Paging and virtual memory

Question

If there is 2 or more level paging for processes, is it possible to have more than 1 page fault while accessing any single addressable unit(byte or word) ?

Answer 1

No. Because page table access never page faults. All the page table entries will always be in main memory.

But a single instruction can cause multiple page faults if it involves multiple memory operands.

Comments

So this means all the inner page tables of  process will reside in physical memory all the time to prevent successive page faults while performing any fetching operation.

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Yes. If any inner level page table is not used by the process then it won't be loaded. That's why we have questions where the process memory usage will be given and asked for page table size.

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@Arjun  sir, as per me, if we have atleast one page from each level, then we can run the process, then page fault may occur.

But you are saying all pages of page table should be in memory, this lead to contradiction my concept.

Where i am going wrong ?

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I have exact same doubt sir.

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@Shaik Masthan What do you mean by "one page from each level"? In each level we have page tables. Now, number of page tables used by any process varies and they can have different number of page tables in each level. But, if a process uses say 100 page tables across all levels, then these 100 must be present in physical memory when that process is running. Or page table access can NEVER page fault. Because then the normal page fault mechanism cannot work. I'll discuss this soon, the slides for this must be on GO classroom. 

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the slides for this must be on GO classroom

sir, i will check it there

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but sir we load only required part of process  to increase degree of multiprogramming ,so in between execution page which is not loaded previously need to be loaded .so why not then page fault???

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doubtful for the answer Sir

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What is your doubt?

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In case of an instruction that is split into many words, we may have multiple page faults, but for a single word, we can have a max 1-page fault as when we access all the  PT are in memory?
Is that the essence of your answer?