优化迁移共享的自适应令牌协议

An Adaptive Token Protocol Optimized for Migratory Sharing

针对写作废的一致性协议在处理迁移特征时需要2次访问的特征,提出了一种自适应的令牌协议,根据数据的读/写处理器和数据的令牌信息判断数据是否具有迁移特征.如果数据具有迁移特征,则请求者的状态变为可以避免迁移访问序列中出现写访问的状态MG,从而消除了迁移特征中的写作废次数.结果表明,所提出的自适应令牌协议在读访问时获取了数据所有权,避免了部分写失效的产生,从而使得平均失效延迟降低5%,通信量平均降低9%.

According to the migratory pattern means that the accessing processor initiates two separate requests to obtain first read and then write permission in invalidation-based protocol, this paper proposed adaptive protocol which uses the token number and the writer or reader of data to recognize the migratory pattern. While the data is in migratory pattern, the requestor＇s state changes to MG state which can avoid the write request in migratory access. It effectively eliminates invalidation in migratory pattern. The adap- tive protocol gets the ownership when reading the sharing data, and thus avoids some write misses. The results show that the adaptive protocol reduces the miss latency by an average of 5%, and the network traffic by an average of 9 %.