This document summarizes a presentation on virtual memory given by 5 students for their Computer Architecture and Organization course. It includes definitions of virtual memory, how it works using demand paging and segmentation, why it is used to support multitasking and large programs, the mapping and address translation processes, page tables, page size and faults, and advantages and disadvantages of virtual memory such as protection, sharing, and memory and performance overhead.
Operating System
Topic Memory Management
for Btech/Bsc (C.S)/BCA...
Memory management is the functionality of an operating system which handles or manages primary memory. Memory management keeps track of each and every memory location either it is allocated to some process or it is free. It checks how much memory is to be allocated to processes. It decides which process will get memory at what time. It tracks whenever some memory gets freed or unallocated and correspondingly it updates the status.
Operating System
Topic Memory Management
for Btech/Bsc (C.S)/BCA...
Memory management is the functionality of an operating system which handles or manages primary memory. Memory management keeps track of each and every memory location either it is allocated to some process or it is free. It checks how much memory is to be allocated to processes. It decides which process will get memory at what time. It tracks whenever some memory gets freed or unallocated and correspondingly it updates the status.
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some Pages Are Not in Main Memory
Steps in Handling a Page Fault
This Presentation is for Memory Management in Operating System (OS). This Presentation describes the basic need for the Memory Management in our OS and its various Techniques like Swapping, Fragmentation, Paging and Segmentation.
basic of virtual memory and information about page fault locality of reference and working set modules and valid-invalid bits are covered in this presentation graphicaly .
This presentation describes about the various memory allocation methods like first fit, best fit and worst fit in memory management and also about fragmentation problem and solution for the problem.
About Cache Memory
working of cache memory
levels of cache memory
mapping techniques for cache memory
1. direct mapping techniques
2. Fully associative mapping techniques
3. set associative mapping techniques
Cache memroy organization
cache coherency
every thing in detail
Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has been employed for many years, mainly in high-performance computing, but interest in it has grown lately due to the physical constraints preventing frequency scaling. As power consumption (and consequently heat generation) by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some Pages Are Not in Main Memory
Steps in Handling a Page Fault
This Presentation is for Memory Management in Operating System (OS). This Presentation describes the basic need for the Memory Management in our OS and its various Techniques like Swapping, Fragmentation, Paging and Segmentation.
basic of virtual memory and information about page fault locality of reference and working set modules and valid-invalid bits are covered in this presentation graphicaly .
This presentation describes about the various memory allocation methods like first fit, best fit and worst fit in memory management and also about fragmentation problem and solution for the problem.
About Cache Memory
working of cache memory
levels of cache memory
mapping techniques for cache memory
1. direct mapping techniques
2. Fully associative mapping techniques
3. set associative mapping techniques
Cache memroy organization
cache coherency
every thing in detail
Parallel computing is a type of computation in which many calculations or the execution of processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has been employed for many years, mainly in high-performance computing, but interest in it has grown lately due to the physical constraints preventing frequency scaling. As power consumption (and consequently heat generation) by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.
Abhaycavirtual memory and the pagehit.pptxwemoji5816
in this ppt we are learning about the concept of the virtual memory incomputer science with the help of which we run large program in less primary memory
n computer operating systems, demand paging is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it and that page is not already in memory
Fragmentation Defination-
As processes are loaded and removed from memory, the free memory space is broken into little pieces. It happens after sometimes that processes cannot be allocated to memory blocks considering their small size and memory blocks remains unused. This problem is known as Fragmentation.
External fragmentation
Total free RAM space is enough to load a process but the process still cant load because freeblocks of RAM arent contigious.Or free spaces arent located together.
Internal fragmentation
Memory block assigned to process is bigger. Some portion of memory is left unused, as it cannot be used by another process.
External fragmentation can be reduced by compaction or shuffle memory contents to place all free memory together in one large block. To make compaction feasible, relocation should be dynamic.
The internal fragmentation can be reduced by effectively assigning the smallest partition but large enough for the process. worst fit is the reason for that.
Compaction (solution for external frag)
Compaction is a process in which the free space is collected in a large memory chunk to make some space available for processes.
Paging (solution for external frag)
Paging is a memory management technique in which process address space is broken into blocks of the same size called pages (size is power of 2, between 512 bytes and 8192 bytes). The size of the process is measured in the number of pages.
Fragmentation Defination-
As processes are loaded and removed from memory, the free memory space is broken into little pieces. It happens after sometimes that processes cannot be allocated to memory blocks considering their small size and memory blocks remains unused. This problem is known as Fragmentation.
External fragmentation
Total free RAM space is enough to load a process but the process still cant load because freeblocks of RAM arent contigious.Or free spaces arent located together.
Internal fragmentation
Memory block assigned to process is bigger. Some portion of memory is left unused, as it cannot be used by another process.
External fragmentation can be reduced by compaction or shuffle memory contents to place all free memory together in one large block. To make compaction feasible, relocation should be dynamic.
The internal fragmentation can be reduced by effectively assigning the smallest partition but large enough for the process. worst fit is the reason for that.
Compaction (solution for external frag)
Compaction is a process in which the free space is collected in a large memory chunk to make some space available for processes.
Paging (solution for external frag)
Paging is a memory management technique in which process address space is broken into blocks of the same size called pages (size is power of 2, between 512 bytes and 8192 bytes). The size of the process is measured in the number of pages.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
3. What is Virtual Memory ?
Virtual Memory is a storage allocation scheme in which secondary memory can be addressed as
though it were part of main memory.
The purpose of virtual memory is to enlarge the ”Address Space”
With virtual memory –
A system can load larger programs or multiple programs running at the same time, allowing each one
to operate as if it has infinite memory and without having to purchase more RAM.
Virtual Memory can be implemented via-
◦ Demand Paging
◦ Demand segmentation
6. Why we use it?
Multitasking
When a computer user opens multiple programs at once, the data for these programs must be
stored in memory for quick access. The more programs are open, the more memory is needed.
When the computer's physical memory is full, the excess data is stored in virtual memory.
Large Programs
virtual memory allows programmers to create larger and more complex applications. When
these programs are running, they occupy physical memory as well as virtual memory.
10. There are three different types of mapping used for the purpose of cache
memory are as follow:
1. Direct mapping,
2. Associative mapping,
3.and Set-Associative mapping.
11. Demand Paging
* Bring a page into memory only when it is needed
.Less I/O needed
.Less memory needed
.Faster response
.More users
* Page is needed ⇒ reference to it
.invalid reference ⇒ abort
.not-in-memory ⇒ bring to memory
14. Process
A process is an instance of a program running in a computer. It is
close in meaning to task , a term used in some operating systems.
In other words, process is the state of a running program.
18. Paging
Paging is a method of writing data and reading it from,
secondary storage for use in primary storage, also known as
main memory. Paging plays a role in memory management
for a computer's OS (operating system).
19. Page Tables
A page table is the data structure used by a virtual memory system in
a computer operating system to store the mapping between virtual
addresses and physical addresses.
The entire page table may take up too much main memory.
Page tables are also stored in virtual memory.
When a process is running, part of its page table is in main memory.
20. Page Size
Smaller page size, less amount of internal fragmentation.
Smaller page size, more pages required per process.
More pages per process means larger page tables.
Larger page tables means large portion of page tables in virtual
memory.
21. Page Faults
A page fault is a type of exception raised by computer hardware
when a running program accesses a memory page that is not
currently mapped by memory management unit (MMU) into the
virtual address space of a process or we can say, A miss in the page
table is called a page fault.
When the “valid” bit is not set to 1, then the page must be brought in
from disk, possibly replacing another page in memory.
23. Virtual Memory Sharing
Virtual memory makes it easy for processes to share memory as
all memory accesses are decoded using page tables. For processes
to share the same virtual memory, the same physical pages are
referenced by many processes.
The page tables for each process contain the Page Table Entries that
have the same physical PFN.
24. Figure: Sharing Physical Memory Between Processes.
Figure shows two processes that each have physical piece2 in
their virtual memory map.
25. Advantages and Disadvantages of
Virtual Memory
Advantages
1. Protection
2. Sharing
VM supports
◦ Swapping
Disadvantages
Memory requirements (mapping tables)
Longer memory access times (mapping table lookup)
