Showing Non-Parallel Nature of a Serial Node
You can use the Scalability analysis plugin to identify nodes that have no parallelism or to tell when an unlimited node is running serially.
For this example, use a source_node and a function_node connected to it. Set the following:
Select the function_node.
in the Node Concurrency field, enter 1 or serial. This makes the node run serially.
In the Node Weight field, enter 1.
Select the source_node.
In the Node Weight field, enter 1e-6.
Go to the Edit > Properties > TBB.
Set the concurrency specification to 1,2,4,8 and click OK.
Run the scalability analysis.
You will get the following results:
As expected, time is 8s, regardless of the number of threads used.
You can get the same results if you set the weight of the source_node to 1s and the weight to the function_node to a relatively negligible value. This is because a source_node executes its body serially.