Operating System |Gate-2006| Consider three CPU-intensive processes, which require 10, 20 and 30 time units and arrive at times 0, 2 and 6, respectively. How many context switches are needed if the operating system implements a shortest remaining time first scheduling algorithm? Do not count the context switches at time zero and at the end. …
Operating System |Gate-2006| previous year question|Set-15 Read More »
Operating System |Gate-2007| 1. Group 1 contains some CPU scheduling algorithms and Group 2 contains some applications. Match entries in Group 1 to entries in Group 2. [GATE – 2007] a. P – 3 Q – 2 R – 1b. P – 1 Q – 2 R – 3c. P – 2 Q – 3 …
Operating System |Gate-2007| previous year question|Set-14 Read More »
Operating System |Gate-2008| The data blocks of a very large file in the Unix file system are allocated using : [GATE – 2008] a. contiguous allocationb. linked allocationc. indexed allocationd. an extension of indexed allocation Answer : d) Which of the following statements about synchronous and asynchronous I/O is NOT true? [GATE – 2008] a. …
Operating System |Gate-2008| previous year question|Set-13 Read More »
Operating System |Gate-2009| In which one of the following page replacement policies, Belady’s anomaly may occur? [GATE – 2009] a. FIFOb. Optimalc. MRUd. LRU Answer : a) The essential content(s) in each entry of a page table is / are : [GATE – 2009] a. Virtual page numberb. Page frame numberc. Both virtual page number …
Operating System |Gate-2009| previous year question|Set-12 Read More »
Operating System |Gate-2010| 1. Which of the following statements are true? [GATE – 2010] a. I onlyb. I and III onlyc. II and III onlyd. I, II and III Answer : d) 2. Consider the methods used by processes P1 and P2 for accessing their critical sections whenever needed, as given below. The initial values …
Operating System |Gate-2010| previous year question|Set-11 Read More »
Operating System |Gate-2011| Let the page fault service time to 10 ms in a computer with average memory access time being 20 ns. If one page fault is generated for every 106 memory accesses, what is the effective access time for the memory? [GATE – 2011] a. 21 nsb. 30 nsc. 23 nsd. 35 ns Answer …
Operating System |Gate-2011| previous year question|Set-10 Read More »
Operating System |Gate-2012| 1. Consider the virtual page reference string 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 On a demand paged virtual memory system running on a computer system that main memory size of 3 pages frames which are initially empty. Let LRU, FIFO and OPTIMAL denote the number of page faults …
Operating System |Gate-2012| Previous year question|Set-9 Read More »
Operating System |Gate-2013| A computer uses 46-bit virtual address, 32-bit physical address, and a three-level paged page table organization. The page table base register stores the base address of the first-level table (T1), which occupies exactly one page. Each entry of T1 stores the base address of a page of the second-level table (T2). Each …
Operating System |Gate-2013| Previous year question|Set-8 Read More »
Operating System |Gate-2014| 1. Suppose a disk has 201 cylinders, numbered from 0 to 200. At some time the disk arm is at cylinder 100, and there is a queue of disk access requests for cylinders 30, 85, 90, 100, 105, 110, 135 and 145. If Shortest-Seek Time First (SSTF) is being used for scheduling …
Operating System |Gate-2014| Previous year question|Set-7 Read More »
Operating System | Gate-2015| 1. The following two functions P1 and P2 that share a variable B with an initial value of 2 execute concurrently. [GATE – 2015] P1() { C = B – 1; B = 2*C; } P2(){ D = 2 * B; B = D – 1; } The number of distinct values …
Operating System | Gate-2015| Previous year question|Set-6 Read More »