# Can a page fault be generated due to the absence of the page of inner page table , table for multi level paging ?

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Consider, 2 level paging , with Process P, Inner page table PTi, and outer page table PTo.

Now we know that P and PTi  are divided in various pages but PTo is in 1 page only.

So in order to run process P, we need few pages of P , few pages of PTi and complete PTo in main memory.

If PTi asks for a page of P which is not present in main memory , then thats a PAGE FAULT and that particular page of P will be loaded in.

Now the question is :

Q1)  If PTo asks for a page of PTi which is not present in main memory , then ,is that also a PAGE FAULT ?

If YES, then can it be extended to all k page tables ( for k-level paging) where PTk is the outermost page table of within 1 page.

If No, then why ?

Q2) If answer to above question is YES, then consider the two images below:

Case 1 gives formula for EMAT , in case of no page fault ,which is correct.

EMAT formula considering page faults( as per Q1 assuming YES)  is given in CASE 2

but most of the EMAT formulas online and in books gave formula given in  CASE 3

Why they have used formula given in case 3 and not in case 2 in case of page faults?

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Consider a computer system using 2-level paging with TLB. The logical address supported is 32 bits. The page table is divided into 512 pages each of size 1KB. Page table entry size at 1st level is 2Bytes and that at the second level is 4 Bytes each. What is the ... For first level PT)+$512*1KB$(At second level)=$544KB$ Is my analysis correct? Below is the visualisation what I see is happening.