Abstract A system for controlling the transfer of pages between a large disc memory and a much smaller core memory in response to requests for the transfer of pages from the disc memory to the core memory, including a first plurality of control words, which define an In-Core List. Each of these control words is associated with a different core page. The word''s fields are used to designate various information related to the disc page located in the core page associated with the word, as well as the availability of the core page to have a disc page transferred thereto. The system includes circuitry to form a Paging Queue comprising of other control words. Each word in the Paging Queue includes all the information necessary to define which core page should be emptied of which disc page located therein, to make room for a new disc page which is requested, and/or the number of a new disc page and the core page into which it is to be transferred. The transferring of pages between the memories is independent of the order in which page requests are received. The accessibility of the core memory is dynamically variable.
A method for controlling the transferring of pages of information within a computer having a first memory, and a second memory which is smaller and faster than said first memory, wherein each of said pages of information is associated with a page header word containing data pertaining to the job priority of the job being performed and data pertaining to the job priority of the job being performed and data pertaining to the page activity of such associated page, the method comprising: assigning to each received page of information a job priority and a page activity indicator; upon the detection by the computer of a page required to be stored in said second memory where no location for such storage is then available in said second memory, scanning the contents of a linked, nonsequential list of page header words, one after the next, until finding a page header word associated with a page of information of a predetermined low ranking, said ranking being obtained by a logical combination of the data in said page header word pertaining to said job priority and said page activity of the job and page, respectively, with which such header word is associated; and removing said low-ranking page and substituting therefor said page required to be stored.
Claim 2
Independent Claim
212 words
A method for controlling the transferring of pages of information within a computer having a first memory, and a second memory which is smaller and faster than said first memory, wherein each of said pages of information is associated with a page header word containing data pertaining to the job priority of the job being performed and data pertaining to the job priority of the job being performed and data pertaining to the page activity of such associated page, the method comprising: assigning to each received page of information a job priority and a page activity indicator; upon the detection by the computer of a page required to be stored in said second memory where no location for such storage is then available in said second memory, scanning the contents of a linked, nonsequential list of page header words, one after the next, until finding a page header word associated with a page of information of a predetermined low ranking, said ranking being obtained by a logical combination of the data in said page header word pertaining to said job priority and said page activity of the job and page, respectively, with which such header word is associated; and removing said low-ranking page and substituting therefor said page required to be stored.
Claim 3
Dependent Claim
31 words
The method of claim 1 further defined by said ranking also being based in part upon a comparison with a predetermined priority and activity of said page required to be stored.