Symbiotic Jobscheduling for a Simultaneous Multithreading Processor

Simultaneous Multithreading machines fetch and execute instructions from multiple instruction streams to increase system utilization and speedup the execution of jobs. When there are more jobs in the system than there is hardware to support simultaneous execution, the operating system scheduler must choose the set of jobs to coschedule This paper demonstrates that performance on a hardware multithreaded processor is sensitive to the set of jobs that are coscheduled bythe operating systemjobscheduler. Thus, the full bene ts of SMT hardware can only be achieved if the scheduler is aware of thread interactions. Here, a mechanism is presented that allows the scheduler to signi cantly raise the performance of SMT architectures. This is done without any advance knowledge of a workload's characteristics, using sampling to identify jobs which run well together. We demonstrate an SMT jobscheduler called SOS. SOS combines an overhead-free sample phase which collects information about vario...

• Type: Conference
• Year: 2000
• Where: ASPLOS
• Authors: Allan Snavely, Dean M. Tullsen
• Keywords: ASPLOS 2000, Hardware Multithreaded Processor, Multiple Instruction Streams, Programming Languages, Simultaneous Multithreading Machines