least recently used

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)