This paper presents a software cache coherence scheme that uses virtual memory (VM) support to maintain cache coherency for shared memory multiprocessors and requires no special hardware to do so. Traditional VM translation hardware in each processor is used to detect memory access attempts that would violate cache coherence and system software is used to enforce coherence. The implementation of this class of coherence schemes is extremely economical: it requires neither special multiprocessor hardware nor compiler support, and easily incorporates different consistency models. We evaluated two consistency models for the VM-based approach: sequential consistency and lazy release consistency. The VM-based schemes are compared with a bus based snoopy caching architecture, and our trace-driven simulation results show that the VM-based cache coherence schemes are practical for small-scale, shared memory multiprocessors. Keywords: shared memory, multiprocessors, cache coherence, memory manag...

: Virtual memory based cache coherence is a mechanism that relies only on hardware that already exists on the microprocessors of a shared memory multiprocessor system, yet dynamically detects and resolves potential cache inconsistencies using virtualmemory techniques. The key feature of the approach is that the virtual memory translation hardware on each processor is used to detect shared accesses that could lead to memory incoherencies, and VM page fault handlers execute the appropriate actions to maintain cache coherence. VM-based cache coherence basically trades off design simplicity against increased software overheads. The work presented in this paper evaluates this tradeoff. We show that VM-based cache coherence performs well for scientific applications that require significant aggregate memory bandwidth. ffl Keywords: shared memory, multiprocessors, cache coherence, virtual memory, performance evaluation. ffl Biographies: Karin Petersen is a Member of the Research Staff at Xe...

This paper presents an evaluation of a new class of software cache coherence schemes that use virtual memory (VM) support to maintain multiprocessor cache coherence. Traditional VM translation hardware in each processor detects memory access attempts that would violate cache coherence and system software is used to enforce coherence. The implementation of this class of coherence schemes is extremely economical: it requires neither special multiprocessor hardware nor compiler support, and easily incorporates different consistency models. We have evaluated four consistency models for the VM-based approach: sequential consistency, singlewriter release consistency, release consistency, and lazy release consistency. Our trace-driven simulation results show that the VM-based cache coherence schemes are practical for small-scale multiprocessors and that the performance of lazy release consistency for multi-threaded parallel programs is close to the snoopy-cache invalidation-based coherence ap...