The Time Tunnel metaphor allows the user to see a graphical event trace of a parallel code. Processor event time lines are mapped in a circle, with each color representing a certain behavior.
Message passing is represented by edges through the interior of the tunnel.
For MPEG videos illustrating this metaphor, click here . The green represents file reads, while the traces of orange indicate file seeks. This behavior is initiated by a message broadcast to all processors from processor zero, which only some of the processors have currently received. The above picture shows a 32 processor run on an Intel Paragon of an iterative Jocobi code. This code shows an extremely regular behavior with a lot of synchronized message passing.