X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=doc%2Fman%2Flttng-event-rule.7.txt;fp=doc%2Fman%2Flttng-event-rule.7.txt;h=3fad65c86d1da8bd7b906e28ab7221bc680f5804;hp=b28d23aae4acb97aaac6768e11e4748dbaf43532;hb=26f0c7794376456fcb5b13d4eae91c0ccf0dfe66;hpb=65750bcdda3dd71b72683573d35a662c0b467a8f diff --git a/doc/man/lttng-event-rule.7.txt b/doc/man/lttng-event-rule.7.txt index b28d23aae..3fad65c86 100644 --- a/doc/man/lttng-event-rule.7.txt +++ b/doc/man/lttng-event-rule.7.txt @@ -1,6 +1,6 @@ lttng-event-rule(7) =================== -:revdate: 19 April 2021 +:revdate: 3 May 2021 NAME @@ -14,26 +14,26 @@ Specify an event rule to match Linux kernel tracepoint or system call events: [verse] -option:--domain=kernel option:--type=(tracepoint | syscall[:entry|:exit|:entry+exit])] +option:--domain=**kernel** option:--type=(**tracepoint** | **syscall**[**:entry**|**:exit**|**pass:[:entry+exit]**])] pass:[[]option:--name='NAME'] [option:--filter='EXPR'] Specify an event rule to match Linux kernel kprobe or user space probe events: [verse] -option:--domain=kernel option:--type=(kprobe | uprobe) option:--location='LOC' +option:--domain=**kernel** option:--type=(**kprobe** | **uprobe**) option:--location='LOC' pass:[[]option:--event-name='EVENTNAME'] [option:--filter='EXPR'] Specify an event rule to match user space tracepoint events: [verse] -option:--domain=user [option:--type=tracepoint] [option:--name='NAME'] [option:--exclude-name='XNAME']... +option:--domain=**user** [option:--type=**tracepoint**] [option:--name='NAME'] [option:--exclude-name='XNAME']... pass:[[]option:--log-level=('LOGLEVEL' | 'LOGLEVEL'.. | ..)] [option:--filter='EXPR'] Specify an event rule to match Java/Python logging events: [verse] -option:--domain=(jul | log4j | python) [option:--type=logging] [option:--name='NAME'] +option:--domain=(**jul** | **log4j** | **python**) [option:--type=**logging**] [option:--name='NAME'] pass:[[]option:--log-level=('LOGLEVEL' | 'LOGLEVEL'.. | ..)] [option:--filter='EXPR'] @@ -46,6 +46,9 @@ As of LTTng{nbsp}{lttng_version}, the command-line options documented here only apply to the `event-rule-matches` trigger condition specifier (see man:lttng-add-trigger(1)). +See man:lttng-concepts(7) to learn more about instrumentation points, +events, and event rules. + [NOTE] ==== This manual page only describes the common event rule options. The @@ -58,57 +61,8 @@ condition. ==== -Core concepts -~~~~~~~~~~~~~ -An _instrumentation point_ is a point, within a piece of software, -which, when executed, creates an LTTng _event_. - -LTTng offers various types of instrumentation; see the -<> section -below to learn about them. - -An _event rule_ is a set of conditions to match a set of events. - -When LTTng creates an event{nbsp}__E__, a event rule{nbsp}__ER__ is said -to __match__{nbsp}__E__ when{nbsp}__E__ satisfies *all* the conditions -of{nbsp}__ER__. This concept is similar to a regular expression which -matches a set of strings. - -When an event rule matches an event, LTTng _emits_ the event, -therefore attempting to execute one or more actions. - -[NOTE] -==== -The event creation and emission processes are documentation concepts to -help understand the journey from an instrumentation point to the -execution of actions. - -The actual creation of an event can be costly because LTTng needs to -evalute the arguments of the instrumentation point. - -In practice, LTTng implements various optimizations for the Linux kernel -and user space tracing domains (option:--domain=++kernel++ and -option:--domain=++user++ options) to avoid actually creating an event -when the tracer knows, thanks to properties which are independent from -the event payload and current context, that it would never emit such an -event. Those properties are: - -* The instrumentation point type (see the - <> section below). -* The instrumentation point name (or event name) - (see the <> section below). -* The instrumentation point log level (see the - <> - section below). - -In other words: if, for a given instrumentation point{nbsp}__IP__, the -LTTng tracer knows that it would never emit an event, -executing{nbsp}__IP__ represents a simple boolean variable check. -==== - - -Event rule overview -~~~~~~~~~~~~~~~~~~~ +Overview of event rule condtions +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For LTTng to emit an event{nbsp}__E__,{nbsp}__E__ must satisfy *all* the conditions of an event rule, that is: @@ -802,7 +756,12 @@ option:-f 'EXPR', option:--filter='EXPR':: event payload and current context fields, is _true_. +include::common-footer.txt[] + + SEE ALSO -------- man:lttng(1), -man:lttng-add-trigger(1) +man:lttng-add-trigger(1), +man:lttng-concepts(7), +man:lttng-list(1)