Analysis of cycle stealing with switching times and thresholds

We consider two processors, each serving its own M/GI/1 queue, where one of the processors (the “donor”) can help the other processor (the “beneficiary”) with its jobs, during times when the donor processor is idle. That is the beneficiary processor “steals idle cycles” from the donor processor. There is a switching time required for the donor processor to start working on the beneficiary jobs, as well as a switching back time. We also allow for threshold constraints on both the beneficiary and donor sides, whereby the decision to help is based not only on idleness but also on satisfying threshold criteria in the number of jobs. We analyze the mean response time for the donor and beneficiary processors. Our analysis is approximate, but can be made as accurate as desired, and is validated via simulation. Results of the analysis illuminate principles on the general benefits of cycle stealing and the design of cycle stealing policies.