The Dynamic Load Balancing of Clustered Time Warp for Logic Simulation

Abstract

We present, in this paper, a dynamic load balancing aJ.gorit.hm developed for Clustered Time Warp, a hybrid approach which makes we of Time Warp bet.wwn clusters of LPs and a sequent.isl mechanism within the clusters. The load balancing algorithm focuses on distributing the load of the sirnnlat.ion evenly among the processors and then tries to reduce interprocesmr communicatiorw We make nse of a triggering techniqne based on the thronghpnt of the sinmlat.ion system. The algorithm was implemented and its performance W-M rneasnred usin two of the largest 8 benchmark digital circnits of the I CAS’89 series. In order t,o measnre the effects of the algorithm on worklm.d distribution, inter-proces..or communication and rollbacks, we defined three dktinct met rim. Results show that by dynamicaJ1y balancing the load, the throughput was improved by 40 to 100% when compared to Time Warp. Thrcmghpnt. is the nnmbw of non rolled-back message events per unit time. It’hen the algorithm tried to reduce inter-processor communication, rollbacks were substantially rwlnced. Nevertheless, no substantial improvement was observed on the overall simulation time, sng Ming that f load distribution is the most important actor to be taken into consideration in speeding up the simulation of d@jt.ai circuits.