8 lttng-enable-event - Create or enable LTTng recording event rules
13 Create or enable one or more recording event rules to match Linux kernel
14 tracepoint or system call events:
17 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event* option:--kernel [option:--tracepoint | option:--syscall]
18 (option:--all | 'NAME'[,'NAME']...) [option:--filter='EXPR']
19 [option:--session='SESSION'] [option:--channel='CHANNEL']
21 Create or enable a recording event rule to match Linux kernel events
22 created from a dynamic instrumentation point:
25 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event* option:--kernel
26 (option:--probe='LOC' | option:--function='LOC' | option:--userspace-probe='LOC') 'RECORDNAME'
27 [option:--filter='EXPR'] [option:--session='SESSION'] [option:--channel='CHANNEL']
29 Create or enable one or more recording event rules to match
30 user space tracepoint events:
33 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event* option:--userspace [option:--tracepoint]
34 (option:--all | 'NAME'[,'NAME']...) [option:--exclude='XNAME'[,'XNAME']...]
35 [option:--loglevel='LOGLEVEL' | option:--loglevel-only='LOGLEVEL'] [option:--filter='EXPR']
36 [option:--session='SESSION'] [option:--channel='CHANNEL']
38 Create or enable one or more recording event rules to match
39 Java/Python logging events:
42 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event* (option:--jul | option:--log4j | option:--python)
43 [option:--tracepoint] (option:--all | 'NAME'[,'NAME']...)
44 [option:--loglevel='LOGLEVEL' | option:--loglevel-only='LOGLEVEL'] [option:--filter='EXPR']
45 [option:--session='SESSION'] [option:--channel='CHANNEL']
49 The `lttng enable-event` command does one of:
51 * Create one or more recording event rules.
53 * Enable one or more disabled recording event rules.
55 See the <<enable,Enable a disabled recording event rule>> section
58 See man:lttng-concepts(7) to learn more about instrumentation points,
59 events, recording event rules, and event records.
61 The recording event rule(s) to create or enable belong to:
63 With the option:--session='SESSION' option::
64 The tracing session named 'SESSION'.
66 Without the option:--session option::
67 The current tracing session (see man:lttng-concepts(7) to learn more
68 about the current tracing session).
70 With the option:--channel='CHANNEL' option::
71 The channel named 'CHANNEL'.
73 Without the option:--channel option::
74 The channel named `channel0`.
76 If such a channel doesn't exist, the `enable-event` automatically
79 List the recording event rules of a specific tracing session
80 and/or channel with the man:lttng-list(1) and man:lttng-status(1)
83 Disable an enabled recording event rule with the
84 man:lttng-disable-event(1) command.
87 Overview of recording event rule conditions
88 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
89 For LTTng to emit and record an event{nbsp}__E__,{nbsp}__E__ must
90 satisfy *all* the conditions of a recording event rule{nbsp}__ER__, that
94 You set the following conditions when you create or
95 enable{nbsp}__ER__ with the `enable-event` command:
98 * The instrumentation point type from which LTTng creates{nbsp}__E__
101 See the <<inst-point-type-cond,Instrumentation point type condition>>
104 * A pattern matches the name of{nbsp}__E__ while another pattern
107 See the <<event-name-cond,Event name condition>> section below.
109 * The log level of the instrumentation point from which LTTng
110 creates{nbsp}__E__ is at least as severe as some value, or is exactly
113 See the <<inst-point-log-level-cond,Instrumentation point log level condition>>
116 * The fields of the payload of{nbsp}__E__ and the current context fields
117 satisfy a filter expression.
119 See the <<filter-cond,Event payload and context filter condition>>
123 Implicit conditions::
126 * _ER_ itself is enabled.
128 A recording event rule is enabled on creation.
130 Enable a disabled recording event rule with the `enable-event` command.
132 * The channel to which{nbsp}__ER__ is attached is enabled.
134 A channel is enabled on creation.
136 Enable a disabled channel with the man:lttng-enable-channel(1) command.
138 * The tracing session of{nbsp}__ER__ is active (started).
140 A tracing session is inactive (stopped) on creation.
142 Start an inactive tracing session with the man:lttng-start(1) command.
144 * The process for which LTTng creates{nbsp}__E__ is allowed to record
147 All processes are allowed to record events on tracing session
150 Use the man:lttng-track(1) and man:lttng-untrack(1) commands to select
151 which processes are allowed to record events based on specific process
155 The dedicated command-line options of most conditions are optional: if
156 you don't specify the option, the associated condition is always
160 [[inst-point-type-cond]]
161 Instrumentation point type condition
162 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
163 An event{nbsp}__E__ satisfies the instrumentation point type condition
164 of a recording event rule if the instrumentation point from which LTTng
165 creates{nbsp}__E__ is:
167 For the Linux kernel tracing domain (option:--kernel option)::
168 With the option:--tracepoint option or without any other instrumentation point type option:::
169 An LTTng kernel tracepoint, that is, a statically defined point
170 in the source code of the kernel image or of a kernel module
171 with LTTng kernel tracer macros.
173 As of LTTng{nbsp}{lttng_version}, this is the default instrumentation
174 point type of the Linux kernel tracing domain, but this may change in
177 List the available Linux kernel tracepoints with `lttng list --kernel`.
178 See man:lttng-list(1) to learn more.
180 With the option:--syscall option:::
181 The entry and exit of a Linux kernel system call.
183 List the available Linux kernel system call instrumentation points with
184 `lttng list --kernel --syscall`. See man:lttng-list(1) to learn more.
186 With the option:--probe option:::
187 A Linux kprobe, that is, a single probe dynamically placed in
188 the compiled kernel code.
190 The argument of the option:--probe option is the location of the
191 kprobe to insert, either a symbol or a
192 memory address, while 'RECORDNAME' is the name of the record
193 of{nbsp}__E__ (see the <<er-name,Event record name>> section below).
195 The payload of a Linux kprobe event is empty.
197 With the option:--userspace-probe option:::
198 A Linux user space probe, that is, a single probe dynamically
199 placed at the entry of a compiled user space application/library
200 function through the kernel.
202 The argument of the option:--userspace-probe option is the location
203 of the user space probe to insert, one of:
206 * A path and symbol (ELF method).
207 * A path, provider name, and probe name (SystemTap User-level Statically
208 Defined Tracing (USDT) method; a DTrace-style marker).
210 As of LTTng{nbsp}{lttng_version}, LTTng only supports USDT probes which
211 are :not: reference-counted.
214 'RECORDNAME' is the name of the record of{nbsp}__E__ (see the
215 <<er-name,Event record name>> section below).
217 The payload of a Linux user space probe event is empty.
219 With the option:--function option:::
220 A Linux kretprobe, that is, two probes dynamically placed at the
221 entry and exit of a function in the compiled kernel code.
223 The argument of the option:--function option is the location of the
224 Linux kretprobe to insert, either a symbol or
225 a memory address, while 'RECORDNAME' is the name of the record
226 of{nbsp}__E__ (see the <<er-name,Event record name>> section below).
228 The payload of a Linux kretprobe event is empty.
230 For the user space tracing domain (option:--userspace option)::
231 With or without the option:--tracepoint option:::
232 An LTTng user space tracepoint, that is, a statically defined
233 point in the source code of a C/$$C++$$ application/library with
234 LTTng user space tracer macros.
236 As of LTTng{nbsp}{lttng_version}, this is the default and sole
237 instrumentation point type of the user space tracing domain, but this
238 may change in the future.
240 List the available user space tracepoints with `lttng list --userspace`.
241 See man:lttng-list(1) to learn more.
243 For the `java.util.logging` (option:--jul option), Apache log4j (option:--log4j option), and Python (option:--python option) tracing domains::
244 With or without the option:--tracepoint option:::
247 As of LTTng{nbsp}{lttng_version}, this is the default and sole
248 instrumentation point type of the `java.util.logging`, Apache log4j, and
249 Python tracing domains, but this may change in the future.
251 List the available Java and Python loggers with `lttng list --jul`,
252 `lttng list --log4j`, and `lttng list --python`. See man:lttng-list(1)
259 An event{nbsp}__E__ satisfies the event name condition of a recording
260 event rule{nbsp}__ER__ if the two following statements are true:
262 * You specify the option:--all option or, depending on the
263 instrumentation type condition (see the
264 <<inst-point-type-cond,Instrumentation point type condition>> section
265 above) of{nbsp}__ER__, 'NAME' matches:
269 The full name of the tracepoint from which LTTng creates{nbsp}__E__.
271 Note that the full name of a user space tracepoint is
272 __PROVIDER__++:++__NAME__, where __PROVIDER__ is the tracepoint provider
273 name and __NAME__ is the tracepoint name.
276 The name of the Java or Python logger from which LTTng
280 The name of the system call, without any `sys_` prefix, from which
281 LTTng creates{nbsp}__E__.
284 * You don't specify the option:--exclude=__XNAME__[++,++__XNAME__]...
285 option or, depending on the instrumentation type condition
286 of{nbsp}__ER__, none of the 'XNAME' arguments matches the full name of
287 the user space tracepoint from which LTTng creates{nbsp}__E__.
289 The option:--exclude option is only available with the option:--userspace
292 This condition is only meaningful for the LTTng tracepoint, logging
293 statement, and Linux system call instrumentation point types: it's
294 always satisfied for the other types.
296 In all cases, 'NAME' and 'XNAME' are globbing patterns: the `*`
297 character means ``match anything''. To match a literal `*` character,
298 use :escwc:. To match a literal `,` character, use
301 IMPORTANT: Make sure to **single-quote** 'NAME' and 'XNAME' when they
302 contain the `*` character and when you run the `enable-event` command
305 With the LTTng tracepoint, logging statement, and Linux system call
306 instrumentation point types, the `enable-event` command creates or
307 enables one independent recording event rule per 'NAME' argument
308 (non-option, comma-separated). With the option:--all option, the
309 `enable-event` command creates or enables a single recording event rule.
312 [[inst-point-log-level-cond]]
313 Instrumentation point log level condition
314 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
315 An event{nbsp}__E__ satisfies the instrumentation point log level
316 condition of a recording event rule if either:
318 * The option:--loglevel and option:--loglevel-only options are
321 * The log level of the LTTng user space tracepoint or logging statement
322 which creates{nbsp}__E__ is:
323 With the option:--loglevel='LOGLEVEL' option::
324 At least as severe as 'LOGLEVEL'.
326 With the option:--loglevel-only='LOGLEVEL' option::
329 This condition is only meaningful for the LTTng user space tracepoint
330 and logging statement instrumentation point types: it's always satisfied
333 The available values of 'LOGLEVEL' are, depending on the tracing domain,
334 from the most to the least severe:
336 User space (option:--userspace option)::
337 Shortcuts such as `system` are allowed.
343 * `TRACE_WARNING` (4)
346 * `TRACE_DEBUG_SYSTEM` (7)
347 * `TRACE_DEBUG_PROGRAM` (8)
348 * `TRACE_DEBUG_PROCESS` (9)
349 * `TRACE_DEBUG_MODULE` (10)
350 * `TRACE_DEBUG_UNIT` (11)
351 * `TRACE_DEBUG_FUNCTION` (12)
352 * `TRACE_DEBUG_LINE` (13)
355 `java.util.logging` (option:--jul option)::
356 Shortcuts such as `severe` are allowed.
358 * `JUL_OFF` (`INT32_MAX`)
359 * `JUL_SEVERE` (1000)
360 * `JUL_WARNING` (900)
366 * `JUL_ALL` (`INT32_MIN`)
368 Apache log4j (option:--log4j option)::
369 Shortcuts such as `severe` are allowed.
371 * `LOG4J_OFF` (`INT32_MAX`)
372 * `LOG4J_FATAL` (50000)
373 * `LOG4J_ERROR` (40000)
374 * `LOG4J_WARN` (30000)
375 * `LOG4J_INFO` (20000)
376 * `LOG4J_DEBUG` (10000)
377 * `LOG4J_TRACE` (5000)
378 * `LOG4J_ALL` (`INT32_MIN`)
380 Python (option:--python option)::
381 Shortcuts such as `critical` are allowed.
383 * `PYTHON_CRITICAL` (50)
384 * `PYTHON_ERROR` (40)
385 * `PYTHON_WARNING` (30)
387 * `PYTHON_DEBUG` (10)
388 * `PYTHON_NOTSET` (0)
392 Event payload and context filter condition
393 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
394 An event{nbsp}__E__ satisfies the event payload and context filter
395 condition of a recording event rule if the option:--filter='EXPR'
396 option is missing or if 'EXPR' is _true_.
398 'EXPR' can contain references to the payload fields of{nbsp}__E__ and
399 to the current context fields.
401 IMPORTANT: Make sure to **single-quote** 'EXPR' when you run the
402 `enable-event` command from a shell, as filter expressions typically
403 include characters having a special meaning for most shells.
405 The expected syntax of 'EXPR' is similar to the syntax of a
406 C{nbsp}language conditional expression (an expression which an `if`
407 statement can evaluate), but there are a few differences:
409 * A _NAME_ expression identifies an event payload field named
410 _NAME_ (a C{nbsp}identifier).
412 Use the C{nbsp}language dot and square bracket notations to access
413 nested structure and array/sequence fields. You can only use a constant,
414 positive integer number within square brackets. If the index is out of
415 bounds, 'EXPR' is _false_.
417 The value of an enumeration field is an integer.
419 When a field expression doesn't exist, 'EXPR' is _false_.
421 Examples: `my_field`, `target_cpu`, `seq[7]`, `msg.user[1].data[2][17]`.
423 * A ++$ctx.++__TYPE__ expression identifies the statically-known context
424 field having the type _TYPE_ (a C{nbsp}identifier).
426 List the available statically-known context field names with the
427 man:lttng-add-context(1) command.
429 When a field expression doesn't exist, 'EXPR' is _false_.
431 Examples: `$ctx.prio`, `$ctx.preemptible`,
432 `$ctx.perf:cpu:stalled-cycles-frontend`.
434 * A ++$app.++__PROVIDER__++:++__TYPE__ expression identifies the
435 application-specific context field having the type _TYPE_ (a
436 C{nbsp}identifier) from the provider _PROVIDER_ (a C{nbsp}identifier).
438 When a field expression doesn't exist, 'EXPR' is _false_.
440 Example: `$app.server:cur_user`.
442 * Compare strings, either string fields or string literals
443 (double-quoted), with the `==` and `!=` operators.
445 When comparing to a string literal, the `*` character means ``match
446 anything''. To match a literal `*` character, use :escwc:.
448 Examples: `my_field == "user34"`, `my_field == my_other_field`,
449 `my_field == "192.168.*"`.
451 * The precedence table of the operators which are supported in 'EXPR'
452 is as follows. In this table, the highest precedence is{nbsp}1:
456 |Precedence |Operator |Description |Associativity
457 |1 |`-` |Unary minus |Right-to-left
458 |1 |`+` |Unary plus |Right-to-left
459 |1 |`!` |Logical NOT |Right-to-left
460 |1 |`~` |Bitwise NOT |Right-to-left
461 |2 |`<<` |Bitwise left shift |Left-to-right
462 |2 |`>>` |Bitwise right shift |Left-to-right
463 |3 |`&` |Bitwise AND |Left-to-right
464 |4 |`^` |Bitwise XOR |Left-to-right
465 |5 |`\|` |Bitwise OR |Left-to-right
466 |6 |`<` |Less than |Left-to-right
467 |6 |`<=` |Less than or equal to |Left-to-right
468 |6 |`>` |Greater than |Left-to-right
469 |6 |`>=` |Greater than or equal to |Left-to-right
470 |7 |`==` |Equal to |Left-to-right
471 |7 |`!=` |Not equal to |Left-to-right
472 |8 |`&&` |Logical AND |Left-to-right
473 |9 |`\|\|` |Logical OR |Left-to-right
476 Parentheses are supported to bypass the default order.
478 IMPORTANT: Unlike the C{nbsp}language, the bitwise AND and OR operators
479 (`&` and `|`) in 'EXPR' take precedence over relational operators (`<`,
480 `<=`, `>`, `>=`, `==`, and `!=`). This means the expression `2 & 2 == 2`
481 is _true_ while the equivalent C{nbsp}expression is _false_.
483 The arithmetic operators are :not: supported.
485 LTTng first casts all integer constants and fields to signed 64-bit
486 integers. The representation of negative integers is two's complement.
487 This means that, for example, the signed 8-bit integer field 0xff (-1)
488 becomes 0xffffffffffffffff (still -1) once casted.
490 Before a bitwise operator is applied, LTTng casts all its operands to
491 unsigned 64-bit integers, and then casts the result back to a signed
492 64-bit integer. For the bitwise NOT operator, it's the equivalent of
493 this C{nbsp}expression:
497 (int64_t) ~((uint64_t) val)
500 For the binary bitwise operators, it's the equivalent of those
505 (int64_t) ((uint64_t) lhs >> (uint64_t) rhs)
506 (int64_t) ((uint64_t) lhs << (uint64_t) rhs)
507 (int64_t) ((uint64_t) lhs & (uint64_t) rhs)
508 (int64_t) ((uint64_t) lhs ^ (uint64_t) rhs)
509 (int64_t) ((uint64_t) lhs | (uint64_t) rhs)
512 If the right-hand side of a bitwise shift operator (`<<` and `>>`) is
513 not in the [0,{nbsp}63] range, then 'EXPR' is _false_.
517 Use the man:lttng-track(1) and man:lttng-untrack(1) commands to allow or
518 disallow processes to record LTTng events based on their attributes
519 instead of using equivalent statically-known context fields in 'EXPR'
522 The former method is much more efficient.
527 ----------------------------
528 msg_id == 23 && size >= 2048
529 ----------------------------
531 -------------------------------------------------
532 $ctx.procname == "lttng*" && (!flag || poel < 34)
533 -------------------------------------------------
535 ---------------------------------------------------------
536 $app.my_provider:my_context == 17.34e9 || some_enum >= 14
537 ---------------------------------------------------------
539 ---------------------------------------
540 $ctx.cpu_id == 2 && filename != "*.log"
541 ---------------------------------------
543 ------------------------------------------------
544 eax_reg & 0xff7 == 0x240 && x[4] >> 12 <= 0x1234
545 ------------------------------------------------
551 When LTTng records an event{nbsp}__E__, the resulting event record has a
552 name which depends on the instrumentation point type condition (see the
553 <<inst-point-type-cond,Instrumentation point type condition>> section
554 above) of the recording event rule which matched{nbsp}__E__:
556 LTTng tracepoint (option:--kernel/option:--userspace and option:--tracepoint options)::
557 Full name of the tracepoint from which LTTng creates{nbsp}__E__.
559 Note that the full name of a user space tracepoint is
560 __PROVIDER__++:++__NAME__, where __PROVIDER__ is the tracepoint provider
561 name and __NAME__ is the tracepoint name.
563 `java.util.logging` logging statement (option:--jul and option:--tracepoint options)::
566 Such an event record has a string field `logger_name` which contains the
567 name of the `java.util.logging` logger from which LTTng
570 Apache log4j logging statement (option:--log4j and option:--tracepoint options)::
573 Such an event record has a string field `logger_name` which contains the
574 name of the Apache log4j logger from which LTTng creates{nbsp}__E__.
576 Python logging statement (option:--python and option:--tracepoint options)::
579 Such an event record has a string field `logger_name` which contains the
580 name of the Python logger from which LTTng creates{nbsp}__E__.
582 Linux system call (option:--kernel and option:--syscall options)::
584 ++syscall_entry_++__NAME__, where _NAME_ is the name of the
585 system call from which LTTng creates{nbsp}__E__, without any
589 ++syscall_exit_++__NAME__, where _NAME_ is the name of the
590 system call from which LTTng creates{nbsp}__E__, without any
593 Linux kprobe (option:--kernel and option:--probe options)::
594 Linux user space probe (option:--kernel and option:--userspace-probe options)::
595 'RECORDNAME' (first non-option argument).
597 Linux kretprobe (option:--kernel and option:--function options)::
599 __RECORDNAME__++_entry++
602 __RECORDNAME__++_exit++
606 Enable a disabled recording event rule
607 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
608 The `enable-event` command can enable a disabled recording event rule,
609 as listed in the output of the man:lttng-list(1) command.
611 You may enable a disabled recording event rule regardless of the
612 activity (started or stopped) of its tracing session (see
613 man:lttng-start(1) and man:lttng-stop(1)).
615 To enable a disabled recording event rule, run the `enable-event`
616 command with the exact same options and arguments that you used to
617 create it. In particular, with the option:--filter='EXPR' option, 'EXPR'
618 must be the exact same string as the one you used on creation.
621 include::common-lttng-cmd-options-head.txt[]
628 option:-j, option:--jul::
629 Create or enable recording event rules in the `java.util.logging`
630 (JUL) tracing domain.
632 option:-k, option:--kernel::
633 Create or enable recording event rules in the Linux kernel tracing
636 option:-l, option:--log4j::
637 Create or enable recording event rules in the Apache log4j tracing
640 option:-p, option:--python::
641 Create or enable recording event rules in the Python tracing domain.
643 option:-u, option:--userspace::
644 Create or enable recording event rules in the user space tracing
650 option:-c 'CHANNEL', option:--channel='CHANNEL'::
651 Create or enable recording event rules attached to the channel named
652 'CHANNEL' instead of `channel0`.
654 option:-s 'SESSION', option:--session='SESSION'::
655 Create or enable recording event rules in the tracing session named
656 'SESSION' instead of the current tracing session.
659 Instrumentation point type condition
660 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
661 See the <<inst-point-type-cond,Instrumentation point type condition>>
666 option:--function='LOC'::
667 Only match Linux kretprobe events.
669 Only available with the option:--kernel option.
674 * A function address (`0x` hexadecimal prefix supported).
675 * A function symbol name.
676 * A function symbol name and an offset
677 (__SYMBOL__++pass:[+]++__OFFSET__ format).
680 You must specify the event record name with 'RECORDNAME'. See the
681 <<er-name,Event record name>> section above to learn more.
683 option:--probe='LOC'::
684 Only match Linux kprobe events.
686 Only available with the option:--kernel option.
691 * An address (`0x` hexadecimal prefix supported).
693 * A symbol name and an offset (__SYMBOL__++pass:[+]++__OFFSET__ format).
696 You must specify the event record name with 'RECORDNAME'. See the
697 <<er-name,Event record name>> section above to learn more.
699 option:--userspace-probe='LOC'::
700 Only match Linux user space probe events.
702 Only available with the option:--kernel option.
707 \[++elf:++]__PATH__++:++__SYMBOL__::
708 Probe an available symbol within a user space application or
713 Application or library path.
719 * The name of an application as found in the directories listed in the
720 `PATH` environment variable.
723 Symbol name of the function of which to instrument the entry.
725 'SYMBOL' can be any defined code symbol in the output of the man:nm(1)
726 command, including with its nloption:--dynamic option, which lists
730 As of LTTng{nbsp}{lttng_version}, not specifying `elf:` is equivalent to
731 specifying it, but this default may change in the future.
735 * `--userspace-probe=/usr/lib/libc.so.6:malloc`
736 * `--userspace-probe=./myapp:createUser`
737 * `--userspace-probe=elf:httpd:ap_run_open_htaccess`
739 ++sdt:++__PATH__++:++__PROVIDER__++:++__NAME__::
740 Use a SystemTap User-level Statically Defined Tracing (USDT) probe
741 within a user space application or library.
745 Application or library path.
751 * The name of an application as found in the directories listed in the
752 `PATH` environment variable.
756 USDT provider and probe names.
758 For example, with the following USDT probe:
762 DTRACE_PROBE2("server", "accept_request",
763 request_id, ip_addr);
766 The provider/probe name pair is `server:accept_request`.
769 Example: `--userspace-probe=sdt:./build/server:server:accept_request`
772 You must specify the event record name with 'RECORDNAME'. See the
773 <<er-name,Event record name>> section above to learn more.
776 Only match Linux system call events.
778 Only available with the option:--kernel option.
780 option:--tracepoint::
783 With the option:--kernel or option:--userspace option:::
784 LTTng tracepoint events.
785 With the option:--jul, option:--log4j, or option:--python option:::
788 With the option:--kernel, not specifying any of the instrumentation
789 point type options is equivalent to specifying the option:--tracepoint
790 option, but this default may change in the future.
792 With the option:--userspace, option:--jul, option:--log4j, and
793 option:--python options, not specifying the option:--tracepoint option
794 is equivalent to specifying it, but this default may change in the
800 See the <<event-name-cond,Event name condition>> section above.
802 option:-a, option:--all::
803 Equivalent to a single 'NAME' argument (LTTng tracepoint or logger
804 name) set to `*` (match anything).
806 You may :not: use this option with a 'NAME' argument.
808 option:-x 'XNAME'[,'XNAME']..., option:--exclude='XNAME'[,'XNAME']...::
809 Only match events of which none of the 'XNAME' arguments
810 matches the full name of the LTTng user space tracepoint.
812 Only available with the option:--userspace option.
814 'XNAME' is a globbing pattern: the `*` character means ``match
815 anything''. To match a literal `*` character, use :escwc:. To match
816 a literal `,` character, use :esccomma:.
819 Instrumentation point log level condition
820 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
821 See the <<inst-point-log-level-cond,Instrumentation point log level
822 condition>> section above.
826 option:--loglevel='LOGLEVEL'::
827 Only match events of which the log level of the LTTng tracepoint or
828 logging statement is at least as severe as 'LOGLEVEL'.
830 option:--loglevel-only='LOGLEVEL'::
831 Only match events of which the log level of the LTTng tracepoint or
832 logging statement is exactly 'LOGLEVEL'.
834 The instrumentation point log level options above are :not: available
835 with the option:--kernel option.
838 Event payload and context filter condition
839 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
840 See the <<filter-cond,Event payload and context filter condition>>
843 option:-f 'EXPR', option:--filter='EXPR'::
844 Only match events of which 'EXPR', which can contain references to
845 event payload and current context fields, is _true_.
848 include::common-lttng-cmd-help-options.txt[]
851 include::common-lttng-cmd-after-options.txt[]
854 include::common-footer.txt[]
860 man:lttng-disable-event(1),
861 man:lttng-enable-channel(1),
865 man:lttng-concepts(7)