• Blesscc++ keep track of injection of all nodes: scalability solutions
  • keep track of highest (how?)
  • random sampling
  • per region injection rate (hierarchically)

• Michael: Inline feedback more ideal
  • give reflected packets dedicated virtual channel
  • Onur: feeling that it has limited effectiveness compared to backchannel
  • highest priorty might work
  • can eliminate starvation
  • must resend reflected flits

• Link-monitoring
  • keep track of congestion over n>1 cycles
  • at every cycle may be unfair
  • very local view of network
  • just looking at k is conservative, not efficient
  • investigate whether k can depend on MTTS values/deflection rates
    • case where every link in use but no deflections
    • k depends on network location, neighbors
    • k can be congestion predictor, large problem space to explore

1. duato regional congestion notification / bluegene
2. router knows local and onehop deflection rates
3. back network signaling: starvation response granularity
4. distinguish between starvation freedom and congestion control
   • target starvation freedom first
   • progress to congestion control for performance, fairness, latency, bandwidth
5. congestion: how to detect, when signal, who signaled
   • once detected: how to throttle, when, who to throttle, how long to throttle
6. feedback on throttling decisions? back back network?

Back to Project Page