Parallel Configurations

SYMPHONY supports numerous configurations, ranging from completely sequential to fully parallel, allowing efficient execution in many different computational settings. As described in the previous section, there are five modules in the standard distributed configuration. Various subsets of these modules can be combined to form separate executables capable of communicating with each other across a network. When two or more modules are combined, they simply communicate through shared-memory instead of through message-passing. However, they are also forced to run in sequential fashion in this case, unless the user chooses to enable threading using an OpenMP compliant compiler (see next section).

As an example, the default distributed configuration includes a separate executable for each module type, allowing full parallelism. However, if cut generation is fast and not memory-intensive, it may not be worthwhile to have the NP module and its associated cut generator work independently, as this increases communication overhead without much potential benefit. In this case, the cut generator functions can be called directly from the NP module, creating a single, more efficient executable.



Ted Ralphs
2010-03-24