LinuxMM:

LRU has been obsoleted by large address spaces, streaming media and garbage collection, but until 2002 there weren't many replacements available that are suitable to be implemented in a general purpose OS. However, with the advent of LIRS, ARC, Clock-pro and CAR/CART algorithms, it looks like there could be a benefit to Linux in implementing something better than LRU or the unbalanced use-once that is in use currently.

The only problem is, the advanced page replacement algorithms need to keep a history of recently evicted pages, and we don't want to spend too much memory or cpu on that. This page is a template for brainstorming on how we can implement such a framework, and on which of the advanced page replacement algorithms we should experiment with.

Please feel free to edit this page, after having created an account.

The replacement algorithms

Proposals for dealing with non-resident pages

Rik's interface (for implementation, see NonResidentPages):

 * Keeps track of whether a non-resident page was recently evicted
 * and should be immediately promoted to the active/frequency list.
 *
 * The pageout code stores a recently evicted page in this cache
 * by calling remember_page(mapping/mm, offset/vaddr, generation)
 * and can look it up in the cache by calling recently_evicted()
 * with the same arguments.
 */
extern int recently_evicted(void * mapping, unsigned long index, short objgen);
extern void remember_page(void * mapping, unsigned long index, short objgen, short flag);

LinuxMM: AdvancedPageReplacement (last edited 2005-04-21 20:16:17 by nat-pool-bos)