Quiznetik

Multi-core processors | Set 1

1. The idea of cache memory is based

Correct : C. . on the fact that references generally tend to cluster

2. Systems that do not have parallel processing capabilities are

Correct : D. . misd

3. Parallel programs: Which speedup could be achieved according to Amdahl´s law for infinite number of processors if 5% of a program is sequential and the remaining part is ideally parallel?

Correct : B. . 20

4. In shared bus architecture, the required processor(s) to perform a bus cycle, for fetching data or instructions is

Correct : C. . multi-processor

5. Alternative way of a snooping-based coherence protocol, is called a

Correct : C. . directory protocol

6. If no node having a copy of a cache block, this technique is known as

Correct : D. . valid data

7. All nodes in each dimension form a linear array, in the                  .

Correct : D. . mesh topology

8. tasks being performed in different stages :

Correct : A. . require different amount of time

9. The expression 'delayed load' is used in context of

Correct : C. . pipelining

10. During the execution of the instructions, a copy of the instructions is placed in the            .

Correct : C. . system heap

11. Producer consumer problem can be solved using

Correct : C. . monitors

12. A situation where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which access takes place is called:

Correct : B. . race condition

13. Which one of the following statements describes the properties achieved?

Correct : A. . mutual exclusion but not progress

14. All deadlocks involve conflicting needs for

Correct : A. . resources

15. To avoid deadlock

Correct : A. . there must be a fixed number of resources to allocate

16. processes to solve the critical section problem.

Correct : B. . two

17. Spinlocks are intended to provide                   only.

Correct : B. . bounded waiting

18. A semaphore is a shared integer variable                     .

Correct : B. . that cannot drop below zero

19. A critical section is a program segment                         .

Correct : D. . lower resource consumption

20. A counting semaphore was initialized to 10. Then 6 P (wait) operations and 4V (signal) operations were completed on this semaphore. The resulting value of the semaphore is

Correct : D. . 8

21. How many times will process P0 print '0'?

Correct : C. . three

22. A system has 3 processes sharing 4 resources. If each process needs a maximum of 2 units, then

Correct : C. . responsiveness

23. code, resources or data in such a way that only one process has access to shared object at a time.

Correct : C. . semaphores

24. is the ability of multiple processes to co-ordinate their activities by exchange of information.

Correct : A. . deadlock

25. Paths that have an unbounded number of allowed nonminimal hops from packet sources, this situation is referred to as                  .

Correct : C. . synchronization

26. Let S and Q be two semaphores initialized to 1, where P0 and P1 processes the following statements wait(S);wait(Q); ---; signal(S);signal(Q) and wait(Q); wait(S);---;signal(Q);signal(S); respectively. The above situation depicts a                .

Correct : C. . deadlock

27. Which of the following conditions must be satisfied to solve the critical section problem?

Correct : D. . all of the mentioned

28. a process is allowed to enter its critical section                     .

Correct : A. . after a process has made a request to enter its critical section and before the request is granted

29. processes to solve the critical section problem.

Correct : B. . two

30. What are Spinlocks?

Correct : D. all of the mentioned

31. What is the main disadvantage of spinlocks?

Correct : B. they require busy waiting

32. at any moment (the mutex being initialized to 1)?

Correct : C. 3

33. Here, w1 and w2 have shared variables, which are initialized to false. Which one of the following statements is TRUE about the above construct?

Correct : D. it does not prevent deadlocks but ensures mutual exclusion

34. The signal operation of the semaphore basically works on the basic              system call.

Correct : B. wakeup()

35. (not necessarily immediately)?

Correct : A. . #pragma omp section

36. When compiling an OpenMP program with gcc, what flag must be included?

Correct : A. . -fopenmp

37. program, i.e., each thread executes the same code.

Correct : A. . parallel

38. they would be in serial program.

Correct : B. . ordered

39. code of functions that are called (directly or indirectly) from within the parallel region.

Correct : C. . dynamic extent

40. The                          specifies that the iterations of the for loop should be executed in parallel by multiple threads.

Correct : B. . for pragma

41. active in the parallel section region.

Correct : B. . omp_get_num_threads ( )

42. The size of the initial chunksize                       .

Correct : A. . total_no_of_iterations / max_threads

43. parallel architectures affect parallelization?

Correct : C. . bandwidth

44. global_count += 5;

Correct : C. . 5 instructions

45. generate log files of MPI calls.

Correct : B. mpilog

46. selectively screen messages.

Correct : B. type

47. them in this case and returning the result to a single process.

Correct : A. mpi _ reduce

48. The easiest way to create communicators with new groups is with                      .

Correct : C. mpi_comm_split

49. is an object that holds information about the received message, including, for example, it’s actually count.

Correct : D. status

50. The                           operation similarly computes an element-wise reduction of vectors, but this time leaves the result scattered among the processes.

Correct : A. reduce-scatter

51. is applicable in ___________________.

Correct : A. . amdahl\s law

52. programming. The issues related to synchronization include the followings, EXCEPT:

Correct : C. . fairness

53. Interface (MPI)?

Correct : C. . only communicators and not groups are accessible to the programmer only by a "handle"

54. workload in the computation of the forces.

Correct : B. . velocity of each particle

55. parallelizing them using OpenMP.

Correct : D. . loop variable

56. Each node of the tree has an                              , that is, the cost of the partial tour.

Correct : C. . three-dimensional problems

57. could possibly lead to a least-cost solution.

Correct : C. . reduced algorithm

58. user program and buffersize is its size in bytes.

Correct : A. . tour data

59. addition to the cost of the communication, the packing and unpacking is very                            .

Correct : C. . expensive tours

60. has in its stack.

Correct : D. . empty

61. takes the data in data to be packed and packs it into

Correct : C. . mpi_datatype