Memory allocation is the process of assigning a portion of computer memory to processes or programs during their execution.
- It ensures efficient and effective utilization of available memory while avoiding fragmentation.
Methods of Memory Allocation
- First Fit
- Next Fit
- Best Fit
- Worst Fit
- Quick Fit
1.) First Fit
First Fit is a method used to allocates the first available block of memory that is large enough to satisfy the request.
- The search starts at the beginning of the memory and stops as soon as a suitable block is found.
- Example: If memory blocks are [100, 200, 300, 400] and the process needs 150 units, it will allocate the block of size 200.
2.) Next Fit
Next Fit is similar to First Fit, but instead of always starting at the beginning, it continues searching from the point of the last allocation.
- If it reaches the end, it wraps around to the beginning.
- Example: If the last allocated block was at 300 in [100, 200, 300, 400] and the process needs 150 units, it will allocate the block of size 400.
3.) Best Fit
Best Fit is a method used to allocates the smallest block of memory that is large enough to satisfy the request.
- It searches the entire list of free blocks and picks the most efficient option.
- Example: For memory blocks [100, 200, 300, 400] and a process needing 150 units, it will allocate the block of size 200.
4.) Worst Fit
Worst Fit is a method used to allocates the largest available block of memory that is large enough to satisfy the request.
- This method tries to maximize leftover free space for future allocations.
- Example: For memory blocks [100, 200, 300, 400] and a process needing 150 units, it will allocate the block of size 400.
5.) Quick Fit
Quick Fit is method that uses pre-segregated lists of free memory blocks by size for faster allocation.
- Each list contains blocks of a specific size, allowing processes to directly access a suitable list without searching the entire memory.
- Example: If memory is organized into lists [100, 200, 300], a process needing 150 units will check the 200 list directly.
