DynMap: A Heuristic Dynamic Mapper for CGRA Multitask Dynamic Resource Allocation

Coarse-grained reconfigurable architecture (CGRA) has received increasing attention in both industry and academia due to its comprehensive advantages of performance, energy efficiency, and flexibility. To improve the resource utilization and handle the mixing workloads in the real-world, multiple tasks sharing the whole CGRA has became an important technical trend, and the varying resource requirements throughout their life cycles also makes run-time dynamic resource allocation (DRA) necessary for higher-multitask throughput. As the key stage of DRA, dynamic mapping (DM) is responsible for mapping kernels within each task to the dynamically allocated CGRA resources. However, existing DM methods have difficulty to balance the mapping time and the mapping quality, resulting in a significant gap between the actual and the optimal task throughput. To address the challenge, we propose DynMap, a heuristic dynamic mapper for CGRA multitask DRA. With the support of specialized scheduling and routing schemes, DynMap heuristically references the placement tendency in the static mapping result to dramatically save the mapping time, while maintaining the high-mapping quality by minimizing the possibility of resource conflicts. Experimental evaluation demonstrates DynMap not only achieves the average 1.17 ms mapping time and average 98.33% of the optimal mapping quality on different CGRA architectures, but also reaches average 98.85% of the optimal task throughput expected by different CGRA multitask DRA scenarios, reducing the gap between actual and optimal task throughput average $31.75\times $ smaller than that of the current methods.