least recently used

(operating systems) (LRU) A rule used in a paging system

which selects a page to be paged out if it has been used

(read or written) less recently than any other page. The same

rule may also be used in a cache to select which cache entry

to flush.

This rule is based on temporal locality - the observation

that, in general, the page (or cache entry) which has not been

accessed for longest is least likely to be accessed in the

near future.

(1995-02-15)