A study of response times under various deadlock algorithms and job schedulers

Abstract

A trace-driven model is used to study the effects of various schedulers and deadlock control algorithms, and their interactions, on response times in a general-purpose operating system. Jobs' requests for memory and processors are extracted from a production load and used to drive a detailed simulation program. The simulation results show that response time is more sensitive than CPU utilization to differences between schedulers and deadlock control algorithms. Preemptive scheduling improves response time but degrades CPU utilization. Preemptive deadlock control algorithms improve both measures of performance. There are significant interactions between schedulers and deadlock control algorithms. Deadlock control algorithms can not be expected to optimize resource utilization.