| 1 | .TH "LTTNG" "1" "February 9, 2012" "" "" |
| 2 | |
| 3 | .SH "NAME" |
| 4 | lttng \(em LTTng 2.0 tracer control command line tool |
| 5 | |
| 6 | .SH "SYNOPSIS" |
| 7 | |
| 8 | .PP |
| 9 | .nf |
| 10 | lttng [OPTIONS] <COMMAND> |
| 11 | .fi |
| 12 | .SH "DESCRIPTION" |
| 13 | |
| 14 | .PP |
| 15 | The LTTng project aims at providing highly efficient tracing tools for Linux. |
| 16 | It's tracers help tracking down performance issues and debugging problems |
| 17 | involving multiple concurrent processes and threads. Tracing across multiple |
| 18 | systems is also possible. |
| 19 | |
| 20 | The \fBlttng\fP command line tool from the lttng-tools package is used to control |
| 21 | both kernel and user-space tracing. Every interactions with the tracer should |
| 22 | be done by this tool or by the liblttng-ctl provided with the lttng-tools |
| 23 | package. |
| 24 | |
| 25 | LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry, |
| 26 | which permits you to interact with multiple tracers (kernel and user-space) |
| 27 | inside the same container, a tracing session. Traces can be gathered from the |
| 28 | kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading |
| 29 | those traces is done using the babeltrace(1) text viewer. |
| 30 | |
| 31 | In order to trace the kernel, the session daemon needs to be running as root. |
| 32 | LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is |
| 33 | in that group can interact with the root session daemon and thus trace the |
| 34 | kernel. Session daemons can co-exist meaning that you can have a session daemon |
| 35 | running as Alice that can be used to trace her applications along side with a |
| 36 | root daemon or even a Bob daemon. We highly recommend to start the session |
| 37 | daemon at boot time for stable and long term tracing. |
| 38 | |
| 39 | Every user-space applications instrumented with lttng-ust(3), will |
| 40 | automatically register to the session daemon. This feature gives you the |
| 41 | ability to list available traceable applications and tracepoints on a per user |
| 42 | basis. (See \fBlist\fP command). |
| 43 | .SH "OPTIONS" |
| 44 | |
| 45 | .PP |
| 46 | This program follow the usual GNU command line syntax with long options starting with |
| 47 | two dashes. Below is a summary of the available options. |
| 48 | .PP |
| 49 | |
| 50 | .TP |
| 51 | .BR "\-h, \-\-help" |
| 52 | Show summary of possible options and commands. |
| 53 | .TP |
| 54 | .BR "\-v, \-\-verbose" |
| 55 | Increase verbosity. |
| 56 | Three levels of verbosity are available which are triggered by putting additional v to |
| 57 | the option (\-vv or \-vvv) |
| 58 | .TP |
| 59 | .BR "\-q, \-\-quiet" |
| 60 | Suppress all messages (even errors). |
| 61 | .TP |
| 62 | .BR "\-g, \-\-group NAME" |
| 63 | Set unix tracing group name. (default: tracing) |
| 64 | .TP |
| 65 | .BR "\-n, \-\-no-sessiond" |
| 66 | Don't automatically spawn a session daemon. |
| 67 | .TP |
| 68 | .BR "\-\-sessiond\-path" |
| 69 | Set session daemon full binary path. |
| 70 | .TP |
| 71 | .BR "\-\-list\-options" |
| 72 | Simple listing of lttng options. |
| 73 | .TP |
| 74 | .BR "\-\-list\-commands" |
| 75 | Simple listing of lttng commands. |
| 76 | .SH "COMMANDS" |
| 77 | |
| 78 | .TP |
| 79 | \fBadd-context\fP |
| 80 | .nf |
| 81 | Add context to event(s) and/or channel(s). |
| 82 | |
| 83 | A context is basically extra information appended to a channel or event. For |
| 84 | instance, you could ask the tracer to add the PID information within the |
| 85 | "sched_switch" kernel event. You can also add performance monitoring unit |
| 86 | counters (perf PMU) using the perf kernel API). |
| 87 | |
| 88 | For example, this command will add the context information 'prio' and two perf |
| 89 | counters (hardware branch misses and cache misses), to all events in the trace |
| 90 | data output: |
| 91 | |
| 92 | # lttng add-context \-k \-t prio \-t perf:branch-misses \-t perf:cache-misses |
| 93 | |
| 94 | Please take a look at the help (\-h/\-\-help) for a detailed list of available |
| 95 | contexts. |
| 96 | |
| 97 | If no channel and no event is given (\-c/\-e), the context is added to all |
| 98 | channels (which applies automatically to all events in that channel). Otherwise |
| 99 | the context will be added only to the channel (\-c) and/or event (\-e) indicated. |
| 100 | |
| 101 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
| 102 | file. |
| 103 | .fi |
| 104 | |
| 105 | .B OPTIONS: |
| 106 | |
| 107 | .nf |
| 108 | \-h, \-\-help |
| 109 | Show summary of possible options and commands. |
| 110 | \-s, \-\-session NAME |
| 111 | Apply on session name. |
| 112 | \-c, \-\-channel NAME |
| 113 | Apply on channel name. |
| 114 | \-e, \-\-event NAME |
| 115 | Apply on event name. |
| 116 | \-k, \-\-kernel |
| 117 | Apply for the kernel tracer |
| 118 | \-u, \-\-userspace |
| 119 | Apply for the user-space tracer |
| 120 | \-t, \-\-type TYPE |
| 121 | Context type. You can repeat this option on the command line. Please |
| 122 | use "lttng add-context \-h" to list all available types. |
| 123 | .fi |
| 124 | |
| 125 | .IP |
| 126 | |
| 127 | .IP "\fBcalibrate\fP" |
| 128 | .nf |
| 129 | Quantify LTTng overhead |
| 130 | |
| 131 | The LTTng calibrate command can be used to find out the combined average |
| 132 | overhead of the LTTng tracer and the instrumentation mechanisms used. This |
| 133 | overhead can be calibrated in terms of time or using any of the PMU performance |
| 134 | counter available on the system. |
| 135 | |
| 136 | For now, the only calibration implemented is that of the kernel function |
| 137 | instrumentation (kretprobes). |
| 138 | |
| 139 | * Calibrate kernel function instrumentation |
| 140 | |
| 141 | Let's use an example to show this calibration. We use an i7 processor with 4 |
| 142 | general-purpose PMU registers. This information is available by issuing dmesg, |
| 143 | looking for "generic registers". |
| 144 | |
| 145 | This sequence of commands will gather a trace executing a kretprobe hooked on |
| 146 | an empty function, gathering PMU counters LLC (Last Level Cache) misses |
| 147 | information (see lttng add-context \-\-help to see the list of available PMU |
| 148 | counters). |
| 149 | |
| 150 | # lttng create calibrate-function |
| 151 | # lttng enable-event calibrate \-\-kernel \-\-function lttng_calibrate_kretprobe |
| 152 | # lttng add-context \-\-kernel \-t perf:LLC-load-misses \-t perf:LLC-store-misses \\ |
| 153 | \-t perf:LLC-prefetch-misses |
| 154 | # lttng start |
| 155 | # for a in $(seq 1 10); do \\ |
| 156 | lttng calibrate \-\-kernel \-\-function; |
| 157 | done |
| 158 | # lttng destroy |
| 159 | # babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* | tail \-n 1) |
| 160 | |
| 161 | The output from babeltrace can be saved to a text file and opened in a |
| 162 | spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between |
| 163 | consecutive "calibrate_entry" and "calibrate_return" events. Note that these |
| 164 | counters are per-CPU, so scheduling events would need to be present to account |
| 165 | for migration between CPU. Therefore, for calibration purposes, only events |
| 166 | staying on the same CPU must be considered. |
| 167 | |
| 168 | The average result, for the i7, on 10 samples: |
| 169 | |
| 170 | Average Std.Dev. |
| 171 | perf_LLC_load_misses: 5.0 0.577 |
| 172 | perf_LLC_store_misses: 1.6 0.516 |
| 173 | perf_LLC_prefetch_misses: 9.0 14.742 |
| 174 | |
| 175 | As we can notice, the load and store misses are relatively stable across runs |
| 176 | (their standard deviation is relatively low) compared to the prefetch misses. |
| 177 | We can conclude from this information that LLC load and store misses can be |
| 178 | accounted for quite precisely, but prefetches within a function seems to behave |
| 179 | too erratically (not much causality link between the code executed and the CPU |
| 180 | prefetch activity) to be accounted for. |
| 181 | .fi |
| 182 | |
| 183 | .B OPTIONS: |
| 184 | |
| 185 | .nf |
| 186 | \-h, \-\-help |
| 187 | Show summary of possible options and commands. |
| 188 | \-k, \-\-kernel |
| 189 | Apply for the kernel tracer |
| 190 | \-u, \-\-userspace |
| 191 | Apply for the user-space tracer |
| 192 | \-\-function |
| 193 | Dynamic function entry/return probe (default) |
| 194 | .fi |
| 195 | |
| 196 | .IP |
| 197 | |
| 198 | .IP "\fBcreate\fP [OPTIONS] [NAME] |
| 199 | .nf |
| 200 | Create tracing session. |
| 201 | |
| 202 | A tracing session contains channel(s) which contains event(s). It is domain |
| 203 | agnostic meaning that you can enable channels and events for either the |
| 204 | user-space tracer and/or the kernel tracer. It acts like a container |
| 205 | aggregating multiple tracing sources. |
| 206 | |
| 207 | On creation, a \fB.lttngrc\fP file is created in your $HOME directory |
| 208 | containing the current session name. If NAME is omitted, a session name is |
| 209 | automatically created having this form: 'auto-yyyymmdd-hhmmss'. |
| 210 | |
| 211 | If no \fB\-o, \-\-output\fP is specified, the traces will be written in |
| 212 | $HOME/lttng-traces. |
| 213 | .fi |
| 214 | |
| 215 | .B OPTIONS: |
| 216 | |
| 217 | .nf |
| 218 | \-h, \-\-help |
| 219 | Show summary of possible options and commands. |
| 220 | \-\-list-options |
| 221 | Simple listing of options |
| 222 | \-o, \-\-output PATH |
| 223 | Specify output path for traces |
| 224 | .fi |
| 225 | |
| 226 | .IP |
| 227 | |
| 228 | .IP "\fBdestroy\fP [OPTIONS] [NAME]" |
| 229 | .nf |
| 230 | Teardown tracing session |
| 231 | |
| 232 | Free memory on the session daemon and tracer side. It's gone! |
| 233 | |
| 234 | If NAME is omitted, the session name is taken from the .lttngrc file. |
| 235 | .fi |
| 236 | |
| 237 | .B OPTIONS: |
| 238 | |
| 239 | .nf |
| 240 | \-h, \-\-help |
| 241 | Show summary of possible options and commands. |
| 242 | \-\-list-options |
| 243 | Simple listing of options |
| 244 | .fi |
| 245 | |
| 246 | .IP |
| 247 | |
| 248 | .IP "\fBenable-channel\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]" |
| 249 | .nf |
| 250 | Enable tracing channel |
| 251 | |
| 252 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
| 253 | file. |
| 254 | .fi |
| 255 | |
| 256 | .B OPTIONS: |
| 257 | |
| 258 | .nf |
| 259 | \-h, \-\-help |
| 260 | Show this help |
| 261 | \-\-list-options |
| 262 | Simple listing of options |
| 263 | \-s, \-\-session |
| 264 | Apply on session name |
| 265 | \-k, \-\-kernel |
| 266 | Apply to the kernel tracer |
| 267 | \-u, \-\-userspace |
| 268 | Apply to the user-space tracer |
| 269 | |
| 270 | \-\-discard |
| 271 | Discard event when subbuffers are full (default) |
| 272 | \-\-overwrite |
| 273 | Flight recorder mode : overwrites events when subbuffers are full |
| 274 | \-\-subbuf-size |
| 275 | Subbuffer size in bytes (default: 4096, kernel default: 262144) |
| 276 | \-\-num-subbuf |
| 277 | Number of subbuffers (default: 4) |
| 278 | Needs to be a power of 2 for kernel and ust tracers |
| 279 | \-\-switch-timer |
| 280 | Switch subbuffer timer interval in usec (default: 0) |
| 281 | Needs to be a power of 2 for kernel and ust tracers |
| 282 | \-\-read-timer |
| 283 | Read timer interval in usec (default: 200) |
| 284 | .fi |
| 285 | |
| 286 | .IP |
| 287 | |
| 288 | .IP "\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]" |
| 289 | .nf |
| 290 | Enable tracing event |
| 291 | |
| 292 | A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is |
| 293 | omitted, a default channel named '\fBchannel0\fP' is created and the event is |
| 294 | added to it. For the user-space tracer, using \fB\-a, \-\-all\fP is the same as |
| 295 | using the wildcard "*". |
| 296 | |
| 297 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
| 298 | file. |
| 299 | .fi |
| 300 | |
| 301 | .B OPTIONS: |
| 302 | |
| 303 | .nf |
| 304 | \-h, \-\-help |
| 305 | Show summary of possible options and commands. |
| 306 | \-\-list-options |
| 307 | Simple listing of options |
| 308 | \-s, \-\-session |
| 309 | Apply on session name |
| 310 | \-c, \-\-channel |
| 311 | Apply on channel name |
| 312 | \-a, \-\-all |
| 313 | Enable all tracepoints and syscalls |
| 314 | \-k, \-\-kernel |
| 315 | Apply for the kernel tracer |
| 316 | \-u, \-\-userspace |
| 317 | Apply for the user-space tracer |
| 318 | |
| 319 | \-\-tracepoint |
| 320 | Tracepoint event (default) |
| 321 | - userspace tracer supports wildcards at end of string. Don't forget to |
| 322 | quote to deal with bash expansion. |
| 323 | e.g.: |
| 324 | "*" |
| 325 | "app_component:na*" |
| 326 | \-\-loglevel |
| 327 | Tracepoint loglevel |
| 328 | \-\-probe [addr | symbol | symbol+offset] |
| 329 | Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...) |
| 330 | or hexadecimal (0xNNN...) |
| 331 | \-\-function [addr | symbol | symbol+offset] |
| 332 | Dynamic function entry/return probe. Addr and offset can be octal |
| 333 | (0NNN...), decimal (NNN...) or hexadecimal (0xNNN...) |
| 334 | \-\-syscall |
| 335 | System call event |
| 336 | Enabling syscalls tracing (kernel tracer), you will not be able to disable them |
| 337 | with disable-event. This is a known limitation. You can disable the entire |
| 338 | channel to do the trick. |
| 339 | .fi |
| 340 | |
| 341 | .IP "\fBdisable-channel\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]" |
| 342 | .nf |
| 343 | Disable tracing channel |
| 344 | |
| 345 | Disabling a channel makes all event(s) in that channel to stop tracing. You can |
| 346 | enable it back by calling \fBlttng enable-channel NAME\fP again. |
| 347 | |
| 348 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
| 349 | file. |
| 350 | .fi |
| 351 | |
| 352 | .B OPTIONS: |
| 353 | |
| 354 | .nf |
| 355 | \-h, \-\-help |
| 356 | Show summary of possible options and commands. |
| 357 | \-\-list-options |
| 358 | Simple listing of options |
| 359 | \-s, \-\-session |
| 360 | Apply on session name |
| 361 | \-k, \-\-kernel |
| 362 | Apply for the kernel tracer |
| 363 | \-u, \-\-userspace |
| 364 | Apply for the user-space tracer |
| 365 | .fi |
| 366 | |
| 367 | .IP "\fBdisable-event\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]" |
| 368 | .nf |
| 369 | Disable tracing event |
| 370 | |
| 371 | The event, once disabled, can be re-enabled by calling \fBlttng enable-event |
| 372 | NAME\fP again. |
| 373 | |
| 374 | If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc |
| 375 | file. |
| 376 | .fi |
| 377 | |
| 378 | .B OPTIONS: |
| 379 | |
| 380 | .nf |
| 381 | \-h, \-\-help |
| 382 | Show summary of possible options and commands. |
| 383 | \-\-list-options |
| 384 | Simple listing of options |
| 385 | \-s, \-\-session |
| 386 | Apply on session name |
| 387 | \-k, \-\-kernel |
| 388 | Apply for the kernel tracer |
| 389 | \-u, \-\-userspace |
| 390 | Apply for the user-space tracer |
| 391 | .fi |
| 392 | |
| 393 | .IP "\fBlist\fP [\-k|\-u] [SESSION [SESSION_OPTIONS]]" |
| 394 | .nf |
| 395 | List tracing session information. |
| 396 | |
| 397 | With no arguments, it will list available tracing session(s). |
| 398 | |
| 399 | With the session name, it will display the details of the session including |
| 400 | the trace file path, the associated channels and their state (activated |
| 401 | and deactivated), the activated events and more. |
| 402 | |
| 403 | With \-k alone, it will list all available kernel events (except the system |
| 404 | calls events). |
| 405 | With \-u alone, it will list all available user-space events from registered |
| 406 | applications. Here is an example of 'lttng list \-u': |
| 407 | |
| 408 | PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello |
| 409 | ust_tests_hello:tptest_sighandler (type: tracepoint) |
| 410 | ust_tests_hello:tptest (type: tracepoint) |
| 411 | |
| 412 | You can now enable any event listed by using the name : |
| 413 | \fBust_tests_hello:tptest\fP. |
| 414 | .fi |
| 415 | |
| 416 | .B OPTIONS: |
| 417 | |
| 418 | .nf |
| 419 | \-h, \-\-help |
| 420 | Show summary of possible options and commands. |
| 421 | \-\-list-options |
| 422 | Simple listing of options |
| 423 | \-k, \-\-kernel |
| 424 | Select kernel domain |
| 425 | \-u, \-\-userspace |
| 426 | Select user-space domain. |
| 427 | |
| 428 | Session options: |
| 429 | \-c, \-\-channel NAME |
| 430 | List details of a channel |
| 431 | \-d, \-\-domain |
| 432 | List available domain(s) |
| 433 | .fi |
| 434 | |
| 435 | .IP "\fBset-session\fP NAME" |
| 436 | .nf |
| 437 | Set current session name |
| 438 | |
| 439 | Will change the session name in the .lttngrc file. |
| 440 | .fi |
| 441 | |
| 442 | .B OPTIONS: |
| 443 | |
| 444 | .nf |
| 445 | \-h, \-\-help |
| 446 | Show summary of possible options and commands. |
| 447 | \-\-list-options |
| 448 | Simple listing of options |
| 449 | .fi |
| 450 | |
| 451 | .IP |
| 452 | |
| 453 | .IP "\fBstart\fP [OPTIONS] [NAME]" |
| 454 | .nf |
| 455 | Start tracing |
| 456 | |
| 457 | It will start tracing for all tracers for a specific tracing session. |
| 458 | |
| 459 | If NAME is omitted, the session name is taken from the .lttngrc file. |
| 460 | .fi |
| 461 | |
| 462 | .B OPTIONS: |
| 463 | |
| 464 | .nf |
| 465 | \-h, \-\-help |
| 466 | Show summary of possible options and commands. |
| 467 | \-\-list-options |
| 468 | Simple listing of options |
| 469 | .fi |
| 470 | |
| 471 | .IP |
| 472 | |
| 473 | .IP "\fBstop\fP [OPTIONS] [NAME]" |
| 474 | .nf |
| 475 | Stop tracing |
| 476 | |
| 477 | It will stop tracing for all tracers for a specific tracing session. |
| 478 | |
| 479 | If NAME is omitted, the session name is taken from the .lttngrc file. |
| 480 | .fi |
| 481 | |
| 482 | .B OPTIONS: |
| 483 | |
| 484 | .nf |
| 485 | \-h, \-\-help |
| 486 | Show summary of possible options and commands. |
| 487 | \-\-list-options |
| 488 | Simple listing of options |
| 489 | .fi |
| 490 | |
| 491 | .IP |
| 492 | |
| 493 | .IP "\fBversion\fP" |
| 494 | .nf |
| 495 | Show version information |
| 496 | .fi |
| 497 | |
| 498 | .B OPTIONS: |
| 499 | |
| 500 | .nf |
| 501 | \-h, \-\-help |
| 502 | Show summary of possible options and commands. |
| 503 | \-\-list-options |
| 504 | Simple listing of options |
| 505 | .fi |
| 506 | |
| 507 | .IP |
| 508 | |
| 509 | .IP "\fBview\fP [SESSION_NAME] [OPTIONS]" |
| 510 | .nf |
| 511 | View traces of a tracing session |
| 512 | |
| 513 | By default, the babeltrace viewer will be used for text viewing. |
| 514 | |
| 515 | If SESSION_NAME is omitted, the session name is taken from the .lttngrc file. |
| 516 | |
| 517 | .fi |
| 518 | |
| 519 | .B OPTIONS: |
| 520 | |
| 521 | .nf |
| 522 | \-h, \-\-help |
| 523 | Show this help |
| 524 | \-\-list-options |
| 525 | Simple listing of options |
| 526 | \-t, \-\-trace-path PATH |
| 527 | Trace directory path for the viewer |
| 528 | \-e, \-\-viewer CMD |
| 529 | Specify viewer and/or options to use |
| 530 | This will completely override the default viewers so |
| 531 | please make sure to specify the full command. The trace |
| 532 | directory path of the session will be appended at the end |
| 533 | to the arguments |
| 534 | .fi |
| 535 | |
| 536 | .SH "EXIT VALUES" |
| 537 | |
| 538 | .IP "0" |
| 539 | Success |
| 540 | |
| 541 | .IP "1" |
| 542 | Command error |
| 543 | |
| 544 | .IP "2" |
| 545 | Undefined command |
| 546 | |
| 547 | .IP "3" |
| 548 | Fatal error |
| 549 | |
| 550 | .IP "4" |
| 551 | Command warning |
| 552 | |
| 553 | .IP "16" |
| 554 | No session found by the name given |
| 555 | |
| 556 | .IP "18" |
| 557 | Error in session creation |
| 558 | |
| 559 | .IP "21" |
| 560 | Error in application(s) listing |
| 561 | |
| 562 | .IP "28" |
| 563 | Session name already exists |
| 564 | |
| 565 | .IP "33" |
| 566 | Kernel tracer unavailable |
| 567 | |
| 568 | .IP "35" |
| 569 | Kernel event exists |
| 570 | |
| 571 | .IP "37" |
| 572 | Kernel channel exists |
| 573 | |
| 574 | .IP "38" |
| 575 | Kernel channel creation failed |
| 576 | |
| 577 | .IP "39" |
| 578 | Kernel channel not found |
| 579 | |
| 580 | .IP "40" |
| 581 | Kernel channel disable failed |
| 582 | |
| 583 | .IP "41" |
| 584 | Kernel channel enable failed |
| 585 | |
| 586 | .IP "42" |
| 587 | Kernel context failed |
| 588 | |
| 589 | .IP "43" |
| 590 | Kernel enable event failed |
| 591 | |
| 592 | .IP "44" |
| 593 | Kernel disable event failed |
| 594 | |
| 595 | .IP "53" |
| 596 | Kernel listing events failed |
| 597 | |
| 598 | .IP "60" |
| 599 | UST channel disable failed |
| 600 | |
| 601 | .IP "61" |
| 602 | UST channel enable failed |
| 603 | |
| 604 | .IP "62" |
| 605 | UST adding context failed |
| 606 | |
| 607 | .IP "63" |
| 608 | UST event enable failed |
| 609 | |
| 610 | .IP "64" |
| 611 | UST event disable failed |
| 612 | |
| 613 | .IP "66" |
| 614 | UST start failed |
| 615 | |
| 616 | .IP "67" |
| 617 | UST stop failed |
| 618 | |
| 619 | .IP "75" |
| 620 | UST event exists |
| 621 | |
| 622 | .IP "76" |
| 623 | UST event not found |
| 624 | |
| 625 | .IP "77" |
| 626 | UST context exists |
| 627 | |
| 628 | .IP "78" |
| 629 | UST invalid context |
| 630 | |
| 631 | .IP "79" |
| 632 | Tracing the kernel requires a root lttng-sessiond daemon and "tracing" group |
| 633 | user membership. |
| 634 | |
| 635 | .IP "80" |
| 636 | Tracing already started |
| 637 | |
| 638 | .IP "81" |
| 639 | Tracing already stopped |
| 640 | .PP |
| 641 | .SH "ENVIRONMENT VARIABLES" |
| 642 | |
| 643 | .PP |
| 644 | Note that all command line options override environment variables. |
| 645 | .PP |
| 646 | |
| 647 | .PP |
| 648 | .IP "LTTNG_SESSIOND_PATH_ENV" |
| 649 | Allows one to specify the full session daemon binary path to lttng command line |
| 650 | tool. You can also use \-\-sessiond-path option having the same effect. |
| 651 | .SH "SEE ALSO" |
| 652 | |
| 653 | .PP |
| 654 | babeltrace(1), lttng-ust(3), lttng-sessiond(8) |
| 655 | .PP |
| 656 | .SH "BUGS" |
| 657 | |
| 658 | .PP |
| 659 | No show stopper bugs are known yet in this version. |
| 660 | |
| 661 | If you encounter any issues or usability problem, please report it on our |
| 662 | mailing list <lttng-dev@lists.lttng.org> to help improve this project. |
| 663 | .SH "CREDITS" |
| 664 | |
| 665 | .PP |
| 666 | lttng is distributed under the GNU General Public License version 2. See the file |
| 667 | COPYING for details. |
| 668 | .PP |
| 669 | A Web site is available at http://lttng.org for more information on the LTTng |
| 670 | project. |
| 671 | .PP |
| 672 | You can also find our git tree at http://git.lttng.org. |
| 673 | .PP |
| 674 | Mailing lists for support and development: <lttng-dev@lists.lttng.org>. |
| 675 | .PP |
| 676 | You can find us on IRC server irc.oftc.net (OFTC) in #lttng. |
| 677 | .PP |
| 678 | .SH "THANKS" |
| 679 | |
| 680 | .PP |
| 681 | Thanks to Yannick Brosseau without whom this project would never have been so |
| 682 | lean and mean! Also thanks to the Ericsson teams working on tracing which |
| 683 | helped us greatly with detailed bug reports and unusual test cases. |
| 684 | |
| 685 | Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA |
| 686 | maintainer) and Jon Bernard for our Debian packages. |
| 687 | |
| 688 | Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de |
| 689 | Montreal for the LTTng journey. |
| 690 | .PP |
| 691 | .SH "AUTHORS" |
| 692 | |
| 693 | .PP |
| 694 | lttng-tools was originally written by Mathieu Desnoyers, Julien Desfossez and |
| 695 | David Goulet. More people have since contributed to it. It is currently |
| 696 | maintained by David Goulet <dgoulet@efficios.com>. |
| 697 | .PP |