Chapter 4. Charts

Charts in the Intel® Trace Analyzer are graphical or alphanumerical diagrams that are parameterized with a time interval, a process grouping and a function grouping (see Section 9.2) and an optional filter. Together they define the structure in which data is presented and the amount of data to be displayed.

The Charts supported by the Intel Trace Analyzer is divided into:

  1. Timelines: the Event Timeline, the Qualitative Timeline, the Quantitative Timeline and the Counter Timeline.

  2. Profiles: the Function Profile, the Message Profile and the Collective Operations Profile.

Charts are grouped into Views. These Views provide ways to choose the time interval, the process grouping and optional filters that all Charts in the View use. For more details on Views, refer to Chapter 3.

While the former show trace data in graphical form over a horizontal axis representing runtime, the latter show statistical data. All these Charts are found under Views Menu->Charts. Opening a file in the Intel Trace Analyzer, displays a View containing the Function Profile Chart (showing the Flat Profile tab) for the opened file.

The following sections describe each Chart in detail. For each Chart there is a subsection about Mouse Hovering, the context menu, the settings dialog box, the effects of filtering and tagging and the effects of aggregation, if it is applicable.

4.1. Event Timeline

The Event Timeline provides a graphical display of the individual process' activities.

Figure 4-1. The Event Timeline

The horizontal axis represents an interval of the runtime of the inspected program. Vertical bars show the function in which the process is. The bars consist of rectangles labeled with the current function's name and in its color. Black lines indicate messages sent between processes; they connect the sender and receiver processes.Blue lines, forming a grid, represent collective operations, such as broadcast or reduce operations. The status bar at the bottom of this panel shows information on events under the mouse cursor. By default, the entire runtime of the trace is visible. To get a better impression on the visualization primitives, use zooming. Zooming and navigation are explained in detail in Section 3.1.3.

4.1.1. Mouse Hover

When the mouse pointer hovers over the Event Timeline, its exact position in terms of time is shown in the status bar. The status bar also shows which function, collective operations or messages are under the mouse cursor at the moment. The status bar of the Event Timeline Chart in Figure 4-1, shows that the mouse is currently at 2.01214 seconds over a message from P13 to P14.

4.1.2. Event Timeline Settings

Use the Event Timeline Settings to change the display settings, the layout settings and the colors of the Event Timeline Chart. The display options, which are enabled using check boxes, include

  • Process Labels: Displays the name of the process or process group to the left.

  • Function Labels: Displays the name of the function or function group inside the colored bars

  • Timescale at top: Displays a timescale above the Chart

  • Timescale at bottom: Displays a timescale below the Chart

  • Messages over Collective Operations: This specifies what is drawn first. If enabled, messages are drawn over the collective operations such that the messages are seen and the collective operations are concealed. If disabled, the collective operations are drawn over the messages.

Figure 4-2. Settings dialog box for the Event Timeline

The Layout option consists of two sliders and two check boxes. The slider Minimal Spacing Between Bars adjusts the space between the function bars. The slider Minimal Bar Height adjusts the height of the function bar itself. For both, the unit is pixels.

The Adjust Minimal Bar Height to Labels check box alters the size of the bars. Check this box to make the bars tall enough to display a function label. This option is checked by default.

The check box Use Available Vertical Space influences the overall vertical layout of the bars and is also checked by default. For a better understanding, refer to Figure 4-3 where the Event Timeline is shown without checking the given option and Figure 4-4 where the Use Available Vertical Space is checked.

Figure 4-3. Event Timeline: Use Available Vertical Space unchecked

Figure 4-4. Event Timeline: Use Available Vertical Space checked

To change the colors of the functions, messages or collective operations, use the three Colors buttons at the bottom of the Settings dialog box. Function Colors call up the Function Group Color Editor (Section 5.5). To change the color in which the messages are displayed, click on the Message Color button. This opens a dialog box where the required color is chosen. Change the color of the Collective Operations in the same way if need be.

Colors chosen for messages and collectives are local to the Event Timeline Chart. Colors chosen for functions or function groups are shared by all Charts and Views belonging to the same trace file.

4.1.3. The Context Menu

Apart from the general options common to all Charts (see Section 4.8), the context menu of the Event Timeline provides details pertaining to the function, the message or the Collective Operation. For example, to access details about a particular message in the Event Timeline, right-click on the message and select the option Details on Message. This opens a new dialog box displaying information on sender, receiver and other message attributes. This is further explained in Section 5.6.

When invoked for a collective operation the context menu will offer the entry Zoom to Collective that will set the View's time interval to the time covered by the respective collective operation.

Figure 4-5. Event Timeline: context menu example

Furthermore, the context menu has an entry to ungroup/regroup the function, which works the same way in every Chart. To display functions, messages and/or collective operations, select Show from the context menu. Select/deselect one or more of the above from the sub-menu that opens on clicking Show.

The context menu entries that are common to all Charts are explained in Section 4.8.

4.1.4. Filtering and Tagging

Tagged functions in the Event Timeline are shown with a frame around them and with the function label rendered in a bold font. Tagged messages and collectives are shown with thicker lines.

Figure 4-6. Tagging functions in a process in the Event Timeline

Figure 4-6 shows an Event Timeline where the MPI function in process number 8 (P8) is tagged. On filtering the Event Timeline with the same clause (MPI in P8), only the MPI functions of P8 pass the filter and are displayed, while all other functions and processes are filtered out as shown in Figure 4-7. More on tagging and filtering is available in Section 9.3.

Figure 4-7. Filtering functions in a process in the Event Timeline