update quickstart

git-svn-id: http://ltt.polymtl.ca/svn@2818 04897980-b3bd-0310-b5e0-8ef037075253

diff --git a/ltt/branches/poly/QUICKSTART b/ltt/branches/poly/QUICKSTART
index 45c9cd57e80430040b2d3064c20a4b4f16b6129f..f3501ac05d4312fba32672c910e65c03409b63db 100644 (file)
--- a/ltt/branches/poly/QUICKSTART
+++ b/ltt/branches/poly/QUICKSTART
@@ -419,6 +419,31 @@ of the events to the clipboard and paste them in the GUI by clicking on the
 bottom right label "Current time". Support for this type of filtering should
 be added to the filter module soon.
 
+* Flight recorder mode
+
+Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
+hybrid. It can be especially useful when studying big workloads on a long period
+of time.
+
+When using this mode, the most important, low rate control information will be
+recorded during all the trace by lttd (i.e. process creation/exit). The high
+rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
+flight recorder buffer (now named flight-channelname_X).
+
+The following lttctl commands take an hybrid trace :
+
+Create trace channel, start lttd on normal channels, start tracing:
+lttctl -n tracename -d -l /mnt/relayfs/ltt -t /tmp/trace1 -m hybrid
+
+Stop tracing, start lttd on flight recorder channels, destroy trace channels :
+lttctl -n tracename -f -l /mnt/relayfs/ltt -t /tmp/trace1 -m hybrid
+
+
+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.
+
 
 ***********************************************************
 ** Section 4 * Adding new instrumentations with genevent **