Operating Systems 2015F: Assignment 5: Difference between revisions

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'''This assignment is not yet finalized'''
'''This assignment is not yet finalized'''


#  Within a UNIX filesystem, one inode can be
#  Within a UNIX filesystem, one inode can be referred to by many different pathnames (filenames).  What is another term for these names?
  referred to by many different pathnames (filenames).  What is
  another term for these names?
#* hard links
#* hard links
#* symbolic links
#* symbolic links

Revision as of 05:10, 13 November 2015

This assignment is not yet finalized

  1. Within a UNIX filesystem, one inode can be referred to by many different pathnames (filenames). What is another term for these names?
    • hard links
    • symbolic links
    • URLs
    • all of the above
  2. A modern monolithic operating system kernel typically implements
    • scheduling \& address space management
    • some device drivers
    • a TCP/IP stack
    • All of the above
  3. An OS that is based upon a microkernel

architecture will typically:

    • have most device drivers and filesystem code run within separate userspace processes
    • have most OS code run in CPU supervisor mode
    • support loadable kernel modules
    • All of the above
  1. A typical executing application is best

described as a:

    • kernel
    • process
    • thread
    • system call
  1. When a running program X requests data from a file F whose contents are on disk, the OS will:
    • save X's current state
    • schedule a disk request for F's data blocks
    • load the state of another ready-to-run program Y (which may be X)
    • All of the above
  2. When a regular process is running on a single-CPU system, all of the following are true except:
    • The kernel is running.
    • Disks can be writing data to memory.
    • The CPU will generate an exception (software interrupt) if certain addresses are accessed.
    • The CPU is in user mode.
  3. Modern virtual memory systems:
    • Logically divide RAM into fixed-sized chunks
    • Store portions of processes on disk
    • Allocate a logical address space to each process that is distinct from the physical memory map
    • All of the above
  4. The ``dirty bit in a page table entry

indicates that:

    • A security violation has occurred
    • The corresponding page has been accessed.
    • The corresponding page has been modified.
    • The corresponding page is shared between multiple processes.
  1. An inode contains all of the following except:
    • user ID
    • filename
    • time of last data modification
    • link count
  2. When checking the consistency of a filesystem (e.g. after a loss of power), all of the following must be checked except:
    • inode reference counts
    • pointers to data blocks (in inodes or indirect blocks)
    • contents of data blocks of regular files
    • block free list
# If a system automatically boots into a defective kernel (e.g., one that crashes on startup), you can recover the system by:
    • Select a different kernel in the bootloader
    • Perform a soft reboot of the system
    • Perform a hard reboot of the system
    • Press Alt-SysRq-R
  1. Virtual memory is prohibitively expensive on a system that lacks a TLB because
    • Every memory access then requires a system call.
    • The page table has to be checked on every memory access
    • The process table has to be updated on every tick interval.
    • None of the above