Improving throughput and utilization in parallel machines through concurrent gang

In this paper we propose a new class of scheduling policies, dubbed Concurrent Gang, that combines the advantages of gang scheduling for communication and synchronization intensive parallel jobs with the flexibility of a Unix scheduler for sequential and I/O intensive jobs. Besides that, scalability in Concurrent Gang is achieved through the use of a global synchronizer that coordinates the gang scheduler among different processors. Simulation results are provided comparing the performance of Concurrent Gang with Gang Scheduling and show significant performance improvements, in particular for I/O bound jobs