Research On Communication-and-Thermal-aware Task Mapping Algorithm In Network-on-Chip System

As application performance demands continue to grow and chip integration increases,many-core systems are widely used in servers,data centers,clusters,and other systems to provide high-throughput computing services.Task mapping refers to the selection of running cores for an application.Task mapping process has a critical impact on system performance.With the rapid development of integrated circuit technology,the power density of the chip increases accordingly.Temperature has become an important constraint in many-core system.In systems like servers,CPU utilization is often less than 100%.In such systems,power density can be reduced by placing power-off cores around a working core.How to allocate these closed cores under thermal constraint to improve system performance become a challenge.In addition,the 3D many-core system has become the trend of many-core chips due to its higher integration.However,high integration leads to more prominent temperature problems on 3D many-core systems.The characteristics that differ 3D many-core system from 2D manycore system are: the vertical link in 3D many-core system has a shorter communication distance,and its power densities of each layer are different.The layer closer to the heat sink can work on a higher frequency.How to utilize the vertical link and the cores close to heat sink in the3 D integrated many-core system becomes a difficult task in the task mapping process of the 3D many-core system.Applications have different performance demands: some have greater communication demand,while others have larger computing demand.Based on this observation,following researches are carried out: 1)proposed a task mapping algorithm allocating power-off cores for each application under temperature constraints to optimize system throughput.Experiments showed that compared with the two existing algorithms,the proposed algorithm could increase system throughput by up to 50%.2)proposed a task mapping algorithm for 3D many-core system that characterizes the shape of each mapping core region.Experiments showed that compared with two existing algorithms,the proposed algorithm could reduce application running time by 48% 3)Designed and implemented a task mapping visualization tool to help algorithm designers to verify,optimize and select task mapping algorithms.