More on the TOI, POI, & GOI
A tips reader sent an email about last week's tip that said "This tip is in desperate need of an example for those of us who run mostly serial applications." So this tip does just that.
The following illustration shows a control group that has five executing processes. Similarly, all threads in each process have five threads. The horizontal threads are manager threads; that is, they are created by the operating system to help manage your application. This means that they are not worker threads. Each of the processes has three vertical threads that actually do the work. However, one of these threads really doesn't contribute so it is drawn differently than the other two. (You can use the CLI's dworker command to tell TotalView that it isn't a worker thread.)
The thread with the red background is the TOI (Thread of Interest). This is the thread that is displayed in the Process Window. If you are using the CLI, the TOI is either the current focus or a temporary focus set using the dfocus command.
Because the TOI is known, TotalView knows that:
- The POI is the process that contains the thread with the red background.
- The GOI can be share group 2 or the control group. TotalView determines which one based on what is selected in the scope pulldown list.
- If your selection isn't one of the Group elements, the GOI is irrelevant. If you've select a thread, the GOI and the POI are irrelevant.
To be continued ...
You can find tips that we've already sent out in our Tip Archive
Help us improve these tips!
