The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 1997
Filed:
Dec. 29, 1993
James W Frandeen, Soquel, CA (US);
Unisys Corporation, Blue Bell, PA (US);
Abstract
A CTOS network comprised of a plurality of workstations provides for virtual demand paging transparently across the network in a manner which permits a large virtual memory to efficiently be provided for each of a plurality of concurrently running applications on a CTOS workstation. Each application running on the workstation is provided with assigned pages and a local clock which operates based on the well known clock algorithm. A unique combination of local policy and global policy is used for page replacement which results in significantly more efficient management of available memory pages. The global policy includes an 'elbow room' enhancement which permits the global page replacement policy to better take into account the individual activity of the concurrently running applications. In addition, enhanced prefaulting and page cleaning are provided, whereby it is made significantly more likely that a running application will find a requested page in its local clock.