This work proposes a novel scheme to facilitate heterogeneous systems with unified virtual memory. Research proposals implement coherence protocols for sequential consistency (SC) between central processing unit (CPU) cores and between devices. Such mechanisms introduce severe bottlenecks in the system; therefore, we adopt the heterogeneous-race-free (HRF) memory model. The use of HRF simplifies the coherency protocol and the graphics processing unit (GPU) memory management unit (MMU). Our protocol optimizes CPU and GPU demands separately, with the GPU part being simpler while the CPU is more elaborate and latency aware. We achieve an average 45p speedup and 45p energy-delay product reduction (20p energy) over the corresponding SC implementation.
['Konstantinos Koukos', 'Alberto Ros', 'Erik Hagersten', 'Stefanos Kaxiras']
Building Heterogeneous Unified Virtual Memories (UVMs) without the Overhead