optimal page replacement algorithm in java

As a result, the task of an optimal page replacement algorithm is to elect the page which can bound the thrashing. In case if the number of pages that are replaced by the requested pages would be referred in the nearby future then there will be additional number of swap-in and swap-out and then the OS has to perform additional replacements then usual which causes performance lack. Uncertainty the page replacement algorithm is not optimal then there will also be thrashing problem.But, if OS allots more frames to the process then there are more chances of internal-fragmentation.

Just because of lack of frames the most of the pages will be existing in the primary memory and thus more page faults will occur.

In case if the number of frames which are allotted to a process is not adequate or precise then there exist possibility of thrashing problem.

Page replacement is done whenever the requested page is not-found in the main memory. The replacement process is sometimes called as swap out/write to disk. The page replacement algorithms actually elects which memory page is to be replaced. 229-234.Advertisement Page Replacement Algorithms on Hardware/software codesign and system synthesis. Demand Paging for One-NAND#8482 Flash eXecute-in-place. Memory Resource Man-agement in VMware ESX Server. Page Replacement Using Marginal Loss Functions. However it is used as a reference for other page replacement algorithms. Note that optimal page replacement algorithm is not practical as we cannot predict future. We can use an unorderedset in place of vector so that search operation can be done in O (1) time. on Measurement and Modeling of Computer Systems. The above implementation can optimized using hashing. Adaptive Page Re-placement Based on Memory Reference Be-havior. Sym-posium on Memory Management, Vancouver, Canada, 2004, pp.

Operating Systems Concepts with Java, 7th Edition, J. Modern Operating Systems, Prentice Hall, 2nd edition, 2001. MOSS Memory Management Simulator User Guide, Google Scholar MOSS Memory Management Simulator, Google Scholar.Tanenbaum, Page Replacement Algorithms, PHR Google Scholar By running various simulations, students can collect page replacement statistics thus comparing the performance of various replacement algorithms. Moreover, class projects may be assigned requiring operating system students to code new page replacement algorithms which they want to simulate and integrate them into the MOSS VM simulator code files thus enhancing the students' Java coding skills. Equipped with a GUI for control and page table visualization, it allows the student to visually see how page tables operate and which pages page replacement algorithms evict in case of a page fault. The simulator clearly demonstrates the behavior of the page replacement algorithms in a virtual memory system, and provides a convenient way to illustrate page faults and their corresponding page fault costs. We have modified the Java source code of the MOSS virtual memory simulator to allow users to easily switch between different page replacement algorithms including FIFO, LRU, and Optimal replacement algorithms. Computer system courses have long benefited from simulators in conveying important concepts to students.

Optimal page replacement algorithm in java