通常,把选择换出页面的算法称为页面置换算法(Page_Replacement Algorithms)。 一个好的页面置换算法,应具有较低的页面更换频率。从理论上讲,应将那些以后不再会访问的页面换出,或将那些在较长时间内不会再访问的页面调出。 ㈠常见置换算法 ① 最佳置换算法(Optimal): 它是由Belady于1966年提出的一种理论上的算法...
关键词:页面置换;LRU;矩阵;内存管理 中图分类号:TP316 文献标识码:A 文章编号:2095—1302(2012)08—0053—02 RealizationofLRUpage—replacementalgorithmusingmatrix DUYa—li (CollegeofInformationEngineering,LongdongUniversity,Qingyang745000,China) Abstract:Memorymanagementofoperatingsystemisaveryimportantresearchdirect...
There are many page replacement algorithms such as least recently used (LRU), first-in-first-out (FIFO), Optimal and the combination of LRU and least frequently used (LFU) are available in memory management. We can improve the performance of page replacement algorithm either develop a new ...
OPT 替换策略(Optimal Replacement Policy) 原来这个策略叫做 MIN,后来改叫做 OPT 了。这样的一种最优策略,是 Belady 大佬多年前开发的。最优替换策略能达到总体未命中数量最少。实现方式是 替换内存中在最远将来才会访问到的页,由此达到缓存未命中率最低 ! Replace the page that will be accessed furthest in ...
A page replacement algorithm with an improved performance over LRU and many other newer replacement algorithms. This is achieved by using reuse distance as a metric for dynamically ranking accessed pages to make a replacement decision. The algorithm was developed by Song Jiang and Xiaodong Zhang. ...
[9] yooys,leeh,ryuy,etal.pagereplacementalgorithmsfornandflashmemorystorages[m].berlin,germanyspringer,2007. [10] parksy,jungd,kangju,etal.cflru:areplacementalgorithmforflashmemory[c]//proc.ofinternationalconferenceoncompilers,architectureandsynthesisforembeddedsystems.newyork,usa:acmpress,2006:234-24...
(b) If there is no free space, use a page replacement algorithm to evict a page. (c) Write the evict page to the disk. Step 3: Read the required page into the newly created free space Step 4: Restart the process There are many page replacement algorithms such as Optimal, Least ...
Essentially, EELRU is an on-line approximation of an optimal algorithm for the LRUSM. We prove that EELRU offers strong theoretical guarantees of performance relative to the LRU replacement algorithm. EELRU can never be more than a factor of 3 worse than LRU, while in a common best case ...
The minimization is stated as an optimization problem under constraints, a method to obtain a class of optimal solution is presented, and a fixed-space replacement algorithm to implement these solutions is proposed. The parameters of this replacement algorithm can be varied to adapt to specific ...