Final Exam Flashcards
True or False: As a concept, virtual machines can exist outside and inside the operating system.
False
True or False: We do not need hardware and software to be able to store data persistently
False
Each process accesses its own private: Select one: a. Virtual machine b. Virtual source code c. Virtual address space d. Virtual client
Virtual address space
Why did Linus Torvalds borrow UNIX concept, but not the code? Select one: a. Too complex b. Non-existent c. Too insecure d. Legal reasons
Legal reasons
True or False: When a program runs, the primary goal is to make the system easy to use.
True
Memory is just an array of bytes; to read memory, one must specify \_\_\_\_\_\_\_ to be able to access the data stored there. Select one: a. Location b. Address c. Structure d. The Byte
Address
True or False: Programs are always accessing memory.
True
A running program does the following: Select one: a. Executes code b. Executes instructions c. Executes commands d. Executes source code
Executes instructions
To write (or update) memory, one must also specify \_\_\_\_\_\_ to be written to the given address? Select one: a. Library b. Address c. The data d. Thread
The data
What other name is an OS sometimes called: Select one: a. Resource manager b. Administrator c. Executor d. Master Control Program
Resource manager
True or False: PIDS are used to name processes in the UNIX O/S.
True
True or False: The process list is a data structure.
True
The Windows CreateProcess() system call creates a new process. What is the equivalent system call in UNIX: Select one: a. NTCreateProcess() b. process() c. fork() d. getpid()
fork()
The process states include all of the following except: Select one: a. Blocked b. Stopped c. Ready d. Running
stopped
What technique uses the OS to create an illusion by virtualizing the CPU and running one process, then stopping it and running another? Select one: a. Virtualization b. Context switch c. Scheduling d. Time sharing
Time sharing
What system call is used to send signals to a process, including directives to go to sleep, or die: Select one: a. API b. fork() c. kill () d. wait ()
kill()
A parent can be made to wait for a child process to finish what it has been doing by which command? Select one: a. PID b. Hello World c. Prompt > d. wait() system call
wait() system call
In early (or simple) operating systems, the loading process is done: Select one: a. One at a time b. Eagerly c. In groups d. At compile time
Eagerly
True or False: The natural counterpart of time sharing is space sharing, where a resource is divided (in space) among those who wish to use it.
True
Which of the following statements is incorrect?
Select one:
a. An operating system provides an environment for the execution of programs.
b. An operating system manages system resources.
c. Operating systems provide both command line as well as graphical user interfaces.
d. Operating systems must provide both protection and security.
Operating systems provide both command line as well as graphical user interfaces.
True or False: The shell is just a user program.
True
A process may transition to the Ready state by which of the following actions? Select one: a. Completion of an I/O event b. Awaiting its turn on the CPU c. Newly-admitted process d. All of the above
All of the above
All of the following are Machine States except: Select one: a. Address space b. Registers c. Memory d. API
API
This system call is useful when you want to run a program that is different from the calling program: Select one: a. API b. fork() c. exec() System Call d. wait ()
exec() System Call
\_\_\_\_\_ provide(s) an interface to the services provided by an operating system. Select one: a. Shared memory b. System calls c. Simulators d. Communication
System calls
True or False: Application programmers typically use an API rather than directory invoking system calls.
True
True or False: A running program is not a process.
False
True or False: The register context will not hold the contents of its registers.
False
True or False: UNIX pipes are implemented with the execvp() system call. This is where the output of one process seamlessly is used as input to the next, and long and useful chains of commands can be strung together.
False
True or False: MenuMeters (from Raging Menace software) runs on our PC toolbars.
False
True or False: Address space can be shared or dedicated to users.
True
If a programmer prints out the address of a program its always? Select one: a. Physical b. Combination c. Virtual d. Single
Virtual
True or False: A dual-core system requires each core has its own cache memory.
False
What is a fundamental problem of MQMS: Select one: a. Scalability b. Locking c. Load Imbalance d. Migration
Load Imbalance
True or False: Multithreaded applications can spread work across multiple CPUs and thus run faster when given more CPU resources.
True
True or False: The multiple-queue approach (MQMS) scales better than the single-queue approach (SQMS).
True
True or False: Adding more CPUs will make a single application run faster.
False
True or False: Multicore processors contain one CPU cores on a single chip.
False
The fundamental difference between single-CPU hardware and multi-CPU hardware? Select one: a. Temporal Locality b. Spatial Locality c. Caches d. Time sharing
Caches
True or False: Interactivity refers to single users on the same system
False
True or False: Cache coherency involves ensuring that multiple caches store the most updated version of the stored data.
True
True or False: If you have a single CPU, hardware caches will help the processor run programs faster.
True
Putting all jobs that need to be scheduled into a single queue is called:
Select one:
a. Single queue multiprocessor scheduling
b. Single queue multilocking scheduling
c. Single queue multi scheduling
d. None of the Above
Single queue multiprocessor scheduling
\_\_\_\_\_\_\_\_\_\_ is when each cache pays attention to memory updates by observing the bus that connects them to main memory. When a CPU then sees an update for a data item it holds in its cache, it will notice the change and either invalidate its copy or update it. Select one: a. Cache Coherence b. Bus Snooping c. Lock-free d. Locality
Bus Snooping
The address can be used by all of the following except: Select one: a. Heap b. Program code c. Registers d. None
Registers
Cache Affinity means run process on: Select one: a. Same CPU b. Different CPU c. Multiple CPU’s d. One CPU
Same CPU
Which of the following statements are false with regards to the Linux CFS scheduler?
Select one:
a. Each task is assigned a proportion of CPU processing time.
b. Lower numeric values indicate higher relative priorities.
c. There is a single, system-wide value of vruntime.
d. The scheduler doesn’t directly assign priorities.
There is a single, system-wide value of vruntime.
What technique is used to prevent threads from removing the same head element? Select one: a. Locking b. Threading c. Mutex d. Sychronization
Locking
Load imbalance can be handled by: Select one: a. Multiple queues b. Multiple CPUs c. Migration d. Work stealing
Migration
Which is not a goal of virtual memory (VM)? Select one: a. Protect b. Efficient c. Transparent d. Isolation
Isolation
A(n) \_\_\_\_\_\_ matches the process with each entry in the TLB. Select one: a. address-space identifier b. process id c. stack d. page number
address-space identifier
With segmentation, a logical address consists of \_\_\_\_\_. Select one: a. segment number and offset b. segment name and offset c. segment number and page number d. segment table and segment number
segment number and offset
Segment Base Size
Code 32k 2k
Heap 34k 2k
Stack 28k 2k
True or False: calloc() allocates memory and also zeroes it before returning.
True
True or False: The stack has been relocated to physical address 28KB in the diagram, but with one important difference: it grows forward in physical memory.
False
True or False: A base register is used to transform physical addresses (generated by the program) into virtual addresses.
False
\_\_\_\_\_\_\_ occurs when you forget to free memory. Select one: a. Memory leak b. Memory loss c. Memory block d. None of the above
Memory leak
Internal fragmentation means:
Select one:
a. Space inside the allocated unit is not all used but fragmented
b. Space inside the allocated unit is unfragmented
c. Space inside the allocated unit is all used but fragmented
d. Space inside the allocated unit is not unfragmented
Space inside the allocated unit is not all used but fragmented
When free space gets chopped into little pieces of different sizes and is thus fragmented. Select one: a. Splitting b. Internal fragmentation c. Coalescing d. External fragmentation
External fragmentation
Consider a 32-bit address for a two-level paging system with an 8 KB page size. The outer page table has 1024 entries. How many bits are used to represent the second level page table? Select one: a. 10 b. 8 c. 12 d. 9
9
The data structure free list is used to track?
Select one:
a. Ranges of the virtual memory which is not currently in use
b. Ranges of the physical memory which is currently in use
c. Ranges of the physical memory which is not currently in use
d. Ranges of the virtual memory which is currently in use
Ranges of the physical memory which is not currently in use
Which is not a common error?
Select one:
a. Freeing memory before you are done with it
b. Forgetting to initialize allocated memory
c. Forgetting to allocate memory
d. All are common errors
All are common errors
Which of the following data structures is appropriate for placing into its own segment? Select one: a. heap b. kernel code and data c. user code and data d. all of the above
all of the above
Given the logical address 0xAEF9 (in hexadecimal) with a page size of 256 bytes, what is the page offset? Select one: a. 0xAE b. 0xF9 c. 0xA d. 0xF900
0xF9
Which of the following techniques are correct for physical address?
Select one:
a. Physical address = virtual address + translation
b. Physical address = virtual address + bounds
c. Physical address = virtual address + limits
d. Physical address = virtual address + base
Physical address = virtual address + base
To save memory, sometimes it is useful to share certain memory segments between address spaces. This is called: Select one: a. Code swapping b. Code sharing c. Address sharing d. Address swapping
Code sharing
Assume the value of the base and limit registers are 1200 and 350 respectively. Which of the following addresses is legal? Select one: a. 355 b. 1200 c. 1551 d. all of the above
1200
What is used to free heap memory no longer in use. Select one: a. The malloc() Call b. Stack c. The free() Call d. Automatic
The free() Call
These instructions will store the value of eax to at the end of the program:
128: movl 0x0(%ebx), %eax ;load 0+ebx into eax
132: addl $0x03, %eax ;add 3 to eax register
135: movl %eax, 0x0(%ebx) ;store eax back to mem
Select one:
a. Different memory location
b. Multiple locations
c. Same memory location
d. One location
Same memory location
Basic strategies to memory allocates does not include: Select one: a. Worst Fit b. Last Fit c. Best Fit d. First Fit
Last Fit
True or False: A base register is used to transform physical addresses (generated by the program) into virtual addresses.
False
Which algorithm is considered reasonable for managing a buffer cache? Select one: a. least-recently-used (LRU) b. first-in-first-out (FIFO) c. most-recently-used d. least-frequently-used (LFU)
least-recently-used (LRU)
True or False: A dual-core system requires each core has its own cache memory.
False
Segment Base Size Code 32K 2K Heap 34K 2K Stack 28K 2K
Figure 16.3: Segment Register Values
True or False: The stack has been relocated to physical address 28KB in the diagram above, but with one important difference: it grows forward in physical memory
False
\_\_\_\_\_ is not a technique for passing parameters from an application to a system call Select one: a. Cache memory b. Registers c. Stack d. Special block in memory
Cache memory
True or False: The page selection policy only determines which page to swap not when to swap pages.
False
True or False: The page-replacement policy means that pages are not placed to make more space.
False
Swap space is used for: Select one: a. Memory overlays b. Stack overflows c. Swapping pages d. Saving space on hard disk drives
Swapping pages
Two important design issues for cache memory are \_\_\_\_ Select one: a. speed and volatility. b. size and replacement policy. c. power consumption and reusability. d. size and access privileges.
size and replacement policy
Optimal page replacement ____.
Select one:
a. is the page-replacement algorithm most often implemented
b. is used mostly for comparison with other page-replacement schemes
c. can suffer from Belady’s anomaly
d. requires that the system keep track of previously used pages
is used mostly for comparison with other page-replacement schemes
Using the LRU policy which page will be evicted first? Access Hit/Miss? Evict Cache State 0 Miss LRU! 0 1 Miss LRU! 0, 1 2 Miss LRU! 0, 1, 2 0 Hit LRU! 1, 2, 0 1 Hit LRU! 2, 0, 1 3 Miss 2 LRU! 0, 1, 3 0 Hit LRU! 1, 3, 0 3 Hit LRU! 1, 0, 3 1 Hit LRU! 0, 3, 1 2 Miss 0 LRU! 3, 1, 2 1 Hit LRU! 3, 2, 1
Select one:
a. 2 Miss LRU! 0, 1, 2
b. 3 Miss 2 LRU! 0, 1, 3
c. 3 Hit LRU! 1, 0, 3
d. 1 Hit LRU! 3, 2, 1
3 Miss 2 LRU! 0, 1, 3
Chociaż wydaje mi sie ze jest 1 Hit LRU! 3, 2, 1
Swap space management ____.
Select one:
a. is a high-level operating system task
b. tries to provide the best throughput for the virtual memory system
c. is primarily used to increase the reliability of data in a system
d. None of the above
tries to provide the best throughput for the virtual memory system
Which of the following is not a reason explaining why mobile devices generally do not support swapping?
Select one:
a. Limited space constraints of flash memory.
b. Small size of mobile applications do not require use of swap space
c. Limited number of writes of flash memory.
d. Poor throughput between main memory and flash memory
Small size of mobile applications do not require use of swap space
Given the reference string of page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 4 and a system with three page frames, what is the final configuration of the three frames after the LRU algorithm is applied? Select one: a. 1, 3, 4 b. 3, 1, 4 c. 4, 1, 2 d. 1, 2, 3
3, 1, 4
In figure 20.1 which block is the next free space for allocation? Select one: a. Block 3 b. PFN 0 c. PFN 3 d. Block 2
Block 2
The only free one
\_\_\_\_\_ is the algorithm implemented on most systems. Select one: a. FIFO b. Least frequently used c. Most frequently used d. LRU
LRU
Using the FIFO policy which page will be evicted first? Access Hit/Miss? Evict Cache State 0 Miss First-in! 0 1 Miss First-in! 0, 1 2 Miss First-in! 0, 1, 2 0 Hit First-in! 0, 1, 2 1 Hit First-in! 0, 1, 2 3 Miss 0 First-in! 1, 2, 3 0 Miss 1 First-in! 2, 3, 0 3 Hit First-in! 2, 3, 0 1 Miss 2 First-in! 3, 0, 1 2 Miss 3 First-in! 0, 1, 2 1 Hit First-in! 0, 1, 2 Select one: a. 1 Miss 2 First-in! 3, 0, 1 b. 2 Miss 3 First-in! 0, 1, 2 c. 3 Miss 0 First-in! 1, 2, 3 d. 0 Miss 1 First-in! 2, 3, 0
3 Miss 0 First-in! 1, 2, 3
What happens if line number 2 is false and 3 is true? PFN = FindFreePhysicalPage() 2 if (PFN == -1) // no free page found 3 PFN = EvictPage() // run replacement algorithm 4 DiskRead(PTE.DiskAddr, pfn) // sleep (waiting for I/O) 5 PTE.present = True // update page table with present 6 PTE.PFN = PFN // bit and translation (PFN)
Select one:
a. Check for any free pages
b. Check for free space
c. Will not page in desired pages
d. Page in desired page
Page in desired page
The OS decides which page (or pages) to evict from memory by following some general principles, which is not?
Select one:
a. Ranges of the virtual memory which is not currently in use
b. Using History: LRU
c. Average memory access time (AMAT)
d. Cache Management
Average memory access time (AMAT)
Which of the following statements is false?
Select one:
a. Swapping works in conjunction with virtual memory techniques.
b. Some systems allow for multiple swap spaces (disks).
c. Solaris only swaps pages of anonymous memory.
d. Typically, entire processes are swapped into memory.
Typically, entire processes are swapped into memory.
Channel logging tokens can be set to all but: Select one: a. Relaxed b. Strict c. Both versions d. None
Both versions
Computers not joined to the domain can use event forwarding in conjunction with: Select one: a. HTTP b. WinRM c. HTTPS d. SSL/TLS
SSL/TLS
True or False: Collected events are almost always malicious.
False
True or False: The Windows operating system has a built-in network based firewall.
False
For Windows Defender event ID 3002 means? Select one: a. Action on malware failed b. Failed to update signatures c. Real time protection failed d. Unexpected error
Real time protection failed
True or False: Mobile devices create a log whenever they enter and leave a wireless network.
True
True or False: The event log file is set to 1G of storage and one should overwrite it rather than allocate more space or start a new log file of 1G.
False
This command “winrm id –remote:TARGET” will: Select one: a. Locates TARGET Machine b. Enumerate all listeners c. Identifies remote machine TARGET d. Identifies TARGET machine
Identifies remote machine TARGET
When troubleshooting the target machine the local host name should be set to: Select one: a. Local host b. Remote: c. TARGET d. Local machine
TARGET
In the process of application whitelisting events are collected for all except: Select one: a. Application whitelisting b. Applocker c. Blocked applications d. EMET
EMET
The following are all assumptions about processes except:
Select one:
a. Each job runs for the same amount of time
b. All jobs arrive at the same time
c. All jobs only use the CPU (i.e., they perform no I/O)
d. The run-time of each job is not known
The run-time of each job is not known
Return-from-trap instruction returns into the calling user program while simultaneously reducing the privilege level back to \_\_\_\_\_\_\_\_ Select one: a. User mode b. Kernel mode c. OS mode d. CPU mode
User mode
Basic algorithm for scheduling include all but:
Select one:
a. Shortest Time-to-Completion Last (STCL)
b. First Come, First Served (FCFS)
c. Shortest Job First (SJF)
d. First Out (FIFO)
Shortest Time-to-Completion Last (STCL)
Allows the kernel to carefully expose certain key pieces of functionality to user programs? Select one: a. user mode b. system call c. kernel mode d. trap
system call
True or False: The process list a data structure.
True
True or False: Direct execution refers to running a program directly on the CPU.
True
The \_\_\_\_\_ scheduler allocates available memory to each process using a percentage. Select one: a. Equal b. Global c. Fair-Share d. Slab
Fair-Share
True or False: Ticket inflation is when a process can temporarily only raise the number of tickets it owns.
False
True or False: Timesharing means the operating system shares the physical CPU among many jobs running one at a time.
True
Basic algorithms for scheduling include all but:
Select one:
a. Shortest Time-to-Completion Last (STCL)
b. First Come, First Served (FCFS)
c. Shortest Job First (SJF)
d. First Out (FIFO)
Shortest Time-to-Completion Last (STCL)
True or False: Turnaround time is defined as is the total time taken between the submission of a program/process/thread/task for execution and the return of the complete output to the customer/user.
True
Processes running in the system are sometimes called workload
True/False
True
True or False: Turnaround time is defined as the time at which the job finally completes minus the time at which the job arrived in the system.
Tturnaround = Tcompletion - Tarrival
True
The term random-access memory or RAM means that:
Select one:
a. Memory is dynamically accessed Incorrect
b. Memory is randomly accessed
c. RAM is hard to gauge
d. Memory is not random
Memory is randomly accessed
True or False: Internal fragmentation happens when big pages waste space within each page.
True
True or False: Paging introduces a problem that page tables are too big and thus consume too much memory
True
Single larger pages of 4 MB or more are commonly used for applications such as: Select one: a. Programs b. Memory management systems c. Data base systems d. Reserachers
Data base systems
Virtual page numbers and page off sets are used to:
Select one:
a. Track RAM usage
b. Store memory values
c. Translate virtual addresses to physical memory addresses
d. Store RAM values
Translate virtual addresses to physical memory addresses
True or False: Implementing paging support without care will lead to a faster machine.
False
Consult the following figure; which page frame will be used first? Select one: a. Page frame 1 b. Page frame 2 c. Page frame 3 d. Page frame 4
Page frame 3
True or False: A 32-bit logical address with 8 KB page size will have 1,000,000 entries in a conventional page table?
False
True or False: There are usually two types of locality, temporal and spatial
True
True or False: Fragmentation does not occur in a paging system.
False
True or False: The Event Viewer allows users to create custom views that organize event data based on a custom filter.
True
