Topics

• Virtual Memory
• Page Table
• MMU/TLB
• Address Translation
• Page Faults
• Frames/Pages
• Single level vs multi level page table
• Calculating offsets for multi-level page table
• Pipes
• Pipe read write ends
• Writing to a zero reader pipe
• Reading from a zero writer pipe
• Named pipe and Unnamed Pipes
• Buffer Size/Atomicity
• Scheduling Algorithms
• Measures of Efficiency

Questions

• What is virtual memory?
• What are the following and what is their purpose?
  • Translation Lookaside Buffer
  • Physical Address
  • Memory Management Unit. Multilevel page table. Frame number. Page number and page offset.
  • The dirty bit
  • The NX Bit
• What is a page table? How about a physical frame? Does a page always need to point to a physical frame?
• What is a page fault? What are the types? When does it result in a segfault?
• What are the advantages to a single level page table? Disadvantages? How about a multi leveled table?
• What does a multi leveled table look like in memory?
• How do you determine how many bits are used in the page offset?
• Given a 64 bit address space, 4kb pages and frames, and a 3 level page table, how many bits is the Virtual page number 1, VPN2, VPN3 and the offset?
• What is a pipe? How do I create a pipe?
• When is SIGPIPE delivered to a process?
• Under what conditions will calling read() on a pipe block? Under what conditions will read() immediately return 0
• What is the difference between a named pipe and an unnamed pipe?
• Is a pipe thread safe?
• Write a function that uses fseek and ftell to replace the middle character of a file with an 'X'
• Write a function that create a pipe and uses write to send 5 bytes, "HELLO" to the pipe. Return the read file descriptor of the pipe.
• What happens when you mmap a file?
• Why is getting the file size with ftell not recommended? How should you do it instead?
• What is scheduling?
• What is turnaround time? Response Time? Wait time?
• What is the convoy effect?
• Which algorithms have the best turnaround/response/wait time on average