AN EXECUTION SLEEP SCHEDULING POLICY FOR SERVING AN ADDITIONAL JOB IN PRIORITY QUEUING-SYSTEMS
In a priority-based computer system, besides the regular jobs, an additional job (referred to as job A) is invoked infrequently but requires a significant amount of CPU time. To avoid CPU hogging, job A receives (up to) a fixed amount of CPU time whenever it is served. When the time expires, job A immediately relinquishes the CPU and puts itself to sleep for a period of time. By doing so, jobs with low priority may be processed in a timely manner. When the sleep time is over, job A is awakened and waits to resume service according to its priority. Then, the whole process is repeated until job A service is completed. In this paper, such an execution/sleep (ES) scheduling policy is analyzed for serving job A in a nonpreemptive priority queuing system. The Laplace Transforms are derived for: (i) the conditional response time of job A and (ii) the response time for jobs with priorities higher and lower than job A. This work is motivated by the use of the ES policy in a switching system in which job A is invoked in response to the failure of signaling links. The proposed model is applicable to other real-time computer systems, and the modeling techniques can be applied or generalized to analyzing other scheduling policies in which timers are involved.
response times performance theory performance evaluation priority queues server vacation models time-limited service waiting times