From 1e85dcc6ee1431ee48a78114c6238c2a86dacad7 Mon Sep 17 00:00:00 2001 From: Philippe Proulx Date: Thu, 7 Sep 2017 22:52:48 -0400 Subject: [PATCH] lttng-enable-event(1): filtering: specify that `$ctx.cpu_id` is available MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Philippe Proulx Signed-off-by: Jérémie Galarneau --- doc/man/lttng-enable-event.1.txt | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/doc/man/lttng-enable-event.1.txt b/doc/man/lttng-enable-event.1.txt index 1a80fe774..497697c91 100644 --- a/doc/man/lttng-enable-event.1.txt +++ b/doc/man/lttng-enable-event.1.txt @@ -176,10 +176,10 @@ argument named `*` (wildcard). [[filter-syntax]] Filter expression syntax ~~~~~~~~~~~~~~~~~~~~~~~~ -Filter expressions can be specified with the option:--filter option -when creating a new event rule. If the filter expression evaluates -to true when executed against the dynamic values of an event's fields -when tracing, the filtering condition passes. +A filter expression can be specified with the option:--filter option +when creating a new event rule. If the filter expression evaluates to +true when executed against the dynamic values of an event's fields when +tracing, the filtering condition passes. NOTE: Make sure to **single-quote** the filter expression when running the command from a shell, as filter expressions typically include @@ -216,13 +216,14 @@ The arithmetic and bitwise operators are :not: supported. The precedence table of the operators above is the same as the one of the C language. Parentheses are supported to bypass this. -The dynamic value of an event field is read by using its name as -a C identifier. +The dynamic value of an event field is read by using its name as a C +identifier. The dynamic value of a statically-known context field is read by prefixing its name with `$ctx.`. Statically-known context fields are context fields added to channels without the `$app.` prefix using the -man:lttng-add-context(1) command. +man:lttng-add-context(1) command. `$ctx.cpu_id` is also available as the +ID of the CPU which emits the event. The dynamic value of an application-specific context field is read by prefixing its name with `$app.` (follows the format used to add such a -- 2.34.1