Contention free pipelined broadcasting within a constant bisection bandwidth network topology

A method for pipelined broadcasting within an interconnection network, comprising:

• connecting communicatively a plurality of nodes each of which comprises at least one adapter through an interconnection network comprising a first plurality of switches, wherein each of the plurality of nodes is connected to one of the first plurality of switches and wherein each of the first plurality of switches is connected through a second plurality of switches, wherein each of the plurality of nodes is connected through a plurality of shared links connecting the first plurality of switches and the second plurality of switches;
• and
• scheduling, using a processor, a hierarchical pipelined broadcast through at least one switch of the first plurality of switches from among a plurality of non-root nodes by:
• selecting, using the processor, two nodes of the plurality of non-root nodes connected to the at least one switch;
• and
• scheduling, using the processor, each of a plurality of broadcast steps for the pipelined broadcast with at least one of an inter-switch broadcast phase with a first node of the two nodes receiving a first data packet from another switch from among the first plurality of switches and a second node of the two nodes sending a second data packet previously received from the another switch to one other switch from among the plurality of switches and an intra-switch broadcast phase with the first node acting as a source for sending a previously received data packet to at least one other non-root node and the second node acting as a sink for receiving the previously received data packet, wherein each of the non-root nodes sends and receives the previously received data packet once throughout the plurality of broadcast steps and the sink receives the previously received data packet last, wherein for each next step of the plurality of broadcast steps the first node and the second node alternate roles.

A computer program product for pipelined broadcasting within an interconnection network, the computer program product comprising:

• one or more computer-readable, tangible storage devices;
• program instructions, stored on at least one of the one or more storage devices, to connect communicatively a plurality of nodes each of which comprises at least one adapter through an interconnection network comprising a first plurality of switches, wherein each of the plurality of nodes is connected to one of the first plurality of switches and wherein each of the first plurality of switches is connected through a second plurality of switches, wherein each of the plurality of nodes is connected through a plurality of shared links connecting the first plurality of switches and the second plurality of switches;
• and
• program instructions, stored on at least one of the one or more storage devices, to schedule a hierarchical pipelined broadcast through at least one switch of the first plurality of switches from among a plurality of non-root nodes by selecting two nodes of the plurality of non-root nodes connected to the at least one switch and scheduling, using the processor, each of a plurality of broadcast steps for the pipelined broadcast with at least one of an inter-switch broadcast phase with a first node of the two nodes receiving a first data packet from another switch from among the first plurality of switches and a second node of the two nodes sending a second data packet previously received from the another switch to one other switch from among the plurality of switches and an intra-switch broadcast phase with the first node acting as a source for sending a previously received data packet to at least one other non-root node and the second node acting as a sink for receiving the previously received data packet, wherein each of the non-root nodes sends and receives the previously received data packet once throughout the plurality of broadcast steps and the sink receives the previously received data packet last, wherein for each next step of the plurality of broadcast steps the first node and the second node alternate roles.