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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. | |
31ea4846 | 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 | 216 | .PP |
feb3ca56 | 217 | \fBcreate\fP [NAME] [OPTIONS] |
ee2758e5 | 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" | |
a2d6893b | 250 | Traces will not be outputted |
ee2758e5 MD |
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 |
85076754 MD |
456 | added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default |
457 | channel already exists within the session, an error is returned. For the | |
458 | user-space tracer, using \fB\-a, \-\-all\fP is the same as using the | |
459 | wildcard "*". | |
6991b181 | 460 | |
c9e32613 | 461 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 462 | file. |
6991b181 DG |
463 | |
464 | .B OPTIONS: | |
465 | ||
6a240cd9 MD |
466 | .TP |
467 | .BR "\-h, \-\-help" | |
468 | Show summary of possible options and commands. | |
469 | .TP | |
470 | .BR "\-\-list-options" | |
471 | Simple listing of options | |
472 | .TP | |
473 | .BR "\-s, \-\-session NAME" | |
474 | Apply on session name | |
475 | .TP | |
476 | .BR "\-c, \-\-channel NAME" | |
477 | Apply on channel name | |
478 | .TP | |
479 | .BR "\-a, \-\-all" | |
480 | Enable all tracepoints and syscalls. This actually enable a single | |
481 | wildcard event "*". | |
482 | .TP | |
483 | .BR "\-k, \-\-kernel" | |
484 | Apply for the kernel tracer | |
485 | .TP | |
486 | .BR "\-u, \-\-userspace" | |
487 | Apply for the user-space tracer | |
488 | .TP | |
489 | .BR "\-\-tracepoint" | |
490 | Tracepoint event (default). Userspace tracer supports wildcards at end | |
491 | of string. Don't forget to quote to deal with bash expansion. | |
492 | e.g.: | |
6991b181 | 493 | .nf |
6991b181 DG |
494 | "*" |
495 | "app_component:na*" | |
6991b181 | 496 | .fi |
6a240cd9 MD |
497 | .TP |
498 | .BR "\-\-loglevel NAME" | |
499 | Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h). | |
500 | .TP | |
501 | .BR "\-\-loglevel-only NAME" | |
502 | Tracepoint loglevel (only this loglevel). | |
503 | The loglevel or loglevel-only options should be combined with a | |
504 | tracepoint name or tracepoint wildcard. | |
505 | .TP | |
506 | .BR "\-\-probe (addr | symbol | symbol+offset)" | |
507 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) | |
508 | or hexadecimal (0xNNN...) | |
509 | .TP | |
510 | .BR "\-\-function (addr | symbol | symbol+offset)" | |
511 | Dynamic function entry/return probe. Addr and offset can be octal | |
512 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) | |
513 | .TP | |
514 | .BR "\-\-syscall" | |
515 | System call event. Enabling syscalls tracing (kernel tracer), you will | |
516 | not be able to disable them with disable-event. This is a known | |
517 | limitation. You can disable the entire channel to do the trick. | |
518 | .TP | |
519 | .BR "\-\-filter 'expression'" | |
520 | Set a filter on a newly enabled event. Filter expression on event | |
521 | fields and context. Event recording depends on evaluation. Only | |
522 | specify on first activation of a given event within a session. | |
523 | Filter only allowed when enabling events within a session before | |
524 | tracing is started. If the filter fails to link with the event | |
525 | within the traced domain, the event will be discarded. | |
526 | Currently, filter is only implemented for the user-space tracer. | |
527 | ||
528 | Expression examples: | |
529 | ||
530 | .nf | |
531 | 'intfield > 500 && intfield < 503' | |
532 | '(strfield == "test" || intfield != 10) && intfield > 33' | |
533 | 'doublefield > 1.1 && intfield < 5.3' | |
534 | .fi | |
535 | ||
536 | Wildcards are allowed at the end of strings: | |
537 | 'seqfield1 == "te*"' | |
538 | In string literals, the escape character is a '\\'. Use '\\*' for | |
539 | the '*' character, and '\\\\' for the '\\' character. Wildcard | |
540 | match any sequence of characters, including an empty sub-string | |
541 | (match 0 or more characters). | |
542 | ||
543 | Context information can be used for filtering. The examples below show | |
544 | usage of context filtering on process name (with a wildcard), process ID | |
545 | range, and unique thread ID for filtering. The process and thread ID of | |
546 | running applications can be found under columns "PID" and "LWP" of the | |
547 | "ps -eLf" command. | |
548 | ||
549 | .nf | |
550 | '$ctx.procname == "demo*"' | |
551 | '$ctx.vpid >= 4433 && $ctx.vpid < 4455' | |
552 | '$ctx.vtid == 1234' | |
553 | .fi | |
554 | ||
555 | .RE | |
556 | .PP | |
6991b181 | 557 | |
272c6a17 MD |
558 | .PP |
559 | \fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
560 | .RS | |
6991b181 DG |
561 | Disable tracing channel |
562 | ||
563 | Disabling a channel makes all event(s) in that channel to stop tracing. You can | |
564 | enable it back by calling \fBlttng enable-channel NAME\fP again. | |
565 | ||
c9e32613 | 566 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 567 | file. |
6991b181 DG |
568 | |
569 | .B OPTIONS: | |
570 | ||
272c6a17 MD |
571 | .TP |
572 | .BR "\-h, \-\-help" | |
573 | Show summary of possible options and commands. | |
574 | .TP | |
575 | .BR "\-\-list-options" | |
576 | Simple listing of options | |
577 | .TP | |
578 | .BR "\-s, \-\-session NAME" | |
579 | Apply on session name | |
580 | .TP | |
581 | .BR "\-k, \-\-kernel" | |
582 | Apply for the kernel tracer | |
583 | .TP | |
584 | .BR "\-u, \-\-userspace" | |
585 | Apply for the user-space tracer | |
586 | .RE | |
587 | .PP | |
6991b181 | 588 | |
c138a39b MD |
589 | .PP |
590 | \fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
591 | .RS | |
6991b181 DG |
592 | Disable tracing event |
593 | ||
594 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event | |
595 | NAME\fP again. | |
596 | ||
c9e32613 | 597 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 598 | file. |
6991b181 | 599 | |
85076754 MD |
600 | If \fB\-c, \-\-channel\fP is omitted, the default channel name is used. |
601 | If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already | |
602 | exists within the session, an error is returned. | |
603 | ||
6991b181 DG |
604 | .B OPTIONS: |
605 | ||
c138a39b MD |
606 | .TP |
607 | .BR "\-h, \-\-help" | |
608 | Show summary of possible options and commands. | |
609 | .TP | |
610 | .BR "\-\-list-options" | |
611 | Simple listing of options | |
612 | .TP | |
613 | .BR "\-s, \-\-session NAME" | |
614 | Apply on session name | |
615 | .TP | |
85076754 MD |
616 | .BR "\-c, \-\-channel NAME" |
617 | Apply on channel name | |
618 | .TP | |
c138a39b MD |
619 | .BR "\-a, \-\-all-events" |
620 | Disable all events. This does NOT disable "*" but rather every known | |
621 | events of the session. | |
622 | .TP | |
623 | .BR "\-k, \-\-kernel" | |
624 | Apply for the kernel tracer | |
625 | .TP | |
626 | .BR "\-u, \-\-userspace" | |
627 | Apply for the user-space tracer | |
628 | .RE | |
629 | .PP | |
6991b181 | 630 | |
747361fe MD |
631 | .PP |
632 | \fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]] | |
633 | .RS | |
c9e32613 | 634 | List tracing session information. |
6991b181 DG |
635 | |
636 | With no arguments, it will list available tracing session(s). | |
637 | ||
fa072eae YB |
638 | With the session name, it will display the details of the session including |
639 | the trace file path, the associated channels and their state (activated | |
d829b38c | 640 | and deactivated), the activated events and more. |
fa072eae | 641 | |
c9e32613 | 642 | With \-k alone, it will list all available kernel events (except the system |
6991b181 | 643 | calls events). |
c9e32613 DG |
644 | With \-u alone, it will list all available user-space events from registered |
645 | applications. Here is an example of 'lttng list \-u': | |
6991b181 | 646 | |
747361fe | 647 | .nf |
6991b181 DG |
648 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello |
649 | ust_tests_hello:tptest_sighandler (type: tracepoint) | |
650 | ust_tests_hello:tptest (type: tracepoint) | |
747361fe | 651 | .fi |
6991b181 DG |
652 | |
653 | You can now enable any event listed by using the name : | |
654 | \fBust_tests_hello:tptest\fP. | |
6991b181 DG |
655 | |
656 | .B OPTIONS: | |
657 | ||
747361fe MD |
658 | .TP |
659 | .BR "\-h, \-\-help" | |
660 | Show summary of possible options and commands. | |
661 | .TP | |
662 | .BR "\-\-list-options" | |
663 | Simple listing of options | |
664 | .TP | |
665 | .BR "\-k, \-\-kernel" | |
666 | Select kernel domain | |
667 | .TP | |
668 | .BR "\-u, \-\-userspace" | |
669 | Select user-space domain. | |
6991b181 | 670 | |
747361fe | 671 | .PP |
6b8f2e64 DG |
672 | .B SESSION OPTIONS: |
673 | ||
747361fe MD |
674 | .TP |
675 | .BR "\-c, \-\-channel NAME" | |
676 | List details of a channel | |
677 | .TP | |
678 | .BR "\-d, \-\-domain" | |
679 | List available domain(s) | |
680 | .RE | |
681 | .PP | |
6991b181 | 682 | |
7c96a096 MD |
683 | .PP |
684 | \fBset-session\fP NAME [OPTIONS] | |
685 | .RS | |
6991b181 DG |
686 | Set current session name |
687 | ||
688 | Will change the session name in the .lttngrc file. | |
6991b181 DG |
689 | |
690 | .B OPTIONS: | |
691 | ||
7c96a096 MD |
692 | .TP |
693 | .BR "\-h, \-\-help" | |
694 | Show summary of possible options and commands. | |
695 | .TP | |
696 | .BR "\-\-list-options" | |
697 | Simple listing of options | |
698 | .RE | |
699 | .PP | |
6991b181 | 700 | |
8df3bfe9 MD |
701 | .PP |
702 | \fBsnapshot\fP [OPTIONS] ACTION | |
703 | .RS | |
b872baea | 704 | Snapshot command for LTTng session. |
b872baea DG |
705 | |
706 | .B OPTIONS: | |
707 | ||
8df3bfe9 MD |
708 | .TP |
709 | .BR "\-h, \-\-help" | |
710 | Show summary of possible options and commands. | |
711 | .TP | |
712 | .BR "\-\-list-options" | |
713 | Simple listing of options | |
b872baea | 714 | |
8df3bfe9 | 715 | .PP |
b872baea DG |
716 | .B ACTION: |
717 | ||
8df3bfe9 | 718 | .TP |
b872baea DG |
719 | \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL> |
720 | ||
721 | Setup and add an snapshot output for a session. Output are the destination | |
722 | where the snapshot will be sent. Only one output is permitted. To change it, | |
723 | you'll need to delete it and add back the new one. | |
724 | ||
8df3bfe9 | 725 | .TP |
b872baea DG |
726 | \fBdel-output\fP ID | NAME [-s <NAME>] |
727 | ||
728 | Delete an output for a session using the ID. You can either specify the | |
729 | output's ID that can be found with list-output or the name. | |
730 | ||
8df3bfe9 | 731 | .TP |
b872baea DG |
732 | \fBlist-output\fP [-s <NAME>] |
733 | ||
734 | List the output of a session. Attributes of the output are printed. | |
735 | ||
8df3bfe9 | 736 | .TP |
b872baea DG |
737 | \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>] |
738 | ||
739 | Snapshot a session's buffer(s) for all domains. If an URL is specified, it is | |
740 | used instead of a previously added output. Specifying only a name or/and a max | |
741 | size will override the current output values. For instance, you can record a | |
742 | snapshot with a custom maximum size or with a different name. | |
743 | ||
8df3bfe9 | 744 | .nf |
b872baea DG |
745 | $ lttng add-output -n mysnapshot file:///data/snapshot |
746 | [...] | |
747 | $ lttng snapshot record -n new_name_snapshot | |
8df3bfe9 | 748 | .fi |
b872baea DG |
749 | |
750 | The above will create a snapshot in /data/snapshot/new_name_snapshot* directory | |
751 | rather then in mysnapshot*/ | |
b872baea | 752 | |
8df3bfe9 MD |
753 | .PP |
754 | .B DETAILED ACTION OPTIONS | |
b872baea | 755 | |
8df3bfe9 MD |
756 | .TP |
757 | .BR "\-s, \-\-session NAME" | |
758 | Apply to session name. | |
759 | .TP | |
760 | .BR "\-n, \-\-name NAME" | |
761 | Name of the snapshot's output. | |
762 | .TP | |
763 | .BR "\-m, \-\-max-size SIZE" | |
764 | Maximum size in bytes of the snapshot. The maxium size does not include | |
765 | the metadata file. | |
766 | .TP | |
767 | .BR "\-C, \-\-ctrl-url URL" | |
768 | Set control path URL. (Must use -D also) | |
769 | .TP | |
770 | .BR "\-D, \-\-data-url URL" | |
771 | Set data path URL. (Must use -C also) | |
772 | .RE | |
773 | .PP | |
b872baea | 774 | |
afb8ca1b MD |
775 | .PP |
776 | \fBstart\fP [NAME] [OPTIONS] | |
777 | .RS | |
6991b181 DG |
778 | Start tracing |
779 | ||
780 | It will start tracing for all tracers for a specific tracing session. | |
6991b181 | 781 | If NAME is omitted, the session name is taken from the .lttngrc file. |
6991b181 DG |
782 | |
783 | .B OPTIONS: | |
784 | ||
afb8ca1b MD |
785 | .TP |
786 | .BR "\-h, \-\-help" | |
787 | Show summary of possible options and commands. | |
788 | .TP | |
789 | .BR "\-\-list-options" | |
790 | Simple listing of options | |
791 | .RE | |
792 | .PP | |
6991b181 | 793 | |
6c09bfdb MD |
794 | .PP |
795 | \fBstop\fP [NAME] [OPTIONS] | |
796 | .RS | |
6991b181 DG |
797 | Stop tracing |
798 | ||
391b9c72 DG |
799 | It will stop tracing for all tracers for a specific tracing session. Before |
800 | returning, the command checks for data availability meaning that it will wait | |
801 | until the trace is readable for the session. Use \-\-no-wait to avoid this | |
802 | behavior. | |
6991b181 DG |
803 | |
804 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
805 | |
806 | .B OPTIONS: | |
807 | ||
6c09bfdb MD |
808 | .TP |
809 | .BR "\-h, \-\-help" | |
810 | Show summary of possible options and commands. | |
811 | .TP | |
812 | .BR "\-\-list-options" | |
813 | Simple listing of options | |
814 | .TP "\-\-no-wait" | |
815 | Don't wait for data availability. | |
816 | .RE | |
817 | .PP | |
6991b181 | 818 | |
5975c30a MD |
819 | .PP |
820 | \fBversion\fP | |
821 | .RS | |
6991b181 | 822 | Show version information |
6991b181 DG |
823 | |
824 | .B OPTIONS: | |
825 | ||
5975c30a MD |
826 | .TP |
827 | .BR "\-h, \-\-help" | |
828 | Show summary of possible options and commands. | |
829 | .TP | |
830 | .BR "\-\-list-options" | |
831 | Simple listing of options | |
832 | .RE | |
833 | .PP | |
6991b181 | 834 | |
5b4c1410 MD |
835 | .PP |
836 | \fBview\fP [SESSION_NAME] [OPTIONS] | |
837 | .RS | |
838 | View traces of a tracing session. By default, the babeltrace viewer | |
839 | will be used for text viewing. If SESSION_NAME is omitted, the session | |
840 | name is taken from the .lttngrc file. | |
6991b181 DG |
841 | |
842 | .B OPTIONS: | |
843 | ||
5b4c1410 MD |
844 | .TP |
845 | .BR "\-h, \-\-help" | |
846 | Show this help | |
847 | .TP | |
848 | .BR "\-\-list-options" | |
849 | Simple listing of options | |
850 | .TP | |
851 | .BR "\-t, \-\-trace-path PATH" | |
852 | Trace directory path for the viewer | |
853 | .TP | |
854 | .BR "\-e, \-\-viewer CMD" | |
855 | Specify viewer and/or options to use This will completely override the | |
856 | default viewers so please make sure to specify the full command. The | |
857 | trace directory path of the session will be appended at the end to the | |
858 | arguments | |
859 | .RE | |
860 | .PP | |
6991b181 | 861 | |
c206d957 | 862 | .SH "EXIT VALUES" |
b107a0b1 | 863 | .PP |
6b8f2e64 DG |
864 | On success 0 is returned and a positive value on error. Value of 1 means a command |
865 | error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that | |
866 | something went wrong during the command. | |
c206d957 | 867 | |
6b8f2e64 | 868 | Any other value above 10, please refer to |
b107a0b1 | 869 | .BR "<lttng/lttng-error.h>" |
6b8f2e64 DG |
870 | for a detailed list or use lttng_strerror() to get a human readable string of |
871 | the error code. | |
c206d957 | 872 | .PP |
b107a0b1 | 873 | |
6991b181 DG |
874 | .SH "ENVIRONMENT VARIABLES" |
875 | ||
876 | .PP | |
877 | Note that all command line options override environment variables. | |
878 | .PP | |
879 | ||
880 | .PP | |
05833633 | 881 | .IP "LTTNG_SESSIOND_PATH" |
c9e32613 DG |
882 | Allows one to specify the full session daemon binary path to lttng command line |
883 | tool. You can also use \-\-sessiond-path option having the same effect. | |
b107a0b1 MD |
884 | .PP |
885 | ||
6991b181 | 886 | .SH "SEE ALSO" |
6b8f2e64 DG |
887 | .BR babeltrace(1), |
888 | .BR lttng-ust(3), | |
889 | .BR lttng-sessiond(8), | |
890 | .BR lttng-relayd(8), | |
891 | .BR lttng-health-check(3) | |
b107a0b1 | 892 | |
6991b181 DG |
893 | .SH "BUGS" |
894 | ||
b107a0b1 | 895 | .PP |
6991b181 | 896 | If you encounter any issues or usability problem, please report it on our |
6b8f2e64 DG |
897 | mailing list <lttng-dev@lists.lttng.org> to help improve this project or |
898 | at https://bugs.lttng.org which is a bugtracker. | |
b107a0b1 MD |
899 | .PP |
900 | ||
6991b181 DG |
901 | .SH "CREDITS" |
902 | ||
903 | .PP | |
c9e32613 | 904 | lttng is distributed under the GNU General Public License version 2. See the file |
6991b181 DG |
905 | COPYING for details. |
906 | .PP | |
907 | A Web site is available at http://lttng.org for more information on the LTTng | |
908 | project. | |
909 | .PP | |
910 | You can also find our git tree at http://git.lttng.org. | |
911 | .PP | |
912 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. | |
913 | .PP | |
914 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. | |
915 | .PP | |
916 | .SH "THANKS" | |
917 | ||
918 | .PP | |
919 | Thanks to Yannick Brosseau without whom this project would never have been so | |
920 | lean and mean! Also thanks to the Ericsson teams working on tracing which | |
fa072eae | 921 | helped us greatly with detailed bug reports and unusual test cases. |
6991b181 DG |
922 | |
923 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA | |
924 | maintainer) and Jon Bernard for our Debian packages. | |
925 | ||
926 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de | |
927 | Montreal for the LTTng journey. | |
c9e32613 | 928 | .PP |
6991b181 DG |
929 | .SH "AUTHORS" |
930 | ||
931 | .PP | |
932 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and | |
933 | David Goulet. More people have since contributed to it. It is currently | |
934 | maintained by David Goulet <dgoulet@efficios.com>. | |
935 | .PP |