The complexity of verifying memory coherence and consistency

摘要

The problem of testing shared memories for memory coherence and consistency is studied. First, it is proved that detecting violations of coherence in an execution is NP-complete, and it remains NP-complete for a number of restricted instances. This result leads to a proof that all known consistency models are NP-hard to verify. The complexity of verifying consistency models is not a mere consequence of coherence, and verifying sequential consistency remains NP-complete even after coherence has been verified.