EST Estimation and Tasks Scheduling Based on Expanded Stochastic DAG

Considering the fact that the EST value in scheduling DAG is composed of the means of computation and communication time,some researches on parallel tasks scheduling algorithms are done while one typical algorithm ETF is analyzed,and SETF algorithms for the expanded stochastic DAG is presented correspondingly.Then a method to compute the nodes’ EST is provided.And experiments are done to simulate it.Experimental results indicate that a significant improvement in the average parallel execution times of expanded stochastic DAG can be achieved by the proposed approaches and it is able to more accurately predict the actual performance than the algorithms ETF.