What is the static relocation and the dynamic relocation?

What is the static relocation and the dynamic relocation?

When process becomes active again, the OS must reload it in memory. – With static relocation, the process must be put in the same position. – With dynamic relocation, the OS finds a new position in memory for the process and updates the relocation and limit registers.

What is the static relocation in memory?

The first method of relocation is known as static relocation. In this process, the operating system adjusts the memory address of a process to reflect its starting position in memory. Once a process is assigned a starting position in memory, it executes within the space it has been allocated.

What is dynamic relocation in OS?

Dynamic relocation is where data currently stored in the computer memory is relocated to other parts of the computer. This process creates more efficient memory storage while a program is still active.

What is relocation in operating system?

Relocation is the process of assigning load addresses for position-dependent code and data of a program and adjusting the code and data to reflect the assigned addresses.

What are the disadvantages of dynamic relocation with base?

There are also disadvantages to dynamic relocation. Although relatively inexpensive, it does slow down hardware because of the additional operations outlined above. Another consequence of dynamic relocation is that processes cannot share memory.

What does relocatable address mean?

An address expression that has a fixed value, independent of run-time considerations such as where the program is located in memory, is called an absolute address expression. An address expression with a value that depends on run-time considerations is called a relocatable address expression.

What is fragmentation in operating system?

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.

What is contiguous memory allocation?

Contiguous memory allocation is a classical memory allocation model. Here, a system assigns consecutive memory blocks (that is, memory blocks having consecutive addresses) to a process. Contiguous memory allocation is one of the oldest memory allocation methods.

What is compaction OS?

Compaction is a process in which the free space is collected in a large memory chunk to make some space available for processes. In memory management, swapping creates multiple fragments in the memory because of the processes moving in and out.

What is the use of MMU?

An important function of the Memory Management Unit (MMU) is to enable the system to run multiple tasks, as independent programs running in their own private virtual memory space.

What is fragmentation and its types?

Fragmentation is an unwanted problem in the operating system in which the processes are loaded and unloaded from memory, and free memory space is fragmented. Processes can’t be assigned to memory blocks due to their small size, and the memory blocks stay unused.

What do you mean by external fragmentation?

External fragmentation arises when free memory is separated into small blocks and is interspersed by allocated memory. It is a weakness of certain storage allocation algorithms, when they fail to order memory used by programs efficiently.

What is the relocation factor?

Relocation involves ‘push factors’ and ‘pull factors’. Push factors are things that make a firm want to move from an existing location; these are normally negatives about that site. Pull factors attract a company to a new location and are positive reasons why the new location is preferable to the existing location.

What is relocatable loading?

A relocatable loader is a loader which allows this delay of binding time. A relocatable loader accepts as input a sequence of segments, each in a special relocatable load format, and loads these segments into memory.

What is memory compaction?

Memory compaction is the process of moving allocated objects together and leaving empty space together. Consider a system with 3 pages and about 50% of their objects are allocated.

What is virtual memory in OS?

Virtual memory is a common technique used in a computer’s operating system (OS). Virtual memory uses both hardware and software to enable a computer to compensate for physical memory shortages, temporarily transferring data from random access memory (RAM) to disk storage.

What is addressing binding?

The Address Binding refers to the mapping of computer instructions and data to physical memory locations. Both logical and physical addresses are used in computer memory. It assigns a physical memory region to a logical pointer by mapping a physical address to a logical address known as a virtual address.

What is absolute and relocatable program?

Basically, “absolute” mode means that the code and RAM variables will be placed exactly where you tell the assembler it will be, while “relocatable” means the assembler builds code chunks and specifies RAM needs that can be placed wherever the linker finds room for them.

What does relocatable code mean?

Relocatable code is software whose execution address can be changed. A relocatable program might run at address 0 in one instance, and at 10000 in another. Just to confuse the issue, partially built programs are composed of object modules unfortunately called “relocatables”.

What are the advantages of using relocatable code?

Some substantial advantages of using relocatable code:

• It is possible to actually allocate RAM for variables. …
• You get to use modules, meaning different parts of your code are separately built. …
• You can easily prevent code sections from crossing page boundaries. …
• Code is somewhat insulated from memory layout details.