documentation: Add documentation for Latency views

[deliverable/tracecompass.git] / doc / org.eclipse.tracecompass.doc.user / doc / User-Guide.mediawiki

diff --git a/doc/org.eclipse.tracecompass.doc.user/doc/User-Guide.mediawiki b/doc/org.eclipse.tracecompass.doc.user/doc/User-Guide.mediawiki
index 5c36064ca0557133865529c6a0476de41e5429b9..9e845ea4ebf26556fd197a24914630fb32449d86 100644 (file)
--- a/doc/org.eclipse.tracecompass.doc.user/doc/User-Guide.mediawiki
+++ b/doc/org.eclipse.tracecompass.doc.user/doc/User-Guide.mediawiki
@@ -1430,15 +1430,6 @@ To refresh the remote host information, select any node in the tree of the Contr
 
 Upon successful operation, the tree in the Control View will be refreshed with the remote host configuration.
 
-=== Quantifing LTTng overhead (Calibrate) ===
-
-The LTTng calibrate command can be used to find out the combined average overhead of the LTTng tracer and the instrumentation mechanisms used. For now, the only calibration implemented is that of the kernel function
-instrumentation (kretprobes). To run the calibrate command, select the a domain (e.g. '''Kernel'''), click the right mouse button on the domain tree node. A context-sensitive menu will show. Select the '''Calibrate''' menu item.
-
-[[Image:images/LTTng2CalibrateAction.png]]
-
-Upon successful operation, the calibrate command is executed and relevant information is stored in the trace. Note: that the trace has to be active so that to command as any effect.
-
 === Importing Session Traces to a Tracing Project ===
 
 To import traces from a tracing session, select the relevant session and click on the '''Import''' Button. Alternatively, click the right mouse button on the session tree node and select the menu item '''Import...''' from the context-sensitive menu.
@@ -2595,6 +2586,34 @@ The following screenshot shows the result of the preceding example on a LTTng Ke
 
 [[Image:images/XML_xy_chart.png| XML XY chart]]
 
+= Latency Analyses =
+
+Trace Compass offers a feature called Latency analysis. This allows an analysis to return intervals and these intervals will be displayed in four different views. An example analysis is provided with kernel system call latencies being provided. The available views are: 
+
+* System Call Latencies 
+A '''table''' of the raw latencies. This view is useful to inspect individual latencies.
+
+ [[Image:images/LatenciesTable.png| Latency Table example - System Call Latencies]]
+
+
+* System Call Latency vs Time
+A time aligned '''scatter chart''' of the latencies with respect to the current window range. This view is useful to see the overall form of the latencies as they arrive. 
+
+[[Image:images/LatenciesScatter.png| Latency Scatter Chart example - System Call Latency vs Time]]
+
+
+* System Call Latency Statistics
+A view of the total '''statistics''' of the latencies. These show the ''minimum'', ''maximum'', ''average'' and ''standard deviation'' of the latencies when applicable. This tool is useful for finding the outliers on a per-category basis. 
+
+[[Image:images/LatenciesStatistics.png| Latency Statistics example - System Call Latency Statistics]]
+
+
+* System Call Density 
+A '''density''' view, analyzing the current time range. This is useful to find global outliers.
+
+[[Image:images/LatenciesDensity.png| Latency Densities example - System Call Density]]
+
+
 = Limitations =
 
 * When parsing text traces, the timestamps are assumed to be in the local time zone. This means that when combining it to CTF binary traces, there could be offsets by a few hours depending on where the traces were taken and where they were read.