Pagefile reservations
AssigneeMicrosoft Corporation
InventorsYevgeniy M. Bak, Mehmet Iyigun, Landy Wang
Life of this patent
Estimating the term…
Abstract
A system and method for maintaining a pagefile of a computer system using a technique of reserving portions of the pagefile for related memory pages. Pages near one another in a virtual memory space often store related information and it is therefore beneficial to ensure that they are stored near each other in the pagefile. This increases the speed of reading data out of the pagefile because total seek time of a disk drive that stores the pagefile may decrease when adjacent pages in a virtual memory address space are read back from the disk drive. By implementing a reservation system that allows related pages to be stored adjacent to one another, the efficiency of memory management to of the computer system is increased.
Claims20
A method of operating a computing device having a first type of memory and a second type of memory, the first type of memory storing a working set of active memory pages, the method comprising:
- determining a first portion of a pagefile in the second type of memory where first data of a first page of said working set is to be written;
- reserving at least a second portion of the pagefile adjacent to the first portion of the pagefile, for one or more adjacent pages that are no further than a threshold number of pages away from the first page in a virtual memory space.
A computer system adapted to reserve portions of a pagefile, the computer system comprising:
- a volatile memory that stores a plurality of pages;
- a non-volatile memory that stores the pagefile;
- a memory manager that decides to write a first page of said plurality of pages to the pagefile, the memory manager comprising:
- a page table entry comprising reservation information that determines if a first portion of the pagefile is reserved for the first page;
- a page writer that writes the first page to the first portion of the pagefile when a first portion of the pagefile is reserved for the first page.
At least one computer readable storage medium having computer-executable instructions stored thereon which, when executed by a computer comprising a processor, a first type of memory and a second type of memory, the first type of memory storing a working set of active memory pages, cause the computer to perform a method comprising:
- determining a first portion of the pagefile in the second type of memory where first data of a first page of said working set will be written;
- reserving—at least a second portion of the pagefile for one or more adjacent pages that are no further than a threshold number of pages away from the first page in a virtual memory space;
- writing the first data of the first page of said working set to the first portion of the pagefile in the second type of memory;
- determining to write second data of a second page to the pagefile;
- checking whether a reservation exists for the second page, the reservation reserving the second portion of the pagefile-for the second data of the second page;
- checking whether the second page is allocated to a different page;
- and
- if a reservation exists for the second page and the second page is not allocated to a different page, writing the second data of the second page to the second portion of the pagefile.
Dependencies are inferred from the claim text.