test

Chapter 8 main memory

The _____ is an approximation of a program's locality.       working set

A(n) ______ matches the process with each entry in the TLB        address-space identifier

An address generated by a CPU is referred to as a ____.   logical address

Without a mechanism such as an address-space identifier, the TLB must be flushed
during a context switch.       True

A page fault must be preceded by a TLB miss      True
Inverted page tables require each process to have its own page table False

A 32-bit logical address with 8 KB page size will have 1,000,000 entries in a conventional page table.       False

_____ is the dynamic storage-allocation algorithm which results in the smallest leftover hole in memory.     Best fit

Consider a logic address with a page size of 8KB. How many bits must be used to represent the page offset in the logical address?      13

A(n) ___ page table has one page entry for each real page (or frame) of memory       inverted


___ is the dynamic storage-allocation which results in the largest leftover hold in memory.    Worst fit

Stack algorithms can never exhibit Belady's anomaly      True

A page fault must be preceeded by a TLB miss    True

On a system with demand-paging, a process will experience a high page fault rate when the process just begins execution       True

___ occurs when a process spends more time paging than executing     Thrashing

The ___ allocation algorithm allocates available memory to each process according to its size                        proportional


There is a 1:1 correspondence between the number of entries in the TLB and the number of entries in the page table. False


Chapter 9 virtual memory
Question 1
________ allows the parent and child processes to initially share the same pages, but when either process modifies a page, a copy of the shared page is created. (Full9,Ch9,CG7)
Question 1 options:
           
a)        virtual memory fork
           
b)        copy-on-write
           
c)         zero-fill-on-demand
           
d)        memory-mapped
Save
Question 2
______ allows a portion of a virtual address space to be logically associated with a file. (Full9,Ch9,CG7)
Question 2 options:
           
a)        Shared memory
           
b)        Slab allocation
           
c)         Memory-mapping
           
d)        Locality of reference
Save
Question 3
Windows uses a local page replacement policy _____. (Full9,Ch9,CG7)
Question 3 options:
           
a)        when a process exceeds its working set maximum
           
b)        under all circumstances
           
c)         when a process exceeds its working set minimum
           
d)        when the system undergoes automatic working set trimming
Save
Question 4
Only a fraction of a process's working set needs to be stored in the TLB. (Full9,Ch9,CG7)
Question 4 options:
            a) True
            b) False
Save
Question 5
Non-uniform memory access has little effect on the performance of a virtual memory system. (Full9,Ch9,CG7)
Question 5 options:
            a) True
            b) False
Save
Question 6
In systems that support virtual memory, ____. (Full9,Ch9,CG7)
Question 6 options:
           
a)        physical memory is separated from logical memory.
           
b)        physical memory is separated from secondary storage.
           
c)         virtual memory is separated from logical memory.
           
d)        virtual memory is separated from physical memory.
Save
Question 7
The ____ is the number of entries in the TLB multiplied by the page size. (Full9,Ch9,CG7)
Question 7 options:
           
a)        TLB cache
           
b)        hit ratio
           
c)         page resolution
           
d)        TLB reach
Save
Question 8
Systems in which memory access times vary significantly are known as __________. (Full9,Ch9,CG7)
Question 8 options:
           
a)        demand-paged memory
           
b)        non-uniform memory access
           
c)         memory-mapped I/O
           
d)        copy-on-write memory
Save
Question 9 (6.66 points) Question 9 Saved
In general, virtual memory decreases the degree of multiprogramming in a system. (Full9,Ch9,CG7)
Question 9 options:
            a) True
            b) False
Save
Question 10
The buddy system for allocating kernel memory is very likely to cause fragmentation within the allocated segments. (Full9,Ch9,CG7)
Question 10 options:
            a) True
            b) False
Save
Question 11
The vfork() system call in UNIX ____. (Full9,Ch9,CG7)
Question 11 options:
           
a)        is not intended to be used when the child process calls exec() immediately after creation
           
b)        uses copy-on-write with the fork() call
           
c)         duplicates all pages that are modified by the child process
           
d)        allows the child process to use the address space of the parent
Save
Question 12
On a system with demand-paging, a process will experience a high page fault rate when the process begins execution. (Full9,Ch9,CG7)
Question 12 options:
            a) True
            b) False
Save
Question 13
The _____ is an approximation of a program's locality. (Full9,Ch9,CG7)
Question 13 options:
           
a)        working set
           
b)        locality model
           
c)         page fault frequency
           
d)        page replacement algorithm
Save
Question 14 (6.66 points) Question 14 Saved
The _____ allocation algorithm allocates available memory to each process according to its size. (Full9,Ch9,CG7)
Question 14 options:
           
a)        global
           
b)        slab
           
c)         equal
           
d)        proportional
Save
Question 15 (6.66 points) Question 15 Saved
_____ occurs when a process spends more time paging than executing. (Full9,Ch9,CG7)
Question 15 options:
           
a)        Swapping
           
b)        Thrashing
           
c)         Memory-mapping
           
d)        Demand paging

chapter 11 file system

Question 1 

A mount point is _____. (Full9,Ch11,CG6)

 
a) 
the location within the file structure where the file system is to be attached.
 
b) 
a location of a shared file system
 
c) 
only appropriate for shared file systems
 
d) 
a root of the file system

Question 2 

The path name /home/people/os-student/chap11.txt is an example of (Full9,Ch11,CG6)
 
a) 
a relative path name
 
b) 
an absolute path name
 
c) 
a relative path name to the current directory of /home
 
d) 
an invalid path name

Question 3 

Windows systems employ mandatory locking. (Full9,Ch11,CG6)
 
a) True
 
b) False

Question 4 

A(n) ____ file is a series of code sections that the loader can bring into memory and execute. (Full9,Ch11,CG6)
 
a) 
executable
 
b) 
text
 
c) 
source
 
d) 
object

Question 5 

app.exe is an example of a(n) _____. (Full9,Ch11,CG6)
 
a) 
executable file
 
b) 
batch file
 
c) 
text file
 
d) 
object file

Question 6

All files in a single-level directory must have unique names. (Full9,Ch11,CG6)
 
a) True
 
b) False

Question 7 

Which of the following is not considered a file attribute? (Full9,Ch11,CG6)
 
a) 
Name
 
b) 
Resolution
 
c) 
Size
 
d) 
Protection

Question 8 

A shared lock ____. (Full9,Ch11,CG6)
 
a) 
ensures that a file can have only a single concurrent shared lock
 
b) 
will prevent all other processes from accessing the locked file
 
c) 
behaves like a writer lock
 
d) 
behaves like a reader lock

Question 9 

Which of the following is true of the tree-structured directory structure? (Full9,Ch11,CG6)
 
a) 
It is the most common directory structure.
 
b) 
Users cannot create their own subdirectories.
 
c) 
Directories can share subdirectories and files.
 
d) 
Users cannot acquire permission to access the files of other users.

Question 10 

The simplest file access method is ____. (Full9,Ch11,CG6)
 
a) 
sequential access
 
b) 
logical access
 
c) 
relative access
 
d) 
direct access

Question 11 

Which of the following is not considered a classification of users in connection with each file?
 
a) 
current user
 
b) 
owner
 
c) 
universe
 
d) 
group

Question 12 

A(n) ____ file is a sequence of bytes organized into blocks understandable by the system's linker.
 
a) 
object
 
b) 
source
 
c) 
text
 
d) 
executable

Question 13 

An exclusive lock ____. (Full9,Ch11,CG6)
 
a) 
will prevent all other processes from accessing the locked file
 
b) 
behaves like a reader lock
 
c) 
ensures that a file can have only a single concurrent shared lock
 
d) 
behaves like a writer lock

Question 14 

Which of the following is true of the direct-access method? (Full9,Ch11,CG6)
 
a) 
It allows programs to read and write records in no particular order.
 
b) 
It is the most common mode of access.
 
c) 
Files are made up of variable-length records.
 
d) 
It is not a good method for accessing large amounts of data quickly.

Question 15 

A(n) ____ file is a sequence of functions. (Full9,Ch11,CG6)
 
a) 
source
 
b) 
executable
 
c) 
text
 
d) 
object


Chapter 12 file system implementation
Question 1
A contiguous chunk of disk blocks is known as a(n) _____.
           
a)        file-allocation table (FAT)
           
b)        inode
           
c)         extent
           
d)        disk block group

Question 2 On UNIX systems, the data structure for maintaining information about a file is a(n) _____.
           
a)        master file table
           
b)        superblock
           
c)         file-control block (FCB)
           
d)        inode

Question 3
The file-allocation table (FAT) used in MS-DOS is an example of _____.
           
a)        contiguous allocation
           
b)        linked allocation
           
c)         multilevel index
           
d)        indexed allocation

Question 4
Metadata includes all of the file-system structure, including the actual data (or contents of the file).

            a) True
            b) False

Question 5
Which of the following allocation methods ensures that only one access is needed to get a disk block using direct access?
a)        indexed allocation
           
b)        linked allocation
           
c)         contiguous allocation
           
d)        hashed allocation

Question 6
A _____ is a view of a file system before the last update took place.
           
a)        backup
           
b)        consistency checker
           
c)         transaction
           
d)        snapshot

Question 7
Transfers between memory and disk are performed a ____.
:
           
a)        block at a time
           
b)        sector at a time
           
c)         file at a time
           
d)        byte at a time

Question 8
Which of the following is the simplest method for implementing a directory?
           
a)        linear list
           
b)        nonlinear list
           
c)         hash table
           
d)        tree data structure

Question 9 A unified buffer cache uses the same cache for ordinary disk I/O as well as memory-mapped I/O.
            a) True
            b) False

Question 10
Linked allocation suffers from external fragmentation.
:
            a) True
            b) False

Question 11
Which algorithm is considered reasonable for managing a buffer cache?
           
a)        most-recently-used
           
b)        least-frequently-used (LFU)
           
c)         least-recently-used (LRU)
           
d)        first-in-first-out (FIFO)

Question 12
Indexed allocation may require substantial overhead for its index block.
            a) True
            b) False

Question 13
In the Linux VFS architecture, a(n) ____ object represents an individual file.
           
a)        file
           
b)        dentry
           
c)         inode
           
d)        superblock

Question 14
______ includes all of the file system structure, minus the actual contents of files.
           
a)        Logical file system
           
b)        Basic file system
           
c)         Metadata
           
d)        File-organization module

Question 15 NFS views a set of interconnected workstations as a set of ____.
a)        independent machines with dependent file systems
           
b)        independent machines with independent file systems
           
c)         dependent machines with independent file systems
           
d)        dependent machines with dependent file systems

Chapter 13 I/O systems

Question 1 

A(n) ____ is a front-end processor that multiplexes the traffic from hundreds of remote terminals into one port on a large computer. (Full9,Ch13,CG4)
a) 
I/O channel

b) 
network daemon

c) 
terminal concentrator

d) 
context switch coordinator

Question 2 

The ____ register of an I/O port can be written by the host to start a command or to change the mode of a device. (Full9,Ch13,CG4)
a) 
status

b) 
data-in

c) 
control

d) 
transfer

Question 3 

A character-stream device ____
a) 
transfers data in blocks of bytes

b) 
is similar to a random access device

c) 
transfers data a byte at a time

d) 
is a device such as a disk drive

Question 4 

DMA controllers ____. (Full9,Ch13,CG4)
a) 
can steal memory access cycles from the main CPU

b) 
can access main memory at the same time as the main CPU

c) 
do not utilize an additional, special purpose, processor

d) 
are a nonstandard component in PCs of today

Question 5 

A dedicated device cannot be used concurrently by several processes or threads. (Full9,Ch13,CG4)
a) True

b) False

Question 6 

Although caching and buffering are distinct functions, sometimes a region of memory can be used for both purposes. (Full9,Ch13,CG4)
a) True

b) False

Question 7 

A(n) ____ is a buffer that holds output for a device that cannot accept interleaved data streams. (Full9,Ch13,CG4)
a) 
escape

b) 
block device

c) 
cache

d) 
spool

Question 8 

A maskable interrupt can never be disabled. (Full9,Ch13,CG4)
a) True

b) False

Question 9 

An expansion bus is used to connect relatively high speed devices to the main bus. (Full9,Ch13,CG4)
a) True

b) False

Question 10 

____ I/O accesses a block device as a simple array of blocks. (Full9,Ch13,CG4)
a) 
Raw

b) 
Indirect

c) 
Cooked

d) 
Stream

Question 11 

Which of the following is true of a blocking system call? (Full9,Ch13,CG4)
a) 
The execution of the application is suspended when the call is issued.

b) 
The call returns immediately without waiting for the I/O to complete.

c) 
The application continues to execute its code when the call is issued.

d) 
Blocking application code is harder to understand than nonblocking application code

Question 12 

An interrupt priority scheme can be used to ____. (Full9,Ch13,CG4)
a) 
make it possible for high-priority interrupts to preempt the execution of a low priority interrupt (option 2)

b) 
defer the handling of low-priority interrupt without masking off all interrupts (option 3)

c) 
All of the options (option 1 or option 2 or option 3)

d) 
allow the most urgent work to be finished first (option 1)

Question 13 

A sense key reports on the failure of a SCSI device by ____. (Full9,Ch13,CG4)
a) 
maintaining internal pages of error-log information

b) 
stating the general nature of the failure

c) 
stating the general category of failure

d) 
giving detailed information about the exact cause of failure

Question

Vectored I/O allows one system call to perform multiple I/O operations involving a single location. (Full9,Ch13,CG4)
a) True

b) False

Question 15 

STREAMS I/O is asynchronous except when the user process communicates with the stream head. (Full9,Ch13,CG4)
a) True

b) False

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)