All-to-All Broadcast in Dragonfly Networks

New deadlock-free unicast-based all-to-all broadcast algorithms are proposed for dragonfly networks. An all-to-all broadcast delivers a message from each router to all routers. Two different all-to-all broadcast algorithms GFA2A and RFA2A using the previous group-first and router-first one-to-all broadcast schemes are presented. A new all-toall broadcast algorithm named A2A is presented by collecting all messages from all routers in the same group to a single router first and combining them, which are forwarded to all routers in the same group. Each router forwards messages to all other routers in the same groups after receiving all messages from other groups. The proposed algorithms can be implemented with the unicast hardware, that is, each input port is assigned two indistinguishable buffers.