store misses can be | |
191 | accounted for quite precisely, but prefetches within a function seems to behave | |
192 | too erratically (not much causality link between the code executed and the CPU | |
193 | prefetch activity) to be accounted for. | |
194 | .fi | |
195 | ||
196 | .B OPTIONS: | |
197 | ||
198 | .nf | |
c9e32613 | 199 | \-h, \-\-help |
6991b181 | 200 | Show summary of possible options and commands. |
c9e32613 | 201 | \-k, \-\-kernel |
6991b181 | 202 | Apply for the kernel tracer |
c9e32613 | 203 | \-u, \-\-userspace |
6991b181 | 204 | Apply for the user-space tracer |
c9e32613 | 205 | \-\-function |
6991b181 DG |
206 | Dynamic function entry/return probe (default) |
207 | .fi | |
208 | ||
209 | .IP | |
210 | ||
6b8f2e64 | 211 | .IP "\fBcreate\fP [NAME] [OPTIONS] |
6991b181 DG |
212 | .nf |
213 | Create tracing session. | |
214 | ||
215 | A tracing session contains channel(s) which contains event(s). It is domain | |
216 | agnostic meaning that you can enable channels and events for either the | |
217 | user-space tracer and/or the kernel tracer. It acts like a container | |
218 | aggregating multiple tracing sources. | |
219 | ||
220 | On creation, a \fB.lttngrc\fP file is created in your $HOME directory | |
221 | containing the current session name. If NAME is omitted, a session name is | |
fa072eae | 222 | automatically created having this form: 'auto-yyyymmdd-hhmmss'. |
6991b181 | 223 | |
c9e32613 | 224 | If no \fB\-o, \-\-output\fP is specified, the traces will be written in |
6991b181 | 225 | $HOME/lttng-traces. |
feb0f3e5 AM |
226 | |
227 | The $HOME environment variable can be overridden by defining the environment | |
228 | variable LTTNG_HOME. This is useful when the user running the commands has | |
229 | a non-writeable home directory. | |
6991b181 DG |
230 | .fi |
231 | ||
232 | .B OPTIONS: | |
233 | ||
234 | .nf | |
c9e32613 | 235 | \-h, \-\-help |
6991b181 | 236 | Show summary of possible options and commands. |
c9e32613 | 237 | \-\-list-options |
6991b181 | 238 | Simple listing of options |
c9e32613 | 239 | \-o, \-\-output PATH |
6991b181 | 240 | Specify output path for traces |
5dfe3327 MD |
241 | \-\-no-output |
242 | Traces will not be outputed | |
243 | \-\-snapshot | |
244 | Set the session in snapshot mode. Created in no-output mode | |
245 | and uses the URL, if one, as the default snapshot output. | |
246 | Every channel will be set in overwrite mode and with mmap | |
247 | output (splice not supported). | |
6b8f2e64 DG |
248 | |
249 | Using these options, each API call can be controlled individually. For | |
250 | instance, \-C does not enable the consumer automatically. You'll need the \-e | |
251 | option for that. | |
252 | ||
23d14dff | 253 | \-U, \-\-set-url=URL |
785d2d0d | 254 | Set URL for the consumer output destination. It is persistent for the |
6b8f2e64 DG |
255 | session lifetime. Redo the command to change it. This will set both |
256 | data and control URL for network. | |
257 | \-C, \-\-ctrl-url=URL | |
258 | Set control path URL. (Must use -D also) | |
259 | \-D, \-\-data-url=URL | |
260 | Set data path URL. (Must use -C also) | |
6b8f2e64 | 261 | |
785d2d0d DG |
262 | .B URL FORMAT: |
263 | ||
264 | proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] | |
265 | ||
266 | Supported protocols are (proto): | |
267 | > file://... | |
268 | Local filesystem full path. | |
269 | ||
270 | > net://... | |
271 | This will use the default network transport layer which is TCP for both | |
272 | control (PORT1) and data port (PORT2). The default ports are | |
273 | respectively 5342 and 5343. Note that net[6]:// is not yet supported. | |
274 | ||
275 | > tcp[6]://... | |
276 | Can only be used with -C and -D together | |
277 | ||
278 | NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732) | |
6b8f2e64 DG |
279 | |
280 | .B EXAMPLES: | |
281 | ||
282 | # lttng create -U net://192.168.1.42 | |
283 | Uses TCP and default ports for the given destination. | |
284 | ||
285 | # lttng create -U net6://[fe80::f66d:4ff:fe53:d220] | |
286 | Uses TCP, default ports and IPv6. | |
287 | ||
288 | # lttng create s1 -U net://myhost.com:3229 | |
289 | Create session s1 and set its consumer to myhost.com on port 3229 for control. | |
6991b181 DG |
290 | .fi |
291 | ||
292 | .IP | |
293 | ||
294 | .IP "\fBdestroy\fP [OPTIONS] [NAME]" | |
295 | .nf | |
296 | Teardown tracing session | |
297 | ||
298 | Free memory on the session daemon and tracer side. It's gone! | |
299 | ||
300 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
301 | .fi | |
302 | ||
303 | .B OPTIONS: | |
304 | ||
305 | .nf | |
c9e32613 | 306 | \-h, \-\-help |
6991b181 | 307 | Show summary of possible options and commands. |
a3c5b534 FG |
308 | \-a, \-\-all |
309 | Destroy all sessions | |
c9e32613 | 310 | \-\-list-options |
6991b181 DG |
311 | Simple listing of options |
312 | .fi | |
313 | ||
314 | .IP | |
315 | ||
316 | .IP "\fBenable-channel\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]" | |
317 | .nf | |
318 | Enable tracing channel | |
319 | ||
004f3466 DG |
320 | To enable an event, you must enable both the event and the channel that |
321 | contains it. | |
b883c01b | 322 | |
c9e32613 | 323 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 324 | file. |
7972aab2 DG |
325 | |
326 | It is important to note that if a certain type of buffers is used, the session | |
bd337b98 | 327 | will be set with that type and all other subsequent channel needs to have the |
7972aab2 | 328 | same type. |
bd337b98 | 329 | |
d2f11c4a DG |
330 | Note that once the session has been started and enabled on the tracer side, |
331 | it's not possible anymore to enable a new channel for that session. | |
6991b181 DG |
332 | .fi |
333 | ||
334 | .B OPTIONS: | |
335 | ||
336 | .nf | |
c9e32613 | 337 | \-h, \-\-help |
6991b181 | 338 | Show this help |
c9e32613 | 339 | \-\-list-options |
6991b181 | 340 | Simple listing of options |
391b9c72 | 341 | \-s, \-\-session NAME |
6991b181 | 342 | Apply on session name |
c9e32613 | 343 | \-k, \-\-kernel |
6991b181 | 344 | Apply to the kernel tracer |
c9e32613 | 345 | \-u, \-\-userspace |
6991b181 DG |
346 | Apply to the user-space tracer |
347 | ||
c9e32613 | 348 | \-\-discard |
6991b181 | 349 | Discard event when subbuffers are full (default) |
c9e32613 | 350 | \-\-overwrite |
6991b181 | 351 | Flight recorder mode : overwrites events when subbuffers are full |
391b9c72 | 352 | \-\-subbuf-size SIZE |
0a9c6494 DG |
353 | Subbuffer size in bytes {+k,+M,+G} |
354 | (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096) | |
1cb514ce | 355 | Rounded up to the next power of 2. |
bd337b98 DG |
356 | |
357 | The minimum subbuffer size, for each tracer, is the max value between | |
358 | the default above and the system page size. You can issue this command | |
359 | to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP | |
391b9c72 | 360 | \-\-num-subbuf NUM |
0a9c6494 | 361 | Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4, metadata: 2) |
1cb514ce | 362 | Rounded up to the next power of 2. |
391b9c72 | 363 | \-\-switch-timer USEC |
0a9c6494 DG |
364 | Switch subbuffer timer interval in µsec. |
365 | (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0) | |
391b9c72 | 366 | \-\-read-timer USEC |
0a9c6494 DG |
367 | Read timer interval in µsec. |
368 | (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0) | |
391b9c72 DG |
369 | \-\-output TYPE |
370 | Channel output type. Possible values: mmap, splice | |
0a9c6494 | 371 | (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap) |
7972aab2 DG |
372 | \-\-buffers-uid |
373 | Use per UID buffer (\-u only). Buffers are shared between applications | |
374 | that have the same UID. | |
375 | \-\-buffers-pid | |
376 | Use per PID buffer (\-u only). Each application has its own buffers. | |
377 | \-\-buffers-global | |
378 | Use shared buffer for the whole system (\-k only) | |
1624d5b7 | 379 | \-C, \-\-tracefile-size SIZE |
e132a0d4 | 380 | Maximum size of each tracefile within a stream (in bytes). |
0a9c6494 | 381 | 0 means unlimited. (default: 0) |
1624d5b7 JD |
382 | \-W, \-\-tracefile-count COUNT |
383 | Used in conjunction with \-C option, this will limit the number | |
0a9c6494 | 384 | of files created to the specified count. 0 means unlimited. (default: 0) |
1624d5b7 JD |
385 | |
386 | .B EXAMPLES: | |
387 | ||
388 | $ lttng enable-channel -C 4096 -W 32 chan1 | |
cea28771 DG |
389 | For each stream, the maximum size of each trace file will be 4096 bytes, and |
390 | there will be a maximum of 32 different files. The file count is appended after | |
1624d5b7 JD |
391 | the stream number as seen in the following example. The last trace file is |
392 | smaller than 4096 since it was not completely filled. | |
393 | ||
394 | ~/lttng-traces/[...]/chan1_0_0 (4096) | |
395 | ~/lttng-traces/[...]/chan1_0_1 (4096) | |
396 | ~/lttng-traces/[...]/chan1_0_2 (3245) | |
397 | ~/lttng-traces/[...]/chan1_1_0 (4096) | |
398 | ... | |
399 | ||
400 | $ lttng enable-channel -C 4096 | |
401 | This will create trace files of 4096 bytes and will create new ones as long as | |
402 | there is data available. | |
6991b181 DG |
403 | .fi |
404 | ||
405 | .IP | |
406 | ||
407 | .IP "\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]" | |
408 | .nf | |
409 | Enable tracing event | |
410 | ||
c9e32613 | 411 | A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is |
6991b181 | 412 | omitted, a default channel named '\fBchannel0\fP' is created and the event is |
c9e32613 | 413 | added to it. For the user-space tracer, using \fB\-a, \-\-all\fP is the same as |
6991b181 DG |
414 | using the wildcard "*". |
415 | ||
c9e32613 | 416 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 DG |
417 | file. |
418 | .fi | |
419 | ||
420 | .B OPTIONS: | |
421 | ||
422 | .nf | |
c9e32613 | 423 | \-h, \-\-help |
6991b181 | 424 | Show summary of possible options and commands. |
c9e32613 | 425 | \-\-list-options |
6991b181 | 426 | Simple listing of options |
391b9c72 | 427 | \-s, \-\-session NAME |
6991b181 | 428 | Apply on session name |
391b9c72 | 429 | \-c, \-\-channel NAME |
6991b181 | 430 | Apply on channel name |
c9e32613 | 431 | \-a, \-\-all |
c5650942 DG |
432 | Enable all tracepoints and syscalls. This actually enable a single |
433 | wildcard event "*". | |
c9e32613 | 434 | \-k, \-\-kernel |
6991b181 | 435 | Apply for the kernel tracer |
c9e32613 | 436 | \-u, \-\-userspace |
6991b181 DG |
437 | Apply for the user-space tracer |
438 | ||
c9e32613 | 439 | \-\-tracepoint |
6991b181 DG |
440 | Tracepoint event (default) |
441 | - userspace tracer supports wildcards at end of string. Don't forget to | |
442 | quote to deal with bash expansion. | |
443 | e.g.: | |
444 | "*" | |
445 | "app_component:na*" | |
391b9c72 DG |
446 | \-\-loglevel NAME |
447 | Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h). | |
448 | \-\-loglevel-only NAME | |
449 | Tracepoint loglevel (only this loglevel). | |
450 | ||
451 | The loglevel or loglevel-only options should be combined with a | |
452 | tracepoint name or tracepoint wildcard. | |
c9e32613 | 453 | \-\-probe [addr | symbol | symbol+offset] |
6991b181 DG |
454 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) |
455 | or hexadecimal (0xNNN...) | |
c9e32613 | 456 | \-\-function [addr | symbol | symbol+offset] |
6991b181 DG |
457 | Dynamic function entry/return probe. Addr and offset can be octal |
458 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) | |
c9e32613 | 459 | \-\-syscall |
6b8f2e64 DG |
460 | System call event. Enabling syscalls tracing (kernel tracer), you will |
461 | not be able to disable them with disable-event. This is a known | |
462 | limitation. You can disable the entire channel to do the trick. | |
9bd578f5 | 463 | |
919e300c | 464 | \-\-filter 'expression' |
6b8f2e64 | 465 | Set a filter on a newly enabled event. Filter expression on event |
ee8ccafa MD |
466 | fields and context. Event recording depends on evaluation. Only |
467 | specify on first activation of a given event within a session. | |
468 | Filter only allowed when enabling events within a session before | |
469 | tracing is started. If the filter fails to link with the event | |
470 | within the traced domain, the event will be discarded. | |
471 | Currently, filter is only implemented for the user-space tracer. | |
6b8f2e64 DG |
472 | |
473 | Expression examples: | |
474 | ||
475 | 'intfield > 500 && intfield < 503' | |
476 | '(stringfield == "test" || intfield != 10) && intfield > 33' | |
477 | 'doublefield > 1.1 && intfield < 5.3' | |
478 | ||
479 | Wildcards are allowed at the end of strings: | |
480 | 'seqfield1 == "te*"' | |
481 | In string literals, the escape character is a '\\'. Use '\\*' for | |
ee8ccafa MD |
482 | the '*' character, and '\\\\' for the '\\' character. Wildcard |
483 | match any sequence of characters, including an empty sub-string | |
484 | (match 0 or more characters). | |
485 | ||
486 | Context information can be used for filtering. The examples | |
487 | below show usage of context filtering on process name (with a | |
488 | wildcard), process ID range, and unique thread ID for filtering. | |
489 | The process and thread ID of running applications can be found | |
490 | under columns "PID" and "LWP" of the "ps -eLf" command. | |
491 | ||
492 | '$ctx.procname == "demo*"' | |
493 | '$ctx.vpid >= 4433 && $ctx.vpid < 4455' | |
494 | '$ctx.vtid == 1234' | |
6991b181 DG |
495 | .fi |
496 | ||
c9e32613 | 497 | .IP "\fBdisable-channel\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]" |
6991b181 DG |
498 | .nf |
499 | Disable tracing channel | |
500 | ||
501 | Disabling a channel makes all event(s) in that channel to stop tracing. You can | |
502 | enable it back by calling \fBlttng enable-channel NAME\fP again. | |
503 | ||
c9e32613 | 504 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 DG |
505 | file. |
506 | .fi | |
507 | ||
508 | .B OPTIONS: | |
509 | ||
6b8f2e64 DG |
510 | .nf |
511 | \-h, \-\-help | |
512 | Show summary of possible options and commands. | |
513 | \-\-list-options | |
514 | Simple listing of options | |
515 | \-s, \-\-session NAME | |
6991b181 | 516 | Apply on session name |
c9e32613 | 517 | \-k, \-\-kernel |
6991b181 | 518 | Apply for the kernel tracer |
c9e32613 | 519 | \-u, \-\-userspace |
6991b181 DG |
520 | Apply for the user-space tracer |
521 | .fi | |
522 | ||
c9e32613 | 523 | .IP "\fBdisable-event\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]" |
6991b181 DG |
524 | .nf |
525 | Disable tracing event | |
526 | ||
527 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event | |
528 | NAME\fP again. | |
529 | ||
c9e32613 | 530 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 DG |
531 | file. |
532 | .fi | |
533 | ||
534 | .B OPTIONS: | |
535 | ||
536 | .nf | |
c9e32613 | 537 | \-h, \-\-help |
6991b181 | 538 | Show summary of possible options and commands. |
c9e32613 | 539 | \-\-list-options |
6991b181 | 540 | Simple listing of options |
391b9c72 | 541 | \-s, \-\-session NAME |
6991b181 | 542 | Apply on session name |
c5650942 DG |
543 | \-a, \-\-all-events |
544 | Disable all events. This does NOT disable "*" but rather | |
545 | every known events of the session. | |
c9e32613 | 546 | \-k, \-\-kernel |
6991b181 | 547 | Apply for the kernel tracer |
c9e32613 | 548 | \-u, \-\-userspace |
6991b181 DG |
549 | Apply for the user-space tracer |
550 | .fi | |
551 | ||
c9e32613 | 552 | .IP "\fBlist\fP [\-k|\-u] [SESSION [SESSION_OPTIONS]]" |
6991b181 | 553 | .nf |
c9e32613 | 554 | List tracing session information. |
6991b181 DG |
555 | |
556 | With no arguments, it will list available tracing session(s). | |
557 | ||
fa072eae YB |
558 | With the session name, it will display the details of the session including |
559 | the trace file path, the associated channels and their state (activated | |
d829b38c | 560 | and deactivated), the activated events and more. |
fa072eae | 561 | |
c9e32613 | 562 | With \-k alone, it will list all available kernel events (except the system |
6991b181 | 563 | calls events). |
c9e32613 DG |
564 | With \-u alone, it will list all available user-space events from registered |
565 | applications. Here is an example of 'lttng list \-u': | |
6991b181 DG |
566 | |
567 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello | |
568 | ust_tests_hello:tptest_sighandler (type: tracepoint) | |
569 | ust_tests_hello:tptest (type: tracepoint) | |
570 | ||
571 | You can now enable any event listed by using the name : | |
572 | \fBust_tests_hello:tptest\fP. | |
573 | .fi | |
574 | ||
575 | .B OPTIONS: | |
576 | ||
577 | .nf | |
c9e32613 | 578 | \-h, \-\-help |
6991b181 | 579 | Show summary of possible options and commands. |
c9e32613 | 580 | \-\-list-options |
6991b181 | 581 | Simple listing of options |
c9e32613 | 582 | \-k, \-\-kernel |
d829b38c | 583 | Select kernel domain |
c9e32613 | 584 | \-u, \-\-userspace |
6991b181 DG |
585 | Select user-space domain. |
586 | ||
6b8f2e64 DG |
587 | .B SESSION OPTIONS: |
588 | ||
c9e32613 | 589 | \-c, \-\-channel NAME |
6991b181 | 590 | List details of a channel |
c9e32613 | 591 | \-d, \-\-domain |
6991b181 DG |
592 | List available domain(s) |
593 | .fi | |
594 | ||
595 | .IP "\fBset-session\fP NAME" | |
596 | .nf | |
597 | Set current session name | |
598 | ||
599 | Will change the session name in the .lttngrc file. | |
600 | .fi | |
601 | ||
602 | .B OPTIONS: | |
603 | ||
604 | .nf | |
c9e32613 | 605 | \-h, \-\-help |
6991b181 | 606 | Show summary of possible options and commands. |
c9e32613 | 607 | \-\-list-options |
6991b181 DG |
608 | Simple listing of options |
609 | .fi | |
610 | ||
611 | .IP | |
612 | ||
b872baea DG |
613 | .IP "\fBsnapshot\fP ACTION" |
614 | .nf | |
615 | Snapshot command for LTTng session. | |
616 | .fi | |
617 | ||
618 | .B OPTIONS: | |
619 | ||
620 | .nf | |
621 | \-h, \-\-help | |
622 | Show summary of possible options and commands. | |
623 | \-\-list-options | |
624 | Simple listing of options | |
625 | .fi | |
626 | ||
627 | .B ACTION: | |
628 | ||
629 | .nf | |
630 | \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL> | |
631 | ||
632 | Setup and add an snapshot output for a session. Output are the destination | |
633 | where the snapshot will be sent. Only one output is permitted. To change it, | |
634 | you'll need to delete it and add back the new one. | |
635 | ||
636 | \fBdel-output\fP ID | NAME [-s <NAME>] | |
637 | ||
638 | Delete an output for a session using the ID. You can either specify the | |
639 | output's ID that can be found with list-output or the name. | |
640 | ||
641 | \fBlist-output\fP [-s <NAME>] | |
642 | ||
643 | List the output of a session. Attributes of the output are printed. | |
644 | ||
645 | \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>] | |
646 | ||
647 | Snapshot a session's buffer(s) for all domains. If an URL is specified, it is | |
648 | used instead of a previously added output. Specifying only a name or/and a max | |
649 | size will override the current output values. For instance, you can record a | |
650 | snapshot with a custom maximum size or with a different name. | |
651 | ||
652 | $ lttng add-output -n mysnapshot file:///data/snapshot | |
653 | [...] | |
654 | $ lttng snapshot record -n new_name_snapshot | |
655 | ||
656 | The above will create a snapshot in /data/snapshot/new_name_snapshot* directory | |
657 | rather then in mysnapshot*/ | |
658 | .fi | |
659 | ||
660 | .B LONG OPTIONS | |
661 | ||
662 | .nf | |
3ae6f666 DG |
663 | \-s, \-\-session NAME |
664 | Apply to session name. | |
665 | \-n, \-\-name NAME | |
666 | Name of the snapshot's output. | |
667 | \-m, \-\-max-size SIZE | |
668 | Maximum size in bytes of the snapshot. The maxium size does not | |
669 | include the metadata file. | |
670 | \-C, \-\-ctrl-url URL | |
671 | Set control path URL. (Must use -D also) | |
672 | \-D, \-\-data-url URL | |
673 | Set data path URL. (Must use -C also) | |
b872baea DG |
674 | .fi |
675 | ||
676 | .IP | |
677 | ||
6b8f2e64 | 678 | .IP "\fBstart\fP [NAME] [OPTIONS]" |
6991b181 DG |
679 | .nf |
680 | Start tracing | |
681 | ||
682 | It will start tracing for all tracers for a specific tracing session. | |
683 | ||
684 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
685 | .fi | |
686 | ||
687 | .B OPTIONS: | |
688 | ||
689 | .nf | |
c9e32613 | 690 | \-h, \-\-help |
6991b181 | 691 | Show summary of possible options and commands. |
c9e32613 | 692 | \-\-list-options |
6991b181 DG |
693 | Simple listing of options |
694 | .fi | |
695 | ||
696 | .IP | |
697 | ||
6b8f2e64 | 698 | .IP "\fBstop\fP [NAME] [OPTIONS]" |
6991b181 DG |
699 | .nf |
700 | Stop tracing | |
701 | ||
391b9c72 DG |
702 | It will stop tracing for all tracers for a specific tracing session. Before |
703 | returning, the command checks for data availability meaning that it will wait | |
704 | until the trace is readable for the session. Use \-\-no-wait to avoid this | |
705 | behavior. | |
6991b181 DG |
706 | |
707 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
708 | .fi | |
709 | ||
710 | .B OPTIONS: | |
711 | ||
712 | .nf | |
c9e32613 | 713 | \-h, \-\-help |
6991b181 | 714 | Show summary of possible options and commands. |
c9e32613 | 715 | \-\-list-options |
6991b181 | 716 | Simple listing of options |
391b9c72 DG |
717 | \-\-no-wait |
718 | Don't wait for data availability. | |
6991b181 DG |
719 | .fi |
720 | ||
721 | .IP | |
722 | ||
723 | .IP "\fBversion\fP" | |
724 | .nf | |
725 | Show version information | |
726 | .fi | |
727 | ||
728 | .B OPTIONS: | |
729 | ||
730 | .nf | |
c9e32613 | 731 | \-h, \-\-help |
6991b181 | 732 | Show summary of possible options and commands. |
c9e32613 | 733 | \-\-list-options |
6991b181 DG |
734 | Simple listing of options |
735 | .fi | |
736 | ||
737 | .IP | |
738 | ||
739 | .IP "\fBview\fP [SESSION_NAME] [OPTIONS]" | |
740 | .nf | |
741 | View traces of a tracing session | |
742 | ||
743 | By default, the babeltrace viewer will be used for text viewing. | |
744 | ||
fa072eae YB |
745 | If SESSION_NAME is omitted, the session name is taken from the .lttngrc file. |
746 | ||
6991b181 DG |
747 | .fi |
748 | ||
749 | .B OPTIONS: | |
750 | ||
751 | .nf | |
c9e32613 | 752 | \-h, \-\-help |
6991b181 | 753 | Show this help |
c9e32613 | 754 | \-\-list-options |
6991b181 | 755 | Simple listing of options |
c9e32613 | 756 | \-t, \-\-trace-path PATH |
6991b181 | 757 | Trace directory path for the viewer |
c9e32613 | 758 | \-e, \-\-viewer CMD |
6991b181 DG |
759 | Specify viewer and/or options to use |
760 | This will completely override the default viewers so | |
761 | please make sure to specify the full command. The trace | |
762 | directory path of the session will be appended at the end | |
763 | to the arguments | |
764 | .fi | |
765 | ||
c206d957 | 766 | .SH "EXIT VALUES" |
6b8f2e64 DG |
767 | On success 0 is returned and a positive value on error. Value of 1 means a command |
768 | error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that | |
769 | something went wrong during the command. | |
c206d957 | 770 | |
6b8f2e64 DG |
771 | Any other value above 10, please refer to |
772 | .BR <lttng/lttng-error.h> | |
773 | for a detailed list or use lttng_strerror() to get a human readable string of | |
774 | the error code. | |
c206d957 | 775 | |
c206d957 | 776 | .PP |
6991b181 DG |
777 | .SH "ENVIRONMENT VARIABLES" |
778 | ||
779 | .PP | |
780 | Note that all command line options override environment variables. | |
781 | .PP | |
782 | ||
783 | .PP | |
05833633 | 784 | .IP "LTTNG_SESSIOND_PATH" |
c9e32613 DG |
785 | Allows one to specify the full session daemon binary path to lttng command line |
786 | tool. You can also use \-\-sessiond-path option having the same effect. | |
6991b181 | 787 | .SH "SEE ALSO" |
6b8f2e64 DG |
788 | .BR babeltrace(1), |
789 | .BR lttng-ust(3), | |
790 | .BR lttng-sessiond(8), | |
791 | .BR lttng-relayd(8), | |
792 | .BR lttng-health-check(3) | |
6991b181 DG |
793 | .SH "BUGS" |
794 | ||
6991b181 | 795 | If you encounter any issues or usability problem, please report it on our |
6b8f2e64 DG |
796 | mailing list <lttng-dev@lists.lttng.org> to help improve this project or |
797 | at https://bugs.lttng.org which is a bugtracker. | |
6991b181 DG |
798 | .SH "CREDITS" |
799 | ||
800 | .PP | |
c9e32613 | 801 | lttng is distributed under the GNU General Public License version 2. See the file |
6991b181 DG |
802 | COPYING for details. |
803 | .PP | |
804 | A Web site is available at http://lttng.org for more information on the LTTng | |
805 | project. | |
806 | .PP | |
807 | You can also find our git tree at http://git.lttng.org. | |
808 | .PP | |
809 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. | |
810 | .PP | |
811 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. | |
812 | .PP | |
813 | .SH "THANKS" | |
814 | ||
815 | .PP | |
816 | Thanks to Yannick Brosseau without whom this project would never have been so | |
817 | lean and mean! Also thanks to the Ericsson teams working on tracing which | |
fa072eae | 818 | helped us greatly with detailed bug reports and unusual test cases. |
6991b181 DG |
819 | |
820 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA | |
821 | maintainer) and Jon Bernard for our Debian packages. | |
822 | ||
823 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de | |
824 | Montreal for the LTTng journey. | |
c9e32613 | 825 | .PP |
6991b181 DG |
826 | .SH "AUTHORS" |
827 | ||
828 | .PP | |
829 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and | |
830 | David Goulet. More people have since contributed to it. It is currently | |
831 | maintained by David Goulet <dgoulet@efficios.com>. | |
832 | .PP |