Quiz# 6: Memory Management
1. Difference between Paging and Segmented Memory:
In the latter, the process has no pages, only a big block.
Paging always allows a higher degree of multiprogramming.
In Paging, the instructions for a process can be spread out in memory. Segmented memory does not allow that.
In Segmented memory, pages cannot be swapped out.
2. Compaction is:
A technique to compact a process' instructions so that they occupy less memory.
Needed only if the OS uses Paging for allocating memory.
A technique to merge holes in physical memory so that more processes can be loaded into memory.
3. If a virtual address and its corresponding physical address are identical
There is no multiprogramming in the system.
Logical address space of the process is the same as its physical address space.
The system has no virtual memory.
4. A page that is swapped out will always be swapped back into the memory space it previously occupied.
True
False
5. A process with pending I/O is swapped out. Problems:
No problem. It will finish the I/O when it is swapped back in.
If the I/O process is accessing user memory for I/O buffers, it may attempt to use memory that now belongs to another process.
No problem because the I/O process will use OS buffers which the process can read when it is swapped back in.
6. There is no internal fragmentation with the First-fit, Best-fit and the Worst-fit algorithms for memory allocation.
True
False
7. There is no external fragmentation with Paging.
True
False