
Lossless networks, such as InfiniBand use flow-control to avoid packet-loss due to congestion. This introduces dependencies between input and output channels, in case of cyclic dependencies the network can deadlock. Deadlocks can be resolved by splitting a physical channel into multiple virtual channels with independent buffers and credit systems. Currently available routing engines for InfiniBand assign entire paths from source to destination nodes to different virtual channels. However, InfiniBand allows changing the virtual channel at every switch. We developed fast routing engines which make use of that fact and map individual hops to virtual channels. Our algorithm imposes a total order on virtual channels and increments the virtual channel at every hop, thus the diameter of the network is an upper bound for the required number of virtual channels. We integrated this algorithm into the InfiniBand software stack. Our algorithms provide deadlock free routing on state-of-the-art low-diameter topologies, using fewer virtual channels than currently available practical approaches, while being faster by a factor of four on large networks. Since low-diameter topologies are common among the largest supercomputers in the world, to provide deadlock-free routing for such systems is very important.
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 9 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
