lttng-track(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | ENVIRONMENT VARIABLES | FILES | EXIT STATUS | BUGS | RESOURCES | COPYRIGHTS | THANKS | AUTHORS | SEE ALSO | COLOPHON

LTTNG-TRACK(1)                LTTng Manual                LTTNG-TRACK(1)

NAME         top

       lttng-track - Add one or more entries to an LTTng resource
       tracker

SYNOPSIS         top

       lttng [GENERAL OPTIONS] track (--kernel | --userspace)
             [--session=SESSION] (--pid=PID[,PID]... | --all --pid)

DESCRIPTION         top

       The lttng track commands adds one or more entries to a resource
       tracker.

       A resource tracker is a whitelist of resources. Tracked resources
       are allowed to emit events, provided those events are targeted by
       enabled event rules (see lttng-enable-event(1)).

       Tracker entries can be removed from the whitelist with
       lttng-untrack(1).

       As of this version, the only available tracker is the PID
       tracker. The process ID (PID) tracker follows one or more process
       IDs; only the processes with a tracked PID are allowed to emit
       events. By default, all possible PIDs on the system are tracked:
       any process may emit enabled events (equivalent of lttng track
       --pid --all for all domains).

       With the PID tracker, it is possible, for example, to record all
       system calls called by a given process:

           # lttng enable-event --kernel --all --syscall
           # lttng track --kernel --pid=2345
           # lttng start

       If all the PIDs are tracked (i.e. lttng track --pid --all, which
       is the default state of all domains when creating a tracing
       session), then using the track command with one or more specific
       PIDs has the effect of first removing all the PIDs from the
       whitelist, then adding the specified PIDs.

   Example
       Assume the maximum system PID is 7 for this example.

       Initial whitelist:

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

       Command:

           $ lttng track --userspace --pid=3,6,7

       Whitelist:

           [ ] [ ] [ ] [3] [ ] [ ] [6] [7]

       Command:

           $ lttng untrack --userspace --pid=7

       Whitelist:

           [ ] [ ] [ ] [3] [ ] [ ] [6] [ ]

       Command:

           $ lttng track --userspace --pid=1,5

       Whitelist:

           [ ] [1] [ ] [3] [ ] [5] [6] [ ]

       It should be noted that the PID tracker tracks the numeric
       process IDs. Should a process with a given ID exit and another
       process be given this ID, then the latter would also be allowed
       to emit events.

       See the lttng-untrack(1) for more details about removing entries.

OPTIONS         top

       General options are described in lttng(1).

   Domain
       One of:

       -k, --kernel
           Track resources in the Linux kernel domain.

       -u, --userspace
           Track resources in the user space domain.

   Target
       -s SESSION, --session=SESSION
           Track resources in the tracing session named SESSION instead
           of the current tracing session.

   Tracking
       -a, --all
           Used in conjunction with an empty --pid option: track all
           process IDs (add all entries to the whitelist).

       -p [PID[,PID]...], --pid[=PID[,PID]...]
           Track process IDs PID (add them to the current whitelist).

           The PID argument must be omitted when also using the --all
           option.

   Program information
       -h, --help
           Show command help.

           This option, like lttng-help(1), attempts to launch
           /usr/bin/man to view the command’s man page. The path to the
           man pager can be overridden by the LTTNG_MAN_BIN_PATH
           environment variable.

       --list-options
           List available command options.

ENVIRONMENT VARIABLES         top

       LTTNG_ABORT_ON_ERROR
           Set to 1 to abort the process after the first error is
           encountered.

       LTTNG_HOME
           Overrides the $HOME environment variable. Useful when the
           user running the commands has a non-writable home directory.

       LTTNG_MAN_BIN_PATH
           Absolute path to the man pager to use for viewing help
           information about LTTng commands (using lttng-help(1) or
           lttng COMMAND --help).

       LTTNG_SESSION_CONFIG_XSD_PATH
           Path in which the session.xsd session configuration XML
           schema may be found.

       LTTNG_SESSIOND_PATH
           Full session daemon binary path.

           The --sessiond-path option has precedence over this
           environment variable.

       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.

FILES         top

       $LTTNG_HOME/.lttngrc
           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.

       $LTTNG_HOME/lttng-traces
           Default output directory of LTTng traces. This can be
           overridden with the --output option of the lttng-create(1)
           command.

       $LTTNG_HOME/.lttng
           User LTTng runtime and configuration directory.

       $LTTNG_HOME/.lttng/sessions
           Default location of saved user tracing sessions (see
           lttng-save(1) and lttng-load(1)).

       /usr/local/etc/lttng/sessions
           System-wide location of saved tracing sessions (see
           lttng-save(1) and lttng-load(1)).

           Note

           $LTTNG_HOME defaults to $HOME when not explicitly set.

EXIT STATUS         top

       0
           Success

       1
           Command error

       2
           Undefined command

       3
           Fatal error

       4
           Command warning (something went wrong during the command)

BUGS         top

       If you encounter any issue or usability problem, please report it
       on the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-
       tools>.

RESOURCES         top

       •   LTTng project website <https://lttng.org>

       •   LTTng documentation <https://lttng.org/docs>

       •   Git repositories <http://git.lttng.org>

       •   GitHub organization <http://github.com/lttng>

       •   Continuous integration <http://ci.lttng.org/>

       •   Mailing list <http://lists.lttng.org> for support and
           development: lttng-dev@lists.lttng.org

       •   IRC channel <irc://irc.oftc.net/lttng>: #lttng on
           irc.oftc.net

COPYRIGHTS         top

       This program is part of the LTTng-tools project.

       LTTng-tools is distributed under the GNU General Public License
       version 2 <http://www.gnu.org/licenses/old-
       licenses/gpl-2.0.en.html>. See the LICENSE
       <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file
       for details.

THANKS         top

       Special thanks to Michel Dagenais and the DORSAL laboratory
       <http://www.dorsal.polymtl.ca/> 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.

AUTHORS         top

       LTTng-tools was originally written by Mathieu Desnoyers, Julien
       Desfossez, and David Goulet. More people have since contributed
       to it.

       LTTng-tools is currently maintained by Jérémie Galarneau
       <mailto:jeremie.galarneau@efficios.com>.

SEE ALSO         top

       lttng-untrack(1), lttng(1)

COLOPHON         top

       This page is part of the LTTng-Tools (    LTTng tools) project.
       Information about the project can be found at 
       ⟨http://lttng.org/⟩.  It is not known how to report bugs for this
       man page; if you know, please send a mail to man-pages@man7.org.
       This page was obtained from the project's upstream Git repository
       ⟨git://git.lttng.org/lttng-tools.git⟩ on 2019-11-19.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2019-11-14.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

LTTng 2.12.0-pre               10/29/2018                 LTTNG-TRACK(1)

Pages that refer to this page: lttng(1)lttng-enable-event(1)lttng-untrack(1)