Efficient and Scalable Synchronization via Generalized Cache Coherence

Abstract

Existing synchronization primitives scale poorly on disaggregated shared memory because they introduce redundant inter-cache communication over high-latency links. This work observes that synchronization generalizes cache coherence in time and space and minimally extends coherence protocols to support synchronization directly. Its Generalized cache-Coherence Protocol uses wait queues and variable-size cache lines for the temporal and spatial generalizations and is verified with model checking. Soul implements the protocol end to end and supports popular lock APIs without application changes. Against state-of-the-art locks, Soul improves unmodified real-world application performance at scale by one to two orders of magnitude with under 8 percent storage overhead.

BibTeX

@inproceedings{soul,
  title = {{Efficient and Scalable Synchronization via Generalized Cache Coherence}},
  author = {Yu, Yanpeng and Lee, Seung-seob and Zhong, Lin and Khandelwal, Anurag},
  month = jul,
  booktitle = {USENIX OSDI},
  year = {2026}
}