Timeline view

Overview

The Timeline view displays the application's activity for the entire trace duration, with each thread having a histogram showing the CPU usage based on the number of profile samples collected over time.

This view helps identify the threads and time ranges with CPU activity (or lack thereof due to locks and I/O). It also has features for filtering the entire profile data to consider only specific threads and time ranges.

The view has three parts:

a main toolbar at the top, with general action buttons.
a graph showing the activity of the entire application, with the activity across all threads combined.
for each thread, a graph showing the thread's activity. The thread list is sorted by the execution time in descending order.

The All Threads entry displays the trace duration range on top, split into time units. The maximum number of CPU cores the application uses is displayed on the left. Individual threads use, at most, one core.

Each individual thread entry has the following values and buttons:

thread visibility button indicating if the samples from the thread are included in the profile data or not. Click to toggle between included or excluded state .
thread context menu button that shows thread filtering actions.
the thread ID number.
the thread execution time as a sum of the duration of all samples that ran on the thread.
if available in the trace, the thread name.

Mouse actions

Moving the mouse over the graphs shows the time position and the approximate number of cores used at that point.

Hovering with the mouse over the graph shows a preview popup with the slowest call path (stack trace) active at that point.

Clicking a thread ID or name creates a time range selection for the thread covering the entire trace duration. If Sync is enabled in the toolbar, all functions executing on the selected thread are also selected in the other profiling views.

Selecting a time range

To select a time range that includes all threads, click and drag over the desired range in the top All Threads graph. The duration of the current selection is displayed in the top All Threads graph. Note that if some threads are excluded, the selection will not consider them.
To select a time range for a single thread, click and drag over the desired range in the specific thread graph. To include another thread in the same time range, from the thread action menu, click Include thread* or use the icon.

Note

If the Sync option is enabled, selecting a time range also selects the functions executing during that time in the other profiling views, considering if all threads or a subset are included.

Filtering the profile

The entire profile can be filtered so that only specific threads and time ranges are displayed, with the profiling views updated to include only the profile samples accepted by the filter. The active filter is displayed in both the toolbar and the application menu bar.

Filtering based on a time range

Select the desired time range, then double-click the selection (alternatively, right-click the selection and click "Filter to Time Range*). If a single thread is selected, a filter that displays only the selected thread and excludes all others is also added.

Filtering based on a thread

There are multiple ways to filter based on one or multiple threads, optionally combined with a time range filter.

to include a single thread and exclude all others, double-click the thread ID or click Filter to Thread from the thread action menu.
to include another thread, click the icon or click Include Thread.
to include all threads with the same name and exclude all others, click Filter to Same Name Threads.
to include all threads with the same name, click Filter to Same Name Threads.
to exclude a thread, click the icon or click Exclude Thread.
to exclude all threads with the same name, click Exclude Same Name Threads.

Example of a filter including a single thread (58540) and a time range of ~2 sec. Excluded threads and time ranges are displayed using faded colors. Use the X buttons next to Time and Threads in the toolbar to remove the filter.

Marking samples

The samples corresponding to a function instance can be marked from the Flame Graph view using the right-click context menu of a node and selecting a color from the Mark In Timeline menu entry.

The Markers menu in the toolbar displays the currently marked functions.
Click on a menu entry to remove the marker.

View interaction

Toolbar

Button	Description
	Resets the view to it's original state, displaying the thread graphs for the entire trace duration.
	Zooms out the thread graphs and updates the time units.
	Zooms in the thread graphs and updates the time units.
	If enabled, selecting a time range also selects executing during that time in the other profiling views.
Markers	Search for nodes with a specific function name using a case-insensitive substring search. Press the Escape key to reset the search or the X button next to the input box.

Documentation in progress

View options