lttng-untrack(1)
================
:revdate: 14 March 2017


NAME
----
lttng-untrack - Remove one or more entries from an LTTng resource tracker


SYNOPSIS
--------
[verse]
*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *untrack* (option:--kernel | option:--userspace)
      [option:--session='SESSION'] (option:--pid='PID'[,'PID']... | option:--all option:--pid)


DESCRIPTION
-----------
The `lttng untrack` commands removes one or more entries from a
resource tracker.

See man: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
man:lttng-track(1). It is also possible to remove all the
resources from the whitelist using the option:--all option.

As of this version, the only available tracker is the PID tracker.


Example
~~~~~~~
One common operation is to create a tracing session
(see man: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.

Command:

[role="term"]
----
$ lttng create
----

Initial whitelist:

-------------------------------
[0] [1] [2] [3] [4] [5] [6] [7]
-------------------------------

Command:

[role="term"]
----
$ lttng untrack --userspace --pid --all
----

Whitelist:

-------------------------------
[ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ]
-------------------------------

Commands:

[role="term"]
----
$ lttng enable-event --userspace ...
$ lttng start
$ # ...
$ lttng track --userspace --pid=3,5
----

Whitelist:

-------------------------------
[ ] [ ] [ ] [3] [ ] [5] [ ] [ ]
-------------------------------

Command:

[role="term"]
----
$ lttng track --userspace --pid=2
----

Whitelist:

-------------------------------
[ ] [ ] [2] [3] [ ] [5] [ ] [ ]
-------------------------------


include::common-cmd-options-head.txt[]


Domain
~~~~~~
One of:

option:-k, option:--kernel::
    Untrack resources tracked in the Linux kernel domain.

option:-u, option:--userspace::
    Untrack resources tracked in the user space domain.


Target
~~~~~~
option:-s, option:--session='SESSION'::
    Untrack resources in the tracing session named 'SESSION' instead of
    the current tracing session.


Untracking
~~~~~~~~~~
option:-a, option:--all::
    Used in conjunction with an empty option:--pid option: untrack _all_
    process IDs (clear the whitelist).

option:-p ['PID'[,'PID']...], option:--pid[='PID'[,'PID']...]::
    Untrack process IDs 'PID' (remove them from the current whitelist).
+
The 'PID' argument must be omitted when also using the option:--all
option.


include::common-cmd-help-options.txt[]


include::common-cmd-footer.txt[]


SEE ALSO
--------
man:lttng-track(1),
man:lttng(1)
