Lab 06

NCTU OSDI Lab 6: Allocator

Documentation: Lab 6

Lab 6 Demo Release

Required

• Required 1
  • Implement the buddy system for contiguous pages allocation.
• Requried 2
  • Implement the API for register a fixed-size allocator.
  • Implement the API for allocate and free for fixed-size object.
• Required 3
  • Implement a varied-sized allocator.

Elective

• Elective 1
  • Implement the startup allocator.
• Elective 2
  • Replace the static memory allocator with the dynamic memory allocator in your kernel.

Questions

• Is buddy allocator perfectly eliminate external fragmentation? If yes, prove it? If no, give an external fragmentation example.
• If the registered object size is 2049 byte, one page frame can only fit in one object. Hence the internal fragmentation is around 50%. How to decrease the percentage of the internal fragmentation in this case?
• What’s the benefit to prevent static allocation?