Operating Systems
Ch 2-questions and
correct answers
Describe how you could obtain a statistical profile of the amount
of time spent by a program executing different sections of its
code. Discuss the importance of obtaining such a statistical
profile. - answer ✅✅One could issue periodic timer interrupts and
monitor what
instructions or what sections of code are currently executing when
the interrupts are delivered. A statistical profile of which pieces of
code were active should be consistent with the time spent by the
program in different sections of its code. Once such a statistical
profile has been obtained, the programmer could optimize those
sections of code that are consuming more of the CPU resources.
, Describe three general methods for passing parameters to the
operating system. - answer ✅✅a. Pass parameters in registers
b. Registers pass starting addresses of blocks of parameters
c. Parameters can be placed, or pushed, onto the stack by the
program, and popped off the stack by the operating system
How could a system be designed to allow a choice of operating
systems from which to boot? What would the bootstrap program
need to do? - answer ✅✅Consider a system that would like to
run both Windows
XP and three different distributions of Linux (e.g., RedHat,
Debian, and Mandrake). Each operating system will be stored on
disk. During system boot-up, a special program (which we will call
the boot manager) will determine which operating system to boot
into. This means that rather initially booting to an operating
system, the boot manager will first run during system start-up. It is
this boot manager that is responsible for
determining which system to boot into. Typically boot managers
must be stored at certain locations of the hard disk to be
recognized during system start-up. Boot managers often provide
the user with a selection of systems to boot into; boot managers
are also typically designed to boot into a default operating system
if no choice is selected by the user.
In what ways is the modular kernel approach similar to the
layered approach? In what ways does it differ from the layered
approach? - answer ✅✅The modular kernel approach requires
subsystems to interact
Ch 2-questions and
correct answers
Describe how you could obtain a statistical profile of the amount
of time spent by a program executing different sections of its
code. Discuss the importance of obtaining such a statistical
profile. - answer ✅✅One could issue periodic timer interrupts and
monitor what
instructions or what sections of code are currently executing when
the interrupts are delivered. A statistical profile of which pieces of
code were active should be consistent with the time spent by the
program in different sections of its code. Once such a statistical
profile has been obtained, the programmer could optimize those
sections of code that are consuming more of the CPU resources.
, Describe three general methods for passing parameters to the
operating system. - answer ✅✅a. Pass parameters in registers
b. Registers pass starting addresses of blocks of parameters
c. Parameters can be placed, or pushed, onto the stack by the
program, and popped off the stack by the operating system
How could a system be designed to allow a choice of operating
systems from which to boot? What would the bootstrap program
need to do? - answer ✅✅Consider a system that would like to
run both Windows
XP and three different distributions of Linux (e.g., RedHat,
Debian, and Mandrake). Each operating system will be stored on
disk. During system boot-up, a special program (which we will call
the boot manager) will determine which operating system to boot
into. This means that rather initially booting to an operating
system, the boot manager will first run during system start-up. It is
this boot manager that is responsible for
determining which system to boot into. Typically boot managers
must be stored at certain locations of the hard disk to be
recognized during system start-up. Boot managers often provide
the user with a selection of systems to boot into; boot managers
are also typically designed to boot into a default operating system
if no choice is selected by the user.
In what ways is the modular kernel approach similar to the
layered approach? In what ways does it differ from the layered
approach? - answer ✅✅The modular kernel approach requires
subsystems to interact
