lttng-untrack — Remove one or more entries from an LTTng resource tracker
lttng untrack commands removes one or more entries from a
See lttng-track(1) to learn more about LTTng trackers.
The untrack command removes specific resources from a tracker. The
resources to remove must have been precedently added by
lttng-track(1). It is also possible to remove all the
resources from the whitelist using the
As of this version, the only available tracker is the PID tracker.
One common operation is to create a tracing session (see lttng-create(1)), remove all the entries from the PID tracker whitelist, start tracing, and then manually track PIDs while tracing is active.
Assume the maximum system PID is 7 for this example.
       
lttng untrack --userspace --pid --all
[ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ]
$ $ $ $
lttng enable-event --userspace ... lttng start # ... lttng track --userspace --pid=3,5
[ ] [ ] [ ]  [ ]  [ ] [ ]
lttng track --userspace --pid=2
[ ] [ ]   [ ]  [ ] [ ]
Set to 1 to abort the process after the first error is encountered.
$HOME environment variable. Useful when the user
running the commands has a non-writable home directory.
Absolute path to the man pager to use for viewing help information
about LTTng commands (using lttng-help(1) or
lttng COMMAND --help).
Path in which the
session.xsd session configuration XML
schema may be found.
Full session daemon binary path.
--sessiond-path option has precedence over this
Note that the lttng-create(1) command can spawn an LTTng session daemon automatically if none is running. See lttng-sessiond(8) for the environment variables influencing the execution of the session daemon.
User LTTng runtime configuration.
This is where the per-user current tracing session is stored between executions of lttng(1). The current tracing session can be set with lttng-set-session(1). See lttng-create(1) for more information about tracing sessions.
Default output directory of LTTng traces. This can be overridden
--output option of the lttng-create(1)
User LTTng runtime and configuration directory.
$LTTNG_HOME defaults to
$HOME when not explicitly set.
Command warning (something went wrong during the command)
If you encounter any issue or usability problem, please report it on the LTTng bug tracker.
Special thanks to Michel Dagenais and the DORSAL laboratory at École Polytechnique de Montréal for the LTTng journey.
Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases.