The Timeline view is the first view that you see when ARM Streamline opens a report. It provides you with high level information about the performance of your target during the capture session.
After you have successfully generated a report, Streamline opens it automatically and displays the Timeline view.
The Timeline view breaks up its data into bins, a unit of time defined by the unit drop down menu at the top of the view. For example, if the unit is set to 100ms, every color-coded bin in the processes section represents trace data captured during a 100ms window.
Streamline collects data for the charts from hardware and software performance counter resources. Use the chart expansion control on the right side of the chart handle to increase the size of any chart.
The data is dependent on how you have configured your counters and the type of system you use. For SMP systems, the chart per core disclosure control enables you to expand the data to show collection per core.
Unlike the other charts in the Timeline view, the CPU Activity, GPU Vertex, and GPU Fragments charts are bar charts and the current selection in the processes section affects how they are displayed. When there is an active selection in the processes section the green bars change to reflect CPU activity caused by the selected processes. Streamline still displays the total activity in dark gray so that you can visually compare the selected processes CPU Activity values to the total.
The Processes section of the Timeline view shows you the active processes in each bin. The entries are derived from process/thread trace data from the Linux kernel scheduler. Weighted colors reflect the number of samples in each process or thread.
The process has started, but is dormant. It could be sleeping, waiting on user input, or waiting for some other process to finish.
- Yellow to red
Responsible for some percentage of total instructions during this bin. Red indicates a higher percentage.
The [idle] process is color-coded differently than the other processes in the Timeline view. When the system is fully idle, it is bright blue. When it is partially idle it is a lighter shade of blue, and when the system is fully active, it appears white.
In addition to the colored bins, the Processes sections contained colored dots that indicate that something triggered the process to delay. The color of the dots displayed depends on the cause of the delay:
An I/O operation caused the delay. The process stopped while a read or a write to disk occurred.
A mutex triggered the delay.
If you select a process or multiple processes, all the charts in the Timeline view that contain process specific data update to reflect only activity caused by the selected processes. All charts that do not contain the necessary process information are blanked out.
GPU Vertex and Fragment bar charts display only activity initiated by the selected processes. This allows you to differentiate between GPU activity caused by your application and activity resulting from other applications or system services.
The detail bars show functions with the most samples in the currently selected cross-section. Selecting a bar jumps you into the relevant context in the Call Paths view. Double-click on the relevant Capture Data to load more applications and decrease the number of bracketed entries in this list.
The Samples HUD can be turned on and off using the Samples HUD button in the toolbar.
X-Ray mode changes the process trace from an intensity map of time, to a mode that highlights core affinity. In this mode, the bars show the mapping of software threads to processor cores. Streamline supports dual-core and quad-core targets. The colors in X-Ray mode are:
Hovering the mouse cursor over a color-coded bin shows you which core the color identifies.
X-Ray mode is useful only in SMP systems. All entries in the processes section appear blue in a single core system report.
The process filter is located on the right-hand side of the
toolbar. Enter a regular expression in the field to filter the processes
in the processes section of the Timeline view. For example, if you enter
a standard string consisting only of letters, the processes section
updates to include only [idle], [kernel], and any processes that
contain the entered string. Regular expression strings are case
sensitive unless you include
(?i) in front of
your search expression.
The bar charts in the Timeline view update to display only activity from the remaining processes.
You can create bookmarks in the Timeline view, enabling you to label and quickly return to critical points in the Timeline view. To do so:
Double click in the timeline itself. The timeline is the numbered ruler above the charts in the Timeline view.
Give the new bookmark a title by entering it into the resulting field.
Choose a color for the bookmark by clicking on the color selector to the right of the bookmark entry field.
Use the Color dialog box to choose a color for the new bookmark.
After giving the bookmark a title and color, a bookmark now appears in the timeline. Hover over the bookmark to see an overlay that shows you the title of the bookmark and the time in the capture session. The overlay also provides two buttons:
- Edit bookmark
Use this button to change the title or color of the bookmark. Double-clicking on a bookmark has the same effect.
- Delete bookmark
Use this button to remove the bookmark from the Timeline.
If you scroll away from the bookmark, you can easily return to it by clicking on the colored mark in the timeline overview.
In addition to bookmarking you can also place a pin in a particular point in any chart of the Timeline view. To do so, click the Toggle Value Pin Mode button in the toolbar and click on a point in any chart.
In value pin mode, a gray line appears under your cursor, so that you can more precisely place each pin. Each value pin shows an overlay with the values of the chart at the location of the pin.
Click on a value pin to remove it.
The CPU activity, CPU Wait, GPU Vertex, and GPU fragments are special charts types. They have a button on the left side of the chart handle that enables you to select that chart as the current focus of the processes section. By default, this is set to the CPU activity chart.
If you click a Processes Focus button on one of the bar charts, the processes section updates to show a heat map of processes that contributed to activity in the newly selected bar chart. For example, if you click the Processes Focus button on the GPU Vertex chart, the processes section updates to show heat mapped activity for the GPU vertex processor only. The GPU charts are only available if you have captured data on a Mali-400 target and built the gator module to support Mali.
If you find Streamline to be slow and unresponsive, change the graphics quality by following these steps:
Select Window → Preferences.
Use the disclosure control to open DS-5.
Select Streamline from the list under DS-5.
Select the Use highest quality graphics checkbox.
By default, the Use highest quality graphics option is active.
If you use the counter configuration dialog to set up events-based sampling, a blue EBS tag appears in the toolbar of any Analysis Report you create using that configuration.
The tooltip that appears when you hover the mouse over the EBS tag tells you which counter you set as the basis for the events-based sampling and the threshold value. For more information on events-based sampling, see Events-based sampling.