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acf47627 | 1 | .TH "LTTNG" "1" "February 05th, 2014" "" "" |
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. | |
e256d661 | 14 | Its tracers help track down performance issues and debug problems |
6991b181 DG |
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 |
e256d661 JG |
19 | both kernel and user-space tracing. Every interaction with the tracer should |
20 | be done by this tool or by the liblttng-ctl library provided by the lttng-tools | |
6991b181 DG |
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 | 29 | We introduce the notion of \fBtracing domains\fP which is essentially a type of |
acf47627 DG |
30 | tracer (kernel, user space or JUL for now). In the future, we could see more |
31 | tracer like for instance an hypervisor. For some commands, you'll need to | |
32 | specify on which domain the command operates (\-u, \-k or \-j). For instance, | |
33 | the kernel domain must be specified when enabling a kernel event. | |
50a3b92a | 34 | |
6991b181 DG |
35 | In order to trace the kernel, the session daemon needs to be running as root. |
36 | LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is | |
37 | in that group can interact with the root session daemon and thus trace the | |
e256d661 | 38 | kernel. Session daemons can co-exist, meaning that you can have a session daemon |
fa072eae | 39 | running as Alice that can be used to trace her applications along side with a |
e256d661 | 40 | root daemon or even a Bob daemon. We highly recommend starting the session |
6991b181 DG |
41 | daemon at boot time for stable and long term tracing. |
42 | ||
274d6c5d DG |
43 | Each user-space application instrumented with lttng-ust(3) will automatically |
44 | register with the root session daemon and its user session daemon. This allows | |
45 | each daemon to list the available traceable applications and tracepoints at any | |
46 | given moment (See the \fBlist\fP command). | |
6991b181 DG |
47 | .SH "OPTIONS" |
48 | ||
49 | .PP | |
50 | This program follow the usual GNU command line syntax with long options starting with | |
51 | two dashes. Below is a summary of the available options. | |
52 | .PP | |
53 | ||
54 | .TP | |
c9e32613 | 55 | .BR "\-h, \-\-help" |
6991b181 DG |
56 | Show summary of possible options and commands. |
57 | .TP | |
c9e32613 | 58 | .BR "\-v, \-\-verbose" |
6991b181 | 59 | Increase verbosity. |
d829b38c | 60 | Three levels of verbosity are available which are triggered by putting additional v to |
fa072eae | 61 | the option (\-vv or \-vvv) |
6991b181 | 62 | .TP |
c9e32613 | 63 | .BR "\-q, \-\-quiet" |
6991b181 DG |
64 | Suppress all messages (even errors). |
65 | .TP | |
c9e32613 | 66 | .BR "\-g, \-\-group NAME" |
6991b181 DG |
67 | Set unix tracing group name. (default: tracing) |
68 | .TP | |
c9e32613 | 69 | .BR "\-n, \-\-no-sessiond" |
6991b181 DG |
70 | Don't automatically spawn a session daemon. |
71 | .TP | |
391b9c72 | 72 | .BR "\-\-sessiond\-path PATH" |
6991b181 DG |
73 | Set session daemon full binary path. |
74 | .TP | |
c9e32613 | 75 | .BR "\-\-list\-options" |
6991b181 DG |
76 | Simple listing of lttng options. |
77 | .TP | |
c9e32613 | 78 | .BR "\-\-list\-commands" |
6991b181 DG |
79 | Simple listing of lttng commands. |
80 | .SH "COMMANDS" | |
81 | ||
812a5eb7 | 82 | .PP |
ee2758e5 | 83 | \fBadd-context\fP [OPTIONS] |
812a5eb7 | 84 | .RS |
6991b181 DG |
85 | Add context to event(s) and/or channel(s). |
86 | ||
391b9c72 DG |
87 | A context is basically extra information appended to a channel. For instance, |
88 | you could ask the tracer to add the PID information for all events in a | |
89 | channel. You can also add performance monitoring unit counters (perf PMU) using | |
aa3514e9 | 90 | the perf kernel API. |
6991b181 | 91 | |
aa3514e9 MD |
92 | For example, this command will add the context information 'prio' and two per-CPU |
93 | perf counters (hardware branch misses and cache misses), to all events in the trace | |
6991b181 DG |
94 | data output: |
95 | ||
812a5eb7 | 96 | .nf |
aa3514e9 MD |
97 | # lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\ |
98 | \-t perf:cpu:cache-misses | |
812a5eb7 | 99 | .fi |
6991b181 | 100 | |
c9e32613 | 101 | Please take a look at the help (\-h/\-\-help) for a detailed list of available |
6991b181 DG |
102 | contexts. |
103 | ||
aa3514e9 MD |
104 | Perf counters are available as per-CPU ("perf:cpu:...") and per-thread |
105 | ("perf:thread:...") counters. Currently, per-CPU counters can only be | |
106 | used with the kernel tracing domain, and per-thread counters can only be | |
107 | used with the UST tracing domain. | |
108 | ||
bd337b98 DG |
109 | If no channel is given (\-c), the context is added to all channels that were |
110 | already enabled. If the session has no channel, a default channel is created. | |
31ea4846 | 111 | Otherwise the context will be added only to the given channel (\-c). |
6991b181 | 112 | |
c9e32613 | 113 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 114 | file. |
6991b181 DG |
115 | |
116 | .B OPTIONS: | |
117 | ||
812a5eb7 MD |
118 | .TP |
119 | .BR "\-h, \-\-help" | |
120 | Show summary of possible options and commands. | |
121 | .TP | |
122 | .BR "\-s, \-\-session NAME" | |
123 | Apply on session name. | |
124 | .TP | |
125 | .BR "\-c, \-\-channel NAME" | |
126 | Apply on channel name. | |
127 | .TP | |
128 | .BR "\-k, \-\-kernel" | |
129 | Apply for the kernel tracer | |
130 | .TP | |
131 | .BR "\-u, \-\-userspace" | |
132 | Apply for the user-space tracer | |
133 | .TP | |
134 | .BR "\-t, \-\-type TYPE" | |
135 | Context type. You can repeat this option on the command line. Please | |
136 | use "lttng add-context \-h" to list all available types. | |
137 | .RE | |
138 | .PP | |
6991b181 | 139 | |
22019883 MD |
140 | .PP |
141 | \fBcalibrate\fP [OPTIONS] | |
142 | .RS | |
6991b181 DG |
143 | Quantify LTTng overhead |
144 | ||
145 | The LTTng calibrate command can be used to find out the combined average | |
146 | overhead of the LTTng tracer and the instrumentation mechanisms used. This | |
147 | overhead can be calibrated in terms of time or using any of the PMU performance | |
148 | counter available on the system. | |
149 | ||
150 | For now, the only calibration implemented is that of the kernel function | |
151 | instrumentation (kretprobes). | |
152 | ||
153 | * Calibrate kernel function instrumentation | |
154 | ||
155 | Let's use an example to show this calibration. We use an i7 processor with 4 | |
156 | general-purpose PMU registers. This information is available by issuing dmesg, | |
157 | looking for "generic registers". | |
158 | ||
159 | This sequence of commands will gather a trace executing a kretprobe hooked on | |
160 | an empty function, gathering PMU counters LLC (Last Level Cache) misses | |
c9e32613 | 161 | information (see lttng add-context \-\-help to see the list of available PMU |
6991b181 DG |
162 | counters). |
163 | ||
22019883 | 164 | .nf |
6991b181 | 165 | # lttng create calibrate-function |
22019883 MD |
166 | # lttng enable-event calibrate \-\-kernel \\ |
167 | \-\-function lttng_calibrate_kretprobe | |
aa3514e9 MD |
168 | # lttng add-context \-\-kernel \-t perf:cpu:LLC-load-misses \\ |
169 | \-t perf:cpu:LLC-store-misses \\ | |
170 | \-t perf:cpu:LLC-prefetch-misses | |
6991b181 DG |
171 | # lttng start |
172 | # for a in $(seq 1 10); do \\ | |
c9e32613 | 173 | lttng calibrate \-\-kernel \-\-function; |
6991b181 DG |
174 | done |
175 | # lttng destroy | |
22019883 MD |
176 | # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* \\ |
177 | | tail \-n 1) | |
178 | .fi | |
6991b181 DG |
179 | |
180 | The output from babeltrace can be saved to a text file and opened in a | |
181 | spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between | |
182 | consecutive "calibrate_entry" and "calibrate_return" events. Note that these | |
183 | counters are per-CPU, so scheduling events would need to be present to account | |
184 | for migration between CPU. Therefore, for calibration purposes, only events | |
185 | staying on the same CPU must be considered. | |
186 | ||
187 | The average result, for the i7, on 10 samples: | |
188 | ||
22019883 | 189 | .nf |
6991b181 DG |
190 | Average Std.Dev. |
191 | perf_LLC_load_misses: 5.0 0.577 | |
192 | perf_LLC_store_misses: 1.6 0.516 | |
193 | perf_LLC_prefetch_misses: 9.0 14.742 | |
22019883 | 194 | .fi |
6991b181 DG |
195 | |
196 | As we can notice, the load and store misses are relatively stable across runs | |
197 | (their standard deviation is relatively low) compared to the prefetch misses. | |
198 | We can conclude from this information that LLC load and store misses can be | |
199 | accounted for quite precisely, but prefetches within a function seems to behave | |
200 | too erratically (not much causality link between the code executed and the CPU | |
201 | prefetch activity) to be accounted for. | |
6991b181 DG |
202 | |
203 | .B OPTIONS: | |
204 | ||
22019883 MD |
205 | .TP |
206 | .BR "\-h, \-\-help" | |
207 | Show summary of possible options and commands. | |
208 | .TP | |
209 | .BR "\-k, \-\-kernel" | |
210 | Apply for the kernel tracer | |
211 | .TP | |
212 | .BR "\-u, \-\-userspace" | |
213 | Apply for the user-space tracer | |
214 | .TP | |
215 | .BR "\-\-function" | |
216 | Dynamic function entry/return probe (default) | |
217 | .RE | |
218 | .PP | |
6991b181 | 219 | |
ee2758e5 | 220 | .PP |
feb3ca56 | 221 | \fBcreate\fP [NAME] [OPTIONS] |
ee2758e5 | 222 | .RS |
6991b181 DG |
223 | Create tracing session. |
224 | ||
225 | A tracing session contains channel(s) which contains event(s). It is domain | |
e256d661 | 226 | agnostic, meaning that channels and events can be enabled for the |
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227 | user-space tracer and/or the kernel tracer. It acts like a container |
228 | aggregating multiple tracing sources. | |
229 | ||
230 | On creation, a \fB.lttngrc\fP file is created in your $HOME directory | |
231 | containing the current session name. If NAME is omitted, a session name is | |
fa072eae | 232 | automatically created having this form: 'auto-yyyymmdd-hhmmss'. |
6991b181 | 233 | |
c9e32613 | 234 | If no \fB\-o, \-\-output\fP is specified, the traces will be written in |
6991b181 | 235 | $HOME/lttng-traces. |
feb0f3e5 AM |
236 | |
237 | The $HOME environment variable can be overridden by defining the environment | |
238 | variable LTTNG_HOME. This is useful when the user running the commands has | |
239 | a non-writeable home directory. | |
6991b181 | 240 | |
1c1c3634 DG |
241 | The session name MUST NOT contain the character '/'. |
242 | ||
6991b181 DG |
243 | .B OPTIONS: |
244 | ||
ee2758e5 MD |
245 | .TP |
246 | .BR "\-h, \-\-help" | |
247 | Show summary of possible options and commands. | |
248 | .TP | |
249 | .BR "\-\-list-options" | |
250 | Simple listing of options | |
251 | .TP | |
252 | .BR "\-o, \-\-output PATH" | |
253 | Specify output path for traces | |
254 | .TP | |
255 | .BR "\-\-no-output" | |
e256d661 | 256 | Traces will not be output |
ee2758e5 MD |
257 | .TP |
258 | .BR "\-\-snapshot" | |
259 | Set the session in snapshot mode. Created in no-output mode and uses the | |
e256d661 | 260 | URL, if one is specified, as the default snapshot output. Every channel will be set |
ee2758e5 | 261 | in overwrite mode and with mmap output (splice not supported). |
0794f51b | 262 | .TP |
d73c5802 | 263 | .BR "\-\-live [USEC]" |
0794f51b DG |
264 | Set the session exclusively in live mode. The paremeter is the delay in micro |
265 | seconds before the data is flushed and streamed. The live mode allows you to | |
266 | stream the trace and view it while it's being recorded by any tracer. For that, | |
267 | you need a lttng-relayd and this session requires a network URL (\-U or | |
d73c5802 DG |
268 | \-C/\-D). If no USEC nor URL is provided, the default is to use a timer value |
269 | set to 1000000 and the network URL set to net://127.0.0.1. | |
0794f51b DG |
270 | |
271 | To read a live session, you can use babeltrace(1) or the live streaming | |
272 | protocol in doc/live-reading-protocol.txt. Here is an example: | |
273 | ||
274 | .nf | |
275 | $ lttng-relayd -o /tmp/lttng | |
276 | $ lttng create --live 200000 -U net://localhost | |
277 | $ lttng enable-event -a --userspace | |
278 | $ lttng start | |
279 | .fi | |
280 | ||
281 | After the start, you'll be able to read the events while they are being | |
282 | recorded in /tmp/lttng. | |
6b8f2e64 | 283 | |
ee2758e5 MD |
284 | .TP |
285 | .BR "\-U, \-\-set-url=URL" | |
286 | Set URL for the consumer output destination. It is persistent for the | |
287 | session lifetime. Redo the command to change it. This will set both data | |
288 | and control URL for network. | |
289 | .TP | |
290 | .BR "\-C, \-\-ctrl-url=URL" | |
291 | Set control path URL. (Must use -D also) | |
292 | .TP | |
293 | .BR "\-D, \-\-data-url=URL" | |
294 | Set data path URL. (Must use -C also) | |
295 | .PP | |
6b8f2e64 DG |
296 | Using these options, each API call can be controlled individually. For |
297 | instance, \-C does not enable the consumer automatically. You'll need the \-e | |
298 | option for that. | |
299 | ||
785d2d0d DG |
300 | .B URL FORMAT: |
301 | ||
302 | proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] | |
303 | ||
304 | Supported protocols are (proto): | |
ee2758e5 MD |
305 | .TP |
306 | .BR "file://..." | |
307 | Local filesystem full path. | |
785d2d0d | 308 | |
ee2758e5 MD |
309 | .TP |
310 | .BR "net://..." | |
311 | This will use the default network transport layer which is TCP for both | |
312 | control (PORT1) and data port (PORT2). The default ports are | |
313 | respectively 5342 and 5343. Note that net[6]:// is not yet supported. | |
785d2d0d | 314 | |
ee2758e5 MD |
315 | .TP |
316 | .BR "tcp[6]://..." | |
317 | Can only be used with -C and -D together | |
785d2d0d DG |
318 | |
319 | NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732) | |
6b8f2e64 DG |
320 | |
321 | .B EXAMPLES: | |
322 | ||
ee2758e5 | 323 | .nf |
6b8f2e64 | 324 | # lttng create -U net://192.168.1.42 |
ee2758e5 | 325 | .fi |
6b8f2e64 DG |
326 | Uses TCP and default ports for the given destination. |
327 | ||
ee2758e5 | 328 | .nf |
6b8f2e64 | 329 | # lttng create -U net6://[fe80::f66d:4ff:fe53:d220] |
ee2758e5 | 330 | .fi |
6b8f2e64 DG |
331 | Uses TCP, default ports and IPv6. |
332 | ||
ee2758e5 | 333 | .nf |
6b8f2e64 | 334 | # lttng create s1 -U net://myhost.com:3229 |
6991b181 | 335 | .fi |
ee2758e5 MD |
336 | Create session s1 and set its consumer to myhost.com on port 3229 for control. |
337 | .RE | |
338 | .PP | |
6991b181 | 339 | |
f2b14ef1 MD |
340 | .PP |
341 | \fBdestroy\fP [NAME] [OPTIONS] | |
342 | .RS | |
6991b181 DG |
343 | Teardown tracing session |
344 | ||
345 | Free memory on the session daemon and tracer side. It's gone! | |
346 | ||
347 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
348 | |
349 | .B OPTIONS: | |
350 | ||
f2b14ef1 MD |
351 | .TP |
352 | .BR "\-h, \-\-help" | |
353 | Show summary of possible options and commands. | |
354 | .TP | |
355 | .BR "\-a, \-\-all" | |
356 | Destroy all sessions | |
357 | .TP | |
358 | .BR "\-\-list-options" | |
359 | Simple listing of options | |
360 | .RE | |
361 | .PP | |
6991b181 | 362 | |
05be3802 MD |
363 | .PP |
364 | \fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
365 | .RS | |
6991b181 DG |
366 | Enable tracing channel |
367 | ||
004f3466 DG |
368 | To enable an event, you must enable both the event and the channel that |
369 | contains it. | |
b883c01b | 370 | |
c9e32613 | 371 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 372 | file. |
7972aab2 | 373 | |
05be3802 MD |
374 | Exactly one of \-k or -u must be specified. |
375 | ||
7972aab2 | 376 | It is important to note that if a certain type of buffers is used, the session |
bd337b98 | 377 | will be set with that type and all other subsequent channel needs to have the |
7972aab2 | 378 | same type. |
bd337b98 | 379 | |
d2f11c4a DG |
380 | Note that once the session has been started and enabled on the tracer side, |
381 | it's not possible anymore to enable a new channel for that session. | |
6991b181 DG |
382 | |
383 | .B OPTIONS: | |
384 | ||
05be3802 MD |
385 | .TP |
386 | .BR "\-h, \-\-help" | |
387 | Show this help | |
388 | .TP | |
389 | .BR "\-\-list-options" | |
390 | Simple listing of options | |
391 | .TP | |
392 | .BR "\-s, \-\-session NAME" | |
393 | Apply on session name | |
394 | .TP | |
395 | .BR "\-k, \-\-kernel" | |
396 | Apply to the kernel tracer | |
397 | .TP | |
398 | .BR "\-u, \-\-userspace" | |
399 | Apply to the user-space tracer | |
400 | .TP | |
401 | .BR "\-\-discard" | |
402 | Discard event when subbuffers are full (default) | |
403 | .TP | |
404 | .BR "\-\-overwrite" | |
405 | Flight recorder mode : overwrites events when subbuffers are full | |
406 | .TP | |
407 | .BR "\-\-subbuf-size SIZE" | |
408 | Subbuffer size in bytes {+k,+M,+G}. | |
409 | (default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096) | |
410 | Rounded up to the next power of 2. | |
411 | ||
412 | The minimum subbuffer size, for each tracer, is the max value between | |
413 | the default above and the system page size. You can issue this command | |
414 | to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP | |
415 | .TP | |
416 | .BR "\-\-num-subbuf NUM" | |
417 | Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4, | |
418 | metadata: 2) Rounded up to the next power of 2. | |
419 | .TP | |
420 | .BR "\-\-switch-timer USEC" | |
421 | Switch subbuffer timer interval in µsec. | |
422 | (default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0) | |
423 | .TP | |
424 | .BR "\-\-read-timer USEC" | |
425 | Read timer interval in µsec. | |
426 | (default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0) | |
427 | .TP | |
428 | .BR "\-\-output TYPE" | |
429 | Channel output type. Possible values: mmap, splice | |
430 | (default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap) | |
431 | .TP | |
432 | .BR "\-\-buffers-uid" | |
433 | Use per UID buffer (\-u only). Buffers are shared between applications | |
434 | that have the same UID. | |
435 | .TP | |
436 | .BR "\-\-buffers-pid" | |
437 | Use per PID buffer (\-u only). Each application has its own buffers. | |
438 | .TP | |
439 | .BR "\-\-buffers-global" | |
440 | Use shared buffer for the whole system (\-k only) | |
441 | .TP | |
442 | .BR "\-C, \-\-tracefile-size SIZE" | |
443 | Maximum size of each tracefile within a stream (in bytes). | |
444 | 0 means unlimited. (default: 0) | |
445 | .TP | |
446 | .BR "\-W, \-\-tracefile-count COUNT" | |
447 | Used in conjunction with \-C option, this will limit the number of files | |
448 | created to the specified count. 0 means unlimited. (default: 0) | |
1624d5b7 JD |
449 | |
450 | .B EXAMPLES: | |
451 | ||
05be3802 MD |
452 | .nf |
453 | $ lttng enable-channel -k -C 4096 -W 32 chan1 | |
454 | .fi | |
e256d661 | 455 | For each stream, the maximum size of each trace file will be 4096 bytes and |
cea28771 | 456 | there will be a maximum of 32 different files. The file count is appended after |
1624d5b7 JD |
457 | the stream number as seen in the following example. The last trace file is |
458 | smaller than 4096 since it was not completely filled. | |
459 | ||
05be3802 | 460 | .nf |
1624d5b7 JD |
461 | ~/lttng-traces/[...]/chan1_0_0 (4096) |
462 | ~/lttng-traces/[...]/chan1_0_1 (4096) | |
463 | ~/lttng-traces/[...]/chan1_0_2 (3245) | |
464 | ~/lttng-traces/[...]/chan1_1_0 (4096) | |
465 | ... | |
05be3802 | 466 | .fi |
1624d5b7 | 467 | |
05be3802 MD |
468 | .nf |
469 | $ lttng enable-channel -k -C 4096 | |
470 | .fi | |
1624d5b7 JD |
471 | This will create trace files of 4096 bytes and will create new ones as long as |
472 | there is data available. | |
05be3802 MD |
473 | .RE |
474 | .PP | |
6991b181 | 475 | |
6a240cd9 MD |
476 | .PP |
477 | \fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS] | |
478 | .RS | |
6991b181 DG |
479 | Enable tracing event |
480 | ||
c9e32613 | 481 | A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is |
6991b181 | 482 | omitted, a default channel named '\fBchannel0\fP' is created and the event is |
85076754 MD |
483 | added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default |
484 | channel already exists within the session, an error is returned. For the | |
485 | user-space tracer, using \fB\-a, \-\-all\fP is the same as using the | |
486 | wildcard "*". | |
6991b181 | 487 | |
c9e32613 | 488 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 489 | file. |
6991b181 DG |
490 | |
491 | .B OPTIONS: | |
492 | ||
6a240cd9 MD |
493 | .TP |
494 | .BR "\-h, \-\-help" | |
495 | Show summary of possible options and commands. | |
496 | .TP | |
497 | .BR "\-\-list-options" | |
498 | Simple listing of options | |
499 | .TP | |
500 | .BR "\-s, \-\-session NAME" | |
501 | Apply on session name | |
502 | .TP | |
503 | .BR "\-c, \-\-channel NAME" | |
504 | Apply on channel name | |
505 | .TP | |
506 | .BR "\-a, \-\-all" | |
e256d661 | 507 | Enable all tracepoints and syscalls. This actually enables a single |
6a240cd9 MD |
508 | wildcard event "*". |
509 | .TP | |
510 | .BR "\-k, \-\-kernel" | |
511 | Apply for the kernel tracer | |
512 | .TP | |
513 | .BR "\-u, \-\-userspace" | |
514 | Apply for the user-space tracer | |
515 | .TP | |
bed69e7d DG |
516 | .BR "\-j, \-\-jul" |
517 | Apply for Java application using Java Util Logging interface (JUL) | |
518 | .TP | |
6a240cd9 | 519 | .BR "\-\-tracepoint" |
e256d661 | 520 | Tracepoint event (default). Userspace tracer supports wildcards at the end |
6a240cd9 MD |
521 | of string. Don't forget to quote to deal with bash expansion. |
522 | e.g.: | |
6991b181 | 523 | .nf |
6991b181 DG |
524 | "*" |
525 | "app_component:na*" | |
6991b181 | 526 | .fi |
6a240cd9 MD |
527 | .TP |
528 | .BR "\-\-loglevel NAME" | |
529 | Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h). | |
f9e8873b DG |
530 | For the JUL domain, the loglevel ranges are detailed with the \-\-help |
531 | option thus starting from SEVERE to FINEST. | |
6a240cd9 MD |
532 | .TP |
533 | .BR "\-\-loglevel-only NAME" | |
534 | Tracepoint loglevel (only this loglevel). | |
535 | The loglevel or loglevel-only options should be combined with a | |
536 | tracepoint name or tracepoint wildcard. | |
537 | .TP | |
538 | .BR "\-\-probe (addr | symbol | symbol+offset)" | |
539 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) | |
540 | or hexadecimal (0xNNN...) | |
541 | .TP | |
542 | .BR "\-\-function (addr | symbol | symbol+offset)" | |
543 | Dynamic function entry/return probe. Addr and offset can be octal | |
544 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) | |
545 | .TP | |
546 | .BR "\-\-syscall" | |
547 | System call event. Enabling syscalls tracing (kernel tracer), you will | |
548 | not be able to disable them with disable-event. This is a known | |
627dbfd8 CB |
549 | limitation. You can disable the entire channel to do the trick. Also note |
550 | that per-syscall selection is not supported yet. Use with "-a" to enable | |
551 | all syscalls. | |
6a240cd9 MD |
552 | .TP |
553 | .BR "\-\-filter 'expression'" | |
554 | Set a filter on a newly enabled event. Filter expression on event | |
e256d661 JG |
555 | fields and context. The event will be recorded if the filter's |
556 | expression evaluates to TRUE. Only specify on first activation of a | |
557 | given event within a session. | |
558 | Specifying a filter is only allowed when enabling events within a session before | |
6a240cd9 MD |
559 | tracing is started. If the filter fails to link with the event |
560 | within the traced domain, the event will be discarded. | |
e256d661 | 561 | Filtering is currently only implemented for the user-space tracer. |
6a240cd9 MD |
562 | |
563 | Expression examples: | |
564 | ||
565 | .nf | |
566 | 'intfield > 500 && intfield < 503' | |
567 | '(strfield == "test" || intfield != 10) && intfield > 33' | |
568 | 'doublefield > 1.1 && intfield < 5.3' | |
569 | .fi | |
570 | ||
571 | Wildcards are allowed at the end of strings: | |
572 | 'seqfield1 == "te*"' | |
573 | In string literals, the escape character is a '\\'. Use '\\*' for | |
e256d661 JG |
574 | the '*' character, and '\\\\' for the '\\' character sequence. Wildcard |
575 | matches any sequence of characters, including an empty sub-string | |
576 | (matches 0 or more characters). | |
6a240cd9 | 577 | |
e256d661 JG |
578 | Context information can be used for filtering. The examples below shows |
579 | usage of context filtering on the process name (using a wildcard), process ID | |
580 | range, and unique thread ID. The process and thread IDs of | |
6a240cd9 MD |
581 | running applications can be found under columns "PID" and "LWP" of the |
582 | "ps -eLf" command. | |
583 | ||
584 | .nf | |
585 | '$ctx.procname == "demo*"' | |
586 | '$ctx.vpid >= 4433 && $ctx.vpid < 4455' | |
587 | '$ctx.vtid == 1234' | |
588 | .fi | |
589 | ||
bccd20a3 JI |
590 | .TP |
591 | .BR "\-x, \-\-exclude LIST" | |
592 | Add exclusions to UST tracepoints: | |
593 | Events that match any of the items in the comma-separated LIST are not | |
594 | enabled, even if they match a wildcard definition of the event. | |
595 | ||
596 | This option is also applicable with the \fB\-a, \-\-all\fP option, | |
597 | in which case all UST tracepoints are enabled except the ones whose | |
598 | names match any of the items in LIST. | |
6a240cd9 MD |
599 | .RE |
600 | .PP | |
6991b181 | 601 | |
272c6a17 MD |
602 | .PP |
603 | \fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
604 | .RS | |
6991b181 DG |
605 | Disable tracing channel |
606 | ||
e256d661 | 607 | Disabling a channel disables the tracing of all of the channel's events. A channel |
5368d366 | 608 | can be re-enabled by calling \fBlttng enable-channel NAME\fP again. |
6991b181 | 609 | |
c9e32613 | 610 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 611 | file. |
6991b181 DG |
612 | |
613 | .B OPTIONS: | |
614 | ||
272c6a17 MD |
615 | .TP |
616 | .BR "\-h, \-\-help" | |
617 | Show summary of possible options and commands. | |
618 | .TP | |
619 | .BR "\-\-list-options" | |
620 | Simple listing of options | |
621 | .TP | |
622 | .BR "\-s, \-\-session NAME" | |
623 | Apply on session name | |
624 | .TP | |
625 | .BR "\-k, \-\-kernel" | |
626 | Apply for the kernel tracer | |
627 | .TP | |
628 | .BR "\-u, \-\-userspace" | |
629 | Apply for the user-space tracer | |
630 | .RE | |
631 | .PP | |
6991b181 | 632 | |
c138a39b MD |
633 | .PP |
634 | \fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS] | |
635 | .RS | |
6991b181 DG |
636 | Disable tracing event |
637 | ||
638 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event | |
639 | NAME\fP again. | |
640 | ||
c9e32613 | 641 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
6991b181 | 642 | file. |
6991b181 | 643 | |
85076754 MD |
644 | If \fB\-c, \-\-channel\fP is omitted, the default channel name is used. |
645 | If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already | |
646 | exists within the session, an error is returned. | |
647 | ||
6991b181 DG |
648 | .B OPTIONS: |
649 | ||
c138a39b MD |
650 | .TP |
651 | .BR "\-h, \-\-help" | |
652 | Show summary of possible options and commands. | |
653 | .TP | |
654 | .BR "\-\-list-options" | |
655 | Simple listing of options | |
656 | .TP | |
657 | .BR "\-s, \-\-session NAME" | |
658 | Apply on session name | |
659 | .TP | |
85076754 MD |
660 | .BR "\-c, \-\-channel NAME" |
661 | Apply on channel name | |
662 | .TP | |
c138a39b MD |
663 | .BR "\-a, \-\-all-events" |
664 | Disable all events. This does NOT disable "*" but rather every known | |
665 | events of the session. | |
666 | .TP | |
667 | .BR "\-k, \-\-kernel" | |
668 | Apply for the kernel tracer | |
669 | .TP | |
670 | .BR "\-u, \-\-userspace" | |
671 | Apply for the user-space tracer | |
bed69e7d DG |
672 | .TP |
673 | .BR "\-j, \-\-jul" | |
674 | Apply for Java application using Java Util Logging interface (JUL) | |
c138a39b MD |
675 | .RE |
676 | .PP | |
6991b181 | 677 | |
747361fe MD |
678 | .PP |
679 | \fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]] | |
680 | .RS | |
c9e32613 | 681 | List tracing session information. |
6991b181 DG |
682 | |
683 | With no arguments, it will list available tracing session(s). | |
684 | ||
fa072eae YB |
685 | With the session name, it will display the details of the session including |
686 | the trace file path, the associated channels and their state (activated | |
d829b38c | 687 | and deactivated), the activated events and more. |
fa072eae | 688 | |
c9e32613 | 689 | With \-k alone, it will list all available kernel events (except the system |
6991b181 | 690 | calls events). |
bed69e7d DG |
691 | With \-j alone, the available JUL event from registered application will be |
692 | list. The event corresponds to the Logger name in the Java JUL application. | |
c9e32613 DG |
693 | With \-u alone, it will list all available user-space events from registered |
694 | applications. Here is an example of 'lttng list \-u': | |
6991b181 | 695 | |
747361fe | 696 | .nf |
6991b181 DG |
697 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello |
698 | ust_tests_hello:tptest_sighandler (type: tracepoint) | |
699 | ust_tests_hello:tptest (type: tracepoint) | |
747361fe | 700 | .fi |
6991b181 DG |
701 | |
702 | You can now enable any event listed by using the name : | |
703 | \fBust_tests_hello:tptest\fP. | |
6991b181 DG |
704 | |
705 | .B OPTIONS: | |
706 | ||
747361fe MD |
707 | .TP |
708 | .BR "\-h, \-\-help" | |
709 | Show summary of possible options and commands. | |
710 | .TP | |
711 | .BR "\-\-list-options" | |
712 | Simple listing of options | |
713 | .TP | |
714 | .BR "\-k, \-\-kernel" | |
715 | Select kernel domain | |
716 | .TP | |
717 | .BR "\-u, \-\-userspace" | |
718 | Select user-space domain. | |
bed69e7d DG |
719 | .TP |
720 | .BR "\-j, \-\-jul" | |
721 | Apply for Java application using JUL | |
722 | .TP | |
723 | .BR "\-f, \-\-fields" | |
724 | List event fields | |
6991b181 | 725 | |
747361fe | 726 | .PP |
6b8f2e64 DG |
727 | .B SESSION OPTIONS: |
728 | ||
747361fe MD |
729 | .TP |
730 | .BR "\-c, \-\-channel NAME" | |
731 | List details of a channel | |
732 | .TP | |
733 | .BR "\-d, \-\-domain" | |
734 | List available domain(s) | |
735 | .RE | |
736 | .PP | |
6991b181 | 737 | |
7c96a096 MD |
738 | .PP |
739 | \fBset-session\fP NAME [OPTIONS] | |
740 | .RS | |
6991b181 DG |
741 | Set current session name |
742 | ||
743 | Will change the session name in the .lttngrc file. | |
6991b181 DG |
744 | |
745 | .B OPTIONS: | |
746 | ||
7c96a096 MD |
747 | .TP |
748 | .BR "\-h, \-\-help" | |
749 | Show summary of possible options and commands. | |
750 | .TP | |
751 | .BR "\-\-list-options" | |
752 | Simple listing of options | |
753 | .RE | |
754 | .PP | |
6991b181 | 755 | |
8df3bfe9 MD |
756 | .PP |
757 | \fBsnapshot\fP [OPTIONS] ACTION | |
758 | .RS | |
b872baea | 759 | Snapshot command for LTTng session. |
b872baea DG |
760 | |
761 | .B OPTIONS: | |
762 | ||
8df3bfe9 MD |
763 | .TP |
764 | .BR "\-h, \-\-help" | |
765 | Show summary of possible options and commands. | |
766 | .TP | |
767 | .BR "\-\-list-options" | |
768 | Simple listing of options | |
b872baea | 769 | |
8df3bfe9 | 770 | .PP |
b872baea DG |
771 | .B ACTION: |
772 | ||
8df3bfe9 | 773 | .TP |
b872baea DG |
774 | \fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL> |
775 | ||
776 | Setup and add an snapshot output for a session. Output are the destination | |
777 | where the snapshot will be sent. Only one output is permitted. To change it, | |
778 | you'll need to delete it and add back the new one. | |
779 | ||
8df3bfe9 | 780 | .TP |
b872baea DG |
781 | \fBdel-output\fP ID | NAME [-s <NAME>] |
782 | ||
783 | Delete an output for a session using the ID. You can either specify the | |
784 | output's ID that can be found with list-output or the name. | |
785 | ||
8df3bfe9 | 786 | .TP |
b872baea DG |
787 | \fBlist-output\fP [-s <NAME>] |
788 | ||
789 | List the output of a session. Attributes of the output are printed. | |
790 | ||
8df3bfe9 | 791 | .TP |
b872baea DG |
792 | \fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>] |
793 | ||
794 | Snapshot a session's buffer(s) for all domains. If an URL is specified, it is | |
795 | used instead of a previously added output. Specifying only a name or/and a max | |
796 | size will override the current output values. For instance, you can record a | |
797 | snapshot with a custom maximum size or with a different name. | |
798 | ||
8df3bfe9 | 799 | .nf |
1ac1098f | 800 | $ lttng snapshot add-output -n mysnapshot file:///data/snapshot |
b872baea DG |
801 | [...] |
802 | $ lttng snapshot record -n new_name_snapshot | |
8df3bfe9 | 803 | .fi |
b872baea DG |
804 | |
805 | The above will create a snapshot in /data/snapshot/new_name_snapshot* directory | |
806 | rather then in mysnapshot*/ | |
b872baea | 807 | |
8df3bfe9 MD |
808 | .PP |
809 | .B DETAILED ACTION OPTIONS | |
b872baea | 810 | |
8df3bfe9 MD |
811 | .TP |
812 | .BR "\-s, \-\-session NAME" | |
813 | Apply to session name. | |
814 | .TP | |
815 | .BR "\-n, \-\-name NAME" | |
816 | Name of the snapshot's output. | |
817 | .TP | |
818 | .BR "\-m, \-\-max-size SIZE" | |
a8f307d8 SM |
819 | Maximum size in bytes of the snapshot. The maxium size does not include the |
820 | metadata file. Human readable format is accepted: {+k,+M,+G}. For instance, | |
821 | \-\-max-size 5M | |
8df3bfe9 MD |
822 | .TP |
823 | .BR "\-C, \-\-ctrl-url URL" | |
824 | Set control path URL. (Must use -D also) | |
825 | .TP | |
826 | .BR "\-D, \-\-data-url URL" | |
827 | Set data path URL. (Must use -C also) | |
828 | .RE | |
829 | .PP | |
b872baea | 830 | |
afb8ca1b MD |
831 | .PP |
832 | \fBstart\fP [NAME] [OPTIONS] | |
833 | .RS | |
6991b181 DG |
834 | Start tracing |
835 | ||
836 | It will start tracing for all tracers for a specific tracing session. | |
6991b181 | 837 | If NAME is omitted, the session name is taken from the .lttngrc file. |
6991b181 DG |
838 | |
839 | .B OPTIONS: | |
840 | ||
afb8ca1b MD |
841 | .TP |
842 | .BR "\-h, \-\-help" | |
843 | Show summary of possible options and commands. | |
844 | .TP | |
845 | .BR "\-\-list-options" | |
846 | Simple listing of options | |
847 | .RE | |
848 | .PP | |
6991b181 | 849 | |
6c09bfdb MD |
850 | .PP |
851 | \fBstop\fP [NAME] [OPTIONS] | |
852 | .RS | |
6991b181 DG |
853 | Stop tracing |
854 | ||
391b9c72 DG |
855 | It will stop tracing for all tracers for a specific tracing session. Before |
856 | returning, the command checks for data availability meaning that it will wait | |
857 | until the trace is readable for the session. Use \-\-no-wait to avoid this | |
858 | behavior. | |
6991b181 DG |
859 | |
860 | If NAME is omitted, the session name is taken from the .lttngrc file. | |
6991b181 DG |
861 | |
862 | .B OPTIONS: | |
863 | ||
6c09bfdb MD |
864 | .TP |
865 | .BR "\-h, \-\-help" | |
866 | Show summary of possible options and commands. | |
867 | .TP | |
868 | .BR "\-\-list-options" | |
869 | Simple listing of options | |
3a7a166e MJ |
870 | .TP |
871 | .BR "\-\-no-wait" | |
6c09bfdb MD |
872 | Don't wait for data availability. |
873 | .RE | |
874 | .PP | |
6991b181 | 875 | |
5975c30a MD |
876 | .PP |
877 | \fBversion\fP | |
878 | .RS | |
6991b181 | 879 | Show version information |
6991b181 DG |
880 | |
881 | .B OPTIONS: | |
882 | ||
5975c30a MD |
883 | .TP |
884 | .BR "\-h, \-\-help" | |
885 | Show summary of possible options and commands. | |
886 | .TP | |
887 | .BR "\-\-list-options" | |
888 | Simple listing of options | |
889 | .RE | |
890 | .PP | |
6991b181 | 891 | |
5b4c1410 MD |
892 | .PP |
893 | \fBview\fP [SESSION_NAME] [OPTIONS] | |
894 | .RS | |
895 | View traces of a tracing session. By default, the babeltrace viewer | |
896 | will be used for text viewing. If SESSION_NAME is omitted, the session | |
897 | name is taken from the .lttngrc file. | |
6991b181 DG |
898 | |
899 | .B OPTIONS: | |
900 | ||
5b4c1410 MD |
901 | .TP |
902 | .BR "\-h, \-\-help" | |
903 | Show this help | |
904 | .TP | |
905 | .BR "\-\-list-options" | |
906 | Simple listing of options | |
907 | .TP | |
908 | .BR "\-t, \-\-trace-path PATH" | |
909 | Trace directory path for the viewer | |
910 | .TP | |
911 | .BR "\-e, \-\-viewer CMD" | |
912 | Specify viewer and/or options to use This will completely override the | |
913 | default viewers so please make sure to specify the full command. The | |
914 | trace directory path of the session will be appended at the end to the | |
915 | arguments | |
916 | .RE | |
917 | .PP | |
6991b181 | 918 | |
acf47627 DG |
919 | .SH "JUL DOMAIN" |
920 | This section explains the JUL domain (\-j, \-\-jul) where JUL stands for Java | |
921 | Util Logging. You can use that feature by using the \fBliblttng-ust-jul.so\fP | |
922 | from the lttng-ust(3) project. | |
923 | ||
924 | The LTTng Java Agent uses JNI to link the UST tracer to the Java application | |
925 | that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When | |
926 | enabling events with the JUL domain, you enable a Logger name that will then be | |
927 | mapped to a default UST tracepoint called \fBlttng_jul:jul_event\fP in the | |
928 | \fBlttng_jul_channel\fP. Using the lttng-ctl API, any JUL events must use the | |
929 | tracepoint event type (same as \-\-tracepoint). | |
930 | ||
931 | Because of the default immutable channel (\fBlttng_jul_channel\fP), the | |
932 | \fBenable-channel\fP command CAN NOT be used with the JUL domain thus not | |
933 | having any \-j option. | |
934 | ||
935 | For JUL event, loglevels are supported with the JUL ABI values. Use \fBlttng | |
936 | enable-event \-h\fP to list them. Wildcards are NOT supported except the "*" | |
937 | meaning all events (same as \-a). | |
938 | ||
939 | Exactly like the UST domain, if the Java application has the same UID as you, | |
940 | you can trace it. Same goes for the tracing group accessing root applications. | |
941 | ||
942 | Finally, you can list every Logger name that are available from JUL registered | |
943 | applications to the session daemon by using \fBlttng list \-j\fP. | |
944 | ||
945 | Here is an example on how to use this domain. | |
946 | ||
947 | .nf | |
948 | $ lttng list -j | |
949 | [...] | |
950 | $ lttng create aSession | |
951 | $ lttng enable-event -s aSession -j MyCustomLoggerName | |
952 | $ lttng start | |
953 | .fi | |
954 | ||
955 | More information can be found in the lttng-ust documentation, see | |
956 | java-util-logging.txt | |
957 | .PP | |
958 | ||
c206d957 | 959 | .SH "EXIT VALUES" |
b107a0b1 | 960 | .PP |
6b8f2e64 DG |
961 | On success 0 is returned and a positive value on error. Value of 1 means a command |
962 | error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that | |
963 | something went wrong during the command. | |
c206d957 | 964 | |
6b8f2e64 | 965 | Any other value above 10, please refer to |
b107a0b1 | 966 | .BR "<lttng/lttng-error.h>" |
6b8f2e64 DG |
967 | for a detailed list or use lttng_strerror() to get a human readable string of |
968 | the error code. | |
c206d957 | 969 | .PP |
b107a0b1 | 970 | |
6991b181 DG |
971 | .SH "ENVIRONMENT VARIABLES" |
972 | ||
973 | .PP | |
974 | Note that all command line options override environment variables. | |
975 | .PP | |
976 | ||
977 | .PP | |
05833633 | 978 | .IP "LTTNG_SESSIOND_PATH" |
c9e32613 DG |
979 | Allows one to specify the full session daemon binary path to lttng command line |
980 | tool. You can also use \-\-sessiond-path option having the same effect. | |
b107a0b1 MD |
981 | .PP |
982 | ||
6991b181 | 983 | .SH "SEE ALSO" |
6b8f2e64 DG |
984 | .BR babeltrace(1), |
985 | .BR lttng-ust(3), | |
986 | .BR lttng-sessiond(8), | |
987 | .BR lttng-relayd(8), | |
b107a0b1 | 988 | |
6991b181 DG |
989 | .SH "BUGS" |
990 | ||
b107a0b1 | 991 | .PP |
6991b181 | 992 | If you encounter any issues or usability problem, please report it on our |
6b8f2e64 DG |
993 | mailing list <lttng-dev@lists.lttng.org> to help improve this project or |
994 | at https://bugs.lttng.org which is a bugtracker. | |
b107a0b1 MD |
995 | .PP |
996 | ||
6991b181 DG |
997 | .SH "CREDITS" |
998 | ||
999 | .PP | |
c9e32613 | 1000 | lttng is distributed under the GNU General Public License version 2. See the file |
6991b181 DG |
1001 | COPYING for details. |
1002 | .PP | |
1003 | A Web site is available at http://lttng.org for more information on the LTTng | |
1004 | project. | |
1005 | .PP | |
1006 | You can also find our git tree at http://git.lttng.org. | |
1007 | .PP | |
1008 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. | |
1009 | .PP | |
1010 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. | |
1011 | .PP | |
1012 | .SH "THANKS" | |
1013 | ||
1014 | .PP | |
1015 | Thanks to Yannick Brosseau without whom this project would never have been so | |
1016 | lean and mean! Also thanks to the Ericsson teams working on tracing which | |
fa072eae | 1017 | helped us greatly with detailed bug reports and unusual test cases. |
6991b181 DG |
1018 | |
1019 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA | |
1020 | maintainer) and Jon Bernard for our Debian packages. | |
1021 | ||
1022 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de | |
1023 | Montreal for the LTTng journey. | |
c9e32613 | 1024 | .PP |
6991b181 DG |
1025 | .SH "AUTHORS" |
1026 | ||
1027 | .PP | |
1028 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and | |
1029 | David Goulet. More people have since contributed to it. It is currently | |
1030 | maintained by David Goulet <dgoulet@efficios.com>. | |
1031 | .PP |