Some Aspects of Hierarchical Memory Systems

ABSTRACT

A class of demand paging algorithms for some two-level memory hierarchies is analyzed. The typical memory hierarchy is comprised of the core and a backing device. A distance matrix characterizes the properties of the latter device. The sequence of address references directed to the hierarchy by the CPU and channels is modeled as a Markov process. A compact expression for the mean time required to satisfy the page demands is derived and this expression provides the basis for some optimization problems concerning partitionings and rearrangements of pages in the backing device. In connection with these problems, a class of random processes is defined in terms of an ordering property of a joint probability matrix which is central to memory hierarchies. Three results are given on the ordering property, its relation specifically to partitionings inherent in hierarchies and the problem of optimal rearrangements. Finally, for such a class of ordered processes, certain results due to the author are specialized to yield the solution to the problem of optimal rearrangement of pages on an assembly of magnetic bubble loops.

REFERENCES

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INDEX TERMS

Primary Classification:
  G. Mathematics of Computing
  G.3 PROBABILITY AND STATISTICS
      Subjects: Markov processes

Additional Classification:
  D. Software
  D.4 OPERATING SYSTEMS

General Terms:
Design, Performance, Theory, Verification