## Call tree comparison |

| The call tree comparison is one of the CPU comparisons. It is created by invoking the CPU comparison wizard. For more information on snapshot comparisons, please see the snapshot comparison overview.

| The wizard has the following additional steps: Select snapshots The call tree comparison compares two snapshot files. In this step, you select the first and the second snapshot file for the comparison. The combo boxes contain all snapshot files that have been added to the snapshot selector. You can use the same snapshot file for the first and second snapshot file, in which case the thread selections in the next step must be different. Thread selection In this step, you choose for which threads the comparison should be made. By default all threads are selected, you can restrict the thread selection to single thread groups or single threads. View parameters In this steps you can select thread status and aggregation level, just as for the call tree view. In addition, you can choose whether to calculate differences of total call times or of average call times (total time divided by invocation count). Note that if "Sampling" was used as the call tree collection method, the invocation count is not available and this setting will not have any effect.

| Each node in the tree has the same format as in the call tree view, except that the time and invocations are the differences between the second and the first snapshot. Each node has an optional bar chart at the beginning, Increases are painted in red, while decreases are painted in green. In the view settings dialog you can choose whether you want this bar chart to display absolute changes or the percentage of the change. The other value is displayed in parentheses. This setting also determines how sibling nodes are sorted.

| By default, only call stacks that are present in both snapshot files and that have changed from one snapshot file to the other are displayed. You can change this behavior in the view settings dialog.