sues in Implementing Sequential Consistency IPPPPIPI M 现代计算机系统实现SC的两个问题 Out-of-order execution capability oad(a; Load(b) yes Load(a): store(b) yes if a* b Store(a; Load(b yes if a* b Store(a: store(b) yes if a* b o Caches, write buffer Cache使得某一处理器的 store操作不能被另一处理器即时看到 No common commercial architecture has a sequentially consistent memory model!!! 2021/2/11 计算机体系结构 8Issues in Implementing Sequential Consistency 8 现代计算机系统实现SC 的两个问题 • Out-of-order execution capability Load(a); Load(b) yes Load(a); Store(b) yes if a  b Store(a); Load(b) yes if a  b Store(a); Store(b) yes if a  b • Caches. Write buffer Cache使得某一处理器的store操作不能被另一处理器即时看到 M P P P P P P No common commercial architecture has a sequentially consistent memory model ！！！ 2021/2/11 计算机体系结构