CSC/ECE 506 Spring 2012/11a hn

Distributed Shared Memory

In a Distributed Shared Memory (DSM) several processors share the same address space but unlike the shared memory system they do not actually use a global memory which is accessible by all processors, instead it is a logical abstraction of a single address space for different memory locations which can be accessed by all processors.

Illustration of Shared memory system ^[1].

Instead of implementing shared memory model with a bus support the DSM uses a more scalable and less expensive model by supporting the abstraction of shared memory by using message passing. The main memory of a cluster of processors is made to look like a single memory with a single address space. The DSM allows the programmer to share and use variables without having to worry about their management. Hence a processor can access a address space held by other processors main memory. The DSM allows end-users to use the shared memory without knowing the message passing,the idea is to allow inter processor communication which is invisible to the user.

Performance Improvement

References

1. Distributed Shared Memory Systems