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b107a0b1 | 1 | .TH "LTTNG" "1" "July 18th, 2013" "" "" |
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 | |
6991b181 | 9 | lttng [OPTIONS] <COMMAND> |
6991b181 DG |
10 | .SH "DESCRIPTION" |
11 | ||
12 | .PP | |
13 | The LTTng project aims at providing highly efficient tracing tools for Linux. | |
14 | It's tracers help tracking down performance issues and debugging problems | |
15 | involving multiple concurrent processes and threads. Tracing across multiple | |
16 | systems is also possible. | |
17 | ||
fa072eae | 18 | The \fBlttng\fP command line tool from the lttng-tools package is used to control |
6991b181 DG |
19 | both kernel and user-space tracing. Every interactions with the tracer should |
20 | be done by this tool or by the liblttng-ctl provided with the lttng-tools | |
21 | package. | |
22 | ||
23 | LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry, | |
50a3b92a | 24 | which allows you to interact with multiple tracers (kernel and user-space) |
6991b181 DG |
25 | inside the same container, a tracing session. Traces can be gathered from the |
26 | kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading | |
27 | those traces is done using the babeltrace(1) text viewer. | |
28 | ||
50a3b92a DG |
29 | We introduce the notion of \fBtracing domains\fP which is essentially a type of |
30 | tracer (kernel or user space for now). In the future, we could see a third | |
31 | tracer being for instance an hypervisor. For some commands, you'll need to | |
32 | specify on which domain the command applies (-u or -k). For instance, enabling | |
33 | a kernel event, you must specify the kernel domain to the command so we know | |
34 | for which tracer this event is for. | |
35 | ||
6991b181 DG |
36 | In order to trace the kernel, the session daemon needs to be running as root. |
37 | LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is | |
38 | in that group can interact with the root session daemon and thus trace the | |
39 | kernel. Session daemons can co-exist meaning that you can have a session daemon | |
fa072eae YB |
40 | running as Alice that can be used to trace her applications along side with a |
41 | root daemon or even a Bob daemon. We highly recommend to start the session | |
6991b181 DG |
42 | daemon at boot time for stable and long term tracing. |
43 | ||
44 | Every user-space applications instrumented with lttng-ust(3), will | |
45 | automatically register to the session daemon. This feature gives you the | |
46 | ability to list available traceable applications and tracepoints on a per user | |
47 | basis. (See \fBlist\fP command). | |
48 | .SH "OPTIONS" | |
49 | ||
50 | .PP | |
51 | This program follow the usual GNU command line syntax with long options starting with | |
52 | two dashes. Below is a summary of the available options. | |
53 | .PP | |
54 | ||
55 | .TP | |
c9e32613 | 56 | .BR "\-h, \-\-help" |
6991b181 DG |
57 | Show summary of possible options and commands. |
58 | .TP | |
c9e32613 | 59 | .BR "\-v, \-\-verbose" |
6991b181 | 60 | Increase verbosity. |
d829b38c | 61 | Three levels of verbosity are available which are triggered by putting additional v to |
fa072eae | 62 | the option (\-vv or \-vvv) |
6991b181 | 63 | .TP |
c9e32613 | 64 | .BR "\-q, \-\-quiet" |
6991b181 DG |
65 | Suppress all messages (even errors). |
66 | .TP | |
c9e32613 | 67 | .BR "\-g, \-\-group NAME" |
6991b181 DG |
68 | Set unix tracing group name. (default: tracing) |
69 | .TP | |
c9e32613 | 70 | .BR "\-n, \-\-no-sessiond" |
6991b181 DG |
71 | Don't automatically spawn a session daemon. |
72 | .TP | |
391b9c72 | 73 | .BR "\-\-sessiond\-path PATH" |
6991b181 DG |
74 | Set session daemon full binary path. |
75 | .TP | |
c9e32613 | 76 | .BR "\-\-list\-options" |
6991b181 DG |
77 | Simple listing of lttng options. |
78 | .TP | |
c9e32613 | 79 | .BR "\-\-list\-commands" |
6991b181 DG |
80 | Simple listing of lttng commands. |
81 | .SH "COMMANDS" | |
82 | ||
812a5eb7 | 83 | .PP |
ee2758e5 | 84 | \fBadd-context\fP [OPTIONS] |
812a5eb7 | 85 | .RS |
6991b181 DG |
86 | Add context to event(s) and/or channel(s). |
87 | ||
391b9c72 DG |
88 | A context is basically extra information appended to a channel. For instance, |
89 | you could ask the tracer to add the PID information for all events in a | |
90 | channel. You can also add performance monitoring unit counters (perf PMU) using | |
91 | the perf kernel API). | |
6991b181 DG |
92 | |
93 | For example, this command will add the context information 'prio' and two perf | |
94 | counters (hardware branch misses and cache misses), to all events in the trace | |
95 | data output: | |
96 | ||
812a5eb7 MD |
97 | .nf |
98 | # lttng add-context \-k \-t prio \-t perf:branch-misses \\ | |
99 | \-t perf:cache-misses | |
100 | .fi | |
6991b181 | 101 | |
c9e32613 | 102 | Please take a look at the help (\-h/\-\-help) for a detailed list of available |
6991b181 DG |
103 | contexts. |
104 | ||
bd337b98 DG |
105 | If no channel is given (\-c), the context is added to all channels that were |
106 | already enabled. If the session has no channel, a default channel is created. | |
107 | Otherwise the context will be added only to the given channel (\-c). | |
6991b181 | 108 | |
c9e32613 | 109 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 110 | file. |
6991b181 DG |
111 | |
112 | .B OPTIONS: | |
113 | ||
812a5eb7 MD |
114 | .TP |
115 | .BR "\-h, \-\-help" | |
116 | Show summary of possible options and commands. | |
117 | .TP | |
118 | .BR "\-s, \-\-session NAME" | |
119 | Apply on session name. | |
120 | .TP | |
121 | .BR "\-c, \-\-channel NAME" | |
122 | Apply on channel name. | |
123 | .TP | |
124 | .BR "\-k, \-\-kernel" | |
125 | Apply for the kernel tracer | |
126 | .TP | |
127 | .BR "\-u, \-\-userspace" | |
128 | Apply for the user-space tracer | |
129 | .TP | |
130 | .BR "\-t, \-\-type TYPE" | |
131 | Context type. You can repeat this option on the command line. Please | |
132 | use "lttng add-context \-h" to list all available types. | |
133 | .RE | |
134 | .PP | |
6991b181 | 135 | |
22019883 MD |
136 | .PP |
137 | \fBcalibrate\fP [OPTIONS] | |
138 | .RS | |
6991b181 DG |
139 | Quantify LTTng overhead |
140 | ||
141 | The LTTng calibrate command can be used to find out the combined average | |
142 | overhead of the LTTng tracer and the instrumentation mechanisms used. This | |
143 | overhead can be calibrated in terms of time or using any of the PMU performance | |
144 | counter available on the system. | |
145 | ||
146 | For now, the only calibration implemented is that of the kernel function | |
147 | instrumentation (kretprobes). | |
148 | ||
149 | * Calibrate kernel function instrumentation | |
150 | ||
151 | Let's use an example to show this calibration. We use an i7 processor with 4 | |
152 | general-purpose PMU registers. This information is available by issuing dmesg, | |
153 | looking for "generic registers". | |
154 | ||
155 | This sequence of commands will gather a trace executing a kretprobe hooked on | |
156 | an empty function, gathering PMU counters LLC (Last Level Cache) misses | |
c9e32613 | 157 | information (see lttng add-context \-\-help to see the list of available PMU |
6991b181 DG |
158 | counters). |
159 | ||
22019883 | 160 | .nf |
6991b181 | 161 | # lttng create calibrate-function |
22019883 MD |
162 | # lttng enable-event calibrate \-\-kernel \\ |
163 | \-\-function lttng_calibrate_kretprobe | |
164 | # lttng add-context \-\-kernel \-t perf:LLC-load-misses \\ | |
165 | \-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 | |
22019883 MD |
172 | # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\ |
173 | | tail \-n 1) | |
174 | .fi | |
6991b181 DG |
175 | |
176 | The output from babeltrace can be saved to a text file and opened in a | |
177 | spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between | |
178 | consecutive "calibrate_entry" and "calibrate_return" events. Note that these | |
179 | counters are per-CPU, so scheduling events would need to be present to account | |
180 | for migration between CPU. Therefore, for calibration purposes, only events | |
181 | staying on the same CPU must be considered. | |
182 | ||
183 | The average result, for the i7, on 10 samples: | |
184 | ||
22019883 | 185 | .nf |
6991b181 DG |
186 | Average Std.Dev. |
187 | perf_LLC_load_misses: 5.0 0.577 | |
188 | perf_LLC_store_misses: 1.6 0.516 | |
189 | perf_LLC_prefetch_misses: 9.0 14.742 | |
22019883 | 190 | .fi |
6991b181 DG |
191 | |
192 | As we can notice, the load and store misses are relatively stable across runs | |
193 | (their standard deviation is relatively low) compared to the prefetch misses. | |
194 | We can conclude from this information that LLC load and store misses can be | |
195 | accounted for quite precisely, but prefetches within a function seems to behave | |
196 | too erratically (not much causality link between the code executed and the CPU | |
197 | prefetch activity) to be accounted for. | |
6991b181 DG |
198 | |
199 | .B OPTIONS: | |
200 | ||
22019883 MD |
201 | .TP |
202 | .BR "\-h, \-\-help" | |
203 | Show summary of possible options and commands. | |
204 | .TP | |
205 | .BR "\-k, \-\-kernel" | |
206 | Apply for the kernel tracer | |
207 | .TP | |
208 | .BR "\-u, \-\-userspace" | |
209 | Apply for the user-space tracer | |
210 | .TP | |
211 | .BR "\-\-function" | |
212 | Dynamic function entry/return probe (default) | |
213 | .RE | |
214 | .PP | |
6991b181 | 215 | |
ee2758e5 MD |
216 | .PP |
217 | .IP \fBcreate\fP [NAME] [OPTIONS] | |
218 | .RS | |
6991b181 DG |
219 | Create tracing session. |
220 | ||
221 | A tracing session contains channel(s) which contains event(s). It is domain | |
222 | agnostic meaning that you can enable channels and events for either the | |
223 | user-space tracer and/or the kernel tracer. It acts like a container | |
224 | aggregating multiple tracing sources. | |
225 | ||
226 | On creation, a \fB.lttngrc\fP file is created in your $HOME directory | |
227 | containing the current session name. If NAME is omitted, a session name is | |
fa072eae | 228 | automatically created having this form: 'auto-yyyymmdd-hhmmss'. |
6991b181 | 229 | |
c9e32613 | 230 | If no \fB\-o, \-\-output\fP is specified, the traces will be written in |
6991b181 | 231 | $HOME/lttng-traces. |
feb0f3e5 AM |
232 | |
233 | The $HOME environment variable can be overridden by defining the environment | |
234 | variable LTTNG_HOME. This is useful when the user running the commands has | |
235 | a non-writeable home directory. | |
6991b181 DG |
236 | |
237 | .B OPTIONS: | |
238 | ||
ee2758e5 MD |
239 | .TP |
240 | .BR "\-h, \-\-help" | |
241 | Show summary of possible options and commands. | |
242 | .TP | |
243 | .BR "\-\-list-options" | |
244 | Simple listing of options | |
245 | .TP | |
246 | .BR "\-o, \-\-output PATH" | |
247 | Specify output path for traces | |
248 | .TP | |
249 | .BR "\-\-no-output" | |
250 | Traces will not be outputed | |
251 | .TP | |
252 | .BR "\-\-snapshot" | |
253 | Set the session in snapshot mode. Created in no-output mode and uses the | |
254 | URL, if one, as the default snapshot output. Every channel will be set | |
255 | in overwrite mode and with mmap output (splice not supported). | |
6b8f2e64 | 256 | |
ee2758e5 MD |
257 | .TP |
258 | .BR "\-U, \-\-set-url=URL" | |
259 | Set URL for the consumer output destination. It is persistent for the | |
260 | session lifetime. Redo the command to change it. This will set both data | |
261 | and control URL for network. | |
262 | .TP | |
263 | .BR "\-C, \-\-ctrl-url=URL" | |
264 | Set control path URL. (Must use -D also) | |
265 | .TP | |
266 | .BR "\-D, \-\-data-url=URL" | |
267 | Set data path URL. (Must use -C also) | |
268 | .PP | |
6b8f2e64 DG |
269 | Using these options, each API call can be controlled individually. For |
270 | instance, \-C does not enable the consumer automatically. You'll need the \-e | |
271 | option for that. | |
272 | ||
785d2d0d DG |
273 | .B URL FORMAT: |
274 | ||
275 | proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] | |
276 | ||
277 | Supported protocols are (proto): | |
ee2758e5 MD |
278 | .TP |
279 | .BR "file://..." | |
280 | Local filesystem full path. | |
785d2d0d | 281 | |
ee2758e5 MD |
282 | .TP |
283 | .BR "net://..." | |
284 | This will use the default network transport layer which is TCP for both | |
285 | control (PORT1) and data port (PORT2). The default ports are | |
286 | respectively 5342 and 5343. Note that net[6]:// is not yet supported. | |
785d2d0d | 287 | |
ee2758e5 MD |
288 | .TP |
289 | .BR "tcp[6]://..." | |
290 | Can only be used with -C and -D together | |
785d2d0d DG |
291 | |
292 | NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732) | |
6b8f2e64 DG |
293 | |
294 | .B EXAMPLES: | |
295 | ||
ee2758e5 | 296 | .nf |
6b8f2e64 | 297 | # lttng create -U net://192.168.1.42 |
ee2758e5 | 298 | .fi |
6b8f2e64 DG |
299 | Uses TCP and default ports for the given destination. |
300 | ||
ee2758e5 | 301 | .nf |
6b8f2e64 | 302 | # lttng create -U net6://[fe80::f66d:4ff:fe53:d220] |
ee2758e5 | 303 | .fi |
6b8f2e64 DG |
304 | Uses TCP, default ports and IPv6. |
305 | ||
ee2758e5 | 306 | .nf |
6b8f2e64 | 307 | # lttng create s1 -U net://myhost.com:3229 |
6991b181 | 308 | .fi |
ee2758e5 MD |
309 | Create session s1 and set its consumer to myhost.com on port 3229 for control. |
310 | .RE | |
311 | .PP | |
6991b181 | 312 | |
f2b14ef1 MD |
313 | .PP |
314 | \fBdestroy\fP [NAME] [OPTIONS] | |
315 | .RS | |
6991b181 DG |
316 | Teardown tracing session |
317 | ||
318 | Free memory on the session daemon and tracer side. It's gone! | |
319 | ||
320 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
321 | |
322 | .B OPTIONS: | |
323 | ||
f2b14ef1 MD |
324 | .TP |
325 | .BR "\-h, \-\-help" | |
326 | Show summary of possible options and commands. | |
327 | .TP | |
328 | .BR "\-a, \-\-all" | |
329 | Destroy all sessions | |
330 | .TP | |
331 | .BR "\-\-list-options" | |
332 | Simple listing of options | |
333 | .RE | |
334 | .PP | |
6991b181 | 335 | |
05be3802 MD |
336 | .PP |
337 | \fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
338 | .RS | |
6991b181 DG |
339 | Enable tracing channel |
340 | ||
004f3466 DG |
341 | To enable an event, you must enable both the event and the channel that |
342 | contains it. | |
b883c01b | 343 | |
c9e32613 | 344 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 345 | file. |
7972aab2 | 346 | |
05be3802 MD |
347 | Exactly one of \-k or -u must be specified. |
348 | ||
7972aab2 | 349 | It is important to note that if a certain type of buffers is used, the session |
bd337b98 | 350 | will be set with that type and all other subsequent channel needs to have the |
7972aab2 | 351 | same type. |
bd337b98 | 352 | |
d2f11c4a DG |
353 | Note that once the session has been started and enabled on the tracer side, |
354 | it's not possible anymore to enable a new channel for that session. | |
6991b181 DG |
355 | |
356 | .B OPTIONS: | |
357 | ||
05be3802 MD |
358 | .TP |
359 | .BR "\-h, \-\-help" | |
360 | Show this help | |
361 | .TP | |
362 | .BR "\-\-list-options" | |
363 | Simple listing of options | |
364 | .TP | |
365 | .BR "\-s, \-\-session NAME" | |
366 | Apply on session name | |
367 | .TP | |
368 | .BR "\-k, \-\-kernel" | |
369 | Apply to the kernel tracer | |
370 | .TP | |
371 | .BR "\-u, \-\-userspace" | |
372 | Apply to the user-space tracer | |
373 | .TP | |
374 | .BR "\-\-discard" | |
375 | Discard event when subbuffers are full (default) | |
376 | .TP | |
377 | .BR "\-\-overwrite" | |
378 | Flight recorder mode : overwrites events when subbuffers are full | |
379 | .TP | |
380 | .BR "\-\-subbuf-size SIZE" | |
381 | Subbuffer size in bytes {+k,+M,+G}. | |
382 | (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096) | |
383 | Rounded up to the next power of 2. | |
384 | ||
385 | The minimum subbuffer size, for each tracer, is the max value between | |
386 | the default above and the system page size. You can issue this command | |
387 | to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP | |
388 | .TP | |
389 | .BR "\-\-num-subbuf NUM" | |
390 | Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4, | |
391 | metadata: 2) Rounded up to the next power of 2. | |
392 | .TP | |
393 | .BR "\-\-switch-timer USEC" | |
394 | Switch subbuffer timer interval in µsec. | |
395 | (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0) | |
396 | .TP | |
397 | .BR "\-\-read-timer USEC" | |
398 | Read timer interval in µsec. | |
399 | (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0) | |
400 | .TP | |
401 | .BR "\-\-output TYPE" | |
402 | Channel output type. Possible values: mmap, splice | |
403 | (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap) | |
404 | .TP | |
405 | .BR "\-\-buffers-uid" | |
406 | Use per UID buffer (\-u only). Buffers are shared between applications | |
407 | that have the same UID. | |
408 | .TP | |
409 | .BR "\-\-buffers-pid" | |
410 | Use per PID buffer (\-u only). Each application has its own buffers. | |
411 | .TP | |
412 | .BR "\-\-buffers-global" | |
413 | Use shared buffer for the whole system (\-k only) | |
414 | .TP | |
415 | .BR "\-C, \-\-tracefile-size SIZE" | |
416 | Maximum size of each tracefile within a stream (in bytes). | |
417 | 0 means unlimited. (default: 0) | |
418 | .TP | |
419 | .BR "\-W, \-\-tracefile-count COUNT" | |
420 | Used in conjunction with \-C option, this will limit the number of files | |
421 | created to the specified count. 0 means unlimited. (default: 0) | |
1624d5b7 JD |
422 | |
423 | .B EXAMPLES: | |
424 | ||
05be3802 MD |
425 | .nf |
426 | $ lttng enable-channel -k -C 4096 -W 32 chan1 | |
427 | .fi | |
cea28771 DG |
428 | For each stream, the maximum size of each trace file will be 4096 bytes, and |
429 | there will be a maximum of 32 different files. The file count is appended after | |
1624d5b7 JD |
430 | the stream number as seen in the following example. The last trace file is |
431 | smaller than 4096 since it was not completely filled. | |
432 | ||
05be3802 | 433 | .nf |
1624d5b7 JD |
434 | ~/lttng-traces/[...]/chan1_0_0 (4096) |
435 | ~/lttng-traces/[...]/chan1_0_1 (4096) | |
436 | ~/lttng-traces/[...]/chan1_0_2 (3245) | |
437 | ~/lttng-traces/[...]/chan1_1_0 (4096) | |
438 | ... | |
05be3802 | 439 | .fi |
1624d5b7 | 440 | |
05be3802 MD |
441 | .nf |
442 | $ lttng enable-channel -k -C 4096 | |
443 | .fi | |
1624d5b7 JD |
444 | This will create trace files of 4096 bytes and will create new ones as long as |
445 | there is data available. | |
05be3802 MD |
446 | .RE |
447 | .PP | |
6991b181 | 448 | |
6a240cd9 MD |
449 | .PP |
450 | \fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS] | |
451 | .RS | |
6991b181 DG |
452 | Enable tracing event |
453 | ||
c9e32613 | 454 | A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is |
6991b181 | 455 | omitted, a default channel named '\fBchannel0\fP' is created and the event is |
c9e32613 | 456 | added to it. For the user-space tracer, using \fB\-a, \-\-all\fP is the same as |
6991b181 DG |
457 | using the wildcard "*". |
458 | ||
c9e32613 | 459 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 460 | file. |
6991b181 DG |
461 | |
462 | .B OPTIONS: | |
463 | ||
6a240cd9 MD |
464 | .TP |
465 | .BR "\-h, \-\-help" | |
466 | Show summary of possible options and commands. | |
467 | .TP | |
468 | .BR "\-\-list-options" | |
469 | Simple listing of options | |
470 | .TP | |
471 | .BR "\-s, \-\-session NAME" | |
472 | Apply on session name | |
473 | .TP | |
474 | .BR "\-c, \-\-channel NAME" | |
475 | Apply on channel name | |
476 | .TP | |
477 | .BR "\-a, \-\-all" | |
478 | Enable all tracepoints and syscalls. This actually enable a single | |
479 | wildcard event "*". | |
480 | .TP | |
481 | .BR "\-k, \-\-kernel" | |
482 | Apply for the kernel tracer | |
483 | .TP | |
484 | .BR "\-u, \-\-userspace" | |
485 | Apply for the user-space tracer | |
486 | .TP | |
487 | .BR "\-\-tracepoint" | |
488 | Tracepoint event (default). Userspace tracer supports wildcards at end | |
489 | of string. Don't forget to quote to deal with bash expansion. | |
490 | e.g.: | |
6991b181 | 491 | .nf |
6991b181 DG |
492 | "*" |
493 | "app_component:na*" | |
6991b181 | 494 | .fi |
6a240cd9 MD |
495 | .TP |
496 | .BR "\-\-loglevel NAME" | |
497 | Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h). | |
498 | .TP | |
499 | .BR "\-\-loglevel-only NAME" | |
500 | Tracepoint loglevel (only this loglevel). | |
501 | The loglevel or loglevel-only options should be combined with a | |
502 | tracepoint name or tracepoint wildcard. | |
503 | .TP | |
504 | .BR "\-\-probe (addr | symbol | symbol+offset)" | |
505 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) | |
506 | or hexadecimal (0xNNN...) | |
507 | .TP | |
508 | .BR "\-\-function (addr | symbol | symbol+offset)" | |
509 | Dynamic function entry/return probe. Addr and offset can be octal | |
510 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) | |
511 | .TP | |
512 | .BR "\-\-syscall" | |
513 | System call event. Enabling syscalls tracing (kernel tracer), you will | |
514 | not be able to disable them with disable-event. This is a known | |
515 | limitation. You can disable the entire channel to do the trick. | |
516 | .TP | |
517 | .BR "\-\-filter 'expression'" | |
518 | Set a filter on a newly enabled event. Filter expression on event | |
519 | fields and context. Event recording depends on evaluation. Only | |
520 | specify on first activation of a given event within a session. | |
521 | Filter only allowed when enabling events within a session before | |
522 | tracing is started. If the filter fails to link with the event | |
523 | within the traced domain, the event will be discarded. | |
524 | Currently, filter is only implemented for the user-space tracer. | |
525 | ||
526 | Expression examples: | |
527 | ||
528 | .nf | |
529 | 'intfield > 500 && intfield < 503' | |
530 | '(strfield == "test" || intfield != 10) && intfield > 33' | |
531 | 'doublefield > 1.1 && intfield < 5.3' | |
532 | .fi | |
533 | ||
534 | Wildcards are allowed at the end of strings: | |
535 | 'seqfield1 == "te*"' | |
536 | In string literals, the escape character is a '\\'. Use '\\*' for | |
537 | the '*' character, and '\\\\' for the '\\' character. Wildcard | |
538 | match any sequence of characters, including an empty sub-string | |
539 | (match 0 or more characters). | |
540 | ||
541 | Context information can be used for filtering. The examples below show | |
542 | usage of context filtering on process name (with a wildcard), process ID | |
543 | range, and unique thread ID for filtering. The process and thread ID of | |
544 | running applications can be found under columns "PID" and "LWP" of the | |
545 | "ps -eLf" command. | |
546 | ||
547 | .nf | |
548 | '$ctx.procname == "demo*"' | |
549 | '$ctx.vpid >= 4433 && $ctx.vpid < 4455' | |
550 | '$ctx.vtid == 1234' | |
551 | .fi | |
552 | ||
553 | .RE | |
554 | .PP | |
6991b181 | 555 | |
272c6a17 MD |
556 | .PP |
557 | \fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
558 | .RS | |
6991b181 DG |
559 | Disable tracing channel |
560 | ||
561 | Disabling a channel makes all event(s) in that channel to stop tracing. You can | |
562 | enable it back by calling \fBlttng enable-channel NAME\fP again. | |
563 | ||
c9e32613 | 564 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 565 | file. |
6991b181 DG |
566 | |
567 | .B OPTIONS: | |
568 | ||
272c6a17 MD |
569 | .TP |
570 | .BR "\-h, \-\-help" | |
571 | Show summary of possible options and commands. | |
572 | .TP | |
573 | .BR "\-\-list-options" | |
574 | Simple listing of options | |
575 | .TP | |
576 | .BR "\-s, \-\-session NAME" | |
577 | Apply on session name | |
578 | .TP | |
579 | .BR "\-k, \-\-kernel" | |
580 | Apply for the kernel tracer | |
581 | .TP | |
582 | .BR "\-u, \-\-userspace" | |
583 | Apply for the user-space tracer | |
584 | .RE | |
585 | .PP | |
6991b181 | 586 | |
c138a39b MD |
587 | .PP |
588 | \fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
589 | .RS | |
6991b181 DG |
590 | Disable tracing event |
591 | ||
592 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event | |
593 | NAME\fP again. | |
594 | ||
c9e32613 | 595 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 596 | file. |
6991b181 DG |
597 | |
598 | .B OPTIONS: | |
599 | ||
c138a39b MD |
600 | .TP |
601 | .BR "\-h, \-\-help" | |
602 | Show summary of possible options and commands. | |
603 | .TP | |
604 | .BR "\-\-list-options" | |
605 | Simple listing of options | |
606 | .TP | |
607 | .BR "\-s, \-\-session NAME" | |
608 | Apply on session name | |
609 | .TP | |
610 | .BR "\-a, \-\-all-events" | |
611 | Disable all events. This does NOT disable "*" but rather every known | |
612 | events of the session. | |
613 | .TP | |
614 | .BR "\-k, \-\-kernel" | |
615 | Apply for the kernel tracer | |
616 | .TP | |
617 | .BR "\-u, \-\-userspace" | |
618 | Apply for the user-space tracer | |
619 | .RE | |
620 | .PP | |
6991b181 | 621 | |
747361fe MD |
622 | .PP |
623 | \fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]] | |
624 | .RS | |
c9e32613 | 625 | List tracing session information. |
6991b181 DG |
626 | |
627 | With no arguments, it will list available tracing session(s). | |
628 | ||
fa072eae YB |
629 | With the session name, it will display the details of the session including |
630 | the trace file path, the associated channels and their state (activated | |
d829b38c | 631 | and deactivated), the activated events and more. |
fa072eae | 632 | |
c9e32613 | 633 | With \-k alone, it will list all available kernel events (except the system |
6991b181 | 634 | calls events). |
c9e32613 DG |
635 | With \-u alone, it will list all available user-space events from registered |
636 | applications. Here is an example of 'lttng list \-u': | |
6991b181 | 637 | |
747361fe | 638 | .nf |
6991b181 DG |
639 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello |
640 | ust_tests_hello:tptest_sighandler (type: tracepoint) | |
641 | ust_tests_hello:tptest (type: tracepoint) | |
747361fe | 642 | .fi |
6991b181 DG |
643 | |
644 | You can now enable any event listed by using the name : | |
645 | \fBust_tests_hello:tptest\fP. | |
6991b181 DG |
646 | |
647 | .B OPTIONS: | |
648 | ||
747361fe MD |
649 | .TP |
650 | .BR "\-h, \-\-help" | |
651 | Show summary of possible options and commands. | |
652 | .TP | |
653 | .BR "\-\-list-options" | |
654 | Simple listing of options | |
655 | .TP | |
656 | .BR "\-k, \-\-kernel" | |
657 | Select kernel domain | |
658 | .TP | |
659 | .BR "\-u, \-\-userspace" | |
660 | Select user-space domain. | |
6991b181 | 661 | |
747361fe | 662 | .PP |
6b8f2e64 DG |
663 | .B SESSION OPTIONS: |
664 | ||
747361fe MD |
665 | .TP |
666 | .BR "\-c, \-\-channel NAME" | |
667 | List details of a channel | |
668 | .TP | |
669 | .BR "\-d, \-\-domain" | |
670 | List available domain(s) | |
671 | .RE | |
672 | .PP | |
6991b181 | 673 | |
7c96a096 MD |
674 | .PP |
675 | \fBset-session\fP NAME [OPTIONS] | |
676 | .RS | |
6991b181 DG |
677 | Set current session name |
678 | ||
679 | Will change the session name in the .lttngrc file. | |
6991b181 DG |
680 | |
681 | .B OPTIONS: | |
682 | ||
7c96a096 MD |
683 | .TP |
684 | .BR "\-h, \-\-help" | |
685 | Show summary of possible options and commands. | |
686 | .TP | |
687 | .BR "\-\-list-options" | |
688 | Simple listing of options | |
689 | .RE | |
690 | .PP | |
6991b181 | 691 | |
8df3bfe9 MD |
692 | .PP |
693 | \fBsnapshot\fP [OPTIONS] ACTION | |
694 | .RS | |
b872baea | 695 | Snapshot command for LTTng session. |
b872baea DG |
696 | |
697 | .B OPTIONS: | |
698 | ||
8df3bfe9 MD |
699 | .TP |
700 | .BR "\-h, \-\-help" | |
701 | Show summary of possible options and commands. | |
702 | .TP | |
703 | .BR "\-\-list-options" | |
704 | Simple listing of options | |
b872baea | 705 | |
8df3bfe9 | 706 | .PP |
b872baea DG |
707 | .B ACTION: |
708 | ||
8df3bfe9 | 709 | .TP |
b872baea DG |
710 | \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL> |
711 | ||
712 | Setup and add an snapshot output for a session. Output are the destination | |
713 | where the snapshot will be sent. Only one output is permitted. To change it, | |
714 | you'll need to delete it and add back the new one. | |
715 | ||
8df3bfe9 | 716 | .TP |
b872baea DG |
717 | \fBdel-output\fP ID | NAME [-s <NAME>] |
718 | ||
719 | Delete an output for a session using the ID. You can either specify the | |
720 | output's ID that can be found with list-output or the name. | |
721 | ||
8df3bfe9 | 722 | .TP |
b872baea DG |
723 | \fBlist-output\fP [-s <NAME>] |
724 | ||
725 | List the output of a session. Attributes of the output are printed. | |
726 | ||
8df3bfe9 | 727 | .TP |
b872baea DG |
728 | \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>] |
729 | ||
730 | Snapshot a session's buffer(s) for all domains. If an URL is specified, it is | |
731 | used instead of a previously added output. Specifying only a name or/and a max | |
732 | size will override the current output values. For instance, you can record a | |
733 | snapshot with a custom maximum size or with a different name. | |
734 | ||
8df3bfe9 | 735 | .nf |
b872baea DG |
736 | $ lttng add-output -n mysnapshot file:///data/snapshot |
737 | [...] | |
738 | $ lttng snapshot record -n new_name_snapshot | |
8df3bfe9 | 739 | .fi |
b872baea DG |
740 | |
741 | The above will create a snapshot in /data/snapshot/new_name_snapshot* directory | |
742 | rather then in mysnapshot*/ | |
b872baea | 743 | |
8df3bfe9 MD |
744 | .PP |
745 | .B DETAILED ACTION OPTIONS | |
b872baea | 746 | |
8df3bfe9 MD |
747 | .TP |
748 | .BR "\-s, \-\-session NAME" | |
749 | Apply to session name. | |
750 | .TP | |
751 | .BR "\-n, \-\-name NAME" | |
752 | Name of the snapshot's output. | |
753 | .TP | |
754 | .BR "\-m, \-\-max-size SIZE" | |
755 | Maximum size in bytes of the snapshot. The maxium size does not include | |
756 | the metadata file. | |
757 | .TP | |
758 | .BR "\-C, \-\-ctrl-url URL" | |
759 | Set control path URL. (Must use -D also) | |
760 | .TP | |
761 | .BR "\-D, \-\-data-url URL" | |
762 | Set data path URL. (Must use -C also) | |
763 | .RE | |
764 | .PP | |
b872baea | 765 | |
afb8ca1b MD |
766 | .PP |
767 | \fBstart\fP [NAME] [OPTIONS] | |
768 | .RS | |
6991b181 DG |
769 | Start tracing |
770 | ||
771 | It will start tracing for all tracers for a specific tracing session. | |
6991b181 | 772 | If NAME is omitted, the session name is taken from the .lttngrc file. |
6991b181 DG |
773 | |
774 | .B OPTIONS: | |
775 | ||
afb8ca1b MD |
776 | .TP |
777 | .BR "\-h, \-\-help" | |
778 | Show summary of possible options and commands. | |
779 | .TP | |
780 | .BR "\-\-list-options" | |
781 | Simple listing of options | |
782 | .RE | |
783 | .PP | |
6991b181 | 784 | |
6c09bfdb MD |
785 | .PP |
786 | \fBstop\fP [NAME] [OPTIONS] | |
787 | .RS | |
6991b181 DG |
788 | Stop tracing |
789 | ||
391b9c72 DG |
790 | It will stop tracing for all tracers for a specific tracing session. Before |
791 | returning, the command checks for data availability meaning that it will wait | |
792 | until the trace is readable for the session. Use \-\-no-wait to avoid this | |
793 | behavior. | |
6991b181 DG |
794 | |
795 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
796 | |
797 | .B OPTIONS: | |
798 | ||
6c09bfdb MD |
799 | .TP |
800 | .BR "\-h, \-\-help" | |
801 | Show summary of possible options and commands. | |
802 | .TP | |
803 | .BR "\-\-list-options" | |
804 | Simple listing of options | |
805 | .TP "\-\-no-wait" | |
806 | Don't wait for data availability. | |
807 | .RE | |
808 | .PP | |
6991b181 | 809 | |
5975c30a MD |
810 | .PP |
811 | \fBversion\fP | |
812 | .RS | |
6991b181 | 813 | Show version information |
6991b181 DG |
814 | |
815 | .B OPTIONS: | |
816 | ||
5975c30a MD |
817 | .TP |
818 | .BR "\-h, \-\-help" | |
819 | Show summary of possible options and commands. | |
820 | .TP | |
821 | .BR "\-\-list-options" | |
822 | Simple listing of options | |
823 | .RE | |
824 | .PP | |
6991b181 | 825 | |
5b4c1410 MD |
826 | .PP |
827 | \fBview\fP [SESSION_NAME] [OPTIONS] | |
828 | .RS | |
829 | View traces of a tracing session. By default, the babeltrace viewer | |
830 | will be used for text viewing. If SESSION_NAME is omitted, the session | |
831 | name is taken from the .lttngrc file. | |
6991b181 DG |
832 | |
833 | .B OPTIONS: | |
834 | ||
5b4c1410 MD |
835 | .TP |
836 | .BR "\-h, \-\-help" | |
837 | Show this help | |
838 | .TP | |
839 | .BR "\-\-list-options" | |
840 | Simple listing of options | |
841 | .TP | |
842 | .BR "\-t, \-\-trace-path PATH" | |
843 | Trace directory path for the viewer | |
844 | .TP | |
845 | .BR "\-e, \-\-viewer CMD" | |
846 | Specify viewer and/or options to use This will completely override the | |
847 | default viewers so please make sure to specify the full command. The | |
848 | trace directory path of the session will be appended at the end to the | |
849 | arguments | |
850 | .RE | |
851 | .PP | |
6991b181 | 852 | |
c206d957 | 853 | .SH "EXIT VALUES" |
b107a0b1 | 854 | .PP |
6b8f2e64 DG |
855 | On success 0 is returned and a positive value on error. Value of 1 means a command |
856 | error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that | |
857 | something went wrong during the command. | |
c206d957 | 858 | |
6b8f2e64 | 859 | Any other value above 10, please refer to |
b107a0b1 | 860 | .BR "<lttng/lttng-error.h>" |
6b8f2e64 DG |
861 | for a detailed list or use lttng_strerror() to get a human readable string of |
862 | the error code. | |
c206d957 | 863 | .PP |
b107a0b1 | 864 | |
6991b181 DG |
865 | .SH "ENVIRONMENT VARIABLES" |
866 | ||
867 | .PP | |
868 | Note that all command line options override environment variables. | |
869 | .PP | |
870 | ||
871 | .PP | |
05833633 | 872 | .IP "LTTNG_SESSIOND_PATH" |
c9e32613 DG |
873 | Allows one to specify the full session daemon binary path to lttng command line |
874 | tool. You can also use \-\-sessiond-path option having the same effect. | |
b107a0b1 MD |
875 | .PP |
876 | ||
6991b181 | 877 | .SH "SEE ALSO" |
6b8f2e64 DG |
878 | .BR babeltrace(1), |
879 | .BR lttng-ust(3), | |
880 | .BR lttng-sessiond(8), | |
881 | .BR lttng-relayd(8), | |
882 | .BR lttng-health-check(3) | |
b107a0b1 | 883 | |
6991b181 DG |
884 | .SH "BUGS" |
885 | ||
b107a0b1 | 886 | .PP |
6991b181 | 887 | If you encounter any issues or usability problem, please report it on our |
6b8f2e64 DG |
888 | mailing list <lttng-dev@lists.lttng.org> to help improve this project or |
889 | at https://bugs.lttng.org which is a bugtracker. | |
b107a0b1 MD |
890 | .PP |
891 | ||
6991b181 DG |
892 | .SH "CREDITS" |
893 | ||
894 | .PP | |
c9e32613 | 895 | lttng is distributed under the GNU General Public License version 2. See the file |
6991b181 DG |
896 | COPYING for details. |
897 | .PP | |
898 | A Web site is available at http://lttng.org for more information on the LTTng | |
899 | project. | |
900 | .PP | |
901 | You can also find our git tree at http://git.lttng.org. | |
902 | .PP | |
903 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. | |
904 | .PP | |
905 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. | |
906 | .PP | |
907 | .SH "THANKS" | |
908 | ||
909 | .PP | |
910 | Thanks to Yannick Brosseau without whom this project would never have been so | |
911 | lean and mean! Also thanks to the Ericsson teams working on tracing which | |
fa072eae | 912 | helped us greatly with detailed bug reports and unusual test cases. |
6991b181 DG |
913 | |
914 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA | |
915 | maintainer) and Jon Bernard for our Debian packages. | |
916 | ||
917 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de | |
918 | Montreal for the LTTng journey. | |
c9e32613 | 919 | .PP |
6991b181 DG |
920 | .SH "AUTHORS" |
921 | ||
922 | .PP | |
923 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and | |
924 | David Goulet. More people have since contributed to it. It is currently | |
925 | maintained by David Goulet <dgoulet@efficios.com>. | |
926 | .PP |