Directory-based cache coherence is the de-facto standard for scalable shared-memory multi/many-cores and significant effort is invested in reducing its overhead. However, directory area and complexity optimizations are often antithetical to each other.
This talk presents VIPS, a family of cache coherence protocols based on self-invalidation and self-downgrade. VIPS protocols remove the complexity and cost associated with directories in their entirety, thus increasing multiprocessors scalability, and at the same time, provide better performance and energy efficiency than traditional directory-based protocols
