Q1. What is Buddy System?
Ans. The buddy system allocates memory from a fixed size segment consisting of physically contiguous pages. Memory is allocated from this segment using a power-of-2 allocator,
- Which satisfies requests in units sized as a power of 2.
4 KB, 8 KB, 16 KB, and so forth.
- A request in units not appropriately sized is rounded up to the next highest power of 2.
If a request for 11 KB is made, it is satisfied with a 16-KB segment.
- When smaller allocation needed than is available, current segment split into two buddies of next lower power of two, continue until appropriate sized segment available.
When kernel request 21 KB of memory.
Figure: Buddy system allocation