TR-97-4.ps.Z


X. Du, Y. Dong and X. Zhang  
"Effectively scheduling parallel tasks and communications on 
networks of workstations" 

Proceedings of Euro-Par'97, August 1997, pp. 887-894. 
 
Abstract
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Coordinating parallel tasks and minimizing communication delays are 
two important issues for design of scheduling policies on networks 
of workstations. We address the two issues by presenting a scheduling 
scheme which consists of two parts: computation scheduling and 
communication scheduling. The computation scheduler on each workstation 
schedules its parallel task and local user jobs independently based 
on a static power preservation in that workstation so that parallel 
tasks on different workstations are executed at the same pace to 
achieve a global coordination. To minimize communication latency, each 
local scheduler uses a non-preemptive strategy to try to make 
communication activities complete as soon as possible. The scheduling 
scheme is evaluated by simulating the execution of four NAS benchmark 
programs, and comparing it with a Unix-based scheduling policy and the 
co-scheduling policy. Our experiments show that the power preservation 
in each workstation guarantees the performance of both parallel 
and local jobs. Furthermore, the communication delay is reduced 
significantly by the communication scheduling compared with a 
spinning based scheme and a Unix based scheme.