Question 1

A large job can have problems with a first-fit memory allocation list.

Accepted Answer

In a first-fit memory allocation list, the first available block of memory that is large enough to fit the request is allocated to the process. If a large job is allocated first, it may lead to fragmentation of memory and other memory allocation problems. Thus, a first-fit memory allocation list may have problems with large jobs.

Question 2

One of the problems with the best-fit algorithm is that the entire table must be searched before the allocation can be made because the memory blocks are physically stored in sequence according to their location in memory.

Accepted Answer

The best-fit algorithm searches for the best-fit memory block by iterating through the entire table of memory blocks in sequence, starting from the beginning of memory. Therefore, the entire table must be searched before the allocation can be made.

Question 3

The fixed partition scheme does not require that the entire program be stored contiguously and in memory from the beginning to the end of its execution.

Accepted Answer

The fixed partition scheme does require that the entire program be stored contiguously in memory for its execution, but it is the dynamic partitioning scheme that allows programs to be allocated memory wherever it fits, not necessarily contiguously.

Question 4

The problem of partition intrusion is present in single-user contiguous allocation schemes.

Accepted Answer

The answer of The problem of partition intrusion is present...

Question 5

A null entry in the busy list occurs when a memory block between two other busy memory blocks is returned to the free list.

Accepted Answer

When a memory block is returned to the free list, it means that it is no longer busy or currently in use. In this case, there would be a gap or null entry in the busy list between two other busy memory blocks.

Question 6

The first-fit algorithm assumes that the Memory Manager keeps only one list containing free memory blocks.

Accepted Answer

The answer of The first-fit algorithm assumes that the Memory...

Question 7

In the relocatable dynamic partitions scheme, the Memory Manager relocates programs to gather together all of the empty blocks and compact them to make one block of memory large enough to accommodate some or all of the jobs waiting to get in.

Accepted Answer

In the relocatable dynamic partitions scheme, the Memory Manager does indeed relocate programs to gather together all of the empty blocks and compact them to make one block of memory large enough to accommodate some or all of the jobs waiting to get in.

Question 8

In a fixed partition scheme, large jobs may have a longer turnaround time as they wait for free partitions of sufficient size or may never run.

Accepted Answer

In a fixed partition scheme, free partitions may not be available for large jobs, leading to longer wait times or the job not running at all. This is because the size of the partitions is predetermined and cannot be changed dynamically based on the size of the job.

Question 9

A single-user system supports multiprogramming.

Accepted Answer

A single-user system typically does not support multiprogramming because multiprogramming involves running multiple programs concurrently, which is a feature more commonly associated with multi-user or multitasking operating systems.

Question 10

The best-fit free list scheme uses memory more efficiently than the first-fit free scheme but it is slower to implement.

Accepted Answer

The best-fit free list scheme searches for the smallest available block that can accommodate the requested memory. This results in less fragmentation and better memory utilization compared to first-fit scheme. However, the search process takes longer, making it slower to implement.

Question 11

The best-fit allocation method keeps the free/busy lists organized by memory locations, low-order memory to high-order memory.

Accepted Answer

The best-fit allocation method organizes free memory blocks by size, not by their physical location in memory, to find the smallest block that satisfies a request.

Question 12

Early memory management schemes are still used in today's operating systems.

Accepted Answer

The answer of Early memory management schemes are still used...

Question 13

The first step in loading a job in a single-user system is storing the first memory location of program into the base register (for memory protection).

Accepted Answer

This is true. Storing the first memory location of a program into the base register is a common technique used in single-user systems for memory protection.

Question 14

To overlay is to transfer segments of a program from main memory into secondary storage for execution, so that two or more segments take turns occupying the same memory locations.

Accepted Answer

Overlay is a technique used to load program segments into the same memory space, but it involves transferring segments from secondary storage to main memory, not the other way around.

Question 15

Research continues to focus on finding the optimum allocation scheme.

Accepted Answer

The sentence states that research is ongoing to find the best allocation scheme, indicating that the statement is true.

Question 16

The algorithm used to store jobs into memory requires a few more steps than the one used for a single-user system because the size of the job must be matched with the size of the partition to make sure it fits completely.

Accepted Answer

This statement is true. In a multi-user system, the algorithm must take into account the size of the job and match it with an appropriately sized partition in memory to ensure it fits completely. This is necessary to avoid fragmentation and optimize memory usage.

Question 17

All computers have only a finite amount of memory and if a program doesn't fit, then either the size of the main memory must be increased or the program must be modified.

Accepted Answer

All computers have a limited amount of memory and if a program is too large to fit, the options are to increase the memory or modify the program to require less memory.

Question 18

For a fixed partition system, memory deallocation is quite complex.

Accepted Answer

For a fixed partition system, memory deallocation is not complex as each partition has a fixed and known size, and a process can only occupy one partition at a time. Deallocating memory simply involves marking the partition as available again.

Question 19

The fixed partition scheme works well if all of the jobs run on the system are of the same size or if the sizes are known ahead of time and don't vary between reconfigurations.

Accepted Answer

The fixed partition scheme is designed to divide memory into equal-sized partitions, which is beneficial if all jobs running on the system are of the same size or the sizes are known in advance and don't change over time.

Question 20

The first attempt to allow for multiprogramming used fixed partitions.

Accepted Answer

The first attempt to allow for multiprogramming did use fixed partitions, which divided the computer's memory into fixed sections to allocate to different programs.

Quiz 2: Memory Management: Early Systems