Fast and effective task scheduling in heterogeneous systems

Recently (Proc. ACM Int. Conf. on Supercomput., 1999), we presented two very low-cost approaches to compile-time list scheduling where the tasks´ priorities are computed statically or dynamically. For homogeneous systems, these two algorithms, called FCP (Fast Critical Path) and FLB (Fast Load Balancing), respectively, have been shown to yield a performance equivalent to other much more costly algorithms, such as MCP and ETF (Earliest Task First). In this paper, we present modified versions of FCP and FLB targeted at heterogeneous systems. We show that the modified versions yield a good overall performance, which is generally comparable to algorithms specifically designed for heterogeneous systems, such as HEFT (Heterogeneous Earliest Finish Time) or ERT (which are versions of MCP and ETF, respectively, using the task´s completion time as the task priority). There are a few cases, mainly for irregular problems and large processor speed variance, where FCP´s and FLB´s performances drop to 32% and 63%, respectively. Considering the good overall performance and their very low cost, however, FCP and FLB are interesting options for scheduling very large problems on heterogeneous systems.