The design of the UNIX operating system
The design of the UNIX operating system
Introduction to algorithms
Theoretical Computer Science - Special issue on dynamic and on-line algorithms
Approximating total flow time on parallel machines
STOC '97 Proceedings of the twenty-ninth annual ACM symposium on Theory of computing
Online computation and competitive analysis
Online computation and competitive analysis
Speed is as powerful as clairvoyance
Journal of the ACM (JACM)
Theoretical Computer Science - Selected papers in honor of Manuel Blum
Scheduling Algorithms
Operating Systems Theory
Operating Systems
Operating System Concepts
Competitive Analysis of the Round Robin Algorithm
ISAAC '92 Proceedings of the Third International Symposium on Algorithms and Computation
Developments from a June 1996 seminar on Online algorithms: the state of the art
Speed is more powerful than clairvoyance
Nordic Journal of Computing
Utilization of nonclairvoyant online schedules
Theoretical Computer Science
Competitive online scheduling for server systems
ACM SIGMETRICS Performance Evaluation Review
Average-Case and Smoothed Competitive Analysis of the Multilevel Feedback Algorithm
Mathematics of Operations Research
Approximating total flow time on parallel machines
Journal of Computer and System Sciences
ACM Transactions on Algorithms (TALG)
An Optimal Strategy for Online Non-uniform Length Order Scheduling
AAIM '08 Proceedings of the 4th international conference on Algorithmic Aspects in Information and Management
Scalably scheduling processes with arbitrary speedup curves
SODA '09 Proceedings of the twentieth Annual ACM-SIAM Symposium on Discrete Algorithms
Speed scaling of processes with arbitrary speedup curves on a multiprocessor
Proceedings of the twenty-first annual symposium on Parallelism in algorithms and architectures
Improved results for scheduling batched parallel jobs by using a generalized analysis framework
Journal of Parallel and Distributed Computing
Provably efficient two-level adaptive scheduling
JSSPP'06 Proceedings of the 12th international conference on Job scheduling strategies for parallel processing
Scheduling jobs with varying parallelizability to reduce variance
Proceedings of the twenty-second annual ACM symposium on Parallelism in algorithms and architectures
Non-clairvoyant scheduling for weighted flow time and energy on speed bounded processors
CATS '10 Proceedings of the Sixteenth Symposium on Computing: the Australasian Theory - Volume 109
Non-clairvoyant speed scaling for weighted flow time
ESA'10 Proceedings of the 18th annual European conference on Algorithms: Part I
Minimizing maximum flowtime of jobs with arbitrary parallelizability
WAOA'10 Proceedings of the 8th international conference on Approximation and online algorithms
Server Scheduling to Balance Priorities, Fairness, and Average Quality of Service
SIAM Journal on Computing
Scalably scheduling processes with arbitrary speedup curves
ACM Transactions on Algorithms (TALG)
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We consider the problem of scheduling a collection of dynamically arriving jobs with unknown execution times so as to minimize the average flow time. This is the classic CPU scheduling problem faced by time-sharing operating systems where preemption is allowed. It is easy to see that every algorithm that doesn't unnecessarily idle the processor is at worst n-competitive, where n is the number of jobs. Yet there was no known nonclairvoyant algorithm, deterministic or randomized, with a competitive ratio provably O(n1−ε). In this article, we give a randomized nonclairvoyant algorithm, RMLF, that has competitive ratio O(log n log log n) against an oblivious adversary. RMLF is a slight variation of the multilevel feedback (MLF) algorithm used by the UNIX operating system, further justifying the adoption of this algorithm. It is known that every randomized nonclairvoyant algorithm is Ω(log n)-competitive, and that every deterministic nonclairvoyant algorithm is Ω(n1/3)-competitive.