Operating Systems Chapter 2 Practice Test

True

A large job can have problems with a firstfit memory allocation scheme. True or False

False

A single user system supports multiprogramming. True or False

Null entry

A(n) ____ in the busy list occurs when a memory block between two other busy memory blocks is returned to the free list. a. blank line b. null entry c. joined entry d. empty entry

True

After relocation and compaction, both the free list and the busy list are updated. True or False

Overhead

By compacting and relocating, the Memory Manager optimizes the use of memory and thus improves throughput. However, it also requires more ___ than the other memory allocation schemes discussed in this chapter. a. null entries b. segmentation c. main memory d. overhead

False

Compaction should always be performed only when there are jobs waiting to get in. True or False

static

Fixed partitions are also called ___ partitions . a. complete b. static c. direct d. Sized

False

For a fixed partition system, memory deallocation is relatively complex. True or False

True

In a dynamic partition system, a null entry in the busy list occurs when a memory block between two other busy memory blocks is returned to the free list. True or False

True

In a fixed partition scheme, large jobs will need to wait if the large partitions are already booked, and they will be rejected if they're too big to fit into the largest partition. True or False

Relocation register

In a relocatable dynamic partition scheme, the ___ contains a value that must be added to each address referenced in a program so that the system will be able to access the correct memory addresses after relocation. a. bounds register b. load register c. relocation register d. compaction register

Bounds register

In a relocatable dynamic partition scheme, the ____ ensures that, during execution, a program won't try to access memory locations that don't belong to it. a. relocation register b. load register c. compaction register d. bounds register

Sequentially

In a single user system jobs are processed ____. a)Sequentially b) intermittently c) randomly d) in order of longest job to shortest job.

Partition size, memory address, access, and status

In the fixed partition memory management scheme, the table that the Memory Manager uses to keep track of jobs is composed of the ____. a. partition size, memory address, and status b. status, access, and memory address c. partition size, status, and access d. partition size, memory address, access, and status.

True

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. True or False

Random Access Memory

Main memory is also known as ________. a) Single user memory b) random access memory c) finite memory d) virtual memory

Defragmentation

Memory compaction is also referred to as ____. a. defragmentation b. collection c. reallocation d. dynamic allocation

True

Memory defragmentation is performed by the operating system to reclaim fragmented space. True or False

percentage

One approach to performing compaction is to do it when a certain __ __ of memory becomes busy. a. byte b. percentage c. bit d. Area

True

One of the problems with the bestfit 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. True or False

True

Research continues to focus on finding the optimum allocation scheme. True or False

True

Single user contiguous allocation schemes have the problem of partition intrusion. True or False

True

Single user systems in a non networked environment allocate, to each user, access to all available main memory for each job, and jobs are processed sequentially, one after the other. True or False

Relocatable dynamic partitions

Single user, fixed partition, and dynamic partition memory schemes share unacceptable fragmentation characteristics that were resolved with the development of ____. a. deallocation b. bestfit algorithms c. relocatable dynamic partitions d. null entry accounting

first-fit memory allocation

The ____ method keeps the free/busy lists organized by memory locations, from low order Memory to high order memory. a. fixed partition allocation b. firstfit memory allocation c. dynamic fit memory allocation d. bestfit memory allocation

True

The algorithm used to store jobs into memory in a fixed partition system 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. True or False

False

The bestfit allocation method keeps the free/busy lists organized by memory locations, low order memory to high order memory. True or False

True

The bounds register is used to store the highest (or lowest, depending on the specific system) location in memory accessible by each program. True or False

True

The first attempt to allow for multiprogramming used fixed partitions. True or False

False

The firstfit algorithm assumes that the Memory Manager keeps only one list containing free memory blocks. True or False

False

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. True or False

True

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. True or False

All jobs are of similar size

The fixed partition scheme works well when ____. a. all jobs are of similar size b. jobs have different sizes c. job sizes are not known in advance d. all jobs are under 100K

Loaded into memory

The four memory management techniques presented in this chapter share the requirement that the entire program being executed must be ____. a. loaded into memory b. stored on disk c. written in a single language d. Relocatable

Bestfit

The goal of the ___ memory allocation algorithm is to find the smallest memory block into which a job will fit. a. smallest fit b. firstfit c. dynamic fit d. bestfit

Internal fragmentation

The phenomenon of less than complete use of memory space in a fixed partition is called _ __. a. dynamic fragmentation b. internal fragmentation c. external fragmentation d. fixed fragmentation

Fragmentation

The release of memory space by the Memory Manager is called ____. a. fragmentation b. relocation c. free memory d. deallocation

Function

When reading an instruction, the operating system can tell the ____ of each group of digits by its location in the line and the operation code. a. function b. value c. order d. Assignment

External fragmentation

__ consists of fragments of free memory between blocks of allocated memory. a. An inefficient fit b. Indirect partitioning c. External fragmentation d. Internal fragmentation

Compaction

__ of memory is performed by the operating system to reclaim fragmented sections of the memory space. a. Deallocation b. Redirection c. Compaction d. Reallocation