Test: Fragmentation - Computer Science Engineering (CSE) MCQ

Which of the following statements stands true for memory compaction method.

1. it involves movement of code and data in the memory.
2. it is feasible only if computer system provides relocation register;the relocation can be achieved by simply changing the address in the relocation register
3. it does not involves movement of code and data in the memory
4. it does not involves use of relocation register

In ________ memory binding are changed in such manner that all free memory area can be merged to form a single free memory area.

Buddy system and power of 2 allocators leads to ___________

Which of the following statement is true for buddy system allocators?

1. Buddy System splits and recombines memory blocks in a predetermined manner during allocation and deallocation.
2. No splitting of blocks takes place, also no effort is made to coalesce adjoining blocks to form larger blocks; when released, a block is simply returned to its free list.
3. When a request is made for m bytes, the allocator first check the free list containing blocks whose size is 2i for the smallest value of i such that 2i ≥ m.if the free list is empty ,it checks the list containing blocks that are higher the next higher power of 2 in size on so on. an entire block is allocated to a request.
4. When a request is made for m bytes. the system finds the smallest power of 2 that is ≥ m. Let this be 2i.if the list is empty, it checks the lists for block of size 2i+1.it takes one block off this list and splits it into two halves of size 2i.it put one of these blocks into the free list of size 2i,and uses the other block to satisfy the request.

Which of the following statement is true for Power-of-2 allocators?

1. Buddy System splits and recombines memory blocks in a predetermined manner during allocation and deallocation.
2. No splitting of blocks takes place, also no effort is made to coalesce adjoining blocks to form larger blocks; when released, a block is simply returned to its free list.
3. When a request is made for m bytes, the allocator first check the free list containing blocks whose size is 2i for the smallest value of i such that 2i ≥ m.if the free list is empty ,it checks the list containing blocks that are higher the next higher power of 2 in size on so on. an entire block is allocated to a request.
4. When a request is made for m bytes. the system finds the smallest power of 2 that is ≥ m. Let this be 2i.if the list is empty, it checks the lists for block of size 2i+1.it takes one block off this list and splits it into two halves of size 2i.it put one of these blocks into the free list of size 2i,and uses the other block to satisfy the request.

The power of 2 allocators is faster than the Buddy System allocators.

The buddy and power of 2 allocators are faster than the first-fit ,best-fit, next-fit allocators