4.2. Legacy Memory Management Schemes¶
4.2.2. Partitioned Allocation¶
Strategies for how to satisfy a process request of size n from a list of free holes.
- First-fit
Allocate the first hole that is big enough.
- Best-fit
Allocate the smallest hole that is big enough; must search entire list, unless ordered by size. Produces the smallest leftover hole.
- Worst-fit
Allocate the largest hole; must also search entire list. Produces the largest leftover hole.
4.2.3. Fragmentation¶
- External fragmentation
total memory space exists to satisfy a request, but it is not contiguous
- Internal fragmentation
allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being used
