APS View

The APS View displays information about the adaptive partitioning scheduling (APS) on a target.

For more information about adaptive partitioning, see:
To configure APS for a connected target, you must use the Target Navigator. The APS View shows APS-related statistics and settings in multiple panels within its top pane; the subsections that follow describe these panels. The bottom pane displays graphs of the partition budgets and CPU usage.

Screenshot of APS View showing Partitions panel, which reveals parent partition and budget for all partitions, and Partition Budgets piechart, which illustrates CPU resource assignments to all partitions

APS System Information

This panel displays the following APS state fields:
  • current number of partitions
  • partition, process, and thread IDs where the last bankruptcy (exhaustion of critical budget) occurred
  • average number of computational cycles executed per millisecond
  • averaging windows, which are time intervals used by the scheduler to calculate CPU usage
  • APS security flags in effect, which determine who can add partitions and modify their attributes
  • relative and overall times that the system was idle for longer than the second and third averaging windows (by default, these are 1 and 10 seconds)
Note: When you add or modify partitions using the SchedCtl() C library function or the aps utility, the changes are reflected in this and all other panels when the view is refreshed.


In this panel, the Partition Information table shows these details for each partition:
  • partition name
  • parent partition
  • partition ID
  • budget, which is the percentage of CPU time guaranteed for the partition
  • critical budget, which is the time that critical threads can run over budget

On the right, the Partition Child Processes and Threads area lists the processes and threads assigned to each partition. The list is interactive, allowing you to move processes and threads between partitions by dragging and dropping. Moving one of these items might cause others to be moved as well.

Partition Statistics

This panel displays CPU usage statistics related to the averaging windows. The table shows the relative CPU times during which threads in each partition ran for longer than the second and third windows. It also shows the total CPU times that all or just critical thread runtimes exceeded those two windows.

By default, the second and third averaging windows are 1 and 10 seconds, but you can change them by setting a new first window, through SchedCtl() or aps. The second window is set to 10 times this duration and the third window to 100 times.

APS Bankruptcy

In this panel, the Bankruptcy Information table lists the IDs of each partition's notification process and thread (which handle the event emitted when the partition exhausts its critical budget and thus, becomes bankrupt), and the IDs of the process and thread running when the last bankruptcy occurred.

On the right, the Bankruptcy Flags area lists the system's bankruptcy settings, which determine how it reacts to a bankruptcy. You can change the bankruptcy settings through SchedCtl() or aps.

Partition and CPU usage graphs

The APS View contains the following graphs in multiple tabs:
Partition Budgets
This piechart shows the partition budgets, which are the percentages of CPU time assigned to the partitions.
CPU Usage
This line chart shows recent CPU usage for each partition.
Critical Time Usage
This line chart shows critical time usage for each partition, which refers to the time (in milliseconds) that critical threads within a partition ran over budget.