What you will typically want is to read sections 2 and 3 : install LTTng from
sources and use it.
-These operations are made for installing the LTTng 0.12 tracer on a linux 2.6.X
-kernel. You will also find instructions for installation of LTTV 0.8.x : the
+These operations are made for installing the LTTng 0.67 tracer on a linux 2.6.X
+kernel. You will also find instructions for installation of LTTV 0.12.x : the
Linux Trace Toolkit Viewer.
To see the list of compatibilities between LTTng, ltt-control, LTTV and
(Debian : libc6, libc6-dev)
(Fedora : glibc, glibc)
+* Reminder
+
+See the list of compatibilities between LTTng, ltt-control, LTTV and
+markers-userspace at :
+http://ltt.polymtl.ca > LTTng+LTTV versions compatibility
+
+
* Getting the LTTng packages
these commands load all LTT modules. Depending on what options you chose to
compile statically, you may not need to issue all these commands.
-modprobe ltt-control
+modprobe ltt-trace-control
modprobe ltt-marker-control
modprobe ltt-tracer
modprobe ltt-serialize
modprobe mm-trace
modprobe net-trace
modprobe fs-trace
+modprobe syscall-trace
+modprobe trap-trace
#if locking tracing is wanted, uncomment the following
#modprobe lockdep-trace
You can automate at boot time loading the ltt-control module by :
cp /etc/modules /etc/modules.bkp
-echo ltt-control >> /etc/modules
+echo ltt-trace-control >> /etc/modules
echo ltt-marker-control >> /etc/modules
echo ltt-tracer >> /etc/modules
echo ltt-serialize >> /etc/modules
Start tracing :
-lttctl -n trace -d -l /mnt/debugfs/ltt -t /tmp/trace
+lttctl -C -w /tmp/trace1 trace1
Stop tracing and destroy trace channels :
-lttctl -n trace -R
+lttctl -D trace1
see lttctl --help for details.
(note : to see if the buffers has been filled, look at the dmesg output after
lttctl -R or after stopping tracing from the GUI, it will show an event lost
count. If it is the case, try using larger buffers. See lttctl --help to learn
-how.)
+how. lttv now also shows event lost messages in the console when loading a trace
+with missing events or lost subbuffers.)
* Use text mode LTTV
The following lttctl commands take an hybrid trace :
Create trace channel, start lttd on normal channels, start tracing:
-lttctl -n tracename -d -l /mnt/debugfs/ltt -t /tmp/trace1 -m hybrid
+lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
Stop tracing, start lttd on flight recorder channels, destroy trace channels :
-lttctl -n tracename -f -l /mnt/debugfs/ltt -t /tmp/trace1 -m hybrid
-
+lttctl -D -w /tmp/trace2 trace2
-We will need to tweak what we consider "important" medium rate events. For
-instance, thread branding events are actually considered a "high rate" event
-when it should be considered "medium rate". The same should apply for the
-state dump process enumeration.
+Each "overwrite" channel is flight recorder channel.
* Flight recorder mode
The flight recorder mode writes data into overwritten buffers for all channels,
-including control channels, except for the facilities tracefiles.
+including control channels, except for the facilities tracefiles. It consists of
+setting all channels to "overwrite".
The following lttctl commands take a flight recorder trace :
-lttctl -n trace -c -m flight
-lttd -n -d -t /tmp/trace -c /mnt/debugfs/ltt/trace
-lttctl -n trace -s
-.. do stuff
-lttctl -n trace -q
-lttd -f -d -t /tmp/trace -c /mnt/debugfs/ltt/trace
-lttctl -m trace -r
+lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
+...
+lttctl -D -w /tmp/trace3 trace3
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