Define latency, transfer and seek time with respect to disk I/O.

Correct Answer: User data: Modifiable part of user space May include program data, user stack area, and programs that may be modified User program: The instructions to be executed System Stack: Each process has one or more LIFO stacks associated with it Used to store parameters and calling addresses for procedure and system calls Process control Block (PCB): Info needed by the OS to control processes

Correct Answer: In message passing, it is the condition in which, both, the sender and receiver are blocked until the message is delivered

Correct Answer: Graphical

Correct Answer: Commonly, the different attributes for a file structure are naming,size, identifier, a level of protection, supported file types and location for the files

Correct Answer: When a thread is created the threads does not require any new resources to execute the thread shares the resources like memory of the process to which they belong to The benefit of code sharing is that it allows an application to have several different threads of activity all within the same address space Whereas if a new process creation is very heavyweight because it always requires new address space to be created and even if they share the memory then the inter process communication is expensive when compared to the communication between the threads

Correct Answer: A binary semaphore is one, which takes only 0 and 1 as values They are used to implement mutual exclusion and synchronize concurrent processes

Correct Answer: swapping interactive user request timing parent process request

Correct Answer: Load Sharing: Processes are not assigned to a particular processor A global queue of threads is maintained Each processor, when idle, selects a thread from this queue Note that load balancing refers to a scheme where work is allocated to processors on a more permanent basis Gang Scheduling: A set of related threads is scheduled to run on a set of processors at the same time, on a 1-to-1 basis Closely related threads / processes may be scheduled this way to reduce synchronization blocking, and minimize process switching Group scheduling predated this strategy Dedicated processor assignment: Provides implicit scheduling defined by assignment of threads to processors For the duration of program execution, each program is allocated a set of processors equal in number to the number of threads in the program Processors are chosen from the available pool Dynamic scheduling: The number of thread in a program can be altered during the course of execution

Correct Answer: Kernel follows Round Robin scheme choosing a swap device among the multiple swap devices in Unix System V

Correct Answer: The repeated execution of a loop of code while waiting for an event to occur is called busy-waiting The CPU is not engaged in any real productive activity during this period, and the process does not progress toward completion