X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Flttng-enable-channel.1.txt;h=58aecc10270cfd5e9c5320ec5b927e217888dca0;hb=8f141dbdf7c4628c13d7b099240a7bd4bcacf2cf;hp=271ada1ceb3b0bebb3407b039bda57f7fbc9e8ec;hpb=26f0c7794376456fcb5b13d4eae91c0ccf0dfe66;p=lttng-tools.git diff --git a/doc/man/lttng-enable-channel.1.txt b/doc/man/lttng-enable-channel.1.txt index 271ada1ce..58aecc102 100644 --- a/doc/man/lttng-enable-channel.1.txt +++ b/doc/man/lttng-enable-channel.1.txt @@ -1,6 +1,6 @@ lttng-enable-channel(1) ======================= -:revdate: 3 May 2021 +:revdate: 14 June 2021 NAME @@ -54,16 +54,18 @@ See man:lttng-concepts(7) to learn more about channels. The channel(s) to create or enable belong to: With the option:--session='SESSION' option:: - The tracing session named 'SESSION'. + The recording session named 'SESSION'. Without the option:--session option:: - The current tracing session (see man:lttng-concepts(7) to learn more - about the current tracing session). + The current recording session (see man:lttng-concepts(7) to learn + more about the current recording session). NOTE: The man:lttng-enable-event(1) command can automatically create a default channel when no channel exists for the provided tracing domain. -List the channels of a given tracing session with the +See the ``<>'' section below for usage examples. + +List the channels of a given recording session with the man:lttng-list(1) and man:lttng-status(1) commands. Disable an enabled channel with the man:lttng-disable-channel(1) @@ -76,20 +78,20 @@ operations with the `enable-channel` command: * Change an attribute of an existing channel. -* Enable a disabled channel once its tracing session has been active +* Enable a disabled channel once its recording session has been active (started; see man:lttng-start(1)) at least once. -* Create a channel once its tracing session has been active at least +* Create a channel once its recording session has been active at least once. * Create a user space channel with a given buffering scheme (option:--buffers-uid or option:--buffers-pid options) and create a second user space channel with a different buffering scheme in the - same tracing session. + same recording session. ==== -include::common-cmd-options-head.txt[] +include::common-lttng-cmd-options-head.txt[] Tracing domain @@ -106,8 +108,8 @@ option:-u, option:--userspace:: Recording target ~~~~~~~~~~~~~~~~ option:-s 'SESSION', option:--session='SESSION':: - Create or enable channels in the tracing session named 'SESSION' - instead of the current tracing session. + Create or enable channels in the recording session named 'SESSION' + instead of the current recording session. Buffering scheme @@ -345,15 +347,76 @@ option:--kernel and option:--buffers-global options::: +{default_metadata_switch_timer}+ -include::common-cmd-help-options.txt[] +include::common-lttng-cmd-help-options.txt[] + + +include::common-lttng-cmd-after-options.txt[] + + +[[examples]] +EXAMPLES +-------- +.Create a Linux kernel channel with default attributes in the current recording session. +==== +The following command line only creates a new channel if `my-channel` +doesn't name an existing Linux kernel channel in the current recording +session. + +[role="term"] +---- +$ lttng enable-channel --kernel my-channel +---- +==== + +.Create a user space channel with a per-process buffering scheme in a specific recording session. +==== +See the option:--session and option:--buffers-pid options. + +[role="term"] +---- +$ lttng enable-channel --session=my-session --userspace \ + --buffers-pid my-channel +---- +==== + +.Create a Linux kernel channel in the current recording session with four 32-MiB sub-buffers per ring buffer. +==== +See the option:--num-subbuf and option:--subbuf-size options. + +[role="term"] +---- +$ lttng enable-channel --kernel my-channel \ + --num-subbuf=4 --subbuf-size=32M +---- +==== + +.Create a user space channel in the current recording session with trace file rotation. +==== +See the option:--tracefile-count and option:--tracefile-size options. + +[role="term"] +---- +$ lttng enable-channel --userspace my-channel \ + --tracefile-count=16 --tracefile-size=8M +---- +==== + +.Enable two user space channels of a specific recording session. +==== +[role="term"] +---- +$ lttng enable-channel --session=my-session --userspace \ + canal-d,rds +---- +==== -include::common-cmd-footer.txt[] +include::common-footer.txt[] SEE ALSO -------- man:lttng(1), -man:lttng-concepts(7), man:lttng-disable-channel(1), -man:lttng-list(1) +man:lttng-list(1), +man:lttng-concepts(7)