Unix 面试题与答案
相关差异对比
问题 86. What does the swapping system do if it identifies the illegal page for swapping?
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.
问题 87. What are states that the page can be in, after causing a page fault?</SPAN><SPAN class="answers">
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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?.
问题 88. In what way the validity fault handler concludes?
It sets the valid bit of the page by clearing the modify bit.
It recalculates the process priority.
问题 89. At what mode the fault handler executes?
At the Kernel Mode.
问题 90. What do you mean by the protection fault?
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.
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