| 摘要 |
PURPOSE:To decrease UIC updating overheads by providing a means to store the frequency of a page-reference and the presence/absence of the rewriting of page-constant for every page of virtual space. CONSTITUTION:In an entry of a page table used for address conversion, R, C bits representing the page-reference frequency and the presence/absence of the rewriting of page content are provided. By designating the head and the length of the page table, the bit R can be read out even consecutively, and the need for obtaining a real page address by pursuing the chain of a page- frame-table PFT is eliminated, also, the need for using an RRB (Reset Reference Bit) instruction whose processing time is long for accessing a main storage key is made unnecessary even for referring to the RC bits, instead of it, an instruction for accessing general main storages can be used, hence the unreferring time interval counting UIC updating processing by an operating system OS can be made speedy. Also, even when the capacity of the main storage is increased, a memory for the bits R, C does not need to be added, therefore, the quantity of hardwares can be reduced.
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