CMU Final 2011

Question 1

Consider a direct-mapped cache memory. Which one of the following statements is true?
(a) The cache has 1 line per set.
(b) The cache has 1 word per block.
(c) The cache has 1 set per cache. (d)None of the above.

Answer 1

(a) The cache has 1 line per set.

Question 1

Which one of the following statements about cache memories is true:
(a) Larger caches are more susceptible to capacity misses than smaller caches.
(b) Caches with lower associativity are more susceptible to conflict misses than those with higher associativity.
(c) Caches with higher associativity are more susceptible to cold misses than those with lower associativity. (d)None of the above

Answer 1

(b) Caches with lower associativity are more susceptible to conflict misses than those with higher associativity.

Question 2

Which one of the following is NOT contained in an ELF executable file?
(a)Machine code
(b)Global variables
(c)User stack
(d) Symbol table

Answer 2

(c)User stack

Question 3

Assuming no errors, which one of the following statements about fork is true? (a) Called once, returns once.
(b) Called once, returns twice.
(c) Called once, returns never.
(d) Called twice, returns once. (e)None of the above.

Answer 3

(b) Called once,returns twice.

Question 4

Assuming no errors, which one of the following statements about execve is true?
(a) Called once, returns once.
(b) Called once, returns twice.
(c) Called once, returns never.
(d) Called twice, returns once. (e)None of the above.

Answer 4

(c) Called once, returns never.

Question 5

Which one of the following statements about processes is false?
(a) The operating system kernel runs as its own separate process.
(b) Each process shares the CPU with other processes.
(c) Each process has its own private address space.
(d) The environment for a process is stored on the stack.

Answer 5

(a) The operating system kernel runs as its own separate process.

Question 6

What happens if the parent of a zombie child terminates?
(a) The zombie child becomes a wraith and is never reaped.
(b) The zombie child is reaped by the init process.
(c) The zombie child is reaped by the process with the nearest PID. (d)None of the above.

Answer 6

(b) The zombie child is reaped by the init process.

Question 7

Suppose that the kernel delivers two SIGCHLD signals to the parent while the parent is not scheduled. When the kernel finally schedules the parent, how many times will the SIGCHLD handler be called? (a)None, because sending multiple signals will always crash the program.
(b) Exactly once, because signals are not queued.
(c) Exactly twice, because signals are queued. (d)More than twice, depending on how the handler is installed.

Answer 7

(b) Exactly once, because signals are not queued.

Question 8

Which one of the following statements is NOT true of storage allocators?
(a) In the best case, coalescing with boundary tags is linear in the number of free blocks.
(b) Seg lists typically approximate best fit search.
(c) Payloads must be aligned to some boundary.
(d) Explicit lists are typically faster than implicit lists.
(e)None of the above.

Answer 8

(a) In the best case, coalescing with boundary tags is linear in the number of free blocks.

Question 9

Which one of the following addresses is 8-byte aligned?
(a) 11101101011101112
(b) 11101101011101002
(c) 11101101011100002
(d) 11101101011101102
(e)Noneoftheabove

Answer 9

(c) 11101101011100002