|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | TRACE REQUIREMENTS | LIVE STREAMING | KEY BINDINGS | SEE ALSO | BUGS | CREDITS | AUTHORS | COLOPHON |
LTTNGTOP(1) LTTNGTOP(1)
lttngtop — LTTng Trace Viewer
lttngtop INPUT
Lttngtop is a ncurses interface for reading and browsing traces
recorded by the LTTng tracer and displaying various statistics. As of
now, the cpu usage, performance counters and per process/file I/O
bandwidth are displayed. This version currently only supports offline
traces, but a live version is in alpha and will be available for
testing soon.
INPUT Input trace path
LTTngTop requires that the pid, procname, tid and ppid context
information are enabled during tracing.
The command --create-local-session does all the required setup for a
local trace (that must be stopped and destroyed manually by the
user). And the command --create-live-session does all the required
setup for a live trace on localhost (it must also be stopped and
destroyed manually by the user).
If you want the CPU activity view, you need the sched_switch event,
if you want the I/O statistics, you need to enable the system call
tracing, and if you want the performance counters, you need to enable
them for the events you are interested in (or all of them). Note,
there is a hardware limitation for the number of performance counter
you can enable, check dmesg for information.
The following example creates a trace with all events enabled, the
mandatory context informations and three performance counters. It
assumes that you are running as root or with a user part of the
tracing group and a lttng-sessiond launched as root.
lttng create lttngtop
lttng enable-event -k lttng_statedump_start,lttng_statedump_end,lttng_statedump_process_state,lttng_statedump_file_descriptor,lttng_statedump_vm_map,lttng_statedump_network_interface,lttng_statedump_interrupt,sched_process_free,sched_switchsched_process_fork -s lttngtop
lttng enable-event -k --syscall -a -s lttngtop
lttng add-context -k -t pid -t procname -t tid -t ppid -t perf:cache-misses -t perf:major-faults -t perf:branch-load-misses -s lttngtop
lttng start lttngtop
sleep 10
lttng stop lttngtop
lttng destroy lttngtop
In addition to offline traces, LTTngTop can read traces while they
are being recorded. The official supported way of doing live
streaming is using lttng-tools >=2.4 and following the documentation
in live-reading-howto.txt of lttng-tools and README-LIVE of lttngtop.
An other experimental way of doing live tracing is with mmap, but
this requires some more work because is not officially supported and
requires out-of-tree patches to lttng-tools and babeltrace.
To use the network live-reading, the user only needs to specify the
relayd hostname or IP address with the option -r. For now, LTTngTop
will only connect to the first live session established on the relay,
but in a near future, the user will be able to choose which session
to attach to.
The default mode after attaching to a session is to start reading the
trace from this point in time. In order to read the trace from the
beginning, the user can specify the -b option.
´F2´: CPUTop
Switch to the CPUTop view which displays the CPU usage of each
process
´F3´: PerfTop
Switch to the PerfTop view which displays the performance
counters (PMU) value of each process (if enabled during
tracing)
´F4´: IOTop
Switch to the IOTop view which displays the I/O usage of each
process (as of now read and writes on any file descriptor
network or disk)
´Enter´: Process details
Display all relevant information for the process selected
´Space´: Highlight
Highlights the process under the blue line to make it easy to
find it across all views or toggle view in preference panel
´q´: Quit
Exit the program
´t´: Threads
Toggle threads display in CPUTop
´r´: Preferences
Display the preference menu for the current view, this menu
helps select the column displayed (only in PerfTop view for
now) and the column to sort, use 's' to sort and 'space' to
toggle the view
´s´: Sort
In preference view, sort on the currently selected line
´p´: Pause/Resume
Pause the display, hit again to resume the refresh (only works
when the trace has not been fully displayed)
´Right arrow´: Move forward in time
Display the next second of data, can be hit several time to
bypass the default 1 second refresh period to fast forward
´Left arrow´: Move backward in time
Display the previous second of data, automatically switch to
pause if not already enabled
´Up arrow´ / ´k´: Move UP the cursor
Move up the blue line to select processes
´Down arrow´ / ´j´: Move DOWN the cursor
Move down the blue line to select processes
´>': Sort the next column
Update the sorting to the next column
´<': Sort the previous column
Update the sorting to the previous column
babeltrace(1), babeltrace-log(1), lttng(1), lttng-ust(3), lttng-
sessiond(8)
The I/O history has some problems with the file names, and we are
missing some system calls parsing to have the complete I/O
accounting.
If you encounter any issues or usability problem, please report it on
our mailing list <lttng-dev@lists.lttng.org> to help improve this
project.
LTTngTop is distributed 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: <lttng-
dev@lists.lttng.org>.
You can find us on IRC server irc.oftc.net (OFTC) in #lttng.
LTTngTop was originally written by Julien Desfossez, with
contribution from Mathieu Bain for the I/O bandwidth view, and
suggestions and ideas from the team working with the LTTng project.
It is currently maintained by Julien Desfossez
<jdesfossez@efficios.com>
This page is part of the lttngtop ( LTTng top-like application)
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⟩ on
2017-07-05. 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 man-pages@man7.org
June 01, 2015 LTTNGTOP(1)