Unix interview Questions and Answers for Freshers | Experienced

www.unixbuzz.com - 45> In Unix How the Kernel handles the fork() system call in traditional Unix and in the System V Unix, while swapping???? Ans: In Unix 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. 46> Difference between the fork() and vfork() system call in Unix ?? Ans: In Unix fork() system call the Kernel makes a copy of the parent processes address space and attaches it to the child process. But the vfork() system call do not makes any copy of the parent’s address space, so it is faster than the fork() system call. The child process as a result of the vfork() system call executes exec() system call. The child process from vfork() system call executes in the parent’s address space (this can overwrite the parent’s data and stack ) which suspends the parent process until the child process exits.