Contents
1. Concepts of Real time Systems (RTS)
2. Characteristics of RTS
3. Types of RTS
4. Comparison between Types of RTS
5. Applications of RTS
6. Challenges of RTS
Contents
1. Concepts of Real time Systems (RTS)
2. Characteristics of RTS
3. Types of RTS
4. Comparison between Types of RTS
5. Applications of RTS
6. Challenges of RTS
A demand-paging system is similar to a paging system, discussed earlier, with a little difference that it uses - swapping.
Processes reside on secondary memory (which is usually a disk).
When we want to execute a process, we swap it into memory.
Rather than swapping the entire process into memory, however, we use a lazy swapper, which swaps a page into memory only when that page is needed.
Since we are now viewing a process as a sequence of pages, rather than one large contiguous address space, the use of the term swap will not technically correct.
A swapper manipulates entire processes, whereas a pager is concerned with the individual pages of a process.
We shall thus use the term pager, rather than swapper, in connection with demand paging.
Burton Smith passed away on April 3, 2018. He gave this talk in 2014.
"This talk proposes a scheme for addressing the operating system resource management problem. Resource management is the dynamic allocation and de-allocation by an operating system of processor cores, memory pages, and various types of bandwidth to computations that compete for those resources. The objective is to allocate resources for optimized responsiveness based on the finite resources available."
Read the full story: https://wp.me/p3RLHQ-ihD
advanced computer architesture-conditions of parallelismPankaj Kumar Jain
This PPT contains Data and Resource Dependencies,Control Dependence,Resource Dependence,Bernstein’s Conditions ,Hardware And Software Parallelism,Types of Software Parallelism
In operating system how frames are allocated and what is the algorithm of allocation of frames and also discussed about Thrashing for clear some ideas! . Thank u!.
In the given presentation, process overview,process management scheduling typesand some more basic concepts were explained.
Kindly refere the presentation.
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some PagesAre Not in Main Memory
Steps in Handling a Page Fault
A demand-paging system is similar to a paging system, discussed earlier, with a little difference that it uses - swapping.
Processes reside on secondary memory (which is usually a disk).
When we want to execute a process, we swap it into memory.
Rather than swapping the entire process into memory, however, we use a lazy swapper, which swaps a page into memory only when that page is needed.
Since we are now viewing a process as a sequence of pages, rather than one large contiguous address space, the use of the term swap will not technically correct.
A swapper manipulates entire processes, whereas a pager is concerned with the individual pages of a process.
We shall thus use the term pager, rather than swapper, in connection with demand paging.
Burton Smith passed away on April 3, 2018. He gave this talk in 2014.
"This talk proposes a scheme for addressing the operating system resource management problem. Resource management is the dynamic allocation and de-allocation by an operating system of processor cores, memory pages, and various types of bandwidth to computations that compete for those resources. The objective is to allocate resources for optimized responsiveness based on the finite resources available."
Read the full story: https://wp.me/p3RLHQ-ihD
advanced computer architesture-conditions of parallelismPankaj Kumar Jain
This PPT contains Data and Resource Dependencies,Control Dependence,Resource Dependence,Bernstein’s Conditions ,Hardware And Software Parallelism,Types of Software Parallelism
In operating system how frames are allocated and what is the algorithm of allocation of frames and also discussed about Thrashing for clear some ideas! . Thank u!.
In the given presentation, process overview,process management scheduling typesand some more basic concepts were explained.
Kindly refere the presentation.
Virtual Memory
• Copy-on-Write
• Page Replacement
• Allocation of Frames
• Thrashing
• Operating-System Examples
Background
Page Table When Some PagesAre Not in Main Memory
Steps in Handling a Page Fault
Useful documents for engineering students of CSE, and specially for students of aryabhatta knowledge university, Bihar (A.K.U. Bihar). It covers following topics: Background, logical vs. physical address space, swapping, contiguous memory
allocation, paging, segmentation
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.
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.
Memory Management
Swapping
Fragmentation
Types of Fragmentation
Paging
Demand Paging
Segmentation
Virtual Memory
Von Neumann Architecture
overlay
Process and Thread
Process Synchronization
Deadlock
CPU Scheduling
process scheduling
Memory Management
Swapping
Fragmentation
Types of Fragmentation
Paging
Demand Paging
Segmentation
Virtual Memory
Von Neumann Architecture
overlay
Process and Thread
Process Synchronization
Deadlock
CPU Scheduling
process scheduling
To manage the computer memory by controlling and coordinating act as memory management. It has resides hardware component, operating system and other applications. Hardware requires according to system requirement such as RAM, chips and hard disks. Operating system such as processor. Programmer does not know where request is gone all the work done by memory management it is in-built functionality. Memory requires two types of logical and physical. In logical part internal allocation of memory has been done.
In physical part, hardware must satisfy the external requirement. It manages the process of allocating memory during runtime. Memory management does two task such as when a program needs a block a memory this would be managed by memory management and assigns the memory another one is when a program no longer needed that is deleted or deallocate by memory management. Main objective of it’s run time mapping from virtual to physical addresses.
Implementation of checking the validity of an arithmetic expression, conversion from infix to postfix form, evaluation of a postfix expression (C code)
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
Delivering Micro-Credentials in Technical and Vocational Education and TrainingAG2 Design
Explore how micro-credentials are transforming Technical and Vocational Education and Training (TVET) with this comprehensive slide deck. Discover what micro-credentials are, their importance in TVET, the advantages they offer, and the insights from industry experts. Additionally, learn about the top software applications available for creating and managing micro-credentials. This presentation also includes valuable resources and a discussion on the future of these specialised certifications.
For more detailed information on delivering micro-credentials in TVET, visit this https://tvettrainer.com/delivering-micro-credentials-in-tvet/
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
MATATAG CURRICULUM: ASSESSING THE READINESS OF ELEM. PUBLIC SCHOOL TEACHERS I...NelTorrente
In this research, it concludes that while the readiness of teachers in Caloocan City to implement the MATATAG Curriculum is generally positive, targeted efforts in professional development, resource distribution, support networks, and comprehensive preparation can address the existing gaps and ensure successful curriculum implementation.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
1. Dynamic Loading
It has been necessary for the entire program and all data of a process to be in physical memory for
the process to execute. The size of a process has thus been limited to the size of physical memory.
To obtain better memory-space utilization, we can use dynamic loading. With dynamic loading,
a routine is not loaded until it is called. All routines are kept on disk in a relocatable load format.
The main program is loaded into memory and is executed. When a routine needs to call another
routine, the calling routine first checks to see whether the other routine has been loaded. If it has
not, the relocatable linking loader is called to load the desired routine into memory and to update
the program’s address tables to reflect this change. Then control is passed to the newly loaded
routine.
Advantages of Dynamic Loading
The advantage of dynamic loading is that a routine is loaded only when it is needed. This method
is particularly useful when large amounts of code are needed to handle infrequently occurring
cases, such as error routines. In this case, although the total program size may be large, the portion
that is used (and hence loaded) may be much smaller.
Dynamic loading does not require special support from the operating system. It is the responsibility
of the users to design their programs to take advantage of such a method. Operating systems may
help the programmer, however, by providing library routines to implement dynamic loading.
Dynamic Linking
With dynamic linking, a stub is included in the image for each library routine reference. The stub
is a small piece of code that indicates how to locate the appropriate memory-resident library routine
or how to load the library if the routine is not already present. When the stub is executed, it checks
to see whether the needed routine is already in memory. If it is not, the program loads the routine
into memory. Either way, the stub replaces itself with the address of the routine and executes the
routine.
Swapping
Swapping is a mechanism in which a process can be swapped temporarily out of main memory
(or move) to secondary storage (disk) and make that memory available to other processes. At some
later time, the system swaps back the process from the secondary storage to main memory.
Though performance is usually affected by swapping process but it helps in running multiple and
big processes in parallel and that's the reason Swapping is also known as a technique for
memory compaction.
2. The total time taken by swapping process includes the time it takes to move the entire process to
a secondary disk and then to copy the process back to memory, as well as the time the process
takes to regain main memory.
The context-switch time in such a swapping system is fairly high. To get an idea of the context-
switch time, let’s assume that the user process is 100 MB in size and the backing store is a standard
hard disk with a transfer rate of 50 MB per second. The actual transfer of the 100-MB process to
or from main memory takes
100 MB/50 MB per second = 2 seconds
The swap time is 200 milliseconds. Since we must swap both out and in, the total swap time is
about 4,000 milliseconds.
Memory Allocation
Main memory usually has two partitions −
Low Memory − Operating system resides in this memory.
High Memory − User processes are held in high memory.
Operating system uses the following memory allocation mechanism.
3. S.N. Memory Allocation & Description
1 Single-partition allocation
In this type of allocation, relocation-register scheme is used to protect user processes
from each other, and from changing operating-system code and data. Relocation
register contains value of smallest physical address whereas limit register contains
range of logical addresses. Each logical address must be less than the limit register.
2 Multiple-partition allocation
In this type of allocation, main memory is divided into a number of fixed-sized
partitions where each partition should contain only one process. When a partition is
free, a process is selected from the input queue and is loaded into the free partition.
When the process terminates, the partition becomes available for another process.
Fragmentation
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.
Fragmentation is of two types −
S.N. Fragmentation & Description
1 External fragmentation
Total memory space is enough to satisfy a request or to reside a process in it, but it
is not contiguous, so it cannot be used.
2 Internal fragmentation
Memory block assigned to process is bigger. Some portion of memory is left unused,
as it cannot be used by another process.
The following diagram shows how fragmentation can cause waste of memory and a compaction
technique can be used to create more free memory out of fragmented memory −
4. 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.