Research On Stream Program Based On Dynamic Rate Edges Task Scheduling And Cache Optimization

The stream programming model has received a great deal of attention in recent years,because it naturally reveals the parallelism of task,data,and pipeline.However,the present situation is that most prior research work is focused on the static scheduling of regular stream programs.For irregular application,that is,there are dynamic input and output rate edges of the application,can not be processed in static scheduling.Scheduling irregular stream programs is very challenging because of the existence of the computing unit is blocking itself due to the lack of data in the input stream and load imbalance,which has become a major hurdle to the scalability of the stream programming model.In order to make the existing stream programming model support irregular stream programs,implemented dynamic scheduling techniques and implemented the cache optimization strategy for dynamic input and output rate edges.The stream programming model divides the COStream source program into multiple static subgraphs with dynamic input and output rate edges.Each static subgraph is exclusive of its own processor core,and then the subgraphs are processed correspondingly and accordingly.For the static subgraphs that do not block,the software pipeline scheduling is used.Otherwise,the method of scheduler is used.The static subgraphs use conditional variables to synchronize operations,avoiding the overhead of using semaphores.Defects for existing dynamic cache policies,such as memory copy overhead.Implemented a new dynamic cache strategy.For shared variables that are frequently accessed,using a lock-free programming to reduce the use of the lock overhead.The C++ multithreaded code is generated based on the result of task scheduling and optimization.The X60 multi-core processor computer is used as the experimental platform to test the COStream compilation system which supports dynamic rate edge,and then the results were analyzed.The experimental results show that the compilation system can support irregular stream program,which increases the scalability of the compilation system and has certain acceleration effect.