The document discusses heap memory management. It describes the heap as the portion of memory used for indefinitely stored data. A memory manager subsystem allocates and deallocates space in the heap. It keeps track of free space and serves as the interface between programs and the operating system. When allocating memory, the manager either uses available contiguous space or increases heap size from the OS. Deallocated space is returned to the free pool but memory is not returned to the OS when heap usage drops.
Pgp-Pretty Good Privacy is the open source freely available tool to encrypt your emails then you can very securely send mails to others over internet without fear of eavesdropping by cryptanalyst.
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.
Pgp-Pretty Good Privacy is the open source freely available tool to encrypt your emails then you can very securely send mails to others over internet without fear of eavesdropping by cryptanalyst.
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.
Operating system 32 logical versus physical addressVaibhav Khanna
How to utilize memory optimally by manipulating objects in the memory is referred to as memory management.
Program must be brought (from disk) into memory and placed within a process for it to be run
Main memory and registers are only storage CPU can access directly
Memory unit only sees a stream of addresses + read requests, or address + data and write requests
Register access in one CPU clock (or less)
Main memory can take many cycles, causing a stall
Cache sits between main memory and CPU registers
Protection of memory required to ensure correct operation
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 single pass assembler scans the program only once and creates the equivalent binary program. The assembler substitute all of the symbolic instruction with machine code in one pass.
Operating system 32 logical versus physical addressVaibhav Khanna
How to utilize memory optimally by manipulating objects in the memory is referred to as memory management.
Program must be brought (from disk) into memory and placed within a process for it to be run
Main memory and registers are only storage CPU can access directly
Memory unit only sees a stream of addresses + read requests, or address + data and write requests
Register access in one CPU clock (or less)
Main memory can take many cycles, causing a stall
Cache sits between main memory and CPU registers
Protection of memory required to ensure correct operation
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 single pass assembler scans the program only once and creates the equivalent binary program. The assembler substitute all of the symbolic instruction with machine code in one pass.
Unit III
STORAGE MANAGEMENT
Main Memory-Contiguous Memory Allocation, Segmentation, Paging, 32 and 64 bit architecture Examples; Virtual Memory- Demand Paging, Page Replacement, Allocation, Thrashing; Allocating Kernel Memory, OS Examples.
Describe about the heap memory management such as memory allocation & deallocation. Explained the Memory manager functionality and fragmentation issues.
MATHEMATICS BRIDGE COURSE (TEN DAYS PLANNER) (FOR CLASS XI STUDENTS GOING TO ...PinkySharma900491
Class khatm kaam kaam karne kk kabhi uske kk innings evening karni nnod ennu Tak add djdhejs a Nissan s isme sniff kaam GCC bagg GB g ghan HD smart karmathtaa Niven ken many bhej kaam karne Nissan kaam kaam Karo kaam lal mam cell pal xoxo
Building a Raspberry Pi Robot with Dot NET 8, Blazor and SignalR - Slides Onl...Peter Gallagher
In this session delivered at Leeds IoT, I talk about how you can control a 3D printed Robot Arm with a Raspberry Pi, .NET 8, Blazor and SignalR.
I also show how you can use a Unity app on an Meta Quest 3 to control the arm VR too.
You can find the GitHub repo and workshop instructions here;
https://bit.ly/dotnetrobotgithub
4. the subsystem that allocates and
deallocates space within the heap
keeps track of all the free space in heap
storage at all times
serves as an interface between
application programs and the operating
system
MEMORY MANAGER
5. produces a chunk of contiguous heap
memory of the requested size
if no chunk of the needed size is
available, it increases the heap storage
by getting consecutive bytes of virtual
memory from the OS
ALLOCATION
MEMORY
ALLOCATION
6. returns deallocated space to the pool of
free space (so it can reuse the space)
typically does not return memory to the
OS, even if heap usage drops
DEALLOCATION
MEMORY
ALLOCATION
11. 03Principle of Locality
Also known as Locality of Reference
The phenomenon of the same value or
related storage locations being frequently
accessed.
90/10 Rule comes
from the empirical
observation:
“A program spends
90% of its time in
10% of its code.”
12. 03
Two Types of Access Locality
1. Temporal Locality
2. Spatial Locality
Principle of Locality
13. 03
1. Temporal Locality
the memory locations the program
accesses are likely to be accessed again
within a short period of time
Principle of Locality
Example: Instruction in the
body of inner loops
14. 03
2. Spatial Locality
memory locations close to the location
accessed are likely also to be accessed
within a short period of time
Principle of Locality
Example: Traversing the
elements in a one-dimentional
array
22. Boundary Tags
- keeping a free/used bit at both ends of each
chunk
- adjacent to the free/used bit is a count of
the # of bytes
Doubly Linked, Imbedded Free List
- free chunks are linked in a doubly linked list
- chunks must accommodate two boundary
tags and two pointers
COALESCING
REDUCING
FRAGMENTATION
24. Memory-leak Error
- failing to EVER delete data that cannot be
referenced
Dangling-pointer-dereference
[note: dangling pointers - pointers to storage that
has
been deallocated]
- referencing deleted data
MANUAL DEALLOCATION
REQUESTS
25. Object Ownership
- associate an owner with each object (e.g.
functions and their variables)
Reference Counting
- associate a count with each dynamically
allocated object
PROGRAMMING CONVENTIONS &
TOOLS
MANUAL DEALLOCATION
REQUESTS
26. Region-based Allocation
- allocate all objects in the same region; then
delete the entire region
PROGRAMMING CONVENTIONS &
TOOLS
MANUAL DEALLOCATION
REQUESTS