# Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment

@article{Liu1973SchedulingAF, title={Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment}, author={Chung Laung Liu and James W. Layland}, journal={J. ACM}, year={1973}, volume={20}, pages={46-61} }

The problem of multiprogram scheduling on a single processor is studied from the viewpoint of the characteristics peculiar to the program functions that need guaranteed service. It is shown that an optimum fixed priority scheduler possesses an upper bound to processor utilization which may be as low as 70 percent for large task sets. It is also shown that full processor utilization can be achieved by dynamically assigning priorities on the basis of their current deadlines. A combination of… Expand

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#### References

SHOWING 1-10 OF 24 REFERENCES

Preemptive Scheduling of Real-Time Tasks on Multiprocessor Systems

- Computer Science
- JACM
- 1970

The authors solve the problem of scheduling a set of tasks whose operational precedence structure is representable as an acyclic directed graph and proof of an efficient algori thm for finding the minimal-length preemptive schedule for tree-structured computations. Expand

Multiprogram scheduling: parts 1 and 2. introduction and theory

- Computer Science
- CACM
- 1960

A concise scheduling algorithm is described which tends to minimize the time for executing the entire pending workload (or any subset of it), subject to external constraints such as precedence, urgency, etc. Expand

Production and Stabilization of Real-Time Task Schedules

- Computer Science
- JACM
- 1967

A coherent theory of task-list control is developed, in which the nature of peculiarities of this control scheme is brought under systematic study and a number of potentially useful results are derived. Expand

A scheduling philosophy for multiprocessing systems

- Computer Science
- CACM
- 1968

A collection of basic ideas is presented, which have been involved by various workers over the past four years to provide a suitable framework for the design and analysis of multiprocessing systems.… Expand

Multiprogram scheduling: parts 3 and 4. scheduling algorithm and external constraints

- Computer Science
- CACM
- 1960

The scheduling algorithm examines the programs to be scheduled one by one and places their component rectangles in the corresponding load diagrams according to a set of placement rules.

Sequencing Aspects of Multiprogramming

- Computer Science
- JACM
- 1961

The sequencing or scheduling aspects of multiprogramming are discussed, which have not been studied in mathematical detail in the machine shop scheduling context, but have been discussed under the name of job-lot MSS. Expand

A Survey of Analytical Time-Sharing Models

- Computer Science
- CSUR
- 1969

The parameters which are considered in the different analytic models provide the system designer with a number of degrees of freedom with which to synthesize a t]me-shared processing system and point out needed research directions. Expand

Bounds for certain multiprocessing anomalies

- Computer Science, Mathematics
- 1966

It is known that in multiprocessing systems composed of many identical processing units operating in parallel, certain timing anomalies may occur; e.g., an increase in the number of processing units… Expand

A policy-driven scheduler for a time-sharing system

- Computer Science
- CACM
- 1971

The algorithm has been implemented in a general purpose operating system, and it has provided significantly better service to interactive and to batch jobs than the previous scheduler. Expand

Certification of Algorithm 46: Exponential of a complex number

- Computer Science
- Commun. ACM
- 1962

The procedure was originally programmed in FORTRAN for the Control Data 160 desk-size computer and was limited to te t ra t ion because subroutine recursiveness in CONTROL Data 160 FORTRan has been held down to four levels in the interests of economy. Expand