SYNOPSIS
lttngtoptrace [OPTIONS] [EXECUTABLE]
DESCRIPTION
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 kernel
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
- -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 repeated)
- -o <filename>
- In textdump, output the log in <filename>
- EXECUTABLE
-
Program to run and connect the tracer (can be combined with other options to see the trace of other processes)
REQUIREMENTS
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
BUGS
Some highlighting problems with -a
CREDITS
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 http://www.efficios.com/babeltrace for more information on Babeltrace and the Common Trace Format. See http://lttng.org for more information on the LTTng project.
Mailing list for support and development: <[email protected]>.
You can find us on IRC server irc.oftc.net (OFTC) in #lttng.