Useful things to know about mapping assignments:

  1. You can specify parallel assignments. For example, suppose you want a specific task to be mapped in parallel to three computers. Simply name them in the list, for example: PE1 PE2 PE3. And making the Produce amount three times the Threshold amount implies three parallel tasks will be ready to run when the previous node fires.

  2. You can specify sequences of parallel mappings. Suppose you want a specific task to be mapped in parallel first to three computers, next to three others, and then back again to the first three, and so on. Simply name them in the list: PE1 PE2 P3   PE4 PE5 PE6   PE7 PE8 PE9. The list will repeat in a round-robin fashion, each time the sequence is exhausted.

  3. You can specify First-Available-From-a-Group mappings. That is, you can designate a group of processors that a set of tasks will map to. But not any specific order. To do this, set the task node type to be GetAny, then list the processors.

  4. You can specify groups of processors as macros. This is especially handy when mapping large sections of DFG's (many nodes) to various groups. This way, you need only change one definition to alter the mapping of many tasks.

  5. Task groupings can be heirarchical. This provides very rapid remapping of your DFG's. For example, you can define subgroup1 = PE1 PE2, and subgroup2 = PE3 PE4, through subgroup40, etc.. If you define GroupA to be the subgroups from 1-9, and GroupB to be the subgroups from 10-19, then you can conveniently map a highly parallel task to many processors by simply mapping it to GroupA GroupB. Etc..

Note: If using the actual device names in the mapping list, the devices must be spelled exactly as listed in the netinfo file, - they must begin with a forward slash (/). The above assumes macros PExx for the actual names were used. (Often a good idea.) Alternately, the Scheduler can be used without a netinfo file by giving the total number of processors to consider on the Scheduler's command-line with the -n option, and without giving a netinfo file. In this case, (as well as with a netinfo file), the processor logical ID numbers can be used in mapping assignment lists, beginning with 0.