LTTNGTOPTRACE(1)                                            LTTNGTOPTRACE(1)

NAME         top

       lttngtoptrace — Live textual LTTng Trace Viewer

SYNOPSIS         top

       lttngtoptrace [OPTIONS] [EXECUTABLE]

DESCRIPTION         top

       Lttngtoptrace is a live textual LTTng trace viewer, it allows to
       easily (one command) start a LTTng session and view the live events.
       The intent is to do something similar to strace but less intrusive
       and more flexible:
       - run a command and see it's kernel trace almost instantly without slowing it
         down too much (buffered at most 1 second) in combination with the trace of
         any other process or the whole system
       - follow multiple processes and/or the whole system
       - follow the children of all attached processes
       - attach to processes by name and/or pid
       - actual time taken by the system calls (with reminder of start timestamp)
       - sched_switch events to know the context switches that occurred for the
         process we are interested in
       - current CPU (to see the migrations)
       - highlight the trace of a selection of processes while tracing the whole
         system to easily see the interactions
       - arbitrary kprobe additions to see if a process hits a certain place in the

       Only a subset of the LTTng events are enabled (the statedump,
       sched_switch, sched_process_fork and all the system calls).

       The events are displayed with additionnal context information than
       just the raw LTTng trace (such as the current process name/PID/TID,
       the start/end time of the current system call, the delay since the
       last displayed event (filtering aware)).

OPTIONS         top

       -f     Follow threads associated with selected PIDs

       -p     Comma-separated list of PIDs to display (in addition to the
              eventual executed program)

       -n     Comma-separated list of procnames to display (in addition to
              the eventual executed program)

       -a     In textdump mode, display all events but write in bold the
              processes we are interested in (-f and -p)

       -k     kprobes to insert (same format as lttng enable-event, can be

       -o <filename>
              In textdump, output the log in <filename>

              Program to run and connect the tracer (can be combined with
              other options to see the trace of other processes)

REQUIREMENTS         top

       A working installation of LTTng >= 2.4, the appropriate rights for
       the user to create a kernel trace and start daemons (sudo is tried in
       case the user is not root), Babeltrace = 1.2.4, LTTngTop = 0.3

SEE ALSO         top

       lttngtop(1), babeltrace(1), babeltrace-log(1), lttng(1), lttng-
       ust(3), lttng-sessiond(8)

BUGS         top

       Some highlighting problems with -a

CREDITS         top

       lttngtoptrace is a wrapper on top of LTTngTop released under the
       GPLv2 license.  See the LICENSE file in the source tree for details.

       A Web site is available at for
       more information on Babeltrace and the Common Trace Format. See for more information on the LTTng project.

       Mailing list for support and development: <lttng->.

       You can find us on IRC server (OFTC) in #lttng.

AUTHORS         top

       LTTngTop was originally written and is maintained by Julien Desfossez

COLOPHON         top

       This page is part of the lttngtop (    LTTng top-like application)
       project.  Information about the project can be found at 
       ⟨⟩.  It is not known how to report bugs for this man
       page; if you know, please send a mail to  This
       page was obtained from the project's upstream Git repository ⟨git⟩ on
       2017-03-13.  If you discover any rendering problems in this HTML ver‐
       sion 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 man‐
       ual page), send a mail to

                                June 01, 2015               LTTNGTOPTRACE(1)