Method for managing virtual memory to separate active and stable memory blocks
US4758944A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1984 |
| Grant date | Jul 19, 1988 |
| Priority date | — |
| Expiry date | Aug 24, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/127
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A pointer, N, indicates an address in a virtual memory space of a demand paged memory including a plurality of virtual address pages and a fixed number of physical memory pages into which blocks of information can be written. A back-up memory store is provided for containing paged-out memory pages. The pointer, N, is advanced along the virtual address pages to indicate the next available virtual address page for allocation, and newly allocated blocks are located on the virtual address page pointed to by said pointer N. Should the necessary space for a block allocation not exist on the page pointed to by said pointer, N, a page which is most recently used and least sparsely utilized is identified from the physical pages onto which blocks have been previously written the block is allocated on that page. If no space remains on the virtual address pages in physical memory for block allocation, then, a least recently used and most sparsely allocated page is identified and paged-out to the back-up store.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.