Summary: Modeling Communication Pipeline Latency \Lambda
Randolph Y. Wang y Arvind Krishnamurthy y Richard P. Martin y
Thomas E. Anderson z David E. Culler y
In this paper, we study how to minimize the latency of a
message through a network that consists of a number of
storeandforward stages. This research is especially relevant
for today's low overhead communication systems that em
ploy dedicated processing elements for protocol processing.
We develop an abstract pipeline model that reveals a crucial
performance tradeoff involving the effects of the overhead of
the bottleneck stage and the bandwidth of the remaining
stages. We exploit this tradeoff to develop a suite of frag
mentation algorithms designed to minimize message latency.
We also provide an experimental methodology that enables
the construction of customized pipeline algorithms that can
adapt to the specific system characteristics and application
workloads. By applying this methodology to the Myrinet
GAM system, we have improved its latency by up to 51%.
Our theoretical framework is also applicable to pipelined