Distributed Scheduling for the Sombrero Single Address Space Distributed Operating System

scheduling, single address space operating systems, operating systems, load balancing Abstract- This paper presents a distributed scheduling algorithm for the Sombrero single address space operating system. This algorithm uses the properties of a single address space and the Sombrero support for thread migration to modify and extend scheduling algorithms developed for multiple address space operating systems to the single address space environment. Threads in the distributed system are scheduled among the different nodes so that CPU usage is balanced. A dynamic local-information-based distributed scheduling algorithm is designed, implemented on a simulation and evaluated. The simulation includes nodes, routers, load tables, and use of them to demonstrate that the distributed scheduling algorithm is correct, works in a single address space distributed shared memory environment and scales in a constant manner with respect to the number of messages and tables required for load balancing. A hierarchical clustering mechanism is used to make the algorithm scale well. The paper also presents, and the simulation includes, the Sombrero fission/merge mechanism for distributing the virtual address space across multiple nodes and the Sombrero use of virtual addresses as an inter-node addressing mechanism. 1