A weighted buddy method for dynamic storage allocation

ABSTRACT

An extension of the buddy method, called the weighted buddy method, for dynamic storage allocation is presented. The weighted buddy method allows block sizes of 2k and 3·2k, whereas the original buddy method allowed only block sizes of 2k. This extension is achieved at an additional cost of only two bits per block. Simulation results are presented which compare this method with the buddy method. These results indicate that, for a uniform request distribution, the buddy system has less total memory fragmentation than the weighted buddy algorithm. However, the total fragmentation is smaller for the weighted buddy method when the requests are for exponentially distributed block sizes.

REFERENCES

• 1: Daniel S. Hirschberg, A class of dynamic memory allocation algorithms, Communications of the ACM, v.16 n.10, p.615-618, Oct. 1973 [doi>10.1145/362375.362392]
• 2: Kenneth C. Knowlton, A fast storage allocator, Communications of the ACM, v.8 n.10, p.623-624, Oct. 1965 [doi>10.1145/365628.365655]
• 3: Donald E. Knuth, The art of computer programming, volume 1 (3rd ed.): fundamental algorithms, Addison Wesley Longman Publishing Co., Inc., Redwood City, CA, 1997
• 4: Paul W. Purdom, Jr. , Stephen M. Stigler, Statistical Properties of the Buddy System, Journal of the ACM (JACM), v.17 n.4, p.683-697, Oct. 1970 [doi>10.1145/321607.321617]
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INDEX TERMS

Primary Classification:
  D. Software
  D.4 OPERATING SYSTEMS
      D.4.2 Storage Management
          Subjects: Allocation/deallocation strategies

Additional Classification:
  I. Computing Methodologies
  I.6 SIMULATION AND MODELING

General Terms:
Algorithms, Measurement, Performance

Keywords:
buddy system, dynamic storage allocation, memory allocation, weighted buddy algorithm