3.10 User Defined Initial Mapping

You can define the initial mapping of virtual processors (vp) to physical processors (p) as a runtime option. You can choose from predefined initial mappings or define your own mappings. Following predefined mappings are available:

Round Robin

This mapping scheme, maps virtual processor to physical processor in round-robin fashion, i.e. if there are 8 virtual processors and 2 physical processors then virtual processors indexed 0,2,4,6 will be mapped to physical processor 0 and virtual processors indexed 1,3,5,7 will be mapped to physical processor 1.

> ./charmrun ./hello +p2 +vp8 +mapping RR_MAP

Block Mapping

This mapping scheme, maps virtual processors to physical processor in chunks, i.e. if there are 8 virtual processors and 2 physical processors then virtual processors indexed 0,1,2,3 will be mapped to physical processor 0 and virtual processors indexed 4,5,6,7 will be mapped to physical processor 1.

> ./charmrun ./hello +p2 +vp8 +mapping BLOCK_MAP

Proportional Mapping

This scheme takes the processing capability of physical processors into account for mapping virtual processors to physical processors, i.e. if there are 2 processors with different processing power, then number of virtual processors mapped to processors will be in proportion to their processing power.

> ./charmrun ./hello +p2 +vp8 +mapping PROP_MAP
> ./charmrun ./hello +p2 +vp8

If you want to define your own mapping scheme, please contact us for help.