OSG ben ngoai`

B

11.In a directed graph used to model deadlock, processes are represented using [A] Rectangle [B] Circular [C] Squares [D] Ellipse

4.7

12.A single-sided, single-layer DVD can hold ____ GB.

D

13.Programmed I/O should be acceptable for which of the following systems? Interactive systems Multiprogramming systems Embedded systems None of the other choices

d

23.The ways that input/output can be done is? a, Busy waiting b, Interrupt c, DMA d. All of the above

c

24.Assume jobs A-D arrive in quick succession in the READY queue. Using round robin scheduling (quantum=4), the turnaround time for job D is ____. Arrival time: 0 1 2 3 Job: A B C D CPU cycle: 8 4 9 5 a. 7 b. 20 c. 22 d. 24

D

29.Dijkstra's Banker's Algorithm require the system to maintain the resource information for each process, including: a. A count of the system's total resources b. The maximum resources that can be requested by the process c. The number of resources currently acquired by the process d. B and C

b

30.A CPU may have multiple execution units, so that can carry out multiple instructions in the same time is called: a. Pipeline b. Superscalar c. Multicore d. None of the other choices

d

31.In some thread systems, a thread want be blocked until an other thread has exited. It can establish this goal by calling______ thread_create thread_exit thread_wait d.thread_yield

best fit

32. In term of storage utilization, best method...

A

33.The scheme of ____ removes the possibility of a circular wait and therefore guarantees the removal of deadlocks. a. Hierarchical ordering b. Preemption c. Saving and restoring job state d. Requesting all resources before job run

C

34.occurs when two processes do not release control of resources they are using. A) No preemption B) Circular wait C) Resource holding D) Mutual exclusion

B

36.Which of the following conditions that causes the processes to be terminated, when the processes have a program bug? A. Normal exit (voluntary ) B. Error exit (voluntary) C. Fatal error (involuntary) D. Killed by another process (involuntary)

D

37.Which of the following is true about Atomic action on semaphores? a. Checking the value b. Changing the value c. Possibly going to sleep d. All of the other choices

A

38.One of the primary disadvantages of contiguous storage is that ____. A.It is hard to implement and manage B.It is difficult to find information in files C.File can't be expanded unless there is empty space available immediately following it D.It is an inefficient use of space

b

40.Which of the following is specified to indicate the directory where the file is located? a. Extension b. Path name c. Root directory d. Sub-directory

18msec

41.Đéo có chỉ có câu tương tự chắc là

c

42.What is not correct about system calls? a. A system call allows a user process to assess and execute operating system functions inside the kernel. b. User programs use system calls to invoke operating system services c. In terms of performance, using system calls is better than using procedure calls d. Every system call involves overhead due to context switch

c

43.As one proceeds down the memory hierarchy(phân cấp bộ nhớ) (from inboard memory to offline storage), which of the following conditions is correct? a. Increasing cost per bit b. Decreasing capacity c. Increasing access time d. None of the other choices

a

45.What is the table where its entry contains the memory address of Interrupt service routine a. Interrupt vector table b. Interrupt table c. Address table d. Address lines table

d

46.Increasing file system performance is implemented by _____ a. Buffer cache b. Block Read Ahead c. Defragmenting Disks d. All of the other choices

D

48.What is the correct approach of the driver of dedicated devices with requesting device that is busy to solve deadlock using Ostrich algorithm? [A] The device driver stops the current jobs and releases the devices [B] The device driver kills those requesting processes [C] All of the other choices [D] The device driver decides blocking and returning an error code

c

49.Which of the following synchronization mechanisms does not rely on busy -waiting ? a. Lock variables b. Strict alternation c. Peterson's algorithm d. Semaphores

d

52How many percent of the CPU time is wasted, when a computer system has enough room to hold two program and these programs are idle waiting for I/O 10% of the time? [A] 90% [B] 99% [C] None of the other choices [D] 1 %.

d

53.If a system is deadlocked, no processes can a. run b. release resources c. be awakened d. All of the other choices

c

54.Which of the following is not special file? [A] None of the other choices [B] Block special file [C] Character special file [D] Stream special file

b

55. How much cylinder skew is needed for a 7200- RPM (rotate per minute) disk with the track-to-track seek time of 1 msec? The disk has 200 sectors of 512 bytes on each track. a. 24 sectors b. 12 sectors c. 36 sectors d. 18 sectors địt bà câu này nó thay = 3600 chắc đáp án là b

b

56.Which of the following information bits in the entry of page table is used to indicate Page Fault? A/ Status bit B/ Present/ Absent bit C/ Referenced bit D/ Modified bit

A

57. Imagine that a certain printer can print 400 characters per second and that the time to write a character to the printer's output register is so short it can be ignored. If to run this printer using interrupt-driven I/O and each character printed requires an interrupt that takes 50 µsec all-in to service. How many percent of the CPU does the interrupt overhead cost? a. 2% of the CPU b. 98% of the CPU c. 4% of the CPU d. 96% of the CPU

c

58.In a single processor system, mutual exclusion can be guaranteed by: (2314) a. Overlapping processes b. Interleaving processes c. Disabling interrupts d. All of the above

D

59.The Mach model of Page fault handling with an external pager includes A low-level MMU handler A page fault handler that is part of the kernel An external pager running in user space All of the other choices

A

7.Consider an i-node which contains 10 direct addresses of 4 bytes each and all disk blocks are 1 KB. Also consider that the i-node contains an additional "single and double indirect address" that is used for containing more disk block addresses. What is the largest possible file? A.65802 KB B.10 KB C.266 KB D.65536 KB