LazyPIM: An Efficient Cache Coherence Mechanism for Processing-in-Memory

  • Amirali Boroumand ,
  • Saugata Ghose ,
  • Minesh Patel ,
  • Hasan Hassan ,
  • Brandon Lucia ,
  • ,
  • Krishna T. Malladi ,
  • Hongzhong Zheng ,
  • Onur Mutlu

IEEE Computer Architecture Letters (CAL) | , Vol 16(1)

Processing-in-memory (PIM) architectures cannot use traditional approaches to cache coherence due to the high off-chip traffic consumed by coherence messages. We propose LazyPIM, a new hardware cache coherence mechanism designed specifically for PIM. LazyPIM uses a combination of speculative cache coherence and compressed coherence signatures to greatly reduce the overhead of keeping PIM coherent with the processor. We find that LazyPIM improves average performance across a range of PIM applications by 49.1% over the best prior approach, coming within 5.5% of an ideal PIM mechanism.