Issue No. 02 - February (1979 vol. 28)
M.C. Easton , IBM Thomas J. Watson Research Center
In paged storage systems, page replacement policies generally depend on a use bit for each page frame. The use bit is automatically turned on when the resident page is referenced. Typically, a page is considered eligible for replacement if its use bit has been scanned and found to be off on ? consecutive occasions, where ? is a parameter of the algorithm. This investigation focuses on the dependence of the number of bit-scanning operations on the value of ? and on properties of the string of page references. The number of such operations is a measure of the system overhead incurred while making replacement decisions. In particular, for several algorithms, the number of scans per reference is shown to be approximately proportional to ? However, empirical results from single-program traces show that the value of ? has little effect on the miss ratio. Although the miss ratios for the bit-scanning algorithms are close to those of least recently used (LRU), it is pointed out that increasing the value of ? need not bring the bit-scanning policies closer to LRU management.
operating system overhead, Miss ratio, page fault rate, paged memories, page replacement algorithms, paged storage
M. Easton and P. Franaszek, "Use Bit Scanning in Replacement Decisions," in IEEE Transactions on Computers, vol. 28, no. , pp. 133-141, 1979.