.TH "LTTNGTOP" "1" "April 18, 2012" "" ""

.SH "NAME"
lttngtop \(em LTTng Trace Viewer

.SH "SYNOPSIS"

.PP
.nf
lttngtop INPUT
.fi
.SH "DESCRIPTION"

.PP

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.
.SH "OPTIONS"

.TP
.BR "INPUT"
Input trace path

.SH "TRACE REQUIREMENTS"

.PP

LTTngTop requires that the pid, procname, tid and ppid context information
are enabled during tracing.
.PP

.PP
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.
.PP

.PP
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.
.PP

.nf
lttng create lttngtop
lttng enable-event -k -a
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
lttng start
sleep 10
lttng stop
lttng destroy
.fi

.SH "SEE ALSO"

.PP
babeltrace(1), babeltrace-log(1), lttng(1), lttng-ust(3), lttng-sessiond(8)
.PP
.SH "BUGS"

.PP
No knows bugs at this point.

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.
.SH "CREDITS"

LTTngTop is distributed under the GPLv2 license. See the LICENSE file
in the source tree for details.

.PP
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.
.PP
Mailing list for support and development: <lttng-dev@lists.lttng.org>.
.PP
You can find us on IRC server irc.oftc.net (OFTC) in #lttng.
.PP

.SH "AUTHORS"

.PP
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>
.PP