- 期刊
- OpenAccess
Design and Implementation of Cohesion
並列摘要
This paper describes a prototype DSM system called Cohesion which sup ports two memory consistency models, namely, Sequential consistency and Release consistency, within a single program to improve performance and support a wide variety of parallel programs for the system. Memory that is sequentially consistent is further divided into object based and conventional (page based) memory, where they are constructed at the user level and kernel level, respectively. In object based memory, the shared data are kept consistent in terms of the granularity of an object: this is provided to improve the performance of fine grained parallel applications that may incur a significant overhead in conventional or release memory as well as to eliminate unnecessary movement of pages which are protected in a critical section. On the other hand, the Release consistency model is supported in Cohesion to attack the problem of excessive network traffic and false sharing. Cohesion programs are written in C++, and the annotation of shared objects for release and object based memory is accomplished by inheriting a system provided base class. Cohesion is built up on a network of Intel 486-33 personal computers which are connected by a 10Mbps Ethernet. Three application programs, including Matrix Multiplication, SOR, and N body, have been employed to evaluate the efficiency of Cohesion. In addition, a Producer Consumer program has been tested to show that the object based memory will benefit us in a critical section.