How the Kernel handles the fork() system call in traditional Unix and in the System V Unix, while swapping?

Unix Interview Questions

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55. How the Kernel handles the fork() system call in traditional Unix and in the System V Unix, while swapping?

Kernel in traditional Unix, makes the duplicate copy of the parent’s address space and attaches it to the child’s process, while swapping. Kernel in System V Unix, manipulates the region tables, page table, and pfdata table entries, by incrementing the reference count of the region table of shared regions.

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Other Interview Questions

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• Brief about the directory representation in UNIX
• What are the Unix system calls for I/O?
• How do you change File Access Permissions?
• What are links and symbolic links in UNIX file system?
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• How does the inode map to data block of a file?
• What is a shell?
• Brief about the initial process sequence while the system boots up.
• What are various IDs associated with a process?
• Explain fork() system call.
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• Predict the output of the following program code
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• What Happens when you execute a program?
• What Happens when you execute a command?
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• How would you kill a process?
• What is an advantage of executing a process in background?
• How do you execute one program from within another?
• What is IPC? What are the various schemes available?
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• What is major difference between the Historic Unix and the new BSD release of Unix System V in terms of Memory Management?
• What is the main goal of the Memory Management?
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• What scheme does the Kernel in Unix System V follow while choosing a swap device among the multiple swap devices?
• What is a Region?
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• Is the Process before and after the swap are the same? Give reason.
• What do you mean by u-area (user area) or u-block?
• What are the entities that are swapped out of the main memory while swapping the process out of the main memory?
• What is Fork swap?
• What is Expansion swap?
• How the Swapper works?
• What are the processes that are not bothered by the swapper? Give Reason.
• What are the requirements for a swapper to work?
• What are the criteria for choosing a process for swapping into memory from the swap device?
• What are the criteria for choosing a process for swapping out of the memory to the swap device?
• What do you mean by nice value?
• What are conditions on which deadlock can occur while swapping the processes?
• What are conditions for a machine to support Demand Paging?
• What is ‘the principle of locality’?
• What is the working set of a process?
• What is the window of the working set of a process?
• What is called a page fault?
• What are data structures that are used for Demand Paging?
• What are the bits that support the demand paging?
• How the Kernel handles the fork() system call in traditional Unix and in the System V Unix, while swapping?
• Difference between the fork() and vfork() system call?
• What is BSS(Block Started by Symbol)?
• What is Page-Stealer process?
• Name two paging states for a page in memory?
• What are the phases of swapping a page from the memory?
• What is page fault? Its types?
• In what way the Fault Handlers and the Interrupt handlers are different?
• What is validity fault?
• What does the swapping system do if it identifies the illegal page for swapping?
• What are states that the page can be in, after causing a page fault?
• In what way the validity fault handler concludes?
• At what mode the fault handler executes?
• What do you mean by the protection fault?
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• For which kind of fault the page is checked first?
• In what way the protection fault handler concludes?
• How the Kernel handles both the page stealer and the fault handler?
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• 74. What is ex and vi ?
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• What is the use of ‘grep’ command?
• What is the difference between cat and more command?
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• What is the use of the command "ls -x chapter[1-5]"
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• Is it possible to count number char, line in a file; if so, How?
• Name the data structure used to maintain file identification?
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• What is redirection?
• How to terminate a process which is running and the specialty on command kill 0?
• What is a pipe and give an example?
• Explain kill() and its possible return values.