CS6200- Intro to Operating Systems Midterm exam with correct answers

CS6200- Intro to Operating Systems |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




Midterm exam with correct answers |||\\\ |||\\\ |||\\\ |||\\\




Operating System - correct answerssoftware that abstracts and arbitrates teh hardware system
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Abstract - correct answerssimplify what hardware looks like
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Arbitrate - correct answersmanage, oversee, and control hardware use
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OS- Abstractions - correct answersprocess, thread, file, socket, memory page
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OS- Mechanisms - correct answerscreate, schedule, open, write, allocate
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OS- Policies - correct answersLRU (least recently used), EDF(earliest deadline first)
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Separation of Mechanism and Policy - correct answersimplement flexible mechanisms to
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support many policies |||\\\ |||\\\




Optimize for the Common Case - correct answersunderstanding how the OS will be used, pick
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a policy that can be supported with this OS
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User Level - correct answersunprivileged applications, no direct hw access
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Kernel Level - correct answersprivileged, direct hardware access
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, Trap - correct answerswhen an instruction that is user level attends to do a privileged
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operation, the OS verifies if it should grant that access |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




System Call Interface - correct answersset of operations that applications can explicitly invoke
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if they want the OS to perform privileged access on their behalf
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Hot Cache - correct answersapplication accessing cache when it contains data it needs
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Cold Cache - correct answersapplication accessing a cache when it does not contain data it
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needs- it must get data from main memory |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




Monolithic Operating System - correct answersevery possible service that an application could |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




require is already part of the OS, possibility for compile time optimization but has a large
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memory footprint and is not portable/maintainable` |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




Modular Operating System - correct answerscontains a number of basic services and APIs but
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things can be added as modules. Modules can be dynamically installed depending on the
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workload. Maintainable but indirection can impact performance |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




Microkernel Operating System - correct answersonly require basic primitives like structures to |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




represent executing applications, everyhting else like file systems and device drives operate
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outside operating system kernel at the user level. Requires lots of inter process interaction (so
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microkernel supports these). Benefits are that it is small and easy to verify, but not portable |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\ |||\\\




because it is highly specialized |||\\\ |||\\\ |||\\\ |||\\\




POSIX - correct answersportable operating system interface, family of standards defined by
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IEEE to maintain compatibility between operating systems
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Process - correct answersstate of a program when executing and loaded in memory, an active
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