Joseph C. Sharp
Abstract
The theory of policy driven schedulers (Ref. [1]) is extended to cover cases in which the scheduling parameters are allowed to adapt dynamically as the system's job load varies. The system under consideration offers batch, time sharing and limited real time services. Data from simulated and live loads are presented to evaluate both the static and the adaptive schedulers.
A policy driven scheduler makes its decisions with respect to a set of policy functions, fi(t). Each of the policy functions corresponds to a different type of user and specifies the amount of computing resources that the system will try to give a user in that group within a given total amount of elapsed time.
It is found that the policy functions must be set conservatively in order to avoid response problems during periods of heavy load, but that during more lightly loaded periods the conservative settings result in widely disparate rates of service to similar jobs. One solution is to vary the policy functions as the job load changes.
A dynamic algorithm is presented that maintains responsiveness during heavy loads and provides fairly uniform service rates at other times.
- 1 Bernstein, A.J., and Sharp, J.C., "A Policy-Driven Scheduler for a Time Sharing System", C.A.C.M., Feb. 1971, p. 74. Google Scholar
Digital Library
- 2 Kerr, R., Bernstein, A., Detlefsen, G. and Johnston, J., "Overview of R & DC Operating System", TIS Report 69-C-355, General Electric, Oct. 1969.Google Scholar
- 3 Ruschitzka, M.G., "System Resource Management in a Time Sharing Environment", PhD Thesis, U.C. Berkeley circa 1973.Google Scholar
- 4 Stimler, Saul, "Some Criteria for Time-Sharing System Performance", C.A.C.M. Jan. 1969, p. 47. Google ScholarDigital Library
Index Terms
- An adaptive policy driven scheduler
Recommendations
An adaptive policy driven scheduler
SIGMETRICS '74: Proceedings of the 1974 ACM SIGMETRICS conference on Measurement and evaluationThe theory of policy driven schedulers (Ref. [1]) is extended to cover cases in which the scheduling parameters are allowed to adapt dynamically as the system's job load varies. The system under consideration offers batch, time sharing and limited real ...
A policy-driven scheduler for a time-sharing system
The services received by a process from a time-sharing operating system can be characterized by a resource count ∑ wiRij where Rij is the number of units of service received by process j from resource i and wi is the cost per unit of the service. Each ...
Adaptive Fair Scheduler: Fairness in Presence of Disturbances
RTNS '16: Proceedings of the 24th International Conference on Real-Time Networks and SystemsThe problem of allocating resources over time to different demands in a "fair" way is present in many application domains. If the resource can be allocated with an arbitrarily fine granularity at no cost, then any type of resource allocation can be ...
Comments