TARDIS: Timestamp based Coherence Algorithm for Distributed Shared Memory

A new memory coherence protocol, TARDIS, is proposed. TARDIS uses timestamp counters representing logical as opposed to physical time to order memory operations and enforce memory consistency models in any type of shared memory system. Compared to the widely-adopted directory coherence protocol, TARDIS is simpler, only requires O(log N ) storage per cache block for an N-core system rather than the O(N) sharer information required by conventional directory protocols, and integrates better with some system optimizations. On average, TARDIS achieves similar performance to directory protocols on a wide range of benchmarks.