Operating Systems Final Exam Review Topics Paging Virtual

Operating Systems Final Exam Review

Topics • • • Paging Virtual Memory File Systems I/O Devices Project 3: Macro Shell

Fill in the Page Table 0 1 Page 0 2 Page 0 0 Page 1 1 Page 2 2 Page 3 3 Logical Memory Page Table 3 Page 2 4 Page 1 5 6 7 Page 3 Physical Memory

Fill in the Page Table: Answer 0 1 Page 0 2 Page 0 0 1 Page 1 1 4 Page 2 2 3 Page 3 3 7 Logical Memory Page Table 3 Page 2 4 Page 1 5 6 7 Page 3 Physical Memory

Draw Arrows Offset Page 0 Page 1 010 011 00 01 011 Page 2 100 01 11 100 101 10 00 101 Page 3 000 110 110 001 0 Page 111 Logical Memory 0 1 0 Frame Page Table 1 1 001 010 111 Physical Memory

Draw Arrows: Answer Offset Page 0 Page 1 010 011 00 01 011 Page 2 100 01 11 100 101 10 00 101 Page 3 000 110 110 001 0 Page 111 Logical Memory 0 1 0 Frame Page Table 1 1 001 010 111 Physical Memory

Virtual Memory • • Page faults – What is a page fault? – What happens during a page fault? Page replacement algorithms – What is Belady’s anomaly? – How does the OPT algorithm work? – How does LRU work? – What are some LRU approximations?

Virtual Memory • Thrashing – What is thrashing? – What is a working set? • Paging tradeoffs – How does the page size affect performance?

File Systems • • Concepts – What is the file system abstraction (user view)? Implementation – Files + + What is some of the info required to store a file? What is an I-node? An linked-list w/index (FAT)? – Directories + + How are directories stored? What information does a directory have?

File Systems • Storing files (aliases) – What is a soft-link? A hard-link? Difference? • Disk management – How do you keep track of free blocks? – What do you do with bad blocks? – What is a partition?

I/O Devices • Hardware – What is DMA? – What are some IO device types? • Software – What is an interrupt handler? – How does it work?

I/O Devices • Disks – What is the performance based on? – What is the “Elevator” algorithm? • Clocks – How does a clock work?

Project 3: Macro Shell • Sockets – What is a socket? • Connection setup – How do you connect? • Send and receive – How do send and receive interact?

Project 3: Macro Shell • • Server – What does the socket code look like? – What is a concurrent server? (Project 4) – What is a non-concurrent server? (Project 3) – What possible errors might the server see? Client – What does the socket code look like? – What possible errors might the client see?