• Placement Questions
• /
• UNIX

Frequently Asked UNIX interview questions and answers for freshers Page 3

(#M40029569) UNIX QUESTION unix Keep an EYE

Q. For which kind of fault the page is checked first?

A. The page is first checked for the validity fault, as soon as it is found that the page is invalid (valid bit is clear), the validity fault handler returns immediately, and the process incur the validity page fault. Kernel handles the validity fault and the process will incur the protection fault if any one is present.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

(#M40029568) UNIX QUESTION unix Keep an EYE

Q. How the Kernel handles the copy on write bit of a page, when the bit is set?

A. In situations like, where the copy on write bit of a page is set and that page is shared by more than one process, the Kernel allocates new page and copies the content to the new page and the other processes retain their references to the old page. After copying the Kernel updates the page table entry with the new page number

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution Mathematical Reasoning

(#M40029565) UNIX QUESTION unix Keep an EYE

Q. In what way the validity fault handler concludes?

A. It sets the valid bit of the page by clearing the modify bit.
It recalculates the process priority.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution Blood Relations

(#M40029564) UNIX QUESTION unix Keep an EYE

Q. What are states that the page can be in, after causing a page fault?

A. On a swap device and not in memory,
On the free page list in the main memory,
In an executable file,
Marked demand zero
Marked demand fill''.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (1)   (0) Submit Your Solution

(#M40029567) UNIX QUESTION unix Keep an EYE

Q. What do you mean by the protection fault?

A. Protection fault refers to the process accessing the pages, which do not have the access permission. A process also incur the protection fault when it attempts to write a page whose copy on write bit was set during the fork() system call.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

(#M40029562) UNIX QUESTION unix Keep an EYE

Q. What is validity fault?

A. If a process referring a page in the main memory whose valid bit is not set, it results in validity fault.
The valid bit is not set for those pages:
that are outside the virtual address space of a process,
that are the part of the virtual address space of the process but no physical address is assigned to it.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

(#M40029563) UNIX QUESTION unix Keep an EYE

Q. What does the swapping system do if it identifies the illegal page for swapping?

A. If the disk block descriptor does not contain any record of the faulted page, then this causes the attempted memory reference is invalid and the kernel sends a Segmentation violation signal to the offending process. This happens when the swapping system identifies any invalid memory reference

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

(#M40029561) UNIX QUESTION unix Keep an EYE

Q. In what way the Fault Handlers and the Interrupt handlers are different?

A. Fault handlers are also an interrupt handler with an exception that the interrupt handlers cannot sleep. Fault handlers sleep in the context of the process that caused the memory fault. The fault refers to the running process and no arbitrary processes are put to sleep.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

(#M40029560) UNIX QUESTION unix Keep an EYE

Q. What is page fault? Its types?

A. Page fault refers to the situation of not having a page in the main memory when any process references it. There are two types of page fault :Validity fault, Protection fault.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution

(#M40029559) UNIX QUESTION unix Keep an EYE

Q. What are the phases of swapping a page from the memory?

A. Page stealer finds the page eligible for swapping and places the page number in the list of pages to be swapped.
Kernel copies the page to a swap device when necessary and clears the valid bit in the page table entry, decrements the pfdata reference count, and places the pfdata table entry at the end of the free list if its reference count is 0.

Asked In UNIX MAN (12 years ago)

Unsolved

Is this Puzzle helpful?   (0)   (0) Submit Your Solution