CSC 415 Operating Systems All Units
iOS is open source, Android is closed source. Select one: a. False b. True
a. False
Is an extension a part of a file name? Select one: a. True b. False
a. True
Sharing of memory-mapped sections of memory among multiple processes can be efficiently realized without the usage of virtual memory: Select one: True False
False
Source files are compiled into object file(s) which use absolute addresses. Select one: True False
False
Standard swapping involves swapping in pages of processes instead of entire processes. True False
False
The addresses of a given number of free blocks can be found faster using linked list rather than using grouping. Select one: a. True b. False
b. False
The communication with named pipes requires parent-child relationship. Select one: a. True b. False
b. False
The exec() system call creates a new process. Select one: a. True b. False
b. False
Vectored IO allows one system call to perform multiple IO operations involving a single location. Select one: a. True b. False
b. False
When fork() is invoked, it is passed a set of flags that determine how much sharing is to take place between the parent and child tasks. Select one: a. True b. False
b. False
create() system call uses open-file table. Select one: a. True b. False
b. False
System call interface is the boundary between user programs and operating system services. Select one: a. No b. Yes
b. Yes
The dirty (modify) bit identifies Select one: a. a page that has been corrupted. b. a page that has been modified since it was loaded. c. a page that needs to be reloaded when accessed. d. a page that is shared by multiple processes.
b. a page that has been modified since it was loaded.
Memory compression is faster than swapping pages to hard disks, but slower than swapping pages to SSDs. True False
False
Monitors are a theoretical concept and are not practiced in modern programming languages Select one: True False
False
Non-uniform memory access has little effect on the performance of a virtual memory system. True False
False
On a read operation, the device driver first checks if the data already available in the buffer cache. Select one: True False
False
On systems that provide it, vfork() should always be used instead of fork(). True False
False
Only a fraction of a process's working set needs to be stored in the TLB. True False
False
Performance of allocation method is determined only by the used allocation algorithm: Select one: True False
False
Professor Bierman clearly hates this area of operating systems. Select one: True False
False
Raw disk contains a file system. Select one: True False
False
Shared memory is a more appropriate IPC mechanism than message passing for distributed systems. Select one: True False
False
System calls can be run in either user mode or kernel mode. Select one: True False
False
System programs all run in kernel mode. Select one: True False
False
The content of an immutable file can be changed. Select one: True False
False
The main drawback of General Graph Directory is performance overhead from possibility of traversing shared files multiple times: Select one: True False
False
There is only a single flavor of shells for users to choose. Select one: True False
False
Threads, unlike forked processes, share a stack. Select one: True False
False
Tools for operating system debugging must be system-wide. Select one: True False Feedback
False
Traditional synchronization is always much faster than CAS-based synchronization. Select one: True False
False
Truncating a file creates a copy of existing file with length attribute set to 0 and deletes the old file: Select one: True False
False
Virtual file system does not distinguish local files from remote ones. Select one: True False
False
When a layered structure is used for file-system implementation, risk of duplication of code increases:
False
When the owner of a mutex lock invokes pthread mutex unlock(), all threads blocked on that mutex's lock are unblocked. Select one: True False
False
Server of NFS (Network File System) version 3 is stateful Select one: True False
False It is version 4 that implemented a stateful system, version 3 is stateless.
Providing a preemptive, priority-based scheduler guarantees hard real-time functionality. Select one: a. False b. True
a. False
Sequential access to a file is based on a disk model of a file. Select one: a. False b. True
a. False
Solaris uses both a local and global page replacement policy. Select one: a. False b. True
a. False
Some operating systems keep a pool of free frames so that the frequency of page faults is lowered. Select one: a. False b. True
a. False
Storage devices that do not allow overwrite (such as NVM devices) need only the free list for managing free space. Select one: a. False b. True
a. False
The difference between a program and a process is that a program is an active entity while a process is a passive entity. Select one: a. False b. True
a. False
The length of a time quantum assigned by the Linux CFS scheduler is dependent upon the relative priority of a task. Select one: a. False b. True
a. False
The single benefit of a thread pool is to control the number of threads. Select one: a. False b. True
a. False
Truncating a file operation resets values of all its attributes and releases its file space. Select one: a. False b. True
a. False
Windows uses both a local and global page replacement policy. Select one: a. False b. True
a. False
Solaris ZFS file system never overwrites blocks with new data. Select one: a. False b. True
a. False (According to the textbook, I thought it was True)
Which of the following is true of compaction? Select one: a. It is possible only if relocation is dynamic and done at execution time. b. It can be done at assembly, load, or execution time. c. It cannot shuffle memory contents. d. It is used to solve the problem of internal fragmentation.
a. It is possible only if relocation is dynamic and done at execution time.
_____ is the algorithm implemented on most systems. Select one: a. LRU b. Least frequently used c. Most frequently used d. FIFO
a. LRU
An operating system may provide: Select one: a. Many general-purpose file systems and one special-purpose file system b. Only one special-purpose file system c. Only one general-purpose file system and one special-purpose file system d. Only one general-purpose file system
a. Many general-purpose file systems and one special-purpose file system
_____ allows operating system services to be loaded dynamically. Select one: a. Modules b. File systems c. Graphical user interfaces d. Virtual Machines
a. Modules
On UNIX, the setuid attribute on a program causes that program to run with the user ID of the current user's ID. Select one: a. No b. Yes
a. No
Which of the following is NOT true for Peterson's solution? Select one: a. Peterson's solution works for synchronization among more than two processes b. The progress requirement is satisfied c. The bounded-waiting requirement is met d. Mutual exclusion is preserved
a. Peterson's solution works for synchronization among more than two processes
The ____ scheduling algorithm is designed especially for time-sharing systems. Select one: a. RR b. FCFS c. Multilevel queue d. SJF
a. RR
____ I/O accesses a block device as a simple array of blocks. Select one: a. Raw b. Cooked c. Stream d. Indirect
a. Raw
____ scheduling is approximated by predicting the next CPU burst with an exponential average of the measured lengths of previous CPU bursts. Select one: a. SJF b. FCFS c.Multilevel queue d. RR
a. SJF
Which of the following is not a reason explaining why mobile devices generally do not support swapping? Select one: a. Small size of mobile applications do not require the use of swap space. b. Limited space constraints of flash memory. c. Limited number of writes of flash memory. d. Poor throughput between main memory and flash memory.
a. Small size of mobile applications do not require the use of swap space.
The ________ provides a portion of the system call interface for UNIX and Linux. Select one: a. Standard C library b. Java c. Standard API d. POSIX
a. Standard C library
Check all the answers that are correct ways of interfacing with the kernel from the user application. Select one or more: a. System Calls b. By escalating privileges c. Calling Interrupts d. Jumping directly to the Kernel e. Writing data to Kernel Memory
a. System Calls
In the video, Professor Bierman explains the older Intel architecture that had a 16 bit segment register and a 16 bit address register. Check all the statements below that are true. Select one or more: a. The segment register's reference memory on even 16 byte boundries. b. The total of the address space of the segment register and the address register was 20 bits. c. The total of the address space of the segment register and the address register was 24 bits. d. The segmentation of memory was hard to understand even for programmers of the time using it. e. The total of the address space of the segment register and the address register was 32 bits.
a. The segment register's reference memory on even 16 byte boundries. b. The total of the address space of the segment register and the address register was 20 bits. d. The segmentation of memory was hard to understand even for programmers of the time using it.
Which of the following is FALSE about reapers? Select one: a. They may swap out pages event when there are ample free frames available. b. They may swap out a page from a process even when that process is not running. c. They may use any page replacement algorithm to swap out pages. d. They implement a global page replacement policy.
a. They may swap out pages event when there are ample free frames available.
13.Systems that do not permit access to the files of another user do not need protection Select one: a. True b. False
a. True
A dedicated device cannot be used concurrently by several processes or threads. Select one: a. True b. False
a. True
A disk drive may have many partitions each of which contains a different file system. Select one: a. True b. False
a. True
A multicore system allows two (or more) threads that are in compute cycles to execute at the same time. Select one: a. True b. False
a. True
All file systems suffer from internal fragmentation. Select one: a. True b. False
a. True
All operating systems have to support at least one file structure. Select one: a. True b. False
a. True
All processes in UNIX first translate to a zombie process upon termination. Select one: a. True b. False
a. True
An I/O system call returns a one-bit information about the status of the call. Select one: a. True b. False
a. True
An NFS (Network File System) is building on a RPC (Remote Procedure Call) system. Select one: a. True b. False
a. True
Background processes are not apparent to users. Select one: a. True b. False
a. True
Contiguous allocation of a file is defined by the address of the first block and length (in block units) of the file. Select one: a. True b. False
a. True
Every object in Java has associated with it a single lock. Select one: a. True b. False
a. True
Hashed page tables are commonly used when handling addresses larger than 32 bits. Select one: a. True b. False
a. True
In general, SCAN disk head scheduling will involve less movement of the disk heads than C-SCAN disk head scheduling. Select one: a. True b. False
a. True
In two-level directory structure, the system's master file directory (MFD) is searched when a user logs in. Select one: a. True b. False
a. True
Mac OS X is a hybrid system consisting of both the Mach microkernel and BSD UNIX. Select one: a. True b. False
a. True
Many operating system merge I/O devices and files into a combined file because of the similarity of system calls for each. Select one: a. True b. False
a. True
One important principle is the separation of policy from mechanism. Select one: a. True b. False
a. True
Reading and writing a file operations use the same current-file-position pointer. Select one: a. True b. False
a. True
Round-robin (RR) scheduling degenerates to first-come-first-served (FCFS) scheduling if the time quantum is too long. Select one: a. True b. False
a. True
Semaphore implementation overcomes the busy waiting problem. Select one: a. True b. False
a. True
Solid state disks (SSDs) commonly use the FCFS disk scheduling algorithm. Select one: a. True b. False
a. True
Solid state disks are generally faster than magnetic disks. Select one: a. True b. False
a. True
Stack algorithms can never exhibit Belady's anomaly. Select one: a. True b. False
a. True
The ARM architecture uses both single-level and two-level paging. Select one: a. True b. False
a. True
The FAT method incorporates free-block accounting into the allocation data structure. Select one: a. True b. False
a. True
The I/O control level consists of device drivers and interrupt handlers to transfer information between the main memory and the disk system Select one: a. True b. False
a. True
The buddy system for allocating kernel memory is very likely to cause fragmentation within the allocated segments. Select one: a. True b. False
a. True
The file allocation table (FAT) has one entry for each block and is indexed by block number. Select one: a. True b. False
a. True
The instruction that causes a page fault needs to be re-executed after the fault has been handled. Select one: a. True b. False
a. True
There is no universally accepted definition of an operating system. Select one: a. True b. False
a. True
Virtually all modern operating systems provide support for SMP Select one: a. True b. False
a. True
Windows 7 User-mode scheduling (UMS) allows applications to create and manage thread independently of the kernel Select one: a. True b. False
a. True
On a system with pure demand-paging, a process will experiece a high page fault rate when the process begins execution. Select one: a. True, because no pages are loaded in memory b. False, because the program is already loaded c. False, because it is unknown how much physical memory is available and there might not be a need for paging. d. True, because all programs have a high page fault on loading
a. True, because no pages are loaded in memory
Which of the following is true of earliest-deadline-first (EDF) scheduling algorithm? Select one: a. When a process becomes runnable, it must announce its deadline requirements to the system. b. Deadlines are assigned as following: the earlier the deadline, the lower the priority; the later the deadline, the higher the priority. c. It assigns priorities statically according to deadline. d. Priorities are fixed; that is, they cannot be adjusted when a new process starts running.
a. When a process becomes runnable, it must announce its deadline requirements to the system.
A system call runs in kernel mode only. Select one: a. Yes b. No
a. Yes
VMware is a virtual machine manager when it manages guest operating systems. Select one: a. Yes b. No
a. Yes
A drawback of equal or proportional allocation is that Select one: a. a high-priority process is treated the same as a low-priority process. b. the allocation varies according to the degree of multiprogramming. c. the processes that arrive earlier get more pages than the processes arriving later. d. they are very expensive to compute.
a. a high-priority process is treated the same as a low-priority process.
In a multithreaded server architecture, which of the following is used to service a new user request? Select one: a. a new created thread b. a new created process c. none of the other answers d. the same process for prior users
a. a new created thread
A page-table base register stores Select one: a. a pointer to the page table in memory. b. the page size of the page currently being accessed. c. the starting physical address of the frame currently being addressed. d. the starting logical address of the page currently being accessed.
a. a pointer to the page table in memory.
What causes a lack of support for efficient direct (random) access in linked allocation: Select one: a. absence of FAT b. internal fragmentation c. declaration problems d. external fragmentation
a. absence of FAT
What is the correct order of operations for protecting a critical section using mutex locks? Select one: a. acquire() followed by release() b. wait() followed by signal() c. signal() followed by wait() d. release() followed by acquire()
a. acquire() followed by release()
What steps are necessary to create a file? Select one: a. all of the other answers b. none of the other answers c. allocating a space in the file system d. making an entry for the file in the directory
a. all of the other answers
Which of the following cases could force a process removed from the CPU? Select one: a. all of the other answers b. fork a child c. interrupt or time slice expired d. I/O request
a. all of the other answers
Which of the following is TRUE about managing defective blocks? Select one: a. all of the other answers. b. Low level formatting can set aside spare sectors not visible to the operating system. c. Controllers can be instructed to replace a bad block by moving all sectors following the defective sector one sector forward until a spare sector is reached. d. Defective blocks can be handled by OS by ensuring that the file system doesn't allocate those blocks.
a. all of the other answers.
UNIX systems allow groups to be created and modified by: Select one: a. any superuser b. any owner of the file c. automatic privilege determination procedures d. any member of the group
a. any superuser
Which of the following defines the view of the operating system seen by most users? Select one: a. application and system programs b. library calls c. system calls d. device drivers
a. application and system programs
Signals can be emulated in windows through ____. Select one: a. asynchronous procedure calls b. remote procedure calls c. local procedure calls d. none of the other answers
a. asynchronous procedure calls
Pthreads can be implemented Select one: a. at the user level or inside the operating system kernel b. only at the user level c. only inside the operating system kernel d. only Windows OS
a. at the user level or inside the operating system kernel
In the case of UNIX, where sharing is implemented by symbolic link________________________ Select one: a. both of the above b. the deletion of link does not affect the original file c. the deletion of the original file does not remove the link, but it is dangling d. none of the other answers
a. both of the above
Which of the following is preemptive? Select one: a. both of the above b. none of the other answers c. rate-monotonic scheduling d. earliest-deadline-first scheduling
a. both of the above
Technique used to improve I/O efficiency by temporarily storing copies of data is called Select one: a. caching. b. spooling. c. buffering. d. memory mapping.
a. caching.
In DMA-based I/O, Select one: a. cycle stealing can slow down the CPU computation, but off-loading the data-transfer work to a DMA controller generally improves the total system performance. b. data is transferred to/from a single block of memory, but not to/from multiple blocks. c. interrupt mechanism is not used. d. CPU is relieved from data transfer and is interrupted after every word has been transferred to initiate the next word transfer.
a. cycle stealing can slow down the CPU computation, but off-loading the data-transfer work to a DMA controller generally improves the total system performance.
The list of processes waiting for a particular I/O device is called a(n) ____. Select one: a. device queue b. standby queue c. interrupt queue d. ready queue
a. device queue
What is a significant drawback of a hash table: Select one: a. fixed size b. difficult insertion and deletion c. dependence on linear list structure d. slow read/write operations
a. fixed size
The advantage of continuous allocation lies in: Select one: a. flexibility b. easy management of memory space c. solving dynamic-storage allocation problem d. low number of required disk seeks
a. flexibility
Windows gives a 3x priority boost to? Select one: a. foreground applications b. interrupt routines c. system functions d. background applications
a. foreground applications
The Windows CreateProcess() system call creates a new process. What is the equivalent system call in UNIX? Select one: a. fork() b. NTCreateProcess() c. process() d. getpid()
a. fork()
Which of the following is nonvolatile? Select one: a. hard-disk drive b. main memory c. register d. cache
a. hard-disk drive
Solaris and Windows assign higher-priority threads/tasks longer time quantums and lower-priority tasks shorter time quantums. Select one: a. True b. False
b. False
Solid state disks are considered volatile storage. Select one: a. True b. False
b. False
The consistency check is always able to recover the structures, e.g., resulting in loss of files and entire directories. Select one: a. True b. False
b. False
The logical file system module includes the free-space manager. Select one: a. True b. False
b. False
The open() call returns a pointer to the appropriate entry in the system wide-open-file table. Select one: a. True b. False
b. False
There is a 1:1 correspondence between the number of entries in the TLB and the number of entries in the page table. Select one: a. True b. False
b. False
Thread-local storage is inherently equivalent to local variables. Select one: a. True b. False
b. False
You can access a file in an unmounted file system. Select one: a. True b. False
b. False
Which of the following is true about dynamic storage allocation? Select one: a. First fit is clearly better than best fit in terms of time and storage utilization. b. First fit requires less time for allocation than worst fit on average. c. Worst fit provides the best storage utilization. d. Best fit is clearly better than first fit in terms of time and storage utilization.
b. First fit requires less time for allocation than worst fit on average.
Where does thread execution begin after calling pthread_create? Select one: a. From the start of main. b. From the start of the function passed into pthread_create c. At the instruction following the call to pthread_create d. From the start of the procedure labeled "thread"
b. From the start of the function passed into pthread_create
When an application over allocates memory the application can cause thrashing. Which application is an example of a program that causes thrashing? Select one: a. Firefox b. Google Chrome c. Apple Safari d. Microsoft Edge
b. Google Chrome
One advantage of HDDs over SSDs is Select one: a. HDDs are more reliable than SSDs. b. HDDs are cheaper per megabyte than SSDs. c. HDDs consume less power than SSDs. d. HDDs are faster than SSDs.
b. HDDs are cheaper per megabyte than SSDs.
Which of the following will trigger an interrupt? Select one: a. CPU execution b. I/O completion c. software execution d. kernel function
b. I/O completion
The process runs with effective UID all the time until the process is stopped. Select one: a. Yes b. No
b. No
If process P0 is switched to process P1, state for P0 will be saved into ____, and state from ___ will be reloaded? Select one: a. PCB1, PCB1 b. PCB0, PCB1 c. PCB1, PCB0 d. PCB0, PCB0
b. PCB0, PCB1
Which of the following is a software-based solution to the critical-section problem? Select one: a. test_and_set b. Peterson's solution c. all of the other answers d. compare_and_swap
b. Peterson's solution
____________ occurs when a higher-priority process needs to access a data structure that is currently being accessed by a lower-priority process. Select one: a. Deadlock b. Priority inversion c. A critical section d. A race condition
b. Priority inversion
____ allows a thread to run on only one processor. Select one: a. Load balancing b. Processor affinity c. NUMA d. Processor Set
b. Processor affinity
Which of these RAID levels is best for storing large volumes of data? Select one: a. RAID levels 0 + 1 and 1 + 0 b. RAID level 5 c. RAID level 3 d. RAID level 4
b. RAID level 5
Shortest-remaining-time-first scheduling is the preemptive version of __________? Select one: a. RR b. SJF c. FCFS d. Multilevel queue
b. SJF
Which of the following is FALSE about swap space use? Select one: a. Swap space may be used to store only pages that have been pushed out of main memory. b. Swap space may be used to store the file system. c. Swap space may be used to hold an entire process image. d. Swap space can be a dedicated swap partition, a swap file, or a combination of swap partitions and swap files.
b. Swap space may be used to store the file system.
What are the consequences of using clusters? Select one: a. They increase the number of blocks to manage and increase the amount of fragmentation b. The decrease the number of blocks to manage but increase internal fragmentation c. They increase the number of blocks to manage and decrease internal fragmentation d. They decrease the number of blocks to manage and decrease internal fragmentation e. They decrease the number of blocks to manage and increase external fragmentation
b. The decrease the number of blocks to manage but increase internal fragmentation
Which of the following statements is false? Select one: a. Mobile devices usually have fewer processing cores than a standard desktop computer. b. The difference in storage capacity between a mobile device and laptop is shrinking. c. Mobile devices must be concerned with power consumption. d. Mobile devices can provide features that are unavailable on desktop or laptop computers
b. The difference in storage capacity between a mobile device and laptop is shrinking.
Touch screen is a user interface on mobile systems. Select one: True False
True
Linux mostly uses atomic integers to manage race conditions within the kernel. Select one: True False
False
Load balancing is typically only necessary on systems with a common run queue. Select one: a. False b. True
a. False
Email is a system service. Select one: True False
False
Given a logical address of 0x8E7 and a page size of 256 bytes and given the page table below, what is the physical address (in hex)? Page TableFrameValidity Bit0x9v0x14v0xAv0x21v0x2v0x7v0xCv0x22v0x24v0x27i0x23v0x1i0i0i0i
0x24E7
Given the logical address 0x89457A7C (in hexadecimal) with a offset (displacement) size of 12 bits, what is the page number (in hex)?
0x89457
Assume a system has a TLB hit ratio of 90%. It requires 15 nanoseconds to access the TLB, and 85 nanoseconds to access main memory. What is the effective memory access time (in nanoseconds) for this system?
108.5 Remember that every memory access is 85 nanoseconds. So it will take at least that long, plus the overhead of the paging table. That is what you want to calculate. With no TLB, then it would be 2 memory accesses of 170 nanoseconds.
Assuming that pages are 128 integers (words) in size, consider the C program to initialize every element of a 128x128 integer array to zero. int i, j; int [128][128] data; for (j = 0; j < 128; j++) for (i = 0; i < 128; i++) data [i] [j] = 0; There will be blank page faults as a result if there is only one frame available. But, changing the last line to blank will result in only blank page faults. Thus it is important for a programmer to understand how memory is laid out.
16,384 data [j] [i] = 0; 128
Given the logical address 0x478D7A5B (in hexadecimal) with a page size of 256 bytes, what is the page offset?
5B
How many bytes are wasted for a file of 2500 bytes assuming blocks are 512 bytes?
60
I/O subsystem is integrated into process manager, memory manager and file system. Select one: True False
False
Which of the following statements is false with regard to Solaris memory management? A) The speed at which pages are examined (the scanrate) is constant. B) The pageout process only runs if the number of free pages is less than lotsfree. C) An LRU approximation algorithm is employed. D) Pages selected for replacement may be reclaimed before being placed on the free list.
A) The speed at which pages are examined (the scanrate) is constant.
The vfork() system call in UNIX ____. A) allows the child process to use the address space of the parent B) uses copy-on-write with the fork() call C) is not intended to be used when the child process calls exec() immediately after creation D) duplicates all pages that are modified by the child process
A) allows the child process to use the address space of the parent
Given the logical address 0x478D7A5B (in hexadecimal) with a offset (displacement) size of 12 bits, what is the page offset?
A5B
Prepaging an executable program is much easier than prepaging a text file. Select one: a. False b. True
a. False
Given the logical address 0xAEF9 (in hexadecimal) with a page size of 256 bytes, what is the page offset? A) 0xAE B) 0xF9 C) 0xA D) 0xF900
B) 0xF9
In Solaris, if an interactive thread with priority 15 uses its entire time quantum, what is its priority recalculated to? A) 51 B) 5 C) 160 D) It remains at 15
B) 5
Windows uses a local page replacement policy _____. A) when a process exceeds its working set minimum B) when a process exceeds its working set maximum C) when the system undergoes automatic working set trimming D) under all circumstances
B) when a process exceeds its working set maximum
In memory compression, A) compression ratio needs to be balanced with the temporary memory needed for compression. B) compression ratio needs to be balanced with the number of pages to be compressed. C) compression ratio needs to be balanced with the compression time. D) compression ratio needs to be balanced with page size.
C) compression ratio needs to be balanced with the compression time.
If Free = 1; The following bit vector represents a disk where blocks 1, 5, 8, 11, 14 are free and the rest allocated - 1011101101101101.... Select one: True False
False
What is the numeric priority of a Windows thread in the HIGH_PRIORITY_CLASS with ABOVE_NORMAL relative priority? A) 24 B) 10 C) 8 D) 14
D) 14
In Linux, A) pages in active list may be moved to inactive list. B) pages in inactive list may be moved to active list. C) pages in inactive list are may be reclaimed for the free list. D) All of the above.
D) All of the above.
If a resource-allocation graph has a cycle, the system must be in a deadlocked state. Select one: True False
False
If the page-fault rate is too high, the process may have too many frames. True False
False
In general, virtual memory decreases the degree of multiprogramming in a system. True False
False
In synchronous writes data is being stored in caches, with caller obtaining the control Select one: True False
False
In the dining philosophers problem, there is a possibility of deadlock but not livelock. Select one: True False
False
It is crucial to the file system to understand the type of a file? Select one: True False
False
Linux distinguishes between processes and threads. Select one: True False
False
A computer system always has one file system. Select one: True False
False
A deadlock-free solution eliminates the possibility of starvation. Select one: True False
False
A new browser process is created by the Chrome browser for every new website that is visited. Select one: True False
False
A policy should be defined together with the mechanism. Select one: True False
False
A statically-linked library is only linked and loaded if it is conditionally required during program runtime.
False
A thread is composed of a thread ID, program counter, register set, and heap. Select one: True False
False
All remote file systems allow clients to mount only one file system from remote machines. Select one: True False
False
An initial bootstrap program is in the form of random-access memory (RAM). Select one: True False
False
An operating system is far easier to port-to move to some other hardware-if it is written in a lower-level language. Select one: True False
False
Any user can always read any file. Select one: True False
False
Applications that are designed to work on one operating system will also work on another operating system as long as they provide the same APIs. Select one: True False
False
As long as the CPU (machine) instructions are the same, an application can run across machines regardless of the operating system. Select one: True False
False
Debugging is the activity of finding and fixing errors in a system, only in software. Select one: True False
False
Double-caching improves the memory usage efficiency and prevents file corruption Select one: True False
False
LBA stands for Local Block Allocation? Select one: True False
False LBA stands for Logical Block Array, and it the virtual array of blocks presented by the Basic File System that represent the volume. We will use the terms Logical Block and Logical Block Array throughout the file system project
Correctly fill in the diagram to show the Linux process memory layout. Linux Process Memory Layout
Kernel Stack || || V Library Mappings /\ || || Heap Uninitialized Data Initialized Data Text Reserved
Correctly label the memory pyramid Top of Pyramid Second layer from tip of Pyramid Second layer from base of Pyramid Bottom of Pyramid
Top of Pyramid → CPU Registers, Second layer from tip of Pyramid → L1, L2, L3, Cache (SRAM), Second layer from base of Pyramid → RAM (DRAM), Bottom of Pyramid → Secondary Storage
A Graphical User Interface (GUI) is the most common interface. Select one: True False
True
A file owner can grant or remove the access to a given file. Select one: True False
True
A nonpreemptive kernel is safe from race conditions on kernel data structures. Select one: True False
True
A thread will immediately acquire a dispatcher lock that is the signaled state. Select one: True False
True
A traditional (or heavyweight) process has a single thread of control. Select one: True False
True
Although caching and buffering are distinct functions, sometimes a region of memory can be used for both purposes. Select one: True False
True
At the boot time the system cannot interpret the file system format. Select one: True False
True
Both the test_ and_set() instruction and compare_and_swap() instruction are executed atomically. Select one: True False
True
Busy waiting refers to the phenomenon that while a process is in its critical section, any other process that tries to enter its critical section must loop continuously in the call to acquire the mutex lock. Select one: True False
True
CSTREAMS is the preferred method for writing protocols and device drivers in UNIX variants. Select one: True False
True
Cloud storage is accessed using a well-defined API. Select one: True False
True
Deadlock occurs when every thread in a set is blocked waiting for an event that can be caused only by another thread in the set, while livelock occurs when a thread continuously attempts an action that fails. Select one: True False
True
Each thread has its own register set and stack. Select one: True False
True
Files are stored in random-access storage devices. Select one: True False
True
In UNIX, a system configuration file, known as fstab (file systems table), includes information about files being mounted automatically at boot time. Select one: True False
True
In most RAID implementations, a hot spare disk is not used for data, but is configured for replacement should any other disk fail. Select one: True False
True
In preemptive scheduling, the sections of code affected by interrupts must be guarded from simultaneous use. Select one: True False
True
Indexed sequential-access method allows to locate any record with no more than two direct-access reads: Select one: True False
True
Instructions from different processes can be interleaved when interrupts are allowed. Select one: True False
True
It is possible to create a thread library without any kernel-level support. Select one: True False
True
It is possible to have a solution such that a given file system is mounted repeatedly at different mount points. Select one: True False
True
It is possible to have concurrency without parallelism. Select one: True False
True
KDE and GNOME desktops are available under open-source licenses. Select one: True False
True
Memory compression is commonly used in mobile systems instead of swapping. True False
True
Mutex locks and binary semaphores are essentially the same thing. Select one: True False
True
NFS "bridges" the Virtual File System of the client and the server across the network. Select one: True False
True
Part of the file system implementation has to include programmer API's such as read and write: Select one: True False
True
Program loading and execution is a system service. Select one: True False
True
Race conditions are prevented by requiring that critical regions be protected by locks. Select one: True False
True
STREAMS I/O is asynchronous except when the user process communicates with the stream head. Select one: True False
True
Simple operation of listing the contents of a specific directory, when unprotected, may be a threat to the system security: Select one: True False
True
The directory structure is creation of the file system design and not prescribed. Select one: True False
True
The local or remote file systems are the part of the third layer of virtual file system which is responsible for implementing file-system type or remote file system protocol. Select one: True False
True
The local variables of a monitor can be accessed by only the local procedures. Select one: True False
True
The x86-64 bit architecture only uses 48 of the 64 possible bits for representing virtual address space. True False
True
To recover remote file server from failure a file server should know what files have been open by clients. Select one: True False
True
Logical-file system is responsible for both managing metadata information and protection: Select one: True False
True It is the Logical File System that brings the concepts of names, meta data, and permissions and protection to the file system.
In Solaris, what is the time quantum (in milliseconds) of an interactive thread with priority 35? Select one: a. 80 b. 35 c. 25 d. 54
a. 80
In asynchronous replication, each block is written locally and remotely before the write is considered complete. Select one: a. False b. True
a. False
In tree-structured directory the search path always contains "the current directory" Select one: a. False b. True
a. False
If a current directory is /home/user/jane and then the propose path to file /home/user/mike/prog.c is_____________________ Select one: a. ../mike/prog.c b. ../../mike/prog.c c. /mike/prog.c d. ./mike/prog.c
a. ../mike/prog.c
If memory access time is 250 nanoseconds and the average page fault service time is 10 milliseconds, the probability of page faults must be less than _________________ to keep the performance degradation less than 20%. Select one: a. 0.000005 b. 0.000001 c. 0.0000075 d. 0.0000025 e. 0.00001
a. 0.000005
Given the logical address 0xAEF9 (in hexadecimal) with a page size of 256 bytes, what is the page number? Select one: a. 0xAE b. 0xF9 c. 0xA d. 0x00F9
a. 0xAE
Consider a 32-bit address for a two level paging system with an 8KB page size. The outer table has 1024 entries. How many bits are used to represent the second-level page table? Select one: a. 9 b. 10 c. 8 d. 12
a. 9
Child processes inherit UNIX ordinary pipes from their parent process because: Select one: a. A pipe is treated as a file descriptor and child processes inherit open file descriptors from their parents. b. The STARTUPINFO structure establishes this sharing. c. The pipe is part of the code and children inherit code from their parents. d. All IPC facilities are shared between the parent and child processes.
a. A pipe is treated as a file descriptor and child processes inherit open file descriptors from their parents.
Which of the following can be a solution to the problem of indefinite blockage of low-priority processes? Select one: a. Aging b. Multilevel queue c. All of the other answers d. Starvation
a. Aging
The following information is presented for the prog.c [-rwxr-xr-- 1 Jim staff 130 May 25 22:13 prog.c] Users Jim, Sara and Mike are the members of the group staff Select one: a. Alan can read prog.c b. Mike can read and write to prog.c c. Jim can invoke read and execute operation on prog.c d. Sara can modify prog.c
a. Alan can read prog.c
An advantage of virtual memory is that Select one: a. All of the above. b. it provides a way to execute a program that is only partially loaded in memory. c. a program can be much larger than the size of physical memory. d. the programmers can concentrate programming the problem instead of worrying about the amount of physical memory available.
a. All of the above.
In which of the following cases, performance may be improved? Select one: a. All of the above. b. Placing frequently interacting components close to one another. c. Designing array access pattern based on whether the arrays are stored in row major or column major order. d. Avoid placing functions across page boundaries.
a. All of the above.
The working set strategy Select one: a. All of the above. b. keeps the degree of multiprogramming as high as possible while preventing thrashing. c. swaps in a new process if there is enough memory available to accommodate its working set. d. swaps out a process if OS cannot allocate enough pages to accommodate its working set.
a. All of the above.
Buffering in I/O is used to Select one: a. All of the other options. b. support copy semantics for application I/O. c. cope with a speed mismatch between the producer and consumer of a data stream. d. provide adaptations for devices that have different data-transfer sizes.
a. All of the other options.
An interrupt priority scheme can be used to ____. Select one: a. All the other answers b.allow the most urgent work to be finished first c.defer the handling of low-priority interrupt without masking off all interrupts d.make it possible for high-priority interrupts to preempt the execution of a low priority interrupt
a. All the other answers
Which of the following selects from among the processes that are in the ready queue to execute and allocate the CPU to one of them? Select one: a. CPU scheduler b. swapping c. job scheduler d. context switch
a. CPU scheduler
Which of the following is true of the rate-monotonic scheduling algorithm? Select one: a. CPU utilization is bounded when using this algorithm. b. The task with the shortest period will have the lowest priority. c. Fine-It uses a dynamic priority policy. d. It is non-preemptive.
a. CPU utilization is bounded when using this algorithm.
_____ is/are not a technique for passing parameters from an application to a system call. Select one: a. Cache memory b. Stack c. Registers d. Special block in memory
a. Cache memory
Check all the answers that are benefits of a relocatable executable file format. Select one or more: a. Can be loaded anywhere in memory and not at a fixed address everytime b. Are great for the bootstrap code c. Allows for the same executable to be used on different operating systems. d. Can utilize dynamically linked libraries
a. Can be loaded anywhere in memory and not at a fixed address everytime d. Can utilize dynamically linked libraries
Which of the following is true of multilevel queue scheduling? Select one: a. Each queue has its own scheduling algorithm. b. Processes can move between queues. c. It is the most general CPU-scheduling algorithm. d. A queue cannot have absolute priority over lower-priority queues.
a. Each queue has its own scheduling algorithm.
_____ is the method of binding instructions and data to memory performed by most general-purpose operating systems. Select one: a. Execution time binding b. Load-time binding c. Interrupt binding d. Compile time binding
a. Execution time binding
A 32-bit logical address with 8 KB page size will have 1,000,000 entries in a conventional page table. Select one: a. False b. True
a. False
A reaper starts reclaiming pages as soon as the number of free frames falls below the maximum threshold. Select one: a. False b. True
a. False
A relocation register is used to check for invalid memory addresses generated by a CPU. Select one: a. False b. True
a. False
A track is the smallest unit of data transfer in a hard disk drive. Select one: a. False b. True
a. False
An expansion bus is used to connect relatively high speed devices to the main bus. Select one: a. False b. True
a. False
Applications compiled on one operating system can be directly executable on other operating systems due to common structure. Select one: a. False b. True
a. False
For counting method (used by free space management), the entries in the free-space list can be stored in a linked list, rather than a balanced tree, for efficient lookup, insertion, and deletion. Select one: a. False b. True
a. False
Fragmentation does not occur in a paging system. Select one: a. False b. True
a. False
In Java, data shared between threads is simply declared globally. Select one: a. False b. True
a. False
In UNIX, part of a path name includes a device name. Select one: a. False b. True
a. False
Interrupt chaining Select one: a. is a compromise between the overhead of a huge interrupt table and the inefficiency of dispatching to a single interrupt handler. b. allows CPU to defer processing of low-priority interrupts without masking all interrupts. c. is used to handle interrupts but not exceptions. d. splits interrupt management between first level and second level interrupt handlers.
a. is a compromise between the overhead of a huge interrupt table and the inefficiency of dispatching to a single interrupt handler.
A counting semaphore ____. Select one: a. is essentially an integer variable b. cannot be used to control access to a thread's critical sections c. is accessed through only one standard operation d. can be modified simultaneously by multiple threads
a. is essentially an integer variable
NFS (Network File System): Select one: a. is not fully consistent with UNIX Semantics. b. is consistent with Session Semantics. c. is consistent with Immutable-Shared-Files Semantics. d. is consistent with UNIX Semantics.
a. is not fully consistent with UNIX Semantics.
A RAID structure ____. Select one: a. is primarily used to ensure higher data reliability b. is primarily used to decrease the dependence on disk drives c. is primarily used for security reasons d. stands for redundant arrays of inexpensive disks
a. is primarily used to ensure higher data reliability
The file owner: Select one: a. is the user who can change the file attributes and grant access to the file. b. is the only user who can execute the file. c. is the user who cannot change the file attributes, but can execute the file. d. is the user who can change the file attributes, but cannot grant access to the file.
a. is the user who can change the file attributes and grant access to the file.
Which of the following data structure is used to manage the processes in Linux? Select one: a. linked list b. stack c. hash map d. tree
a. linked list
The ____ multithreading model multiplexes many user-level threads to a smaller or equal number of kernel threads. Select one: a. many-to-many model b. many-to-one model c. many-to-some model d. one-to-one model
a. many-to-many model
Which of the following information is shared when the flag CLONE_VM is set up? Select one: a. memory space b. file-system information c. set of open files d. signal handlers
a. memory space
A ___ type presents a set of programmer-defined operations that are provided mutual exclusion within it. Select one: a. monitor b. binary c. transaction d. signal
a. monitor
If a few bits in an HDD sector or NVM page are corrupted, the controller can recover the correct values using ECC only if Select one: a. number of bits corrupted is low irrespective of where the corruption occurs in the sector/page. b. the bit corruption is limited to the data portion of the sector/page. c. the bit corruption hasn't occurred in the ECC or the header of the sector/page. d. the bit corruption hasn't occurred in the ECC of the sector/page.
a. number of bits corrupted is low irrespective of where the corruption occurs in the sector/page.
Which classifications of users are typically used in access-control list to condense its length: Select one: a. owner, group, universe b. should not be directly modified by user c. owner, guest, universe d. owner, group
a. owner, group, universe
In polling I/O, the main inefficiency comes from Select one: a. polling when it is attempted repeatedly yet rarely finds a device ready for service. b. the hardware controller when it notifies the CPU that the device is ready for service. c. the slow data transfer rate between a device and the host. d. the basic polling operation that may be comprised of several CPU instructions.
a. polling when it is attempted repeatedly yet rarely finds a device ready for service.
What did the professor say is the best debugging tool that we need? Select one: a. printf b. gdb c. tcpdump d. your friend e. core dump f. google g. Geeks Programming
a. printf
Component that measures elapsed time and to trigger operations is called a Select one: a. programmable interval timer. b. socket. c. high performance event timer. d. network time protocol.
a. programmable interval timer.
The virtual file system layer: Select one: a. provides mechanisms for uniquely representing files b. maintains open file table c. allows access to the selected type of file d. provides mechanisms for uniquely representing filesis responsible for read(), write() calls
a. provides mechanisms for uniquely representing files
The device controller _____ an interrupt by asserting a signal on the interrupt request line. Select one: a. raises b. catches c. clears d. dispatches
a. raises
Which of the following process state will be switched from "running" state when an interrupt occurs? Select one: a. ready b. waiting c. terminated d. new
a. ready
Assume process P0 and P1 are the process before and after a context switch, and PCB0 and PCB1 are respectively their process control block. Which of the following time units are included inside the dispatch latency? Select one: a. save state into PCB0, and restore state from PCB1 b. P0 executing c. all of the other answers d. P1 executing
a. save state into PCB0, and restore state from PCB1
Replacement question: With segmentation in IA-32 architecture, a logical address consists of _____. Select one: a. segment number, GDT or LDT indicator, protection and offset b. segment number, page number, GDT/LDT, protection and offset c. segment number, page number and offset d. segment number and offset
a. segment number, GDT or LDT indicator, protection and offset
Which of the following is an inter-process communication that requires two processes share memory? Select one: a. shared memory b. all of the other answers c. message passing d. socket communication
a. shared memory
The absolute disk address: Select one: a. should not be directly modified by user b. helps solving the allocation problem c. is used in a direct communication with the user d. allows operating system to decide where to place a file
a. should not be directly modified by user
A call to pthread_cond_signal() Select one: a. signals one thread waiting on the condition variable, but does not release the mutex lock. b. signals all threads waiting on the condition variable, but does not release the mutex lock. c. releases the mutex lock and signals all threads waiting on the condition variable. d. releases the mutex lock and signals one thread waiting on the condition variable.
a. signals one thread waiting on the condition variable, but does not release the mutex lock.
Manipulating files through memory rather than using the read() and write() system calls_________________ Select one: a. simplifies and speeds up file access and usage b. is not recommended for single-processor operating systems c. complicates, but retards file access and usage d. simplifies, but retards file access and usage
a. simplifies and speeds up file access and usage
The ____ of a process contains temporary data such as function parameters, return addresses, and local variables. Select one: a. stack b. text section c. program counter d. data section
a. stack
A microkernel is a kernel ____. Select one: a. that is stripped of all nonessential components b. containing many components that are optimized to reduce resident memory size c. that is compiled to produce the smallest size possible when stored to disk d. that is compressed before loading in order to reduce its resident memory size
a. that is stripped of all nonessential components
Because all file systems suffer from internal fragmentation, the following relation is true: Select one: a. the larger block size, the greater the internal fragmentation b. the smaller block size, the greater the internal fragmentation c. the larger block size, the smaller internal fragmentation d. there is no relation between block size and internal fragmentation
a. the larger block size, the greater the internal fragmentation
For interactive systems, it is more important to minimize ________. Select one: a. the variance in response time b. the average response time c. the average turnaround time d. the waiting time
a. the variance in response time
To associate each thread created using an implicit technique such as a thread pool, with its unique transaction identifier, we could use ____? Select one: a. thread-local storage b. static data c. local variable d. global variable
a. thread-local storage
The most preferred method of swapping a process is Select one: a. to demand-page from the file system initially but to write the pages to swap space as they are replaced. b. None of the above. c. to swap using the file system. d. to copy an entire file to swap space at process startup and then perform demand paging from the swap space.
a. to demand-page from the file system initially but to write the pages to swap space as they are replaced.
A Flash Translation Layer Select one: a. tracks which physical block contains only invalid pages. b. tracks which physical block contains the most number of consecutive invalid pages. c. tracks which physical block contains only valid pages. d. translates user data to a format that can be written on the NVM.
a. tracks which physical block contains only invalid pages.
To the SYSGEN program of an operating system, the least useful piece of information is _____. Select one: a. what applications to install b. the CPU being used c. amount of memory available d. operating-system options such as buffer sizes or CPU scheduling algorithms
a. what applications to install
External fragmentation is Select one: a. when there is enough total memory space to satisfy a request but the available spaces are not contiguous. b. when the amount of available memory is less than the size of a process. c. when there is some unused memory that cannot be allocated to a process. d. when a process is broken up into smaller parts for memory allocation.
a. when there is enough total memory space to satisfy a request but the available spaces are not contiguous.
In the enhanced second chance algorithm, which of the following ordered pairs represents a page that would be the best choice for replacement? Select one: a. (1,0) b. (0,0) c. (1,1) d. (0,1)
b. (0,0)
A two-level directory can be thought as a tree of height _________ Select one: a. 1 and its root is MFD b. 2 and its root is MFD c. 2 and its root is UFD d. 1 and its root is UFD
b. 2 and its root is MFD
Suppose a program is operating with execution-time binding and the physical address generated is 300. The relocation register is set to 100. What is the corresponding logical address? Select one: a. 201 b. 200 c. 300 d. 199
b. 200
Consider a logical address with 18 bits used to represent an entry in a conventional page table. How many entries are in the conventional page table? Select one: a. 1,024 b. 262,144 c. 18 d. 1,048,576
b. 262,144
What is the size of the bit vector of a 1TB disk with 512-byte blocks? Select one: a. 8 MB b. 268 MB c. 2 MB d. 28 MB
b. 268 MB
The x86-64 architecture provides support for Select one: a. 64-bit physical addresses b. 52-bit physical addresses c. 32-bit physical addresses d. 48-bit physical addresses
b. 52-bit physical addresses
What size segment will be allocated for a 39KB request on a system using the Buddy system for kernel memory allocation? Select one: a. 39 KB b. 64 KB c. 42 KB d. None of the other answers
b. 64 KB
Suppose we have the following page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 4 and that there are three frames within our system. Using the FIFO replacement algorithm, what is the number of page faults for the given reference string? Select one: a. 13 b. 8 c. 10 d. 14
b. 8
When a child process is created, which of the following is a possibility in terms of the execution or address space of the child process? Select one: a. The child is a duplicate of the parent. b. All of the other answers c. The child process runs concurrently with the parent. d. The child process has a new program loaded into it.
b. All of the other answers
Which of the following principles is used to improve the efficiency of I/O? Select one: a. Move processing primitives into hardware, to allow their operation in device controllers to be concurrent with CPU and bus operation. b. All of the other options. c. Reduce the number of times that data must be copied in memory while passing between device and application. d. Increase concurrency by using DMA-knowledgeable controllers or channels to offload simple data copying from the CPU.
b. All of the other options.
A process may transition to the Ready state by which of the following actions? Select one: a. Newly-admitted process b. All the other answers c. Awaiting its turn on the CPU d. Completion of an I/O event
b. All the other answers
Which of the following statements is false with regard to allocating kernel memory? Select one: a. The slab allocator allows memory requests to be satisfied very quickly. b. Because the kernel requests memory of varying sizes, some of which may be quite small, the system does not have to be concerned about wasting memory. c. Slab allocation does not suffer from external fragmentation. d. Adjacent segments can be combined into one larger segment with the buddy system
b. Because the kernel requests memory of varying sizes, some of which may be quite small, the system does not have to be concerned about wasting memory.
Check all those that are true about the minimum number of frames. Select one or more: a. Certain instructions may span more than one page, therefore you must have at least two pages b. Certain instructions may span more than one page, therefore you have to the at least as many pages are required for that instruction to execute successfully. c. Only one frame is needed by any one process. d. The minimum number of frames is determined by the computers architecture.
b. Certain instructions may span more than one page, therefore you have to the at least as many pages are required for that instruction to execute successfully. d. The minimum number of frames is determined by the computers architecture.
Which of the following technique is well suited to support very large address space, e.g. 64-bit address space? Select one: a. Hierarchical page tables b. Clustered page tables c. All of the above d. Inverted page tables
b. Clustered page tables
12.UNIX rm command can delete non-empty directory Select one: a. True b. False
b. False
A maskable interrupt can never be disabled. Select one: a. True b. False
b. False
A monitor is an abstract data type that is based on semaphore implementation. Select one: a. True b. False
b. False
A system call is triggered by hardware. Select one: a. True b. False
b. False
All access to POSIX shared memory requires a system call. Select one: a. True b. False
b. False
CAS-based synchronization is always faster than traditional synchronization. Select one: a. True b. False
b. False
Data striping provides reliability for RAID systems. Select one: a. True b. False
b. False
Disk controllers do not usually have a built-in cache. Select one: a. True b. False
b. False
Grand Central Dispatch requires multiple threads. Select one: a. True b. False
b. False
Hierarchical page tables are appropriate for 64-bit architectures. Select one: a. True b. False
b. False
In Linux, a slab may only be either full or empty. Select one: a. True b. False
b. False
In RR scheduling, the time quantum should be small with respect to the context-switch time. Select one: a. True b. False
b. False
Inverted page tables require each process to have its own page table. Select one: a. True b. False
b. False
Is the set of the file's attributes the same for each operating system? Select one: a. True b. False
b. False
Mobile operating systems typically support swapping. Select one: a. True b. False
b. False
Peterson's solution works on modern computer architectures. Select one: a. True b. False
b. False
Reentrant code cannot be shared. Select one: a. True b. False
b. False
SCAN disk head scheduling offers no practical benefit over FCFS disk head scheduling. Select one: a. True b. False
b. False
Which of the following statements are false with regards to the Linux CFS scheduler? Select one: a. Lower numeric values indicate higher relative priorities. b. There is a single, system-wide value of vruntime. c. The scheduler doesn't directly assign priorities. d. Each task is assigned a proportion of CPU processing time.
b. There is a single, system-wide value of vruntime.
Which of the following statements regarding solid state disks (SSDs) is false? Select one: a. They are generally more expensive per megabyte than traditional hard disks. b. They generally consume more power than traditional hard disks. c. They have no seek time or latency. d. They have the same characteristics as magnetic hard disks, but can be more reliable.
b. They generally consume more power than traditional hard disks.
__________ occurs when a process spends more time paging than executing. Select one: a. Swapping b. Thrashing c. Memory-mapping d. Demand paging e. Trashing
b. Thrashing
A Solaris interactive thread with a time quantum of 80 has a higher priority than an interactive thread with a time quantum of 120. Select one: a. False b. True
b. True
A page fault must be preceded by a TLB miss. Select one: a. False b. True
b. True
Amdahl's Law describes performance gains for applications with both a serial and parallel component. Select one: a. False b. True
b. True
Application programmers typically use an API (library functions) rather than directory invoking system calls. Select one: a. False b. True
b. True
Deferred cancellation is preferred over asynchronous cancellation. Select one: a. False b. True
b. True
Each system should have at least one file system which is bootable. Select one: a. False b. True
b. True
For a single-processor system, there will never be more than one process in the Running state. Select one: a. False b. True
b. True
Hashed page tables are particularly useful for processes with sparse address spaces. Select one: a. False b. True
b. True
In file systems consistent with Session Semantics, the changes in a file are made visible to new sessions only, but are not seen by current sessions. Select one: a. False b. True
b. True
In general, Windows system calls have longer, more descriptive names and UNIX system calls use shorter, less descriptive names. Select one: a. False b. True
b. True
In hard real-time systems, interrupt latency must be bounded. Select one: a. False b. True
b. True
In swapping with paging technique, individual pages of a process are swapped in or out. Select one: a. False b. True
b. True
In the Linux CFS scheduler, the task with smallest value of vruntime is considered to have the highest priority. Select one: a. False b. True
b. True
One-to-one model provides more concurrency than the many-to-one model by allowing another thread to run when a thread makes a blocking system call. Select one: a. False b. True
b. True
Ordinary pipes are unidirectional, allowing only one-way communication. Select one: a. False b. True
b. True
Ordinary pipes in UNIX require a parent-child relationship between the communicating processes. Select one: a. False b. True
b. True
Processors for most mobile devices run at a slower speed than a processor in a desktop PC. Select one: a. False b. True
b. True
RAID level 0 provides no redundancy. Select one: a. False b. True
b. True
Solutions to the critical section problem may suffer from liveness failures. Select one: a. False b. True
b. True
Some operating systems provide raw disk, so that special applications can bypass file system when accessing secondary storage. Select one: a. False b. True
b. True
The Completely Fair Scheduler (CFS) is the default scheduler for Linux systems. Select one: a. False b. True
b. True
The current best practice to avoid thrashing is to include enough physical memory. Select one: a. False b. True
b. True
Without a mechanism such as an address-space identifier, the TLB must be flushed during a context switch. Select one: a. False b. True
b. True
iOS and Android combine different structures, resulting in hybrid systems that address performance, security, and usability issues. Select one: a. False b. True
b. True
init is the very first process for a typical Linux system. Select one: a. False b. True
b. True
MapReduce is a system which allows for parallel processing of data across nodes in the cluster. Select one: a. No b. Yes
b. Yes
Skype uses a hybrid peer-to-peer approach. Select one: a. No b. Yes
b. Yes
Write amplification involves Select one: a. finding a block that has not yet been written. b. a page write, one or more page reads, and one or more page writes. c. writing a large number of redundant bytes to improve reliability. d. writing all blocks of the device.
b. a page write, one or more page reads, and one or more page writes.
A page fault occurs when __________________________ Select one: a. a page table is not large enough to include all page table entries. b. a process tries to access a page that is not loaded in memory. c. the size of a process is larger than the size of physical memory. d. a page in memory gets corrupted.
b. a process tries to access a page that is not loaded in memory.
Replacement Question: Address translation from a logical address to a physical address in IA-32 architecture is comprised of Select one: a. a paging unit followed by a segmentation unit that translates the logical address to its physical address. b. a segmentation unit followed by a paging unit that translate the logical address to its physical address. c. a segmentation unit that translates the logical address to its physical address. d. a paging unit that translates the logical address to its physical address.
b. a segmentation unit followed by a paging unit that translate the logical address to its physical address.
Pthreads refers to ____. Select one: a. the POSIX standard. b. a specification for thread behavior. c. an API for process creation and synchronization. d. an implementation for thread behavior.
b. a specification for thread behavior.
A directory entry MUST have: Select one: a. the name of the file b. a way to find the data associated with a file c. all the meta data for a file d. a file control block
b. a way to find the data associated with a file
Sequential access can be optimized by Select one: a. none of the other answers b. all of the other answers c. read-ahead technology d. free-behind technology
b. all of the other answers
The ready queue can be implemented as a _______________. Select one: a. unordered linked list b. all of the other answers c. priority queue d. tree e. FIFO queue
b. all of the other answers
Which of the following cancellation modes are supported by Pthreads? Select one: a. deferred mode b. all of the other answers c. off mode d. asynchronous mode
b. all of the other answers
Which of the following may cause a liveness failure? Select one: a. a busy waiting loop b. all of the other answers c. an infinite loop d. a deadlock
b. all of the other answers
A solution to the critical section problem does not have to satisfy which of the following requirements? Select one: a. progress b. atomicity c. mutual exclusion d. bounded waiting
b. atomicity
Compared to USB, NVMe provides Select one: a. neither higher throughput and lower latency. b. both higher throughput and lower latency. c. lower latency, but lower throughput. d. higher throughput, but higher latency.
b. both higher throughput and lower latency.
A translation look-aside buffer is used to Select one: a. store the address of the page table in memory. b. cache page table entries. c. store page size. d. size of the logical address space of the currently running process.
b. cache page table entries.
A(n) _______ refers to where a process is accessing/updating shared data. Select one: a. mutex b. critical section c. entry section d. test-and-set
b. critical section
Which of the following contains global data? Select one: a. stack section b. data section c. text section d. heap section
b. data section
Which of the following options to deliver signals in multithreaded program should be applied to a synchronous signal? Select one: a. deliver the signal to every thread in the process b. deliver the signal to the thread to which the signal applies c. assign a specific thread to receive all signals for the process d. deliver the signal to certain threads in the process e. all of the other answers
b. deliver the signal to the thread to which the signal applies
Which access type should be used when there is a need for a fast access to massive amount of data: Select one: a. sequential access b. direct access c. index-sequential access d. index access
b. direct access
The NFS protocol: Select one: a. does not provide concurrency control mechanisms except file locking. b. does not provide concurrency control mechanisms. c. provides concurrency control mechanisms. d. may provide concurrency control mechanisms.
b. does not provide concurrency control mechanisms.
Memory compression is a useful alternative to paging Select one: a. when the system has slow magnetic disks but not faster SSDs. b. even when the system has faster SSDs. c. when the compression algorithm is can achieve the best possible compression ratio. d. when the speed of the compression algorithm fastest.
b. even when the system has faster SSDs.
Which of the following system calls is used to have a new program loaded into the new process's memory space? Select one: a. fork() b. exec() c. wait() d. exit()
b. exec()
An instruction that executes atomically ____. Select one: a. cannot be used to solve the critical section problem b. executes as a single, uninterruptible unit c. must consist of only one machine instruction d. All of the other answers
b. executes as a single, uninterruptible unit
Memory-mapped I/O works well with devices that are characterized by: Select one: a. requiring large buffers b. fast response times c. requiring small buffers d. slow response times
b. fast response times
A file may be associated with several images at the same time in: Select one: a. file systems consistent with UNIX Semantics. b. file systems consistent with Session Semantics. c. file systems consistent with NFS (Network File System) Semantics. d. file systems consistent with Windows Semantics.
b. file systems consistent with Session Semantics.
Which of the following principles is used for adding and removing items from a queue? Select one: a. random order b. first in first out (FIFO) c. round robin d. last in first out (LIFO)
b. first in first out (FIFO)
Belady's anomaly states that ________________________. Select one: a. as the number of allocated frames increases, the page-fault rate may decrease for all page replacement algorithms b. for some page replacement algorithms, the page-fault rate may increase as the number of allocated frames increases c. for some page replacement algorithms, the page-fault rate may decrease as the number of allocated frames increases d. giving more memory to a process will improve its performance
b. for some page replacement algorithms, the page-fault rate may increase as the number of allocated frames increases
Copy on write is typically associated with which which system call? Select one: a. execvp b. fork c. malloc d. exec e. knife
b. fork
Under which of the following contention loads does traditional synchronization become faster than CAS-based synchronization? Select one: a. none of the other answers b. high contention c. uncontended d. moderate contention
b. high contention
One necessary condition for deadlock is ____, which states that a process must be holding one resource and waiting to acquire additional resources. Select one: a. no preemption b. hold and wait c. circular wait d. mutual exclusion
b. hold and wait
File's _______ is a unique tag identifies the file within the file system. Select one: a. name b. identifier c. type d. location
b. identifier
Another problem related to deadlocks is ____________. Select one: a. critical sections b. indefinite blocking c. race conditions d. spinlocks
b. indefinite blocking
Which of the following clears the interrupt by servicing the device? Select one: a. interrupt-controller hardware b. interrupt service routine c. interrupt vector d. interrupt request line
b. interrupt service routine
A linked free list uses no extra hard drive space, but has what drawback: Select one: a. you get a lot of internal fragmentation b. is harder to find contiguous free blocks c. that it takes more main memory d. that it is hard to code
b. is harder to find contiguous free blocks
Thread-local storage is data that ____. Select one: a. has been modified by the thread, but not yet updated to the parent process b. is unique to each thread c. is generated by the thread independent of the thread's process d. is not associated with any process
b. is unique to each thread
Which of the following principles is used for adding and removing items from a stack? Select one: a. random order b. last in first out (LIFO) c. round robin d. first in first out (FIFO)
b. last in first out (LIFO)
Which of the following is tertiary storage medium? Select one: a. hard-disk drive b. magnetic tapes c. register d. main memory
b. magnetic tapes
With _______ locking, once a process acquires an exclusive lock, the operating system will prevent any other process from accessing the locked file. Select one: a. temporary b. mandatory c. exclusive d. shared
b. mandatory
The mapping of a logical address to a physical address is done in hardware by the _____________. Select one: a. relocation register b. memory-management-unit (MMU) c. memory address register d. dynamic loading register
b. memory-management-unit (MMU)
To further optimize I/O performance, some SSD schedulers Select one: a. merge adjacent read requests but not adjacent write requests. b. merge adjacent write requests but not adjacent read requests. c. merge all adjacent I/O requests. d. do not merge requests at all.
b. merge adjacent write requests but not adjacent read requests.
Disk scheduling algorithms in operating systems consider only seek distances, because Select one: a. it is difficult to optimize seek time in disk hardware. b. modern disks do not disclose the physical location of logical blocks. c. the operating systems may have other constraints such as writes may be more urgent than reads. d. rotational latency is insignificant compared to the average seek time.
b. modern disks do not disclose the physical location of logical blocks.
Systems in which memory access times vary significantly are known as ______________. Select one: a. memory-mapped I/O b. non-uniform memory access c. demand-paged memory d. copy-on-write memory
b. non-uniform memory access
Which of the following is allowed on Linux and Mac OS X systems? Select one: a. Both PTHREAD_SCOPE_PROCESS and PTHREAD_SCOPE_SYSTEM b. only PTHREAD_SCOPE_SYSTEM c. only PTHREAD_SCOPE_PROCESS d. none of the other answers
b. only PTHREAD_SCOPE_SYSTEM
When the exclusive lock is applied to a file then _____________ Select one: a. only one process can write to this file, but many processes can read it concurrently b. only one process can use this file c. processes can write to this file only d. many processes can read and write to this file concurrently
b. only one process can use this file
What is the relationship between library call open() and open() system call? Select one: a. open() is a predecessor version of open() system call b. open() invokes open() system call to get service from operating system c. open() system call is part of open() d. open() system call in an alternate version of open()
b. open() invokes open() system call to get service from operating system
Unified virtual memory uses _____________ to cache both process page and file data Select one: a. double caching b. page caching c. disk block caching d. buffer caching
b. page caching
DRAMs are now commonly used for mass data storage, because Select one: a. DRAMs are cheaper than SSDs. b. programs can share data easily when using RAMs. c. storage capacity of DRAMS is typically much larger than HDDs. d. programs may not need the data they store in future.
b. programs can share data easily when using RAMs.
Which of the following critical-section problem's requirements ensures programs will cooperatively determine what process will next enter its critical section? Select one: a. none of the other answers b. progress c. bounded waiting d. mutual exclusion
b. progress
The _____ allocation algorithm allocates available memory to each process according to its size. Select one: a. slab b. proportional c. equal d. global
b. proportional
Which of the following POSIX API sets the scheduling policy? Select one: a. pthread_attr_getscope b. pthread_attr_setsched_policy c. pthread_attr_getsched_policy d. pthread_attr_setscope
b. pthread_attr_setsched_policy
The first readers-writers problem ____. Select one: a. requires that no reader will be kept waiting unless a reader has already obtained permission to use the shared database. b. requires that no reader will be kept waiting unless a writer has already obtained permission to use the shared database. c. is not used to test synchronization primitives. d. requires that, once a writer is ready, that writer performs its write as soon as possible.
b. requires that no reader will be kept waiting unless a writer has already obtained permission to use the shared database.
Which is true about a linear list: Select one: a. can only be fixed size b. simpler to program c. faster to search d. harder to program than hash tables
b. simpler to program
Which of the following storage medium is the slowest regarding access speed? Select one: a. cache b. solid state drive c. register d. main memory
b. solid state drive
A(n) ____ is a buffer that holds output for a device that cannot accept interleaved data streams. Select one: a. cache b. spool c. escape d. block device
b. spool
Which of the following structures defines the process control block for Linux system? Select one: a. mm_struct b. task_struct c. files_struct d. schedu_entity
b. task_struct
A sign of thrashing is Select one: a. the CPU utilization increases as the degree of multiprogramming is increased. b. the CPU utilization decreases as the degree of multiprogramming is increased. c. the CPU utilization increases as the number of pages allocated to each process is increased. d. the CPU utilization decreases as the number of pages allocated to each process is increased.
b. the CPU utilization decreases as the degree of multiprogramming is increased.
Standard swapping is generally not used in contemporary operating systems, becuase Select one: a. contemporary operating systems fo not oversubscribe memory. b. the amount of time required to move entire processes between main memory and the backing store is prohibitive. c. memory in contemporary systems is large enough to store all processes. d. some processes are so large that they cannot fit in backing store.
b. the amount of time required to move entire processes between main memory and the backing store is prohibitive.
Reentrant code is easier to share when paging is used, because Select one: a. each process can modify that code its own way. b. the code doesn't change during execution. c. All of the above. d. the code changes are identical for each process.
b. the code doesn't change during execution.
Prepaging can be an advantage, becuase Select one: a. the initial pages a process accesses are typically wel known in advance. b. the cost of using prepaging is less than the cost of servicing the corresponding page faults. c. All of the other answers. d. prepaging starts before a process is scheduled for execution
b. the cost of using prepaging is less than the cost of servicing the corresponding page faults.
Mounting a file systems means that: Select one: a. the file system is removed from the disk space. b. the file system is becoming available within the file system name space. c. the file system is becoming unavailable within the file system name space. d. the file system is being created in the disk space.
b. the file system is becoming available within the file system name space.
For our purposes the MBR specifies _________. Select one: a. the complete structure of the disk b. the information needed to define that volume (as partitioned by the partition record) c. the partitions of the disk d. how to boot
b. the information needed to define that volume (as partitioned by the partition record)
A current trend in I/O device technology and I/O subsystem is Select one: a. to encapsulate the oddities of different I/O devices, the device drivers present device-specific interface for each device to the I/O subsystem. b. there is an increasingly broad variety of I/O devices. c. All of the other options. d. new devices are similar to the previous I/O devices that makes it easier to incorporate them in operating systems.
b. there is an increasingly broad variety of I/O devices.
Which of the following is a user interface where human fingers slide across the screen or press buttons to select choices? Select one: a. graphical user interface b. touch screen c. voice control d. command line
b. touch screen
The surface of a magnetic disk platter is divided into ____. Select one: a. arms b. tracks c. sectors d. cylinders
b. tracks
Escape (or back door) in application I/O interface Select one: a. allows a user to interrupt a device at any time. b. transparently passes arbitrary commands from an application to a device driver. c. allows access to a few additional devices, such as a time-of-day clock and a timer. d. enables managing of devices with widely varying speeds ranging from a few bytes per second to gigabytes per second.
b. transparently passes arbitrary commands from an application to a device driver.
The two separate modes of operating in a system are Select one: a. supervisor mode and system mode b. user mode and kernel mode c. physical mode and logical mode d. kernel mode and privileged mode
b. user mode and kernel mode
(Check all that apply) A volume control block is: Select one or more: a. contains information about how many files and directories there are b. usually stored at logical block 0 of the volume c. is only in memory d. contains basic information about the volume, including number of blocks, block size, and indices for the free space and root directory e. usually stored at the beginning of the physical hard drive
b. usually stored at logical block 0 of the volume d. contains basic information about the volume, including number of blocks, block size, and indices for the free space and root directory
Which of the following process state will be switched from "running" state when an I/O event occurs? Select one: a. terminated b. waiting c. ready d. new
b. waiting
Which of the following circumstances can cooperative scheduling take place? Select one: a. none of the other answers b. when a process switches from the running state to the waiting state c. when a process switches from the waiting state to the ready state d. when a process switches from the running state to the ready state
b. when a process switches from the running state to the waiting state
A process that has terminated, but whose parent has not yet called wait(), is known as a ________ process. Select one: a. init b. zombie c. terminated d. orphan
b. zombie
Which of the following is a principle that can improve the efficiency of I/O? Select one: a.Use small data transfers b.Move processing primitives into hardware c.Decrease concurrency using DMA controllers d.Increase the number of context switches.
b.Move processing primitives into hardware
In FAT used in MS-DOS, Select one: a. None of the other choices b.a string preceding the colon that identifies the storage device. c.the storage device is identified in the path name with no clear separation of the device portion. d.the mount table stores the identities of all storage devices.
b.a string preceding the colon that identifies the storage device.
DMA controllers ____. Select one: a.are a nonstandard component in PCs of today b.can steal memory access cycles from the main CPU c.do not utilize an additional, special purpose, processor d.can access main memory at the same time as the main CPU
b.can steal memory access cycles from the main CPU
What is the degree of multiprogramming for a single-processor system? Select one: a. 3 b. 2 c. 1 d. 0
c. 1
The rate of a periodic task in a hard real-time system is ____, where p is a period and t is the processing time. Select one: a. p/t b. 1/t c. 1/p d. pt
c. 1/p
Assume a system uses 2-level paging and has a TLB hit ratio of 90%. It requires 15 nanoseconds to access the TLB, and 85 nanoseconds to access main memory. What is the effective memory access time in nanoseconds for this system? Select one: a. 22 b. 108.5 c. 117 d. 30.5
c. 117
If the base register is loaded with value 12345 and limit register is loaded with value 1000, which of the following memory address access will not result in a trap to the operating system? Select one: a. 12200 b. 12344 c. 12500 d. 13346
c. 12500
A hard disk drive has 16 platters, 8192 cylinders, and 256 4KB sectors per track. The storage capacity of this disk drive is at most Select one: a. 32 TB. b. 128 TB. c. 128 GB. d. 32 GB.
c. 128 GB.
Consider a logical address with a page size of 8KB. How many bits must be used to represent the page offset (displacement) in the logical address? Select one: a. 22 b. 8 c. 13 d. 12 e. 10
c. 13
How many philosophers may eat simultaneously in the Dining Philosophers problem with 5 philosophers? Select one: a. 5 b. 4 c. 2 d. 1 e. 3
c. 2
Suppose we have the following page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 4 and that there are three frames within our system. Using the FIFO replacement algorithm, what will be the final configuration of the three frames following the execution of the given reference string? Select one: a. 3, 1, 4 b. 4, 1, 3 c. 3, 4, 2 d. 4, 2, 3
c. 3, 4, 2
Which of the following statements are true with respect to hashed page tables? Select one: a. Hash table collisions do not occur because of the importance of paging. b. They only work for sparse address spaces. c. A common approach for handling address spaces larger than 32 bit. d. The virtual address is used to hash into the hash table.
c. A common approach for handling address spaces larger than 32 bit.
Which of the following is true of cooperative scheduling? Select one: a. It requires a timer. b. It incurs a cost associated with access to shared data. c. A process keeps the CPU until it releases the CPU either by terminating or by switching to the waiting state. d. A process switches from the running state to the ready state when an interrupt occurs.
c. A process keeps the CPU until it releases the CPU either by terminating or by switching to the waiting state.
Which of the following is true about the strategy that uses page fault frequency (PFF) to prevent thrashing? Select one: a. A new page is allocated to a process if PFF is too high. b. A new process may be swapped in if PFF is too low. c. All of the above. d. A page is deallocated from a process if the PFF is too low.
c. All of the above.
Which of the following is a benefit of allowing a program that is only partially in memory to execute? Select one: a. Programs can be written to use more memory than is available in physical memory. b. Less I/O is needed to load or swap each user program into memory. c. All of the other answers. d. CPU Utilization and throughput is increased.
c. All of the other answers.
Read or write performance of a hard disk drive depends on Select one: a. rotational latency b. seek time c. All the other answers d. bit transfer rate
c. All the other answers
Which of the following is FALSE about Storage Area Networks? Select one: a. SANs make it possible for clusters of servers to share the same storage. b. Multiple hosts can attach to the same SAN. c. Allocation of storage to hosts is static. d. SANs use storage protocols rather than network protocols.
c. Allocation of storage to hosts is static.
What is the key advantage of swapping? Select one: a. That you can preserve a process on the hard disk. b. Provides a communication mechanism between a process and the operating system. c. Allows the allocation of more memory then the main memory on the system. d. Provides a communication mechanism between applications. e. Makes loading of applications faster.
c. Allows the allocation of more memory then the main memory on the system.
Which of the following is true? Select one: a. An I/O-bound process is one that spends more of its time doing computations than it spends doing I/O b. Both of the other 2 (other than none) c. An I/O-bound process is one that spends more of its time doing I/O than it spends doing computations d. none of the other answers
c. An I/O-bound process is one that spends more of its time doing I/O than it spends doing computations
I/O-bound program typically has many short ______ and a CPU-bound program might have a few long __________. Select one: a. I/O burst, I/O burst b. CPU burst, I/O burst c. CPU burst, CPU burst d. I/O burst, CPU burst
c. CPU burst, CPU burst
If the time quantum gets too large, RR scheduling degenerates to __________? Select one: a. Shortest-remaining-time-first b. Multilevel queue c. FCFS d. SJF
c. FCFS
Which of the following scheduling algorithm may suffer from convoy effect? Select one: a. SJF b. Multilevel queue c. FCFS d. RR
c. FCFS
Which of the following is the denotation of 1024^3 bytes? Select one: a. MB b. TB c. GB d. KB
c. GB
When an application over allocates memory the application can cause thrashing. Which application is an example of a program that causes thrashing? Select one: a. Microsoft Edge b. Apple Safari c. Google Chrome d. Firefox
c. Google Chrome
Consistency semantics determines: Select one: a. How the information about files that are currently open is stored b. How modifications of data change the internal structure of a file system c. How modifications of data are observable to other users d. How the virtual file system layer maintains the internal file representation structure
c. How modifications of data are observable to other users
Consistency semantics determines: Select one: a. How the information about files that are currently open is stored b. How the virtual file system layer maintains the internal file representation structure c. How modifications of data are observable to other users d. How modifications of data change the internal structure of a file system
c. How modifications of data are observable to other users
Which of the following is true about choosing an appropriate page size? Select one: a. Smaller page size reduces the number of page faults. b. Larger page size results in reducing total I/O. c. Larger page size reduces I/O time. d. Larger page size results in less total allocated memory.
c. Larger page size reduces I/O time.
FCFS scheduling is generally used in NVMs, because Select one: a. it provides much higher raw throughput compared to HDDs. b. write service time is not uniform in NVMs. c. NVMs do not contain moving disk heads. d. the write performance depends on how "worn" the media is.
c. NVMs do not contain moving disk heads.
Which of the following scheduling algorithms gives the minimum average response time? Select one: a. FCFS b. SJF c. RR d. Multilevel queue
c. RR
_____ is not one of the major categories of system calls. Select one: a. Protection b. Communications c. Security d. Process Control
c. Security
Which of the following statements is true? Select one: a. Message passing is typically faster than shared memory. b. Message passing is most useful for exchanging large amounts of data. c. Shared memory is typically faster than message passing. d. Shared memory is far more common in operating systems than message passing.
c. Shared memory is typically faster than message passing.
Which algorithm evaluation method yields the best results? Select one: a. Deterministic Evaluation b. Implement new scheduler and test in real systems c. Simulations d. Queueing Models
c. Simulations
_____ provide(s) an interface to the services provided by an operating system. Select one: a. Shared memory b. Communication c. System calls d. Simulators
c. System calls
Which of the following is the denotation of 1024^4 bytes? Select one: a. KB b. MB c. TB d. GB
c. TB
Which of the following is considered a benefit when using the slab allocator? Select one: a. It allows larger segments to be combined using coalescing. b. It allows kernel code and data to be efficiently paged. c. There is no external memory fragmentation. d. Memory is allocated using a simple power-of-2 allocator.
c. There is no external memory fragmentation.
Which of the following criteria is more important from the point of view of a particular process? Select one: a. Response time b. CPU utilization c. Turnaround time d. Throughput
c. Turnaround time
In Pthreads, a parent uses the pthread_join() function to wait for its child thread to complete. What is the equivalent function in Win32? Select one: a. wait() b. win32_join() c. WaitForSingleObject() d. join()
c. WaitForSingleObject()
The system-wide open-file table contains: Select one: a. only names of each open file b. a pointer to the file control block of each open file c. a copy of the file control block of each open file d. only names and addresses of each open file
c. a copy of the file control block of each open file
The _____________ refers to the number of processes in memory. Select one: a. long-term scheduler b. process count c. degree of multiprogramming d. CPU Scheduler
c. degree of multiprogramming
Which of the following processes usually have highest priority? Select one: a. system processes b. interactive processes c. real-time processes d. batch processes
c. real-time processes
A cycle in a resource-allocation graph is ____. Select one: a. a necessary and sufficient condition for deadlock in the case that each resource has more than one instance b. a sufficient condition for a deadlock in the case that each resource has more than once instance c. a necessary and sufficient condition for a deadlock in the case that each resource has exactly one instance d. is neither necessary nor sufficient for indicating deadlock in the case that each resource has exactly one instance
c. a necessary and sufficient condition for a deadlock in the case that each resource has exactly one instance
In demand paging, Select one: a. all pages that a program will access during execution are loaded in memory in the beginning. b. a page loaded in memory may never be accessed. c. a page is loaded in memory only when it is needed during execution. d. a page is loaded in memory just before it is needed.
c. a page is loaded in memory only when it is needed during execution.
Lock bit is NOT used for which of the following cases: Select one: a. some OS pages. b. the page that is being used for I/O. c. a page that belongs to a high priority process. d. a new page that has just been brought in.
c. a page that belongs to a high priority process.
In a dynamically linked library _________. Select one: a. loading is postponed until execution time b. system language libraries are treated like any other object module c. a stub is included in the image for each library-routine reference d. more disk space is used than in a statically linked library
c. a stub is included in the image for each library-routine reference
Host-attached storage is ____. Select one: a. not suitable for use in raid arrays b. a special purpose storage system that is accessed remotely over a data network c. accessed via local I/O ports d. not suitable for hard disks
c. accessed via local I/O ports
Computing systems need cache because Select one: a. All of the about. b. main memory is expensive and cache offsets the cost. c. accessing main memory is slow and cache speeds it up. d. register access is slow and cache speeds it up.
c. accessing main memory is slow and cache speeds it up.
The file protection can be provided by: Select one: a. access-control list b. password c. all of the other answers d. knowledge of the existence and name of a file
c. all of the other answers
The following characteristics of disks make them convenient for being the secondary storage: Select one: a. it is possible to read a block from the disk, modify the block, and write it back into the same place b. none of the other answers c. all of the other answers d. a disk can access directly any block of information it contains
c. all of the other answers
Which of the following are efforts to towards developing scalable, efficient tools that address the demands of concurrent programming? Select one: a. developing languages that provide support for concurrent programming b. designing compilers that generate more efficient code c. all of the other answers d. improving the performance of existing libraries and APIs
c. all of the other answers
_______________ is used to implement a file system. Select one: a. A volume control block b. A directory structure. c. all of the other answers d. A boot control block
c. all of the other answers
A page address extension (PAE) in IA-32 _______________________. Select one: a. increases address size to 64 bits. b. does not need any operating system support. c. allows 32-bit processors to access a physical address space larger than 4GB. d. introduces two-level paging scheme.
c. allows 32-bit processors to access a physical address space larger than 4GB.
In __________ write, the data are stored in the cache, and control returns to the caller. Select one: a. a synchronous b. a non-buffered c. an asynchronous d. a buffered
c. an asynchronous
UNIX inode is an example of _______ Select one: a. a contiguous allocation. b. an index file c. an indexed allocation d. a linked allocation
c. an indexed allocation
In Little's formula, λ, represents the ____. Select one: a. average queue length b. average waiting time in the queue c. average arrival rate for new processes in the queue d. average CPU utilization
c. average arrival rate for new processes in the queue
Which of the following is true regarding the requirements for the solutions to critical-section problem? Select one: a. none of the other answers b. progress implies bounded waiting c. bounded waiting implies progress d. mutual exclusion implies progress
c. bounded waiting implies progress
Absolute code can be generated for ____________. Select one: a. execution-time binding b. interrupt binding c. compile-time binding d. load-time binding
c. compile-time binding Binding means that the address is resolved and no longer needs attention beyond that point.
The root-partition: Select one: a. does not contain the operating system kernel, but it is the first mounted file system during the boot time. b. contains an operating system kernel and it is not necessary to be mounted. c. contains an operating system kernel and it is mounted during boot time. d. contains a list of the operating systems which may be booted.
c. contains an operating system kernel and it is mounted during boot time.
The ______ occurs in first-come-first-served scheduling when a process with a long CPU burst occupies the CPU. Select one: a. dispatch latency b. system-contention scope c. convoy effect d. waiting time
c. convoy effect
Which free space management approach takes advantage of the fact that multiple contiguous blocks may be allocated or freed simultaneously Select one: a. linked lists b. grouping c. counting d. space maps
c. counting
If a program terminates abnormally, a dump of memory may be examined by a ____ to determine the cause of the problem. Select one: a. control card b. shell c. debugger d. module
c. debugger
close() operation _____ an open count associated with a given file. Select one: a. increases b. does not change c. decreases d. resets
c. decreases
Which of the following cancellation modes is the default cancellation type? Select one: a. off mode b. all of the other answers c. deferred mode d. asynchronous mode
c. deferred mode
Which of the following options to deliver signals in multithreaded program should be applied to an asynchronous signal that terminates a process (<control><C>, for example)? Select one: a. deliver the signal to the thread to which the signal applies b. assign a specific thread to receive all signals for the process c. deliver the signal to every thread in the process d. all of the other answers e. deliver the signal to certain threads in the process
c. deliver the signal to every thread in the process
On media that uses constant linear velocity, the ____. Select one: a. disk's rotation speed increases as the head moves towards the middle of the disk from either side b. density of bits decreases from the inner tracks to the outer tracks c. density of bits per track is uniform d. disk's rotation speed remains constant
c. density of bits per track is uniform
Stack algorithms are a class of page replacement algorithms that Select one: a. are guaranteed to incur the least number of page faults. b. are implemented using stacks. c. do not suffer from Belady's anomaly. d. are guaranteed to incur no more page faults than FIFO page replacement algorithm.
c. do not suffer from Belady's anomaly.
The _____ binding scheme facilitates swapping. Select one: a. load time b. assembly time c. execution time d. interrupt time
c. execution time
The roll out, roll in variant of swapping is used ____. Select one: a. for the round-robin scheduling algorithm b. when the load on the system has temporarily been reduced c. for priority-based scheduling algorithms d. when a backing store is not necessary
c. for priority-based scheduling algorithms
Which of the following system calls is used to let the parent process create a child process? Select one: a. exec(). b. wait(); c. fork(); d. abort();
c. fork();
Which of the following is not an operating system service? Select one: a. I/O operation b. program execution c. graphical user interface d. protection and security
c. graphical user interface
______ is a mobile operating system designed for the iPhone and iPad. Select one: a. UNIX b. Android c. iOS d. Mac OS X
c. iOS
The _______ process is assigned as the parent to orphan processes. Select one: a. zombie b. main c. init d. renderer
c. init
Which of the following contains the addresses of all the service routines? Select one: a. file descriptor table b. page table c. interrupt vector d. system call table
c. interrupt vector
A(n) _________ page table has one page entry for each real page (or frame) of memory. Select one: a. clustered b. forward-mapped c. inverted d. virtual
c. inverted
WAFL (write-anywhere file layout) Select one: a. cannot provide files via NFS b. can provide files via NFS, but not via CIFS c. is a distributed file system d. is a file system dedicated to single user operating systems
c. is a distributed file system
A free-frame list Select one: a. is a set of all frames that are used for stack and heap memory. b. is a set of all frames that are filled with all zeros. c. is a set of all frames that are currently unallocated to any process. d. is a set of all frames that are currently being shared by at least two processes.
c. is a set of all frames that are currently unallocated to any process.
A 64-bit architecture with more than 16 quintillion addressable memory Select one: a. can support a majority of today's application requirements, but not all. b. All of the above. c. is large enough to support all current application requirements but may not be able to support all future application requirements. d. is large enough to support all current as well as future application requirements.
c. is large enough to support all current application requirements but may not be able to support all future application requirements.
Which systems record each metadata update to the file system as a transaction Select one: a. consistency checking b. bootstrap restart c. journaling d. transaction monitor
c. journaling
An address generated by a CPU is referred to as a ____. Select one: a. physical address b. post relocation register address c. logical address d. Memory-Management Unit (MMU) generated address
c. logical address
The _____ model maps many user-level threads to one kernel thread. Select one: a. two-level b. one-to-one c. many-to-one d. many-to-many
c. many-to-one
The current directory is Select one: a. none of the other answers b. always included in the search path c. may be included in the search path d. represented by the symbol ".."
c. may be included in the search path
A full bootstrap program Select one: a. runs after the operating system has been loaded in memory. b. is part of an operating system c. may be infected by viruses. d. is stored in ROM to ensure to avoid any infection from viruses.
c. may be infected by viruses.
A page out operation Select one: a. deletes a page from the backing store. b. moves a page from one frame to another. c. moves a page from memory to the backing store. d. moves a page from the backing store to memory.
c. moves a page from memory to the backing store.
Windows uses the ____. Select one: a. many-to-one-model b. many-to-many model c. one-to-one model d. one-to-many model
c. one-to-one model
In systems that support virtual memory, _______________________. Select one: a. physical memory is separated from secondary storage b. virtual memory is separated from logical memory c. physical memory is separated from logical memory d. virtual memory is separated from physical memory
c. physical memory is separated from logical memory
The protection bit in a page table Select one: a. All of the above. b. marks a frame as read-only or read-write. c. provides protection against unauthorized updates in the page table. d. marks a page table as read-only or read-write.
c. provides protection against unauthorized updates in the page table.
The basic file systems _______________ Select one: a. tracks unallocated blocks and provides them the when it is required. b. manages directory structure. c. reads and writes physical blocks on the storage device. d. is responsible for protection.
c. reads and writes physical blocks on the storage device.
Stateless File Servers: Select one: a. are very secure. b. track which clients have exported volumes. c. require that each client request is self-contained, i.e., all information needed to locate the file and perform the requested operation is given. d. maintain states of all open files.
c. require that each client request is self-contained, i.e., all information needed to locate the file and perform the requested operation is given.
Which of the following process state will be switched from "ready" state? Select one: a. ready b. waiting c. running d. terminated
c. running
Which of the following memory space dynamically grows from high memory to low memory? Select one: a. data section b. text section c. stack section d. heap section
c. stack section
A significant problem with priority scheduling algorithms is _____. Select one: a. determining the length of the time quantum b. complexity c. starvation d. determining the length of the next CPU burst
c. starvation
Which of the following contains the executable code? Select one: a. stack section b. heap section c. text section d. data section
c. text section
A relative path name defines a path from_________________________ Select one: a. the root directory b. from the MFD (master file directory) c. the current directory d. from the UFD (user file directory)
c. the current directory
Counting based page replacement algorithms are not commonly used, because Select one: a. they only approximate LRU. b. they are expensive to implement, even though they incur the least number of page faults. c. they do not approximate OPT replacement very well and their implementation is expensive. d. they do not approximate OPT replacement very well, even though they are easy to implement.
c. they do not approximate OPT replacement very well and their implementation is expensive.
A ____ provides an API for creating and managing threads. Select one: a. set of system calls b. multi-core system c. thread library d. multi-threading model
c. thread library
The default scheduling class for a process in Solaris is ____. Select one: a. system b. real-time c. time sharing d. interactive
c. time sharing
A boot block __________. Select one: a. typically is sophisticated enough to load the operating system and begin its execution b. is composed of multiple disk blocks c. typically only knows the location and length of the rest of the bootstrap program d. is composed of multiple disk cylinders
c. typically only knows the location and length of the rest of the bootstrap program
In multithreaded programs, the kernel informs an application about certain events using a procedure known as a(n) ____. Select one: a. pool b. signal c. upcall d. event handler
c. upcall
Which of the following circumstances can preemptive scheduling take place? Select one: a. when a process terminates b. when a process switches from the running state to the waiting state c. when a process switches from the waiting state to the ready state d. none of the other answers
c. when a process switches from the waiting state to the ready state
The _________ is an approximation of a program's locality. Select one: a. locality model b. page fault frequency c. working set d. page replacement algorithm
c. working set
In file systems consistent with UNIX semantics: Select one: a. a file cannot be opened by one user only. b. users cannot share the pointer of current location into a file. c. writes to a file by a user are immediately visible to other users that have this file open. d. writes performed by one user are not seen by other users .
c. writes to a file by a user are immediately visible to other users that have this file open.
Benefit(s) of using STREAMS is (are) Select one: a. All the other choices b.number of modules in STREAMS is constant. c.a module can be used by more than one device. d.STREAMS I/O is synchronous.
c.a module can be used by more than one device.
A sense key reports on the failure of a SCSI device by ____. Select one: a.giving detailed information about the exact cause of failure b.stating the general category of failure c.stating the general nature of the failure d.maintaining internal pages of error-log information
c.stating the general nature of the failure
A(n) ____ is a front-end processor that multiplexes the traffic from hundreds of remote terminals into one port on a large computer. Select one: a.network daemon b. I/O channel c.terminal concentrator d.context switch coordinator
c.terminal concentrator
A character-stream device ____. Select one: a. is a device such as a disk drive b.transfers data in blocks of bytes c.transfers data a byte at a time d. is similar to a random access device
c.transfers data a byte at a time
Which of the following scheduling algorithms gives the minimum average waiting time for a given set of processes? Select one: a. FCFS b. Multilevel queue c. RR d. SJF
d. SJF
When mutex lock is implemented as a binary semaphore, what should its value be initialized to be? Select one: a. none of the other answers b. 0 c. -1 d. 1
d. 1
Given the reference string of page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 3 and a system with three page frames, what is the final configuration of the three frames after the OPT algorithm is applied? Select one: a. 1, 3, 4 b. 2, 3, 4 c. 1, 2, 1 d. 1, 2, 3
d. 1, 2, 3
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. all of the above c. 1551 d. 1200
d. 1200
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. 4, 1, 2 b. 1, 3, 4 c. 1, 2, 3 d. 3, 1, 4
d. 3, 1, 4
Using ____-bit pointers limits the size of a file to 4 GB. Select one: a. 64 b. 128 c. 256 d. 32
d. 32
UNIX systems consider each file to be a sequence of _______________ Select one: a. bit words, which length is defined by the users b. 32 bit words c. 16 bit words d. 8-bit bytes
d. 8-bit bytes
A frame table stores Select one: a. which frames are allocated. b. total number of frames. c. which frames are free. d. All of the above.
d. All of the above.
Why is a directory structure needed? Select one: a. To retain meta data about a file b. To locate a file c. To provide structure to the layout of the file system d. All of the other answers
d. All of the other answers
Which of the following would be an acceptable signal handling scheme for a multithreaded program? Select one: a. Deliver the signal to only certain threads in the process. b. Deliver the signal to every thread in the process. c. Deliver the signal to the thread to which the signal applies. d. All the other answers
d. All the other answers
In modern operating systems, dynamic loading and unloading allows Select one: a.adding new I/O devices without recompiling the kernel. b.updating existing devices drivers without recompiling the kernel. c.adding new I/O devices after the system has already been booted. d. All the other choices
d. All the other choices
___________ is a formula that identifies potential performance gains from adding additional computing cores to an application that has a parallel and serial component. Select one: a. Data splitting b. Data parallelism c. Task parallelism d. Amdahl's Law
d. Amdahl's Law
An advantage of SSDs over HDDs is Select one: a. SSD have more write capability than HDD's b. SSDs are more reliable than HDDs. c. SSDs are cheaper per megabyte than HDDs. d. SSDs are faster than HDDs.
d. SSDs are faster than HDDs.
A _________________ saves the state of the currently running process and restores the state of the next process to run. Select one: a. save-and-restore b. None of the other answers c. state switch d. context switch
d. context switch
Which of the following statements is most correct. Select one: a. An operating system consists of the necessary software components to facilitate the usage of your computer including the graphical user interface but not the included utility programs. b. An operating system consists of everything you get when you buy your computer. c. An operating system consists of the necessary software components to facilitate the usage of your computer including the graphical user interface and included utility programs. d. An operating system consists of the necessary software components to facilitate the usage of your computer but not necessarily the graphical user interface or included utility programs.
d. An operating system consists of the necessary software components to facilitate the usage of your computer but not necessarily the graphical user interface or included utility programs.
What is the single best method of recovery Select one: a. Error correction code b. Checksums c. Journaling d. Backup
d. Backup
_________ is the dynamic storage-allocation algorithm which results in the smallest leftover hole in memory. Select one: a. Worst fit b. First fit c. None of the other answers d. Best fit
d. Best fit
If the starting address location changes, in which of the following cases, the program has to be recompiled? Select one: a. Load time binding. b. Execution time binding. c. Both compile and load time bindings. d. Compile time binding
d. Compile time binding
Which of the following does not increase the TLB reach? Select one: a. Provide multiple page sizes. b. Increase the size of TLB. c. Increase page size. d. Decrease the size working set.
d. Decrease the size working set.
Which scheduling criteria is the most important? Select one: a. Throughput b. Waiting Time c. Response Time d. Depends on the system needs e. Turnaround Time f. CPU Utilization
d. Depends on the system needs
Which of the following technology reduces the overhead for bulk data movement? Select one: a. Storage Area Network (SAN) b. Non-uniform Memory Access (NUMA) c. Symmetric Multiprocessing (SMP) d. Direct Memory Access (DMA)
d. Direct Memory Access (DMA)
Which of the following scheduling algorithms must be nonpreemptive? Select one: a. RR b. priority algorithms c. SJF d. FCFS
d. FCFS
____ is a thread library for Solaris that maps many user-level threads to one kernel thread. Select one: a. Sthreads b. Pthreads c. Java threads d. Green threads
d. Green threads
Which of the following is TRUE about NAS and Cloud storage? Select one: a. Cloud storage is typically accessed over a LAN while NAS is accessed over a WAN. b. all of the other answers. c. Cloud storage is accessed like a file system while NAS is API based. d. In an event of temporary network disconnection, an application using NAS will typically hang while an application using cloud storage will typically pause.
d. In an event of temporary network disconnection, an application using NAS will typically hang while an application using cloud storage will typically pause.
In what way is an operating system like a government? Select one: a. It is always concerned primarily with the individual's needs. b. It performs most useful functions by itself. c. It seldom functions correctly. d. It creates an environment within which other programs can do useful work.
d. It creates an environment within which other programs can do useful work.
Flash Memory makes for good swap space because: Select one: a. Flash memory is faster than magnetic media. b. Flash memory is persistent. c. It has no moving parts, so there is no seek time or latency. d. It does not make for good swap space.
d. It does not make for good swap space.
What is the purpose of the mutex semaphore in the implementation of the bounded-buffer problem using semaphores? Select one: a. It indicates the number of empty slots in the buffer. b. It indicates the number of occupied slots in the buffer. c. It controls access to the shared buffer. d. It ensures mutual exclusion.
d. It ensures mutual exclusion.
Simply, what is Virtual Memory? Select one: a. It is using all the memory pyramid b. It is a guarantee of how much memory there is. c. It is memory that does not exist. d. It is an abstraction of the physical memory.
d. It is an abstraction of the physical memory.
Which of the following statement is correct? Select one: a. Any attempt by a user program to access memory at an address higher than the base register value results in a trap to the operating system. b. Base register holds the size of a process. c. Base and limit registers can be loaded by the standard load instructions in the instruction set. d. Limit register holds the size of a process.
d. Limit register holds the size of a process.
____ operating systems are designed primarily to maximize resource utilization. Select one: a. Handheld computer b. PC c. Network d. Mainframe
d. Mainframe
The average external fragmentation is: Select one: a. It is twice the block size b. It is 1/2 the total space minus the allocated space c. It is 1/2 the block size d. None of the other answers
d. None of the other answers There is no easy measure for external fragmentation as it is dependent on file sizes, creation and deletion activity and block sizes. On the other hand the average internal fragmentation is 1/2 the block size.
Which of the following statements is incorrect? Select one: a. Operating systems must provide both protection and security. b. An operating system manages system resources. c. An operating system provides an environment for the execution of programs. d. Operating systems provide both command line as well as graphical user interfaces.
d. Operating systems provide both command line as well as graphical user interfaces.
Which of the following statements is true? Select one: a. Operations on atomic integers do require additional locking. b. Linux only provides the atomic_inc() and atomic_sub() operations. c. Operations on atomic integers can be interrupted. d. Operations on atomic integers do not require locking.
d. Operations on atomic integers do not require locking.
Which of the following criteria is more important for an interactive system? Select one: a. CPU utilization b. Turnaround time c. Throughput d. Response time
d. Response time
Which of the following statements regarding threads is false? Select one: a. The start() method actually creates a thread in the Java virtual machine. b. The Java method join() provides similar functionality as the WaitForSingleObject in Win32. c. Both Pthreads and Win32 threads share global data. d. Sharing is automatically provided in Java threads.
d. Sharing is automatically provided in Java threads.
____ involves the decision of which kernel thread to schedule onto which CPU. Select one: a. Dispatcher b. Process-contention scope c. Round-robin scheduling d. System-contention scope
d. System-contention scope
The _____ is the number of entries in the TLB multiplied by the page size. Select one: a. hit ratio b. TLB Cache c. page resolution d. TLB reach
d. TLB reach
_________ involves distributing tasks across multiple computing cores. Select one: a. Parallelism b. Data parallelism c. Concurrency d. Task parallelism
d. Task parallelism
What information is required to mount a file system? Select one: a. The file system type and the mount point b. The name of the device containing file system and the file system type c. Only the name of the device d. The name of the device containing file system, file system type and the mount point
d. The name of the device containing file system, file system type and the mount point
Which of the following is FALSE about streams? Select one: a. A stream is a full-duplex connection between a device driver and a user-level process. b. Messages may be dropped in a stream even if flow control is implemented. c. Each stream module contains a pair of queues. d. The number of modules in a stream is fixed by the operating system.
d. The number of modules in a stream is fixed by the operating system.
____ is the number of processes that are completed per time unit. Select one: a. Turnaround Time b. CPU utilization c. Response Time d. Throughput
d. Throughput
Some binary files can include a magic number. This mechanism is used by __________. Select one: a. macOS b. JavaVM c. MS Windows d. UNIX
d. UNIX
_____ can be used to prevent busy waiting when implementing a semaphore. Select one: a. Mutex lock b. Allowing the wait() operation to succeed c. Spinlocks d. Waiting queues
d. Waiting queues
_________ is the dynamic storage-allocation algorithm which results in the largest leftover hole in memory. Select one: a. First fit b. None of the other answers c. Best fit d. Worst fit
d. Worst fit
Which of the following is the definition of processor? Select one: a. the hardware that executes instructions b. the basic computation unit of the CPU c. including multiple computing cores on the same CPU d. a physical chip that contains one or more CPUs
d. a physical chip that contains one or more CPUs
A file handle is: Select one: a. a pointer to a logical address of a file b. a pointer to the file use directory c. a pointer to a physical address of a file d. a pointer to an entry in the per-process file system table
d. a pointer to an entry in the per-process file system table A file handle is an index or pointer to an in memory control bock used to keep track of a files information while open
A(n) ______ matches the process with each entry in the TLB. Select one: a. page number b. stack c. process id d. address-space identifier
d. address-space identifier
Indexed allocation Select one: a. supports direct access b. does not suffer from external fragmentation. c. none of the other answers d. all of the other answers
d. all of the other answers
Which of the following are used by Linux kernel as data structures? Select one: a. Lists, Stacks, and Queues b. Trees c. Hash Functions and Maps d. all of the other answers e. Bitmaps
d. all of the other answers
Which of the following models are possible for the relationship between the user threads and kernel threads? Select one: a. one-to-one model b. many-to-one model c. many-to-many model d. all of the other answers e. two-level model
d. all of the other answers
Acyclic-graph directory structure_______________________ Select one: a. prohibits the sharing of files and directories b. prohibits the sharing of files, but allows to share directories c. allows the sharing of files, but prohibits to share directories d. allows to share files and directories
d. allows to share files and directories
Which of the following components of a computer system defines the ways to use system resources to solve computing problems? Select one: a. computer hardware b. computer logo c. operating system d. application programs
d. application programs
The major difficulty in designing a layered operating system approach is ____. Select one: a. making sure that each layer hides certain data structures, hardware, and operations from higher-level layers b. making sure each layer is easily converted to modules c. debugging a particular layer d. appropriately defining the various layers
d. appropriately defining the various layers
Which of the following variables are shared between the processes in Peterson's solution? Select one: a. boolean flag[2] b. none of the other answers c. int turn d. both of the above
d. both of the above
Which of the following is NOT a technique used for managing power consumption in mobile devices? Select one: a. Wakelocks. b. Power collapse. c. Component level power management. d. chilling with natural sources such as lake water, and solar panels.
d. chilling with natural sources such as lake water, and solar panels.
Which of the following is loosely coupled? Select one: a. multi-core processor b. single-processor system c. multiprocessor systems d. clustered system
d. clustered system
With ____ a thread executes on a processor until a long-latency event (i.e. a memory stall) occurs. Select one: a. virtualization b. fine-grained multithreading c. multicore processors d. coarse-grained multithreading
d. coarse-grained multithreading
A _____ is an example of a systems program. Select one: a. text formatter b. web browser c. database system d. command interpreter
d. command interpreter
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. Select one: a. status b. transfer c. data-in d. control
d. control
______________ allows the parent and the child process to initially share the same pages, but when either process modifies a page, a copy of the shared page is created. Select one: a. memory-mapping b. zero-fill-on-demand c. virtual memory fork d. copy-on-write
d. copy-on-write
In a swap map in Linux Select one: a. counter value 0 indicates that the page slot is occupied by a swapped page. b. counter value -1 indicates that the page slot is available. c. counter value -5 indicates that the page slot was occupied by a page that was shared by five processes, and is now available. d. counter value 5 indicates that the page slot is occupied and the page is shared by five processes.
d. counter value 5 indicates that the page slot is occupied and the page is shared by five processes.
Policy __________. Select one: a. is not likely to change across places b. is not likely to change over time c. determines how to do something d. determines what will be done
d. determines what will be done
The CPU catches the interrupt and ____ it to the interrupt handler Select one: a. raises b. catches c. clears d. dispatches
d. dispatches
Low-level formatting ____. Select one: a. is different from physical formatting b. does not usually provide an error-correcting code c. is usually performed by the purchaser of the disk device d. divides a disk into sections that the disk controller can read and write
d. divides a disk into sections that the disk controller can read and write
A deadlocked state occurs whenever ____. a process is waiting for I/O to a device that does not exist Select one: a. a process is waiting for I/O to a device that does not exist b. a process is unable to release its request for a resource after use c. the system has no available free resources d. every process in a set is waiting for an event that can only be caused by another process in the set
d. every process in a set is waiting for an event that can only be caused by another process in the set
The ________ application is the application appearing on the display screen of a mobile device. Select one: a. display b. main c. background d. foreground
d. foreground
Which of the following contains dynamically allocated data during program run time? Select one: a. text section b. data section c. stack section d. heap section
d. heap section
Which of the following contains memory allocated by malloc()? Select one: a. stack section b. text section c. data section d. heap section
d. heap section
The most common technique for writing multithreaded Java programs is _____. Select one: a. using the CreateThread() function b. designing your own Thread class c. extending the Thread class and overriding the run() method d. implementing the Runnable interface and defining its run() method
d. implementing the Runnable interface and defining its run() method
A process control block ____. Select one: a. stores the address of the next instruction to be processed by a different process b. is an example of a process queue c. determines which process is to be executed next d. includes information on the process's state
d. includes information on the process's state
Where is the location of L1 cache? Select one: a. inside processor but outside CPU core b. inside main memory c. inside registers d. inside CPU core
d. inside CPU core
Which of the following stage triggers the CPU switch from user program to interrupt processing? Select one: a. interrupt handled b. transfer done c. I/O request d. interrupt signaled
d. interrupt signaled
A mutex lock ____. Select one: a. is not guaranteed to be atomic b. can be used to eliminate busy waiting c. is exactly like a counting semaphore d. is essentially a boolean variable
d. is essentially a boolean variable
Optimal page replacement ____. Select one: a. is the page-replacement algorithm most often implemented b. requires that the system keep track of previously used pages c. can suffer from Belady's anomaly d. is used mostly for comparison with other page-replacement schemes
d. is used mostly for comparison with other page-replacement schemes
Which of the following programs runs all the time on the computer? Select one: a. compiler b. text editor c. assembler d. kernel
d. kernel
The information about a file as owner, group, rights etc. are stored Select one: a. globally, in in-memory structure maintained by the operating system b. globally, in the global on-disk structure for each file system c. globally, in the global on-disk structure stored maintained by the operating system d. locally, with other file attributes
d. locally, with other file attributes
The _____ model multiplexes many user-level threads to a smaller or equal number of kernel threads. Select one: a. two-level b. one-to-one c. many-to-one d. many-to-many
d. many-to-many
In the two-level directory, if a user refers to a particular file then__________________ Select one: a. first MFD (master file directory) is searched, then UFD (user file directory) b. first UFD (user file directory) is searched, then MFD (master file directory) c. only MFD (master file directory) is searched d. only his/her own UFD (user file directory) is searched
d. only his/her own UFD (user file directory) is searched
Suppose the size of a process is 10,000 bytes and the relocation register is loaded with value 5000, which of the following memory address this process can access? Select one: a. physical address 4,500 b. logical address 10,350 c. None of the above d. physical address 10,350
d. physical address 10,350
LWP is ____. Select one: a. placed between system and kernel threads b. short for lightweight processor c. common in systems implementing one-to-one multithreading models d. placed between user and kernel threads
d. placed between user and kernel threads
Device drivers Select one: a. manage only the basic I/O hardware elements b. manage only the newly emerging I/O devices that are unlike previous devices c. All the other answers d. present a uniform device- access interface to the I/O subsystem
d. present a uniform device- access interface to the I/O subsystem
What category of system call includes the ones for process creation of and termination? Select one: a. file management b. device management c. protection d. process control
d. process control
The two general approaches to load balancing are ____ and ____. Select one: a. soft real-time, hard real-time b. coarse grained, fine grained c. soft affinity, hard affinity d. push migration, pull migration
d. push migration, pull migration
Which of the following is NOT secondary storage device? Select one: a. magnetic tape b. optical disk c. solid state disks d. random access memory
d. random access memory
The list of processes waiting to execute on a CPU is called a(n) ____. Select one: a. device queue b. standby queue c. interrupt queue d. ready queue
d. ready queue
Which of the following computing environments place rigid time requirements on the operation of a processor or the flow of data? Select one: a. peer-to-peer computing b. traditional computing c. client-server computing d. real-time embedded system
d. real-time embedded system
A race condition ______. Select one: a. will result only if the outcome of execution does not depend on the order in which instructions are executed b. None of the other answers c. results when several threads try to access the same data concurrently d. results when several threads try to access and modify the same data concurrently
d. results when several threads try to access and modify the same data concurrently
Which of the following items does not belong to the function of a dispatcher? Select one: a. switching to user mode b. switching context from one process to another c. jumping to the proper location in the user program to resume that program d. selecting a process among the available ones in the ready queue
d. selecting a process among the available ones in the ready queue
When the shared lock is applied to a file then ____________ Select one: a. many processes can read and write to this file concurrently b. many processes can write to this file concurrently c. only one process can use this file d. several processes can acquire the lock concurrently
d. several processes can acquire the lock concurrently
Which of the following is the only gateway between user space and kernel space? Select one: a. user interface b. hardware drivers c. operating system d. system call
d. system call
The Linux CFS scheduler identifies _____________ as the interval of time during which every runnable task should run at least once. Select one: a. load balancing b. nice value c. virtual run time d. targeted latency
d. targeted latency
Anonymous memory of a process refers to Select one: a. the pages associated with the static data of the process. b. the pages associated with the binary executable file of the process. c. the pages that cannot be swapped out of the physical memory. d. the pages not associated with the binary executable file of the process.
d. the pages not associated with the binary executable file of the process.
When the file system contains more than one bootable partition, then Select one: a. a boot loader is parallel searching each partition for kernel and runs the first found b. all available operating systems are booted at the same time c. the system cannot contain more than one bootable partition d. the system administrator (admin user) selects which operating system will be booted
d. the system administrator (admin user) selects which operating system will be booted
The x86-64 architecture provides support for Select one: a. three different page sizes using 3-level paging hierarchy. b. four different page sizes using 3-level paging hierarchy. c. four different page sizes using 4-level paging hierarchy. d. three different page sizes using 4-level paging hierarchy.
d. three different page sizes using 4-level paging hierarchy.
The _____ model allows a user-level thread to be bound to one kernel thread. Select one: a. many-to-many b. many-to-one c. one-to-one d. two-level e. one-to-many
d. two-level
If an instruction modifies several different locations, a page fault can be handled by Select one: a. loading multiple pages in advance. b. terminating the process. c. incorporating special hardware. d. using temporary registers to hold the values of overwritten locations.
d. using temporary registers to hold the values of overwritten locations.
Which UNIX inodes and/or vnodes used by the Virtual File System (VFS) have a file representation structure? Select one: a. UNIX inodes are not unique designators for a single file system. b. vnodes are unique file designators for remote file systems only. c. UNIX inodes and vnodes are unique designators within a single file system only. d. vnodes are wide network unique file designators.
d. vnodes are wide network unique file designators.
Which of the following is true about I/O implementation? Select one: a.A specialized implementation in hardware is highly flexible. b.Implementation at the application level provides the highest performance benefits. c.An in-kernel implementation avoids the need to reboot or reload device drivers after every change to the code. d.An in-kernel implementation can cause data corruption and system crashes.
d.An in-kernel implementation can cause data corruption and system crashes.
Which of the following is true of a blocking system call? Select one: a.The application continues to execute its code when the call is issued. b.Blocking application code is harder to understand than nonblocking application code c.The call returns immediately without waiting for the I/O to complete. d.The execution of the application is suspended when the call is issued.
d.The execution of the application is suspended when the call is issued.
Which of the following system architectures involves multiprocessor scheduling? Select one: a. NUMA systems b. heterogeneous multiprocessing c. multicore CPUs d. multithreaded cores e. all of the other answers
e. all of the other answers
Given a logical address of 0x9E7 and a page size of 256 bytes and given the page table below, what is the result of the memory access? Page TableFrameValidity Bit0x9v0x14v0xAv0x21v0x2v0x7v0xCv0x22v0x24v0x27i0x23v0x1i0i0i0i Select one: a. It references physical memory address of 0x27E7. b. It references physical memory address of 0x24E7. c. None of the other answers d. It references physical address 0x24E7 which is not a valid page and causes a page fault. e. It references physical memory address of 0x279E7. f. It references physical address 0x27E7 which is not a valid page and causes a page fault.
f. It references physical address 0x27E7 which is not a valid page and causes a page fault.
Suppose we have the following page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 4 and that there are three frames within our system. Using the LRU replacement algorithm, what is the number of page faults for the given reference string? Select one: a. 6 b. 9 c. 14 d. 11 e. 10 f. 7 g. 13 h. 8
h. 8
best describes the action of seek.
moving the file pointer to a specified position
If an architecture has a move instruction with more than one word and at most one of the two operands may be an indirect memory reference, the minimum number of frames needed to run a process on this architecture is Select one: a. 4 b. 6 c. 3 d. 5
not b
In a blocking system call, the execution of a process is suspended Select one: a. the kernel raises the priority of that process. b. until a fixed amount of time has elapsed. c. until the process is woken up by some other process. d. the I/O has completed.
not c
Which of the following is TRUE about a serial port controller and a fibre channel (FC) bus controller? Select one: a. Both FC bus controller and serial port controller are used in PCs. b. Both FC bus controller and serial port controller are often implemented as separate circuit boards. c. All of the other options. d. A serial-port controller is a simple device controller, while an FC bus controller is complex.
not c not b
A control register in an I/O device control Select one: a. contains status bits that can be read by the host. b. is read by the host to get input. c. is written by the host to choose half-duplex communication. d. is written by the host to send output.
not c not d
In Additional-Reference-Bits algorithm, Select one: a. None of the above. b. the least-recently used page is identified very efficiently on a page fault. c. a group of pages that have not been used recently are efficiently identified. d. a page that has been referenced most recently is identified.
not d
In memory-mapped I/O Select one: a. address space of the computing device is used for communicating with the I/O devices using the standard I/O instructions. b. main memory of the computing device is used for communicating with the I/O devices using the special I/O instructions. c. main memory of the computing device is used for communicating with the I/O devices using the standard I/O instructions. d. address space of the computing device is used for communicating with the I/O devices using the special I/O instructions.
not d
The Second-Chance algorithm Select one: a. is same as LRU algorithm if none of the pages in memory have been referenced since the last page fault. b. is same as LRU algorithm if all pages in memory have been referenced at least once since the last page fault. c. is same as FIFO algorithm if all pages in memory have been referenced at least once since the last page fault. d. is same as FIFO algorithm if none of the pages in memory have been referenced since the last page fault.
not d
