This is an old revision of the document!

Tony's M2 Meeting Minutes

  • 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
Other Points
  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?

Personal Tools