FeatherWeight: Low-cost optical arbitration with QoS support

Yan Pan*, John Kim, Gokhan Memik

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

29 Scopus citations


The nanophotonic signaling technology enables efficient global communication and low-diameter networks such as crossbars that are often optically arbitrated. However, existing optical arbitration schemes incur costly overheads (e.g., waveguides, laser power, etc.) to avoid starvation caused by their inherent fixed priority, which limits their applicability in power-bounded future many-core processors. On the other hand, quality-of-service (QoS) support in the on-chip network is becoming necessary due to an increase in the number of components in the network. Most prior work on QoS in on-chip networks has focused on conventional multi-hop electrical networks, where the efficiency of QoS is hindered by the limited capabilities of electrical global communication. In this work, we exploit the benefits of nanophotonics to build a lightweight optical arbitration scheme, FeatherWeight, with QoS support. Leveraging the efficient global communication, we devise a feedback-controlled, adaptive source throttling scheme to asymptotically approach weighted max-min fairness among all the nodes on the chip. By re-using existing datapath components to exchange minimal global information, FeatherWeight provides freedom from starvation while resulting in negligible (< 1%) throughput loss compared to the best-effort baseline optical arbitration. In addition, FeatherWeight provides strong fairness, performance isolation, and differentiated service for a wide range of traffic patterns. Compared to state-of-art optical arbitration schemes, FeatherWeight reduces power consumption by up to 87% while reducing execution time by 7.5%, on average, across SPLASH-2 and MineBench traces, and improving throughput on synthetic traffic patterns by up to 17%.

Original languageEnglish (US)
Title of host publicationMICRO 44 - Proceedings of the 44th Annual IEEE/ACM Symposium on Microarchitecture
Number of pages12
StatePublished - 2011
Event44th Annual IEEE/ACM Symposium on Microarchitecture, MICRO 44 - Porto Alegre, RS, Brazil
Duration: Dec 4 2011Dec 7 2011

Publication series

NameProceedings of the Annual International Symposium on Microarchitecture, MICRO
ISSN (Print)1072-4451


Other44th Annual IEEE/ACM Symposium on Microarchitecture, MICRO 44
CityPorto Alegre, RS


  • arbitration
  • interconnection networks
  • nanophotonics

ASJC Scopus subject areas

  • Hardware and Architecture


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