缓存一致性问题研究

以共享总线的多处理机系统为例，介绍了在共享总线系统中用于解决Cache Coherence问题的监听总线协议（Snoopy Protocol）和写一次协议（Write-Once Protocol），并分析了写一次协议、一致性协议的优点和协议区分状态的原因，最后给出一个评价协议好坏的角度：总线的流量和存储器访问的有效时间。

Research on the Problem of the Cache Coherence

Taking the multi-processor system of the common bus as the example, this paper introduces the Snoopy Protocol and the Write-Once Protocol used for solving the problem of Cache Coherence in the common bus system, analyzes on the advantages of the Write-Once Protocol and the Coherence Protocol and on the causes of the separating state of the protocols, and gives an angle for evaluating the good or bad of a protocol: the flow of the bus and the valid time of the access of the memory.