vPIM: Efficient Virtual Address Translation for Scalable Processing-in-Memory Architectures.

3D-stacked memory technologies make it possible to integrate computation logic into the memory stack to reduce data movement between CPU and memory, enabling processing-in-memory (PIM). PIM systems scale in capacity and bandwidth by connecting multiple PIM stacks through a memory network. They also need to be programmable, where having virtual memory support is critical. Existing address translation schemes, however, are not optimized for a scalable PIM system. In this work, we propose VPIM, a virtual address translation scheme for scalable, multi-stack PIM systems. VPIM optimizes contention of the memory network in a PIM system and reduces translation time with pre-translation. Our evaluation shows a speedup of 4.4x and 1.7x compared to conventional radix and cuckoo hash page tables in eight memory-intensive workloads.