Browse Prior Art Database

Dynamic Relating of Virutal Storage Pages by Elapsed Time

IP.com Disclosure Number: IPCOM000059814D
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Miro, F: AUTHOR

Abstract

A method is described which provides a significant reduction of the number of paging disk accesses. A real disk storage drive can logically be directed into a group of mini disks and the system arranged to provide paging of data between mini-disk and memory.

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Dynamic Relating of Virutal Storage Pages by Elapsed Time

A method is described which provides a significant reduction of the number of paging disk accesses. A real disk storage drive can logically be directed into a group of mini disks and the system arranged to provide paging of data between mini-disk and memory.

At page-out time, a segment's working set of in-storage pages is scanned for pages of equal or approximate time since the most recent reference. Pairs of pageable pages meeting this criterion are paged-out to contiguous 2K slots on the disk using one Input-Output (I/O) operation versus two separate I/O's if paging-out one page at a time to non-contiguous slots. The benefit of the related page pair is observed at page-fault time for either page of the pair. A fault for either page causes both pages to be paged into storage using one disk seek operation for the first page of the pair and then reading in the two contiguous pages into storage. The observation is that pages that stop being referenced at about the same time will probably be used again at about the same time. The result of page-relating is two pages for the cost of one plus the additional disk data transfer time for the second page. Page relating shows its greatest benefit when the real disk is shared between paging and non- paging mini-disks.

Disclosed anonymously.

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