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4/22/12 2012 by Joseph

CSE120: Principles ofOperating Systems

Final Review SessionKevin WebbUniversity of California, San DiegoMarch 21, 2012

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Plan for Tonight

General exam info

Brief list of topics we covered Not exclusive

Generate discussion

Top 5 missed midterm questions

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Final Exam

Thursday, March 22, 3:00pm

Cumulative

Roughly 1/3 pre-midterm, 2/3 post-midterm

~60 questions

Same format as midterm

Bring:

SCANTRON ParSCORE X-101864-PAR-L 2012 by Joseph 33

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Processes

What is a process?

Scheduling

Synchronization Inter-process communication

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Memory

Memory management

Physical vs. logical vs. virtual

Segmentation, paging Page replacement

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File Systems

File system interface

Name space, directories

File system structure Block allocation and management

Block cache

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I/O

Structure of I/O system software

Functionality of layers

Interoperation Device drivers

Buffering

Why (and why not) buffer

Where to buffer

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Protection/Security

General domain/resource protectionmodel

Capability lists vs. access control lists Protected subsystems

Attacks on security

Cryptography

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Networks/DistributedSystems

What is a protocol?

Network protocol layers

The Internet Distributed systems vs. centralized

systems

Fundamental distributed algorithms

Problems: Byzantine Generals,Black/Red hats

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Programming Assignments

Context switching

Scheduling policies

Synchronization

Threads

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#5 (49%)

The advantage of kernel-levelthreads over user-level threads isthat:

(A) the kernel doesnt need to knowabout kernel-level threads

(B) kernel-level threads use less

resources than user-level threads (C) kernel-level threads can be assigned

to difference CPUs

(D) kernel-level threads share the same 2012 by Joseph 1111

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#5 (49%)

The advantage of kernel-levelthreads over user-level threads isthat:

(A) the kernel doesnt need to knowabout kernel-level threads

(B) kernel-level threads use less

resources than user-level threads (C) kernel-level threads can be

assigned to different CPUs

(D) kernel-level threads share the same 2012 by Joseph 1212

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#4 (37%)

Given a page-based logical address(p, i) of 32 bits, if the size of the pagetable for each process is 8 MB

(assume page table entries use 4bytes), how many bits are there inthe offset i?

(A) 10 (B) 11

(C) 12

(D) None of the above 2012 by Joseph 1313

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#4 (37%)

Given a page-based logical address(p, i) of 32 bits, if the size of the pagetable for each process is 8 MB

(assume page table entries use 4bytes), how many bits are there inthe offset i?

(A) 10 (B) 11

(C) 12

(D) None of the above 2012 by Joseph 1414

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#3 (34%)

The advantage of Earliest DeadlineFirst over Rate Monotonic Schedulingis that Earliest Deadline First:

(A) is more efficient

(B) can guarantee a higher sum of CPUutilizations is met

(C) relies only on information aboutprocess expected utilizations

(D) none of the above

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#3 (34%)

The advantage of Earliest DeadlineFirst over Rate Monotonic Schedulingis that Earliest Deadline First:

(A) is more efficient

(B) can guarantee a higher sum ofCPU utilizations is met

(C) relies only on information aboutprocess expected utilizations

(D) none of the above

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#2 (28%)

Given proportional-share schedulingwith a quantum of 1 time unit and 3processes X = (0, 10, 25%), Y = (1,

5, 25%), Z = (3, 2, 50%), where (a, s,f) specifies a process's arrival time,service time, and fractional share of

CPU time, which process should getthe CPU at time 4:

(A) X, (B) Y, (C) Z

(D) more than one are deserving 2012 by Joseph 1717

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#2 (28%)

Given proportional-share schedulingwith a quantum of 1 time unit and 3processes X = (0, 10, 25%), Y = (1,

5, 25%), Z = (3, 2, 50%), where (a, s,f) specifies a process's arrival time,service time, and fractional share of

CPU time, which process should getthe CPU at time 4:

(A) X, (B) Y, (C) Z

(D) more than one are deserving 2012 by Joseph 1818

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#2 (28%)

X = (0, 10, 25%), Y = (1, 5, 25%), Z= (3, 2, 50%)

T0: Run X, (X @ 100%)

T1: Run Y, (X @ 50%, Y @ 100%)

T2: Run X, (X @ 66%, Y @ 50%)

T3: Run Z, (X @ 50%, Y @ 33%, Z @100%)

T4: Xs ratio: 50/25 = 2, Ys ratio:

33/25 = 1.32, Zs ratio: 100/50 = 2. 2012 by Joseph 1919

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#1 (16%)

Which of the following causes themonitor lock to be released:

(A) if a process calls Wait from within themonitor

(B) if a process calls Signal from within themonitor

(C) if the last process inside the monitor isunblocked

(D) all of the above

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#1 (16%)

Which of the following causes themonitor lock to be released:

(A) if a process calls Wait from withinthe monitor

(B) if a process calls Signal from within themonitor

(C) if the last process inside the monitor isunblocked

(D) all of the above

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#1 (16%)

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Q & A

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