scholarly journals An Improved Page Replacement Algorithm Using Block Retrieval of Pages

2018 ◽  
Vol 7 (4.5) ◽  
pp. 32 ◽  
Author(s):  
Govind Prasad Arya ◽  
Devendra Prasad ◽  
Sandeep Singh Rana
Keyword(s):  
Operating System ◽  
Execution Time ◽  
Virtual Memory ◽  
Primary Memory ◽  
Page Fault ◽  
Secondary Storage ◽  
Frame Size ◽  
Replacement Algorithm ◽  
Replacement Technique ◽  
Computer Programmer

The computer programmer write programming codes of any length without keeping in mind the available primary memory. This is possible if we use the concept of virtual memory. As the name suggests, virtual memory is a concept of executing a programming code of any size even having a primary memory of smaller size than the size of program to be executed. The virtual memory can be implemented using the concept of paging. The operating system allocates a number of memory frames to each program while loading into the memory. The programming code is equally divided into pages of same size as frame size. The size of pages and memory frames are retained equal for the better utilization of the memory. During the execution of program, every process is allocated limited number of memory frames; hence there is  a need of page replacements. To overcome this limitation, a number of page replacement techniques had suggested by the researchers. In this paper, we have proposed an modified page replacement technique, which is based on the concept of block reading of pages from the secondary storage. The disc access is very slow as compared to the access from primary memory. Whenever there is a page fault, the required page is retrived from the secondary storage. The numerous page faults increase the execution time of process. In the proposed methodology, a number of pages, which is equal to the allotted memory frames, are read every time when there is a page fault instead of reading a single page at a time. If a block of pages has fetched from secondary storage, it will definitely increases the possibilities of page hit and as a result, it will improve the hit ratio for the processes.  

scholarly journals Hybrid Page Replacement Algorithm in real time Operating System

2020 ◽  
pp. 433-439
Author(s):  
Pallab Banerjee ◽  
Biresh Kumar ◽  
Amarnath Singh ◽  
Shipra Sinha ◽  
Medha Sawan
Keyword(s):  
Operating System ◽  
Execution Time ◽  
Virtual Memory ◽  
Primary Memory ◽  
Page Fault ◽  
Secondary Storage ◽  
Real Time Operating System ◽  
Storage Devices ◽  
Replacement Algorithm ◽  
Replacement Technique

Programming codes are of variable length. When the size of codes becomes greater than that of primary memory, the concept of virtual memory comes into play. As the name suggests, virtual memory allows to outstretch the use of primary memory by using storage devices such as disks. The implementation of virtual memory can be done by using the paging approach. Allocation of memory frames to each and every program is done by the operating system while loading them into the memory. Each program is segregated into pages as per the size of frames. Equal size of pages and frames enhance the usability of memory. As, the process or program which is being executed is provided with a certain amount of memory frames; therefore, swap out technique is necessary for the execution of each and every page. This swap out technique is termed as Page Replacement. There are many algorithms proposed to decide which page needs to be replaced from the frames when new pages come. In this paper, we have proposed a new page replacement technique. This new technique is based on the approach of reading and counting of the pages from secondary storage. Whenever the page fault is detected, the needed page is fetched from the secondary storage. This process of accessing the disc is slow as compared to the process in which the required page is retrieved from the primary storage. In the proposed technique, the pages having least occurrence will be replaced by the new page and the pages having same count will be replaced on the basis of LRU page replacement algorithm. In this method, the paged are retrieved from the secondary storage hence, possibility of page hit will be increased and as a result, the execution time of the processes will be decreased as the possibility of page miss will be decreased.

scholarly journals Refresh Rate Identification Strategy for Optimal Page Replacement Algorithms for Virtual Memory Management

2021 ◽  
Vol 9 (11) ◽  
pp. 166-169
Author(s):  
Gajanan Digambar Gaikwad
Keyword(s):  
Operating System ◽  
Memory Management ◽  
Virtual Memory ◽  
Main Memory ◽  
Primary Memory ◽  
Refresh Rate ◽  
Virtual Memory Management ◽  
Replacement Algorithm ◽  
Replacement Algorithms ◽  
Keywords Aging

Abstract: Operating system offers a service known as memory management which manages and guides primary memory. It moves processes between disk and main memory during the execution back and forth. The process in which we provisionally moves process from primary memory to the hard disk so the memory is available for other processes. This process is known as swapping. Page replacement techniques are the methods by which the operating system concludes which memory pages to be swapped out and write to disk, whenever a page of main memory is required to be allocated. There are different policies regarding how to select a page to be swapped out when a page fault occurs to create space for new page. These Policies are called page replacement algorithms. In this paper the strategy for identifying the refresh rate for ‘Aging’ page replacement algorithm is presented and evaluated. Keywords: Aging algorithm, page replacement algorithm, refresh rate, virtual memory management.

Study of Page Replacement Algorithm Based on Experiment

2014 ◽  
Vol 530-531 ◽  
pp. 895-898
Author(s):  
Hong Wang
Keyword(s):  
Virtual Memory ◽  
Page Fault ◽  
Replacement Algorithm ◽  
Memory Control

The page replacement algorithm is an very important step which realize virtual memory control. A good page replacement algorithm can reduce the fault frequency when program executing, reduce the number of I/O, and then increase the systems efficiency effectively. In this paper, we studied the principle of various of page replacement algorithm, designed an program which simulated the procession and result of page replacement algorithm, in this program, we assume a few condition, record the experiment results. According to these data, we compared and analyzed the page fault and page fault frequency of different algorithm, and compare their performance.

scholarly journals How Anomalous Is Beladv's Anomaly?

10.28945/3390 ◽  
2009 ◽  
Author(s):  
Kirby McMaster ◽  
Samuel Sambasivam ◽  
Nicole Anderson
Keyword(s):  
Computer Simulation ◽  
Virtual Memory ◽  
Memory System ◽  
Page Fault ◽  
String Length ◽  
Replacement Algorithm ◽  
Wide Range

In a virtual memory system using demand paging, the page fault rate of a process varies with the number of memory frames allocated to the process. When an increase in the number of frames allocated leads to an increase in the number of page faults, Belady's anomaly is said to occur. In this study we used computer simulation to examine four conditions that affect the incidence of Belady's anomaly: (1) page replacement algorithm (FIFO vs. Random Page), (2) process size, (3) reference string length, and (4) memory frames allocated to the process. We found that over a wide range of process sizes and reference string lengths, Belady's anomaly occurred for up to 58.6% of the (random) reference strings under FIFO, and up to 100% of the reference strings for Random Page. Under conditions where anomalies occur most often, the average frame allocation level was around 75% of the process size for FIFO, but just over 50% of the process size for Random Page. Throughout the study, Belady's anomaly occurred so frequently that it no longer seems anomalous. This is especially true for the Random Page algorithm.

scholarly journals Critical Scrutiny of Page Replacement Algorithms: FIFO, Optimal and LRU

2020 ◽  
Vol 9 (10) ◽  
pp. 345-348
Keyword(s):  
Memory Management ◽  
Virtual Memory ◽  
Main Memory ◽  
Primary Memory ◽  
Secondary Memory ◽  
Memory Space ◽  
System A ◽  
Replacement Technique ◽  
Critical Scrutiny ◽  
Replacement Algorithms

Virtual memory plays an important role in memory management of an operating system. A process or a set of processes may have a requirement of memory space that may exceed the capacity of main memory. This situation is addressed by virtual memory where a certain memory space in secondary memory is treated as primary memory, i.e., main memory is virtually extended to secondary memory. When a process requires a page, it first scans in primary memory. If it is found then, process continues to execute, otherwise a situation arises, called page fault, which is addressed by page replacement algorithms. This algorithms swaps out a page from main memory to secondary memory and replaced it with another page from secondary memory in addition to the fact that it should have minimum page faults so that considerable amount of I/O operations, required for swapping in/out of pages, can be reduced. Several algorithms for page replacement have been formulated to increase the efficiency of page replacement technique. In this paper, mainly three page replacement algorithms: FIFO, Optimal and LRU are discussed, their behavioural pattern is analysed with systematic approach and a comparative analysis of these algorithms is recorded with proper diagram.

A buffer based page replacement algorithm to reduce page fault

2020 ◽  
Vol 33 ◽  
pp. 4557-4560
Author(s):  
S. Muthusundari ◽  
M.A. Berlin ◽  
J. Geetha Priya ◽  
K. Balasaranya
Keyword(s):  
Page Fault ◽  
Replacement Algorithm

Performance Evaluation for Dynamic Voltage and Frequency Scaling Using Runtime Performance Counters

2013 ◽  
Vol 284-287 ◽  
pp. 2575-2579 ◽  
Author(s):  
Wen Yew Liang ◽  
Ming Feng Chang ◽  
Yen Lin Chen ◽  
Jenq Haur Wang
Keyword(s):  
Operating System ◽  
Performance Evaluation ◽  
Execution Time ◽  
System Performance ◽  
Evaluation Method ◽  
Reducing Power ◽  
General Purpose ◽  
Frequency Scaling ◽  
Dynamic Voltage ◽  
Performance Evaluation Method

Dynamic voltage and frequency scaling (DVFS) is an effective technique for reducing power consumption. The system performance is not easy to evaluate through Dynamic Voltage and Frequency Scaling. Most of studies use the execution time as an indicator while measuring the performance. However, DVFS adjusted processor speed during a fixed-length period so it cannot rely on the execution time to evaluate the system performance. This study proposes a novel and simple performance evaluation method to evaluate the system performance when DVFS is activated. Based on the performance evaluation method, this study also proposes a DVFS algorithm (P-DVFS) for a general-purpose operating system. The algorithm has been implemented on the Linux operating system and used a PXA270 development board. The results show that P-DVFS could accurately predict the suitable frequency, given runtime statistics information of a running program. In this way, the user can easily control the energy consumption by specifying allowable performance loss factor.

Phase Retrieval Holography for Particle Measurement With GPU Acceleration

2019 ◽  
Author(s):  
Yohsuke Tanaka ◽  
Hiroki Matsushi ◽  
Shigeru Murata
Keyword(s):  
Operating System ◽  
Execution Time ◽  
Phase Retrieval ◽  
Small Volume ◽  
Graphics Processing Unit ◽  
Gpu Acceleration ◽  
Processing Unit ◽  
Drastic Reduction ◽  
Particle Measurement ◽  
Graphics Processing

Abstract We introduce a graphics processing unit (GPU) acceleration to reconstructing holograms of phase retrieval holography for a drastic reduction of the execution time. We conducted GPU acceleration using the FFT library CUFFT on the GPU chip (GEFORCE GTX 1050, GDDR5 2GB, NVIDIA). We also used Intel Xeon CPU (E5-2690, 2.90GHz, Intel), the memory of 24 GB, and the operating system of Ubuntu 16.04 to compare GPU and CPU. Reconstructed volumes changed from 2562 × 128 voxels to 20482 × 1024 voxel to compare execution times. The ratio of the time of GPU to that of CPUs is constantly higher than 100 times except for small volume. We also demonstrated that GPU acceleration decreased the time by observing falling particles, recorded in 40 frames, from particle feeder. As a result, it is found that the execution time is reduced from 13 hours to 30 minutes.

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