Research On Scheduling Algorithm Of Reconfigurable Computing In Heterogeneous System

Reconfigurable computing technology combines the advantages of general processor and ASIC,not only has high performance and flexibility,but also has low power consumption and high reliability.For typical heterogeneous systems consisting of traditional general processors and reconfigurable computing units,the way operating system manages both resource is one of the key problems of heterogeneous systems.Hardware task scheduling is one of the scheduling problems of operating system,a key factor in obtaining high performance of whole system,and also the hot field of reconfigurable computing.This paper mainly focuses on the scheduling problem of reconfigurable computing in heterogeneous system.The main contributions are outlined as follows:Firstly,this paper analyzes the hardware structure of FPGA and finds out routing resources occupies large chip area.Based on the framework of reconfigurable computing in heterogeneous system,this paper presents a communication structure model with considering the routing resources.This model consists of various communication resources with different data transmission capabilities.Because of communication resource constraints,resource competition occurs when dependency tasks exchange data.To reduce resource competition,this paper proposed a communication coefficient guiding placing dependency tasks more compact onto FPGA to reduce the occupancy of communication bus.Secondly,by analyzing and learning the existing reconfigurable resource management,this paper proposes a resource management strategy which improves the resource management algorithm based on hardware task vertex by partitioning rectangle based on task vertex.This strategy maintains the run-time information of reconfigurable resource by tracking status matrix and partitions maximum free rectangle according to task vertex.Thirdly,based on the existing placement strategy this paper presents a communication-aware maximum adjacent edges strategy which uses adjacent edges as cost function to guide task placement.Abstracting time as the third dimension during scheduling,a communication-aware maximum adjacent surface is proposed and uses adjacent surfaces as cost function to place tasks more compact in 3D model.Finally,a simulation system is designed to implement two-dimensional partial dynamic reconfiguration and verify algorithms by simulating the process of reconfigurable task scheduling.This paper also uses the latest design method of partial dynamic reconfiguration to implement partial reconfiguration in Xilinx development.Experimental results show that the resource management strategy partitioning rectangle based on task vertex works well with allocation strategy based on adjacency.The combination of two strategies place tasks more tightly and improve the scheduling success rate and the utilization of reconfigurable resource of heterogeneous systems.