When starting KCachegrind with a profile data file as argument, or after loading one with File → Open, you will see a navigation panel containing the function list at the left; and, on the right the main part, an area with views for a selected function. This view area can be arbitrarily configured to show multiple views at once.

At first start, this area will be divided into a top and a bottom part, each with different tab-selectable views. To move views, use the tabs' context menu, and adjust the splitters between views. To switch quickly between different viewing layouts, use View → Layout → Go to Next (Ctrl+→) and View → Layout → Go to Previous (Ctrl+←).

The active event type is important for visualization: for Callgrind, this is, for example, cache misses or cycle estimation; for OProfile, this is “Timer” in the simplest case. You can change the event type via a combobox in the toolbar or in the Event Type view. A first overview of the runtime characteristics should be given when you select function main in the left list; look then at the call graph view. There, you see the calls occurring in your program. Note that the call graph view only shows functions with high event count. By double-clicking a function in the graph, it will change to show the called functions around the selected one.

To explore the GUI further, in addition to this manual, also have a look at the documentation section on the Web site. Also, every widget in KCachegrind has “What's this” help.