- 2dmesh: organizes the nodes as a two dimensional mesh, and perform allgather
along the dimensions
- 3dmesh: adds a third dimension to the previous algorithm
- - rdb: recursive doubling : extends the mesh to a nth dimension, each one
+ - rdb: recursive doubling: extends the mesh to a nth dimension, each one
containing two nodes
- pair: pairwise exchange, only works for power of 2 procs, size-1 steps,
each process sends and receives from the same process at each step
