. What trouble arises it a kernel code which has acquired a spin lock is interrupted by an
Interrupt handler trying to acquire the same spin lock? is it possible to avoid such a

situation? How? (6)

. What is the difference between vmallocO and kmallcc()? Which of these must be
used

for allocating memory for hardware devices? Why? (4.5)
a. What is the purpose of using reader-writer locks? (3)
b. How is a mutex different from a semaphore? (3)

. Explain the following. (2 +2.5)
a) Per CPU Allocation.
b) Dentry object
Part C

. What is the difference between a block device and a character device? Give examples.
(2)

. What is the role of an 1/0 scheduler? (2.5)

. How can a client and server communicate with each other? What are the

major issues, advantages and disadvantages associated with each of them?

(6)

. Before the 2.6 kernel, buffer head was used for block ١/0 whereas in the later kernels. it
has been replaced by biostructure as the basic container for block I/O. Why? (4.5)

. Represent a consistent and inconsistent global state for the following
process/event

graph. (3)