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EDA (Extended Dynamic Allocation)

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Extended Dynamic Allocation (EDA) is a memory management technique used in computer systems to allocate memory dynamically to processes. EDA is an extension of the Dynamic Memory Allocation technique used in many operating systems. EDA is used in situations where the processes require a large amount of memory to complete their tasks.

In this article, we will discuss EDA in detail, including its definition, working, advantages, and disadvantages.

Definition of Extended Dynamic Allocation (EDA)

EDA is a memory management technique used in computer systems to allocate memory dynamically to processes. In this technique, the system assigns memory to a process when it is requested, and when the process is completed, the system releases the memory back to the pool of available memory. EDA is used to allocate memory in small chunks, which is more efficient than allocating memory in large blocks.

Working of Extended Dynamic Allocation (EDA)

EDA works by allocating memory to a process in small chunks, which are called "pages." Each page is a fixed-size block of memory, typically 4KB or 8KB in size. When a process requests memory, the system assigns it a number of pages, depending on the amount of memory required. The pages are allocated from a pool of free memory, which is managed by the operating system.

When a process is completed, the system releases the memory back to the pool of free memory, making it available for other processes to use. The pages are not released immediately, but are kept in a pool of "free pages" until they are needed again. This is known as "page recycling."

EDA uses a data structure called a "page table" to keep track of the pages allocated to a process. The page table contains a list of all the pages allocated to the process, along with information about the location of each page in memory. When a process accesses memory, the system uses the page table to translate the virtual memory address used by the process into a physical memory address.

Advantages of Extended Dynamic Allocation (EDA)

  1. Efficient memory usage: EDA allocates memory in small chunks, which is more efficient than allocating memory in large blocks. This is because the system can allocate exactly the amount of memory required by a process, rather than allocating a large block of memory that may not be fully utilized.
  2. Memory protection: EDA provides memory protection, which prevents processes from accessing memory that does not belong to them. Each process has its own page table, which ensures that it can only access its own memory.
  3. Virtual memory: EDA enables the use of virtual memory, which allows processes to access more memory than is physically available in the system. This is achieved by using a combination of RAM and disk storage.
  4. Page recycling: EDA uses page recycling to keep the pages in memory until they are needed again. This improves memory utilization and reduces the overhead of allocating and deallocating memory.

Disadvantages of Extended Dynamic Allocation (EDA)

  1. Fragmentation: EDA can lead to memory fragmentation, which occurs when small blocks of free memory are scattered throughout the system. This can make it difficult to allocate large blocks of memory, as there may not be enough contiguous free memory available.
  2. Overhead: EDA can introduce overhead, as the system needs to manage the page tables and keep track of the free pages. This can reduce system performance, especially when there are many processes running concurrently.

Conclusion

Extended Dynamic Allocation (EDA) is a memory management technique used in computer systems to allocate memory dynamically to processes. EDA works by allocating memory in small chunks, which are called "pages." EDA provides efficient memory usage, memory protection, virtual memory, and page recycling. However, EDA can lead to memory fragmentation and overhead. Overall, EDA is a useful technique for managing memory in modern computer systems, as it enables efficient and flexible memory allocation and helps to prevent memory-related errors and crashes.

In addition to the advantages and disadvantages discussed above, EDA has several other important features and considerations to be aware of. For example, EDA may use different page sizes depending on the specific hardware and software configurations of a system, and page sizes may be adjusted dynamically based on system load and other factors.